(H. Milne Edwards, 1837)
Diagnosis:
Inner orbital angle with two strong, pointed teeth, which are larger than any of the tubercles on that margin. Inner orbital angle with a toothed lobe which in adults practically touches the outer orbital angle and so closes the orbit. Grooves on the carapace distinct. Lateral margin of the carapace with a cervical incision only. Anterior margin of the carapace between the eye and the anterolateral margin convex. First abdominal somite with three red spots, one rather ill-defined in the middle, and two more distinct laterally; seldom the three are fused to a single broad spot. Outline of posterior margin of the pleura of the second abdominal somite straight or evenly convex. Median carinae present on abdominal somites.
Type:
Type locality of S. squammosus: "Habite L'île-de-France" ( = Mauritius). Type in MP, now lost; there is a dry specimen in good condition in the Paris Museum (Pa 408) from "Ile de France" but it is much smaller than the type, 21.5 cm instead of " 15 pouces" ( = about 37.5 cm).
Type locality of S. sieboldi: "Nagasaki", Kyushu, Japan; in manuscript notes on the type material the collector wrote (in translation) "is caught sometimes in the months of spring in the outer bays near Nagasaki" (see Holthuis and Sakai, 1970: 113). Lectotype male in RMNH, no-D 959.
Type locality of Pseudibacus pfefferi: "Mauritius". Three syntypes in BM, no. 81.7, condition poor.
Type locality of S. australis: "Habitat in Oceano australiori. Mus.Dom.Banks". Type lost.
Geographical Distribution:
Indo-West Pacific region: from East Africa to Japan, Hawaii, Melanesia, New Caledonia and Australia.
Habitat and Biology:
In depths of "a few fathoms" to about 80 m, most common between 20 and 50 m. On reefs and rocky areas. Nocturnal.
Size:
Maximum total body length about 40 cm; carapace length up to about 15 cm.
Interest to Fisheries:
Its large size and well developed fleshy tail make this species, like other species of the genus, a sought-after delicacy. It is scarce and lives in inaccessible places and therefore is not commercially fished. The animals are mostly taken by hand usually at night, but also wire traps are used. They are sold fresh on the local markets.