Overview
The Black Skirt Tetra (Gymnocorymbus ternetzi) is a beginner freshwater species known for its silver, black coloration. Also called black widow tetra. Mid.
Origin & Appearance
Origin: South America.
Colors: Silver, Black.
Body Shape: Fusiform (torpedo/streamlined). Typical adult dimensions: 7.5 x 1.3 x 2.2.
Sexual Dimorphism: Subtle; males have broader anal fin.
Tank & Water Requirements
| Min Tank Size | 20 gallons |
| Temperature | 68–79°F |
| pH Range | 6–7.5 |
| Water Hardness (GH) | 5-15 |
| Bioload | low |
| Oxygen Demand | low |
| Plant Safe | yes |
| Aquarium Position | Mid |
Behavior & Activity
Mid-water swimmer; slightly jerky movement; can be nippy with fin-flaring chases; moderate schooling cohesion
Speed: 42/100Aggression: 3/10diurnalSchooling (6+)
Breeding
Moderate; egg scatterer
Common Diseases
💊 Ich💊 fin rot
Expert Notes
Also called black widow tetra
Compatible Tank Mates
✓ neon tetra✓ corydoras catfish✓ bristlenose pleco✓ harlequin rasbora✓ cherry barb✓ kuhli loach✓ dwarf gourami✓ mystery snail