Logo

Wet Web Media is a Reference site and best used with the following tools
Step 1: Search us with Google
Step 2: Enter terms of interest to highlight
Home
Information Pages:
Marine
Aquariums
Freshwater
Aquariums
Planted
Aquariums
Brackish
Systems
Ponds, lakes
& fountains
Turtles &
Amphibians
Aquatic
Business
Aquatic
Science
Features:
Daily FAQs
FW Daily FAQs
SW Pix of the Day
FW Pix of the Day
New On WWM
Helpful Links
Hobbyist Forum
Ask the WWM Crew a Question
Calendars
Search Feature
Admin Index
Cover Images


FAQs on the Black Skirt/Widow Tetras, Gymnocorymbus ternetzi

Related Articles: Cardinal Tetras; A School of Beauty, Part II,  by Alesia Benedict, Characid Fishes

Related FAQs:  Cardinal Tetras, Characid/Tetra Fishes,

Zebra danios versus white-skirt tetra?      2/16/14
Hi wonderful people.  Thank you once again for running this marvelous site!
 I have what is hopefully a simple question.
<Let's see>
I just set up my first freshwater low-tech (low light, no CO2) heavily planted tank, 46 gallons.  I cycled it fishless (ammonia method), which went incredibly well.  I don't know why more people don't do it that way, as it is so fast and easy. 
<Agreed>
After just three weeks I can put in ammonia to 2 ppm, and in 8 hours ammonia and nitrite are unmeasurable.  But I digress.
<Take your time; we are all friends here>
I initially stocked it with 5 albino bronze Cory cats, who seem to be happy and healthy.  I was browsing the LFS with my wife, and she squealed in glee when she saw the GloFish.  My heart sank.  Over my dead body.  But she has been so wonderful to me, allowing me to have three reef tanks and now a freshwater tank all over the house, that I just can't say no to her pleading to get a school of them.  Sigh.
But here's my question:  They have two varieties of GloFish, Zebra danios, and Tetras (white-skirt I think, but not positive).
<Yes; Gymnocorymbus ternetzi... modified>
 In terms of care (feeding ease, health, proper social behavior), which do you think would be easier to keep?
<The Zebra Danios; but they're both close... the Blackskirts/Tetras being a bit more nippy>
One added factor is that I think I have room for one or two of some other 'feature' fish, and I'd love to get something striking in a different way. 
A pair of Angels would be nice, but their temperature doesn't overlap enough with danios.  A male Betta would be nice, but I'm sure it's tail would get nipped.  Maybe a pearl gourami or two?
<These last, Trichogaster leeri; would be best w/ either of the two gene-clipped onto fishes>
Any advice, especially on Danio versus tetra, would be deeply appreciated. 
Thank you in advance!
<Welcome. Bob Fenner>
Tim
Re: Zebra danios versus white-skirt tetra?      2/17/14

Bob - Thank you.  You and the folks here are wonderful!  If I may, I have one quick follow-up.  From my research around the net and in some books, it appears that the white-skirt tetras are more tolerant of pH swings than zebra danios.
<Mmm; I'd rank them near the same... both species have been under human culture for four or so decades... tolerant of human abuse>
  Even though my tank is completely cycled, it's still young, and over a 24-hour period its pH swings between 7.4 and 7.8, which concerns me a little.  Do you think danios can handle this better than the tetras? 
Thanks!
<I would say so; yes. BobF>
Tim
Re: Zebra danios versus white-skirt tetra?

Bob - Thank you!
Tim
<Ah, welcome. BobF>

Black  Skirted Tetra can't eat    4/1/13
Hi,
I have had a 55 gallon tank for six months- I bought it complete with fish at a yard sale- so far so good.  Except now my black skirted tetra can't eat. S/he tries to eat but the food falls out of its mouth.  My fish is starving.
No ammonia or nitrites. PH around 6.5. I have a pretty consistent nitrate issue. 40-60ppm.  Probably from over feeding or maybe from the snail infestation I deal with.
I don't see any growths or protrusions on my Black Skirt and the rest of the fish are happy.
Any ideas why my fish can't eat?
Cheers,
Reese
<Can the fish take food into its mouth? In which case, if it can, but then drops or spits out the food, try alternative foods and/or smaller-sized foods (even hard boiled egg yolk can work great, despite the tiny particle sizes). But if the fish cannot take food, it may have damaged its jaws.
Fish almost never recover from physical damage of this type, but do review "Mouth Fungus" (actually, a bacterial infection more often called Columnaris these days, caused by Flexibacter bacteria), and if that seems likely, treat accordingly. But otherwise a fish with dislocated or damaged jaws is unlikely to survive, so should be euthanised: 30 drops clove oil in 1 litre of aquarium water makes a good killing bath that sedates the fish (in minutes) then kills it (leave in bath for 20-30 minutes). See here:
http://www.wetwebmedia.com/euthanasia.htm
http://www.wetwebmedia.com/euthanasiafaqs.htm
Cheers, Neale.>
Re: Black  Skirted Tetra can't eat     4/2/13

The fish tries to eat, it appears the food falls out. I have switched to micro pellets and still it can't swallow.
<Not good.>
I will look into "Mouth Fungus."
<Do, but don't get your hopes up. It is possible to force-feed fish, which may help if you're medicating. Im brief, the aim is to take a very small piece of something soft (shrimp is good) and then force it into the mouth by holding the fish down (preferably underwater so your hands are wet) and then use something like a blunt cocktail stick to push the food into the
gullet (not all the way down, just far enough it doesn't fall out or get spat out). Once successful feed is adequate, and because this is stressful and likely to damage very small fish, it isn't recommended for casual aquarists. An adult Black Skirt Tetra is borderline big enough to be do-able, but still, be careful.>
Thank you for the prompt options. I appreciate it as I hate to see the fish suffer. Best, Reese
<Glad to help, Neale.>
Re: Black  Skirted Tetra can't eat    5/6/13

Hey!  Thank you so much for responding to me!  I treated the tank for fungus and it helped my tetra.  He is swimming around, happy and eating well. He looks shiny and colorful.
I'm so relieved that s/he is OK!  I'm truly  grateful for your advise.... And so are my fish:)
Best!
Reese
<Hi Reese. So glad things turned out so well! You must be doing a good job!
Cheers, Neale.>

possible prolapse?      8/14/12
The black skirt tetra in question developed the condition sometime earlier today. After a little research, it appears to be a prolapse. She (he?) is acting perfectly normal and is still eating. I tested the water and it appears to be fine: 0 ammonia, 10ppm nitrate, 0 nitrite, GH 75ppm, KH 80ppm, pH 7.5. Is it a prolapse or something else? What should I do? A
quick response would be greatly appreciated. Thank you in advance.
<Yes, you do seem to have a Black Widow Tetra with some sort of intestinal infection. As the pathogens (often Protozoans rather than bacteria) multiply, they cause the large intestine to become inflame and emerge from the anus. Metronidazole ("Flagyl") is the medication of choice here, and the only one that works reliably. The use of Epsom salt can be helpful too, at 1-3 teaspoons per 5 gallons/20 litres, alongside the Metronidazole.
Cheers, Neale.>

