Pethia tiantian Pethia tiantian Pethia tiantian is a species of cyprinid fish that has only been recorded from streams in the vicinity of Putao in the far north of Myanmar. It grows to a length of SL. It is generally brownish with a dark vertical bar just behind the operculum and a round dark blotch on the caudal peduncle. Other "Pethia" species are similarly marked but "P. tiantian" can be distinguished by its longer lateral line, reaching all the way back to the base of the caudal fin. "P. didi", a similarly marked species found in the same drainage basin, differs from
Copella (genus) observation. The pectoral fins are positioned immediately behind the operculum or gill cover, while the pelvic fins are further back along the body, about midway between the head and the caudal peduncle. The dorsal fin is positioned above and slightly behind the pelvic fins, and midway between the pelvic fins and the tail fin is the anal fin. The tail fin is forked in shape. Males usually possess more elongated and ornate unpaired fins than females. In the case of "C. arnoldi", the tail fin of the male is somewhat asymmetrical, the upper lobe being larger than the lower lobe,