Atheraster pheos, Mah, 2023

Mah, Christopher L., 2023, New Goniasteridae and in situ observations significant to deep-sea coral predation, Memoirs of Museum Victoria 83, pp. 1-35 : 5

Atheraster pheos n. sp., Atheraster luma n. sp., Atheraster symphonia Mah 2022 , Atheraster umbo n. sp

Comments. Atheraster symphonia and Circeaster arandae Mah 2006 exhibit acutely larger abactinal arm plates than those on the disk and large conical spines on marginal plates ( Mah, 2022). Occurrences are described from the Musician Seamounts in the North Pacific, and Madagascar and New Caledonia, respectively. Although the abactinal surface is not covered by granules, the prominent marginal plate spination, pedicellariae and elongate arms are similar to the hippasterine Evoplosoma . Overall body shape, including the tapering arms, the marginal plate spination and the numerous actinal pedicellariae, is also similar to Armaster nov. gen.

Imagery from the NOAA ship Okeanos Explorer has permitted numerous observations of Atheraster , including at least two apparent observations of undescribed species from the Pacific and the Atlantic (e.g. Mah, 2022 and in preparation), which were not collected.

Key to Atheraster species

(0) Marginal plates with strongly arched tumescence present on superomarginal arm plates, more weakly developed on inferomarginals. Atheraster umbo n. sp.

(0’) Marginal plates with a well-developed, pointed or conical spine present on most marginal plates, especially on the arm. Interradial or disk plates with a single spine or smaller, more variable spines or granules. (1)

(1) Coarse, prismatic granules present in abundance on abactinal plate surface or forming periphery around each plate. Atheraster symphonia Mah 2022

(1”) Granules absent from abactinal plate surface. Peripheral granules around abactinal plates, widely spaced. (2)

(2) Interradius with multiple conical pointed spinelets. (3)

(2’) Interradius with a single prominent spine. Atheraster luma n. sp.

(3) All marginal plates, arms and interradii with spinelets. No single spines. Atheraster pheos n. sp.

(3’) Spinelets present interradii, single spines present along arms. Atheraster arandae ( Mah 2006)