Great pix. B

Angelfish and Black tetra    7/20/12
Hi, I have a 55 gallon tank with two angelfish, 9 cherry barbs, and 2 Raphael's. I want to add a few black skirt tetras, is that possible? Will they get along with the angelfish?
<Black Skirt Tetras (Gymnocorymbus ternetzi) are fin-nippers. I would not trust them with Angels; in fact I kept them together in my first community tank some 25 years ago, and the Angels were nipped!>
Thank you!
<Most welcome, Neale.>

Jelly-bean Tetra and Mexican Biotopes 7/11/12
Hey there, WWM crew! I'm back again to pick your genius brains for information that I can't really seem to find elsewhere! I have questions on two totally unrelated subjects for you today, and am hoping you can help sort me out as you always have done so well!
<Will try.>
First, I have the opportunity to purchase a school of very beautiful and tiny Jelly-bean Tetra.
<Now, what are we talking about here? The artificially coloured form of Gymnocorymbus ternetzi (the Black Skirt or Black Widow Tetra)? These are very widely sold in the US, but thankfully absent from the UK trade. They are tattooed with dye into the muscle underneath the skin. It's a cruel, dangerous process and I would suggest you should not buy these fish! Or do you mean Ladigesia roloffi, a rarely-traded tiny (~3 cm/1.2 inches) species from Africa? This is a lovely fish, somewhat delicate, and does need soft, acidic water to do well.>
I've fallen in love with these little dwarfs, and I think they'd be the perfect finishing touch to my soft-water community tank. . . but I'm having a bit of trouble finding very much information on the species. It seems that they're very rare in the trade (at least around here),
<Yes.>
so I'm wondering if you can link me to any articles or just tell me what you can about these pretty little fish.
<There's a great summary over at Seriously Fish, here:
http://www.seriouslyfish.com/species/ladigesia-roloffi/
But the basics are simple enough. Water chemistry needs to be soft (1-10 degrees dH), and the pH slightly acidic (6.5-7). Middling water temperature is fine, 25 C/77 F. Feeds on tiny live foods (like Daphnia and Cyclops) and their frozen substitutes, but will take flake once acclimated to aquarium conditions. Highly social, so keep a decent sized school, I'd say much more than 6, and really at least 8 to 10, and ideally more. Terrified of larger midwater species, but gets along fine with bottom dwellers that stay away from the middle of the tank, such as Corydoras and Apistogramma. Should also work fine with small midwater fish like Threadfin Rainbowfish or Golden Pencilfish.>
They will be the final addition to my well-planted, established tank.
Nitrates stay steady at 7.5, and the substrate and background are dark. Lots of open swimming room for them (planned into the aquascape) and floating plants. The other creatures that live here are 4 Bolivian Rams and a small shoal of 5 Kuhli Loaches, so they'd pretty much have the top of the tank to themselves. Also, I believe these were wild-caught, and according to the shop owner have been QT'd and medicated before being put up for sale (though I'd QT them anyway, of course) I've never owned a wild-caught fish before, are there any special rules to follow here? Have you any information to offer or advice to give?
<With wild-caught fish, your main problem is feeding: they have no idea what flake is! So be ready to offer live foods, perhaps newly-hatched brine shrimp if you want the cheap and easy approach and have a few days prep beforehand. So long as they're not competing with midwater fish, you shouldn't have any real problems here.>
My second question is this. . . I'm still working out what to do with my Mollies! They do still live in my main tank, but will be transferred to their own tank when the tetra (or whatever fish I end up with to complete that tank) are through their QT period, and that tank is finally open. The plan is to turn the QT tank into a Molly paradise, complete with salinated and hardened water.
<Sounds ideal.>
But I've done the community tank, and now I'd like to try my hand at an authentic Biotope. As far as I have been able to figure out, Mollies originated in Mexico - but I can't seem to find ANY information on what a freshwater (or brackish) Mexican Biotope should look like.
<Ah, because they live all over the place! Not necessarily -- or even most commonly -- brackish water. But any open, sunlit pool or stream is good Molly habitat. The perfect environment in the aquarium would have something like lots of flat rocks, bright overhead light, plenty of algae growing on the flat rocks, and if you want them, some tall plants around the edges of the tank for shelter and shade (females and fry appreciate this) -- I'd look at things like Vallisneria and Amazon Swords (most of which don't come from the Amazon!) as examples of plants that tolerate hard or slightly brackish water perfectly well. I've seen nice Mexican-theme tanks using water worn cobbles, a mix of silver and coral sand for the substrate, and some Vallisneria at one end; you can see a nice set-up plan in "The Complete Aquarium" by Peter Scott, a biotope-plan book that you can pick up secondhand for pennies on Amazon. It's a great book, and I suspect you'll find it inspirational.>
I've found a book for sale on the subject, but it is very expensive, and the library doesn't stock it, so that's out - and the internet is failing me on this one. I'd like to be as authentic as I can be, but at this point, I'm completely at a loss, and hoping you can point me in the right direction? What substrate? What plants? What on earth does a Molly's habitat LOOK like!!?
<You name it! There are Mollies that live in caves, and feral Mollies found in the seas around Thailand, so really, it's all about your imagination.>
I thank you most sincerely for any information or advice you are able to share, as always!
- Jes
<Hope this helps, Neale.>

What is this fish/disease?  9/4/11
I was wondering if you would be able to identify this fish for me? I think it may be a long fin white skirt but if it is, something is wrong and I don't what and couldn't find anything. I have 3 of them and they all look
identical. They came with a tank I recently bought.
<These appear to be albino Black Widow or White Skirt Tetras, Gymnocorymbus ternetzi, and they do not seem to be suffering from any disease. They're just very odd looking! This species is a notorious fin-nipper when bored, and if you have just 3 specimens, do be careful they don't harass any slow-moving or long-finned fish kept with them -- Angels, Guppies, Gouramis, etc. Cheers, Neale.>

