Leptasterias (Hexasterias) polaris (M̹ller & Troschel, 1842)— Pereira 1997: 336;
Leptasterias polaris (M̹ller & Troschel, 1842)— Micael & Costa 2010: 321.
Type locality: Greenland.
See: Fisher (1930: 60–61, pl. 30, figs. 1, 1a–c, 2, 2a–2d, pl. 32, figs. 3, 3a, pl. 35, figs. 1–3); A.M. Clark & Downey (1992: 441–442).
Occurrence: circumpolar Arctic; in the Atlantic, from Labrador and Greenland south to George’s Bank (Fisher 1930, A.M. Clark & Downey 1992).
Depth: 0–360 m (A.M. Clark & Downey 1992).
Habitat: juveniles and small adults can be found on rocky substrates in shallow water, below lowest water of spring tides; large adults occupy cobble to sandy and muddy areas at greater depths (Rochette et al. 1994).
Larval stage: brooding (Hamel & Mercier 1995).
Remarks: Perrier (1896a) reported L. polaris (as Asterias polaris) from the Azorean rocky intertidal, which later Koehler (1924) re-identifed to Asterias rubens. Later references of this species to the archipelago were based on Perrier’s original report. Nonetheless, the sea surface temperatures in the Azores reach an average minimum of 14°C in the winter (Bashmachnikov et al. 2004) clearly providing an inhospitable environment far too warm to sustain a viable population of this Arctic species (see Hamel & Mercier 1995). The same conclusion can be reached on the possible presence of C. crispatus in the archipelago, i.e. it is unlikely that this stenothermal boreo-arctic species (see Shick et al. 1981) could maintain a viable population in the rocky shores of the Azores.