Sluiterina sibogae ( Sluiter, 1902 )

Biseswar, Ramlall, 2005, Report on some deep-sea echiurans (Echiura) of the North-East Atlantic, Zoosystema 27 (1), pp. 37-46 : 39-41

Sluiterina sibogae ( Sluiter, 1902) ( Fig. 1 E-G)

MATERIAL EXAMINED. — Porcupine Abyssal Plain, BENGAL 1, Discovery 222, stn 12930#73, 48º50’N,

Biseswar R.

DESCRIPTION

Colour of proboscis and trunk of preserved specimen is cream. Proboscis 21 mm long, truncate, rounded anteriorly; lateral margins curl inwards forming a tubular structure ( Fig. 1E ). At proximal end lateral margins of proboscis unite to form lower lip ventral to mouth. Trunk 25 mm long and 7 mm across broadest part. Integument thin and transparent. Intestine with pellet-like faeces visible through transparent body wall. Papillae microscopic at anterior and posterior ends of trunk; integument smooth and devoid of papillae in middle region. Ventral setae absent.

Internally, only basal fragment of gonoduct present on left side of nerve cord. Pharynx is a thick tube, not clearly demarcated from oesophagus ( Fig. 1F ).

Intestine long and highly coiled, densely packed with oval faecal pellets ( Fig. 1F ).

Dorsal and neurointestinal vessels arise from wall of foregut. Neurointestinal vessel is single throughout. Anal vesicles arborescent, consisting of several branches opening into rectum ( Fig. 1G ).

REMARKS

The species Sluiterina sibogae is known from a single female from Indonesia collected at a depth of 4391 m. Although the present specimen is much smaller in size, it approaches the description given by Sluiter (1902) especially in the structure of the proboscis. According to Sluiter (1902) the proboscis is Thalassema -like with the lateral edges close together giving it a tubular appearance. Similarities are also evident in the distribution of the dermal papillae. Unfortunately, the anal vesicles have not been described by the latter author. In the specimen from the North-East Atlantic there is a single gonoduct with a basally located gonostome. All the other species in the genus Sluiterina differ from the specimen on hand in possessing anal vesicles that are bushy, consisting of numerous, thin, unbranched excretory tubules resembling a string mop.

Figures

FIG. 1. — A-C, Torbenwolffia galatheae Zenkevitch, 1966; A, ventral view of anterior part of female; B, gonoduct; C, anal vesicle of one side; D, Alomasoma nordpacificum Zenkevitch, 1958, gonoducts; E-G, Sluiterina sibogae (Sluiter, 1902); E, ventral view of anterior part of female; F, anterior part of alimentary canal; G, anal vesicles. Abbreviations: av, anal vesicle; dv, dorsal vessel; gd, gonoduct;