Black Skirt Tetra (Gymnocorymbus ternetzi) is a beginner-level freshwater fish that needs at least 20 gallons and 70-80°F. A hardy, active tetra that tolerates a wide range of conditions. Keep it in a group to reduce fin-nipping, and avoid pairing it with long-finned fish like bettas or angelfish.
Care facts at a glance
| Scientific name | Gymnocorymbus ternetzi |
|---|---|
| Family | Characidae |
| Origin | Paraguay and Parana basins, South America |
| Adult size | 2.5 in |
| Minimum tank | 20 gallons |
| Temperature | 70-80°F |
| pH | 6.0-7.5 |
| Temperament | Peaceful, may nip long fins |
| Social behavior | Schooling, keep 6+ |
| Swim level | Mid |
| Difficulty | Beginner |
| Diet | Omnivore: flakes, pellets, frozen foods |
| Typical lifespan | 3-5 years |
Quick tips
- A larger group spreads out any nipping.
- Skip slow, long-finned tankmates.
San Diego water
Captive-bred stock usually adapts to San Diego tap water with slow acclimation. For best color and health, many keepers blend tap with RO/DI water. Learn the numbers in our San Diego tap water guide.
Before you buy
Make sure your tank is cycled (how to cycle a tank), check your numbers with the water testing guide, and use the compatibility guide to check tankmates. These are general ranges; individual fish and local water vary.
Find it at Pet Zone
Pet Zone Tropical Fish is a San Diego aquarium store with two locations. Stock changes daily, so call ahead if you are after a specific species or plant. Shop online at petzonesd.com.
4160 Convoy St, San Diego, CA 92111
(858) 987-0309
Open daily, 10am-6pm
Aquascaping, planted tanks
4266 University Ave, San Diego, CA 92105
(619) 283-1812
Closed Monday; Tue-Fri 10:30am-6pm, Sat 11am-6pm, Sun 11am-4pm
Monster fish, koi