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FAQs on the Piranhas 1

Related Articles: Piranhas, Serrasalmine Fishes, Characoids/Tetras & Relatives Feeding Feeder Goldfish,

Related FAQs:  Piranhas 1, Piranhas 2, & FAQs on: Piranha Identification, Piranha Behavior, Piranha Compatibility, Piranha Selection, Piranha Systems, Piranha Feeding, Piranha Health, Piranha Reproduction, & Piranhas and Relatives, Feeding "Feeder" Goldfish, Pacus, Silver Dollars,

Re: piranha fish 1/13/11
hey Neale,
here's my questions:
1. How did you become an expert in the field of fish Including your education and experience?
<I'd always been interested in sea life, enjoying especially to the county of Cornwall on the southwest coast of England where I explored tide pools and sandy beaches. When I was 14 my science teacher gave me an aquarium to look after during the summer vacation, and from that point onwards I was hooked! At university where I was studying marine zoology the department there asked me to look after their two 200 gallon display tanks, and in the process I ended up trying out sorts of different types of fishkeeping, from reef tanks to coldwater marines, though brackish water fish and Central American cichlids became my favourites.>
2. What do you do on a day to day basis in your position?
<I'm a freelance writer for various fishkeeping publications including regular articles in the major US and UK magazines. I also write for a number of commercial websites focused on the hobby, some towards the retail end, others aimed at hobbyists. You've contacted me through WetWebMedia, one of the biggest hobby sites and a place I spend anything up to an hour per day answering questions from hobbyists worried about sick fish.>
3. Why do piranhas change colors while spawning?
<Presumably for communication, though the fact Piranhas commonly inhabit murky water must make this mode of communication unreliable much of the time. Fish usually don't make sounds (though some do) so anything one fish needs to "say" to another is frequently done through visual cues. Often there's a combination of colours and movements rather than just colours on their own. So a male fish will not only darken or brighten its colours to display to a female, but also stiffen his fins, flare his gills, waggle his tail, or whatever.>
4. Of the 1200 species of piranhas, <Mmm, there are only a few dozen species of Serrasalmines... do you mean Characids-oids? RMF>> which type would you consider the deadliest?
<I'm not sure any of them is particularly deadly, though a very few can be dangerous. In fact Piranhas are of most significance to humans as food -- they are routinely fished for in South America, often by young children using very simple home-made fishing tackle. It is actually very rare for wild Piranhas to attack humans, and they only do so in certain places at certain times, and the locals know to avoid those places when there's a risk. When it comes to being dangerous, Piranhas don't come anywhere near such terrifying animals as Honey Bees or Domestic Dogs in the number of deaths they cause per year! In the Amazon Region, the locals are far more nervous about Stingrays which may not be predators but are equipped with strong defensive stings, and while not normally fatal they are incredibly painful. And of course every once in a while the victim doesn't get better, perhaps because of a combination of envenomation, trauma, and shock, and he or she dies, much as happened in the case of Steve Irwin. From the perspective of the aquarist though the Piranha most likely to bite is probably the Black Piranha, a rather grumpy loner that will view the aquarist's hands as a threat to its territory. Such fish need to be confined to one end of the tank using a net or screen before you can work in the tank safely. The Red Belly Piranha rarely bites but it does happen, and because it is by far the most commonly kept species, it is probably responsible for the most injuries. The ones most likely to cause serious harm though might be the vegetation Pacus; these can and do bite, and their incredibly strong jaws mean they can crush bone. In all cases, aquarists who've been bitten need to get medical attention afterwards because of the high risk of secondary infection.>
5. Are piranhas predators only as adults or can they be predators when they are young?
<They're predatory throughout their lives, but in many cases their diet varies depending on the time of the year. Something like a Red Belly Piranha may eat insect larvae when they're plentiful, small fish at other times of the year, and fruits and seeds at another time of the year.
Piranha are never 100% carnivorous any more than Pacu are never 100% herbivorous. All the Piranha family of fish fall onto a spectrum where their diet includes meat, fish, insects and fruits/seeds, but with the precise ratios of these varying among species and depending also on the time of year.>
6. When piranhas spawn, why do they make a territory?
<In those species about which spawning in the wild has been observed, it appears the males guard the eggs and fry, at least until the fry are free-swimming. As such, it's in their interest to secure a patch with a safe place for their offspring. There will usually be tremendous competition for such patches, and only the strongest males will be able to hold onto a nesting site long enough to spawn and raise the fry.>
7. What is the most unusual thing that happened to you at your job?
<Perhaps the most memorable at least was doing a dissection of a rare, deep sea shark called a Frilled Shark (Chlamydoselachus anguineus). This chap was about six feet long and had been brought up by a deep sea trawler. Of no value for food, it was given to the university I was at, where it was frozen and largely forgotten about. After a few months I was given this thing to dissect. Because only a few are seen each year, this was going to be a real treat. Now, sharks have very leathery skin, so opening them up is hard. You often have to start with a pretty forceful plunge of the knife! I did this, and was sprayed with horrible fountain of oily, smelly shark soup. What we'd not realised was that even kept cold enough to defrost it without having it go off, the enzymes inside the shark worked very effectively at digesting its tissues. Ordinarily enzymes need to be quite warm to work properly, but deep sea fish live in water that's barely above freezing, and they have special enzymes. End result -- a pre-digested shark! Needless to say it took a while before anyone would come within a mile of me!
Cheers, Neale.>

piranha fish... Questions   1/5/11
Hi crew,
My name is Drew Degen and I'm a freshman at Glenbrook North High school in Northbrook IL. I was wondering if you guys knew anything about piranhas because I'm doing a project on piranhas in my science class and I'm interviewing 2 people about piranhas (the first was the Shedd). I was wondering if you had the time if you could answer a few questions on piranhas for me. I'm planning on asking about 4-5 questions.
Thanks for your time, Drew Degen
<Sure Drew, send 'em along. Cheers, Neale.>

Red belly piranha, hlth., beh.   ~ 01/12/09 Hello I was wondering if you could help me with a worry of mine. I have four red bellies about 5 in in length and they have been doing fine up until about 4 days ago. They are acting normally but they lose their vibrant red bellies at night I never noticed it before maybe it's been that way at night but I never noticed it. Their water temp Is maintained at 82 F and their water ammonia and nitrate levels are normal. I did however take out a piece of driftwood that sit in the middle of the tank but they were too big to swim into it so they never used it. Any ideas? Joel <Joel, it is perfectly normal for Pygocentrus nattereri to change colour at night. They also change colours as they mature. It is quite possible that they've always had different colours at night, but they're getting to an age now where these differences are become more pronounced. You're keeping your fish a little on the warm side for this species, though piranhas from the rather warm Rio Xingu do indeed like things a bit hotter than otherwise. If you turn down the thermostat a notch, not only will there be more oxygen in the water, but your fish will also live longer and be less aggressive towards one another! The 23-25 C, 73-77 F is just fine for them. If in doubt, visit Fishbase to check the temperature preferences of your fish; for some reason I cannot fathom, a crazy proportion of aquarists keep their fish far too hot, wasting money and compromising health. For what it's worth rather than worrying about bogwood, use plants to provide shade for these light-phobic fish. Tall plants, such as giant Vallisneria and big Java ferns are ideal, and floating plants with long roots like Amazon Frogbit work very well too. Piranhas are primarily dusk/dawn fish, and they despise bright light. Cheers, Neale.>

Re: Red belly piranha  ~ 01/12/09 Thanks Neale I appreciate the help! A lot of websites for piranhas suggest 80+degrees but I see the logic in your explanation. This might be a silly question but is it at all possible for a red devil cichlid to cohabit a large enough tank? And if so what size is needed for such a thing? Joel <Hi Joel. There are very few Piranha web sites I trust. Too many people keep these wonderful fish badly. Like Rottweilers and pit-bull terriers, they have this image of brutality and so brutal people end up keeping them. But just like those dogs, kept properly, Piranhas are fascinating and rewarding pets (as well as very beautiful, in their way). Anyway, one of the best sites is the Oregon Piranha Exotic Fish Exhibit site, a semi-academic site with a ton of good information. Here's their Pygocentrus nattereri page. They report wild fish tolerating remarkably cool conditions, for short periods at least, but do recommend low 20s C (low to mid 70s F) as the optimal temperature, and this meshes with what Fishbase reports too. By the way, don't change the temperature all at once, but just knock it down a degree every couple of weeks, and watch how your fish react. http://www.angelfire.com/biz/piranha038/nattereri.html Now, as for tankmates. I have seen Piranhas cohabit with Convict cichlids, but what we see in these situations tends to be a dominant cichlid that terrifies a small group of Piranhas. Because Piranhas are nervous at the best of times, I just don't see any mileage in that, and would recommend keeping the Piranhas on their own. Sometimes Suckermouth catfish like Plecs coexist, but that usually depends on the Plec being their first, so the baby Piranhas grow up with it, accepting it as part of the furniture (rather than food!). Adding a catfish to an established tank is just too risky, and I don't need to tell you that Piranhas have a lot of firepower at their disposal should they decide to turn on a tankmate. When all is said and done, my advice is to keep 'em alone. A nicely decorated Piranha tank is a thing of beauty, just as it is. Cheers, Neale.> Re: Red belly piranha Thanks for all the help Neale you've helped a ton Joel <Happy to help. Cheers, Neale.>

