Black neon tetra (Hyphessobrycon herbertaxelrodi) is a freshwater fish native to southern Brazil. It belongs to the Characidae family of freshwater tropical and subtropical fish. Many people consider it a black variation of the regular neon tetra species, which is far from true. Though both are from the same tetra fish family, they belong to different genus. Other than the family, the only common thing between the two is perhaps the fact that both are popular aquarium species.
Black neon tetras attain a length of 4-5 cm at full growth. The females can be identified by their broad, rounded body, as opposed to the slender, slightly small body of males. Adding to their beauty are the two adjacent black and silver-white longitudinal stripes that run from their eye to tail. The black stripe is thicker than the white one. Their belly is silver in color, while the fins are colorless ... almost transparent. Their eyes are big and have a crimson red semicircle at the top.
You have to provide them a suitable environment so as to ensure that they feel comfortable. To create a habitat, you need a darkish tank with a capacity of at least 20 liters, or more. You can keep 4 - 6 black neon tetras in a fish tank as they love to live in groups. You should fill up the fish tank with soft water, which is acidic in nature and has a pH value in the range of 5.5 and 7.5. The temperature of the water should be in the range of 72º to 78º Fahrenheit. You can put lots of live plants along the boundary of the aquarium. There should be enough open water for the species to swim freely.
Basically, black neon tetra are omnivorous in nature and feed on a wide variety of foods. In their natural habitat, they prefer small invertebrates, like insects and their larvae, and live plants. In aquarium, on the other hand, you can give them flake foods and freeze dried foods to eat. You can also feed them live foods, like brine shrimp, blackworm, and frozen bloodworm, at times. Such foods should be given at least once in a week as they help them maintain their attractive colors. These fish typically eat all the food that is available in the top and middle layer of the water. They will never eat anything lying at the bottom of the tank.
Black neon tetras start breeding when they are a year old. For proper breeding, you should feed them plenty of live foods. It is advisable that the male and female are provided a separate tank with right environment, which is more or less similar to their natural habitat. You have to ensure the water of the breeding tank is very soft and acidic, and consists of enough plants in it. The aquarium should be placed in an area where it receives soft light. The female lays several hundreds eggs together, which get scattered all around. These eggs are quite sticky and cling to various surfaces inside the aquarium.
Soon after breeding, you should take the large fish out of the aquarium. Otherwise, they will eat up the eggs and babies. The eggs will hatch within a week and the tiny fry will start swimming all over the place. Once their yolk sac is gone, you can start feeding them fine foods. Ideally, the first food for the fry should be infusoria. You can also give them flakes that are in the form of tiny particles. As they grow, they can have some coarse food. Live foods are also good for fry.
The species usually has a lifespan of around 5 years. With proper care though, they can live for a few more years. Ideal tank mates for the species include neon tetra, black widow tetra, cardinal tetra, etc.