Sexed
The sexes of the African long-finned tetra are easy to distinguish. For me the most obvious difference is in the dorsal fin. In males it is longer and pointed while in females it is shorter and rounded. Males grow slightly larger than females and the body of males tends to be deeper than that of females. The anal fin of the male tends to be convex and with white edges, while that of the female to be straight or concave.
Breeding in the wild
Some observations suggest that, in the wild, an African school of long-finned tetra can reproduce for an extended period, laying a few eggs each day on the plants. It is reasonable to assume that this versatile fish has several different breeding strategies in the wild adapted to the wide range of habitats in which it lives.
Raising in an aquarium
The African Long-finned Tetra can be raised as a school or in pairs. This is not an easy tetra to breed, but people who make a serious attempt can be successful. Parents must be very well conditioned to foods rich in protein. The water in the rearing tank should be soft and acidic. Plants, preferably thin-leaved ones, should be present. The fish may not spawn on the first day, but hopefully they will in a few days. As with many fish, the most common time for this fish to spawn is early in the morning. Actual spawning can be stimulated by morning light. I suggest that the breeding tank is located to allow this light to fall on the aquarium. About 200-300 eggs are laid per female. The eggs are between 2 and 2.5 mm in diameter and are orange in color. Parents have been reported not to eat their own eggs. There have not been enough reports of this to make sure it is normal. Certainly, if they don’t eat their own eggs, this is unusual behavior for an egg-spreading tetra. The eggs hatch in 4-6 days. Babies are about 7mm long. This is larger than the fry of most small fish that spread eggs.
Raising the babies
Despite the large size of African Long-finned Tetra babies, they have small mouths and need infusoria (protozoa) for the first few days. After this, they can eat newborn brine shrimp and other tiny live foods. Live foods of suitable sizes can be supplemented with liquid and dry fried foods. Fingerlings need frequent feeding and plenty of room to grow. Great care must be taken with the quality of the water, avoiding the accumulation of ammonia, nitrite or nitrate. For the early stages, an air-operated foam filter may be the safest type to use.