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 (Theelothuria) pseudonotabilis
sp. nov.
Figure 18
Diagnosis
Perhaps a small species,
holotype
59 mm
long. Colour, in alcohol, an admixture of browns, dorsum with eight pairs of dark blotches, whitish areas around bases of scattered tubefeet. Cuvierian tubules present. Body wall tables few, of
three types
: commonest type with circular to subcircular, slightly spinose to smooth disc (
40–75 µm
), low spire (
20–50 µm
) terminating in ring of about six blunt teeth, rarely rim knobbed or tables modified to fenestrated spheres; second type commoner than third and of
Mesothuria
type with smooth disc (ca.
60 µm
) with 6–7 large marginal holes and spire terminating in compact, often tripartite cluster of teeth; third type rare, disc oblong, up to
100 µm
, with 2–3 series of holes, smaller marginally. Buttons numerous, slightly knobbed,
30–60 µm
, holes often occluded.
Etymology
The new species is so named as it was initially thought to represent
H. notabilis
Ludwig.
Type
SAM-A27943
;
Inhaca Island
,
Mozambique
,
vi. 1971
,
B. Kensley
.
Type
locality
Inhaca Island
,
Mozambique
.
Material examined
Holotype
only.
Description
Specimen small, badly contracted, 59 x
30 mm
; cylindrical, tapering slightly at both ends. Colour, in alcohol, an admixture of browns, paler ventrally; dorsum with eight pairs of dark blotches, whitish areas around bases of podia. Mouth terminal, tentacles 18, short, with light brown disc,
2 mm
in diameter. Collar not evident. Anal papillae unequal, in five groups. Podia as scattered tubefeet, shorter dorsally, papilliform posteriorly. Calcareous ring (
Figure 18N
) high, radial plates longer than wide, with deep anterior ampullary notch and posterior slightly prolonged beyond level of interradial plates to form rudimentary bifurcations; interradial plates half the length of radial plates but just as broad with anterior, median tooth-like projection and deeply concave posterior margin. Polian vesicle single, short, midventral. Stone canal short, free, situated slightly to left of mesentery; madreporite well calcified, pyriform (
Figure 18M
). Right respiratory tree longer but left more profusely branched, both uniting before opening into cloaca. Gonad as single tuft of branched tubules on left of mesentery. Cuvierian tubules 15, short, thick, curved, attached to base of left respiratory tree.
FIGURE 18.
Holothuria (Theelothuria) pseudonotabilis
sp. nov.
Holotype. SAM–A27943. A. Table from dorsal body wall (from side); B. tables from dorsal body wall; C. table from ventral body wall (from side); D. reduced ventral tables; E. fenestrated sphere from ventral body wall; table from ventral body wall (
Mesothuria
type); G. same (from side); H. table with multilocular disc; I. buttons from dorsal body wall; J. buttons from ventral body wall; K. rods from.dorsal podia; L. rod from ventral podium; M. madreporite; N. part of calcareous ring. (A & G scale a; H & I scale b)
Spicules of body wall tables and buttons. Tables few, of
three types
: commonest
type
(
Figure 18A–C
) with circular to subcircular, slightly spinose to smooth disc (
40–75µm
, mean
50 µm
) with about eight marginal holes and a low spire (
20–50 µm
), terminating in a ring of about six blunt teeth, disc and spire frequently reduced (
Figure 18D
) but rarely rim knobbed or tables modified into fenestrated spheres (
Figure 18E
); second
type
like that of
Mesothuria
(
Figure 18 F,G
) with a smooth, slightly lobed disc (ca.
60 µm
), perforated by 3– 4 central holes and 6–7 large marginal holes; spire low, terminating in a compact, often tripartite, cluster of teeth; third
type
of tables (
Figure 18H
) rare, found only ventrally, disc large, oblong, up to
100 µm
, with uneven margins and perforated by four small central holes, a series of slightly larger holes outside these and usually another incomplete series on outside. Buttons (
Figure 18 I, J
) numerous, slightly knobbed,
30–60 µm
, oval with usually a distinct shaft and smooth, slightly undulating, knobbed margins, holes 3(-7) pairs, often occluded, especially ventrally, where only a pair of holes may be present; rarely buttons smooth or modified into fenestrated ellipsoids. Podia with end-plates and elongate rods (up to
150 µm
) with central and/or terminal perforations (
Figure 18L, K
). Tentacles, longitudinal and cloacal muscles without deposits.
Distribution
Known only from
type
locality.
Remarks
This specimen was initially identified and described by the writer (see
Thandar 1984
) as
H. (T.) notabilis
Ludwig
but due to inaccurate cutting and pasting it appears in the thesis as
H. (T.) maculosa
Pearson
(see Remarks under
H. maculosa
above). Dr Rowe (pers. comm.), who examined the original description and slides, thought that the specimen perhaps represents a new species, close to
H. (T.) maculosa
, and this was recently verified by both Massin & Samyn (pers. comm.), who examined my
holotype
. Since then, I have had the opportunity to examine
H. (T.) notabilis
in the Natural History Museum (London) and conclude that the current specimen differs from it in possessing a different type of calcareous ring,
three types
of body wall tables, less spinose table discs and in the occasional presence of fenestrated spheres. In
H. (T.) notabilis
the radial plates of the calcareous ring are prolonged far beyond the posterior margin of the interradial plates and the anterior projections of the radial plates are rounded. Further, the tables of Ludwig’s species are mostly reduced, the discs very spinose, and fenestrated spheres absent. The new species can also be referred to the subgenus
Cystipus
but, due to its similarities with both
H. maculosa
and
H. notabilis
, it is here classified in
Theelothuria
. In any case both
Theelothuria
and
Cystipus
are closely related (see
Rowe 1969:125
).