Longfin Black Skirt Tetra Breeding Guide
Breeding the Longfin Black Skirt Tetra (Gymnocorymbus ternetzi): black skirt tetra spawning biology, with the long fins as a heritable selectively bred trait.
Overview
The Longfin Black Skirt Tetra is a selectively bred long-finned form of the Black Skirt Tetra, Gymnocorymbus ternetzi; its spawning biology is that of the standard black skirt tetra, an egg-scattering characid that gives no parental care. The elongated finnage is a heritable selectively bred trait, not a fixed feature, so it segregates among offspring.
Sexing
In the black skirt tetra, males are noticeably slimmer and a little smaller than females, and the male also has more pointed dorsal and anal fins than the female; the trailing fins of the long-fin form can make this harder to read.
Conditioning
Condition the sexes separately on plenty of live and frozen foods at around 24-26 C (75-78 F) before attempting to breed.
Breeding Setup
- Spawning tank around 18 x 12 x 12 inches (about 45 x 30 x 30 cm), dimly lit.
- Temperature raised to about 28-30 C (82-86 F), several degrees above the main tank.
- pH on the acidic side of neutral.
- Clumps of fine-leaved plants such as java moss or spawning mops, or a mesh base that lets eggs fall out of reach of the adults.
Spawning Behavior & Trigger
Spawning can occur in a group of about six males and six females or as a pair, which typically spawns the morning after transfer. Eggs are scattered among the plants or fall through the mesh, and the adults will eat the eggs, so they must be removed immediately on detection.
Egg & Fry Care
Eggs hatch in around 18-36 hours and the fry become free-swimming a few days later. Eggs and fry are light sensitive in the early stages and need dim lighting. Start the fry on an infusoria-type food, progressing to microworm and brine shrimp nauplii.
Common Challenges
Egg predation by adults and light sensitivity are the usual hurdles. Because the long fins are a heritable selectively bred trait, only a proportion of fry inherit the trait, and long-finned adults may be slower and more vulnerable to fin damage during spawning.