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FAQs on Guppy Social Diseases

FAQs on Guppy Disease:
Guppy Disease 1, Guppy Disease 2, Guppy Disease 3, Guppy Disease 4, Guppy Disease 5, Guppy Disease 6, Guppy Disease 7, Guppy Disease ,
FAQs on Guppy Disease by Category: Environmental, Nutritional (e.g. HLLE), Infectious (Virus, Bacterial, Fungal), Parasitic (Ich, Velvet...), Genetic, Treatments,

Related Articles: Guppies, Poeciliids: Guppies, Platies, Swordtails, Mollies by Neale Monks, Livebearing Fishes by Bob Fenner,

Related FAQs: Guppies 1, Guppies 2, Guppy Identification, Guppy Behavior, Guppy Compatibility, Guppy Selection, Guppy Systems, Guppy Feeding, Guppy Reproduction, Livebearers, Platies, Swordtails, Mollies,

Don't live well with fishes, plants, invertebrates that need warmer, softer, acidic water.

Beware of fishes that beat and eat guppies; e.g. "Chinese Algae Eaters", minnow "sharks", puffers, other livebearer species, Barbs, Bettas, even other Guppies

Need to be either kept as single sex or with more than 2:1 female:male ratio

Fancy guppy... beh. 7/26/2009
Hello crew, love your site I get tons of info from you guys. I have a 29 g tank with all my water levels reading right. Live stock in the tank, 2 Dwarf Gouramis, 2 Chinese algae eaters, 1 black moor,1 male Betta, 5 small Endler's and 8 male guppies.
<You do realise that Endler Guppies and Common Guppies will hybridise?
Provided you pass on any offspring as Common Guppies rather than Endler's, then there's little harm in this. But pleased don't give away such offspring as Endler Guppies! It is a constant struggle to keep the Endler Guppies in the hobby "pure" because of this problem.>
My question is why is one of my guppy's getting chased around by one other male and two Endler's? Thank you very much for any response and help you offer.
<It is in the nature if Guppies to chase. They are *not* peaceful, schooling fish. In the wild males will chase one another away, hoping to monopolise access to females. Males will also chase females, trying to mate with them. The only 100% reliable way to keep Guppies without aggression is to [a] make sure the tank is big enough, 20 gallons upwards; [b] keep two or more females per male; and [c] to stock the tank with lots of floating plants. Floating plants, such as Indian Fern (Ceratopteris spp.) are important because Guppies are surface fish, so they use hiding places at the top of the tank, not at the bottom.>
I hope this grammar is appropriate I don't want to bump heads with Neale.
<Not a question of "bumping heads" really. More about making your question, and my reply, easier for other people to read. Not all our site visitors have English as their first language. For such people, as well as those with learning difficulties, careful grammar and spelling makes reading much easier. Anyway, hope this helps! Cheers, Neale.>

Guppy problem need help soon... - 4/6/07 Hi, <<Hello, Shilpi. Tom here.>> I have a 3 gallon tank.. I have 2 Guppies one male, one female... 1 Neon Tetra... 1 Gold Algae Eater (Scavenger)... Yesterday, I saw the Gold Algae Eater going and sitting on the male guppy (Do not know if it was biting the fish or what was it probably up to?) So, I moved gold algae Eater from the tank to a different place... but the next day I saw the male Guppy with white round spot (kind of fungus) on its fin near the gills.. and the in a couple of hours it was dead... I removed the dead male guppy from the tank.. but I am afraid that remaining 2 fishes might get infected. Please tell me how to treat the tank so the other fishes are safe (I also think that my female Guppy is expecting babies)...... <<Shilpi, a Gold Algae Eater is a color variant of the Chinese Algae Eater, a fish notorious for feeding on the slime coats and flesh of its tank mates. You don't mention how old the CAE is but this murderous behavior usually manifests itself as the fish approaches adulthood. The wounds inflicted are round matching the shape of the CAEs mouth. These wounds are also terribly susceptible to fungal infections since the protective slime coat is missing. Now that I've shared the bad news, the good news is that the fungus that developed on the wound of your Guppy was already present in the tank, anyway. Your healthy fish weren't, and likely wont be, affected by it. You took care of the problem by removing the Algae Eater.>> Thanks, Shilpi <<You're welcome, Shilpi. Best regards. Tom>>

Losing Guppies 5/9/07 Hi, please say you can help my son has 2 male mollies, 2 platies, 3 guppies well 2 now and 1 male Siamese fighter. The first guppies we found dead yesterday with hardly any tail but all the others were ok now today one of the other guppies has had nearly all its tail eaten can you please help me by telling me which fish you think is killing them so I can remove it thanks Gemma <Most likely the Betta.> <Chris>
Re: Losing Guppies 5/10/07
Thank you so much we have now removed the Betta and all the other fish seem much more happy. Gemma <Good to hear.> <Chris>

