Synallactes viridilimus Cherbonnier, 1952

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 : 43-47

Synallactes viridilimus Cherbonnier, 1952

Figure 17

Cherbonnier, 1952: 473, pl. 35, figs. 1-17, pl. 36, figs. 16 & 17.

Type SAM.

Type locality R.V. ‘ Africana’ St. 700C, 32 o 33' S, 16 o 31' E, ca. 530 m.

Material examined

SAM-A28024, R.V. ‘Africana’, West Coast Hake Biomass Survey, St. A 17166-127-091-5028, off Hondeklip Bay , 30 o 37' S, 15 o 18' E, 26.i. 1995, 425 m, 1 spec ; SAM-A28025, R.V. ‘ Africana’ St. CR 059 – St. ‘041’ off Lamberts Bay , ca. 32 o 23.12' S, 16 o 30.23' E, 11.ii.1988, about 450 m, 1 spec.

Description

Specimen SAM-A28024 (ex West Coast Hake Biomass Survey) sub-cylindrical, dorsal surface slightly arched, ventral flattened. Length 150 mm along ventral surface, width in mid-body 30 mm. Colour in alcohol dark greyish-violet dorsally, pale grey ventrally, papillae and tube feet respectively of same colouration. Mouth ventral, tentacles 18, in two circles of 12+6; anus terminal, no special anal papillae but paired terminal podia border proctodaeal membrane. Papillae restricted to dorsal and ventro-lateral surfaces, in six rows, longer in the two ventro-lateral rows, shorter elsewhere, much thicker anteriorly, dorsal to mouth, where they are arranged in four bundles of 3-4 papillae per bundle. Ventro-lateral papillae 2-9 mm long, dorsal papillae 2- 4 mm long, each arising from a wart-like prominence, well supported by spicules. Tube feet restricted to ventral ambulacra, in two zigzag rows in each ventro-lateral ambulacrum and 2-4 also zigzag rows in mid-ventral ambulacrum, with 3–4 rows medially, decreasing to two anteriad and posteriad, stopping 15 mm short of mouth, each tube foot terminating in yellowish sucker, supported by ‘end-plate’. Body wall thin, 2 mm; skin leathery, rough to the touch.

Calcareous ring surrounded by thick membrane, radial and interradial plates not well fused, of equal height, the former with anterior notch, the latter with triangular anterior projection, posterior margin of ring undulating. Polian vesicle single, sac-like, 3 mm; stone canal damaged due to previous dissection. Gonad mature, filling large part of anterior body cavity, tubules long, dichotomously branched once or twice, terminal branchings narrow. Respiratory trees bizarre, remarkably well branched at base, each branch producing several sub-branches, each sub-branch may be sub-divided and/or with sac-like diverticula, giving impression of several trees; left tree longer than right, reaching anterior third of body, right tree slightly shorter but more heavily branched, both trees uniting before opening into cloaca, some branches also arising from common base. Longitudinal muscles unpaired; tentacle and podial ampullae absent.

Spicules of body wall comprise tables of various form and sizes: smaller dorsal tables (crosses) ( Figure 17C ) with 45-100 µm disc, 45-50 µm high spire; smaller ventral tables (crosses)( Figure 17E ) with 50-70 µm disc, commoner, appearing as 3-4 armed bodies; spire high, relative to length of arms, terminating in 3-5 diverging teeth, seldom pierced by a single hole; arms of disc usually branched and sometimes pierced by a single hole; tables with separate pillars rarely encountered. Disc of large dorsal tables ( Figure 17B ) 175-315 µm (mean 226 µm), 3-4 armed, terminating in few (1-3) holes, spire 75-100 µm (mean 89 µm). Disc of large ventral tables ( Figure 17D ) 145-265 µm, also 3-4 armed, arms terminating in 0-4 holes, rarely each arm pierced by a hole at base; spire ca. 100 µm high. Occasionally, arms of tables branching and anastomosing to form complete or incomplete disc, that of dorsal tables ( Figure 17A ) 110-270 µm (mean 206 µm), spire height 80-120 µm; that of ventral tables ( Figure 17F ) 120-155 µm, spire height ca. 75 µm.

Dorsal papillae packed with rods and tables. Rods of three types: simple branched structures ( Figure 17I ) 100-160 µm (mean 136 µm), with or without a spire; elongate rods, 160-985 µm (mean 557 µm), with few spines and no holes at ends; and more elaborate structures ( Figure 17G ) with terminal ends branching and anastomosing, rarely with branches also arising from the middle of shaft. Tables small to large, small tables (crosses) commoner, with 3-4 armed disc, similar to that of body wall; larger tables with 3-armed disc with ramified ends ( Figure 17H ). Tube feet with similar tables ( Figure 17L & J ); rods elongate ( Figure 17K ), 215- 825 µm (mean 603 µm), more spinose but with less elaborate terminal ends; ‘end-plates’ typically synallactidtype, composed of several, closely apposed plates, 630-815 µm. Tentacles deposits ( Figure 17M ) comprise two types of rods: small (60-180 µm), smooth, without perforations at each end, confined to tips, and medium to large rods (245-915 µm) with spinous margins and ends, with 0-3 perforations, confined to stalk and main branches.

Specimen SAM-A28025 (ex St. CR 059) 160 X 30 mm. Colour greyish-violet dorsally and ventrally, faded in some areas. Mouth ventral; anus terminal, tentacles 15 in two circles of 10+5, outer circle of large tentacles, inner circle of much shorter tentacles of varying length, one or two much reduced. Papillae and tube feet as in SAM-A28024, orally about 15, mostly solitary, except those in a bunch of three. No special anal papillae but those of body wall extend in pairs to anus. Spicules as in SAM-A28024, but most in process of corrosion.

Distribution Known only from west coast, WCP, 425- 545 m.

Remarks

Cherbonnier’s (1952) S. viridilimus also came from the west coast of South Africa. The only differences between the present material and Cherbonnier’s type are the number of tentacles, the singularity of the Polian vesicle and the absolute rarity of spires showing discrete pillars. These differences are perhaps individual variations. In fact, in my examination of the type of S. viridilimus at the SAM, I was unable to detect any tables with discrete pillars described by Cherbonnier. The current specimens also come close to S. challengeri Théel , from the subantarctic, especially the description of Massin (1992). Massin describes some complete table discs in his material but, although he re-examined the spicules of the type, failed to find to comment whether such discs are present in the type. However, in my study of the type at the NHML, I failed any tables with complete discs. Théel states that the dorsal papillae in his species are scattered over the ambulacra without any definite arrangement except for the ventro-lateral ones which are arranged in rows. I was unable to verify this as the type is now close to maceration. In any case, Massin (1992) describes their arrangement in rows in his specimens.

Figures

FIGURE 17. Synallactes viridilimus Cherbonnier, 1952. SAM-A28024, A. Tables with complete discs from dorsal body wall; B. large tables from dorsal body wall; C. small tables (crosses) from dorsal body wall; D. large tables from ventral body wall; E. small tables (cosses) from ventral body wall; F. tables with complete discs from ventral body wall; G. branched rods from dorsal papillae; H. large table from dorsal papilla; I. rods from dorsal papilla; J. large table from ventral podium; K. rods from ventral podia; L. small tables from ventral podia; M. rods from tentacles. All drawn to same scale.