Sipunculans and echiurans from the deep Angola Basin
Author
Saiz-Salinas, J. I.
text
Journal of Natural History
2007
2007-12-31
41
45 - 48
2789
2800
http://dx.doi.org/10.1080/00222930701782187
journal article
10.1080/00222930701782187
1464-5262
5233566
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.