Male guppies don't reach full size   06/19/07 Hi there, <Hello Kym> I have a communal tank (2 foot by one foot by 1.5 foot) which has begun to produce generations of fantail guppies (there are tetras, bristle-nose catfish and a miniature gourami in there otherwise). The female guppies grow to full size, but it appears that the males never grow as large as their fathers. they're happy and healthy and live as long as the others, but never seem to grow to full size. Can you illuminate me? <This is absolutely normal with livebearers. Contrary to the myth, breeding livebearers isn't "easy". Sure, getting babies isn't difficult, but producing quality stock requires a lot more effort. Put simply, the fry to need to be kept apart from the adults in their own tank so they are able to eat more and enjoy optimal water quality. Meals need to be 6 times per day, and half those meals should be algae-based, such as Spirulina flake. Water changes should be performed every 2-3 days, at least 10-25% each time. Nitrates must be kept low, but also various "metabolites" have to be diluted. These are chemicals fish produce incidentally to their normal metabolism. In aquaria these chemicals tend to stunt the growth of fish. Social behaviour is also important. Adult males will bully juveniles, and in doing so the resulting stress inhibits growth (in most social fish, the dominant fish tend to grow bigger, while picked-upon fish stay smaller). The bottom line is that it is almost impossible to get full-sized Poecilia spp., whether mollies or guppies, when the babies are left with the adults, unless the tank is really big and has plenty of hiding space. Your tank isn't nearly large enough, so what you're getting is small numbers of stunted guppies. That's fine just for fun, but if you're serious about breeding, setting up a 10-20 gallon tank just for fry is the way to go.> Thanks, Kym <Good luck, Neale>
Re: male guppies don't reach full size  6/20/07
Thanks very much Neale. <Happy to help.> So is the key to separate the babies, or is their growth stunted more in adolescence? <Both. Professional breeders and hobbyists wanting to rear serious numbers of fry separate the parents from the fry as soon as they can.> I don't have room for another tank, so would it help if I kept the babies in one of those breeder areas in their early life? <No, won't help at all. Quite the reverse. Those breeder nets/traps are really a bit of a con. For $5 they make people think they can rear baby fish in the community tank. They can't. Big female fish, like mollies and swordtails and even platies, get stressed when placed in them and often miscarry. If you put the babies in there, they're still exposed to metabolites in the water. They are so small that *at best* you can keep the babies in them for about 3 weeks; after that, leaving the babies in there will stunt their growth.> For how long should I keep them there if so? <Don't waste your time and money.> Or will they be bullied on release and their growth stunted regardless of the early protection? <Pretty much. A 10 gallon tank is about enough territory for a single male guppy. Any other male guppy in there will be viewed as a rival, and chased away. While you can certainly keep, say, two males and six females in such a tank, one of those males will definitely be the "boss", and any fry in the tank will be chased (and possibly eaten). You have to remember that in the wild baby livebearers don't live in the same places as adult livebearers. As soon as they are born, baby livebearers have an instinct to go into very shallow water where other fish cannot go, for example around floating plants or along the edges of the stream. Evolution hasn't bothered to produce a way for adults and juveniles to "get along" because they don't need to in the wild. This is why people get so distressed when they see mama fish eating their babies and papa fish persecuting the babies. For the mama fish, a baby fish is food, for the papa, it's a potential rival.> I guess my key question is, without a spare tank, what is the optimal or most likely way of producing full size fantail guppies? <There really isn't any way. You're basically letting Nature take its course -- but in a volume of water that is far too small. By all means carry on doing what you're doing, but you're not likely to get fancy guppies worth selling. Just a lot of fairly generic looking runts. Breeding guppies just isn't as easy as people think -- or else everyone would be doing it, and fancy guppies would cost 10 cents a pair! The other way of looking at this is an opportunity: if you invest in a 10 gallon tank and rear a few batches of good quality fish, after selling those fish, you'll pay off the investment. Ask your retailer what they would pay for good quality stock, and figure out for yourself whether that income would pay for the outlay on another tank. If it will, then that's the way forward.> I guess this means - is early development the key, or adolescent development? <Both.> My tank has a lot of plants and many places to hide. <Doesn't make a huge difference in a 10 gallon tank. Metabolites will still be in the water, and even if the fry can hide from an aggressive male, they're still stressed.> Thanks again, Kym <Cheers, Neale>

