New findings and two new species of the genus Colossendeis Jarzynsky, 1870 (Pycnogonida, Colossendeidae), with a morphometric analysis for species from the Southern Ocean

Abstract

In this paper, specimens belonging to the pycnogonid genus Colossendeis Jarzynsky, 1870 collected during the Antarctic Polarstern XXIII/8 cruise (November 23, 2006, to January 30, 2007) were studied. In this collection, the following thirteen species have been identified, two of them being proposed as new species: Colossendeis frigida Hodgson, 1907, C. megalonyx Hoek, 1881, C. wilsoni Calman, 1915, C. engirmatica Turpaeva, 1974, C. arundorostris Fry & Hedgpeth, 1969, C. scotti Calman, 1915, C. lilliei Calman, 1915, C. drakei Calman, 1915, C. glacialis Hodgson, 1907, C. australis Hodgson, 1907, C. tortipalpis Gordon, 1932, C. pseudofrigida sp. nov., and C. bamberi sp. nov. All species are diagnosed and their taxonomic status discussed. C. frigida, C. engirmatica, and C. arundorostris extend their known depth range. C. arundorostris has been found for the first time outside the Ross Sea. The finding of C. engirmatica represents the first record after its original description. The new species are described, illustrated, and compared with their closest congeners. Finally, we carried out a cluster analysis (Bray-Curtis similarity index) based on a data-matrix of 49 Antarctic and Sub-Antarctic Colossendeis species and 26 morphological characters.