ON CLASSIFICATION OF COLOSSOMA BRACHYPOMUM AND ITS CULTIVATION CHARACTERISTICS

Colossoma brachypomum native to Amazon region was introducedinto China mainland in 1985. After a comparative study it was identified to beColossoma brachypomum (Cuvier, 1818). The fish has following morphologicalcharacteristics: Body laterally compressed shaped; Depth 1.9±0.33; in standardlength; Head 3.8±0.47; Length of caudal pedunele 13.4±1.33; Its depth 8.0±0.63;Snout 4.2±0.89 in head; Eye 6.0±0.35; Interorbital space 1.8±0.2; Depth ofcaudal peduncle 0.6±0.09 in its length; D iii-13-15,P i-15-l7,A iii-22-23, V i-7-8;Lateral-line scales 87-94; Gill rakers 32-38. It was found in cultural practice thatthe fish is omnivorous, and can tolerate high salinity (10 PPT) and low levelof dissolved oxygen (0.48mg/L). The suitable growth temperature is 22-30℃, butit will die below 8℃. It is considered to be a potential cultivated freshwater speciesdue to its easy culture, fast growth and convenient capture with a sein. Thechromosome number of the fish is 2n=54, n=27.