Skirt tetra aren't schooling; clown loach look malnourished  4/10/11
So I have a 50gal tank with a group of 5 skirts.
<Well, here's one problem: most fish won't school until there's at least 6 specimens, and often 8-10 is the best number to start with, especially in a medium-sized aquarium like yours.>
The aquarium is planted and has cave and has gravel/ aquarium sand combination. The skirts seem to be hanging out on there own not schooling.
<To be fair, this species is fairly bold and if just a few are kept, they often do their own thing most of the time, ignoring one another. The flip side though is that if there aren't enough of them, Black Skirt Tetras (Gymnocorymbus ternetzi) are confirmed fin-nippers. They aren't nearly as bad as Serpae Tetras or even Tiger Barbs, but they do sometimes nip the fins of slow-moving tankmates like Angels and Gouramis.>
The other fish in my aquarium are fine like my tiger barbs are schooling and rainbow fish are too. And my cats are doing there own thing. So why do u think the skirts are not schooling? The own big change recently in my aquarium is taking out all my plastic plants and swapping them out with real ones, and adding a co2 filter. This change happened 3 weeks ago. They stopped schooling 5 days ago.
<Curious.>
My second question is that my two clown loaches are malnourished and not eating.
<Unfortunately very common.>
Last week my clown loaches were schooling with my tiger barbs. This week they stopped and started to hide. They have always been small so I never suspected anything. Today I noticed one died and the other 2 were almost skin and bone. When I caught them they were real slow. So I moved them in my 20gal tank that is used for my babies and it is planted. I did this so they didn't have to compete for food and I could watch them eat. I threw in a couple bottom feeder tablets and more flakes than usual in that tank.
They are usually outgoing when feeding time hits and get all the flakes. So why are acting this way?
<Clown Loaches are prone to both intestinal worms and various microbial parasites, and the use of both the antimicrobial Metronidazole (Flagyl) and a dewormer such as Levamisole or Praziquantel is highly recommended. These are safe with Clown Loaches. In the US, you may be able to obtain these from your pet store; elsewhere you'll need to get them from a vet. Cheers, Neale.>

Male Guppy and Glofish... and Blk skirts... Incomp. stkg.    1/18/10
Hello! I recently bought a male guppy, a female guppy, two black tetras,
<Gymnocorymbus ternetzi? These are not compatible with Guppies; will nip them. Also, need to be kept in groups of 6+ specimens.>
and a tiger barb.
<Again, groups of 6 or more essential, otherwise they become very aggressive and nippy, especially once sexually mature.>
Before I purchased these, I had two African dwarf frogs, a pink Glofish, and a snail. I was wondering why my male guppy will not leave my pink Glofish alone and if there is anything I can do to keep him from chasing it and how I can get him to mate with my female guppy since I am interested in raising the fry?
<Your mistake here is to keep your fish in the wrong numbers. Schooling fish should be kept in groups. That means 6 of each, at least. The schooling fish are the Danios, the Tetras, and the Barbs. Guppies should be kept in groups of at least two females per male. If you insist on keeping these fish in groups for which their psychological programming is not set up for, then you're going to have problems. End of story.>
I tried using the search engine and it gave the stuff that I read before and it didn't give me any help. Thanks!!
~Kierstyn
<Do please read on the needs of your fish BEFORE you buy them. Doing what you're doing and buying "one of each" like candies isn't going to work. It is cruel to the fish and it creates problems for your. Cheers, Neale.> 
Re: Male Guppy and Glofish
All of the fish seem fine
<"Seem" is the operative word here.>
and I haven't had any problems with the rest of the except for the male guppy and the Glofish. So, do I need to buy more of each fish
<Assuming your tank is big enough, yes. You could keep 6 Black Widows and 6 Tiger Barbs in a 20-30 gallon tank without problems. Do bear in mind both species gets fairly big when mature, about 5 cm/2 inches, so these ARE NOT species for 10 gallon tanks!>
or do I need to get rid of certain ones?
<If the tank isn't big enough, this may be necessary too. I'd certainly get shot of both the Tiger Barbs and the Black Widow Tetras if you plan on keeping Fancy Guppies. Both those species are notorious fin-nippers, and sooner or later they'll have a go at the male Fancy Guppies. In fact, Fancy Guppies are honestly best kept in a tank of their own, possibly with species that stick to the bottom of the tank, like Corydoras catfish (again, a schooling species).>
This is new to me and I was in the pet store talking to one of the guys that takes care of the fish there and he said that they would all get along.
<Well, if this "expert" told you one barb and one tetra would be happy, he isn't an expert on anything to do with fish. Do always remember guys in the pet store range from long-time hobbyists through to teenagers working Saturdays. So be wise to that fact, and double-check anything you hear with something in a book. There are plenty of super aquarium books for newcomers to the hobby, one of the best of which (in my opinion) is "A Practical Guide to Setting Up Your Tropical Freshwater Aquarium". For under $10 it's an easy to read and very practical guide that'll help save you money in the long term. In the meantime, peruse these three articles:
http://www.wetwebmedia.com/ca/volume_5/volume_5_3/stocking.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwlivestk.htm
http://www.wetwebmedia.com/FWSubWebIndex/fwlvstksel.htm
These'll give you some idea about how much space fish need, which ones are least likely to cause problems, and how you can craft a community tank that looks like a habitat rather than just a box filled with fish.>
I appreciate all of your help!
<Happy to help. Cheers, Neale>

Re: Corydoras eggs  11/22/09
Dear Neale / Crew,
<Hello again Rose,>
If you don't mind my sharing, I'd like to report on my Cory fry for others like myself that can't find much in the way of beginner stories.
<By all means, share away.>
So, continuing from my other posts, when I moved the small Corys from the breeder net and into the larger tank I counted 74, and this was 40 days since the 120 eggs were first discovered. The filter intakes were covered with pantyhose so they wouldn't get sucked up and they all seemed to be active and finding their food.
<Cool.>
Despite daily partial water changes, the next couple days I found a few dead (various sizes, not just runts) and there must have been many more dead eaten by their peers in the next days as there now seems to be only thirty-some (of varying sizes) that seem to be holding steady.
<This does happen. Breeders wanting lots of juveniles tend to keep the fry in a big tank with no substrate. In standard community tanks, the substrate at the bottom of the tank is enough to harbour bacteria that seem lethal to small fry. For casual aquarists, this is no big deal, since the fun is simply raising a few fry, rather than hundreds. But if you're serious and want to sell the fry, then a tank where you can siphon out dirt from the bottom pane of glass daily seems to be important.>
Back in the original main tank, 40 days after they had the first eggs, the adult Corys had more eggs (over 170) that stayed on the wall for five days until I assume they hatched and were eaten. I guess the parents and the Blackskirts didn't have a taste for eggs?
<Maybe.>
On a side note, today one of the plump Blackskirts has been in a homemade cocohut all day and I have never seen them go in there (the huts are for the Corys). The fish's body looks normal, but I do wonder what it is doing (I assume NOT laying eggs as I have read that they scatter them carelessly).
<Blackskirt tetras (Gymnocorymbus ternetzi) are not the most peaceful tetras in the hobby, and in insufficient numbers can become nippy and waspish. Observe for a few days, and see if this fish is being bullied by its peers, or conversely, is behaving aggressively itself.>
Thank you, Rose
<Cheers, Neale.>

