"Hemigellius bidens (Topsent, 1901)
Figs 63-68
Gellius bidens Topsent, 1901: VII, 1908: 21, pl. I, fig. 1, 1917: 77; Vacelet & Arnaud, 1972: 19; Barthel et al., 1990: 123, 1997: 49.
Haliclona bidens; Koltun, 1964: 100.
Further synonym see KOLTUN (1964).
Material studied. MCNPOR 1981, 1989, St. 4869, Bransfield Strait: 63°33'S-59°15'W, 240 m, 08.11.1986, PROANTAR IV.
Description. (MCNPOR 1989) (Fig. 63) Erect specimen; dimensions, in cm: 4.2 x 1.2, 0.3 thickness. Lightly rugose surface, hispid to the touch. Pores and oscules not observed. Preserved material friable in consistency; colour light brown with clearer regions. MCNPOR 1981 is identical to MCNPOR 1989, only differing in having grey colour; dimensions, in cm: 4.0 x 1.3, 0.4 thickness.
Skeleton. (Fig. 64) Ectosome without specialization, with megascleres in confusion. Choanosome with a reticulation composed by paucispicular tracts (02-03 spicules, 38-54 µm thickness), interconnected by 01-02 spicules, forming some isodictyal meshes (180-520 µm in diameter). Nodal spongin present, microscleres irregular or randomly occurring between the tracts.
Spicules. Megascleres: oxeas - smooth, straight or slightly curved (Fig. 65), acerate extremities (Fig. 66): 440-554.4-660/ 12.5-16.3-18.8 µm (MCNPOR 1981); 480-61 0.4-680/13.8-20.4- 23.8 µm (MCNPOR 1989). Microscleres: sigmas - smooth (Fig. 67), bearing bifid extremities (Fig. 68): 32.5-36.8-40 µm (MCNPOR 1981); 30-35.1-40 µm (MCNPOR 1989).
Remarks. Comparison with measurements provided by TOPSENT (1901) and KOLTUN (1964), the samples here studied have thicker spicules. For the first time the spicules were photographed by SEM, mainly detailing the extremity of the sigmas, which characterizes the species (Figs 67, 68).
Distribution. Antarctica: Bellinghausen Sea (TOPSENT 1901); Graham Land (TOPSENT 1908, 1917); Victoria Land (BURTON 1929, 1938); Wilhelm II Land (1-kmrscim, 1914); Adelie Land (VACELET & ARNAUD 1972); Weddell Sea (BARTHEL et al. 1990, 1997); Bransfield Strait (present study). Bathymetry: 30 m (TOPSENT 1908) to 550 m (TOPSENT 1901)."
(Campos et al., 2007)
