Zoroaster fulgens Thomson 1873

Zoroaster fulgens Thomson, 1873 Reports for the Azores:

Zoroaster longicauda $ Perrier, 1885c: 19–21; Mortensen 1927a: 131;

Prognaster grimaldii $ Perrier, 1891: 259–262, 1896a: 23–25, pl. 2, figs. 1, 1a, 1b;

Prognaster longicauda $ Perrier, 1894: 120–125, pl. 10, fig. 1;

Zoroaster fulgens Thomson, 1873 — Sibuet 1975: 108; $ Dilman 2008: 147.

Type locality: Faroe Channel (lectotype).

See: Downey (1970: 15–17); A.M. Clark & Downey (1992: 403–404, figs. 61c–d, 67a, pl. 96, figs. G–H); Benavides-Serrato et al. (2011: 204–205).

Occurrence: Atlantic Ocean, from Newfoundland south to Brazil, eastwards from south of Iceland and the Faroe Channel south to Angola (Sladen 1883, Grieg 1932, Sibuet 1975), including the Azores (Perrier 1894), Canaries and Cape Verde (Koehler 1909).

Depth: (?120) 220– 4,810 m (Grieg 1932, Gage et al. 1983, A.M. Clark & Downey 1992); AZO: 2,870 –3,050 m (Perrier 1891, Dilman 2008).

Habitat: soft substrates, ooze, muddy sand, sand to gravel (Farran 1913, Sneli 1999).

Larval stage: lecithotrophic (McEdward & Miner 2001).

Remarks: Zoroaster fulgens presents a high degree of variation throughout its geographic and depth range and was described under several synonyms and varieties (see Downey 1970). Historically, the presence of this species in the Azorean waters was recorded under the names Zoroaster longicauda (= Prognaster longicauda; Perrier 1885c, 1894; Talisman) and Prognaster grimaldii (Perrier 1891, 1896a; Hirondelle). Both species were known only from the material described by Perrier and in the latter case was known only from the Azores. A.M. Clark & Downey (1992) reunited all specimens attributed to the genus previously under the name Z. fulgens, including the two Azorean species. Nevertheless, Downey (1970) noted that Z. fulgens from the northern part of its range tends to be more spinose and more robust and is generally found below 1,830 m. In contrast, on southern part of its range, this species can be found at depths as shallow as 365 m and tend to have a more compact skeleton, less spinose and slender arms. In turn, Howell et al. (2004) identified three depth related morphotypes in Porcupine Seabight (SW of Ireland): a robust form (925– 1,750 m), a slender form (1,300 –2,200 m) and a long-armed form (3,300 –4,020 m). Genetic analysis revealed that these forms are reproductively isolated, and the shallower robust morphotype might represent a distinct species. The known depth range of Z. fulgens in the Azores is between the depth intervals recorded by Howell et al. (2004) for the two deeper forms. The arm length/disc radius ratio presented by Perrier (1894, 1896a) for Z. longicauda (from 2995 m depth) and for P. grimaldii (from 2870 m depth) were respectively 16 and 15, both well above the 9.7 given by Howell et al. (2004) for the long-armed form. More recently, Dilman (2008) reported material belonging to Z. fulgens collected by G.O. Sars (MAR–ECO cruise) from in northern Azorean waters depths between 2954 and 3050, but gave no descriptions.