2009年4月17日 星期五

生存倍受威脅的魚類: Oligosarcus schindleri (脂鯉科)

文獻來源: Carvajal-Vallejos FM, Muñoz H, De La Barra E, Argote A. 2009. Threatened fishes of the world: Oligosarcus schindleri Menezes & Géry 1983 (Characidae). Environmental Biology of Fishes doi: 10.1007/s10641-009-9458-7

Common name: Platincho (Bolivia). Conservation status: Threatened (Sarmiento and Barrera 2003). Identification: Oligosarcus schindleri (Ostariophysii: Characiformes: Characidae) is silvery with a longitudinal dark band and a vertically elongated humeral spot. Jaws and ectopterygoids have caniniform and conical teeth. A iv17–19. Adults can reach 100 mm standard length (SL). Distribution: Water bodies around Cochabamba city, Bolivia (Río Grande watershed) (17°32′ S/66°05′ W). A single record exists to the upper Río Chapare (Menezes and Géry 1983). Habitat and ecology: Undisturbed creeks and muddy ponds between 2,200 and 3,400 m above sea level. Lives in some localities with the exotic species Cyprinus carpio Linnaeus 1758, Gambusia affinis (Baird and Girard 1853) and Odontesthes bonariensis (Valenciennes 1835). Its main diet are Cladocerans (Delgadillo and Muñoz 2007; Vallejos et al. 2007). Reproduction: Spawns the year around. The peak of female reproduction period is from October to March (Muñoz et al. 2008). Female and male maturity sizes are 40 and 36 mm SL, respectively (Patiño and Muñoz 2007). Threats: Critical water pollution and discharge level of creeks (Maldonado et al. 1998), predation and food competition with O. bonariensis (Vallejos et al. 2008), selective removal by local fishermen to avoid a supposed predation on the more economically valuable O. bonariensis, and its restricted distribution. Conservation recommendations: To restore water bodies around Cochabamba city and avoid introduction of more exotic species that can compete with this fish.