Thoughts on black skirt tetras

[Tl52505]

I want to heat peoples thoughts/opinions on black skirt tetras. Mine are god awful and are crazy. I started off with 9 but they killed eachother and now have 4. The always steal all of the food from other fish and kill anything in sight. Long story short, I don’t like them

 

[Byron]

This is perhaps somewhat extreme, but it is not unusual for the species and not surprising. There are other factors involved, though.

This species, Gymnocorymbus ternetzi, is somewhat aggressive by nature. It needs a good-sized group so the natural inherent aggressive traits play out naturally and hopefully without incident. Nine is not a bod number, but 12-15 might work better--but they might not. The species has a natural level of aggressive traits, but individual fish can be more or less so. Tank space is another factor, the smaller the tank the more it causes aggressive tendencies in any species of characin (or other shoaling fish). I would not keep this species in anything under 3 feet in length, and preferably 4-feet, in a group of 15-20. Given the issue here, I would see if you can rehome the four rather than acquiring 8-10 more especially since you don't like them.

Other fish species may or may not be pursued, that is always another risk. The stress of being confined in a tank with an aggressive species is severe, and you can lose other fish over time. Even if the tetras do not physically show this, they can be sending out the chemical signals (allomones) which are just as stressful to other species. And slow or long-fin fish must never be housed with this species.

 

[Oblio]

I have a school of 9 Black Skirt (Glofish) along with 6 Buenos Aries and 10 Corys with no issues. Every once in a while they get a little feisty but the tetras actually cross shoal a bit. This is however in a 6' 125 gal tank, so that may be a factor. I should add that it is usually the BA that get feisty.

 

[Fishmanic]

I have 4 black skirt tetras along with 4 tiger barbs in a 29 gallon tank. (I know I need larger schools which I once had but some died off.) The two species generally avoid each other and I've had no issues with them. I also have 2 BN plecos in the tank and they get along fine...each of them have their own territory and cave.
At one time I had 7 black skirt tetras in a 35 gallon tank and never had problems with injuries.

 

[DoubleDutch]

I've kept them for years without any issue.
The most main misses with this species :

Too small tank
Too small shoal
Misunderstanding of their behaviour (thinking their natural behaviour of chasing, showing of etc... are agression)

 

[GaryE]

Black skirt, white skirt, widow tetras have had a funny history in the hobby, They were common in the 70s here, rare in the 90s as they got a bad rep for nipping and fighting (plus the colours are nothing to write home about) and only made a comeback when they were used in gene splicing to create glo fish tetras. If I am going to get a nasty tetra, it'll at least be colourful.

The problem is that I have been in a few stores where this was the only tetra sold. There are dozens and dozens of better fish for the average person with an average sized tank to keep, but this one is cheap to buy from wholesalers.

If you like the, then @DoubleDutch has nailed the problem with them. They need large groups in large tanks.

 

[Slaphppy7]

I'd rather have black phantom tetras than black skirts...just as attractive (more so, IMO), and no nipping

Of course, like ALL tetras, they must be kept in adequate numbers for best/most natural behavior

 

[Stan510]

Its not brought up often enough that Tetras kill each other off. Like Tiger Barbs but more subtle with Tetras. Every group of six or so has top fish taking out the others slowly over time. I had big beautiful Bleeding Heart tets do that and then the final huge 2 year old died from some unknown disease.

 

[lottabubbles]

it must be the size of the tank those fish are in weather they are super aggressive or not. have 4 black skirted tetras and they act like they are a happy family. my tiger barbs get along also. they are swimming in a 125gal tank.

 

[GaryE]

I disagree on the slowly knocking each other off observation. That has not been my experience at all. I find that you lose tetras upon arrival, especially farm raised ones, but after the first month, you should be good for 5 years plus if you keep a proper eye on things. Two years old is a young tetra.

That doesn't apply to many high bodied, flat sided species, as they do scrap quite a bit. They can do damage. It brings me back to my endlessly repeated "don't generalize - every species is different'. A tall flat sided serpae will fight, a tall flat sided hatchet won't.

But murder most foul with cardinals, glowlights, neons, black neons etc? Nope.

 

[Slaphppy7]

they are swimming in a 125gal tank.

That is the key factor..in a tank that big, they may rarely even encounter each other

 

[lottabubbles]

That is the key factor..in a tank that big, they may rarely even encounter each other

normally that may be the case but the tiger barbs swim around all day long together. around 1:00pm every day they get together in one corner and go nose down at a 45deg angle and take a siesta for an hour. i don't know what that angle is all about.