Tank questions about 2 different tanks... Endogenous algae prob.s/SW, Piranha tank plant sel.   04/14/2008 Hello, <Hi there> Tank- 200 gal (7'Lx2'Wx2'H), 130+ pounds LR, 40 gal refugium plus a large hang-on refugium, 3-XP3's canisters, 2 Rio 2100 (694gph) and 3 Penguin 1140 (300gph) power heads on sides and back of tank. And a Coralife 220gallon Protein Skimmer.\\ <Mmm, I'd upgrade> Fish- 8" Russell's Lionfish, 3 triggers Niger, Humu, and a Bursa all 4", 2 yellow Tangs 4", 5" Foxface Lo, and a 13" Wolf Eel. I also have a lot of Red Mushrooms, Button coral, and 2 different leathers. And I do a 30gal water changes (w/ RO water) every 2-3 weeks. This tank has been up and running for over 3 years. I get brown algae out breaks, I also have green (hair) fuzz algae on most my rocks and back and sides of tank. I was told since I clean my canisters once a month (not often enough), <This is so... I'd clean them at least weekly> that the entire gunk they collected just creates more Nitrate, lots. What I should do is over time keep the skimmer and get rid of the canisters and add more power heads for more current so that the LR (and refugiums) can do there jobs. (20gph times your tank size ((4000gph)), so I need 1720gph more in my aquarium) Does that sound alright? <A beginning...> I do use Chemi-pure and Phos-Zorb in each filter. I also test water a Reef Master Test kit. My Nitrate and Phosphate are both low and are in the safe ranges but they both show up, always have. <These measures of nutrient ability are not entirely "accurate"... the real bulk of this matter is being expressed, taken up by the algae and BGA (the brown stuff)> I also have allot <Won't correct this time... a lot> of this bright yellowish-greenish sponge (Cecilia I think) <Not this feminine appellation; though a fave Simon and Garfunkel tune> growing on my LR. Is it bad or good? <Mmm, more of the latter> I'm setting up a 90gal (4'Lx18"Wx2'H) FW, I'm going to get 3 baby Red Belly piranhas. I do plan on having plants growing out the top of my aquarium. Just the roots will be in the tank. So with that said should this set-up be OK for 2-3 adult size Red Belly piranhas in the long run? And what kind of plants besides Bamboo should I use? <Yes and if only one, my fave, Ceratopteris> Thanks for all your advice Matt Owens <Welcome. I'd get a better skimmer, perhaps ditch the canister filters altogether, or clean out weekly as stated... add more/new live rock... and likely skip the Serrasalmines (too skittish and boring as you'll see)... Cheers, Bob Fenner>

My new tank, poor FW mix of lvstk., ich   1/31/08 hi, Currently I have 55G tank which contains four 2inch gold fish , six 2inch koi carp , two 4inch koi carp , six 2inch angels and one 25cm Pleco. I know it's a small tank ,that's why I am building a new 200G tank. <Very good.> I am thinking about buying 2 red bellied piranha. Is that a good idea?. <To mix with these fish? Absolutely not. In addition, most of the common piranhas in the trade, including Pygocentrus nattereri (the Red-bellied Piranha), are essentially solitary fish in aquaria. Their social behaviour in the wild is extremely complex and difficult to replicate in captivity. Juveniles may school together, but adults only form schools under certain conditions, and when mature the males are territorial and ultimately guard nests and eggs. Unless kept in BIG aquaria where there are AT LEAST SIX specimens, piranhas simply don't work in groups. The dominant male systematically harasses and eventually kills the other fish. The flip side to this is that single piranhas are nervous and scared of their own shadows! They are very VERY boring pets.> Is there any kind of fish that I can add with the piranha's? <None.> Right now I have one more problem , one of my koi carp is scratching ,what should I do . <Likely Whitespot/Ick and should be treated accordingly.> Is it necessary to remove live plants before adding any medicine into the system?. <Not normally, no.> One of my koi carp has full red body with small white patches in the middle, is that what u call white spot disease. <Sounds like it.> And last I want u to suggest a suitable filter for my new 200G tank (please mention the company name also) <The ideal filter will vary. If the tank contains just fish and no plants (or maybe floating plants or plants attached to wood) then an undergravel filter can work very well. Use at least two powerheads to get a gravel bed this size working properly. Alternatively, you can use one or more external canister filters. These work better with tanks that contain plants. In either case, the brand of filter doesn't matter much, though some brands, notably Eheim, have a good reputation for reliability and value over the long term. The main thing is turnover. For large fish like yours, you want the powerheads or filter pumps to produce at least 6 times the volume of the tank in turnover per hour. So in your case, the pumps should add up to 6 x 200 = 1200 gallons per hour.> thanks a lot Mathew <Cheers, Neale.>

Old piranha -- 07/18/07 Hello! <Hi.> My husband and I have a piranha that we believe to be about 10 years old. He's kept in a 55 gallon tank and is the only fish in there. He has always been in good health, but about three weeks ago he started swimming facing down. Then a little over a week ago he started to lay on the bottom of his tank and not swim at all. His coloring is still good, but he barely moves during the day. We noticed that at night he tends to swim around a lot more. Could it be possible that the water in his tank is too hot? We have AC in our house, so his tank is usually as warm as 82-84 degrees. <Temperature is ok, 86 F is the upper limit for piranhas, 79 F the lower limit.> Is this what is causing him to act so sick or do you suppose he has some other illness or is simply getting old? <Likely the latter, while they can live for more than 20 years, 10 years is not a small age for a captive specimen. Also check your nitrates and pH to exclude those two environmental factors. You may want to introduce some floating plants to make him feel more comfortable during day. Usually they live in small groups, but I would not add further specimens to your old fish. Have a look at: http://www.wetwebmedia.com/FWSubWebIndex/piranhafaqs1.htm.> Thank you! <You are welcome. Good luck with your piranha. Marco.>

Piranha system size --  7/11/07 Hi, I currently have 17 Piranhas in my 45 gallon Aquarium all at about an inch each, because my cousin recently bought the fish but he had to move out of his apartment. The tank looks very overcrowded <is> and I am definitely interested in purchasing a larger aquarium. If I was to get a 100 gallon how many of these fish could I keep and also how large of an aquarium would I have to get in order to keep all of these guys together? <There are several different Piranha species with different territoriality and size, but I assume you have the most common: Pygocentrus nattereri. In a heavy planted and well filtered tank somewhat resembling their natural habitat 20 gallons per fish are the minimum in my opinion. In the usually seen systems with less plants and lots of open space 40-50 gallons would be needed. 5 can be kept in a well planted tank of 100 gallons if pristine water quality can be established, about 350 gallons are needed for the entire group you have. What a tank! Have a look at http://www.wetwebmedia.com/FWSubWebIndex/piranhas!.htm and the linked FAQs above. See fishbase.org for pictures of more species.> Thanks ! <Cheers, Marco.>

RB Piranha comp.   - 04/20/07 Hi Bob, <Well, it's actually Neale, but Hi anyway!> My son purchased some red bellied piranhas (Babies). <I trust he bought a book about piranhas first? These are neither easy fish nor ideal fish for beginners. They are also rather large and basically boring pets. Great for people with space and experience, but terrible for children.> However two smaller ones keep attacking the larger one. <Absolutely normal. As any book about piranhas will tell you, these are intensely hierarchical schooling fish that live in swarms of hundreds of specimens. When kept in twos and threes their normal behaviour is short-circuited and the dominant fish *invariably* ends up bullying the one at the bottom of the social order. This is repeated as each fish below the "boss" dies, until you have a single specimen. Being schooling fish, they are very unhappy kept alone, and this singleton is nervous, flighty, and not at all entertaining.> First time they ate his fins, tail and took out an eye (hence his name eyeball). I got a divider so that eyeball could recover which he did. Today however, the two smaller ones again attacked eyeball eating his fins and tail. Eyeball can not stay in an up right position, so again I put in the divider and have eyeball suspended in a net in an up right position. I have kept him alive now for 11 hrs, but was wondering how long I should keep him in the net? <Well, piranhas heal very quickly when in good condition. They have to: their mating rituals (if you can call them that) involve biting chunks out of each other. But as should be glaringly obvious, there's no way that "Eyeball" can ever be kept in the same tank as the other two specimens. Oh, and it's probably a matter of time before they fight. So be sure and get three large aquaria set up, one for each piranha.> Should I keep him there till I see signs of re growth of his tail? <Yes. And also when the wounds are nicely healed. And I'd keep treating the water with something anti-microbial, such as Melafix.> I feed them plenty (shrimp, fillets, snails, krill etc...) just do not understand why they attack eyeball. <As said above: from being kept in appropriate numbers. They are doing what comes natural.> All the fish are healthy otherwise.. At this point I do not want eyeball to pass away (so much work has gone into keeping him alive) water conditions are right on target.. Not sure if keeping him in a net in the up right position is the best idea, but at least he is not laying on his side on the bottom of the tank. Any suggestions on how I can help him heal quicker so he is not confined in the net but is still up right? <Sounds to me you're doing the right things in terms of triage. But keeping him in a hospital tank is probably the best route, and actually inevitable really because this fish will have to be kept apart from the other for the rest of its life.> Thank you so very much for having a wonderful site for people to use as a reference. <No problems. Glad to help. Now please, sit down with your son and discuss the future. A "safe" number of specimens is 4 in a 75 gallon tank. You can keep more than that, adding around 20 gallons per specimen. If this isn't on the cards, then your son may need to think about re-homing these fish. If he wants something piranha-like, Exodon paradoxus is easy enough to obtain, but smaller, and just as fierce; it's also prettier and more active, and will even eat flake. Finally, please make sure he isn't using live feeder fish for food. That's a sure fire way to introduce parasites and pathogens. Goldfish and minnows also have serious nutrition problems because they contain thiaminase. The only safe feeder fish are livebearers bred at home. But with piranha you don't even need those, and your fish will be healthier given a pellet/stick staple diet carefully balanced to have all the nutrition fish need. Augment periodically with "treats" such as frozen silversides and lancefish. There are plenty of good books about piranha, and as a good mother it's up to you to teach your son about research and responsibility. Too many young boys buy piranhas because they are "scary" and then suddenly discover that, like all animals, they have needs and must be cared for properly.> Dar

Piranhas, Brackish?  2/16/07 <Hi, Pufferpunk here> Are there any species of piranha that live in brackish water conditions?  I thought at one time I had read about this stuff you put into your tank to make it kinda dark and brackish to replicate the Amazon river.  <Dark water is not brackish water.  It is the opposite.  The Amazon river is soft & acidic (low pH)--BW is hard & basic (high pH).> So are piranha's adapted to freshwater for aquariums and normally brackish or are they freshwater or do they live in both?  <Piranhas are strictly freshwater fish.  Dechlorinated tap water is fine. ~PP> PLEASE HELP

Piranha in Septic System  - 02/15/07 Hello:  I thought I'd offer some insight into the apparently wacky question posed by someone whose girlfriend had been advised to "put a piranha in her septic tank" to make it work better.  There is a commercial product called a Piranha system which is used to improve the performance of septic systems.  It doesn't use piranha fish (duh!), but rather a culture of bacteria that aggressively eats up stuff that plugs up septic systems, hence the name of the product.  So, the person's girl friend actually got good advice, just needs to distinguish between the fish and the septic system product.  (Kind of like a Plymouth Barracuda isn't something you go trolling for.) <<Ha! Thank you for this clarification. Lisa.>>