Dead pregnant guppy  8/16/07 Hi, <Hello.> I had a pregnant fancy guppy who was in fine health. I put a new male fancy guppy in the tank with her 2 weeks ago, he was quite active and a bit aggressive which is why I chose him, as my previous male guppy had been picked on by my tetras. (I have 3 balloon mollies, 2 painted tetras, 1 Pleco, and these 2 guppies). <Surely the better solution would have been to remove the tetras? Painted tetras are, I believe, albino Gymnocorymbus ternetzi that have been injected (into the muscles) with fluorescent dyes. Do you realise that this is done without anaesthesia and large numbers of them die in the process? It also weakens their immune system. It's possibly one of the nastiest and more venal aspects of the fishkeeping hobby, and if I could, I'd run up to the guys who do it and inject their muscles with massive amounts of fluorescent dye and see if they liked it! Please please please do not support this evil trade, and do not buy painted fish. In addition, Gymnocorymbus ternetzi are notorious fin-nippers. A guppy is a swimming buffet as far as they are concerned.> The male had always 'bothered' the female and constantly swims by her side (maybe trying to mate??). She has given birth before (by mating with my previous male) and been fine afterwards. <Yes, he's partly trying to mate, but he's also "guarding" the female to prevent another male from mating with her. This way, he monopolizes what, in his mind at least, is a limited resource: fertile females. Now, guppies should ALWAYS be kept either as single sex groups or in mixed sex groups where the females OUTNUMBER the males by at least 2 to 1. No-one listens when experienced fishkeepers tell them this, because they think it's cute to have a boy and a girl, and the boys are prettier anyway. And then, they end up with stressed or dead female guppies.> I did a 30% water change 36 hours ago and they all were acting fine. She may have had a slight decrease in appetite, not too sure. I did not see any signs of health problems with her. She was a big slower due to her swollen belly. In any case, I came home today to find, sadly, my pregnant female guppy dead with her tail and fins bitten off. <Well, the Gymnocorymbus ternetzi may well have eaten her fins, and the Plec will eat a dead fish given the chance.> I was expecting her to give birth within a week or so. (I'm so sad she died!). <Yes, I understand, and I'm sorry for your loss.> 1) Is it possible the male killed her?? If so, how can I prevent this in the future? I'd prefer not to get him more females as I am afraid of overloading the tank. <Yes, the male could well have stressed her. In a small tank (anything less than 20 gallons in this case) the female would have had no place to hide. He would stress her by chasing, and also preventing her from feeding properly. While male guppies generally don't kill the females outright, what they do is make it more difficult for the female guppies to stay healthy.> 2)The male guppy is now swimming alongside the mollies and bothering them... Is he trying to mate? Does he need a female guppy's company? <Yes, he's treating the mollies as if they were guppies. Mollies and guppies are members of the same genus, Poecilia, and will even (occasionally) hybridise. Both guppies and mollies should be kept in groups. They aren't schooling fish as such, but they are sociable.> I'm very upset about her death, and would really like to prevent it from happening again. Any advice would be greatly appreciated. Thanks! <My advice is that you go buy or borrow a book about Livebearing fishes. Or at the very least read some of the articles here at WWM (see here: http://www.wetwebmedia.com/FWSubWebIndex/fwlivestkindex.htm  ) on the subject. Lots of people get even the basics wrong. These fish need hard, alkaline water. Some (mollies for example) need brackish water to do reliably well. All are more or less herbivorous, so at least half the diet should be green foods, not standard flake. Get these things wrong, and livebearers won't do well. Simple as that. Cheers, Neale>
Re: dead pregnant guppy  8/16/07
Update: I decided to try and dissect the female to see if I would see any eggs/embryos in her, and when I dissected near what I thought was her gravid spot I did not find anything (however, it was a messy, not too accurate dissection... I don't usually keep a mini dissecting kit around =)) Anyways, I found some pale yellowish gel-like liquid, and other organs/intestines... nothing resembling offspring, although I'm not too familiar with fish anatomy. Is it possible she wasn't pregnant? I noticed her 'gravid spot' getting larger and darker in the past couple of weeks, and she definitely looked more swollen this past week. I did not see what she looked like the last time she was pregnant, so this was my first time observing what I thought was a pregnant female. <Interesting. To be fair though, after a couple of hours in a tropical aquarium, decay of the insides of a fish is significant, and you won't see all that much. So it's difficult to explain things from your observation. Female guppies when kept with male guppies are almost always pregnant, but at the early stages of gestation the fry are very small and difficult to see.> Also, could the water change have been too stressful for her? I had my hand in the tank to move around some of the plants/decorations and fix the filter orientation. It took about a half an hour. <Water changes, done properly, aren't a problem. Even a 100% water change is fine. What matters is that the pH and hardness of the new water and the old water are very similar, and the temperature difference is small (a sudden drop in temperature by a degree or two is harmless, and even therapeutic, prompting many species to spawn).> Thanks again for your help! <Good luck, Neale>
Re: dead pregnant guppy 08/17/07
Thanks for taking the time to respond. Very helpful!! I will try to remove the tetras, although I could only return them to the pet store, so I don't know if this is possible. I don't really have the resources to get another tank. My friend actually bought me the painted tetras as a present, neither of us knew how inhumanely the fish are treated in order to dye them... I definitely will not support this in the future. Best case scenario, I can return the tetras and get 2 female companions for my male guppy. Thanks again!! <Happy to help. It sounds like you have a plan. And I'm glad you aren't going to buy any more painted fish. I don't blame the fishkeepers, as they're usually unaware of the problem. But the retailers are surely aware of the problem by now, as it's been in the open for years. So it's really up to them to stop stocking them. I'm sure most fishkeepers wouldn't buy painted fish if they knew how they were painted. Good luck, Neale.>

