Galaziella baikalensis, a new genus and species of chirocephalid (Crustacea: Branchiopoda: Anostraca) from Russia and the zoogeography of East Asian Anostraca

Galaziella baikalensis gen. et sp. nov. is described from Olkhon Island, Lake Baikal, Russia. The genus is assigned to the family Chirocephalidae Daday, 1910, on the basis of the following features: the male has two-segmented antenna, its basal segment bearing two leaf-shaped antennal appendages, all thoracopods with two distinctly divided pre-epipodites, and genital segments containing two clearly defined seminal vesicles. Galaziella is well distinguished from other genera of the family by the apical part of the penes, armed with two spiniform processes at each apex, instead of a single spine or toothed plate. Such male genital processes have not yet been found in Chirocephalidae, so that the diagnosis of the family is revised and two sub-families are proposed herein. Up to the present, 10 species belonging to 7 genera, including Galaziella baikalensis, and 5 families of Anostraca – Artemiidae, Branchinectidae, Branchipodidae, Chirocephalidae, and Thamnocephalidae – have been found in East Asia and its adjacent areas, including the Russian Far East, Mongolia, China, Korea, and Japan. The list includes all synonymic taxa. A distribution map and a key to the East Asian species of the family Chirocephalidae are provided. Received: November 22, 1999 / Accepted: May 2, 2000