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) duoturriforma
sp. nov.
Figure 17
Diagnosis
Perhaps a small species,
type
40 mm
. Colour, in alcohol, white with scattered dark blotches. Podia minute, papilliform, scattered. Papillose collar evident. Anus encircled by five clusters of papillae. Tentacles?20, whitish. Cuvierian tubules absent. Spicules of body wall tables and buttons. Tables of two sizes: either with a large disc (
42–81 µm
) of the
Mesothuria
type
and a tall spire (
42–68 µm
) with 2–3 cross-bars or a small disc (
39–65 µm
) and a short spire (
26–39 µm
) with usually a single cross-bar, smaller
type
usually at bases of podia. Buttons restricted to bases of podia and anal region, elongated or oval (
45–77 µm
, mean
65 µm
), with 3–4 pairs of holes and few knobs.
Etymology
The specific name refers to the
two types
of tables found in the body wall.
Type
SAM-A27942
.
Type
locality
Off Lala Nek
,
KZN
,
South Africa
,
72 m
.
Material examined
Holotype
only,
NMDP
,
St. ZD
6, off
Lala Nek
(
27° 13.0 ' S
,
32° 49.7 ' E
),
72 m
,
7 vi 1990
.
Description
FIGURE 17.
Holothuria (Theelothuria) duoturriforma
sp. nov.
Holotype. SAM–A27942. A. buttons from base of podium; B. knobbed podial buttons; C. large body wall tables from side; D. large body wall tables; E. large body wall table from beneath; F. small tables; G. small tables from side; H. podial plates; I. podial rods; J. ventral end-plate; K. tentacles rods; L. madreporite (different views). (A–K scale a; L scale b)
Specimen small, poorly preserved, eviscerated, most of gut and associated structures lost. Body form subcylindrical, dorsal surface arched, ventral flattened but not much so. Anterior end slightly broader than posterior end. Length
40 mm
, width in mid-body
9 mm
. Colour, in alcohol, white with dark scattered blotches. Mouth anterior, sub-ventral; anus terminal. Podia minute, papilliform, slightly longer ventrally, scattered but with some indication of arrangement in bands. Papillose collar evident. Anus encircled by five clusters of 3– 4 papillae per cluster. Tentacles?18, small, white to slightly beige in colour. Body wall
1 mm
thick, gelatinous, smooth.
Calcareous ring damaged; radial plates squarish, as long as wide, with an anterior notch and some evidence of posterior bifurcations; interradial plates small, triangular, projecting slightly beyond anterior border of radial plates. Tentacle ampullae short; Polian vesicle single, sac-like; stone canal short, free, slightly twisted, terminating in an oval, globular, well-calcified madreporite (
Figure 17L
). Gonad and alimentary canal lost. Right respiratory tree shorter, reaching only half body length, both trees well branched, united at base. Cuvierian tubules absent.
Spicules of body wall comprise tables and buttons. Tables of two sizes: either with a large disc (
42–81 µm
, mean
59 µm
) and a tall spire (
42–68 µm
, mean
53 µm
) (
Figure 17C–E
), or a small disc (
39–65 µm
, mean
54 µm
) and a short spire (
26–39 µm
, mean
32 µm
) (
Figure 17 F
), smaller
type
common at bases of podia. Larger tables of
Mesothuria
type
, disc with mostly undulating or occasionally spinose rim, pierced by usually eight large, oval holes, and sometimes with one or more smaller holes outside the larger ones, spire with 2–3 crossbars, terminating in a ring of several teeth. Smaller table discs somewhat circular, also with about eight marginal holes but a short spire with usually a single cross-bar, margin of disc sometimes turned up giving a cup and saucer appearance to table in lateral view; occasionally tables reduced to button-like discs. Buttons (
Figure 17A
) rare, restricted to bases of podia and anal region, elongate or oval (
45–77 µm
, mean
65 µm
), usually with 3–5 pairs of holes and several knobs, the latter either restricted to the central shaft or to margins or both; buttons sometimes reduced to just two pairs of central holes. Podial deposits comprise small tables, buttons, perforated rods often developed as smooth plates, and end-plates. Podial tables (
Figure 17G
) similar to the smaller
type
from body wall; podial buttons (
45–78 µm
mean
65 µm
), usually heavily knobbed (
Figure 17B
), with 2–5 pairs of holes; rods (
71–113 µm
, mean
91 µm
), straight or slightly curved (
Figure 17I
), with 1–2 holes at ends and/or in the middle; plates with usually irregular margins and 5–10 pairs of holes (
Figure 17H
); end-plates of two sizes, small ones about
148 µm
, large ones (
Figure 17J
) about
187 µm
, both with large central holes and smaller peripheral ones but some peripheral holes often as large as central holes. Tentacle with slightly curved, non-perforated rods (
39–142 µm
, mean
71 µm
), usually with slightly spinose margins (
Figure 17K
). Cloacal and longitudinal muscles without spicules.
Distribution
Known only from
type
locality.
Habitat
Slightly muddy sand, pennatulids.
Remarks
Of the 14 nominal and one indeterminate species currently classified in the subgenus
Theelothuria
, the present specimen comes close to
H. (T.) squamifera
Semper, 1868
from the
Philippines
and the Red Sea and
H. (T.) asperita
Cherbonnier & Féral, 1984
from
New Caledonia
. However, it is not identical to either of the two species. It differs from the former in the height of the table spires, fewer cross-bars to the spires, larger size of the holes on the discs and more nodular buttons, of especially the podia. It differs from
H. (T.) asperita
in the absence of smooth buttons, the larger size of the holes of the discs of the larger tables and the nature of the table crowns. There is also some resemblance of the new species to
H. (Platyperona) insolita
Cherbonnier, 1988
from
Madagascar
, especially in the
type
of tables, their two sizes, and the rarity of buttons. However, Cherbonnier illustrates only smooth buttons with a median optical discontinuity from the anal region of his specimen as well as some minute plates and pseudobuttons. Some reduced tables of the new species resemble those of
H. (T.) klunzingeri
Lampert, 1885
and
H. (T.) notabilis
Ludwig, 1875
but there are gross differences, most notably in the absence of tall-pillared tables in both
H. (T.) klunzingeri
and
H. (T.) notabilis
, suspected by Panning (1935) to be conspecific. It is noteworthy that there are no tack-like tables in the body wall and podia of the new species and although the larger tables are of the synallactid-type, they resemble those of the genus
Mesothuria
rather than those of
Synallactes
.