Threatened fishes of the world: Oxygymnocypris stewartii (Lloyd 1908) (Cyprinidae)

Abstract

Common name: Naked schizothoracin (English). Local name: Jian Luo Li (Chinese). Figure from Wu and Wu (1991). Conservation status: Endangered—China Red Data Book of Endangered Animal, Pisces (Yue and Chen 1998). Identification: Body elongate and slightly compressed, snout long and pointed, mouth large and terminal, upper jaw slightly longer than lower jaw (Wu and Wu 1991; Chen and Cao 2000), upper lip relatively developed, lower lip narrow and divided into two lobes, barbels absent, body naked but with a small number of irregular scales on part of pectoral girdle and anal, anal scales developed, usually two rows and each row 23–28. Dorsal fin posteriorly located and its last simple ray strong, pectoral fin short. Body color grayish-black on back with small dark spots (Yue and Chen 1998). Dorsal iv+7, Anal iii+5, Pectoral i+16–20, Pelvic i+8–9 (Wu and Wu 1991). Distribution: Endemic to the middle Yarlung Tsangpo River in Tibet, China. Abundance: Scarce. Captivation is a rare occurrence (Yue and Chen 1998). Habitat and ecology: Coldadapted freshwater fish, found in deep water with slow-moving flow. Feeds on aquatic insects, other small fishes, and invertebrates. (Wu and Wu 1991; Yue and Chen 1998). Reproduction: Reproduction takes place from May until July (Wu and Wu 1991). No reports of captive breeding. Threats: Restricted distribution, slow growth process and prolonged sexual maturity period hinder the survival of this species (Yue and Chen 1998; Qi 2008). Since 1950s the fishing activities, may have already driven, and will continue drive O. stewartii into decline (Yue and Chen 1998). Conservation recommendations: Fishing in spawning season and illegal fishing activities should be strictly prohibited. Habitat protection should be continued. Researches on genetic diversity of wild populations and artificial breeding are necessary to sustain the species. Environ Biol Fish (2009) 86:351–352 DOI 10.1007/s10641-009-9526-z