Flying Fox

Geographic Origin and Biotope: Southeast Asia (Thailand, Indonesia). Frequents fast rivers or forest streams with solid substrates (rocks and wood) where abundant algal biofilm (aufwuchs) proliferates.

Taxonomy and Morphology: Flying Fox (Epalzeorhynchos kalopterus). Benthic cyprinid, often mistaken in shops for Crossocheilus siamensis (SAE - Siamese Algae Eater). It has a downward-facing mouth equipped with flaps for scraping.

Social Behavior: In youth a solitary worker, tolerates other fish on the bottom. As it becomes an adult it becomes distinctly intolerant, hyper-territorial and often openly aggressive towards fish with a similar silhouette.

Coloration and Sexual Dimorphism: Torpedo-shaped body. Olive-brown background above, marked horizontal black line surrounded by a thin blazing golden line above it. The pectoral, dorsal and anal fins are very dark (black/red and edged with white), a key distinction from the SAE (which has them transparent).

Aquarium Setup: A mature and spacious aquarium is essential (min. 120 cm / 48 inches). Many seasoned woods and rounded stones. It rests picturesquely on large leaves such as Anubias and ferns. The water must be oxygenated.

Diet and Feeding: Biofilm scraper, will devour young algae. Not satisfied with just algae: requires a substantial protein integration (bloodworms, brine shrimp, sunk pellets). Often in adulthood it prefers feeds to algae.

Water Quality: Requires clean waters but tolerates a certain amount of humic acids. Being a current fish, oxygen crashes immediately send it into anoxia.

Compatibility and Tankmates: Must be introduced in SINGLE specimens. Cohabits well with mid-sized water column fish such as Rasboras, Gouramis, or Barbs, but will relentlessly attack other Epalzeorhynchos (including the famous "Labeo" bicolor or frenatus).

Aquarium Reproduction: Never achieved in home aquariums (often relies on hormonal injections in Southeast Asian farms).

Risks and Diseases: Risk of wrong purchases (mistaken for the perfect "algae eater"). It will never eradicate black beard algae (BBA) like the real Siamese Algae Eater does.