Sinev A.Yu. 2004. Redescription of two species of the genus Leydigiopsis Sars, 1901 (Branchiopoda, Anomopoda, Chydoridae // Invertebrate Zoology. Vol.1. No.1: 75–92 [in English].
Department of Invertebrate Zoology, Biological Faculty, Moscow State University, Vorobievy Gory, Moscow 119899, Russia. E-mail: email@example.com
ABSTRACT: The two insufficiently known South American cladoceran species, Leydigiopsis curvirostris Sars, 1901 and Leydigiopsis megalops Sars, 1901, were redescribed from the type material. Detailed morphology of the trunk limbs of these species and morphology of male L. megalops were studied for the first time. Species of the genus Leydigiopsis combine clearly plesiomorphic characters — primitive morphology of head pores, male postabdomen similar to that in females, and apomorphic characters — long rostrum, antennules of unusual morphology, broad postabdomen with well developed postanal denticles. Analysis of morphology suggests that Leydigiopsis belongs to the group of the small tropical genera, like Euryalona, Tretocephala, long ago separated from the main trend of Aloninae and retain numerous plesiomorphic characters.
KEY WORDS: Cladocera, Leydigiopsis, morphology, systematics.