Yunnan schizothoracin

Yunnan schizothoracin

　　Class: Osteichthyes, Subclass: Ostariophysi, Order: Cypriniformes, Suborder: Cyprinoidei, Family: Cyprinidae, Subfamily: Schizothoracinae, Genus: Schizothorax, Subgenus: Racoma, Species: Yunnan schizothoracin

　　Common name

　　　　Mianyu (面鱼)

　　External morphological characteristics

　　　　The Yunnan schizothoracin has an elongated, slightly laterally compressed body. It generally grows to about 15 cm in length, with larger individuals reaching up to 30 cm. The head is conical, and the mouth is subterminal. The lower lip is fleshy, with a free posterior edge divided into two lateral lobes and no distinct middle lobe. The postlabial groove is discontinuous. The inner side of the lower jaw is slightly cornified but does not form a sharp edge. There are two pairs of barbels, nearly equal in length, slightly longer than or equal to the eye diameter. The rostral barbels reach just below the rear edge of the nostrils, while the maxillary barbels extend to the middle area beneath the eyeball. The pharyngeal teeth are arranged in three rows, slender, and with curved tips. Scales are small; the abdominal area from the branchiostegal membrane to just below the pectoral fin is scaleless. The lateral line scales are larger than the body scales, and there are large scales on both sides of the anal and caudal fins. Dorsal fin III 8, with the unbranched hard spines having serrated posterior edges. Anal fin II 5. The body is grayish-blue on the back and sides, covered with numerous irregular small black spots, and the belly is silvery white.

　　Habitat and behavior

　　　　In natural conditions, this species prefers clear rivers, reservoirs, and lakes. Under artificial farming conditions, it can be raised in ponds. It is a medium to small-sized sub-cold water fish and is endemic to Yunnan. Its current population is very small.

　　Reproduction

　　　　Male maturity age: 2–4 years; Female maturity age: 3–6 years; Maturity body length: 216 mm (females), 150 mm (males); Maturity weight: 200 g (females), 60 g (males); Absolute fecundity: 1,656–33,855 (avg. 10,980); Relative fecundity: 15.53–48.24 (avg. 24.43); Spawning water temperature: 14–17°C; Spawning type: demersal and adhesive; Gonadal maturation cycle: 12 months; Egg characteristics: demersal and adhesive; Spawning habit: eggs laid on gravel.