Chinese Algae Eater (CAE)

Geographic Origin and Biotope: Asia (Thailand, Mekong basin, Chao Phraya river). River streams with moderate to strong current, full of smooth sun-kissed rocks and bare trunks.

Taxonomy and Morphology: Chinese Algae Eater - CAE (Gyrinocheilus aymonieri). Asian sucker fish, actually NOT Chinese but Thai. Huge and highly effective sucker mouth under the snout, which it uses to resist rapids.

Social Behavior: Dr. Jekyll and Mr. Hyde. When very young (5-6 cm / 2 inches) they are tireless peaceful workers. Becoming adults (over 15 cm / 6 inches) they turn into "psychopathic killers", extremely territorial and aggressive even with their own kind.

Coloration and Sexual Dimorphism: The wild form has an olive-gray back with a black zigzag line along the flank (mesh-like). In stores, 95% is sold in the "Gold" variant, completely lemon yellow or faded orange. Females are mastodontic.

Aquarium Setup: Due to their adult size they need sturdy tanks (150 cm / 60 inches). Large smooth river rocks to cling to for rest, powerful filters with strong jets and caves to define their territorial boundaries.

Diet and Feeding: Juveniles: avid algivores, they clean the glass in hours. Adults: they switch to a 100% carnivorous/protein diet, refusing algae and stealing food (granules, tubifex) from any other fish by headbutting them.

Water Quality: Not delicate on parameters (tolerates soft and hard waters), but needs high oxygenation. Poor maintenance pushes its territorial nature to historic highs of violence.

Compatibility and Tankmates: The worst community tankmate. Reaching maturity, it uses its sucker mouth to attach itself to the flanks of slow fish (Angelfish, Discus, Orandas), literally sucking their mucus and skin (causing ulcerations and death). Can only cohabit with large and fast Barbs (e.g. Tiger Barbs).

Aquarium Reproduction: Never reproduced in home aquariums. In Asian farms (where the Golden forms are obtained) huge tanks with mass hormonal injections are used to force spawning.

Risks and Diseases: The purchasing mistake par excellence. Thousands of aquarists buy it as a cute little 4 cm (1.5 inch) "glass cleaner" for a 30 liter (8 gallon) tank, only to find themselves with a 25 cm (10 inch) yellow monster that kills Corydoras and flays goldfish.