Franke's Tetra

Geographic Origin and Biotope: Originating from the mountain and foothill basins of the Peruvian Amazon (often in the Ucayali River system). Inhabits cool, crystal-clear, and fast-flowing streams with gravelly bottoms and round pebbles.

Taxonomy and Morphology: Hyphessobrycon frankei. Characterized by a very robust and stocky profile. Morphologically belongs to the Peruvian "high altitude tetras", sharing the characteristics of the genus, including a strong mouth and adipose fin.

Social Behavior: Formidable and tireless swimmer, strongly schooling. Must be kept in large schools (10-15 specimens) so that its exuberance does not turn into nervousness. Interacts perpetually within the school.

Coloration and Sexual Dimorphism: Simple but attractive: opalescent silvery-gray or greenish base, with two distinct vertical dark bars ("humeral spots") behind the brachial operculum. Reddish fins in males, which are also visibly slenderer.

Aquarium Setup: Long tank (minimum 80-100 cm / 32-40 inches) with a moderate or strong current (use of powerheads). The ideal bottom consists of rounded stones, coarse gravel, and tenacious rheophilic plants like Microsorum and Anubias.

Diet and Feeding: Voracious omnivore. Not being demanding, it accepts flakes and sinking pellets from the first days. However, its liveliness is best supported by regularly providing insects (daphnia) and frozen worms.

Water Quality: A true "cool water tetra". Prefers very moderate temperatures (22-26°C / 72-79°F), never excessively hot. Neutral or weakly acidic water (pH 6.0-7.0) and a very high rate of dissolved oxygen.

Compatibility and Tankmates: Ideal companion for "hillstream" or brook biotopes. Coexists wonderfully with Chaetostoma (Bulldog Pleco), large cool-water Corydoras (e.g. C. paleatus), and rheophilic Loricariids. Harmless to smaller fish.

Aquarium Reproduction: Rarely documented in captivity, but similar to that of congeners. They lay pelagic eggs at dawn, triggered by temperature drops akin to rainfall. No parental care.

Risks and Diseases: The greatest danger is asphyxia or thermal stress if placed in "Discus" aquariums with temperatures constantly over 28°C (82°F). Under such conditions, it rapidly deteriorates.