Ceramaster Verrill 1899

Mah, Christopher L., 2022, New Genera, Species and Occurrences of Deep-Sea Asteroidea (Valvatacea, Forcipulatacea, Echinodermata) collected from the North Pacific Ocean by the CAPSTONE Expedition, Zootaxa 5164 (1), pp. 1-75 : 39

Ceramaster Verrill 1899

Tosia (Ceramaster) Verrill 1899: 161

Ceramaster Fisher 1906: 1054 ; 1911: 162, 204; Verrill 1914: 289; Koehler 1924: 173; Mortensen 1927: 80; Djakonov 1950: 38; Tortonese & A.M. Clark 1956: 347; Halpern 1970 b: 62; 1970c: 212; 1970: 62; Downey 1973: 49; McKnight 1973: 178; Downey 1973: 49; A.M. Clark & Courtman-Stock 1976: 61; Clark & Downey 1992: 231; Downey in Clark & Downey 1992: 231; Mah 2011:5 .

Philonaster Koehler 1909: 78 [type species Pentagonaster (Philonaster) mortenseni Koehler 1909 ]

Tosiaster Verrill 1914: 1054 .

Diagnosis (see also comments below). Body outline pentagonal in most (i.e., R/r=1.1–1.5) with some becoming more stellate. Abactinal plates tabulate, granules present on abactinal plates, marginals, actinal plates. Fasciolar grooves present among abactinal, marginal plates. Bare “patch” on dorsal facing of superomarginal plates.

Comments. Ceramaster is characterized by tabulate or weakly tabulate abactinal plates, fasciolar or weakly fasciolar grooves and in several species a strongly pentagonal or weakly stellate body outline and well-defined marginal plates with either complete or partial granular cover. Ceramaster includes approximately 15 species present throughout the world’s oceans, several in the North Pacific. Other more distant species are in general, similar, but show overlap with similar genera such as Peltaster , Sphaeriodiscus and even Mediaster . ( Mah 2011).

Most Ceramaster diversity away from the west coast of North America remains poorly understood as the genus Ceramaster has likely become a paraphyletic assemblage. Some species, such as “ Ceramaster ” (originally Pentagonaster ) cuenoti have been transferred to Pillsburiaster whereas others, such as the Hawaiian Ceramaster smithi , has been transferred to Bathyceramaster (see section herein). Proper delineation of Ceramaster is necessary for identification of unrecognized species and several unpublished but undescribed species of Ceramaster await publication (Mah, unpublished data).

New in situ observations of Ceramaster from the tropical Pacific present new occurrence and in situ ecological data for species in this genus. Apparent observations of uncollected specimens provide further data on diversity within the genus.