A New Species of Snailfishes (Liparidae) of the Genus Careproctus from the Northern Slope of the Aleutin Basin (Bering Sea)

Abstract— A new species of snailfishes Careproctus schmidti sp. nov. from the northwestern part of the Bering Sea is described. The specimen was caught in the mesobenthal of the Aleutian Basin at a depth of 852–862 m (holotype ZIN no. 56 620—female TL 194 mm). It is distinguished from the majority of congeners of the North Pacific Ocean by a set of features: a large number of vertebrae (63) and rays in the fins (D 56, A 50, P 34, C 10), the presence of two pairs of pleural ribs, a relatively elongated (21% SL) pectoral fin with a notch and short lower lobe (12% SL), two suprabranchial pores, simple teeth, naked skin, and black peritoneum. In terms of meristic features, the new species is similar to three North Pacific species, but it differs from C. colletti in a short lower lobe of the pectoral fin, a flattened disc of triangular outlines, and a longer gill slit. It differs from C. roseofuscus by a lower body, a pectoral fin ventrally located and anus which opens immediately behind the disc. It differs from C. ambustus in purple-lilac color, fewer in number simple teeth with sharp apexes, in vertical and higher disposition of gill slit, shorter lower lobe of the pectoral fin, disc shape and position of the anus. The presence of an ovipositor may indicate existence of complicated reproductive behavior (such as carcinophilia or other types of reproductive commensalism). The northwestern slope of the Aleutian Basin, where a specimen of C. schmidti was caught, is located in the zone of influence of the Bering Slope Current and seasonal upwelling associated with the rise of deep waters. The composition of the ichthyocene in the area of ​​capture is given, including up to 20 species, dominated by Macrouridae.