Holothuria (Cystipus)

Haacke, 1880

10 species

Medium sized forms to 15 cm with flattened body with blunt ends and ventral mouth, surrounded by 20 small tentacles, often completely withdrawn behind the sphincter; anus terminal. Skin rigid from spicules, ventrally small pedicels, completely retractile, dorsally small papillae. Spicules an external layer of tables with knobbed edge and low squat spire with numerous blunt teeth gradually becoming connected with projections from the margins of the disc, resulting in a reticulated hemispherical mass. A crowded layer of regular knobbed buttons, dorsally short with 3 pair holes, in older individuals, some of the buttons becoming gradually almost smooth. Ventral feet with end plate and flat supporting rods or plates with few holes in the ends and along the sides of the central part. Dorsal papillae without end plate or only a vestige, and similar rods or plates. (Deichmann, 1958, for Fossothuria)

Burrowing forms with small ventral tentacles and small ventral feet, with more or less well pronounced dorsal papillae, usually quite distinct along flanks. Skin packed with spicules consisting of an outer layer of clumsy tables with knobbed to spinous disc and a low spire, with a few teeth on top and an inner layer of irregular knobbed buttons with from 3 to 7 pairs of holes, often forming an irregular mesh. Ventral feet with end plate and broad supporting plates with a varying number of holes; in the papillae often a trace of an end plate and usually curved supporting rods. (Deichmann, 1958, for Jaegerothuria)

Tentacles 20; pedicels more or less confined to the ventral ambulacral areas, papillae small and scattered dorsally, and a lateral flange of papillae sometimes evident, anal papillae and collar of papillae around the base of the tentacles not apparent; body wall not very thick, usually about 2 (1-8 mm) often gritty to the touch; body rather vermiform or dorso-ventrally flattened; size small to moderate, up to 200 mm long; calcareous ring fairly stout with radial plates about twice as long as interradial plates; spicules consisting of tables with usually knobbed discs and low spire bearing many short spines which are sometimes so numerous and closely crowded that they may almost obscure the disc or become connected to the knobs on the margin of the disc forming a fenestrated sphere, buttons usually simple with large regularly or irregularly arranged knobs, generally 3-4 pairs, but up to 7 pairs of relatively small holes which may become obscured somewhat by the immensity of the knobs, rarely the buttons modified into fenestrated ellipsoids. (Rowe, 1969)