Ophiacantha bidentata? ( Bruzelius, 1805 )

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 : 34

Ophiacantha bidentata? ( Bruzelius, 1805)

Reports for the Azores:

Ophiacantha bidentata ( Bruzelius, 1805) —? $ Koehler 1898: 55; Koehler 1924: 244–246; Mortensen 1927a: 196, figs. 105.1–2; Nobre 1938: 72; Paterson 1985: 34–36, fig. 15; García-Diez et al. 2005: 49; Micael & Costa 2010: 322; Benavides-Serrato et al. 2011: 244–245; Micael et al. 2012: 3; Smirnov et al. 2014: 195.

Type locality: Norway .

See: Bruzelius (1805: 33, as Asterias bidentata ); Mortensen (1933a: 20–22, figs. 6–8); Martynov & Litvinova (2008).

Occurrence: Arctic (circumpolar) and North Atlantic, from the eastern coast of USA to Greenland and in the eastern Atlantic from South of Iceland to Cape Blanc ( Paterson 1985), including the archipelagos of the?Azores ( Koehler 1898), Madeira ( Jesus & Abreu 1998), Canaries ( Koehler 1906b) and? Cape Verde ( Mortensen 1927a).

Depth: 10–? 4,730 m ( Smirnov et al. 2014);? AZO:? 1,287 m ( Koehler 1898).

Remarks: when describing Ophiacantha fraterna, Verrill (1885c) cautioned that this species had previously been confused with O. bidentata , including some of the H.M.S. Challenger material identified by Lyman (1882). Verrill (1885b) also added that O. bidentata unlike O. fraterna occurs at moderate depths. Later authors consider O. fraterna as a junior synonym of O. bidentata , or a variety of the latter (e.g., Mortensen 1933a; Paterson 1985). As a result, it is difficult to understand the true geographical and depth range of O. bidentata (see discussion by Martynov & Litvinova 2008). In view of this and considering that the report of Ophiacantha bidentata in the archipelago is based on a single poorly preserved specimen collected at a depth of 1,287 m ( Koehler 1898; Hirondelle, sta 112: 38°48’30”N, 28°06’16”W), the inclusion of this species in the Azorean faunal list should be considered with caution.

Mortensen (1927a) included Cape Verde in the geographical distribution of O. bidentata . To the best of our knowledge no animal belonging to this species was ever collected in the archipelago. In an earlier report, Koehler (1906b) recorded this species at Talisman deep-water stations located between off NW African coast and Canaries. It is possible that Mortensen (1927a) mistook Koehler’s records, which was repeated by subsequent references (e.g., Mortensen 1933 a, Nobre 1938, Madsen 1947).