Black Skirt Tetra (Gymnocorymbus ternetzi) is a fresh water omnivore of the Characidae family, native to Paraguay and Guapore Rivers of southern Brazil, Argentina, and Bolivia.
This fish is recognized quite easily by two vertical black stripes on the front half of the body and black dorsal and anal fins (the latter can be quite long in some varieties).
Once they reach their maturity at approximately one year, their dark coloration slowly begins to fade, leading to very pale colors by the age of 5.
They can reach up to 2 inches total length and live 3-5 years.
Table of Contents
Tank size suitable for black skirt tetras
To keep a small school of Black Skirt Tetras, you will need at least a 15-gallon tank no less than 20 inches long due to the fact that they are very active swimmers.
For the best simulation of its natural habitat, use darker river gravel as substrate with some dried leaves on top of it to accomplish the natural brown color reflection in the water, though leaves should be replaced every few weeks.
The aquarium should be planted with big plants, though not too densely, because these fish prefer some open space for swimming.
Also add a piece of driftwood, snags, and twisted roots; however, make sure all aquarium elements are prewashed in a salt bath.
If you want your Black Skirt Tetras to thrive and reach their full potential in coloration, keep the light subdued.
When it comes to water quality, filtration and maintaining cleanliness of the water by replacing 25-50% of its amount every other week is critical to ensure all potentially harmful substances, like ammonia and nitrates, are kept away from the tank.
As is the case of most tetras, they prefer soft water (up to 30 ppm, but the softer, the better) and slightly acidic with a pH ranging from 6.8-7.0 and KH from 4.0-8.0.
As far as water temperature is concerned, the fish can endure anything from 60-90° Fahrenheit, but will do best at 70-85° Fahrenheit.
Feeding Black Skirt Tetra
In its natural habitat, tetras feed on worms, small invertebrates, and insects.
Occasionally, they will eat small amounts of algae and plants.
These particular tetras are not fastidious at all, so in aquarium conditions they will eat almost anything you offer.
The best diet regime though would consist of flake foods on a daily basis and only the amount they can eat within about 5 minutes.
Occasional feedings of live and frozen foods and/or vegetables will round out their diet.
Among the variety of live food, their favorite is mosquito larvae, daphnia, and brine shrimp, while frozen food includes bloodworms, blackworms, and again, daphnia and brine shrimp.
Breeding Black Skirt Tetra
Before the breeding process commences, an aquarist should be able to tell the difference between the males and the females.
This can be a little tricky, but if you focus your attention on the individual body and disregard the fins, you will notice the males are usually a bit smaller and more elongated than the females, which are plump and deeper in comparison to the length of the males.
At the breeding stage, these differences are even more noticeable, since the females look as they are on the point of exploding.
Black Skirt Tetra is a free spawning (egg scattering) fish and shows no parental care.
Nevertheless, it is bred relatively easily if a few rules are followed.
The first thing you should do is set up a separate spawning aquarium where the males and the females are to be introduced at a later point; this will also be the place for the fry to develop in the early stages.
The size of the breeding tank should be 10 to 20-gallons depending on how many pairs you are willing to breed at the same time.
Water inside should be virgin, but mature and heavily aerated the moment the pairs are transferred.
The water temperature is recommended to be a few degrees higher than the original basic aquarium.
At the bottom of the tank you should lay some kind of mesh, grass-like mat, layer of glass marble, raised plastic grate, or the like in order to create a surface that will let the eggs fall through, but small enough holes as to not let the adults reach and eat them, after the breeding is over.
There should also be plants, or synthetic clumps of spawning mops, as places for eggs to be scattered and attached to.
All the elements inside should be prewashed in salt bath to kill all the pests or snails eager to eat the eggs once they are laid.
Seven to ten days before the breeding starts, pairs should be separated from the rest of the school and from each other and fed heavily on live and frozen foods three times a day.
By the time they begin to look more brightly colored and females considerably fat, you should start introducing the females one night before the males.
At that point, the males start to chase the females, which is when you need to begin observing them carefully.
If any sign of overaggressive behavior by the males is visible or if the female rejects or attacks the male, they must be removed to a separate or divided tank.
You can let them try again only after another week of preparations.
If spawning goes well, the female will scatter up to an incredible 1,000 eggs all over the plants and the bottom of the tank.
Once the eggs are laid and milt released, remove both male and female fish from the spawning tank to prevent them from eating the eggs.
Within 24-36 hours the eggs will begin to hatch.
Tank mates & Safety measures
Black Skirt Tetras are semi-aggressive fin-nipping species, especially towards fish with long fins like bettas or angelfish.
Smaller and less active tetras like Cardinal Tetras, Black Neon Tetras, and Neon Tetras, peaceful bottom dwelling fish, danios, rasboras, and some dwarf cichlids are ideal tank mates for the Black Skirt Tetra.
Although it is not recommended to keep Black Skirt Tetras with other aggressive fish such as bettas and tiger barbs, many experienced fish keepers confirm that adding a few more Black Skirt Tetras in your aquarium, they focus more on each other, consequently showing almost no aggression towards another species in the tank.
As with most fish, Black Skirt Tetras are very skilled jumpers so it is advisable to keep your tank covered to prevent them from jumping out of the aquarium.
Still, the number one priority should be keeping your water quality at an adequate level to avoid this action.