Re: Corydoras eggs -- 11/22/09
Dear Neale,
<Hello again Rose,>
Thank you for the response today in the dailies.
<My pleasure.>
I should have mentioned that the tank I moved the Cory fry into IS bare bottom for now, because I thought it would be easy for me to spot any dead as they would disappear over the beige sand that I use.
<Very good.>
I didn't know about the potential for substrate to harbor bacteria that could hurt them.
<Seems to be the case. The flip side is that a tank with lots of algae and Protozoans also contains lots of food that newly-hatched fish can eat.
That's what baby fish would eat in the wild. I recently bred some gobies while I was on the other side of the world, simply because the eggs hatched in a tank filled with algae, and the baby gobies found enough to eat.
Indeed, with livebearers, this is the best approach to take. But for whatever reason, Corydoras do seem very sensitive to microbes at the bottom of the tank.>
There are still more than a quarter from the eggs surviving at 56 days in and I take comfort in believing they would fare much worse than that in the wild.
<Heavens, you're doing much better than the wild! One of my marine biology instructors discussed Herrings, which have to spawn within a two-week period of time they can't accurately predict. Too early, there's no zooplankton for the Herring fry to eat; too late, and the population of algae in the plankton are so high they produce toxins that kill the baby fish. Some years no fry will survive, despite the female Herrings producing hundreds of thousands of eggs that season!>
I had mentioned a Blackskirt in the other tank that is hiding in a cocohut.
It is still there after at least 27 hours and has missed feedings.
<Odd. It might be ill, especially given its still not eating. Any other symptoms? Does it look swollen? Are its colours different to the others?
Are its fins raggedy?>
It is one of seven and none of the others are larger (I think it has reached full size).
<A good number... they should be happy.>
When they charge and nip they have always seemed to do so evenly and they are darker than many photos of their kind (even over beige sand).
<As is their wont. These are "boisterous" fish by any standards. If there's space, adding 2-3 more might help if the issue is social. But I'm not sure that it is.>
I'm surprised they don't nip at the Cory Cats as the Cats nearly blunder into them.
<Interesting. Corydoras are always nipped when I mix them with South American Puffers.>
Thank you, Rose
<Cheers, Neale.>

Corydoras Eggs, feuding Blackskirts -- 11/22/09
Dear Neale,
<Rose,>
Sorry to bother you again, but wanted to say the Blackskirt finally came out of the cocohut and was being chased behind the heater and all over the place.
<By the other Blackskirt tetras? Does sound social, in which case adding more can help. But if they're picking on a weak or sick specimen -- as sometimes happens -- this might not work. You could try moving it to another tank. By itself it might swim about more readily, and if you're lucky, it won't be nippy.>
When the juvenile Cory Cats grow larger I was going to move some of them in with their parents and these Blackskirts so there was already going to be some fish shuffling going on. I am wondering now if I will have to so some dividing and reintroducing of these Blackskirts as I guess the odd fish out would not be happy kept all alone either, correct?
<It isn't ideal, but it is what I'd do.>
Thank you, Rose
<Cheers, Neale.>

Black Skirt Tetra Infection? Help! 2/29/08 Hi, I have a 75 gallon well-established planted aquarium. The water parameters are good and all the fish have been healthy for about 5 years now. Today I noticed that a black-skirt tetra is ill. It is swimming abnormally - it's tail keeps falling and it makes brief jolts forward to right himself. It looks stressed and on closer inspection, it's torso area behind the operculum is red and swollen. I will try to catch him and put him in a quarantine tank tomorrow (not so easy in a planted aquarium) but what is wrong with him? An infection? What is the best way to treat him? Are the other fish in danger? Any help is appreciated. Thanks in advance. Kim <Hello Kim. Difficult to say precisely what's happening here, but it is certainly possible it has a bacterial infection of some sort. I'd try something like Maracyn and see how things go. Do remember to remove carbon from the filter, if you're using it. There are some parasitic infections that cause the gills to inflame, most notably Velvet, so do check for that (typically an off-white powder on the body). But parasites don't normally get into tanks unless you've added new fish. A photo might help pin things down. Cheers, Neale.>

Black Tetra, hlth.    12/5/07 Hello, In my mothers aquarium is a Black Tetra that has a small black growth below his lower lip, he is listless and has a very faint red hue on it's body every where except in the center. The fins are not red that I can see. He has not eaten in a week that I have seen and he has a little bit of a clear feces. I put in some furan 2 for 2 days, <... for what purpose?> did a water change and added some more for 2 days and I see no improvement. Can you help me. Thanks for any advice. thanks Sherri <Could you send along a photo? I suspect this may be a genetic issue... Many Gymnocorymbus have such difficulties nowadays... Do you have other individuals of this species? What other livestock is present? What re your water quality tests? Bob Fenner>

Question about Mollies & Tetras  9/7/07 Hello, <Ave,> I have a 30 gal. tank with only 6 fish in it. There is a Blackskirt tetra, a silver sail fin molly, a Plecostomus and two Platies. <Not a good selection. The Blackskirt tetra (by which I assume you mean Gymnocorymbus ternetzi) is [a] a schooling fish and [b] a notorious fin-nipper given that wild fish feed partially on the scales and fins of slow-moving fish. Plecs (in your case, likely Pterygoplichthys sp. rather than Hypostomus sp.) are massive fish that easily reach 45 cm in captivity and consequently need an aquarium around twice the size of yours to be kept safely. Finally, mollies are just plain easier to keep in brackish water, which your other fish don't want.> All of them are male, I think, but I had two females (one a platy and one a molly) that I had to give to a friend because they were constantly breeding. <Absolutely no way you can sex the tetra or the catfish.> Recently, the silver molly started chasing the tetra around the tank, getting in front of him and displaying his upper fin in his face, kind of like a screen. <Mollies are aggressive, and in the wild, adult males dominate patches of water, driving off other, weaker males and monopolising access to the females in the area. In short, yours is doing what comes natural. It is entirely normal for them to chase other species. I've seen this myself between mollies and Rainbowfish, for example.> It's gotten so bad that the tetra doesn't seem to want to eat. So, I went to PetSmart and asked what to do. They told me to add another Blackskirt tetra because the molly is displaying his 'dominance' as the tank king. <Garbage advice. As a rule of thumb, anything quoted by a big-chain pet store is more likely to be wrong than right. They tend to employ casual rather than expert staff, don't train them beyond selling and customer service, and have no investment in anything other than you coming back to buy more fish. There are exceptions I'm sure, but on the average if the person you talked to looks like a student working a Saturday job, best avoid.> So, I added a new tetra, and now the molly is going crazy chasing both!!!! <Quelle surprise.> What should I do? <Up to you. If it was me, I'd decide on what sort of aquarium I wanted. Do you want a school (i.e., 6) Blackskirt tetras? Do you want a school (i.e., 6) Platies. Do you want to keep mollies? The catfish has to go, I'm afraid, keeping it would be wrong. Me, I like mollies, and I'd go buy 2-3 more females to go with the male. I'd then convert the tank to a brackish system by adding a small amount of marine aquarium salt mix (not aquarium or tonic salt) with each water change (3-5 grammes per litre will do). I'd then add some gobies or flounders to the bottom of the tank. The mollies will ignore these completely, and they'd make for a fun, quirky aquarium. You could keep the Platies in this tank, too, as they do fine in slightly brackish water. The tetras, though, would have to be removed.> I really do not want to add any females because I do not have that much room for the fry. And the last time they were breeding, I had to isolate all the fry (because I didn't want them to be eaten!) and it was just a huge mess! <Just let them get eaten then. If you kept a couple of knight gobies (Stigmatogobius spp.) believe me, they'd get eaten! Otherwise, remember that you can always sell on young fish. That's what I do. If you have lots of real/plastic plants in the aquarium, at least some baby fish will survive. Having a separate tank to rear them in works well, and means that you cut down costs on things like food by trading in baby fish each time you visit the pet store.> Any advice would really be appreciated! Thank you, Crystal <Cheers, Neale>

