Geodia barretti , Bowerbank 1858

Geodia cf. barretti Bowerbank, 1858

Figure 2; Table 1

Geodia barretti, Bowerbank, 1858: p. 290.

Cydonium barretti, Gray, 1867: p. 548.

Sidonops barretti, von Lendenfeld, 1903: p. 101

Geodia simplicissima, Burton, 1931: p. 2

Material examined. NCPOR /HYD-CIO/0011, unnamed seamount 265 km southwest of Rodrigues Triple Junction, Southwest Indian Ridge, - 26.4835°S, 67.41°E, depth 2236 m, modified benthic sledge, collected by Dr. Baban Ingole, 11 April 2019; UPSZMC 190804, two spicule slide preparations of the same specimen.

Comparative material. Geodia barretti, holotype, BNHM 1877.5.21.1399, South side of Vikna Island, North- Trøndelag, Norway, 183 m, coll. R. McAndrew; Geodia hentscheli, holotype, ZMB Por 7549, North of Spitsbergen, 81°20′N, 20°30′E, 1000 m, 11 th August 1898; Geodia garoupa, holotype, MNRJ 7349, Campos Basin, RJ, Brasil, 22.366°S, 39.893°W, 1130 m, 7 Feb. 2003, coll. RV Astro Garoupa.

Description. A small, damaged presumably previously subspherical sponge (Fig. 2A), 20 × 10 × 30 mm in diameter, growing on a rock (Fig. 2A). The sponge is firm and hard but compressible. Most of the surface has been removed during collection but it appears prickly with spicules protruding 1 mm (Fig. 2A) where the ectosome layer is still visible. Oscules and pores are not visible. Cortex 0.8–1 mm thick where visible (Fig. 2B). Colour in life beige, with cortex whitish; in ethanol whitish beige.

Skeleton (Fig. 2B). Ectosomal skeleton with oxeas II protruding the surface (Fig. 2B). Layer of strongylasters followed by a layer of sterrasters. Triaene cladomes support the cortex. Oxyasters and sterrasters are present in the choanosome.

Spicules (Fig 2C–I; Table 1). Megascleres. Oxeas I (Fig. 2D), large, usually bent, 2991 (2461–3774) μm × 58 (46–71) μm. Oxeas II (Fig. 2D), straight, 672 (518–897) μm × 9.5 (8–11) μm. Ortho- to dichotriaenes (Fig. 2C) with a wide size range, most are dichotriaenes, rhabdome with tapering tips and commonly with one to two ectopic branches, bent up (Fig. 2C), rhabdome: 2934 (1824–3494) μm × 114 (92–148); cladome structures vary, with the clad tips either bent down or bent inside or straight, clad tips are commonly slightly dichotomized, orthoclad, 250 (181–345) μm; protoclad, 170 (118–233) μm; deuteroclad, 201 (115–265) μm. Anatriaene, one found on slide UPSZMC 190804, rhabdome broken,> 1264 µm × 30 µm; cladome fairly opened, clad 136 µm.

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TABLE 1. (Continued)

Microscleres. Oxyasters (Fig. 2I), one category, approximately 13 spiny slender actines, 28 (25–31) μm in diameter. Sterrasters (Fig. 2E, F), spherical to oval (most are spherical), 106.7 (95–120)/111.6 (100–121) μm in length/width, warty rosettes with 6–9 cylindrical rays (Fig. 2G). Strongylasters, with 12–15 actines, spined at the extremity, 11 (11–12) μm in diameter (Fig. 2H). Much larger and elongated sterrasters (186–198 x 151–160 µm) were also found on slides UPSZMC 190804 but they were considered to be contamination of another Geodia.

DNA sequence data. MT806154 (COI); OP328304 (28S); MT791489 (18S).