Holothuria (Theelothuria)

Deichmann, 1958

14 species

Large spindle shaped forms, up to 20 cm or more, with 20 small terminal tentacles. Conical appendages fairly uniformly distributed in adult specimens; ventrally the appendages ending in a cylindrical soft retractile tube foot, dorsally in papillae. Calcareous ring with remarkably tall radials, slightly excavated posteriorly, forming short tails; interradials as usual. Spicules an outer layer of tables with a circle of marginal holes and blunt upward bent spines, spire low with few teeth, in older individuals tables reduced to irregular, 4 holed plates. An inner layer of irregular buttons with or without a few knobs, in one species buttons gradually become smooth with small holes which tend to become obliterated. Ventral feet with end plate and straight to curved supporting plates with a row of holes along the sides and often a few knobs. In papillae, end plate reduced or lacking and curved rods with fewer holes along sides. Most individuals have a few huge tacklike tables in the appendages, visible to naked eye, consisting of a larger or smaller disc with numerous holes and tapering into a tall conical spire sometimes showing traces of being composed of 4 pillars. (Deichmann, 1958)

Tentacles 18-20; pedicels irregularly arranged on the flattened ventral surface, papillae small to large and conical, irregularly arranged dorsally except for the lateral flange of papillae, and a collar of papillae usually present round the base of the tentacles, anal papillae usually apparent; body wall usually very thin and parchment-like, rarely more than 1 (1-2) mm thick, gritty to the touch, body with a distinctly flattened ventral sole, arched dorsally; size moderate to large up to 250 mm; calcareous ring stout and well developed, radial plates up to twice as long as broad; spicules consisting of well developed tables with smooth or spinose discs sometimes the discs multi armed or synallactid-like, spire either low, moderate or high, usually terminating in a cluster of small spines, some tables with perfectly smooth spire tapering to a pointed apex giving the whole table a tack-like appearance usually present also, buttons either simple with irregular moderate sized knobs or modified into hollow fenestrated ellipsoids. (Rowe, 1969)