15 Fin-tastic Facts About The Black Tetra For Kids

Black tetra facts and information are educational!

Black tetra (Gymnocorymbus ternetzi), also sometimes referred to as the petticoat tetra, black widow tetra, blackamoor, black skirt tetra, and high-fin black skirt tetra, are a unique addition to community aquariums. Unlike other colorful species of the Characidae family, they have more of a darker appearance.

Black tetra has the iconic tetragonal shape with a significantly tall front and shrinks at the end of the body towards the tail. Black skirt tetras are the origin of South America and are vastly available in Argentina, Paraguay, Brazil, and Bolivia.

Black tetras belong to the family of Characidae, who are famous for being colorful and bright. But these fish are darker in appearance compared to the others and stand out extremely beautiful in a well-maintained aquarium.

If you liked these true facts about black tetras, then you'll surely like these facts about cuttlefish and garfish too!

Black Tetra

Fact File

What do they prey on?

Worms, Small Crustaceans, Insects

What do they eat?


Average litter size?


How much do they weigh?


How long are they?

3 in (7.6 cm)

How tall are they?


What do they look like?

Gray, Silver

Skin Type


What are their main threats?

Large Fish, Eels, Invertebrates

What is their conservation status?

Not Extinct

Where you'll find them

Rivers, Lakes


South America





Scientific Name

Gymnocorymbus ternetzi





Black Tetra Interesting Facts

What type of animal is a black tetra?

The black tetra (Gymnocorymbus ternetzi) is a fish in the Animalia kingdom, belonging to the family of Characidae. Black skirt tetras are freshwater fish, they come from Southern America ranging from Brazil, Argentina, Paraguay, and Bolivia. Black phantom tetra male's fin is black, so is the dorsal fin of a female, females have a reddish colored pelvis, adipose, and anal fin. Long-fin black tetra fish is slightly bigger than black tetra with bigger black fins. The Black neon tetra has an expanded body compared to others, with two distinct colored stripes, white and black.

What class of animal does a black tetra belong to?

Black skirt tetra belongs to the class of Actinopterygii, they are ray-finned fish. Actinopterygii is divided into two different classes, Cladistia and Actinopteri. Actinopterygians comprise almost 30,000 species of fish, including piranha and other species.

How many black tetras are there in the world?

Unfortunately, there is no accurate count on the population of black skirt tetras. As these species are easily available and are bred in private aquariums, it is impossible to know the exact population.

Where does a black tetra live?

Black skirt tetras are freshwater fish of the Characidae family. Black tetra wild origin of the Paraguay River flowing through Paraguay, Brazil, and Northeastern Argentina. Most of these species are bred in captivity, and new hybrids are developed and bred separately. The ones which we can easily find in pet stores are all bred in captivity. The tank size for long skirt tetra black should be of minimum 15 gallons (56.8 l), as they are energetic swimmers and need lots of space to swim around.

What is a black tetra's habitat?

Black widow tetra can easily adapt to any range of conditions, habituated to large plants in their surroundings. These species prefer acidic and soft water and they can match the water conditions. The upper Paraguay basin, Bolivia, and Brazil are the origins of the phantom black tetra.

A black morpho tetra inhabits shallow and warm waters covered with leaf piles and lots of fallen branches.

Who do black tetras live with?

A black skirt tetra (gymnocorymbus ternetzi) is, by nature, a schooling fish, it is found in a group of six or more. Because of their peaceful nature, they can adjust along with all other species. They have been found fin nipping fishes that move slowly or long-finned fishes.

How long does a black tetra live?

A fully grown black tetra's lifespan can be between three and five years, but with proper care and diet, these species can live longer in aquariums. Just as other species of fish, a black tetra's lifespan can be affected by the level of care and diet they receive. Black emperor tetra males are pointed shade and slightly larger than females.

How do they reproduce?

A male black skirt tetra claims a territory that will guard against others during the period of depositing the eggs period. These species reach their sexual maturity at the age of two years old, a pregnant black tetra spawning at intervals spreading the eggs in several places laying almost 1,000 eggs. After the female lays eggs the male will fertilize the eggs externally.

Their eggs will hatch in 24-36 hours, the young fry will initially feed on their egg sac. Cannibalism of eggs is extremely common in this species and if they are breeding in captivity it should be made sure to take both the males and females out of the breeding tank as they might eat the eggs.

What is their conservation status?

These species are globally recognized as a quality addition to the aquarium school. These species are mostly bred in captivity. The IUCN Red List has listed these species as Not Extinct.

Black Tetra Fun Facts

What do black tetras look like?

These beautiful fish can be found in South America.

Black tetras are easily recognizable because of their black anal and dorsal fins, and two or three vertical black stripes on the body of silvery gray color. The front of their bodies is taller compared to the back, they are pretty small in size growing up to a total length of 3 in (7.6 cm).

Female black tetras are larger than males with rounder bodies, and their anal fin is aligned with the upstanding black stripes on the abdomen. The male black skirt tetra is smaller and more slanderous than females with larger dorsal and anal fins compared to females. As they are fish, black tetras do not have legs.

How cute are they?

Black tetras are friendly creatures that tend to live peacefully among tank mates are cute to the core! Black tetra fish are active swimmers and need sufficient aquarium space. With the tetragonal shape, translucent face, and tail, they attract many breeders to be kept as pets.

How do they communicate?

