Zenkevitchiola, Murina, 1978

Biseswar, Ramlall, 2010, Report on deep-sea bonelliids (Echiura) from the East Equatorial Atlantic Ocean, Zoosystema 32 (1), pp. 139-154 : 152

Zenkevitchiola sp.

( Fig. 5F )

MATERIAL EXAMINED. — East Equatorial Atlantic Ocean. BIOZAIRE 1, KGS 27, stn ZB-D, 05°49.937’S, 008°21.57’E, 4000 m, 10.I.2001, 1 ♀.

DESCRIPTION

Colour of proboscis is cream, trunk is beige in preservative. Proboscis is truncate 0.5 mm long with lateral margins curled ventrally forming a groove leading to mouth; distal extremity is curved and widened ( Fig. 5F ). Trunk is pear-shaped ( Fig. 5F ) 0.7 mm in length and 0.4 mm across broadest part. Integument is thin and transparent. Papillae minute, round, visible at anterior end of trunk, rest of integument is smooth. Ventral setae absent. Internal organs not seen, probably damaged due to poor preservation.

REMARKS

The specimen on hand has been tentatively assigned to the genus Zenkevitchiola Murina, 1978 on account of the absence of ventral setae, the thin and transparent integument and the structure of the proboscis. As the specimen is minute it is very likely that it is still a juvenile. The proboscis of the present specimen resembles that of Z. brevirostris Murina, 1978 , described from a single female collected near southern Tasmania ( Murina 1978). According to Murina (1978) and Edmonds (1987), the distal extremity of the proboscis is curved and widened. The monotypic genus Zenkevitchiola is characterised by the presence of a single gonoduct located on the right side of the nerve cord, a basally located gonostome and tubular anal vesicles that taper distally.

A closer study of additional material in the future will help resolve its taxonomic position. The species Z. brevirostris has been recorded and redescribed from the North-East Atlantic by Biseswar (2006). Its discovery in the East Equatorial Atlantic Ocean is a new record for the region and extends its range of distribution considerably.

Figures

FIG. 5. — A, B, Protobonellia mitsukurii Ikeda, 1908; A, ventral view of female; B, ventral seta; C, Protobonellia sp., ventral view of female; D, E, Pseudobonellia sp.; D, ventral seta; E, gonoducts; F, Zenkevitchiola sp., ventral view of female; G, H, Bruunellia sp.; G, posterior end of trunk of female showing anal rosette;H, posterior end of trunk cavity showing rectum and anal vesicle.Abbreviations: ar, anal rosette;av, anal vesicle;gd, gonoduct;mt, male tube; nc, nerve cord; niv, neurointestinal vessel; oav, opening of anal vesicle; pr, proboscis; re, rectum; se, seta; vv, ventral vessel. Scale bars: A, H, 2 mm; B, E, 1 mm; C, D, F, 0.25 mm; G, 5 mm.