Piranha With Gill Cover Deformity Hello its Tara here. I contacted you before about the set up of my new tank and like you suggested we let the tank cycle for longer and now have our red   bellies. When we got them they didn't have any color but now have red bottom   fins They are about 4 cm long now so should they have a red belly by now We   have been giving them a varied diet. Also one of them has a slight stuck out   gill, we asked the pet store if this was an illness but they said it is probably  a slight deformity( I don't think they have a clue) so is there something I  should look up and check? < I happen to agree with the store. Deformed gill covers are not that unusual in captive bred fish. Most of the time they are culled out before they are shipped.> Other than that they are fine and I have no other worries. While they are small we have put in a Pleco to help with the cleaning of  the tank. He is massive I was just wondering if they will eventually end up eating him? < They love fins and if they think he is a food item then they will continue to pick at him. He may go into hiding and only come out at night when the red bellies are asleep.> Lastly, one more silly question when do they start getting their teeth or  are they just to small to see at the moment? < The teeth are in, they are just small.-Chuck> Thanks again. Tara

Senior Piranha  1/8/07 Hello Mr. Fenner, <Sorry Denise, not Bob--just Pufferpunk here--hope I'll do...> I was reading over your FAQ's page.  I have had "Fred" my red bellied piranha for approximately 16 years.  As of recent, I noticed him getting a spurt of swimming energy and then all the sudden falling over on his side.  It is almost like he can not keep his balance.  He will lay up against the side of the tank for hours. He breaths "heavy and fast".  Not sure if this is common in piranhas.  I want to help him, if there is something I can do.  I do frequent water changes, keep close eye on the temp, and make sure the filters are cleaned at least once to twice a week.  Is there something more I can do?  It is not like I can put him on a leash and take him to the vet?  Any suggestions? <I'd have to guess old age with this fella.  Quite a feat, keeping a fish that long!  Just keep doing what you're doing & keep him as comfortable as possible.  Might want to back off feedings a bit, as his metabolism is slowing down. ~PP> Denise in PA

Starting my tank   12/19/06 Hello, <<Hello, Tara. Tom here.>> We have just bought the jewel tank containing 190 litres and are setting it up to contain red belly piranhas. We originally wanted 3 but after reading your site discovered that its only really big enough for 2 at a push. <<Given an adult size of approximately 12 inches (30.5 cm), two of these fish would, indeed, be pushing the limit of a 190-liter (50-gallon) tank, Tara. Adequate cover and low lighting should be provided to keep 'skittishness' to a minimum.>> We also would like to know if it is essential to test the water pH before putting in the fish. <<Do yourselves this favor, Tara. Visit the pet shop and find out what the pH is of the water that your future pets are currently being kept in. Piranhas come from waters that are soft and acidic in their natural habitat with the pH below neutral (7.0). This really isn't as critical as trying to avoid introducing them to a tank that's far off from what they've been acclimated to, however. Stability is the key factor here.>> The tank has been set up for nearly 2 weeks now at the right temp and I don't want to be ignorant by hurting the fish by just putting them in without it being perfect. <<pH is not going to be your only concern here. In fact, ammonia and nitrite levels are going to be far more of a concern right now than pH will be. Unless you've taken some extraordinary measures to speed up the 'cycling' of the tank, I doubt that your tank is more than one-third to one-half through the cycling process after only two weeks. Test for ammonia and nitrite (both should be zero) and check your nitrate levels as well. Nitrates, by way of explanation, are the 'end product' of the nitrifying process. If ammonia and nitrites are zero but nitrates are also zero, your tank isn't ready for live fish. Your pet shop can test a sample for you if you don't have a test kit already. Personally, I highly recommend that you get one so that you can do your own testing. Shops have a tendency to tell folks that levels are 'safe' without being specific about what this really means. Better in the long run for you to know 'exactly' what your readings are. More convenient, too.>> Also, what would be your best recommendation to start feeding them as they are only about the size of a 2p when we get them. <<Thawed mussels, prawns, shrimp and fish will be appreciated but there are processed foods, in the form of pellets, for carnivorous fish like Piranhas that they may also take to in order to vary their diet. You might find that early on they'll also accept flake food. (By the way, '2p', for the benefit of our American readers who don't have one readily available, is about the size of a Susan B. Anthony dollar, which is nearly exactly the size of an American quarter. That one might have worked better if George Washington and Ms. Anthony hadn't look so much alike. :) )>> (Although, my husband really wants to feed them live food on occasion. I suppose it's a bloke thing). <<Advise your husband to keep this to a minimum, Tara. Feeder fish have little nutritional value and can be a source of disease. You and I know he's going to do it anyway but, it's not without risk to your pets.>> Thanks for your help Tara <<Consider giving your tank another fortnight (I don't get a chance to use that term very often) to cycle completely and really consider the test kit I mentioned. Uneaten food, if there is any with Piranhas, will need to be removed to prevent your water conditions from becoming toxic. Good idea to stay on top of this as best you can. Good luck with your new additions, Tara. Cheers. Tom>>

Keeping Piranhas with Tropical Fish   10/5/06 Hey, <Hi Ryan, Pufferpunk here> I have a 55 gallon tank. Currently there are 2 small tetras, feeders and a 4 to 5 in Oscar. I am about to put in six 2in piranhas (red-bellies). <HUH?  Are you joking?  Those piranhas, at any size, will eat the tetras (eventually eaten by the Oscar) & bite chunks out of your Oscar!  That tank is just large enough for the Oscar, when it grows.  Don't add any more fish to his tank.  Even a 55g is a bit tight for a full-grown Oscar.> Should I be worried that the larger Oscar might kill the small piranhas?  Likewise, will the piranhas to better if introduced to the tank with no other fish present? <The piranhas should be introduced into a separate tank.  The Oscar will soon eat the tetras or any other fish it can fit into it's HUGE mouth.  I do not recommend feeding your Oscar feeders & find homes, or return the ones in his tank.  They carry disease.  Get him earring pieces of fish, scallops (or whatever you can find in the fish dept of your grocery store that he likes), krill & Cichlid pellets.  ~PP> Thanks, Ryan

Water Conditions for Red Belly Piranha - Natteri Species   9/17/06 Hi guys - love reading your site, really excellent info! <<Hello, Matt, and thanks. Tom with you, by the way.>> I have few questions please on the best conditions for keeping red belly Piranhas. I have just set up a new 275 litre tank and purchased an Eheim 2128 external thermofilter (to my wife's great dis-pleasure due to the cost!) to do the filtering (filled with Eheim Substrat pro media as Eheim recommend). <<Excellent choice - and I understand your wife's consternation. Does this count as this year's birthday AND Christmas present to yourself? :)>> The tank is in the process of fishless cycling using Waterlife's Biomature (I will not even consider adding any Piranhas until both ammonia and nitrite are zero as I have the fishes best interest in mind!). <<Always a great pleasure to hear this sort of thing from our readers!>> I have read Bob's recommendation of 80 litres of water per Piranha so plan to buy 3 baby piranhas that can permanently grow up in the tank. <<Sounds good, Matt.>> My questions are around the water parameters for the Piranhas - my tap water PH is 8.0 which seems a bit too high for Piranhas as I think they prefer acidic water - is it OK to purchase a PH lowering product like Nutrafin PH - to get the PH down to just below 7.0 or just leave alone? <<Leave it alone, Matt. It'll more dangerous to toy around with this than it will be to allow your new fish to acclimate/adapt to the higher pH. Perhaps some driftwood would be advantageous here, but chemically treating your water is problematic at best.>> Also my tap water has 25ppm Nitrate - what can I do about this or is this acceptable? (I plan to have lots of live plants so is this level of nitrate beneficial for them?) <<It can be, Matt...with a proviso, i.e. "string attached". Aquarium plants will absolutely use nitrate but it's not their first nitrogen choice - if plants make choices, that is. The "trick" here is two-fold. By keeping ammonia levels at zero, first, you deprive the plants of what they look to initially for a source of nitrogen. This means keeping water conditions pristine, which I suspect is not going to be an issue in your case from what I've been able to determine. Second, healthy, fast-growing plants are a real "plus" here as their nitrogen requirements are greater. Absent a usable supply of ammonia/ammonium, the plants will turn to nitrates for their nutrient requirements. In short, you'll need to "force" your plants to use the nitrates. Now, if you wanted to completely jeopardize your marriage, you could investigate a RO (reverse-osmosis) system for water changes but you didn't get that from me! :)>> I would really appreciate your advice - I want to get everything right before I consider buying the fish! <<An admirable aspiration, Matt, and one that we here at WWM fully support.>> Regards, Matt <<Best of luck in your venture, Matt. Tom>>

Piranhas, comp.  - 04/05/2006 Hi, My name is Brent and I have 3, 3inch Piranhas... my question is, is it possible to add young piranhas in the same tank as the more mature ones, or will the older piranhas eat the little ones. thanks Brent. <Most species of piranhas will bite, consume each other if hungry... All species need a good deal of room per specimen... twenty or more gallons. Bob Fenner>

FW chem., too lazy to search WWM... pH Trouble    3/29/06 Hi! I have a Red-Bellied Piranha in a 20-gallon aquarium. <How large is this animal?> Recently I have had trouble with the PH. It has been at extremely high levels  (like 7.6). I've tried to lower it by using Ph Down, but even after using it 3 times the PH has stayed the same. Any other suggestions on lowering PH? Thanks! <... such changes need to occur outside the system... gradually, with water changes. Please see here: http://wetwebmedia.com/FWSubWebIndex/fwph,alk.htm and the linked files above........ Bob Fenner>

Piranha cloudy eyes   2/6/06 Hi, <Hello>    I just setup a Piranha tank with three to start off. The tank has been setup for months with other fish, witched <"The house began to twitch..."> I removed to another tank. after acclimating to the new tank I noticed that two of them had cloudy eyes. They seem to be acting fine and all three are eating prawn. Could this be from the transporting them from the pet store to my home and the stress of it all? <Yes> any suggestions on what I can or should do, looks like they have a cataracts or something. The tank size is a 29 gal high, temp is 75 degrees with plenty if plants. I do have hood lights but I am using a top floating plant to defuse some of the light. Best regards. William <Mmm, what is the water quality here? I suspect this is where you're off. Simply fixing pH, alkalinity, raising temp. will likely "do it" here. See WWM re serrasalmines. Bob Fenner>

