The black skirt tetra’s scientific name is Gymnocorymbus ternetzi.
All tetras belong to the family Characidae more commonly know as Characid. This family includes 776 species in 152 different genera ranging from Southwest Texas to Argentina.  Black skirts are also commonly referred to as black tetras or black widow tetras.

The black skirt can be recognized by its characteristic black “skirt”. There is also an albino version or white skirt tetra that is commonly available commercially. These are variations that occur naturally in the wild. White Skirt tetras are often dipped in pastel colors and marketed as fruit tetras. This dying process is counterproductive to the fish’s health. They are much more prone toward illness and have a greatly reduced life span. White skirt tetras have also been made to change color by being fed dyed foods. These tetras are generally healthy and will revert to their natural pigmentation once they start ingesting unaltered food.

 Black skirts display their strongest coloration when young. As the fish grows older, the black skirt tetra will become duller and fade to a silvery gray. They have an average life expectancy of around five years.

Black skirt tetras are relatively small fish. They  will reach their adult size of about 2.5 inches at about one year of age. You do not need a particularly large aquarium to keep them. Any desktop nano tank is large enough to house an entire family of them. They are also the perfect candidates for wall mounted aquariums. Nano systems have redefined the world of aquarium keeping in recent years. They don’t take up much space and they make great accent pieces for any work space or home décor.

Tetras have a docile nature. They function well in community fish tanks as long as none of the other members of the community are overly aggressive. The tetras species are shoaling fish. They swim in groups. Therefore it is a good idea to add multiple tetras to your community tank. Four to six is ideal.

The black skirt tetra is indigenous to South America. They inhabit subtropical river basins in Bolivia, Brazil and northern Argentina where water temperatures stay between 68 and 79° F. Like most fish that originate from South America, they are accustomed to soft, slightly acidic water. Aquarium water can be filtered through peat. Or water softener can be added to the water. Products such as Tetra's Black Water Extract can be purchased at most fish specialty stores. This extract closely approximates the conditions of Amazon River water in your fish tank.
Because they are a smaller variety of fish native to predatory waters, the black skirts are hiders by nature. They take readily to heavily planted environments. Black skirts are prone to swimming in the middle layer of your aquarium.

Black skirt tetras are omnivores in their natural habitat. In captivity they are not picky when it comes to what they eat. Any tropical fish flakes will do just fine. Tetras have a tendency to be fin nippers. Caution should be used when housing them with fish that have long, flowing fins such as angelfish, bettas or  fancy tailed guppies, especially in a  well established group of tetras. Keeping your tetras well fed will reduce the likelihood of their instinctual behavior becoming problematic.

They are egg laying fish. They tend to scatter their eggs to increase the likelihood of survival. It is difficult to distinguish the difference between males and females unless the female is carrying eggs. In the spawning cycle the female’s body tends to be a little rounder than the males. After spawning, adult fish should be removed to prevent them from eating their eggs.

The eggs will hatch in about 24 hours. Black skirt fry are very tiny when they first hatch. The fry can be fed commercial liquid fry foods when newly hatched. When they get a little bigger their diet can be changed to powdered fry food or newly hatched brine shrimp. Powdered egg is an acceptable substitute.