Ophiura (Ophiuroglypha) concreta ( Koehler, 1901 )

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 : 57

Ophiura (Ophiuroglypha) concreta ( Koehler, 1901)

Reports for the Azores:

Ophioglypha concreta Koehler, 1901 — $ Koehler 1906b: 261;

Ophiura concreta ( Koehler, 1901) — Mortensen 1927a: 233; Grieg 1932: 32; $ Cherbonnier & Sibuet 1972: 414, 415.

Type locality: Cape Verde (14°47’N, 24°31’45”W) .

See: Koehler (1901: 228–230, figs. 6–8, 1909: 148–149, pl. 25, figs. 3–5, as Ophioglypha concreta ); Paterson (1985: 125, fig. 47, as Ophiura irrorata concreta ).

Occurrence: East Atlantic, from the Bay of Biscay south to Cape Verde, and east to the Azores ( Koehler 1906b, 1909, Cherbonnier & Sibuet 1972); reported as well off South African deep waters ( Paterson 1985).

Depth: 1,885 – 3,120 m ( Grieg 1932, Cherbonnier & Sibuet 1972) AZO: 2,845 –2,995 m ( Koehler 1906b, Cherbonnier & Sibuet 1972).

Habitat: soft substrates (muddy sand; Koehler 1909, Grieg 1932).

Remarks: Paterson (1985) found O. concreta to be identical with O. irrorata in almost every aspect, ascribing no specific value to differences in the arrangement or number of arm spines. In view of this, Paterson proposed to demote this species to a subspecies of O. irrorata , restricted to the East Atlantic. Nevertheless, he also noted that the distinct characters of O. concreta were constant over a wide range of sizes and geographical areas. Martynov & Litvinova (2008) disputed the subspecific division of O. irrorata . According to them, several subspecies should not live syntopically as in the case of O. i. irrorata and O. i. concreta , both known from the Bay of Biscay. Another example of co-existence can be found in Grieg (1932), who identified both forms in the material collected by Michael Sars at a station located north of the Azores (sta 88: 45°26’N, 25°45’W, 3,120 m). However, Martynov & Litvinova (2008) were unsure if they represented two separate species or rather a single polymorphic species. In view of this, we have opted for a more conservative approach and maintain the historical species O. concreta separate from O. irrorata . Presently, O. concreta is known with certainty in the Azores only by historical records of Koehler (1906b; Talisman cruise) and Cherbonnier & Sibuet (1972; Noratlante cruise). See below remarks under Ophiura irrorata .