Sub-Recent Ostracoda from Qilian Mountains (NW China) and their ecological significance

Abstract

23 ostracod species have been recorded from surface and short core samples from the Qilian Mountains, NW China. Brooks and rivers, small shallow meadow and oxbow pools and a lake were sampled at an altitude ranging from 2900 m to 3570 m asl. Brooks were dominated by Candona rawsoni, Ilyocypris cf. bradyi and/or Ilyocypris lacustris and Limnocythere inopinata. In river habitats Candona candida and Eucypris sp. were most abundant. Meadow pools with peaty, dystrophic waters mainly contained valves of Ilyocypris cf. bradyi and/or Ilyocypris lacustris and Eucypris sp. whereas the latter was replaced by Heterocypris incongruens in a shallow oxbow pool. Candona rawsoni, Cyclocypris ovum and Ilyocypris echinata were the most frequent species in the freshwater Lake Luanhaizi. The recorded taxa are mainly distributed in the holarctic realm but Fabaeformiscandona danielopoli and Ilyocypris echinata appear to be restricted to the cold mountainous region in China.