Black Tetra introduction
Just like many other tetras, the Black Tetra (Gymnocorymbus ternetzi) is a hardy and popular aquarium fish, particularly suitable for peaceful community aquariums. The Black Tetra is an active, schooling species and you should never get less than 6 Black Tetras, preferably more. Black Tetras can also form schools with other tetras. Getting Black Tetras to eat in captivity is certainly not hard and overfeeding is unfortunately quite common, especially among beginner aquarists. Obesity can make breeding Black Tetra trickier and is unhealthy for the fish.
The Black Tetra hails from the Paraguay and Guaporé River basins and can reach a length of 6 cm in the wild. It can adapt to pH-levels between 6.0 and 8.0 and a water hardiness from dH 5 to 20. Since the Black Tetra inhabits subtropical waters, the water temperature in the aquarium should be 20 – 26°C. If you want to start breeding Black Tetra, you can however increase the temperature somewhat. This species is also known as the Black Widow Tetra.
Sexing Black Tetras
Sexing Black Tetras can be tricky, because males and females look quite similar. The female does however display a rounder belly and normally grows bigger than the male. During the breeding period, both sexes tend to darken their color. Black Tetras kept in a suitable environment and given nutritious food will also display darker colors than other Black Tetras.
If you want to breed Black Tetras, the best method is to keep a school together and let them form their own pairs. This way, you do not have to try sexing them. After all, this is a schooling species, and keeping them in pairs is never really a good idea.
Gymnocorymbus ternetzi. Picture added to article by AC Tropical fish.
Breeding Black Tetras
Getting Black Tetras to spawn is not difficult, the tricky part is to keep eggs and fry from being eaten by adult fish. To get them to spawn, a planted 10-20 gallon aquarium is usually enough. Keep the water quality up, feed your fish nutritious food, and keep the water temperature around 26-27 degrees C. The pH-value should be around neutral and the water hardiness below dH 15 (the lower the better). Adding spawning grass to the bottom is appreciated but not mandatory.
As mentioned above, adult fish can eat eggs and fry and should therefore be removed from the aquarium. If your fish gets really stressed when you catch them, you can instead hang a large net or basket inside the aquarium and place the adult fish in it before they spawn. This way, the eggs will fall down through the mesh and rest safely at the bottom. This method is also a great alternative if you only have one aquarium.
Black Tetra eggs
The Black Tetra is an egg scattering species that produces large quantities of really small eggs. Unfertilized eggs will soon start to look fuzzy due to fungi growth and should be removed from the aquarium to prevent the fungi from attacking healthy, fertilized eggs. The eggs normally hatch within four days at 26 degrees C.
Caring for Black Tetra fry
Newly hatched Black Tetra fry are really minute and will spend most of their time clinging to walls and aquarium decoration. You can feed them liquid fry food, micro worms or vinegar eels. When they are around three days old, they will be large enough to eat newly hatched brine shrimp. One month old Black Tetra fry can be given the same food as their parents.
Large water changes are harmful to Black Tetra fry and you should therefore only change a small amount of water each time. Preferably carry out small water changes several times a day to keep the water quality up without casing any rapid changes.
Didn't find the info you were looking for? Register for free and ask your question in our Aquarium forum !
Our knowledgeable staff usually responds to any question within 24 hours
Keeping and breeding Astyanax bimaculatus
Black Phantom Tetra - Information about keeping and breeding Black Phantom Tetras in aquariums.
Black Skirt Tetra - Information about keeping and breeding Black Skirt Tetras in aquariums.
Bloodfin Tetra - Information about keeping and breeding Bloodfin Tetras in aquariums.
Cardinal Tetra Fish - An introduction to Cardinal teras - Paracheirodon axelrodi.
Cardinal Tetra - Information about all aspect of keeping and breeding Cardinal Tetras.
Congo tetra - An introduction to Congo tetra - Micralestes interruptus.
Glowlight Tetra - Information about keeping and breeding Glowlight Tetras in aquariums.
Lemon Tetra - Information about keeping and breeding Lemon Tetras in aquariums.
Neon Tetra Fish - An introduction to Neon tetras.
Neon Tetra - An indepth article about Neon Tetras, their breeding and the dreaded Neon Tetra Disease.
Serpae tetra - An introduction to the Serpae tetra.
Swordtail Characins - Corynopoma riisei. And how to breed them.