Holothuria (Lessonothuria) tuberculata, Thandar, 2007

THANDAR, AHMED S., 2007, Additions to the aspidochirotid, molpadid and apodid holothuroids (Echinodermata: Holothuroidea) from the east coast of southern Africa, with descriptions of new species, Zootaxa 1414 (1), pp. 1-62 : 20-22

Holothuria (Lessonothuria) tuberculata sp. nov.

Figure 8

? Holothuria (Lessonothuria) verrucosa Cherbonnier, 1980:637 , fig.12 (A-0), (non H. verrucosa Selenka, 1867 ).

Diagnosis

Medium-sized, cigar-shaped species, holotype 145mm. Podia as conical papillae dorsally and tubefeet ventrally. Tentacles 20, no distinct collar; anal papillae present. Body wall thick, leathery. Polian vesicle single (?two), stone canal single. Table discs spinose to smooth with 8–10 marginal holes; spire of moderate height, terminating in 7–12 teeth. Pseudobuttons mostly irregular, often twisted and/or knobbed or with holes only on one side. Tubefeet with end-plates and other surrounding elongate plates with two series of holes. Table disc diam. 35–85 µm; spire height 20–50 µm; pseudobuttons 20–90 µm; tubefeet plates 130–220 µm.

Type SAM-A27930 , Isipingo , KZN, K. S. Ganga, 24 iv 1978 .

Type locality Isipingo Beach, KZN, rock pool, under stone. Etymology

The specific name is derived from tuberculum (L.) meaning small hump with reference to the conical, wart-like prominences of the dorsal body wall.

Material examined Holotype only.

Description

Specimen cylindrical, 145 mm in length, 29 mm in breadth in mid-body, gradually tapering at both ends. Dorsal and ventral surfaces clearly differentiated but not delimited; dorsal surface, in life, a variegated brown with numerous dark specks, ventral surface pale. Podia differentiated into dorsal papillae, situated on tiny warts, and ventral tubefeet, latter not forming a crowded series but with some indication of their arrangement into distinct bands, at least posteriorly, short, thin, with yellow discs; papillae with reduced discs. Other minute warts with aggregated spicules also present. Mouth ventral; collar inconspicuous. Tentacles 20, short, with yellowish crowns. Anus terminal; anal papillae long, tapering. Body wall tough, leathery, rough to the touch and about 3 mm thick.

Calcareous ring ( Figure 8 J ) small, similar in form to Holothuria pardalis but radial plates 2.5 mm high. Tentacle ampullae extremely short. Polian vesicle single, long, tubular, extending to about a third of body length from anterior end. Stone canal single, short, straight free; madreporite elongate, slightly calcified ( Figure 8I ). Cuvierian organ developed as a spongy mass, probably an aborted or expended structure.

Spicules of body wall tables and pseudobuttons, larger ventrally. Tables ( Figure 8A–D ) usually incomplete, complete ones with usually a spinose disc, 35–85 µm, with 8–10 marginal holes; spire moderate, 20–50 µm high, terminating in a perforated ring of 7–12 unequal teeth. Pseudobuttons ( Figure 8F ) 20–90 µm, mostly irregular, often twisted and/or knobbed or with holes developed only on one side, regular ones with 3–4 pairs of holes. Anal body wall with few elongate, symmetrical pseudobuttons with seven pairs of holes ( Figure 8E ) and tables with smooth, undulating rims. Tubefeet with large end-plates and other surrounding elongate plates, 130–220 µm, with two series of holes ( Figure 8G ). Dorsal and anal papillae without end-plates but with curved, elongate rods, expanded and perforated at ends and sometimes with a third arm ( Figure 8H ). Tentacles with minute rods, smooth or slightly rough at ends.

Distribution KZN, South Africa and New Caledonia.

Habitat Rock pool, in sand.

Remarks

Although the holotype comes close to H. pardalis in its spicules, judging from its size, form, colouration, distinct warts on the dorsum, the distribution and differentiation of podia, general texture and thickness of the body wall and maximum size of the spicules, referring it to H. pardalis is inadmissable. Because of the warts on the dorsum and the form of the spicules the writer was at first inclined to consider it to be referable to H. verrucosa Selenka but the latter species is well characterized by its large size (about 23O mm) and numerous tentacles (about 30) and multiple stone canals and Polian vesicles, although many workers do not report the multiplicity of these structures in the species. The specimen thus appears to be intermediate between H. pardalis and H. verrucosa and not close to any other species within the Lessonothuria group. H. verrucosa , described by Cherbonnier (1980), from New Caledonia has only 20 tentacles, two Polian vesicles and a single stone canal. Hence it is also not identical to Selenka’s species. In fact in its size (l 65 mm), colouration, conical papillae, spicules and the presence of some tables with undulating rims, it appears identical to H. (L.) tuberculata and hence doubiously referred to its synonymy. Other materials, recorded as H. verrucosa , need to be critically examined.

Figures

FIGURE 8. Holothuria (Lessonothuria) tuberculata sp. nov. Holotype. SAM–A27930. A. Tables from dorsal body wall; B. same from side; C. reduced tables from dorsal body wall; D. tables from ventral body wall; E. button from anal region; F. pseudobuttons from dorsal body wall; G. tubefeet plates; H. rods from anal papillae; I. madreporite; J. part of calcareous ring. (A–F scale a; G–H scale b; I–J scale c)