Calocidaris fusca Mortensen 1939 (see remark below)

Family: Cidaridae-Cidarinae

Order: Cidaroida

Locality: Philippines, Siquijor, 250-300 feet, 2006

Dimensions: 25 mm Ø,
longest spine 66 mm


Mortensen remarked to the genus Calocidaris in his Monograph of the Echinoidea, I, Cidaroida, 1928, p. 312: "Differs from Cidaris only in the character of the primary spines, which are cylindrical, perfectly smooth and shining without the slightest trace of hairs."

The only known species in that time was Calocidaris micans Mortensen , reported from the West Indies, Barbados and Cuba in depths from 200 to 330 m.

As I learned from The Echinoid Homepage ( later on two more species have been detected with smooth and glabrous spines, namely Calocidaris fusca Mortensen from the Indo-Pacific. But Calocidaris fusca is a little confusingly linked on this page to Lissocidaris fusca Mortensen, this species having cortical hairs on the spines. The author A. B. Smith has some doubt, if this difference is of generic value.

Finally, in "Sea Urchins" from Heinke Schultz, p. 30, three species are mentioned for Calocidaris (primary spines smooth, Indo-Pacific, Carribbean), but unfortunately without any details (probably not shallow water species).

As the only other genus with smooth spines Homalocidaris is restricted to antarctic waters, I think, Calocidaris fusca is the most probable species (at least as long as anyone else has not a better idea).