Breeding Black Skirt Tetra
Breeding Gymnocorymbus ternetzi: a readily-bred egg-scattering tetra. Sexing, separate conditioning, a warm acidic spawning tank, fast-hatching eggs and infusoria first foods.
Overview
The Black Skirt Tetra (Gymnocorymbus ternetzi), also known as the Black Widow Tetra, is an egg-scattering tetra that is quite easily bred, although a separate breeding tank is needed to save the fry. The KB record rates breeding difficulty as beginner-level.
Sexing
Males are smaller and slimmer than females and have more pointed dorsal and anal fins. Females become noticeably fuller-bodied when carrying eggs.
Conditioning
For pair spawning, condition males and females separately on high-quality live and frozen foods at around 24-26 °C (75-78 °F). Group spawning is also possible using about half a dozen specimens of each sex.
Breeding Setup
Use a dimly-lit breeding tank with fine-leaved plants, java moss or spawning mops, or a mesh base allowing eggs to fall through out of the adults' reach. For pair spawning, transfer the fattest female and best-coloured male to a tank set several degrees warmer than the conditioning tank, at 28-30 °C (82-86 °F), with an acidic pH.
- Spawning temperature: 28-30 °C (82-86 °F)
- pH: acidic side of neutral
- Medium: fine-leaved plants, java moss, mops or mesh base
- Lighting: dim (eggs and fry are light-sensitive)
Spawning Behavior & Trigger
The raised temperature in the spawning tank acts as the trigger; a conditioned pair should spawn the following morning, scattering eggs among the plants or through the mesh.
Egg & Fry Care
Adults will consume the eggs if given the opportunity, so remove them immediately once spawning is detected. Eggs hatch in 18-36 hours, with the fry becoming free-swimming a few days later. Offer infusoria as a first food, then microworm or brine shrimp nauplii. Keep the tank dimly lit, as the eggs and fry are light-sensitive.
Common Challenges
Egg predation by the adults and light sensitivity of eggs and fry are the main issues to manage.