Pseudoikedella achaeta ( Zenkevitch, 1958 )

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

Pseudoikedella achaeta ( Zenkevitch, 1958) ( Fig. 2A, B )

MATERIAL EXAMINED. — Porcupine Abyssal Plain, BENGAL 3, Discovery 229, stn 13200#94, 48º50.99’N, 16º26.03’W, 4847 m, 25.VII.1997, 2.

DESCRIPTION

Colour of proboscis and trunk is light pink in preserved state. Trunk of larger specimen is 50 mm long and 10 mm across broadest part. Corresponding measurements of smaller specimen are 28 mm and 13 mm. Proboscis is truncate, 4 mm in length, rounded at distal end; lateral margins curl inwards and unite proximally to form funnel around mouth ( Fig. 2A ). Junction of proboscis and trunk is stout. Anterior end of trunk covered with small round- ed papillae, rest of integument is smooth. Single genital pore located few millimetres away from anterior end of trunk ( Fig. 2A ). Ventral setae absent.

Single gonoduct located on right side of nerve cord ( Fig. 2B ). Gonostome lateral near terminal extremity, located on a small stalk. Dorsal vessel prominent, passes anteriorly and enters proboscis. Neurointestinal vessel missing probably damaged. Intestine filled with soft mud. Anal vesicles are two slender tubes with sparsely distributed ciliated funnels.

REMARKS

Pseudoikedella achaeta was originally described by Zenkevitch (1958) from specimens collected at great depths from the southern part of the Sea of Okhotsk. This species has also been reported from several other localities in the North Pacific and Tasman Sea ( Zenkevitch 1958, 1966; Zenkevitch & Murina 1976). Recently, P. achaeta was recorded and described from Antarctica waters by Saiz-Salinas et al. (2000).

Figures

FIG. 2. — A, B, Pseudoikedella achaeta (Zenkevitch, 1958); A, ventral view of anterior part of female; B, gonoduct; C-F, Achaetobonellia ricei n. sp.; C, ventral view of anterior part of female; D, gonoduct; E, internal morphology; F, anal vesicles. Abbreviations: av, anal vesicle; dv, dorsal vessel; gd, gonoduct; gp, gonopore; gs, gonostome; int, intestine; nc, nerve cord; niv, neurointestinal vessel; oes, oesophagus; ph, pharyx; pr, proboscis; re, rectum; vv, ventral vessel. Scale bars: A, C, E, 3 mm;