Guppy with Popeye   2/1/06 Dear wet web media, <Leslie>     I have a Guppy that has had Popeye for approximately 2 weeks. We had some aggressive Serpae tetras at the time, and I assumed it was due to the nipping they were doing. <Maybe> Immediately upon noticing the condition, I moved him to a fish bowl I have. It was the best I could do for a QT tank.  I treated him with Epsom salts per your instruction in the FAQ section of your website.  The eye has improved some, and he has started to eat (he wouldn't eat at first).  There was a red ring under his eye for about a week, which has gone away, but  I have still left him in QT because the LFS told me that Popeye is sometimes caused by a parasite, <Mmm, very rare actually. If one sided, a trauma or aggression almost always... if bilateral, typically environmental in cause> which eventually comes out from behind the eye.  If it was a parasite, I did not want that released into my main tank.      Basically, it has been two weeks and his eye is still bulging.  The swelling has not gone down much.  Should I treat him with something else, or should I just let him be.         Thanks,      Leslie <Mmm, some expense involved, but antibiotics can be attempted... Covered on WWM... search under Popeye, Freshwater. Bob Fenner>

Mmm, FW guppy damage  9/10/06 Hi. <<Hi, Joanne. Tom>> I hope you may be able to answer  this question for me. <<I'll give it my best, Joanne.>> I  have a 180 litre tank in which I currently have 11 Neons and 18 assorted male  guppies. The tank is heated, has an internal filter, airstone and fluorescent  lighting. My water quality is good and I have had no problems. <<11  Neon Tetras and 18 Guppies in the U.S. equivalent of a 48-gallon tank? Joanne,  if I weren't happily married, I'd kiss you! We spend so much time telling  hobbyists to get larger tanks for their pets that it's a breath of fresh air to  have someone write in that has provided room to spare for their "charges". Well  done!>> The fish shoal and seem happy, until now. Last night I realized  I was missing one of the fantail guppies. I have 6 of these. The fish in  question I had always classed as the alpha male as he had the most beautiful  tail! <<"Alpha-ness" is more behavioral than physical but I understand  your thinking...>> I eventually found him hiding and his tail was  virtually gone. <<Uh oh...>> What remained was in tatters and  he was obviously scared, seemed to be shaking and he died minutes later.   <<Sorry to hear this, Joanne.>> I haven't been able to find  any info that says the other guppies would fight without females present.   <<Not likely that you would, Joanne. In the world of Guppies, the  females do the 'selecting'. The "boys" will show off and try to attract the  attention of the females but an Alpha female is known to kill a male, or males,  that she deems unacceptable for breeding.>> This only happened after I  had added some more guppies 2 days before. <<It's possible/plausible  that the males may have fought over the "right" to breed, whether, or not,  females were present. The new additions may have triggered this response but,  frankly, this is speculation on my part.>> Is it possible they did  this?   <<Highly unlikely, though not impossible, that one, or  more, of the new Guppies did this. Typically, the "established" fish have, or  display, dominance over fish that are subsequently added to the aquarium.  (Timing can be very important when adding fish.)>> If so, do you know  why and, can I prevent this from happening again? <<An educated (and I  use the term loosely) guess is that the established Guppies viewed the new fish  as potential breeding partners. The "subordinate" males went after the most  likely candidate (the He-Bull, in a manner of speaking) in order to increase  their standing with the "females". Since the "predominant" male is most likely  to be chosen to mate with a female, it makes sense, from the fishes' points of  view, to get rid of the biggest competition. Whether, or not, utilizing a tank  divider to keep the new fish separated from the older ones is really academic.  In a sense, you'd be trying to cheat "Nature". (You might like to see a Great  White Shark live harmoniously with a seal but, it isn't going to happen.) Bob  would have a more eloquent explanation but the fact is that, in some cases,  Nature must run its course.>> Thank you in advance Joanne  x
Re: Mmm, FW guppy damage  9/10/06
