Two new ancorabolid species (Copepoda: Harpacticoida: Ancorabolidae) from South Korea

Abstract

Members of the predominantly deep-water family Ancorabolidae are among the most morphologically distinct and ornate copepods in the Harpacticoida. During an extensive faunistic survey of Korean marine benthic copepods, two new species of Ancorabolidae were recorded, belonging to the genera Arthuricornua Conroy-Dalton, 2001 and Dendropsyllus Conroy-Dalton, 2003, respectively. Both sexes of each species were represented in the muddy sediment collected at 100 m depth off the south coast of Korea. Arthuricornua n. sp. differs from the type and only species, A. anendopodia Conroy-Dalton, 2001, by the presence of three pairs of elongate dorsal processes on the second to fourth pedigerous somites, the absence of the inner seta on the third endopodal segment of legs 2&#8211 4 in the female, and the presence of a hyaline membranous extension near the ventral posterior margin of the caudal ramus. Dendropsyllus n. sp. is differentiated from its three congeners on the basis of the lateral armature on the antennary endopod (two spines and one seta) and the 1-segmented condition of the endopods of legs 3&#8211 4. This contribution presents the first report of the subfamily Ancorabolinae in East Asia. Concise differential diagnoses accompanied by illustrations of both sexes are given as well as remarks on relationships with previously described species. A key to species of Dendropsyllus is presented.corabolidae were recorded, belonging to the genera Arthuricornua Conroy-Dalton, 2001 and Dendropsyllus Conroy-Dalton, 2003, respectively. Both sexes of each species were represented in the muddy sediment collected at 100 m depth off the south coast of Korea. Arthuricornua n. sp. differs from the type and only species, A. anendopodia Conroy-Dalton, 2001, by the presence of three pairs of elongate dorsal processes on the second to fourth pedigerous somites, the absence of the inner seta on the third endopodal segment of legs 2&#8211 4 in the female, and the presence of a hyaline membranous extension near the ventral posterior margin of the caudal ramus. Dendropsyllus n. sp. is differentiated from its three congeners on the basis of the lateral armature on the antennary endopod (two spines and one seta) and the 1-segmented condition of the endopods of legs 3&#8211 4. This contribution presents the first report of the subfamily Ancorabolinae in East Asia. Concise differential diagnoses accompanied by illustrations of both sexes are given as well as remarks on relationships with previously described species. A key to species of Dendropsyllus is presented.