? Sluiterina sp.

(Fig. 4A, B)

MATERIAL EXAMINED. — East Equatorial Atlantic Ocean. Gulf of Guinea, BIOZAIRE 3, CP 21, stn R 9, 05°47.4990’S, 009°43.8038’E, 3130 m, 3.I.2004, 1 ♀.

DESCRIPTION

Colour of trunk is reddish-brown. Only small, basal stump of proboscis is attached to trunk, rest is missing. Posterior end of trunk is missing, only 40 mm of anterior end is intact.Trunk is cylindrical, 9 mm across broadest part. Integument is thick and opaque. Papillae microscopic, round, aligned in transverse rows. Genital pore is transverse slit located 4 mm away from anterior tip of trunk (Fig. 4A). Ventral setae absent.

Internally, only foregut and small portion of midgut is intact, rest of alimentary canal is missing including blood vascular system. Contents of gut moulded into oval faecal pellets. Single gonoduct, located on left side of nerve cord, consists of two parts (Fig. 4B). Tube leading from distal, spherical accessory sac opens into middle of saclike, thick-walled gonoduct (Fig. 4B). Proximal end of gonoduct passes under nerve cord to open in median line. Stalked, funnel-shaped gonostome also opens in middle of gonoduct close to opening of accessory sac (Fig. 4B). Gonostomal lips with small lobes around margin. Elongate ovary located on right side of nerve cord adjacent to gonoduct (Fig. 4B). Anal vesicles not seen.

REMARKS

The present specimen from the East Equatorial Atlantic Ocean has been tentatively assigned to the genus Sluiterina on account of the presence of a single gonoduct and the absence of ventral setae. Unfortunately the specimen is incomplete. Except for the gonoduct which is intact and well preserved, the rest of the internal organs are missing. The structure of the gonoduct, with an accessory sac opening into it, is rather unusual. To date, such a gonoduct has not been observed in any other bonelliid species. The taxonomic status of this specimen is uncertain and will have to await a detailed examination of additional material from that region.It is very likely that additional specimens may reveal that he specimen on hand belongs to a new genus.