Hi Tom, <<Hi, Joanne.>> Thanks for your reply. It was nice for someone to appreciate that I was trying to keep my fish happy by having a large tank, rather than people telling me I need more fish in there! <<First, you're most welcome. As for your tank, you have plenty of "fans" here at WWM! If more folks followed your lead our mail would be cut by 30%, at least.>> I wanted to update you, since the sad demise of my favourite guppy I spent a lot of time sat in front of the tank watching their behaviour, sad I know. <<Not true! I can't pass either of mine without stopping to check things out.>> I did notice a newer addition behaving quite aggressively towards some of the other guppies. After half an hour of tail nipping I separated him for 10 minutes and then reintroduced him, mainly as he didn't seem pleased and I felt bad about it! <<Sure he wasn't pleased. You took away his "chew toys". Interesting that one of the new additions appears to be the culprit. That certainly wasn't my take on the situation, was it? Unusual, but I should be used to fish doing things out of character by now. (I believe they do it to embarrass me.) :)>> He had calmed down and since then the guppies have resumed their playful existence, much to the delight of my 9 month old daughter! <<Excellent. Good move, by the way.>> I must add also that I 'lost' 5 of the newly introduced guppies. I had bought them from a store I had not been to before, nor will be returning to as the assistant who netted the fish did not seem concerned for their welfare and I wish I had walked away as instinct told me to. <<I think we've all had purchasing experiences like that. I certainly have, regrettably.>> I have never lost a  fish before as I always take the utmost care of them and found it quite distressing. My tank readings are optimal so I know it isn't a water quality issue and can only assume that they came from a bad batch or were stressed beyond recovery. <<Considering what many fish go through before coming into our hands, it seems nothing short of a miracle that more aren't lost.>> I will wait a few weeks before adding any more and will stick to my regular stockists in future. <<A wise choice.>> I also wanted to say that I have found this site invaluable, the best by far on the net! Thanks again Joanne <<Nice chatting again, Joanne, and thank you for your kind words. Keep up the good work! Tom>>

Re: Losing Guppies   9/16/06
Hi, <<Hi, Joanne. Tom again.>> I hope you can help me. I have spoken with Tom before and have attached my previous correspondence below. I am losing my guppies one by one and I cannot figure out why. I have examined them after death and watched them in life, they don't show any outward signs of disease, no bloating, fungal growth, etc. The only visible sign I am about to lose one, is that the tail rapidly becomes very ragged, this happens literally over the space of 24 hours and then within another 24 hours the fish is dead. <<Joanne, almost certainly this is a bacterial infection. The "invasion" begins in the tails causing the rapid deterioration you've observed and moves, through the blood streams in the tails, into the bodies of the fish.>> I am finding this distressing and against the advice of family I haven't used any 'universal' treatments as I prefer not to use any chemicals unless it is absolutely necessary. <<We're at the point where medication is necessary, Joanne. Separate the Guppies, if possible, and treat with Tetracycline, Maracyn or Maracyn-Two. While Guppies are quite tolerant of salt, Neon Tetras are not, so avoid the temptation (if it exists) to add salt as a preventative/preemptive measure for the Neons.>> The neon tetras who share the tank seem to be spared the same fate and are positively thriving. I have tested the water and it is as it should be. Any ideas? <<One of the things that I should have considered earlier is that Guppies and Neons actually prefer different water parameters with the Guppies requiring slightly hard/alkaline conditions and the Neons doing better in softer, slightly acidic water. Both can adapt to conditions somewhere in the middle but this might account for the demise of the other Guppies. Depending on the water conditions they were adapted to at the fish shop, they may have been stressed, even shocked, when transferred to your display tank. Speculation, obviously, but I'm trying to offer an explanation for what has opened them up to this infection.>> Many thanks Joanne <<Sorry that you're faced with having to medicate your fish, Joanne, but I see no other option at this point. Best of luck to you and your pets. Tom>>

