2009年2月22日 星期日

中美尼加拉瓜湖Astyanax屬一新種

文獻來源: Bussing, W.A. 2008. Astyanax cocibolca, a new characid (Pisces: Ostariophysi) from Lake Nicaragua, Central America. International Journal of Tropical Biology 56(3): 1361-1370. [全文網址]

Abstract: Astyanax cocibolca, a small filter-feeding species is a new characid species endemic to Lake Nicaragua. It is distinguished from the syntopic Astyanax aeneus by its high gill raker count, slender body, upturned snout, long maxillary bones, conical outer premaxillary teeth, lower number of scales above lateral line, more intense black lateral band, smaller size, and trophic niche partitioning. At present the new species utilizes the open-water habitat at least as a nursery where young can feed on the rich plankton population. Adults feed on copepoda, cladocera, fruits, seeds and algae. The bulk of the adult population presumably resides inshore.