Amazon red-tail tetra

Geographic Origin and Biotope: Rio Paraguay basin (Brazil, Paraguay). Inhabits moderate-flow streams, clear rivers and flooded zones with dense riparian vegetation, where it moves agilely in schools.

Taxonomy and Morphology: False Bloodfin Tetra (Aphyocharax dentatus). Often confused with A. anisitsi. Differs by a slightly larger size, a mouth equipped with tiny visible "teeth" (hence "dentatus") and a more silvery livery.

Social Behavior: Very active schooling fish. It is essential to keep it in groups of at least 8-10 specimens. If in small numbers, it becomes shy or exhibits "fin-nipping" behaviors towards other slow tankmates.

Coloration and Sexual Dimorphism: Elongated silvery body. The anal and caudal fins feature extensive deep blood-red spots. Adult females are noticeably stockier and swollen with eggs; males are slimmer and have tiny hooks on the anal fin.

Aquarium Setup: 80 cm (32 inches) tank or larger, with ample free swimming space in the center and dense bushes of plants on the sides. A dark bottom and not too blinding lighting (or shielded by floating plants) are preferable.

Diet and Feeding: Omnivorous micro-predator. Readily consumes quality flakes, but to keep the bright red color of the fins lit it needs brine shrimp, bloodworms and daphnia (both live and frozen) administered regularly.

Water Quality: Very robust and tolerant towards chemical value fluctuations. However, it does not like an excessive accumulation of nitrates. Efficient filtration with a moderate water flow is ideal.

Compatibility and Tankmates: Excellent for robust community aquariums. Coexists perfectly with Corydoras, Ancistrus and dwarf or peaceful Cichlids (e.g. Bolivian Ram). Avoid insertion with long-finned fish (e.g. male Guppies or Bettas).

Aquarium Reproduction: They scatter eggs among fine-leaved plants. Breeders must be conditioned with live food and separated in a breeding tank set up with mops or moss, then removed immediately after spawning to prevent cannibalism.

Risks and Diseases: Resistant to most common diseases. The main risk comes from jumping out of the aquarium (uncovered tanks) or from lethal intra-specific aggression if kept in groups of only 2 or 3 individuals.