Additions to the aspidochirotid, molpadid and apodid holothuroids (Echinodermata: Holothuroidea) from the east coast of southern Africa, with descriptions of new species
Author
THANDAR, AHMED S.
text
Zootaxa
2007
2007-03-01
1414
1
1
62
http://dx.doi.org/10.11646/zootaxa.1414.1.1
journal article
10.11646/zootaxa.1414.1.1
11755334
5077005
DC93A9BC-D24E-44AD-99AF-79CACCCFB984
Holothuria (Mertensiothuria) hilla
Lesson, 1830
Figure 10
Holothuria hilla
Lesson, 1830: 226
, pl. 79.
Holothuria (Thymiosycia) hilla
Massin, 1999: 55
(synonymy & records before 1999).
Holothuria (Mertensiothuria) hilla
Samyn & Massin, 2003: 2500
, fig. 5 A–E, 11C, 12F (records after 1999).
Type
MNHNP
, EcHh 542
.
Type
locality
Borabora Island
(
Society Island
)
.
Previous southern African record
Mozambique
and east coast of
South Africa
.
Material examined
SAM-A27931
,
Sodwana Reef
,
Rotenone
,
St. RW
76–15, scuba-gear,
25.vii.
1976
, 17 m
,
1 spec.
,
SAM-
A27932,
Isipingo Beach
,
KwaZulu-Natal
,
26 iv 1979
, rock pool,
K.S. Ganga
&
G.C. Naidu
,
1 spec.
(juvenile).
Description
Sodwana specimen (
SAM-A
27931) 45x
16 mm
, strongly contracted, eviscerated and somewhat mutilated due to previous dissection. Colour, in alcohol, greyish with pale areas around podia. Mouth sub-ventral, collar absent; anus terminal, no special anal papillae. Podia scattered, better developed ventrally with some indication here of their arrangement in rows, few and reduced dorsally. Tentacle ampullae short (<0.5 mm). Polian vesicle single, elongate; stone canal straight, madreporite spherical. Cuvierian tubules present. Body wall table discs
46–65 µm
(mean
54 µm
) (
Figure 10A
), smooth, squarish to roundish, with a single series (or only four) marginal holes; spire
33–42 µm
high (mean
36 µm
), with single cross-bar, terminating in ring of few short spines. Buttons (
Figure 10B
) smooth,
50–75 µm
(mean
61 µm
), regular, with 3–5 pairs of large holes. Ventral podial deposits reduced tables, buttons
57–109 µm
(mean
74 µm
), large multilocular perforated plates (
Figure 10C
),
98–154 µm
x
32–109 µm
, and end-plates; buttons often asymmetrical and/or reduced to a single series of holes. Table disc of dorsal podia
54–67 µm
(mean
58 µm
), spire
37–44 µm
(mean
41 µm
); buttons
61–100 µm
(mean
83 µm
) and button-like plates and rods (
Figure 10D
)
33–135 µm
(mean
91 µm
), the latter usually perforate at ends. Tentacle rods slender,
28–144 µm
(mean
63 µm
), spinulated at ends (
Figure 10E
). Longitudinal muscles with deposits resembling letters of alphabet in both script and print form.
Table discs of Isipingo specimen (
SAM-A
27932)
42–70 µm
, with 8–10 marginal and sometimes a second series of much smaller holes outside these; buttons
50–105 µm
.
FIGURE 10.
Holothuria (Mertensiothuria) hilla
Lesson, 1833
. SAM–A27931. A. tables from ventral body wall; B. buttons from ventral body wall; C. plates from ventral podia; D. rods from dorsal podia; E. rods from tentacles. (All drawn to same scale)
Distribution
Tropical-subtropical Indo-West Pacific Ocean,
0–
30 m
.
Habitat
Benthic, shallow, inshore.
Remarks
Despite the absence of a distinct ring around the anus, the Sodwana specimen is still referred to the widely distributed
H. (M)
hilla
. It is, however, briefly described above as there are some significant differences. The Isipingo specimens, definitely referable to
H. hilla
,
have smaller spicules than those given for the species by
Rowe (1969)
, but their dimensions match those of
Pearson’s (1910)
Mozambique
specimen and of Samyn & Massin’s (2003)
Kenya
material. The latter workers recently removed the species from
Thymiosycia
and transferred it to
Mertensiothuria
.