Mesothuria rugosa Herouard 1912

Mesothuria rugosa Hérouard, 1912 Reports for the Azores:

p.p. Mesothuria murrayi (Théel, 1886) — $ Hérouard 1902: 23–24;

Mesothuria rugosa Hérouard, 1912 — $ Deichmann 1930: 98–99, pl. 8, figs. 1–6.

Type locality: off Cape Verde (16°12’30”N, 24°43’45”W).

See: Hérouard (1912: 1–3, fig. 1; 1923: 19–21, pl. 1, figs. 11–21, pl. 2, figs. 1, 2); Deichmann (1930); Benavides-Serrato et al. (2012: 206); Gebruk (2012: 308–309, figs. 9, 12).

Occurrence: North Atlantic, from Caribbean waters eastwards to the Azores and Cape Verde (Hérouard 1912, Deichmann 1930).

Depth: 460– 3,890 m (Benavides-Serrato et al. 2012); AZO: 1,600 m (Hérouard 1902).

Habitat: soft substrates (Hérouard 1902).

Remarks: Deichmann (1930) re-examined one of the two specimens collected by Princesse Alice southeast of Flores Island (sta 719: 39°11’00”N, 30°24’15”W, 1,600 m) and identified by Hérouard (1902) as Mesothuria murrayi. She compared with her specimens of M. rugosa from the Caribbean waters and found them to be identical. Considering the intricate taxonomy of this species together with other closely related species such as M. maroccana and M. murrayi, some authors have expressed doubts about the validity of this species (e.g., Gebruk 2012). However, present knowledge on the intraspecific variation in these species is still scarce and thus an extensive revision on these species is pending.