Sipunculus (Sipunculus) E. Cutler and Cutler, 1985

Acd, 2000, Sipuncula from Hainan Island (China), Journal of Natural History 34, pp. 2187-2207 : 2190

Subgenus Sipunculus (Sipunculus) E. Cutler and Cutler, 1985 Sipunculus (Sipunculus) nudus Linnaeus, 1766

Material. Meixia, 9 April 1992, one specimen; Qinglan, 5 November 1990, one specimen; Qinglan, 7 November 1990, one specimen; Qinglan, 2 April 1992, 12 specimens; Qinglan, 5 April 1992, two specimens; Qukou, 13 March 1992, four specimens; Qukou, 14 March 1992, six specimens; Sanya (Luhuitou), 24 November 1990, one specimen; Sanya, 27 March 1992, 16 specimens.

Description. Trunk 16±115 mm in length and 3±17 mm in width. Introvert is shorter (about 60%) than the trunk length. Longitudinal musculature is split into 27±34 bands, with a predominance of 30 bands for most specimens. The nephridia are 30±50% attached to the body wall by mesenteries. Digitate processes on a bilobulate brain are apparent.

Discussion. The studied specimens show a wide size range, which is considered normal for this species. Many of them are, however, quite small compared with the most frequently recorded lengths for this species (Cutler, 1994). All the characters accord well with previously published descriptions, although the length of the attachment surface of the nephridia to the body wall is close to the highest values recorded in the literature (around 50%).

With a cosmopolitan distribution, the species has been recorded in the area investigated (as well as in Hainan Island) several times (Leroy, 1936, 1942; Chen and Yeh, 1958; Chen, 1963; Murina, 1964, 1989; Li, 1985b; Manning and Morton, 1987; Li et al., 1990, 1992b). It is usually found in the intertidal zone, rarely surpassing 30 m of depth. The species shows a preference for sandy bottoms, as exempli®ed by the specimens of this collection. These were obtained in a local market since this is one of the species that the inhabitants of Hainan use in their diet (Chin, 1947) .