On some lesser known sea cucumbers in the Natural History Museum, UK (Echinodermata: Holothuroidea)
Author
Thandar, Ahmed S.
text
Zootaxa
2019
2019-10-23
4688
3
361
381
journal article
25163
10.11646/zootaxa.4688.3.3
a9af11dc-d705-48ed-96fb-3b323accc19e
1175-5326
3516791
B8F6F528-F616-4EA1-8CA7-FA2FA89A34B9
Thyone
?
elegans
Norman, 1869
(? synonym of
T. roscovita
Hérouard, 1889
Figure 5
Material examined.
NHMUK 1985.10
.4.14,
Siteb, E.
of
Seagull Bank
,
Rhum
,
285 m
,
Dr B. Earll
,
Marine Conservation Society
,
1 spec.
FIGURE 5.
Thyone
?
elegans
Norman, 1869
/?
T. roscovita
Hérouard, 1889
.
Description.
Specimen U-shaped; off-white in alcohol, anterior and posterior ends greyish, length
46 mm
; breadth in mid-body
5 mm
. Mouth and anus terminal, the latter with five anal teeth. Tube feet minute, retracted, scattered, more numerous ventrally with some indication of their arrangement in double rows anteriorly and posteriorly, with scattering in mid-body. Calcareous ring and associated structures absent. End plates present in tube feet but no ossicles were evident in body wall and tube feet.
Remarks.
It is suspected that because of the complete lack of body-wall ossicles and the presence of darker coloured anterior and posterior ends and tube feet end plates, the specimen might represent
Thyone elegans
(?synonym
T. roscovita
) but as the calcareous ring and associated structures are absent, a definite conclusion is not possible. The species could also be
T. inermis
Heller
but
McKenzie (1991)
states that
T. inermis
always has deposits in the anal region and is perhaps a clinal variation of
T. roscovita
(?=
T. elegans
).