Re: Question about Mollies & Tetras  9/7/07 Hello Neale, <Hello Crystal,> Thank you so much for your reply! I really appreciate it. The two tetras are sticking together and it seems that molly is leaving them alone, he displays his fin once in a while, but it seems the two tetras are ignoring it more and the older guy ate last night! :) <Very good.> I plan on getting a larger tank, I have been saving up for one, so I could keep the baby Plec ( a friend told me they grow fast) the one I'm looking at is a 50 to 60 gal, do you think that might work? <Sounds great.> I plan to keep the smaller tank in another part of the house, do you think I can convert it for a brackish system? I was wondering what other fish normally get along with mollies (+they would have to live in the brackish system) and is it okay to keep them all male too? <Converting to a low-end brackish tank would be easy. Lots of fish would work well here with the mollies -- bumblebee gobies, glassfish, wrestling halfbeaks, knight gobies, crazy fish, orange Chromides, flatfish... Have a read around the Brackish section here at WWM and see what's small and tickles your fancy. A brackish tank isn't any more difficult to run than a freshwater one, and in some ways easier because the marine salt mix tends to make disease less of an issue and buffers against water chemistry changes. You only need to add 3-5 grammes of salt mix per litre of water, so it isn't expensive, either.> And what other fish get along with the tetras, since I plan to get more of a variety of color for the larger tank. <Blackskirt tetras are best mixed with tetras, barbs, and Rainbowfish in the middle of the tank as well as active bottom dwellers like catfish and loaches. The things to avoid is anything slow or with long, trailing fins. Bettas, angels, fancy guppies, gouramis, etc would all be bad choices. So it's really not difficult to mix them with other fish, you just need to be a little more picky than normal.> Your advice is much appreciated, the only pet store near me is a PetSmart and I do agree-it seems like I'm constantly buying something there and they never really answer my questions! <I'm sure they mean well, but a store is a store, and largely interested in making a sale. My grandfather used to say about doctors that they had no vested interest in making you healthy, since healthy people don't need doctors. They just didn't want you to die because then they lost a customer! A lot of pet stores are run the same way... so long as you keep coming back to buy replacement fish and new bottles of medication, they're happy.> Thank you, Crystal <Good luck, Neale>

Black lumps on tetra body and fins  8/23/07 Please, can you help me diagnose my tetras? <We'll see> I have looked everywhere and can't find anything to match the appearance of these fish. Something that came close during my research was "lip fibroma", most common in angelfish and other "kissing" fish. 2 of my tetra (now in quarantine for 4 weeks) have lumpy growths first on their lips, then appearing on their fins and tail bases. It's spreading for sure. Both fish are eating and lively, but obviously something is very wrong with their bodies. The lumps are raised, and grey/black in color. I hope the photos I took help. (Image links:) http://i23.photobucket.com/albums/b360/Meechity/fishy1.jpg http://i23.photobucket.com/albums/b360/Meechity/fishy2.jpg http://i23.photobucket.com/albums/b360/Meechity/fishy3.jpg Your site is invaluable. I would not bother to write you if I hadn't searched all I could elsewhere. Thank you so much :) ~M <Does appear tumorous... Perhaps there is a bacterial or protozoan involvement here... I would try one course/treatment with Metronidazole/Flagyl AND feeding of antibiotic (the "usual" broad-spectrum, gram-negative varieties commercially available) like Thera-A as attempts at cure.... otherwise, careful isolation... euthanization. Bob Fenner>

Black Skirt tetras, nippy beh.   8/8/07 Hello, Yesterday I did a water change and added 4 new fish to my 20 gal. tank, an algae eater and three red spot phantom tetras. This morning I noticed my four black skirt tetras frantically chasing each other, they haven't stopped for hours. I only have 13 fish in the tank, not over crowded, and have had the black skirt tetras for over a year and they have always been fine. The water temp. is about 82 deg. and the rest of the stats fall into acceptable parameters. Do you know what could have triggered the sudden change in the tetras' behavior? Jon <Hello Jon. Black skirt tetras -- Gymnocorymbus ternetzi -- is probably in the top 5, if not the top 3 fin-nippers in the freshwater aquarium hobby. They should always be kept in groups of 6 or more specimens; any less, and the behaviour you describe is almost inevitable. Some people may have experiences to the contrary, but they are in the minority. As a rule, these are fish that should only be kept with fast moving tetras and barbs, and NEVER mixed with angels or gouramis, because these poor fish get nipped mercilessly. Why have they just started? Perhaps they have reached a certain age and have become sexually mature? Who knows. But the simple answer is that what you have described is not in the least unusual, and no, there isn't a cure, beyond adding a few more specimens so that aggression is diffused out a bit more evenly. The "chasing" seems to be about hierarchical positioning in the school; the bigger the group, the more quickly they settle down. Pretty normal schooling fish behaviour, and you'll see something like this with danios, barbs, all sorts of schooling fish. Hope this helps, Neale>

