Parastichopus regalis ( Cuvier, 1817 )

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 : 159

Parastichopus regalis ( Cuvier, 1817)

( Fig. 38 )

Reports for the Azores:

Eostichopus regalis ( Cuvier, 1817) — $ Wirtz & Debelius 2003: 263;

Stichopus regalis ( Cuvier, 1817) — $ Wirtz 2009: 48.

Type locality: Mediterranean Sea.

See: Tortonese (1965: 66–68, figs. 24, 25, as S. regalis ).

Occurrence: Mediterranean Sea and east Atlantic, from the British Islands south to Angola ( Mortensen 1927a, Cherbonnier 1965), including the Azores ( Wirtz & Debelius 2003), Madeira ( Augier 1985) and Canaries ( Perrier 1902); reported elsewhere in the Caribbean and the Gulf of Mexico ( Deichmann 1954).

Depth: 5–800 m ( Tortonese 1965), mostly at depths above 50 m ( Ramón et al. 2010); AZO: 40–275 m ( Wirtz & Debelius 2003, herein).

Habitat: soft sediments (sand to mud; Tortonese 1965).

Commercial value: edible ( Ramón et al. 2010).

Material examined: DBUA-ECH 386 (off Praia da Amora, Ponta Garça, SMG, AZO, 37°42’30”N, 25°20’49”W, 2009.09. 24, 208 m; 1 spm, TL = 136 mm); DBUA-ECH 387 (off Praia da Amora, Ponta Garça, SMG, AZO, 37°42’30”N, 25°20’49”W, 2009.09. 24, 208 m; 1 specimen, TL = 140 mm); DBUA-ECH 390 (off Praia da Amora, Ponta Garça, SMG, AZO, 37°42’31”N, 25°20’14”W, 2011.07. 15, 275 m; 1 specimen, TL = 185 mm).

Description: Body dorsally arched but ventrally flattened, forming a distinct sole with numerous tube feet arranged in three rows (the central one divided in two). Lateral margin separating the ventral and dorsal surfaces of body with large papillae, which is continued anteriorly above the ventrally situated mouth. Ventral surface covered by well-developed conical papillae more or less arranged in longitudinal rows. Body wall relatively thick. Cuvierian tubules absent. Calcareous deposits mostly composed of tables and flattened rods. No buttons. Table disc relatively large, perforated (up to more than 60 holes decreasing in size towards the periphery) and with an irregular round edge; medium high tetrabasal spire with the rods connected by three to five sets of cross bars armed with lateral teeth at its distal part. Rods irregularly perforated. Colour: bivium brown to orange, papillae white or cream; sole with the outer row brown or orange slightly lighter than the bivium, inner double row orange or red. Colour (in ethanol): similar to the live colouration, except for the red and orange colours, which have turned to brown.

Remarks: P. regalis is one of the recent additions to the Azores marine fauna. The absence of this species in the historical collections from the Azores could be explained by the species preferential depth range. The preferred depth spectrum of P. regalis was seldom studied in the archipelago, between the maximum scuba diving (<30–60 m) and the typical depths explored by the oceanographic cruises (> 150–250 m). Also, P. regalis appears to co-occur with Holothuria lentiginosa in the Azores, as both species were capture together among the material dredged off Ponta Garça in S„o Miguel Island (208–275 m depth) during the Third International Workshop of Malacology and Marine Biology. Though with similar colour patterns, these two species can be easily distinguished by the overall body shape, as P. regalis has a well-marked sole ventrally and numerous large white papillae forming a conspicuous lateral rim. In opposition, H. lentiginosa presents fewer dorsal or lateral papillae, which are either dyed dark or of same colour of body surface and is nearly cylindrical without distinct sole.

Figures

FIGURE 38. Parastichopus regalis (Cuvier, 1817) (DBUA-ECH 386). Dorsal view (A, C); ventral view (B, D); specimen, when alive (C, D); ossicles (E).