Aspidosiphon (Paraspidosiphon) fischeri

Vargas, Rita & Kawauchi, Gisele Y., 2010, Sipunculans and Echiurans of Isla del Coco (Cocos Island), Costa Rica, Zootaxa 2557, pp. 60-68 : 65

Aspidosiphon (Paraspidosiphon) fischeri ten Broeke, 1925

Material examined. Bahia Chatham, 15 m, 22 May 2008, five specimens, 3.5– 8 mm; Punta Ulloa 8 m, 28 May 2008, one specimen, 12 mm; Isla Manuelita, 4.5 m, coral, 23 May 2008, three specimens, 2–4 mm; 4.5 m, 29 May 2008, one specimen, 2 mm.

Additional material. Bahia Chatham, 30 m, 12 October 2007, five specimens, 5mm; Silverado 11m, 23 May 2008, 1 specimen, 2–4 mm.

Description: This species has separate longitudinal muscle bands which are most apparent anteriorly. The shield is made up of many closely spaced irregular small units each with a granular surface; shield units are less densely spaced near the shield edges. Hooks are bidentate and are followed by unidentate pale pyramidal hooks proximally on the introvert. Retractor muscles extend approximately 95% of the body length and attach near the small caudal shield. The nephridia extend 20–40% of the body length.

Habitat. Subtidal calcareous rock, 4.5– 30 m.

Distribution. Aspidosiphon (Paraspidosiphon) fischeri is known to range from Pacific Costa Rica to Ecuador and the Galapagos Islands ( Cutler 1994, Vargas & Dean 2009).