Breeding Black Skirt Tetras -- 06/11/07 I recently lost my 6" Jurupari and my Tiger Barb. This morning I awoke to find my puffer had jumped out of the tank last night sometime. The last two fish I have in my tank are two black tetras that I have had for years - about a week ago I noticed the larger tetras belly was getting bigger - It seemed to be eating fine, but after losing so many fish at once I was really concerned it might be a parasite. It doesn't have a protruding scale issue, so I don't think its dropsy, anyway today as I am watching them, the two Tetras are acting really strange... The small Tetra will not leave the big Tetras side, its as if they are dancing together and the one with the big belly keeps spitting up a round ball - lots of them. I have no idea what is going on please help! I know my tank's cycle is off right now, but is it infested with something or what? Beth < Sounds like a typical tetra spawning. The female is the larger fish and the male is fertilizing the eggs as she is scattering them about. I guess the other fish were intimidating them. Now that they are gone they are off spawning scattering their eggs everywhere.-Chuck> Re: Two Black Tetras, Breeding Tetras -- 06/11/07 WOW! Really! What can I do to raise the fry? It is all in my main tank too, do I take the adults out? And what do I feed the fry? Thanks! <Most tetras are egg scatters. They swim side by side. As she lays the eggs he fertilizes them as they swim along. The eggs and fry will be eaten by the adults. You can remove the adults and you may see little fry swimming around the tank. They need to be fed very small live food for about a week or so. In a large tank many fry will starve because the food is so sparse in the tank. Commercially they set up pairs in a 10 gallon tank filled with a couple inches of marbles over the bottom. After the pair spawn they are removed. The eggs fall between the pores between the marbles so they won't be eaten. After a couple of days the marbles are removed. The eggs hatch and the fry are fed green water full of infusoria or paramecium. In a week of so they are fed baby brine shrimp and microworms. They fry will be very tiny and hard to see so look closely. Chances are a few will survive if the eggs hatch.-Chuck>

My Tetra's mouth has moved   3/11/07 I have a 10 gal tank with 3 black skirt tetras 1 white skirt and an Otocinclus. The white skirt is the oldest member and her mouth seems to have moved from the point of her face up her face toward the top of her head. The bottom Jaw flesh seems to have gotten bigger and the top lip receded so that it looks like she cannot really close her mouth totally. I suspected maybe mouth rot, but there is no white fuzz on her. <Mmm... much more likely "something" developmental (like acromegaly in humans) or resultant from an injury (jumping...)> I had one other white skirt go this way until he started swimming on his side in vertical circles and doing stupid stuff so I euthanized him. Any ideas what I am dealing with? Could it just be an old age issue? <Yes> Her right eye seems to have eye pop also, but her left one is okay. I have been changing the water weekly, but the water temp is a little high due to treatment for suspected ich. <Mmm, not likely too high... can tolerate temperatures into the low nineties F.> Any suggestions would be appreciated. Thanks <What is your water quality overall? Hardness, pH... do you have appreciable nitrate? Bob Fenner>

Re: My Tetra's mouth has moved (follow-up)  - 3/12/07 <<Hello. Tom covering for Bob this time.>> Water quality:  Nitrites 0, ammonia 0. Don't have hardness or nitrate tester. But this may be an issue, my pH reads 7.6 but this is the max the tester will register so it may be higher. Could this be the issue? <<Not 'the' issue, as such, but could definitely be 'an' issue, as you suggest. A high pH level isn't the problem it was once seen to be as long as it remains stable. Fish acclimate to pH ranges outside of the 'ideal' quite readily, for the most part, and the consensus is that it's better to keep our fish in water that's readily available from the tap rather than 'toying' with it where pH is concerned. Bob's reference to water hardness was meant to get a sense of the buffering capability of your water, i.e. the ability of the water to resist changes in pH. The higher the buffering capacity, the less likely you will experience a dangerous, potentially catastrophic, drop in pH. To address your question more specifically, White Skirt Tetras have a pretty wide pH-tolerance range with the high end being around 8.5. There aren't many fish in the freshwater arena that 'prefer' pH levels this high even among the Cichlids, which are known for thriving in alkaline water.>> How do I lower it on a permanent basis?   <<Rather than saying you can't, I'd prefer to tell you not to try. First, it may be totally unnecessary and, second, you may be setting yourself up for problems. The saltwater folks have a leg up on most of us FW hobbyists as there are substrate materials, aragonite in particular, that constantly provide calcium carbonate (among other trace elements) to the water, raising pH to levels their aquariums require on what might be deemed a 'permanent' basis. Lowering pH is more problematic and, unfortunately, temporary over the long haul. Just not a good idea with play with it.>> I will try to get the other testers but we live in a small community and may not be able to quickly. <<As you've probably surmised, I don't think this is necessarily an urgent matter but I agree that it's one that should be looked into soon. You need to have a feel for the buffering capacity of your water to ensure there are no sudden plunges in your pH levels. If there's an issue here, this is it in my opinion. My best to you. Tom>>

Pregnant Blackskirt? I have a Blackskirt tetra. I have had her for almost a year and her tummy has become quite enlarged.  I noticed also she is reddish under her back fin.  Could she be pregnant or sick? <Could be either or neither... this species does get quite round... from over-eating as well as egg maturation> That is assuming it's a girl.  I have two other Blackskirts with it, a yellow gourami, 5 danios, 4 tiger barbs, 2 albino barbs, 1 clown loach, and 4 rose barbs  located in at least a 40 gal tank.  I treated the tank for gut worms a month ago.  What could it be? Sincerely Melissa Lee <Might even be just resultant from the treatment... I encourage you to feed your fishes a type of food that has a laxative effect... like brine shrimp or Daphnia... once a day for a few weeks. If your Black Skirt is "full of eggs" it may release them (they will be consumed by the other fishes unless you place it, the other Black Skirts in another system). Bob Fenner>

Black Skirt Tetras I have a 50 Gal. Freshwater I have had 3 black skirt tetra in the tank for about 5 months. They have started to turn gray because of age. The larger one lost half of its back fin about 6 days ago don't know why it also has a large belly. Why the large belly? Also just noticed one had a large black bump on its side. Can't figure that out any ideas? <Hard to tell without a picture, maybe pregnant, maybe sick, the bump could be a tumor or something similar.> Also one last Question I bought 3 smaller ones yesterday they all got along fine yesterday. But today the smaller ones are constantly like picking on the older ones mostly the bigger one with the big belly. They chase him all over the tank mostly up by his head. Any idea why they are doing this? <They could just be trying to establish dominance, or if the older one with the large belly is sick, they may be picking on him because he is weak.> I took the new ones out and put them in a breeder basket <I would test my water to make sure the parameters are good, and maybe add some more decorations the tank to provide hiding places for the fish that are being picked on.  If you add the new fish back into the tank the beatings should stop in time.  Best Regards, Gage>

my fish (Tetra color change) Hi My name is Krystal and I want to know about black skirts I have notice that their fins change colors. Why? <Black Skirt Tetras fins do become clear to glassy with age, growth... this is their genetic disposition... that is, their natural development. Perhaps by having part of their bodies transparent, it makes them harder for predators to detect. Bob Fenner>

