Sycettusa Haeckel, 1872

Borojevic, Radovan & Klautau, Michelle, 2000, Calcareous sponges from New Caledonia, Zoosystema 22 (2), pp. 187-201 : 197

Genus Sycettusa Haeckel, 1872

TYPE SPECIES. — Sycetta (Sycettusa) stauridia Haeckel, 1872 by monotypy.

DIAGNOSIS. — Heteropiidae with a syconoid organization. Atrial and cortical skeletons are formed by tangential triactines and/or tetractines. The choanoskeleton is inarticulate, and is composed of unpaired actines of the subatrial triactines, and of centripetal actines of the pseudosagittal subcortical triactines.

DESCRIPTION

We propose splitting the genus Grantessa (in the scope defined by Dendy & Row 1913) into two groups: one with the inarticulate choanoskeleton, named Sycettusa and the other with the articulate one, named Grantessa . The former has potentially evolved by corticalization of sponges with an inarticulate skeleton similar to the sponge described in New Caledonia under the name Grantessa syconiformis Borojevic, 1967 .

In the Indo-Pacific region, the genus Sycettusa includes S. stauridia Haeckel, 1872 , S. (Grantessa) glabra (Row, 1909) and S. (Grantessa) hastifera (Row, 1909) from the Red Sea; S. (Grantessa) simplex (Jenkin, 1908) from Zanzibar; S. (Sycortis) sycilloides (Schuffner, 1877) from Indonesia and S. (Amphoriscus) poculum (Poléjaeff, 1883) from Australia.

Haeckel (1872) proposed the subgenus Sycettusa for the single species S. stauridia from the Red Sea, which is a typical syconoid Heteropiidae with an inarticulate choanoskeleton. We retain the same combination at the genus level, and consider S. stauridia to be the type species of the genus.