mail... Male? guppy tail   10/4/06 Hi,   <Hello there> I have been successfully "in line" breeding my guppies for a while now. I am now on about the 4th generation of father to daughter and now brother to sister breeding and so on... <What it takes to "fix" a line...> the cross colors become more brilliant down the line!! I have a male who is my favorite, and both his father and mother have already died. Recently my step son did the ultimate no-no (without my supervision) and stuck our isolated Betta into the community guppy tank. My first reaction was to get the Betta out of there. After a quick observation, I noticed that my Betta was content, and there was no aggressive behavior <Happens... but...> in the tank. I did not have time to get the Betta out, as I was just leaving for work and could not afford to be late!! My son was also going to school, so I had no option but to leave the Betta in the tank, until I got back home. If I could only buy extra time!! That evening when I got home, my favorite mail guppy was missing his beautiful fancy tail. <Argghhhh> It was bitten almost down to nothing, and completely gone. The skin/body is still ok...there is just a small nub of a tail that is left. Is there any chance of his tail growing back? <Mmm, not much if it is all the way down this far> If so, how long does it take to grow, and what can I do to help him survive without his tail?? <The usual "good care"... water changes, frequent feedings...> Will the colors change if it does grow back? <Possibly... but I doubt if it will regenerate. "Only time can/will tell"> He is rather a small guppy, one of my younger. I just hope I can save him, because his parents are gone, and he had an amazing tail color, unlike his brothers!! Of course I took the Betta out ASAP, and had a talk with my step son about the Betta who is better off alone (he thought the Betta was "lonely") my step son is only 5. Please, any input would be greatly appreciated!   Lisa   <Wishing you all well, Bob Fenner> 

Re: Platy and Plant problems... now Guppy and Molly...  9/18/06 Hello Mr. Fenner, <John> Thank you so much for the reply regarding the plants and platy.   I will not treat the platy at the moment then, rather I will wait and observe.  I have a bubbler going in the aquarium to disturb the surface water and reduce the stress resulting from her breathing. <Good> On an unrelated and recent issue, a Sailfin molly has attacked one of my guppies and devastated the tail fin (pictures attached). <Yikes, I see... not uncommon... male fancy guppy tails are something akin to bullfighters' capes>   I have removed this aggressive molly from the tank and am now wondering if there is something I should/could be doing for this injured guppy.   Should I be adding some form of prophylactic treatment (i.e. aquarium salt - could also help with the increased respiration of the platy?) <I do think this is a good idea> or treating with mild antibiotic in this case to prevent infection?  The tail seems incredibly damaged to me. My best to you & the WWM crew. <Thank you. I would leave off with antibiotic use here... am more a fan of saving this/these for advanced infectious problems. Bob Fenner>

Bully Guppies?   9/11/06 Hi. <<Hi, Joanne. Tom>> I hope you may be able to answer this question for me. <<I'll give it my best, Joanne.>> I have a 180 litre tank in which I currently have 11 Neons and 18 assorted male guppies. The tank is heated, has an internal filter, airstone and fluorescent lighting. My water quality is good and I have had no problems. <<11 Neon Tetras and 18 Guppies in the U.S. equivalent of a 48-gallon tank? Joanne, if I weren't happily married, I'd kiss you! We spend so much time telling hobbyists to get larger tanks for their pets that it's a breath of fresh air to have someone write in that has provided room to spare for their "charges". Well done!>> The fish shoal and seem happy, until now. Last night I realized I was missing one of the fantail guppies. I have 6 of these. The fish in question I had always classed as the alpha male as he had the most beautiful tail! <<"Alpha-ness" is more behavioral than physical but I understand your thinking...>> I eventually found him hiding and his tail was virtually gone. <<Uh oh...>> What remained was in tatters and he was obviously scared, seemed to be shaking and he died minutes later. <<Sorry to hear this, Joanne.>> I haven't been able to find any info that says the other guppies would fight without females present. <<Not likely that you would, Joanne. In the world of Guppies, the females do the 'selecting'. The "boys" will show off and try to attract the attention of the females but an Alpha female is known to kill a male, or males, that she deems unacceptable for breeding.>> This only happened after I had added some more guppies 2 days before. <<It's possible/plausible that the males may have fought over the "right" to breed, whether, or not, females were present. The new additions may have triggered this response but, frankly, this is speculation on my part.>> Is it possible they did this?   <<Highly unlikely, though not impossible, that one, or more, of the new Guppies did this. Typically, the "established" fish have, or display, dominance over fish that are subsequently added to the aquarium. (Timing can be very important when adding fish.)>> If so, do you know why and, can I prevent this from happening again? <<An educated (and I use the term loosely) guess is that the established Guppies viewed the new fish as potential breeding partners. The "subordinate" males went after the most likely candidate (the He-Bull, in a manner of speaking) in order to increase their standing with the "females". Since the "predominant" male is most likely to be chosen to mate with a female, it makes sense, from the fishes' points of view, to get rid of the biggest competition. Whether, or not, utilizing a tank divider to keep the new fish separated from the older ones is really academic. In a sense, you'd be trying to cheat "Nature". (You might like to see a Great White Shark live harmoniously with a seal but, it isn't going to happen.) Bob would have a more eloquent explanation but the fact is that, in some cases, Nature must run its course.>> Thank you in advance Joanne x <<I hope I've been of some help, Joanne. Tom>>

