Leptasterias (Hexasterias) polaris (Müller & Troschel, 1842 )

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 : 169-170

Erroneous— Leptasterias (Hexasterias) polaris (Müller & Troschel, 1842)

Reports for the Azores:

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.