Pentaceraster Doderlein 1916

Genus Pentaceraster Döderlein, 1916 Type: Asterias mammillata Audouin, 1826, by priority Diagnosis: Since it was established, it has been noted that Pentaceraster is problematic (Döderlein 1936; Clark & Rowe 1971) and particularly difficult to diagnose from the closely related genus Pentaster Döderlein, 1935. Although we are confident in the identification of Pentaceraster mammillatus below, the following generic diagnosis should not be treated as definitive. A full taxonomic revision of the genera is outside the scope of this study. Arms typically 5, well-developed, tapering to rounded points along distal half, interradial areas extensive. Primary radial plates typically crowned with high, conical prominences. Aboral skeleton reticular with secondary plates linking larger primary ones, leaving large well-defined pore-filled areas between, although these are not well developed as in Poraster Döderlein, 1916. Primary plates armed with evenly spaced conical tubercles, prominent on rays and at nodes between plates. Body not completely covered in low rounded warts on primary and secondary plates as in Pentaster Döderlein, 1935. Distal marginals and other plates covered with even sized, distinct, usually projecting granules. Actinal plates typically with some of the central granules elongated into short spines.