Re-description of Daphnia (Ctenodaphnia) from lakes in the Khumbu Region, Nepalese Himalayas, with the erection of a new species, Daphnia himalaya, and a note on an intersex individual

Abstract

We present here a detailed description of Ctenodaphnia-type Daphnia specimens collected from lakes in the Nepalese Himalayas between 1994 and 2004, including mature females and adult males. The specimens examined share certain diagnostic traits with Daphnia tibetana (Sars 1903), and others with Daphnia fusca (Gurney 1906). A re-appraisal of their previous synonymy with D. fusca and a comparison with all published descriptions of similar species from the region indicate that they represent a new species named here as Daphnia himalaya. The chance discovery of a sex intergrade of the same species allowed a description of the secondary sexual characteristics in this interesting and rare intermediate state to be reported, and its possible ecological implications to be discussed, as well.