New species and a new record of sea cucumbers from deep waters of the South African temperate region (Echinodermata: Holothuroidea)
Author
Thandar, Ahmed S.
text
Zootaxa
2009
2013
30
42
journal article
10.5281/zenodo.185850
51cc254b-682d-4934-8072-2d4434028c6f
1175-5326
185850
Molpadia musculus
Risso, 1826
Figure 3
Molpadia musculus
Risso, 1826
: 293
;
H.L. Clark, 1907
: 165
, Pl. 11;
Pawson, 1977
: 100
, text-figs: 1, 2, 3, 4a–c, e, Map 1 (synonymy).
Material examined.
SAM-A28044, ‘Nansen 404’, Trawl TO16, west coast of
South Africa
(
33° 53.7’S
,
17° 26.9’E
),
407 m
,
10.iv.2007
, Louise Lange, 1 spec.
Description.
Specimen large, well preserved, barrel-shaped with short tail. Length along ventral surface
80 mm
, width of mid-body
15 mm
, tail length
2 mm
. Colour uniformly violet except at extreme anterior end and the tail which are white to greyish-white. Body wall rough to the touch. Phosphatic deposits abundant (
Figure 3
B). Calcareous deposits of body wall delicate, localised mostly in tail and at extreme anterior end, and include fusiform and tri-forked rods, up to 600 µm, with 1 – 4 (usually 3) small central holes and easily fragmented racquet-shaped bodies (
Figure 3
A); anchors may be present but only a single broken one detected in the body wall sampled, may be of foreign origin.
FIGURE 3.
Molpadia musculus
Risso.
SE micrograph of deposits from tail region. A. racquet-shaped ossicles; B. rods and phosphatic bodies.
Distribution.
Essentially cosmopolitan but not yet known from above the Arctic Circle,
35–5205 m
. (
Pawson 1977
)
Remarks.
Pawson (1977)
revised the molpadiid sea cucumbers of the Southern, Atlantic, Pacific and Indian Oceans, describing four new species and presenting a key to the nine species he recognized as valid. Since then, a few more species have been added. After having examined
170 specimens
, Pawson showed that
Molpadia musculus
is a very varied species with its calcareous deposits changing drastically with age. His synonymy of
M. musculus
hence appears rather drastic but despite this he comments that it is incomplete “for the limits of variation of the species are far from clearly defined.” (
Pawson 1977:100
). Based on this, the single southern African specimen, briefly described above, appears referable to this species. It is characterized by the presence of fusiform rods in the body wall, best developed in the tail and much smaller racquet-shaped bodies. Pawson states that anchors, rosettes of racquet-shaped plates and tables with three or more perforations and a solid spire are usually absent in specimens over
30 mm
, “having being transformed into very numerous light to dark red phosphatic deposits.”(
Pawson 1977:100
). Hence the propensity of phophatic bodies and the scarcity of racquet-shaped bodies and spired tables. This is the second record of this species from southern Africa, the first is that of
Cherbonnier (1965)
from a single
41 mm
specimen collected at
480 m
from
Cabinda
(
Angola
). The South African material differs from Cherbonnier’s specimen by the rarity of racquet-shaped deposits and spired tables, perhaps due to its size and/or age.