FAO Species Identification Guide for Fishery Purposes Western

1190 Holothurians
Thelenota anax Clark, 1921
Frequent synonyms / misidentifications: None / None.
FAO names: En - Amber fish.
calcareous ring
spicule of papillae
anus with
5 teeth
spicules of tegument spicules of podia
(after Féral and Cherbonnier, 1986)
conical papillae
spicules of tentacles
mouth ventral,
with 18 brown
tentacles
large row of papillae between
bivium and trivium
Diagnostic characters: Body firm, rigid, squarish in cross-section, flattened ventrally (trivium). Bivium
entirely covered with numerous characteristic, conical papillae and minute podia; bivium demarcated
from the trivium by a row of large papillae. Podia numerous on trivium, with large disc, about 600 µm in
diameter. Mouth ventral, surrounded by a circle of 18 large brown tentacles. Anus terminal. Calcareous
ring with large radial pieces and narrow interradials. Cuvierian tubules absent. Cloaca large. Colour: bivium
cream, with large beige dots; trivium generally beige; mature gonads deep purple. Spicules: tegument with
branched spicules showing polygonal holes, and spicules in form of a “rose window”, mostly abundant in
the tentacles; tentacles also with straight, curved, or X-shaped rods; ventral podia with short, smooth rods;
dorsal papillae with sparse, very long, spiny rods.
Size: Maximum length about 80 cm, commonly to about 55 cm; mean live weight about 3.5 kg (up to 6 kg);
body-wall thickness about 15 mm.
Habitat, biology, and fisheries: A rare reef species, mostly found at depths between 10 and 30 m;
generally occurs on hard grounds, large rubbles and sand patches, on reef slopes, outer lagoon and near
passes. Populations not reaching high densities, with a mean of around 0.001/m 2. Biology poorly known.
Rarely harvested until few years ago, being generally found in low densities. Collected by skin diving or
using diving gear (if not banned), making the populations presently very vulnerable, due to overexploitation.
The processed product is probably of low to moderate commercial value and the exploitation of this species
should be avoided.
Distribution: In the tropical
Indian Ocean known from the
Glorieuses Islands; in the
tropical Pacific, from northern
Australia to Enewetok, Guam,
the China Sea, and the Ryukyu
Islands southwards to New
Caledonia, Fiji, and the Society
Islands.
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