Tail fin decrease in guppy Hi. I have a major problem with one of my male guppies. He is a green cobra guppy. Anyway I just bought him yesterday at the local pet store and he looked very healthy. When I woke up this morning I noticed about 90% of his tail fin was gone. I believe he is going to die soon. Please help me so if he dies I know what to do in the future.     P.S I predict that one or two of the females in my tank ( 20 gal.) is responsible for this Tell if this prediction is Correct. < I don't think so. A power filter intake tube may have caught his tail. Barbs and Bettas can do this kind of damage too. I suspect it may be tail rot caused by a bacteria infection. Isolate the fish and see it gets worse. If it does then it is rot and you need to treat it with antibiotics like Furanace or Erythromycin.-Chuck>

Sick Guppy  3/21/04 Hi, I have a sick guppy that I don't know how to treat, I'm not even exactly sure what is wrong. Hoping you can help me. I moved him to my 10 gal. QT tank 4 days ago because I noticed his poop looked funny. Sometimes it comes out clear, stringy, and with some white globs. Which I've read is indicative of internal parasites. <Yes, those can be the symptoms, along with eating & still skinny or not eating at all.  The problem is, guppies aren't wild-caught fish & rarely come with internal parasites.><<Au contraire. RMF>> Sometimes it comes out like a tan/orange color and is very thick and curls up when it is a long  string of it. It is so thick it actually looks like it would be very painful for him to pass it. It doesn't appear to be a worm or anything though. It's odd because I have had him for about 4 months now and he has always been very healthy and hardy and active. Even survived an Ich outbreak (due to buying infected fish without QT first) in my main (46 gal.) tank without getting one spot. This was before I realized the importance of a QT tank, and treated the Ich outbreak in my main tank. How could he have gotten sick? Could it have been from stress from my tormentive Mollie? <Could be.>   I read that food laced with Metronidazole would be an effective treatment. However, I could not find any so I bought some Parasite Clear fizzing tablets made by Jungle. I treated once, and then did a 25% water change. He then seemed to be eating more and his poop looks like it is trying to return to normal but it has still got some areas of clear, white string in it. He is swimming around a lot more now, seems like he feels somewhat better. His tail was also looking a little ragged it had one rip in it, but I thought if I cured him his tail would cure itself. But now his tail is getting worse. It is becoming more ragged and has two blood spots in it. Twice now I have even seen a little bit of blood float off into the water when he moved. I have some Fin rot medication should I use this? And should I treat with the Parasite Clear again? <Internal parasites can only be treated internally, by treating the fish's food.  By the fact that the Jungle product made your fish feel better, I don't think this is the problem.  I really think your molly is the problem--they can be quite vicious.  Your guppy felt better because the molly wasn't bothering it anymore.  Starting treating you guppy with a combo of Melafix & Pimafix for it's tail.  I'd find a new home for the molly.> Thanks so much! Stacie <You're welcome & good luck.  ~PP>