Piranha system, compatibility question    1/19/06 I had 2 red bellies in the same 55gal for about 4 years, I bought the 2 at the same time as small fish, and they grew up to be about 8-9in in length. I had to leave town for an emergency and when I returned home, one was beaten up pretty bad. <Happens> I had been gone for 3 weeks, and they had not been fed while I was away. The hurt one wasn't able to recover. Now the survivor just sits in the corner of the tank, whereas before the 2 swam around all the time. Are there any tank mates I could introduce into the tank? <Not likely... though if this tank were much larger, I might try adding the larger one to it... with a physical barrier (like louver) separating it from the rest/others... for a few weeks. In such a small system as the one is currently in, it is almost assuredly going to attack anything that "invades its space". Bob Fenner>

Piranha help... basic aquariums 101  - 01/12/2006 Hi there    <Greetings>   I recently purchased a new 65 gallon tank, set it up for a few days and finally purchased 4 new red belly piranha's. <Uhh... hold on a minuto... was this system cycled?> The first day they were fairly active but as the days went on the slowed down and would only float at the top and have no power. <Classic... "new tank syndrome"...> During this time they also developed white spots over their eyes. Finally, all 4 eventually died and I replaced them with 3 more. <Uhh, another moment please... peek-a-boo> This time all 3 looked to be fine until about 4 days into getting them when 2 died and one is now very slow again and developing the white eye thing. Can you please help me figure out what is wrong and what I should do before buying more piranha's?   Thank you   Colin <Time to go back.... way back... Please start reading here: http://www.wetwebmedia.com/FWSubWebIndex/fwset-up.htm then on to the linked files (in blue, generally above...) where you lead yourself. Bob Fenner>

Getting Piranhas  - 01/03/2006 I have a 30 gallon tank, all set up.. I will be ordering red bellied piranhas at 1 inch in length, I know they do better in shoals, but how many (at this size) would be best to put in the tank? I want an active tank, and as they grow, their tank size will also become larger. Also.. should I buy them at 2 inches instead of 1 inch, to insure stronger fish? thanks a lot-Matthew p.s. where can I make a donation to your site? It has been super helpful!! <Piranhas do better in groups. Alone they hide and really don't display much. I would get the one inch fish because this will give you more time to get the bigger tank. I have seen these fish up to a foot long. At this size they are less active. Six to these guys in a 75 to 100 tank would be fine with proper filtration and water changes.-Chuck>

Piranha injury  12/14/05 Hi! I have a 5'' red-bellied piranha that has a swollen chin. It has large bumps on it's chin as well. I think it is because it has been running into the glass often, <This often happens... Piranhas are quite "skittish" species... particularly if housed alone (most are schooling fishes) and rub their faces, run into tanks...> but I'm not sure. I'm wondering if there is anything that I need to do to treat it, and if I can prevent it from happening again. <Most treatments I'd avoid... more risk than they're worth in this case> I was thinking about putting more plants in the aquarium to help it feel more secure so it won't bump into  the glass all the time, but am still not sure that it isn't some kind of disease. Thanks for your help! <The plants are a very good idea (do watch your hands if/when in this tank... Bob Fenner>

Piranhas With Oscars  12/9/05 Hi Wet Web. I have a question relating to what will happen if I introduce piranhas into my tank. I currently have too palm-sized (about 7") tiger Oscars in my tank and am thinking of introducing maybe 1 or 2 piranhas to the mix. I am curious as to what will happen between them and whether one will dominate the other or whether they are both strong enough and aggressive enough species to get along with one another. Thanks for your time. Pete < Piranhas are much more confident in groups. As a single fish or even a pair I think the Oscars would push them around. Much depends on the species of piranha and the sizes of all the fish concerned. In the wild piranhas pick on Oscars all the time. Wild Oscars have developed a black spot near the tail to look like an eye to the piranhas so they won't be able to tell which end the mouth is at.-Chuck> <<RMF strongly believes the Oscars will end up with chunks missing>>

Piranha Illness  10/2/05 Hi! I have a Red-Bellied Piranha that I have had for 5 years. He has done well up to this point. Just recently, I've noticed that he has been swimming on his side and upside-down. I was afraid that he might have something like gill flukes. I'd hate to have him die if I can do something about it. Thanks! <Mmm, not gill flukes or any pathogenic/biological cause unless you've introduced the vector through feeding contaminated food/s. More likely environmental... I would (very quickly) check your water quality and whatever it shows, start large daily water changes (like 30%) with water that this fish lives in (soft, acidic, low nutrient load, warm). Bob Fenner>

Piranha Shedding? 7/27/05 I have 5 red bellied piranhas in a 55 gallon tank <A wee bit overstocked there, are we?> and they were all doing very well until about two days ago when one of my piranhas got big dark spots near his head and looks like he is shedding his skin is this a bad thing. <Quite possibly so. Sad to say, I have absolutely no idea what it is. However, as you know exactly what it looks like and have an image (your fish) for reference, it should be decently simple to locate the disease and accompanying treatment info within the following links: http://www.wetwebmedia.com/tanktroubleshting.htm http://www.wetwebmedia.com/tanktrb2of2.htm http://www.wetwebmedia.com/FWSubWebIndex/fwdis3setsfactors.htm http://www.wetwebmedia.com/FWSubWebIndex/fwfshparasites.htm http://www.wetwebmedia.com/FWSubWebIndex/fwinfectdisfaqs.htm http://www.wetwebmedia.com/FWSubWebIndex/fwfshparasitefaqs.htm http://www.wetwebmedia.com/FWSubWebIndex/fwinfectdisfaq2.htm Good luck, and I hope he pulls through!> thank you Anthony <Mike G>

Red Belly Piranha 7/11/05 I have 2 red bellies in my tank at home aside from feeder fish I want to offer them some fruit alternatives. What type of fruits or greens do you suggest? They have lived off of feeders and lean lunch meat for 6 years but I would like other alternatives... Thanks! Chris M <Other lean, meaty foods... like earthworms, mealworms, crickets, fish fillets... I doubt that they'll accept plant material, but you could try blanched/microwaved bits of squash... Bob Fenner>

I'm getting some Red belly piranha's  07/02/05 Is it ok if I only get two or should I get more? And is it cheaper to buy everything together or separately? If you can please help me.               Thank you for your time,                      Jodi Sue Strong <More are better, social animals... if you have the room, mechanicals for them (filtration, aeration, circulation)... a good twenty to thirty gallons minimum per individual. Likely it is less expensive to acquire more gear, livestock at once. Bob Fenner>

Piranhas 'still illegal in California  12/9/05 Hi <Hello.> Just wanted to know if you know anybody selling the piranha I'm trying to locate but still having a hard time to find one. I live here in California. <Ahh'¦bingo, all species of piranha are illegal in our Golden State here'¦both to sell and own. But on the bright side you can't beat the weather here. I'm enjoying this 65 degree winter.> and really wanted to get the red. Pls send any info at XXXX@X.XXX <Sorry I could not be of more help, Adam J.>  <<Be smart, go with Pacu.  They look a lot like piranha, are nowhere nearly as difficult to keep, and are fun to feed big bugs to.  Marina>>

Piranha Questions Sorry to bother you again, but you've been most helpful. . . The room that my tank is set up in unfortunately had plumbing problems in the ceiling from the bathroom above and was exposed to mold. . . about a week later I noticed similar growth in the tank and have since lost three of my five previously healthy baby piranha- what appeared to be a very rapid fungus growth on the fins/eyes. They died during treatment. <Mmm, highly unlikely that this is related to the room mold problem> The two left are about 1" and seemingly very healthy. I have since transferred them (temporarily) to a community tank w/ similar water conditions- minus the growth. They're actually more social in this MUCH smaller tank and are accepting more types of food as well. . . although a couple fish belonging to this tank have already fallen victim to some nasty fin bites! At this size the piranha seem to have similar mannerisms to their tetra relatives, although their relatives are about 2x the size! <Yes> I'm thinking about leaving them in the community tank for a while longer to get them accepting other foods and to be sure they're healthy before returning them to their larger tank. Is this ok if everybody seems to socialize well for now? There are tetras and some aggressive Gouramis (male/female) in there now w/ them (a Rose Barb too, but I think he'll be gone shortly because they've been picking on him. . .) everybody else is fine. <Mmm, well... you'll likely lose some livestock...> Eventually I will have to transfer them back to the proper size tank since they're growing- I've treated the room and have done my best at restoring the tank (changed water/vacuumed/treated w/ Melafix/increased flow & aeration) is there anything else I can do?  <I would leave off with the "Fix" material. More trouble than it's potentially worth> It's been two days so far since they've been out and I've cleaned up the tank- how long should I wait before returning them? <A couple weeks.> I would also like to add another 3 fish once I know the tank and current fish are healthy, and I'm assuming this is best done while they're this small (??) <Yes> I want to keep a healthy shoal of 5- I've already owned a single piranha in the past and want to see the difference. . . THANKS, Aja <Much more natural behavior, interesting social interaction in a group... How big is this tank? You need at least 25 gallons per individual... Bob Fenner>  

Re: Piranha Questions Well "their" tank is 30 gallons for now. They're 1" at the moment. <For five piranha of this size... dangerous. Do keep them well fed...> I have a 50 gallon designated for them once they're a bit bigger and will be investing in a large enough aquarium for them when the time comes to move from the 50 (I'm assuming that'll be sometime next year?) <Perhaps sooner...> I'm sure I'll lose some fish while I'm waiting for the tank to clear up and be safe. . .is there anything else I can do to be sure this won't happen again? <Redundant filtration, circulation...> The water conditions were not great (hard, and low pH) but everything else Ammonia and Nitrates, etc. was at 0. What do you think would've caused this?  They were perfectly healthy for a week and rapidly deteriorated over the course of two days. I know they're fragile at this size, but. . . Thanks, Aja <Perhaps some unknown change in water quality, maybe something "got into" the system... an aerosol, cooking oil cover on the water, window cleaner... Bob Fenner>

Recurring Piranha Fungus... something/s missing in set-up, care Good morning, <And to you> We have a 30 gallon tank with rocks, a filter, a heater, and a red belly piranha. We originally had two fish, but a nasty bout of fungus killed one of them. <Unusual... if your water is suitable at all... mid to low pH, not too hard, heated, cycled, filtered... Piranhas are by and large tough, disease-resistant> Since then, the survivor fish (Ali) is on his third bout of fungus in two years. I keep Maracyn-Two and Maroxy at home. Two days ago, Ali's had a patch on his eye and a tuft of fungus near his fin. The fish store once told me that adding some marine salt helps so I added one tablespoon two days in a row. Yesterday he was really slowing down, so I medicated with Maracyn-Two, because his symptoms most resembled the description on that box. This morning he has fin rot, which seems more like the Maroxy symptoms. Which medicine should I use? <Ideally none> Can I switch now that I started with the Maracyn? How can I help prevent this? <Let's review your system... Have you read the piranha article, FAQs posted on WWM?> The fish store suggested that feeding him live fish might be causing it <Yes> so we feed him defrosted silversides and try to clean up anything he doesn't eat. Is there anything you can do in a fresh water tank kind of like adding live rock to a salt water tank? We try to change a couple of gallons of water every two weeks or so. Thanks for your help, Vanessa and Frank <In this size tank... you should have redundant circulation and filtration... Do you monitor aspects of water quality? Much not stated in your mail here... Do see WWM and write back if you have further questions. Bob Fenner>

