Zenkevitchiola brevirostris Murina 1978

Zenkevitchiola brevirostris Murina, 1978

(Fig. 3 A-C)

MATERIAL EXAMINED. — Porcupine Abyssal Plain, BEN- GAL 2, Discovery 226, stn 13078#11, 48°53.19’N, 16°35.98’W, 4844 m, 1.IV.1997, 2 ♀♀.

DESCRIPTION

Colour of proboscis is white,trunk is pink in preserved state.Proboscis is truncate,lateral margins curl inwards forming a shallow groove. Proboscis of larger female is 14 mm in length; trunk is 24 mm long and 8 mm across broadest part. In smaller female with trunk length of 10 mm, proboscis is only 4 mm long. Proximal end of proboscis forms a cup with slit on ventral side (Fig. 3A).Trunk is sac-like with bulbous posterior end (Fig. 3A). Papillae microscopic, more clearly discernible in contracted region of trunk, aligned roughly in transverse rows. Integument is very thin and transparent.Coils of gut visible through body wall (Fig. 3A). Ventral setae absent.

Internally, single minute, gonoduct (Fig. 3B) is located on right side of nerve cord.

Gonostome on long stalk, basal in position. Alimentary canal not highly coiled; gut contents consist of fine sand not moulded into faecal pellets. Neurointestinal vessel is single throughout. Anal vesicles two, small blind-ending tubes opening on either side of cloacal chamber (Fig. 3C).

REMARKS

The species Z. brevirostris is described originally from a single female collected at a depth of 755 m from southern Tasmania by Murina (1978). The present specimens are considered to be Z. brevirostris on account of the thin and transparent body wall, nonbifid proboscis, single gonoduct with a basally located gonostome, tubular anal vesicles and the absence of ventral setae.Minor differences are apparent in the size of the specimens and in the distribution of the dermal papillae. According to the description provided by Murina(1978), low rounded papillae are present on the anterior third and posterior quarter of the trunk.

This is a first report on the occurrence of this species in the Atlantic.