Sick black skirt tetra I have had a group of 5 black skirt tetras in my 37 gallon community for about 6 months. One of my tetras has developed some sort of growth (tumor maybe?) on it's tail. the tail itself is completely intact, but there is a growth, a couple mm in diameter, that is red with white spots and protrudes about 1 mm from each side of the fin. I am very confused about this as I have seen quite a few common fish diseases, and this seems to match none of them. At this time I have isolated the fish in a 2 gallon tank and am feeding antibacterial food. Do you have any ideas as to what this growth might be? <Good description. This may well be a tumor of some sort... could be a "worm" parasite like one of the many trematodes of fishes... other possibilities of internal parasite groups... My best guess, perhaps a Lernaeid (crustacean) called "anchorworm"... You might try "teasing" the area with a sharp forceps, needle with the fish underwater, light low, in a net... to see if the mass can be easily removed... then topically treat the area with a daub ("Q-tip") of antiseptic (the mercury-based ones for humans: mercurochrome, merthiolate, merbromin... will do). Bob Fenner> Thank you, Ariel

Sexing Gymnocorymbus To Bob F Hi Bob it's me Louis again.  I wanted to know how to tell the gender between a white skirt tetra, if you can try to show a picture other websites make no sense. <At size, maturity, females are much larger, shinier... males darker, smaller with longer un-paired fins. Please read here: http://www.wetwebmedia.com/FWSubWebIndex/tetragonopfaqs1.htm  and search WWM, the Net under the names: Black Skirt Tetra, Gymnocorymbus ternetzi. Bob Fenner>

What this? Blackskirt The nice man at the pet shop told me this was a "Blue Widow", but it seems that he was the only person on the planet that knows this species by that name.  He also seemed to think s/he was a great addition to my tank set up - but needless to say I'm beginning to doubt his word. What is it?  S/he's no more than an inch and a half long, and flat like a Silver Dollar - and an awful lot prettier that my crummy picture suggests! <Actually a very nice pic... of a xanthic variety of a Black Skirt Tetra, Gymnocorymbus ternetzi... you can look these names up on the Net, Fishbase.org, WetWebMedia.com... a very nice aquarium species.> Superb website, by the way.  An unbelievable wealth of information. Melinda <Thank you for being part of it. Bob Fenner>

Black Widow Tetra Hello, <Greetings> Maybe you can help, <Will most certainly try!> We have a 55 gal tank with a few fish, among them we have 4 black widow tetras, one of them is getting "fat", so just in case we isolated the fish in a plastic floating tank designed so the eggs fall in the bottom and cannot be eaten. <I would venture the guess that this fish is just getting fat and is not actually pregnant. I have about 30 of these fish and certain ones remain fat all the time while others are fairly slim looking.> Here is the question, I read a lot of stuff about how long it takes the eggs to hatch, but what we want to know, is how long we have to wait for the female to lay the eggs? Or should we let her go w/the other fish, and if so, will they eat the eggs? <I would go ahead and let her back into the main tank. If you don't have plants in there, maybe add a few so that if she is going to lay eggs she has a place to do so.> Thank you for your help. Patricia <You're welcome. Ronni>

Black Skirt Tetras I have a 50 Gal. Freshwater I have had 3 black skirt tetra in the tank for about 5 months. They have started to turn gray because of age. The larger one lost half of its back fin about 6 days ago don't know why it also has a large belly. Why the large belly? Also just noticed one had a large black bump on its side. Can't figure that out any ideas? <Hard to tell without a picture, maybe pregnant, maybe sick, the bump could be a tumor or something similar.> Also one last Question I bought 3 smaller ones yesterday they all got along fine yesterday. But today the smaller ones are constantly like picking on the older ones mostly the bigger one with the big belly. They chase him all over the tank mostly up by his head. Any idea why they are doing this? <They could just be trying to establish dominance, or if the older one with the large belly is sick, they may be picking on him because he is weak.> I took the new ones out and put them in a breeder basket <I would test my water to make sure the parameters are good, and maybe add some more decorations the tank to provide hiding places for the fish that are being picked on.  If you add the new fish back into the tank the beatings should stop in time.  Best Regards, Gage>

School's In Session Long story. I have a 5gal tank, for lack of expenses, though I have heard that 20gal is better. Last week, out of compassion or whatever, I tried to save some goldfish some people on my college campus were not treating right. Oops. Found out later that they are not good starter fish. Well they all died within a few days. I had not given the tank enough time to cycle. I was told that I could get a couple fish to put in here for starters. Three days ago I got one Serpae tetra and one black skirt tetra. The man at the pet shop said they were his favorites to use. Later that day, I found out online about the schooling fish, and that they need to be in groups of six minimum. What do I do? They seem healthy so far, active. <Well, I would give your tank a little more time to finish cycling, then you might want to add maybe two more of each. Not exactly a school, but small groups> I realized yesterday that I was overfeeding, so I have cut back to once a day, smaller pinch. Water is clear, but there is a smell, reminds me of urine. No other way to put it... Here are my questions. is the smell something bad? how do I get rid of it? <Well, if it smells like urine, it may not be a good thing. A healthy tank has an "earthy", pleasant smell, not an ammonia-like smell. What kind of filter are you using? If you are not already (and assuming your filter can accommodate it), try using some activated carbon. That will help remove discoloration and odor. And, of course, in a small tank, you should be diligent about regular water changes! Acquire some test kits: ammonia, nitrite, nitrate. By regular water testing, particularly in the early stages of your tank's existence, you can really get a handle for what's going on.> Would the two groups work good together, or do I need eventually to get a separate tank? <I think that they will work with diligent attention to maintenance, but you will eventually have to get a larger tank to accommodate these fish at full size. Maybe neon tetras would be a better choice for the long run?> To add fish, how big a tank do I need for a good number? <Maybe a 10 or 20 gallon tank. This would give you more flexibility> Don't have the gages yet, but will be getting them soon. Any help will be so appreciated. Thanks for everything. I've been reading and it's good info. Amy <Keep reading and learning! You're doing great! Scott F.>

My fish (Tetra color change) Hi My name is Krystal and I want to know about black skirts I have notice that their fins change colors. Why? <Black Skirt Tetras fins do become clear to glassy with age, growth... this is their genetic disposition... that is, their natural development. Perhaps by having part of their bodies transparent, it makes them harder for predators to detect. Bob Fenner>

Sick black skirt tetra I have had a group of 5 black skirt tetras in my 37 gallon community for about 6 months. One of my tetras has developed some sort of growth (tumor maybe?) on it's tail. the tail itself is completely intact, but there is a growth, a couple mm in diameter, that is red with white spots and protrudes about 1 mm from each side of the fin. I am very confused about this as I have seen quite a few common fish diseases, and this seems to match none of them. At this time I have isolated the fish in a 2 gallon tank and am feeding antibacterial food. Do you have any ideas as to what this growth might be? <Good description. This may well be a tumor of some sort... could be a "worm" parasite like one of the many Trematodes of fishes... other possibilities of internal parasite groups... My best guess, perhaps a Lernaeid (crustacean) called "Anchorworm"... You might try "teasing" the area with a sharp forceps, needle with the fish underwater, light low, in a net... to see if the mass can be easily removed... then topically treat the area with a daub ("Q-tip") of antiseptic (the mercury-based ones for humans: mercurochrome, Merthiolate, Merbromin... will do). Bob Fenner> Thank you, Ariel