Sick guppies        Hello, I'm having a problem with guppies dying. They are in a community tank (20 gal) with a couple mollies, two white clouds, a SAE, and a 1-inch fw puffer (adult size, no worries, he doesn't even try to eat the baby guppies). >>Hello :D I think will eventually have a problem with keeping puffers and guppies together. Puffers are notoriously aggressive fin nippers, and will start shredding tails at some point. The mollies can also be quite aggressive. What is the scientific name of the puffer? (Tetraodon travancorius?) These are two species that I would NEVER recommend to put with guppies, as generally, guppies should be only kept with non-aggressive fish.<< Oh, and there are currently two adult male and two adult female guppies (the number of small guppies varies with time, of course... maybe three tiny guys right now). This problem has been going on for a couple of months, and I'm at the end of my rope trying to figure it out/solve it. The symptoms are rapid breathing and progressive loss of energy, and a decreased interest in food. Some of the fish occasionally flick against the bottom. Only the guppies show symptoms/die. >>Normal, since guppies are the least resilient fish you have in the tank.<< I've treated the tank with Maracyn and Maracyn 2, thinking that this is an infection of the gills, but no success in eradicating it- every few weeks another fish starts having breathing problems. I have added aquarium salts to the tank (tsp/gal), having read that that will help with the breathing and should make an inhospitable environment for the infecting agent... not inhospitable enough, apparently! I have checked my water quality for pH and ammonia- 7.4 and 0 ppm (comes out of the tap at 7.2ish). I change the water regularly (every 1 to 2 weeks). >>You will need to treat with an anti-parasitic medication, like Super Ich Cure, or Quick Cure. I like Quick Cure because the Formalin in it helps against gill flukes. Remove your carbon, of course. Your pH is a tad low for mollies, and perhaps the puffer, too, depending on the species of puffer you are keeping. You have tested ammonia, but what about nitrite and nitrate? We really need to know this. Nitrite is just as toxic as ammonia, and a nitrite spike can last quite a long time. How much water do you change? What percentage, that is..<< Part of the reason that this has gone on so long is that only one fish at a time ever shows symptoms then dies, so I've thought that I had cleared up the problem previously, only to go through the same agonizing process a week or so later. Also, a friend who has many years of fish experience told me not to worry, that the guppies that were dying were probably just old...  >>I doubt this.<< I won't take advice like that again from anyone who regards my fish as just a food source for bigger fish! It's now affecting fish that I know are only 7 months old. Please help if you can! I feel so awful watching them get sicker and sicker, not knowing what else I can do for them! Thank you! Sarah O PS I think I comb through your site about once a week, learning a bit more about aquaria and fish each time. It's a great resource, thank you for providing it! >>As I mentioned, go to your local fish store and buy an anti-parasitic medication. Your fish have gill flukes, a parasite. -Gwen

Guppies dying We have a 120 gal. tank with guppies, Neons, catfish, platies, rainbow or red tailed sharks, and algae eaters. In the last 5 days 6 of our guppies have died. All of the other fish are doing fine. We had a female die giving birth 5 days ago, only 4 made it. Ever since then guppies have been dying everyday. Why are the guppies dying and not the others and what could the problem be? <It could be any number of things. The first thing to do is check your water quality. I'm assuming the dying guppies are showing no signs of disease? Sometimes this will happen for no explainable reason. I have noticed with my own Guppies that every once in a while they will go thru a period that I will lose several in a row even though everything is fine. Ill go thru a week or so period losing a bunch and then it will stop and I wont lose any for months. I still haven't been able to figure out why this happens. Sorry I couldn't give you more info! Ronni>
Re: New Tank Problems and General
It seems my Ph was off. I have bad eyes. It took me a few hours but I got it neutral finally, and I plan on doing a 20% water change soon. My store is giving me a refund on my 2 guppies (14 day guarantees are so cool). Ill keep you posted :) -Ray in Texas <Glad you were able to pinpoint the problem and that your store is working with you. Good luck! Ronni>

Guppy problems First, thank you VERY much for taking the time to review this.  I looked online all night and was nothing but confused by the end of it.  I'm a new guppy owner and am very inexperienced.  I have a 20 gallon tank with about 25 guppies, 1 apple snail, 1 Chinese algae eater, <Keep your eye on this last fish... can become predaceous> 6 neon tetras.
<Live in different environment... warmer, softer, acidic water...>

  I started the tank and added the bulk of the guppies and tetras about 2 weeks ago.  I haven't tested the pH, but I did use a stabilizer when starting up the tank.  I now know that I probably should have waited longer for my tank to set up.  Three days ago, my neighbors gave me a few more guppies, an algae eater and a snail.  Everyone was fine until the day before yesterday.  I noticed on Monday night that a group of girls were hanging out at the top of the tank - bunched up together and not moving much.  I initially thought that maybe they were pregnant - I have no idea how to tell if they're pregnant. <Have a read here: http://www.wetwebmedia.com/FWSubWebIndex/guppyreprofaqs.htm> Yesterday, I noticed the same group of girls hanging out at the bottom of the tank.  I also saw that there were new fry in the tank and thought maybe that had been the reason for their odd behavior.  However, I then noticed one female guppy swimming on her side (looking drunk), and another female, pretty skinny, swimming around with her tail fin closed and her skin very pale.  This morning, it looked like there were a few more females joining the group at the bottom of the tank - none with the symptom of the other two, but they move very little.  I know I must not be doing something right, but I'm nervous to make any drastic moves without sound, specific advice, afraid that I might make matters worse.  I also have about 6 tsp of salt in the tank.  Please let me know what I should do. Thank you! Liz <At this point, read. Re freshwater set-ups, stocking, but particularly establishing nutrient cycling: http://www.wetwebmedia.com/FWSubWebIndex/fwestcycling.htm You likely want to invest in some water quality test gear. Bob Fenner>

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