All fish have otoliths consisting of a sensory epithelium made up of calcareous otoliths and their hair cells that they use to communicate with each other.

How big is a black tetra?

Black widow tetras are relatively small in nature and reach an adult size of 2 in (5 cm). Hybrids, like the long-finned tetras, are bigger in size due to cross-breeding.

How fast can a black tetra swim?

Black tetras are schooling fish that swim in groups, moving delicately and quickly around the fish tank. These species are super fast swimmers, they reach quickly towards food compared to their other tank mates.

How much does a black tetra weigh?

Unfortunately, no data is available about the weight of black tetra fish. These species can grow only up to 3 in (7.6 cm) and are relatively smaller fish in an aquarium.

What are the male and female names of their species?

Black tetra belongs to the family of Characidae. However, different names for males and females of the species are not given. Females and males can easily be differentiated by looking at the anal fins, as the males will have wider anal fins compared to the females.

What would you call a baby black tetra?

Unfortunately, a juvenile black tetra has not been given a specific name, it is, however, known as fry, just like all other species of baby fish.

What do they eat?

Black tetra feeding habits allow them to eat anything and they have a wide range of diets, they are not choosy when it comes to food. This species will feed on the plants in the wild and gobble almost any insect they will come across.

Black widow tetra accepts all the foods provided to them like live foods, worms, vegetables, and high-quality flake foods.

These species gather near the surface of the water and use plants to hide as they prey on insects, small worms, and crustaceans and no, they do not feed on other fish!

Are they aggressive?

Black skirt tetras are fearful creatures that are known to hiding in caves, plants, woods, and under the rocks instead of facing their predators. They are aggressive predators, though! They have sometimes been seen fin nipping other small fishes that move slow or long-finned fishes. This species should always be kept in a group of six or more so that they can focus on them instead of other tank mates.

Though these species are sometimes called after the poisonous spider, black widow tetra fish are not poisonous at all. Black tetra fish behavior might become aggressive based on the number of fish in the range of their school.

Would they make a good pet?

Yes, black skirt tetras will make an excellent pet as they can easily become accustomed to any environment, and it is easy to create an artificial habit for them. Not much of an experience is required for keeping them as pets. Black skirt tetras are active swimmers, and they need a large tank, the size should be at least 15 gallons (56.8 l) for them to swim around. While breeding we should always take the males and females out of the breeding tanks, for the safety of the eggs as cannibalism of eggs is common among these species and might eat the eggs.

Black skirt tetras are freshwater fish, so the aquarium should have a proper flow of running water. Black tetra fish are conventional species in the aquarium trade, these species are easily available in pet stores because of their vast popularity and ease to raise in captivity.

Long-finned black tetra is hybrid species of black tetra with no natural habitat, these species were developed in Europe having no wild population as they are bred in captivity.

Tips and tricks for taking care of black tetra as a pet.

Step 1: These species need a larger aquarium of at least 15 gallons (56.8 l), as they love to spend their time swimming.

Step 2: A black tetra fish tank needs dark sands or gravel for the bottom to make it similar to its natural habitat. They live in a school of six or more.

Step 3: Place rocks, artificial caves, and driftwoods for them to hide.

Step 4: Place taller plants as these species lay eggs on the bottom of the aquariums, and rarely visit the bottom.

Step 5: Though these species can get accustomed to all conditions but to keep them healthy and make them live longer we need to maintain proper water conditions which are favorable for them.

Step 6: Provide them with a good diet that consists of high-quality live foods and flack foods.

Did you know...

Black tetra care is extremely easy as it is extremely rare for them to grow more than 3 in (7.6 cm).

Black tetra tank size should be large enough as they mostly gather near the surface and it is extremely rare for them to visit the bottoms.

Black tetra teeth are minute and sharply placed in a row, they are aggressive predators and will eat anything that fits their mouth.

Black tetra territorial behavior can be seen when they feel threatened and also found nipping long-finned fish.

Black tetra white tail diseases are a common occurrence for their premature death.

There is little known about the emerald black tetra, even though they are one of the tetra color variations.

Red and black tetra fish are also called blood tetra because of their red coloration with a flat and tall body. A unique black comma-shaped spot is visible just behind the gills.

When these fishes lay eggs, you should make sure to take out the adult tetras from the breeding tank and use the spawning mops to gather the eggs. Young fry will hatch within 24-36 hours.

Black tetra freshwater fish species are found nipping long-finned fishes and are best suited for community tanks.

What other fish are in the same family as the black tetra?

Black skirted tetra belongs to the family of Characidae along with others including piranha, Buenos Aires tetra, bloodfin, neon tetra, cave tetra, and many others, these species are known to be popular among the school aquarium fish.  They are all freshwater species that belong to the tropical and subtropical regions. The smallest species in the family of Characidae known as Hyphessobrycon roseus can grow only 0.7 in (1.8 cm) to its maximum length. Many species of Characidae belong to river areas, such as the blind cave tetra, and piranhas also fall into the same family as black tetras.

What changes to black tetras as they grow up?

As the black skirt tetra achieves the maturity size after one year of birth, its color slowly starts to fade from dark to grayish-silver coloration. As they keep growing they lose their color and become pale. These species also have a lighter skin color than normal because of fear and sickness.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! For more relatable content, check out these black neon tetra facts and congo tetra facts for kids.

You can even occupy yourself at home by coloring in one of our free printable black tetra coloring pages.



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