Piranha/Biological Filtration I read through the Piranha FAQ the other day and found it very informative. I've kept fish since I was very young and have had good "luck" with them. . . I say luck because I've never done anything special- they've pretty much just stayed alive for me w/ minimal maintenance, supervision, cleaning, feeding, or much care at all, really. . . <Good> Well, I currently have a 9" Oscar in a 50Gal, three 3.5" Jewel Cichlids in a 30Gal, and some small tetras in a 5 gal. . . I'm also cycling (for the first time, LOL!) a tank to be ready for some baby Red Belly Piranha. Their beginner tank is 30 gal for five 1.5" Fish and I plan to move them up to a 50, and eventually 100, gallon tank. I've had a Red Belly before (10", solitary fish, died at 10 years old) and am quite familiar with the mannerisms of the fish- at least as a single fish. . . and I'm really looking forward to my new crew! I would like very much to care better for these fish so that they're healthy and grow large. <Sounds good> I've been reading up on balancing the fish's diet, etc. . . and think I'm ready to handle that aspect- my old Piranha ate live feeders only and would go through about 6 large feeders in a week period and fast for three weeks. . . poor fish! I do have some question as to the filtration of the aquarium, however. Since I am new to the concept of a biological filter- although have obviously always had usually more than one per aquarium- I just wanted to verify that I have the right ideas in mind. I'm pretty sure that I've only had luck w/ water quality simply because of my little maintenance or feeding in combination w/ enough space for the fish involved- I never killed off the bacteria or created poor water conditions w/ too much waste (??. . .that's the only explanation I have. . .) <A likely one> SO, to keep my new fish healthy, I have set up in my 30 gal 2 biological filters, each designed for a 20 gallon tank. That's all I have available now and I figured that I can alternate and clean one per month in siphoned tank water. . .will this work? <Should> Do they have to be cleaned, it's just to get debris/waste out, right? <For the most part, yes> Thanks for your help. . .I'm very exited about my new additions! Aja Harris <I encourage you to institute regular water change-outs, gravel-vacuuming... with pre-mixed, stored water... and to add some circulation to the system. Bob Fenner>

Re: Piranha/Biological Filtration Thanks. I do have the tank set up w/ some places to hide, as well as an airstone and a powerhead for circulation and extra oxygen in the water. I added the fish last night- they seem to be doing well so far! <Ah, good> Question about vacuuming the gravel - am I supposed to press the vacuum down into the gravel, or just skim the surface of it? I've always pressed it into the gravel in the past, but am wondering now if that will negatively effect the biological system (??) <Vacuum half at a time... see WWM re...> Also, what are some tips on softening the water and stabilizing the Ph? <Also posted on... WWM> I know they're related. . . I have very hard water (live in Baltimore, MD) and I know that's bad for the fish- it seems to be constantly lowering my Ph as well. I know Piranha like a lower Ph, but I can't keep it above 6.0 for long at all. . . <Actually below...> AND it seems that no matter what I do all of my tanks end up w/the same water chemistry in the end- my Cichlid tanks, my small tetra tank, and now my Piranha tank as well. Hard water (400+), low alkalinity (0), and low Ph (6.0) My ammonia and nitrate levels are at (0) in all as well- at least that's good. . . Thanks! Aja <I'd be investigating and investing in an R.O. device... Bob Fenner> 

Piranhas filtration Hi, I have a 100 gallon tank and 5 red bellied piranhas. I was wondering if a lot plants would give enough oxygen to the piranhas with no top water disturbances. and are there any filters you recommend for the 5 piranhas and 100 gallon tank ( internal and isn't noisy). See I have the piranhas in my room and I cant sleep with loud water disturbances or noisy filters. I wanted to put a lot of plants and an submerged filter. I was wondering the best filter I could use that can be completely submerged and no water disturbances. or are there any other oxygenizing methods I could use? <For this size system, this number of fishes, likely wastes... I would use two good-sized (large) power hang-on the back filters... and if possible, direct their discharges (some you can, some you can't) to move the water in the tank in a large "swirl" or vortex... if not direct-able, I would add a couple of large powerheads (I like the Tunzes, but they're expensive... maybe Hagen or Aquarium Systems lines) in both upper, back corners to generate the same sort of water flow... Only clean one of the filters per week to preserve biological filtration... along with water changes... Bob Fenner>

Tankmates for Piranhas Hi, I'm thinking of getting a 100 gallon tank and about 4-5 piranhas (red bellied). I was just wondering if algae growth is a problem and could I add a Pleco to the group to clean things up? Or can I get a filter that is strong enough to get rid of all the algae and keep things clean? One more question. Can I keep plants with piranhas? Or will they destroy them? And if any plants are toxic to piranhas. Because I wanted to make a tank with plants to cover some of the light because piranhas hate bright light and can't stand it. Thanks, your web site is very useful! <A big Common Pleco "may" be able to live in this tank. Give him a cave to hide in during the day. But in the close confines of even a large tank anything can happen. They are poor algae eaters as adults anyway. So I wouldn't stock one. You're going to need tons of filtration and an algae scraper I think. I suggest a scraper that will not require you to reach in the tank. Floating plants should be OK. Don>

Piranha Systems Hi, I have recently bought some piranhas, they are all about 2-4 cm and I think they are red-bellies (they are silver with black spots and red bottom fins). <Likely this species or Pygocentrus piraya> I read questions on your site and just wanted to know if my conditions are ok and what to do to improve the health of my fish (having read the lack of understanding many people have of them I am keen to get it right and be able to take full care of my fish). For a start I have a 62 litre tank (is that about 16 gallons?) with 6 piranha of the size I said. <Yikes... this is a way too small volume for this number of fish... even when small you will find them chewing each other up substantially... eventually killing all but one... This number of piranha really should ultimately be kept in a system about ten times this size> I'm feeding them frozen bloodworm and brine shrimp, lately I have been feeding them more than the shop owner's recommended half a cube a day because they bite each others' fins.  I have lots of real and fake plants in the tank, as well as some fake tree roots ( I read they like lots of cover)... <Yes> ...and a skeleton that bubbles. I have a heater at 77*F and filter (I say simply filter because I don't quite understand biological and mechanical filter and all that)... <Oh, simple to grasp...> ...it is one that sits in the tank and pumps the water with sponges in the middle, in that I have nitrite removers and a bag for algae removal. I use Nutrafin cycle and Plus to keep the water hardness and stuff right, I also have ph balance to keep it at 7.0. You should also know that I have two Plecos (catfish) in the tank that eat algae and mind their own business, the bigger piranha sometimes try and bite them but they have tough skin and are at least 5cm so the piranha leave them alone. I would GREATLY appreciate any advice or any change that you would suggest. thanks <Principally larger quarters... do plan on moving these fishes to a bigger tank... SOON... and I would add another outside power filter (either hang-on or canister)... for added filtration and circulation... These are gorgeous fish, and you can look forward to enjoying them for many years with good care. Bob Fenner>

Re: piranhas Hello, thank you for your guidance!, I will increase my tank size very soon. could you help me with one last thing please. I want to start feeding the fish some meats to bring out their natural hunting instincts etc.. but I read its not good to feed the fish meat like beef heart but instead raw prawns and salmon. <Actually, some beef heart is not a problem... I had piranhas of a few species for several years and fed this along with other meaty foods> I saw some raw prawns at my local supermarket, are these ok? <Yes> because I know food for human consumption is packed with preservatives and chemicals (and crap). If not where would be the best place to get theses foods? thanks again. <Bait shops, earthworms from your yard/garden, growing mealworms (actually beetle larvae), oriental grocery stores... Bob Fenner>

Piranha Question Hi, my name is Jeff.  I have had a red belly piranha for 3 1/2 years in a 29 gallon tank.  I am guessing it is  about 6 or 7 inches long.   <Mmm, needs larger quarters> For some reason, I have not been able to get it  to eat in about 3 WEEKS.  When I have had problems with it not eating in  the past, it would usually have visible symptoms of some type of illness, such  as swimming towards the top of the tank, heavy breathing, cloudy eyes, or other  types of uncharacteristic behavior. <Most likely all directly or indirectly to being in too small a volume> This time, however, it seems totally  healthy, besides the fact that it will not eat.  It still seems to have as  much energy as it normally did and does not appear sick or  malnutritioned.  It has been on a diet of a variety of foods, such as  Formula 1, frozen clams, beef heart, and a few other different frozen foods to  incorporate a variety in its diet. <Ah, good>   I have tried each one of these foods at  least once in the past few weeks and only one time did the piranha take a few  bites of the Formula 1.  Normally at feeding time, as soon as I open the  hood of the tank, the piranha darts around because it knows that it's feeding  time.  Now, it shows absolutely no interest in the food and the food will  just sit for a few minutes until I remove it.     I did a 10 gallon water change on Saturday, January  8.  I made sure the water that I was putting into the tank was the same  temperature as the water already in the tank (74 deg. far.), and that it was  dechlorinated. <Mmm, though Piranha do go through lack of feeding bouts, I would definitely raise the temperature here... to the low eighties F. over a period of a few days> It was the same bucket I normally use for cleaning my  tank and it was kept away from anything that could have gotten into  it. <Good> I also changed both filters in my tank including the biological  one. <Mmm, I would NOT change all filtration at any given time... too likely to interrupt biological cycling> On Thursday, January 13, I tested my water. The pH level was  about 7.0, and there were no traces of ammonia.  The nitrite level was  somewhat high at almost .50. <You no doubt are aware that the nitrite you want to be non-detectable... i.e. 0.0 ppm>   The nitrate level was at about 40. On  Sunday, January 16, I did a 5 gallon water change, using the same procedures  mentioned above.     So my question remains. . .what do I do now?   Should I use medicine? <Raise temperature> Is the piranha too big for the 29 gallon  tank? <Yes> Is the piranha's time about to be up? <Doubtful... have been known to live for decades> If you could help  me with this problem I would greatly appreciate it. Thank you in advance,   Jeff <Try raising the temperature, continue to offer food as you have been doing so well... and do look into a larger tank, some added filtration, circulation for your Piranha. Bob Fenner>

