Crossaster Müller & Troschel, 1840a

Mah, Christopher L., 2023, New Genera, Species, and observations on the biology of Antarctic Valvatida (Asteroidea), Zootaxa 5310 (1), pp. 1-88 : 44-45

Crossaster Müller & Troschel, 1840a

Crossaster Müller & Troschel, 1840a: 103 ; 1840b: 318; Perrier 1875:272; Agassiz 1877: 98; Viguier 1879: 138; Bell 1881a: 140; Danielssen & Koren 1882: 51; Perrier 1896: 40; Fisher 1911: 389; Verrill 1914: 258; Fisher 1916: 447; Hayashi 1939: 297; 1940:186; Djakonov 1950: 71; H.E.S. Clark 1963: 55; Clark & Downey 1992: 296; McKnight 2006: 13.

Solaster (Polyaster) Gray 1840: 183 .

Solaster (part) Fisher 1911: 389.

Diagnosis

Arms 8–15, disk broad. Abactinal skeleton openly reticulate with elongate paxillae, widely spaced. Spinelets pronounced and brush-like. Single series of marginals forming distinct periphery. Actinal plates confined to disk. (modified from Clark & Downey 1992)

Comments

Crossaster is a genus containing 10 species ( Mah 2021) from cold-water and temperate water settings, including six species from Northern Hemisphere boreal habitats, one deep-sea species from the central Pacific and 3 species from high-latitude settings in the Southern Hemisphere. The North Pacific/North Atlantic species Crossaster papposus ( Linnaeus, 1767) shows predatory habits with a wide range of prey, including gastropod and bivalve mollusks, cnidarians, and echinoderms ( Jangoux 1982). Little is known regarding other Crossaster species although their feeding habits are likely comparable to those of Crossaster papposus .

Historically, three species of Crossaster are reported from Southern Hemisphere high-latitude settings, Crossaster penicillatus Sladen, 1889 from South Africa and adjacent southern Indian Ocean settings (A.M. Clark 1962) and two South Pacific species, Crossaster campbellicus McKnight, 1973 and Crossaster multispinus H.L. Clark, 1916 , which is also reported from the Kermadec Islands, the Campbell Plateau, and southeastern Australia ( McKnight 2006).

Herein, a further South Pacific species is described and another is synonymized.

Key to Crossaster species at High-Latitudes

(0) Abactinal paxillae, 20–40, inferomarginal paxillae each with 10–20 spines. Actinal plates bearing 10–15 spines.............................................................................................. Crossaster taitai n. sp.

(0) Abactinal paxillae, 2–18 (mostly 2–5), inferomarginal paxillae with spines 8–30. Actinal plates with 2–4 spines.......... (1)

(1) Subambulacral spines, 3–5 mostly 3–4. Superomarginals present, similar to abactinal paxillae and placed just above inferomarginals. Known only from New Zealand............................. Crossaster campbellicus McKnight, 1973

(1’) Subambulacral spines 5 to 8, mostly 7–8. Small ovoid superomarginals plates alternating with larger inferomarginals. Known from South Africa, Indian Ocean, Australia, New Zealand......................... Crossaster penicillatus Sladen, 1889