Mesothuria milleri Gebruk & Solís-Marín, in Gebruk et al., 2012

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 : 155

Mesothuria milleri Gebruk & Solís-Marín, in Gebruk et al., 2012

Reports for the Azores:

non Holothuria verrilli Théel, 1886 b— $ Marenzeller 1893: 7–9, pl. 1, fig. 2, pl. 2, fig. 2 [misidentification]; non Allantis intestinalis verrilli Théel, 1886 b— $ Hérouard 1902: 18–21, pl. 1, figs. 3–6 [misidentification]; non Mesothuria verrilli Théel, 1886 b— $ Perrier 1902: 307–312, figs. 3–4, pl. 16, figs. 22–31 [misidentification]; $ Hérouard 1923: 10–13 [misidentification]; Mortensen 1927a: 381–382, figs. 224.4–5; Deichmann 1930: 93–94, pl. 6, figs. 1–8; No- bre 1938: 152; Harvey et al. 1988: 184; Pérez-Ruzafa et al. 1992b: 144; García-Diez et al. 2005: 51 [all these are based on previous misidentifications]; Mesothuria milleri $ Gebruk & Solis-Marin, in Gebruk et al., 2012: 274–283 , fig. 4; Gebruk et al. 2014: 170.

Type locality: Porcupine Seabight, NE Atlantic (51°31’06”N, 12°59’00”W).

See: Gebruk (2012).

Occurrence: Northeast Atlantic, from Iceland and the Rockall Trough south to West Africa, including the archipelagos of the Azores and Canaries ( Gebruk et al. 2012).

Depth: 455– 4,400 m ( Gebruk et al. 2012), most common between 1,430 and 1,530 m ( Gebruk et al. 2014); AZO: 1,258 –2,155 (?3,018) m ( Gebruk et al. 2012).

Habitat: soft substrates (mud; Perrier 1902).

Larval stage: lecithotrophic ( Gebruk et al. 2012).

Remarks: Gebruk et al. (2012: 281) reviewed the historical material identified as M. verrilli ( Théel, 1886b) from the East Atlantic, and concluded that, due to the incomplete initial description by Théel, this Caribbean species was historically confused with other similar species, particularly with M. intestinalis ( Ascanius, 1805) . Moreover, Gebruk and co-authors found a third new species among the historical material, which they described as M. milleri . The re-identified specimens by Gebruk and co-workers included specimens from Talisman taken within Azorean waters and previously identified by Perrier (1902) as M. verrilli . Additionally, by examining animals of different sizes, Gebruk et al. (2012) characterized different ontological trends in each species ossicles, and recognized M. milleri in the descriptions by Marenzeller (1893) and Hérouard (1902, 1923). Both authors recorded M. verrilli from the Azores (see also remarks under M. intestinalis ).