Apionsoma murinae ( Cutler, 1969 )

Saiz-Salinas, J. I., 2007, Sipunculans and echiurans from the deep Angola Basin, Journal of Natural History 41 (45 - 48), pp. 2789-2800 : 2794

Apionsoma murinae ( Cutler, 1969)

Material. Sta. AT no. 339, 10+one?; Sta. AT no. 343, one+one fragment; Sta. AT no. 347, two; Sta. EBS no. 348, one+ one juvenile; Sta. AT no. 349, six .

Description. Trunk 1.5–15 mm long and about 1 mm wide. Introvert 4–20 mm in length (up to three times longer than trunk) and about 0.3 mm in width. Skin smooth and thick mostly, translucent in some parts. Scattered ovoid papillae up to 0.1 mm in diameter over the middle part of the trunk. Large mammiform papillae up to 0.2 mm in diameter are located at the posterior end of the trunk. Hooks not observed since the apical part is missing. Four retractors originate in the central or posterior third of the trunk. Bilobed nephridia (no. 339) in some specimens dissected, others unilobed (nos 347, 349). Nephridiopores are a little in front of anus.

Remarks. The presence of an introvert longer than the trunk and large papillae over the trunk are diagnostic for A. murinae . Cutler (1969) recognized two subspecies based on the presence/absence of a secondary lobe on the nephridia. Since conspicuous lobes have not been observed in all the dissected material and the external characters to distinguish subspecies are problematical, it seems more advisable to identify the specimens to specific level. The species is widespread in cold waters (up to 5260 m depth) across the northern Atlantic and down to 15 ° S. It has been previously recorded north to the investigated area by Cutler and Cutler (1987).