Re: Piranha Question Mr. Fenner, <Jeff> First off, I would like to thank you for your response to my questions concerning my piranha. As you suggested, I gradually raised the temperature to about 83/84 degrees far. I have continued to try feeding the piranha different foods (except live food) and it STILL will not eat!  <Mmm> Unfortunately, I am not able to look into a larger tank for it at this time, for I do not have the space nor the money to do so. I can only hope the tank size is not the difference between life and death for it now. <Me too> As far as added filtration, I already have a Whisper filter and a Penguin Bio-Wheel filter in the tank. What else would I get and will it even fit in my 29 gallon tank? <Perhaps another hang-on power filter or a canister type> I have not tried adding circulation either. What do you suggest? <A powerhead or two... in the upper back corners...> I have also tested the water again and it actually looks even better than before, with much lower nitrite levels. <Should be zero... this DOES negatively affect your fish's health, appetite> As far as the piranha's behavior, it usually just stays in one spot for the most part. However, it has been showing some peculiar behavior where it freaks out and darts across the tank, banging the heater, filters, and gravel.  <Quite common for solitary piranha species in small tanks... they're much more calm in a group, in large systems> Physically though, it still looks healthy, with the exception of some wounds from banging into the different objects I mentioned. So, what do you recommend I do now? Should I try some sort of medication?  I'm beginning to get worried.  Thank you in advance, Jeff Harris <Wait... your fish will NOT starve... for the nitrite to go to zero... then offer an assortment of meaty foods... a bit at a time. Bob Fenner>

Feeding Piranhas Do you know of any ways to get my piranhas to eat anything but feeders that would be great.  I've tried mixing live with salmon chunks, krill they eat sometimes, but usually they refuse and then the fin nipping and body wounds begin.  Starving is out of the question as one has just recovered from an eye injury caused buy the other during my attempt to starve them so they would eat something else.  They are about 4 and 4.5-5 inches long right now and GROWING!  Thanks! <Is perhaps the major drawback of piranhas... think your plan to quarantine feeders may be your best bet, that and continue trying to mix in other foods from time to time. Cheers, J -- >

Possible Piranha Partners Hi! I have a 2 inch long piranha in a 10 gallon aquarium and was thinking about moving into a larger aquarium and possibly adding 1 or more piranhas his size. Do you think I could do that without the piranha nipping or killing the other piranhas? <Lot of different species of Piranha out there. I'm going to assume we have a Red Bellied. Colorful, mean and (too) commonly sold. Well fed Piranha [I] usually[/I] will not kill one another. In the wild they do travel in schools. In the confines of an aquarium the danger levels increase. If you are looking to produce a large display quality fish I would recommend you keep him alone. If nipped fins, missing scales (or worse) does not bother you then get a couple more of the same species. I would either keep one or a school of 5 or 6. This will spread out the damage if one or more are on the aggressive side. But if you want a school, you will need a MUCH bigger tank. 150 gallons or more with great filtration. Your single would do well in a 55 for many years. You could get away with a 29 for awhile, but you will have to upgrade in time anyway. Red Bellied Piranha get huge. Dinner plate to serving platter sizes are possible. One more point. Please do not offer them feeder fish. You WILL, not may, introduce Ick or worse into your tank. Train them to take human seafood, worms, insects. Stay away from land animal meats. Any freshwater seafood, including feeders, should be frozen for a few days to kill off bacteria and parasites. Good luck. Don>  

Piranha Hi guys, thanks for any help you can give me! <You're welcome> I have just bought 4 juvenile Piranha (Pygocentrus nattereri ) and housed them all in my 75 (US) gallon tank. They are very young and are only around my fingernail in size, apart from one. He is at least twice the size of the rest and far more active and a stronger swimmer. I am a bit lost on how to feed them; the local fish stores keeper said they would eat flakes for now. <What? No... or at least not substantially... try feeding a lion or a tiger naught but "Cornflakes"... if you get my drift. These fish need animal protein, and likely live at first... like NOW... as they will definitely bite, even eat each other...> With the fish being so tiny and the tank a fair size it seems impossible to feed them without making serious mess and waste. Will they feed from the bottom? <Yes... if the food is live, moving... you might try a trick with a glass (so you can see what's going on) and black worms, Tubificid worms... Or juvenile livebearers (baby guppies, platies...)... occasionally live brine shrimp, daphnia, glass "worms"...> Some form of tablet that can easily be removed if not touched? Flakes get everywhere and I think the sand substrate will be far harder to clean than the usual gravel in my community tanks. I only really wanted 3 in the tank with it being a little small for the intended fish but I thought there maybe a risk of one dying through cannibalism! <You are wise here> I have a spare 10 gallon tank that is not in use; do you think I should house the biggest Nat in that till the others catch up in size? <A good plan... in fact, it might be advisable to place all them in this smaller volume to facilitate feeding them, making sure they're all eating... for a few months> Or will this lead to other problems when re-introduced with his equal size tank mates. He is a loner compared to the others, they tend to shoal together nearer the bottom. He tends to swim around on his own nearer the top, it is 2 ft deep. I suppose the current is a little strong for them too. A powerhead (AquaClear 30) is in there but not switched on because the Eheim 2026 Pro II current seems a bit strong for them anyway. Cheers, Ian <This is not too strong a current... and a good way to make sure they are getting exercise, oxygen, and loose material is being stirred up for filtration removal. Do look on the Net under the words "Piranha, feeding, aquarium". Bob Fenner> Re: Piranha I am feeding them frozen cubes of Brine Shrimp and Bloodworm, I mean they are eating flakes too. The Lions and the cornflakes made me laugh, a good comparison! Do you think I should give them live foods then? <As long as they appear "full" and are not picking (bites missing out of fins...) all should be fine> I didn't really want to feed them live fish, I hate killing things! But bloodworms and Brine Shrimp I would. Are they too small for cut up fish fillets? <Not if they can be slowly trained onto same... try mixing in bits with the foods they are presently consuming...> I didn't really understand the glass trick bit? Surely If I put them all in a 10 gallon tank I am almost certainly going to lose a few to cannibalistic tendencies? <I would skip on moving them if they're all eating what you're offering. There is indeed more chance of cannibalism if they are more crowded> The larger one does tend to chase the smaller ones around. I was thinking about putting a shoal of Neon Tetra in there because I would like some of these in my community tank. They could grow out a bit in the larger tank. Would the Piranha, if they must, be more likely eat the Neons than each other. <Yes> I don't really want to see any fish die but I would rather it be a little Neon than one of my Nats. Thanks once again for being most helpful, Ian <Glad to share with you Ian. Bob Fenner>

Fruit-eating Piranha ID request hallo! my name is Francesca and I'm Italian. I'm sorry for my bad English, I'll try to do my best. I saw you email address on the page http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm and I thought you know a lot about piranhas. I have just bought a piranha but I can't find (or I'm not able to recognize) what type of piranha is. a friend of mine told me it is vegetarian. I hope it is not so. anyway, if I'll send you a photograph of my baby, could you give me some information about it? I don't trust in the man who sold me the fish. thank you very much Fra <I only know a little about piranhas, but we have a few good friends here that will gladly look at your photos and help in identifying your fish. Ciao Bella, Bob Fenner>

Red belly piranha I have a red belly piranha. I have had him for about 3 weeks he is about 3 1/2 -  4 inches. I came home and he was sitting sideways looking at the top of the tank like he was dead but when I touched the plant he was moving again what is the problem  <Hi there. Red Belly Piranha are pretty messy fish, and they quickly foul water unless you give them a large tank with plenty of filtration. They are used to living in a river system with constant fresh water flowing. I would test the water levels and make sure that the ammonia and nitrite levels are okay. Then add powerhead to increase current, also airstone and air pump to add the needed oxygen. I also suggest you check out websites like www.piranhafury.com, there are many piranha owners there that can help you enjoy your pointy toothed little fish. good luck. -Magnus>

Piranha Problems I have had a 29 gallon tank with 2 red belly piranhas in it for about 2 and a half years now.  There are 2 filters, one just the regular whisper filter and the other is a biological filter. One piranha is much bigger than the other one and always has been because it gets to more of the food before the smaller one.  About 2 weeks ago, I noticed the smaller one looked very malnutritioned and it would not eat.   <It does sound like he was outcompeted for food.> My piranhas have been on a regular diet of beef heart for the most part since I have had them.   <Beef heart is not an ideal food for any aquarium fish.  The highly saturated fats in this and other mammal and poultry meats are indigestible by fish and will accumulate in the liver, possibly causing serious health concerns down the road.  Please consider using fish meats, like fresh salmon or trout (preferably boneless!), cut it into manageable pieces and freeze before feeding it to them.  You could use prawns, cocktail shrimp, prepared meaty fish foods (I like Ocean Nutrition's "Formula 1"), or prepare your own frozen blend of such foods.  Here's a link to a basic plan of how to make your own foods (the article is reef-oriented, but will serve well to steer you in the right direction in feeding any tank, just adjust to that tank's needs):  http://www.ozreef.org/diy/reef_food.html .> The small piranha was unresponsive when I would put my hand near the tank, and that would normally make it swim away.  He had no physical signs of sickness other than looking very thin. I did around a 40% water change about 10 days ago.  The water change did not help and to get straight to the point, the small piranha died tonight.   <It could very well have been that he was outcompeted for food by the other piranha, and simply starved, or it could have been internal parasites, reaction to water conditions, etc.  Too many variables to tell for certain.> Now throughout this entire time, my bigger piranha has seemed very healthy and has been eating consistently.  However, when I found the small piranha dead, I noticed that the bigger one was acting a bit lethargic.   <Ooh, not good to hear....> I just did a 50% water change, and my water is fine, <That's rather vague, can you tell us specific water parameters, especially ammonia, nitrite, nitrate, and pH?> but I am very worried because my only piranha is darting back and forth, and swimming to the top of the tank.  He seems to be breathing fast too.   <Yikes, this sounds like a reaction to something in the water - did you dechlorinate the new water?  Did you match temperature and pH?  Again, water parameters will help determine what is going on.> The only other option that I know of is to medicate the tank with Oxytetracycline.  Should I use it?   <I would not, not without knowing what you need to treat for, if anything.  Again, it sounds more like shock from something in the water from the water change.  My first guess would be chlorine poisoning, which is why I ask if you dechlorinated - and are you sure you used the right amount, if you did?  When you refilled the tank, is it possible you used a receptacle that had held any household cleaners?  Have any possibly toxic foreign objects made their way into the tank?  Is all equipment functioning properly?> What should I do next?   <If you did not dechlorinate the water, I would do another major water change, replace with dechlorinated water of the same temperature and pH.  If you *did* dechlorinate, then we'll be back at the drawing board, hopefully after you let us know your water parameters.  It does clearly sound like he's irritated from something in the water.> I could definitely use your advice because I don't want to lose my last piranha.  Thank you very much in advance.  ~Jeff~ <I do hope we can help you out, Jeff.  Please get back to us, and keep us updated.  Wishing you well,  -Sabrina>

