Holothuria (Lessonothuria) lineata, Ludwig, 1875

Thandar, Ahmed S., 2008, Additions to the holothuroid fauna of the southern African temperate faunistic provinces, with descriptions of new species, Zootaxa 1697 (1), pp. 1-57 : 53-54

H. (L.) lineata Ludwig, 1875

Figure 20

Holothuria lineatea Ludwig, H. 1875 (2): 77-120, pls. 6, 7.

Holothuria (lessonothuria) lineata Rowe (in Rowe & Gates, 1995):291.

? Holothuria (Lessonothuria) insiginis Thandar 2007 (1414) :1-62 (16, text-fig. 6).

Material Examined SAM-A28028, St. T.V., off Castle Rocks, False Bay , D. Herbert, scuba-dive, xi.1988, 5- 12 m., 1 spec.

Description

Specimen juvenile, 25 x 9 mm, dorsal surface arched, ventral less so. Mouth and anus terminal, collar absent, anus encircled by 15 papillae. Tentacles minute, transparent. Podia in 2-4 rows per ambulacrum ventrally and two rows dorsally, a few also in interambulacra. Colour in alcohol off-white. Body wall <1 mm thin, indicating accumulation of spicules in heaps. Calcareous ring ( Figure 20K ) under-developed, almost ribbonlike, radial and interradial plates of more or less equal height, the former wider, notched anteriorly, the latter with blunt anterior projection. Longitudinal muscles paired, anteriorly split.

Spicules of body wall comprising tables and pseudobuttons. Tables ( Figure 20E ) scarce, with smooth to spinose disc, 39-65 µm (mean 52 µm), pierced by four central and 2-12 marginal holes, often incomplete ( Figure 20D ) with reduced/rudimentary spire, occasionally turned up to give cup and saucer appearance to table ( Figure 20A ) in lateral view; spire 16-19 µm (mean 18 µm), of four pillars without cross-bar, terminating in a perforated crown of few blunt teeth. Pseudobuttons ( Figure 20F ) numerous, accumulated in heaps, 29-58 µm (mean 43 µm), usually complete, smooth, with 2-5 pairs of holes, sometimes incomplete, especially ventrally, with holes developed only on one side, rarely twisted. Podia with tables, minute non-perforate rods ( Figure 20A ) branched at ends and/or in the middle, larger perforated rods ( Figure 20C ) and smooth multilocular plates ( Figure 20B ) with irregular margins and two large central holes; end-plates present. Anal papillae with small, reduced tables ( Figure 20H ), 26-39 µm (mean 31 µm), slightly curved rods ( Figure 20I ), 61-136 µm (mean 100 µm), with or without terminal perforations, and much-reduced end-plates ( Figure 20J ). Tentacle deposits as slightly curved rods ( Figure 20G ), 58-158 µm (mean 95 µm), spinulated and/or digitated at ends which occasionally bear a single hole. Longitudinal and cloacal muscles without spicules.

Habitat? Sub-tidal kelp forest, rich soft coral.

Remarks

Judging from its size, distribution of podia and immaturity it is certain that the specimen is juvenile. The distribution of podia and the ribbon-like form of the calcareous ring led to the initial description of the specimen as a Labidodemas , a genus recently revised by Massin et al. (2004). However, Rowe, one of the reviewers of the M.S., suggests that the specimen might represent a Lessonothuria , perhaps H. (L.) lineata . I respect his judgment, moreso that the specimen was at first identified as a Lessonothuria but described as a Labidodemas because of the form of the underdeveloped calcareous ring. The specimen fits well the description of H. (L.) lineata , a species recently resurrected from the synonymy of H. (L.) pardalis by Rowe (in Rowe & Gates 1995), after study of various type materials. It is well characterised by the presence in the ventral podia of elongated, multilocular plates with jagged margins. In fact, several similar South African forms from the east coast were recently referred to H. (L.) insignis Ludwig by the writer ( Thandar 2007), based on the resem- blance of their spicules to those illustrated by Ludwig (1875). Since these specimens also possess the characteristic ventral podial plates of H. (L.) lineata , it is here suggested that this material may also represent H. (L.) lineata . Nevertheless, the frequent development of holes on only one side of the pseudobuttons in H. (L.) insignis , as illustrated for by Ludwig (1875), Thandar (2007) and others, still questions the treatment of this species as a synonym of H. (L.) pardalis , although Rowe (in Rowe & Gates 1995) did examine two syntypes of the former species.

Figures

FIGURE 20. Holothuria (Lessonothuria) lineata Ludwig, 1875. Juvenile. SAM-A28028. A. Branched rods from podia; B. plate from podium; C. perforated rods from podia; D. developing tables from body wall; E. tables from body wall; F. buttons from body wall; G. rods from tentacles H. tables from anal papillae; I. rods from anal papillae; J. end-plate from anal papillae; K. calcareous ring. A-J scale a.