Plesiocolochirus, Cherbonnier, 1946

Thandar, Ahmed S., 2018, On some miscellaneous sea cucumbers (Echinodermata: Holothuroidea) in the collections of the South African Museum with three new species, Zootaxa 4532 (1), pp. 57-85 : 62-63

? Plesiocolochirus sp.

( Figure 4 )

Material examined. SAMC-A 090912 , SM 185, off Port Alfred , 33°39.03’ S, 27°11.06’ E, heavy dredge, 90 m, 31 V 1978, 1 spec .

Description. Specimen minute, brittle due to previous drying. Form truncate, anteriorly broad, posteriorly slightly tapered. Length about 5 mm, width in mid-body about 2.5 mm. Colour in alcohol light pinkish to off white. Tube feet in double rows, decreasing anteriad and posteriad, suckers well developed, interambulacra naked. Because of brittle nature of the specimen, number and form of tentacles not examined. Skin thin. Calcareous ring not well calcified perhaps because of juvenility of specimen. Body wall ossicles a superficial layer of baskets and large, knobbed, single-layered perforated plates. Baskets deep, cup-like with cross-shaped base perforated by 4–5 holes and neat, spinous rim, spines short, evenly spaced but varying in size, shorter ones more numerous; length of baskets about 30 µm. Plates elongate, single-layered, knobbed with one end slightly thin and denticulate; holes minute up to 30 or more; length of plates about 300 µm. Tube feet deposits smooth, perforated rods of a variety of form and uneven margins, up to 150 µm.

Remarks. The specific identity of this single, obviously juvenile specimen could not be determined with any degree of certainty; even its generic position is uncertain. It may represent a juvenile of Plesiocolochirus dispar (Lampert) , an east coast form but the lack of any multi-layered plates and buttons in the body wall prevents such a conclusion.

Figures

FIGURE 4. Plesiocolochirus sp. SAMC-A090912. A. Specimen (entire); B. Plates from body wall; C. Rods from tube feet; D. Baskets from body wall.