Loreto Tetra

Geographic Origin and Biotope: Originating from the Loreto region in the Peruvian Amazon (hence the name). Populates slow-flowing black or very clear water streams, protected by the dense shade of the rain forest and with substrates rich in dry leaves.

Taxonomy and Morphology: Loreto Tetra (Hyphessobrycon loretoensis). Slender and slightly compressed. It has an elegant shape very similar to that of Neon tetras, suitable for slipping quickly into intricate vegetation.

Social Behavior: Extremely peaceful, shy, and strongly gregarious. Needs large schools (10+ individuals) to feel safe and show stationary daytime swimming. Without enough companions, it will hide perpetually.

Coloration and Sexual Dimorphism: Very delicate but spectacular livery: olive-gray back with a thick lower black band, topped by a bright silvery/golden line. The caudal fin is a dense cherry red. Females are stockier, males slender.

Aquarium Setup: An Amazonian "Blackwater" setup is recommended: dim light (floating plants like Limnobium), intricate wood to create shadows, fine sand, and alder cones or Catappa leaves to release reassuring tannins.

Diet and Feeding: Micro-predator. Readily accepts crushed flakes or small granules. Regular supplementation with small live/frozen food (nauplii, daphnia, cyclops) is indispensable to make the red tail shine.

Water Quality: Prefers acidic (pH 5.5-6.5) and very soft waters, and temperatures slightly below the Amazonian average (22-26°C / 72-79°F). It is sensitive to organic swings and nitrate accumulations. Requires a well-matured tank.

Compatibility and Tankmates: Ideal companion in a Peruvian biotope with Apistogramma (e.g. A. cacatuoides), Corydoras panda, Otocinclus, and other small tetras (Neons). Absolutely unsuitable to coexist with large cichlids, predators, or frenetic fish (e.g. Danios).

Aquarium Reproduction: Quite complex. Requires very acidic water (pH < 6.0) filtered with peat, with low lighting. The pair spawns on fine-leaved plants; it is essential to remove the parents promptly.

Risks and Diseases: Very susceptible to bacterial fin infections and dropsy if kept in hard, calcareous water, or if exposed to a polluted environment due to poor filtration or lacking maintenance.