Threadfin Acara

Geographic Origin and Biotope: South America (Amazon River basin, Essequibo and Trombetas). Prefers calm and muddy/sandy banks covered with sunken foliage and branches ("blackwater" and slow rivers), where the water is warm and oxygen is stable.

Taxonomy and Morphology: Thread-finned Acara (Acarichthys heckelii). A very particular Cichlid, a taxonomic bridge between Geophagus and Acara. Laterally compressed body. The dorsal and caudal fins possess extraordinarily long filamentous extensions ("Thread-finned").

Social Behavior: Peculiar peaceful but gregarious nature when young, becomes territorial in adulthood (especially during reproduction). It is an atypical "Earth-eater": it chews the bottom expelling the sand from its gills to sift for food.

Coloration and Sexual Dimorphism: Incredibly reflective: blue-gray / golden base, sprinkled with iridescent red, blue and green scales. A showy vertical black stripe or spot crosses the flank and the eye. Males slightly larger with more extensive red and blue filaments on the fins.

Aquarium Setup: Minimum 120 cm (48 inches) for a small group. STRICTLY a 5-8 cm (2-3 inches) thick layer of very fine sand (not sharp quartz or gravel) to allow oro-branchial filtration ("sifting"). Large roots and foliage complete the layout. Will uproot delicate plants.

Diet and Feeding: Omnivorous detritivore. In nature it sifts micro-crustaceans from the bottom. Feed with balanced sinking pellets for Cichlids, frozen bloodworms, brine shrimp, daphnia and occasional pieces of zucchini and spirulina.

Water Quality: Requires very warm tropical waters (25-30°C / 77-86°F), soft and with a slightly acidic or neutral pH (6.0-7.2). The continuous stirring of the sand requires an excellent pre-filter or fine-mesh sponges to safeguard the external filter impeller.

Compatibility and Tankmates: Relatively calm for a medium South American cichlid. Excellent with large Tetras (Neons, Bleeding Heart), Severums, peaceful Corydoras. Avoid large or brutal Cichlids (Oscars, Red Terror) that would tear its fragile fins.

Aquarium Reproduction: Complex but fascinating. In nature they dig tunnels or holes under the sand up to half a meter long! In the tank, by providing semi-buried terracotta pots (tunnels), the pair will lay eggs hanging from the ceiling ("cave-spawner"), tenaciously protecting them.

Risks and Diseases: The extensive filamentous fins are magnets for the biting of other fish (fin nipping). Sharp sand will irremediably devastate the mouthparts and gills, leading to fatal necrosis.