Nephasoma abyssorum abyssorum (Koren and Danielssen, 1876)

Saiz-Salinas, J. I., 2007, Sipunculans and echiurans from the deep Angola Basin, Journal of Natural History 41 (45 - 48), pp. 2789-2800 : 2792-2793

Nephasoma abyssorum abyssorum (Koren and Danielssen, 1876)

Material. Sta. EBS no. 318, two; Sta. EBS no. 328, one; Sta. AT no. 333, four; Sta. no. 334, 17; Sta. AT no. 337, 28+fragments; Sta. EBS no. 338, three; Sta. AT no. 339, eight+fragments; Sta. EBS no. 340, 32+3?; Sta. AT no. 343, one+fragments; Sta. EBS no. 344, 35; Sta. EBS no. 348, seven+one?; Sta. EBS no. 350, three; Sta. AT no. 351, one.

Description. Trunk 1.5–10 mm long and 0.4–1 mm wide. Introvert 2–4 mm in length and 0.2–0.5 mm in width. Skin smooth, thicker at the posterior end of the trunk. Its surface is marked by small skin bodies, elliptical in shape, 7–12 Mm in diameter at the trunk end. Hooks 20–40 Mm tall are scattered. Its shape in side-view is rather characteristic with a cylindrical thickness on its convex edge and a lateral flattening on its concave side. Two retractors attached in the trunk.

Remarks. The smooth and cylindrical trunk without papillae and the shape of the hooks help in the identification of the species. In several sampling sites (nos 318, 333, 334, 337– 340, 343, 344, 348, 350, 351) it occurs with the common N. diaphanes from which it is easily differentiated by the lack of papillae under the microscope. Some specimens have been found in tubes made of shell remains (nos 339, 340, 344) and also in burrows inside small pumice stones (no. 334). This is a common species at bathyal and abyssal depths of the north-east Atlantic and it has been previously recorded from the area by Cutler and Cutler (1987) at 2992–5124 m depth.