Description and phylogenetic affinities of two new species of Nomadolepis (Eucestoda, Hymenolepididae) from Eastern Palearctic.

Two new species of hymenolepidid cestodes belonging to the genus Nomadolepis are described from small mammals in western Siberia and the Far East, Russian Federation. Nomadolepis fareasta n. sp. is described from the striped dwarf hamster Cricetulus barabensis in Amurskaya Oblast' and Nomadolepis shiloi n. sp. is described from the Eurasian harvest mouse Micromys minutus from Novosibirskaya Oblast' and Amurskaya Oblast'. Nomadolepis fareasta n. sp. differs from Nomadolepis merionis, Nomadolepis ellobii and N. shiloi n. sp. in having a substantially longer strobila, longer cirrus-sac and wider ovary. Furthermore, N. fareasta n. sp. can be readily distinguished from its congeners by the arrangement of the testes and the number and size of rostellar hooks. Nomadolepis shiloi n. sp. differs from N. merionis, N. ellobii and N. fareasta n. sp. by the number and length of the rostellar hooks, the presence of irregular transverse anastomoses as well as the length of the cirrus-sac and position of the cirrus-sac in relation to the poral ventral osmoregulatory canal. Morphological differentiation of the two new species from morphologically similar Palearctic species of the related genus Rodentolepis (sensu lato) from rodents is also provided. Phylogenetic affinities of Nomadolepis were studied for the first time using partial sequences of the nuclear ribosomal 28S DNA gene. Phylogenetic analysis strongly supported the status of Nomadolepis as a separate genus closest to Pararodentolepis.

Neoskrjabinolepis nuda n. sp. from shrews on Sakhalin Island, Russia, with a taxonomic review of Neoskrjabinolepis Spasskii, 1947 (Cestoda: Cyclophyllidea: Hymenolepididae).

Neoskrjabinolepis (Neoskrjabinolepidoides) nuda n. sp. is described from the shrews Sorex unguiculatus (type-host), S. gracillimus, S. isodon and S. caecutiens on Sakhalin Island, Russia. The new species is characterised by: rostellar hooks 40-44 microm long and provided with small epiphyseal thickening of the handle; a long (95-100 microm) cirrus consisting of basal region with claw-shaped spines, a parabasal region with thin needle-shaped spines and an unarmed distal region; a cirrus-sac extending well into the median field; and 15-22 eggs per gravid uterus. A review of the species of Neoskrjabinolepis Spasskii, 1947 is presented. Currently, this genus includes nine species and is divided in two subgenera on the basis of strobilar development, which is gradual in the subgenus Neoskrjabinolepis (four species) and serial in the subgenus Neoskrjabinolepidoides Kornienko, Gulyaev & Mel'nikova, 2006 (five species). An amended generic diagnosis and an identification key to Neoskrjabinolepis spp. are presented.