Revision of the genus Heteropsyllus (Copepoda: Harpacticoida) with description of a new species from the Laptev Sea and establishment of new genus

Abstract

A phylogenetic analysis of species of the genus Heteropsyllus T. Scott, 1894 was carried out on the basis of morphological characteristics. The polyphyly of the genus was shown; two species, Heteropsyllus nunni Coull, 1975 and H. pseudonunni Coull et Palmer, 1980, were transferred to the genus Coullopsyllus gen.n. in the family Nannopodidae. From other genera, Coullopsyllus gen.n. differed in the 3-segment-ed endopod of the first leg and 2-segmented endopod of the fourth leg. It differed from Heteropsyllus in the absence of sexual dimorphism in the third leg and in the four setae on the fifth leg of the male. A new species, H. spiridonovi sp.n. from the Laptev Sea, which belongs to the H. curticaudatus species group, was also described. It differed from closely related species by the following combination of characteristics: smooth surface of somites, 2-segmented exopod of antenna, free exopod of mandible, three endites on syncoxa of maxilla, and the absence of a cuticular area on the fifth pair of legs.