The Pretty Tetra is known under several different common names in English, including Black wedge tetra and Garnet tetra. Its scientific name is Hemigrammus pulcher. The Pretty Tetra hails from the upper Amazon River basin where it has been found near Iquitos, Brazil, and in some of the tributaries of the Peruvian Amazon. The Pretty Tetra is not included in the IUCN Red List of Threatened Species.
The Pretty Tetra can be recognized on the black wedge that is found on the back part of the fish’s body right under the deep red area. The base colour of this tetra is greenish and there is a hint of a shoulder spot. The body is decorated with golden to greenish highlights. The largest scientifically measured Pretty Tetra was 3.3 cm long (slightly longer than 1 1/4 inch). They are however known to grow bigger in captivity.
Wild Pretty Tetras live where the water temperature is 23 – 27°C (73 – 81°F), the pH 5.0-6.0 (acidic) and the dH range 5-12 (soft). Keeping optimal water conditions is especially important if your want to spawn Pretty Tetra fish in your aquarium. The Pretty Tetra feeds on small crustaceans, worms and plants in the wild. Always keep this fish in groups consisting of at least 5-6 individuals.
In the wild, the Pretty Tetra spawns among plants and the eggs will normally hatch within 20-24 hours. A well planted aquarium is therefore a good idea, since this will resemble the natural breeding grounds for the Pretty Tetra.
Sexing Pretty Tetras is a bit tricky when they are not in breeding condition. The males are however equipped with a characin hook on the anal fin. Females in good condition will have heavier bodies than the males. As mentioned above, you should always keep at least six Pretty Tetras together.
A five gallon aquarium (roughly 20 L) is large enough to serve as breeding aquarium for a reasonably sized group of Pretty Tetras. A plastic mesh basket can be used to keep the adult fish from eating the eggs. Suspend the basket one inch from the bottom.
The Pretty Tetra appreciates acidic water, so peat moss is a good idea. The water should also be very soft.
During the mating process, the male will press the female against a suitable surface. You can for instance include artificial spawning strips when you set up the breeding aquarium. The first spawning will normally contain a smaller amount of eggs than the following spawnings.
When the spawning is over, the adults should ideally be moved before the eggs hatch and the fry swims up through the mesh and gets eaten. Newly hatch Pretty Tetra fry look like slivers of glass and will stay on the bottom for 2-3 days before they become free swimming. They will appreciate having a piece of Java moss or similar to hide in. The tiny fry can eat infusoria during the first week, and then gradually move up to microworms and newly hatched brine shrimp.