Animal-World > Aquarium Tropical Fish > Characins > Blackskirt Tetra

Blackskirt Tetra

Black Tetra ~ Black Widow

Family: CharacidaeGymnocorymbus ternetziPhoto © Animal-World: Courtesy David Brough

   First introduced into the United States in the 1930's, the Blackskirt Tetra is one of the most popular aquarium fish!

   The Blackskirt Tetra, also known as the Black Tetra or Black Widow, is a good fish for the beginner as it is very hardy, undemanding, and easily bred. It is a real beauty in a community aquarium. It is very active and fast moving though it can tend towards fin nipping. Because of this they should not be kept with smaller fishes, but will do very well in a community tank with larger fishes.

   Being a schooling fish the Blackskirt will appreciate the company of its own kind. How many fish make a school?... the standard answer is 7. They also like a well lit tank with dense areas of bunched low vegetation which will leave lots of open areas to swim in. They are hardy at 70° F to 90° F, but are prone to develop ich if kept in colder temperatures.

Various strains of the Blackskirt Tetra have also been developed:

• A long-finned variety, the Blackskirt Hifin Tetra, was first developed in Europe. It is also very popular and is readily available. These fish are a bit more difficult to breed than the Blackskirt Tetra, probably because of their being highly inbred already. They are also referred to as the Longfin Blackskirt Tetra, Long-fin Black Widow or Longfinned Black Tetra.
• Strains in a natural white, pink, and blue have also been developed. Of these the White Tetra or Goldenskirt Tetra has become very common followed by the Colored Skirt Tetra. It is sometimes artificially dyed in various pastels colors and sold as a Colored Tetra or under various colored names such as the Blueberry Tetra, Strawberry Tetra, or Rainbow Tetra.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Freshwater Aquarium

Geographic Distribution Gymnocorymbus ternetzi Data provided by FishBase.org Scientific Classification Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Characiformes Family: Characidae

Habitat: Distribution / Background

   The BlackSkirt Tetra, also known as the Black Tetra or Black Widow, was described by Boulenger in 1895. They are found in South America in Paraguay and Guapore Basins where they inhabit the upper layers of the water feeding on worms, small crustaceans and insects. Many are captive bred for the aquarium industry.

• Scientific Name: Gymnocorymbus ternetzi
• Social Grouping: Groups
• IUCN Red List: NE - Not Evaluated or not listed

Description

   The Blackskirt Tetra is a deep-bodied species and laterally compressed. It is distinguished by two vertical stripes and by what appears to be overly developed dorsal and anal fins. These make it appear as if though it has a "skirt", with most of its mass on the bottom half of the body. The fine black color changes to a gray in the adult.

• Maximum Size: 2.3 inches (5.84 cm) - These fish get up to 2.3 inches (5.5 cm). Will breed at 1.5 inches.

Fish Keeping Difficulty

• Aquarium Hardiness: Very Hardy
• Aquarist Experience Level: Beginner

Foods and Feeding

   Since they are omnivorous the Blackskirt Tetra will generally eat all kinds of live, fresh, and flake foods. To keep a good balance give them a high quality flake food everyday. Feed brine shrimp (either live or frozen) or blood worms as a treat.

• Diet Type: Omnivore
• Flake Food: Yes
• Tablet Pellet: Yes
• Live foods (fishes, shrimps, worms): Some of Diet
• Vegetable Food: Some of Diet
• Meaty Food: Some of Diet
• Feeding Frequency: Several feedings per day

Aquarium Care

• Water Changes: Bi-weekly

Aquarium Setup

• Minimum Tank Size: 15 gal (57 L) - Fifteen gallons is the least amount of space advisable to host a small school.
• Substrate Type: Any
• Lighting Needs: Moderate - normal lighting
• Temperature: 70.0 - 79.0° F (21.1 - 26.1° C)
• Range ph: 5.8-8.5
• Hardness Range: 3 - 30 dGH
• Brackish: No
• Water Movement: Moderate
• Water Region: All

Social Behaviors

   They are active and can be semi-aggressive fin nippers. They should be kept in a community aquarium with fish the same size or larger. With age they become a more sedentary fish.

• Venomous: No
• Temperament: Semi-aggressive - Relative to other tetras, Black Skirts have a tendency to be slightly more aggressive and fin nippers are not uncommon among this species.
• Compatible with:
  • Same species - conspecifics: Yes
  • Peaceful fish (): Monitor - Watch for stress in other fish caused by Black Skirt fin nipping.
  • Semi-Aggressive: (): Threat
  • Shrimps, Crabs, Snails: Safe - not aggressive

Sex: Sexual differences

Photo Courtesy: Fish2U

   The male's dorsal fin is more narrowed and more pointed. Also, the male's frontal portion of the "skirt" or anal fin is noticeably broad while the female's "skirt" tends to run parallel to the stomach line. A mature female is also more plump.

