Bucktooth Tetra

Geographic Origin and Biotope: Amazon River basin (Brazil) and Branco River. Prefers open waters with little vegetation and sandy bottoms in rivers in full current, hunting frantically.

Taxonomy and Morphology: Bucktooth Tetra (Exodon paradoxus). Large lethal characin. Its jaws (oversized compared to the tapered tetra body) are armed with massive and protruding teeth (buckteeth) similar to incisors, to tear off scales.

Social Behavior: The poor man's Piranha. Hunts in "wolf packs", frantic and unstoppable. Intra-specific aggression is so high that in small groups (e.g. 5-8 individuals) the dominants will tear each other to pieces until the last one dies. Keep only in schools of AT LEAST 15-20.

Coloration and Sexual Dimorphism: Iridescent metallic shiny silver background. It has two marked black spots, one circular before the tail and one rhomboidal halfway down the flank. All fins blaze with a bright yellow or blood red. Slender males.

Aquarium Setup: Immense aquarium (at least 150 cm / 60 inches) for almost or totally single-species use. Vast, immense areas for free swimming. Use very massive sand and roots. Plants will be fine, but will often be "nibbled" by mistake in the heat of meals.

Diet and Feeding: Carnivorous lepidophage. In nature it survives even by tearing scales from other fish. In the aquarium it accepts everything: flakes, pellets, thawed fish, krill. Upon introduction of food the water boils (violent feeding frenzy).

Water Quality: Needs very sustained current and very high oxygenation. Being a hyper-competitive and voracious eater, the filters must be excellent to dispose of the high organic load.

Compatibility and Tankmates: NOT a community fish. Strictly forbidden any tankmate, under penalty of the poor cohabitant being stripped alive with bites. It is possible to attempt cohabitation in mastodontic tanks only with extremely armored (and adult) Loricariids.

Aquarium Reproduction: They scatter eggs among the foliage, and then immediately feed on their own work. It is necessary to isolate the breeders on grids on the bottom.

Risks and Diseases: Decimation of the school. Failure to respect the minimum numbers (at least 15-20 fish) and tanks that are too short (<120 cm / 48 inches) invariably lead to the extermination of the entire group due to deadly quarrels in a few months.