Ceramaster grenadensis

Ceramaster grenadensis (Perrier, 1881)

Figures 6 B–D

This species was identified based on the abactinal tabulae on the surface as well as the darkened central surface regions on the superomarginal plates which broadly corresponds to the morphological definition of Ceramaster grenadensis from this region. This is a widely occurring species [Clark and Downey (1992)] and shows variable characters, including marginal plate number, decoration and shape, body form as well as abactinal and furrow spination. Clark and Downey (1992) argue for species, such as Ceramaster patagonicus as a subspecies of Ceramaster grenadensis. Their determination has not been widely accepted (e.g., Mah 2011).

Feeding Observations

The first Richardson Scarp observation at 954 m shows an individual hunched over dead coral rubble, likely feeding on the brown epizoic organisms on the surface. The second Richardson Scarp observation at 897 m shows an individual with two possible sponge stalks or other fragments emerging from below the oral surface.

Worm Association

One observation of this species in Okeanos Ridge at 734 m showed an individual with a yellow polynoid polychaete present on its abactinal surface.

Occurrence: Florida to Northern Brazil, Azores, Southwest Ireland to the Gulf of Guinea, the Mediterranean. 200– 2500 m.

Images Examined

with worm. Okeanos Ridge, 25.67993, -84.62042, 734 m

EX1711_IMG_20171202T143855Z_ROVHD.jpg

feeding-coral skeleton. Richardson Scarp, North Atlantic. 32.09334, -77.16114, 954 m EX1806_IMG_20180622T153725Z_ROVHD.jpg

Richardson Scarp, North Atlantic. 32.09346, -77.16175, 897 m EX1806_IMG_20180622T172206Z_ROVHD.jpg