Pregnant Blackskirt? I have a Blackskirt tetra. I have had her for almost a year and her tummy has become quite enlarged.  I noticed also she is reddish under her back fin.  Could she be pregnant or sick? <Could be either or neither... this species does get quite round... from over-eating as well as egg maturation> That is assuming it's a girl.  I have two other Blackskirts with it, a yellow Gourami, 5 Danios, 4 tiger barbs, 2 albino barbs, 1 clown loach, and 4 rose barbs  located in at least a 40 gal tank.  I treated the tank for gut worms a month ago.  What could it be? Sincerely Melissa Lee <Might even be just resultant from the treatment... I encourage you to feed your fishes a type of food that has a laxative effect... like brine shrimp or Daphnia... once a day for a few weeks. If your Black Skirt is "full of eggs" it may release them (they will be consumed by the other fishes unless you place it, the other Black Skirts in another system). Bob Fenner>

Pregnant/fat black widows  - Bob's Response Hey... just came across this site by chance, LUCK! Hoping you could help.... 3 of 5 black widow tetras have huge bellies.. the other two are smaller in size.. they all seem to have slight blood streaked abdominals...do you think this is due to the shark chasing them a lot (maybe hurting them)... <Maybe> ...or that they are having little tetras of their own?? <Doubtful> If they are pregnant, then how can I tell when they are ready to burst? Last time my guppy had babies... she went crazy on her own, so I felt bad and put her back in with the other... and the poor little babies only lived for 2 hours.  Thank you....thank you, thank you , Debbie  <Please read through the freshwater site: http://www.wetwebmedia.com/FWSubWebIndex/fwsubwebindex.htm re tetras, feeding... Bob Fenner> 

Freshwater fish identifications, ChuckR Hi there I need to identify two fish to find out more about them. The one was called a "black widow" in the shop I bought it from. Its shape is very similar to a silver dollar. It is mostly black on the top half of its body and the tail is silver. Apprx 2cm long. I've looked everywhere for information on this fish but can not get anything, except black widow tetra, which I do not think it is. (saw a picture somewhere) < The black skirt tetra is sometimes called the black widow tetra. If this is not your fish then you will need to provide more info like a photo.> The other fish is definitely a goby, no doubt about that. It is white with black spots, and a small black "stripe" at the back of its top fin. The sizes are apprx 3 & 5cm each. The shop owner said its a spotted goby and that the female is the bigger one of the two, but alas, I can find no information/pictures on what it actually is. It is a very shay fish. <Look at photos of the knight goby (Stigmatogobius sadanundio ). Males have longer fins.> Both are freshwater fish. I've got two male guppies in the tank and sometime during today, the one lost half of its tail fin. I doubt that it will be the "black widow" because they've been sharing a tank for 2 months now. < The gobies are capable of biting the tail of smaller fish thinking that they are food.-Chuck> Any help would be greatly appreciated. Thanking you in anticipation. Jaco Ps. If it is a stupid question or I can find the info somewhere else, please tell me so.

Freshwater fish identifications, BobF Hi there I need to identify two fish to find out more about them. The one was called a "black widow" in the shop I bought it from. Its shape is very similar to a silver dollar. It is mostly black on the top half of its body and the tail is silver. Apprx 2cm long. I've looked everywhere for information on this fish but can not get anything, except black widow tetra, which I do not think it is. (saw a picture somewhere) <Likely a Black Skirt Tetra... there are varieties, differences within this species: http://freshaquarium.about.com/cs/characins2/a/blackwidow.htm> The other fish is definitely a goby, no doubt about that. It is white with black spots, and a small black "stripe" at the back of its top fin. The sizes are apprx 3 & 5 cm each. The shop owner said its a spotted goby and that the female is the bigger one of the two, but alas, I can find no information/pictures on what it actually is. It is a very shy fish. <Maybe a knight goby: http://www.wetwebmedia.com/BrackishSubWebIndex/bracgobioids.htm> Both are freshwater fish. I've got two male guppies in the tank and sometime during today, the one lost half of its tail fin. <Could be from either of the above> I doubt that it will be the "black widow" because they've been sharing a tank for 2 months now. Any help would be greatly appreciated. Thanking you in anticipation. Jaco Ps. If it is a stupid question or I can find the info somewhere else, please tell me so. <Be chatting, Bob Fenner who encourages you to investigate before you buy livestock>

Black Skirt Tetra Issue Hi. I'm new to having fish and need help. I set up my tank at the beginning of October (30 gallon). I have 3 Black Skirt Tetra, 3 Zebra Danios, and 1 algae eater (sorry I don't know his real name - it starts with a P). <Pleco works> Earlier today one of the tetra died. I had noticed some erratic behavior and sluggish swimming over the last day or so.  He also looked as though he had bubbles on him. When I removed him from the water the bubbles were white spots, particularly on his tail. The other two tetras are now acting oddly, they are not schooling, both are staying near the top, which is odd for them, they normally swim near the bottom. What do I do? I did a water change about 2 weeks ago - the fish had been overfed while we were out of town on vacation and the tank was covered with algae. This is when I added my algae eater. All has been well until the last 24 hours or so. HELP!   Thank you, Allison <The white spots are a pretty sure sign of Ich. Treat with salt. Read here for it's proper use. http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=32 You should also be doing more water changes. Use a gravel vac to remove the old food and fish waste. This is very important when treating for Ich. Don>

Re: Black Skirt Tetra Issue Thank you for your response!  Today the white spots look more like fluffy stuff - on the tail and fins.  It almost appears to be fungal.    Thanks for any help you can offer. Allison <Please read here: http://www.wetwebmedia.com/FWSubWebIndex/fwinfectdisfaqs.htm Bob Fenner>

Tetras with sores Hi there, I have several black high skirt tetras of different ages.  The problem is as they get older and larger, 2 of them developed a sore around their mouths. <Sores around the mouth are often times due to mouth fungus.  Which is a treatable disease, I have found that medicines from the Mardel company have worked exceptionally well.> The largest one died and I am worried this will continue until I find the problem.  They share the tank with red serapes and a 5-6 inch Pleco. <There doesn't seem to be any sort of tank mates that would be nipping or bothering the Black Skirts.> Any suggestions would be great. <Make sure that the filtration is good on your tank, keep up on the water changes.  This will help keep the fish's immune system working well, and it will also offer a better environment so that fungus and bacteria won't be able to thrive.  It's best for you to set up a quarantine tank, so in the case that your fish do come down with more sores around their mouth then you will be able to remove them from the tank and medicate them.  Look at medicines like Maracyn, and even a broader based medicine like Maracide from Mardel for a good treatment for the problem.> <Good Luck. -Magnus>

Become a Sponsor
Featured Sponsors: