Hyphalaster inermis Sladen, 1883

Madeira, Patrícia, Kroh, Andreas, Cordeiro, Ricardo, De, António M., Martins, Frias & Ávila, Sérgio P., 2019, The Echinoderm Fauna of the Azores (NE Atlantic Ocean), Zootaxa 4639 (1), pp. 1-231 : 81

Hyphalaster inermis Sladen, 1883

Reports for the Azores:

Hyphalaster antonii $ Perrier, 1885c: 61–64, 1894: 232–235 , pl. 16, fig. 1; Koehler 1909: 29–30;

Hyphalaster parfaiti Perrier, 1885 c—Mortensen 1927a: 52; $ Lieberkind 1935: 19–25, figs. 6–8, pl. 1, figs. 7–9, pl. 3, figs. 1–2, pl. 4, figs. 11–14; $ A.H. Clark 1948: 75;

Hyphalaster inermis Sladen, 1883 — $ Madsen 1961: 58–71, figs. 6–7, pl. 1, figs. 1–14, pl. 2, figs. 1–4, pl. 3, figs. 1–4, pl. 13, figs. 3–4.

Type locality: off Japan ( 34°37’N, 140°32’E), Pacific Ocean .

See: Madsen (1961); A.M. Clark & Downey (1992: 98–99, figs. 18g–i, 19a–b, j, pIs. 26, figs. A–C).

Occurrence: cosmopolitan, in the Atlantic, Pacific and Indian deep water (A.M. Clark & Downey 1992); from the Davis Strait and SW of Greenland ( Madsen 1961), south to Caribbean waters (A.M. Clark & Downey 1992), eastwards in the Mid-Atlantic Ridge ( Dilman 2013) and from the Rockall Trough to Angola ( Sibuet 1975), including the Azores and Cape Verde archipelagos ( Perrier 1894, Koehler 1909); recorded also from the Meteor seamounts ( Madsen 1961, Howell et al. 2003).

Depth: 1,444 –5,430 m ( Dilman 2013); AZO: 2,995 –3,200 m ( Perrier 1894, A.H. Clark 1948).

Habitat: soft substrates, Globigerina ooze, mud to clay ( Koehler 1909, Madsen 1961).

Larval stage: lecithotrophic ( Ramirez-Llodra et al. 2002).

Remarks: Perrier (1885c, 1894) described Hyphalaster antonii based on a single animal collected by Talisman in the Azores (sta 131, 1883: 38°28’00”N, 25°05’46”W, 2,995 m). In the report on the porcellanasterids collected by Danish-Ingolf expedition, Lieberkind (1935) reviewed the type material of H. antonii and established its synonymy with H. parfaiti , thus confirming previous suppositions that the Azorean species might represent a juvenile of the later species ( e.g., Ludwig 1907). Later, A.H. Clark (1948) reported seven specimens of Hyphalaster parfaiti from the archipelago collected by Atlantis (sta 15: 35°37’N, 30°51’W, 3,200 m). In a review of the family Porcellanasteridae, Madsen (1961) placed both Hyphalaster species reported in the Azores in the synonymy of the cosmopolitan Hyphalaster inermis .