Piranha tail injury I purchased 2 gold (Spilo) piranhas from a fish store. <This is Serrasalmus spilopleura, yes?  I'm used to these being called red-bellied piranha, so I don't know if we're thinking of the same fish> I did a little research on them, but after I got them I did some more and realized it was a bad  idea having two in the same tank. Sure enough, after about 3 weeks in my 55 gallon the meaner of the 2 (always charging the tank when I came around where as the other would hide) bit my other one in half. <Yeowch!  What a way to go!  I guess I need not say that it's always better to do all your research before getting the fish....> When I first purchased him, he was in a tank with about 30 others so fins and stuff were bit off. I've had him for about two months now (he's about 3 inches) all the fins grew back except for the bottom half of his tail. It looks like it was bit off at the end of his back bone, and I wanted to know if the bone just takes longer to heal than fins or will it never grow back? <Well, since the damage was so extensive, and it's had ample time to heal, it may simply be that way the rest of his life.  Give it some more time, though, and just keep an eye on it.  Consider it a battle trophy, not a flaw ;) > Since he's now in a tank all by himself except for a Pleco he doesn't bother with, <Lucky Plec!  Though seriously, the Pleco's probably perfectly safe, as long as the piranha's fed - as you've already observed him to be.> I want him to be 100%. Also I was wondering how large my piranha will get in my 55 gallon. <Well, FishBase.com says S. spilopleura gets up to 21cm (about 8.5 inches), and I daresay I've never seen this species grow larger than that, so he'll probably be fine in the 55, if he and the Plec are the only inhabitants. Please write back. Thank you <You're welcome. -Sabrina> Ken R.     

Piranha with gill curl I know Arowanas get this. I have bought a rare piranha. (Pygocentrus piraya) And it has gill curl. I know it is not from me. The fish was 2 inches in size when I gotten him, So I did not notice the gill curl in time. It is pretty advanced now being that 1/3rd of the hard part is affected. What surgical procedure do you recommend? If I cut all of it off it will show a good deal of his gills. Or do I make relief cuts in the gill toward the head? Or a little of both? <Actually, neither of these. I would leave this animal as is. "Gill curling" is almost always either a manifestation of genetic disposition or a developmental anomaly. The last due to "poor water conditions", lack of dissolved oxygen, nutritional deficiency... Not "correctable", and likely more dangerous to cut the existing structure in hopes that it will regenerate "properly" than the possibility of damaging, killing the specimen> As him being a piranha. A feisty one at that. What tranqs are easy for a hobbyist to obtain? <tranqs?> I have never done any surgery. So if you could give me a step by step instructions that would be great. Thank you very much. <Bob Fenner who would "live" with the curled gill cover.>

Crowded Piranhas When baby piranha starting getting bigger and older; I have the tank well planted and plenty of hiding spots for the fish. Now the Piranha are developing the Red characteristics, should I remove these hiding spots? The rock takes up a lot of room and it used to house 4 piranhas, now it could probably do 1 or 2; I am worried about the fish fighting with each other, what should I do? <<I don't know the size of your tank but I'm guessing it's fairly small. The safest course of action would be to get down to 1 or *maybe* 2 fish. Ronni>>

Urban Myth In The Making! (Krikey, there's a toothy tetra in me loo!) A friend of mine is having trouble with her septic system. she was told if she gets a piranha and put it in her system it will clean it out I have never heard of it. <Umm- no offense to your friend- but this is one of the kookiest schemes I've ever heard of! First off- a septic system is no place for any living creature to reside in! Second- Releasing any non-native species into a domestic water source is both immoral and definitely illegal! Last, but certainly not the least- why in the world would she even think of using a piranha, of all fish, in such a capacity? I'm sure that the Yellow Pages in her area has a number of listings for septic system maintenance people, that do not use piranhas, divining rods, magic crystals, or psychic powers to do the job!> If there is any info on this could you send it to me. this is a real question- I would like some help. <This is a real answer- have your friend call a professional septic system maintenance service!> Thank you very much. deltadawn <You're a good friend for taking all of my abuse- but, seriously-do have her call a professional to solve her problem! Scott F.>

Piranhas (Note: Post URL on FW Subweb, Serrasalmines) I wouldn't mind writing something pertaining to the behavior of Red Belly's, Cariba, and Ternetzi. Those are the three species I have experience with those three Piranha species. I know of the best article I ever read on piranhas posted on a message board that I can ask the owner if he wouldn't mind sharing. <A good idea> If its possible to instead include a different web site:Aquatiqterrors.com instead because I am a member there and they are also very informative when dealing with: snakeheads, piranhas, cichlids, and catfish. <Will post on WWM> My friend has much experience with the very rare serra species such as; Elongatus, Branditi, Gold Spilo, Black Diamond Rhom, Medinai, etc... and probably wouldn't mind writing a small profile piece. <Very well. Will cc Jason.C here (our CA Online Magazine Editor) for his guidelines, input> www.aquatiqterrors.com <Bob Fenner>

Hi (Piranha info.) My friend gave me this link when I was doing research on saltwater setups and was browsing in the Piranha section, since I have had them for quite some time. There are two pygo species that are missing from the list and are compatible as well to the natt's and piraya. Ternetzi and Cariba. The piraya grow to over 18 inches in the wild, not 13. Also a few good tips would be that 1. Never keep two Pygocentrus together in a tank. One will kill the other over territory. Minimum keep either a single species like most of the Serra. family or 3 in the Pygo family. 2. Good rule is 20 gallons per pygo. 3. There are two sub-families, The pygo which can be interschooled and the serra (rhoms, spilos) which generally are solitary (except maybe gold spilos, dentics rarely). These are not to be schooled will kill each other. You can go to predatoryfish.net. They have the most knowledgeable people on piranhas on the internet by a long shot. <Great! Thank you for your valuable input. Will post on the site, as well as the link on the bibliog./further reading for the group. Have you thought of writing a short book, series of articles on the Piranha and relatives? We might be able to pay you for same, publish in our online zine and post on WWM for others ongoing use. Bob Fenner>

Piranhas in a 55gal. hello, I have a 55gal. tank and have two 2.5inch piranhas and want to add more. I was wandering how many I could add if any, and if I should take the two piranha I have now out and put them back in with the new ones. what do you think? john <I really like this group of fishes (a subfamily or family of what we generally call tetras or characiform fishes, the Serrasalminae or Serrasalmidae), but in order to give you more of a definite answer I need to know the species we're talking about. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm As you can see some Piranhas get quite large, and some species are much more difficult to keep together in such a small volume as yours... The time to add any is when they're small for sure, and all the same species, about the same size... Bob Fenner, who wishes these fishes weren't outlawed in California.>

Piranha I have a Red Belly Piranha, about 6 months old. I want to know what kind of fish can go with him. I had a Red Devil that was bigger than him in the tank. The tank is 20 gallons. <Sorry, but there is nothing else you can house in a 20 gallon tank with a Piranha.> The Red Devil went after the Piranha. The Piranha did not fight back when I saw them fight. One day I went to look at the tank the Red Devil was in half. I want to know what fish if any can live with him. Thank you, Mike <Have a nice night. -Steven Pro>

Enough Oxygen in Piranha Tank? I have a 120 gallon "high" tank (22-24" high and 5' long). I have 5 Piranhas in the tank and the water is set at 79 degrees. I use 2 AquaClear 500 filters and a Magnum 350 canister for continuous polishing. I also have a Hagen Powerhead (model 900 something) that turns about 400 gallons per hour. I use the power head for current only. I have the power head on a timer. It's on for 30 minutes, off for an hour, on for 30 minutes, off for an hour, etc. for each day. I know it's harder to get good oxygen in warm water <Correct, but 79 is not too hot, just about right.> just want to be sure my fish are getting enough oxygen. And how can you tell if you're not...do the fish become lethargic or something? <Yes, become lethargic, stay at surface gasping for air.> 2 of my Piranhas always stay about 1/2" from the top of the tank in the corner while the other 3 stay at the very bottom. Not sure if this is due to oxygen levels or not. Any ideas? Travis <Could be territorial disputes. Oxygen levels can be verified by test kits. Also, look at the other regular parameters; pH, ammonia, nitrite, & nitrate. -Steven Pro>

Misinformation on the piranhas Hey Robert You have mis information on the piranhas the species piraya get bigger then 13 inches. They can get around 20inches <Thank you for this input... hmm, have kept this species of Pygocentrus... didn't realize it attained such dimensions... according to fishbase.org this piranha only gets to 34 cm. standard length: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=8696& genusname=Pygocentrus&speciesname=piraya What leads you to believe (reference, personal experience...) that this fish grows to fifty centimeters? Bob Fenner>

Re: Mis information on the piranhas Hey Robert Because I have personal seen two that were 14 and 15 inches. <Will post your observation as such. Bob Fenner>

Re: Mis information on the piranhas Hey I hope you dint take offense to my email. <No. "What comes is acceptable". Bob Fenner>

Red (-Bellied) Piranha Hi there! I have 3 Red (-Bellied) Piranha, but they are all stressed. Every time I go near the tank, they all swim around and hit on the glasses. Even I feed them, I have to go away from the tank, otherwise they won't eat. why do they like that? Is there anything that I can recover them? Thank you <A few things would likely help here... providing more cover in the way of plants and driftwood... more circulation in conjunction with your filtration, and inclusion of some "dither fishes"... like other characiform fishes and South American catfishes... as well as time going by, the tank being in a more public thoroughfare area. Bob Fenner, who says, we placed our Piranha piece's images last week on the www.WetWebMedia.com site, and took a few more pix yesterday at the Steinhart Aquarium... now need to flesh out the text for article and more inclusion>