Breeding / Reproduction

   The Black Tetra, Black Widow, or Blackskirt Tetra are egg layers. They are easily breed with a good pairing. The biggest challenge is that the young are prone to starving to death if they are in a dark tank and can't find a food source. The fry should have plenty of light, both day and night, until they are large enough to eat freshly hatched brine shrimp.    See the description of how to breed these fish in Breeding Freshwater Fish.

• Ease of Propagation: Easy

Availability

   The Blackskirt Tetra, also sold as the Black Tetra or Black Widow, is readily available.

References

Animal-World References
Freshwater Fish and Plants Tropical Fish ~ Freshwater Fish ~ Aquatic Plants

Authors: David Brough, CFS and Clarice Brough, CFS

• Skirt Tetra : $1.99
• Skirt Tetra : $3.99

Gymnocorymbus Ternetzi White Skirt Tetra Offered By: That Pet Place Price: $1.99

Skirt Tetra Offered By: PetsMart Price: $3.99

Lastest Comments on Blackskirt Tetra View all 33 comments on Blackskirt Tetra Add Your Comment

Ray - 2012-01-22 My black skirt tetra has been alive for 12 years, what a miracle fish. Reply

Jason Wicklund - 2012-01-08 Hey I have a 20 gallon with 5 black skirt tetras, 1 shubunkin goldfish, two bumble bee platies, 1 Bala Shark, 2 plecos, 1 guppy, 1 Cichlid, and 3 tiger barbs. My fish are very good together. The only problem I have is that My tetras aren't eating and I've only had them a day... Is that normal for them not to eat the first couple days? Click For Replies (1) David Brough - 2012-01-22 I would say it is not normal unless they are uncomfortable for some reason. Check the temperature and do partial water changes if there is any presence of ammonia or nitrites until the biological filter is functioning. Reply

Jason Wicklund - 2012-01-08 Hey I have a 20 gallon with 5 black skirt tetras, 1 Reply

Katie - 2009-11-27 I have two black-skirt tetras in a ten gallon tank. These fish were kept with three danios (two long finned), two ghost shrimp, an ADF, and one chinese alge eater. These tetras DO NOT like long-finned fish. It nipped at my betta's tail when he was in the tank, and had recently killed one of my danios, I give the other one till the morning... his fin has been nipped at and is frayed from the ends. The small finned danio is fine. Also the chinese alge eater loves them. They are great fish to keep, i just suggest that you try not to add new fish, nor put them with long-tailed fish. Click For Replies (2) Skeith - 2010-06-24 Well if your danios are slow, they will be attacked. I've researched a lot of fish and the Black Tetra will nip at slow moving fish and acts aggressively towards them. Be careful. Anonymous - 2011-12-29 Add a compatible tropical fish. Add in even numbers. Not in odd!! Reply

gixxerk5 - 2010-06-26 Are they supposed to change colors? One minute their lower fin will be black and the next clear it's kinda cool and sometimes their stripes disappear. Click For Replies (2) nm123 - 2011-11-03 Out of my understanding they will lose only the black skirt. I have heard. I never heard of them losing there stripes this is probably a cause of stress. Did yours lose its stripes yet? plz write me back asap Alex Burleson - 2011-11-04 It's normal for fish of all species to appear to 'change colors'. They can, in fact, however this could be due to reflection and other factors. Reply

Lachele Tyson - 2010-02-02 What is the yellow stuff at the bottom the the tank in the gravel. Can they live in distilled water. Does fish places sell both male and female. how fast do you need to change the water when it turns gray. Click For Replies (1) Donovin Cumming-Smith - 2011-09-23 It is good to start with purified water or even boiled water that has cooled down. There are easier methods though, you can grab a bottle of anti-chlorine at the pet store which will prepare the water quite nicely. Unfortunately that is only the start! Lol it takes sometime to get the water ready for you fish though due to the biological processes of the bacteria that need to take place in the water, for your tank to support a healthy and well balanced environment for your fish. The gray in your tank is a good thing that means the bacteria are changing the ammonia which is harmful to the fish, please note you do get the bacteria ready in a bottle for your tank just follow the instructions. Be careful read up and do a lot of research about fish and the conditions they need to survive before you purchase any fish. Find out about fin nippers because they can cause problems with larger fined fish. One last thing find out about how many fish to get at a time because the conditions in your tank need to adjust for the amount of life and find out how to properly condition you fish for less stress when adding them to your tank, because less stress equals healthier fish. Reply

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