Report on deep-sea bonelliids (Echiura) from the East Equatorial Atlantic Ocean
Author
Biseswar, Ramlall
School of Biological and Conservation Sciences, University of KwaZulu-Natal (Westville Campus), Private Bag X 54001, Durban 4000 (Republic of South Africa) biseswar @ ukzn. ac. za
biseswar@ukzn.ac.za
text
Zoosystema
2010
2010-03-31
32
1
139
154
http://www.bioone.org/doi/abs/10.5252/z2010n1a7
journal article
10.5252/z2010n1a7
4f2631ca-c253-4e8b-a201-bb4deef0c5e0
1638-9387
4520699
Alomasoma belyaevi
Zenkevitch, 1964
(
Fig. 1A, B
)
MATERIAL EXAMINED. —
East Equatorial Atlantic Ocean.
Gulf of
Guinea
, BIOZAIRE 3, CP 10, stn ZB-D,
5°50.6300’S
,
8°20.0600’E
,
3977 m
,
19.XII.2003
,
1 ♀
. — CP 11, stn ZB-D,
05°50.5840’S
,
008°20.0380’E
,
3978 m
,
20.XII.2003
,
1 ♀
. — CP 22, stn
R
10,
05°46.9700’S
,
009°44.1828’E
,
3121 m
,
3.I.2004
,
1 ♀
.
DESCRIPTION
Colour of trunk of preserved specimens is reddishbrown. In one female only small proximal part of proboscis is attached to trunk, rest damaged.Trunk is cylindrical,
30 mm
long and
12 mm
across broadest part. Part of body wall damaged on ventral side of trunk. In other two specimens, probosces are missing and posterior ends of trunk are damaged. Anterior end of trunk covered with small rounded papillae, remainder of trunk smooth and devoid of papillae. Single genital pore is located about
5 mm
away from anterior end of trunk (
Fig. 1A
). Ventral setae absent.
Gonoducts one pair (
Fig. 1B
), large, sac-like, uniting proximally beneath nerve cord and opening to exterior by single genital pore. In one female, gonoducts compactly filled with eggs. Gonostomes small, basal in position (
Fig. 1B
). Gonostomal lips with minute lobes around margin. Except for oesophagus and foregut, rest of alimentary canal is damaged in all specimens including blood system and anal vesicles.
REMARKS
Alomasoma belyaevi
was originally described by
Zenkevitch (1964)
from the North-West Pacific Ocean at depths ranging from
2826-2843 m
.
Zenkevitch (1966)
also reported the occurrence of this species in the Gulf of
Panama
.
Alomasoma belyaevi
has been recorded and briefly described by Saiz-Salinas
et al
. (2000) from Antarctic and adjacent waters. The latter authors have described male specimens in the genus
Alomasoma
for the first time. According to
Stephen & Edmonds (1972)
all the specimens have been found at great depths.
The anatomy of this species is fairly well known as it has been described from numerous specimens.
Alomasoma belyaevi
is close to
A. rhynchollulus
DattaGupta, 1981
from the North Atlantic.According to
DattaGupta (1981)
,
A. rhynchollulus
differs from all the other species in the genus in possessing a minute triangular proboscis. The discovery of
A. belyaevi
from the East Equatorial Atlantic Ocean is a new record for this region which considerably extends its range of distribution.