Piranha Do you know how to make their bellied more in red colour? Also, How can I keep them healthy and in good condition? Thank you <A few things will help here... frequent, partial water changes... keeping the water slightly acidic and as soft as you can... and feeding your piranha with foods rich in carotenoids... like shrimp and krill... Bob Fenner, who is visiting in Cabo San Lucas, but needs to get back and finish writing the Serrasalminae piece on www.WetWebMedia.com...>

Re: Red (-Bellied) Piranha Does minnow bring the red belly out more? (As a food? Not really... I would avoid feeding freshwater fishes alive... too much chance for parasite problems... Please read over the 'Feeding Feeders' section on the Marine Index (I know, Piranha's are fresh)... on the site www.WetWebMedia.com Bob Fenner)

Piranhas Hi my name is Katie...I have a couple of questions thank you by the way your website has already answered some of my questions! I have a 55 gal tank, if I got them a 100gal to 150 gal tank will they get bigger, I have a one female and she's big but all my males aren't very big at all I have 5 all together) >>A bigger tank is always better. You will have a hard time with water quality in a 55g. Do you know your ammonia, nitrite, and nitrate levels?<< My 2nd question is one will get eye cloud and then the rest will get it all they are eating right now is freshwater shrimp could that be a problem? >>Yes. You need to treat them with a broad-spectrum antibiotic. Again, what do your nitrates measure?<< I only have one filtration system in there could that also the problem should I add some more I've had them for almost a year now so that would make them almost 2yrs old and it's been the same filtration system... >>How often do you do partial water changes and clean the filter?<< They also get really pale during the day and night for about an hour there bellies are really red and then they get really dull. I just want to make sure I'm doing everything o.k. love them and wouldn't want anything to happen to them. well I appreciate it if you could reply to this when you guys have sometime. thanks Katie:) >>You are welcome. -Gwen<<

My Piranhas (Sung to the tune of "My Sharona!") <Hi Katie, I'm not the one that answered your previous email, but I'll assist you with your piranha problems.> I do treat them with an antibiotic but it seems like every time we do that there fine and then it comes back even worse and then it starts with two and then all of them... <Then this is a sign that the tank itself needs work, not just the fish.> my boyfriend checked the ammonia level the other day and it was fine we can't seem to maintain pH.. <I don't know the size of the tank you have the piranhas in but these are rather messy fish and need lots of tank space. Piranha have evolved from fin-nipping species of fish. Their ancestors were small little fish that actually survived by eating the fins of larger fish. And through evolution they evolved into the larger voracious Piranha breeds you see today. That means that these fish will nip at each other if not given enough room. And when fish are left in an environment when their tankmates nip at them their health quickly deteriorates leaving them vulnerable to many different types of parasites and sickness. Aside from needing a large space, the major concern with any piranha owner is that these fish need some of the best filtration that can be offered to them. I had raised friends piranha for a while, when they were away at college and during that time I realized that only the best filtration should be given these fish. I doubled the filtration of the tank to help with seemingly endless illnesses... I found that the increased water flow and cleaner water made a great deal of difference. As for that, I would also suggest you set up a quarantine tank if you don't already have one. When I fish becomes sick remove it from the display tank and move it to a separate tank. This removes the chances of the problems spreading to the other tankmates. Also a sick piranha is more likely to be picked at by others, which isn't fair to the sick fish.> also what does that mean when they float near the top or they float kinda sideways not completely only a little bit and it doesn't happen all the time. <When fish that don't normally float near the top are seen there, that typically is a sign that their isn't enough oxygen in the water for the fish. Oxygen levels are higher at the surface of the water where oxygen exchange happens. This is a sign that you are not offering the right environment for these fish. You will need to bump up the filtration on these fish, and offer powerheads, and airstones/pumps to help with surface agitation to help increase the oxygen exchange. I feel that the reason these fish are getting sick is that the water quality is not up to the standards it needs to be. I suggest you check out some of the piranha forums online and talk to the owners. You will no doubt learn a great deal of info from them. A few places to start out with is www.aquatiqterrors.com or www.piranhafury.com. Both of these forums offer knowledgeable crew members specializing in piranhas.> thanks again Katie:) <Good luck with the fish, and hope they do get better. -Magnus>

Bob... pics of wacky fishes Hey, Bob... I came across some neat fish today (brindle cod... handsome enough to not want to eat). Hmmm... can send pic if you care to see. Attached though... a Thai pig nose FW puffer (neat to me)... and (no joke) a piranha that should have been culled: two fully functioning mouths. Sigh... <Bizarre. I could eat twice as much! I sense a Hollyweird potboiler coming on! Bob F>

Piranha's I have noticed that your piranha spec sheet is off a little. You can look at other websites to get a better understanding. It says that p. piraya is a max of 13 inches. That is a common Redbelly that can reach that size. P piraya can reach 20 plus inches. I am not trying to boast or anything like that. I just thought that I could help a little with your info. Also the piranha that is listed as p piraya is a red belly. If you want I can give you a correct pic to use on your site. It is one of mine, and no copyright infringement to worry about. I have learned a lot from this site and would like to give a little back. Thanks Alex <Thank you for the input and kind offer. Do send the Natterer's pic and I'll post it with credit to you. Bob Fenner on FishBase: http://www.fishbase.org/Summary/SpeciesSummary.cfm?ID=8696&genusname=Pygocentrus&speciesname=piraya>

Piranha problem? Hey what's Up! I would appreciate it if you could write back to me as soon as possible just bought 8 piranha for my tank. They are all babies a little bit bigger than a quarter. Anyway I went away for two days and my heater went crazy, I came back and the water was at 90 degrees. I bought a new heater now. I did a water change, added new water and added plenty of stress coat. My fish look like they are back to normal! Two of my fish fins are really damaged they Dorsal fin, it looks like they have been stripped down or eaten. <Very likely have been chewed by the other Piranha... very common. Not the heater; many species (there are dozens) do live in water in the mid to upper 80's seasonally.> Could their fins be prepared? <Yes. They can/do regrow in time. Just need to keep the whole lot fed (a few times daily), provide enough hiding spaces (plants, driftwood...) and keep up your water quality> Their eyes look cloudy. If these two piranhas died could I add two new piranha similar size to my tank. <If the system is large enough. You need a good two hundred gallons plus for this many of the smaller size species of Piranha. Please see here: http://www.wetwebmedia.com/FWSubWebIndex/serrasalminae1.htm> I have had my piranha for two weeks. I know once the tank is established you cant added a new piranha but since they are young could I added them???? Thanks A lot Barry <I would definitely not add any more unless your system is as large as stated. Bob Fenner>

Piranhas and Pacu (Oh! MY) Robert: <Anthony Calfo in your service... Bob has superglued himself to a piece of coral...strike one on his first foray into coral propagation> Thought I would give you an update and ask you a few more questions, if you don't mind. It's been over 6 weeks since I've had the tank set up and the Piranhas are doing fine - despite the fact that I have yet to get the pH down to their ideal range: 6.5 - 7.0 The tank has reverse osmosis water in it so it's very soft (85 ppm) so I would think that the pH would adjust fairly easily, yet it won't go below 7.6!  <what is the total hardness of the water coming out of the R/O unit and has this number been confirmed with another brand of test kit?> It's a mystery to me why the pH won't budge.  <85ppm is soft...but not extremely soft assuming that the test kit is accurate and not reading a bit low (which could explain the resistance)> The tank has been up for a while now and according to what I've read, all established tanks will see a decrease in the pH levels as this is a natural process.  <agreed and inevitable for most> I've also read that the softer the water, the less buffering and therefore the easier it is to adjust pH levels.  <yes> Maybe 6 weeks isn't long enough and maybe 85 ppm is still too hard of water. Any ideas on what's going on? <you are correct on both counts...but don't be obsessed with the low pH and soft water unless you are trying to breed them. The other side of the coin is that very soft and very acidic water is VERY unstable and quite frankly dangerous with the slightest slip in husbandry (overfeeding, delayed water change, etc)> I'm going to be setting up an 125 gallon soon and will have a Pacu in that tank.  <the tank is still not big enough...quite frankly, I hope that you don't buy the fish. It's an inappropriate animal for most tanks growing to over two feet in length. Cruel to let it stunt and die prematurely (a few years old) as most do> My research indicates they like the pH levels even lower: 4.8 - 6.5! <too dangerous for captive aquariology unless you are research strict about maintenance> If I can't even get my 55 gallon to a neutral pH...how am I possibly going to get an 125 gallon to a pH level of 4.8 - 6.5 ??? <my friend, have you considered drinking alcohol? Relax, goombah. A pH around neutral is safe and reasonable for such hardy fish and will serve you well considering the waste load they produce and potential for disaster at low pH/unstable soft water. If you are willing to go to such great lengths for water quality... breed wild caught discus instead and at least make money for your pains...hehe. Kindly, Anthony> Travis  

Follow-up to Piranhas and Pacus Oh My! Anthony: <You got Steven pulling his shift answering some of the daily mail.> Thanks for your input...I appreciate it! Can you tell I'm just a tad on the obsessive compulsive side? he he I'm glad to hear that I don't need to be so worried about the pH levels and can relax a little. I do have a couple follow up questions on the Pacu. Don't these fish grow to the size of the tank? From what you're telling me they'll just grow and grow and grow until they basically die (if the tank is too small). <It is not quite true that fish grow to the size of their tanks. Freshwater fish are a little easier to stunt their growth, but that is not healthy at all. How would you like to live your whole life in your closet? Get the picture.> How big of a tank do you need for a Pacu? <For any large fish, find the maximum length. The tank's width should be twice the maximum length of the fish and the tank's length should be four times the maximum length of the fish. And remember that this is a minimum. For a Pacu, 4 foot wide and 8 foot long and probably 2 or more feet deep.> I'm not necessarily "married" to the idea of getting one so I'm open to alternatives. Can you think of any? The Pacu is the exact kind of fish I'm looking for: a freshwater fish, grows very fast, grows very big and won't attack you if you put your arm in the tank! I've tried Oscars in the past but had terrible luck with them as they always got some kind of disease (ich, hole-in-the-head, etc.). I can't think of any fast growing, large freshwater fish other than Pacus and Oscars so that's why I thought I would consider a Pacu. Any suggestions? Travis <Generally, Oscars are a great fish as long as you keep their water clean with frequent, large water changes and good filtration, house them in an appropriate sized tank, and feed them a varied diet (no feeder fish). There are many other cichlids that meet you request, but they all have the same captive care requirements as above. Kind regards, Steven Pro> 

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