Description: Growth form: An erect pedunculate ‘ crinorhiza’ form sponge with a subspherical body bearing long tentacular processes, supported by a long thin stem, terminating in long bifurcated root-like anchor processes. The body often has an apical nipple, or tuft of mycalostyles (Figure 18 B). Specimens range from 40 – 44 mm long, with subspherical body 6 – 9 mm diameter, tentacular process 9 – 26 mm long, 0.2 – 0.6 mm diameter, the stem is a tapering cone 1.5 – 7 mm in diameter and 3 – 9 mm in length, basal root processes 16 – 27 mm long, 0.2 – 0.5 mm diameter. Antarctic specimen SAMA S 313 is a maximum of 56 mm long, with subspherical body 16 mm diameter, tentacular process 11 mm long, 0.3 – 0.5 mm diameter, the stem is 1 mm in diameter and 35 mm in length, and has no basal root processes. Another Antarctic specimen SAMA S 3575 has a total length of 26 mm, with the stem 18 mm in length and 1 mm in diameter, a subspherical body of 18 mm in diameter, also with no basal root processes. The remainder of the tentacular processes are only a maximum of 1.5 mm in length. This species has been well described by previous authors and matches with previous descriptions. Colour: Light brown with white stalk, light yellow to tan with ectosome removed. Ectosomal skeleton: The ectosome consists of a crust of isochelae and sigmas (Figures 19 A – D). In the body of the sponge this is penetrated by the smaller mycalostyles from the ectosome producing the hispid surface (Figure 19 B). Endosomal skeleton: The endosome in the body consists of the radially orientated bundles of large mycalostyles that form the filaments. Subectosomally there is a confused predominantly radial assortment of the smaller mycalostyles penetrating through the ectosome to the surface. The endosome also contains the isochelae and the sigmas (Figure 19 A). The endosome of the filaments consists of the parallel mycalostyles in an extremely well organised bundle (Figure 19 C – D). The endoosome of the stem and root processes also consist of a tightly bound longitudinally orientated mycalostyles. Megascleres: Styles in two categories, large mycalostyles (916 – 2820 x 20 – 50 µm), and thinner supporting styles (387 – 1190 x 5 – 19 µm), (see Table 11). The large mycalostyles occur in the stem, the body and the filaments. The smaller styles occur mainly in the body radially orientated and penetrating the ectosome producing the hispid surface of the body, but also occur in the filaments and the stem and roots. These styles could also be described as a continuous range of the one type, as was probably done in the original description. Microscleres: Tridentate unguiferate anchorate isochelae (20 – 65 x 2 – 7 µm) in two sizes, but with intermediate sizes, and sigmas (39 – 75 x 1.5 – 3 µm) (see Table 11). Molecular data: The 28 S sequence of QM G 337490 is provided in the Sponge Barcoding Database under accession number SBD # 2307 and the molecular difference to other congenerics displayed in Figure 3.
