Suberites spermatozoon (Schmidt 1875)

(Fig. 4a–h)

Cometella spermatozoon: Schmidt 1875, p. 116; Pl. 1, fig. 2; Thiele 1903, p. 378, fig. 4.

Suberites spermatozoon: Fristedt 1885, pp. 18–19; Pl. 2, figs. 4a–e; Fristedt 1887, pp. 429–430.

Ficulina spermatozoon: Rezvoi 1928, pp. 82–85, figs. 6–7; Hentschel 1929, pp. 871–872; Burton 1930, p. 496.

Suberites lütkenii var. spermatozoon: Arndt1935, p. 41, fig. 65.

Choanites spermatozoon: Alander 1942, p.79.

Suberites domuncula var. spermatozoon: Koltun 1966, p. 96, fig. 68, Pl. 31, figs. 1–9.

Material analyzed. Kara Sea, PINRO trawl survey, Pomor, 1994, st. 3 (72.417N, 59.4378E), depth 157 m (1 specimen). Boris Petrov, 2000, st. 29 (76.9362N, 85.7631E), depth 71 m, temperature -0.3 °C, salinity 34.3 psu (1 specimen); st. 30 (75.9864N, 83.361E), depth 57 m, temperature 0.2 °C, salinity 33.9 psu (2 specimen).

Barents Sea, PINRO trawl survey, Muklevich, 2003, st. 34 (72.0385N, 33.3903E)), depth 265 m, temperature 2.66 °C, salinity 34.959 psu (7 specimens, KFU-LH-2/009); st. 35 (72.5178N, 33.5017E)), depth 281.7 m, temperature 1.13 °C, salinity 34.926 psu (9 specimens, KFU-LH-2/010); st. 27 (69.581N, 33.1024E), depth 225.1 m, temperature 3.12 °C, salinity 34.501 psu (1 specimen, KFU-LH-2/011). F. Nansen, 2004, st. 72 (75.0026N, 47.0645E), depth 238.7 m, temperature -0.89 °C, salinity 34.965 psu (1 specimen, KFU-LH-2/012). F. Nansen, 2005, st. 1 (73.5092N, 33.5523E), depth 280.57 m, temperature 0.69 °C, salinity 34.996 psu (3 specimens, KFU-LH-2/013).

Description. Sponge pyriform, elongate, more or less laterally compressed, up to 40 mm in length, 5 mm width. The upper parts of the body are rather broad, lobate, sometimes branching, gradually narrowing towards the pedicle (Fig. 4h). Usually there is a single conical osculum on the sponge’s apex. Surface smooth. Consistency is fairly soft, delicate. The color is yellowish (in alcohol).

Spicules. Styles (tylo- and subtylostyles) straight, rather short-pointed (sometimes blunt), of one size class only (W = 0.98, p value = 0.17; Fig. 4a–b 1): 231–401.4±88.5–671.5 × 4.3–7.9±2–12.5 (n = 100) µm. Microxea and microstrongyles centrotylote (not always), slightly spined (sometimes smooth), dimensions 27.3–43±13.7–86.2 (n = 30) µm and 13.3–24±5.6–38.3 (n =30) µm, respectively (Fig. 4c–g).

Skeleton. In pedicle spicules lie along the body axis. The skeleton of main body is confused. Usual bouquets of smaller tylostyles laced with microrhabds are found near the surface.

Remarks. Suberites spermatozoon (Schmidt 1875) is a common arctic shallow-water species found on the shelves of Arctic seas, where it can be quite numerous (Hentschel 1929; Koltun 1966). It is known to inhabit predominantly soft bottoms (Rezvoi 1928), where it has been recorded from 19–500 m (Koltun 1966), in a wide temperature range: -1.8–5 °C.

Specimens of this species were obtained from all across the Arctic, including Greenland and Iceland (Burton 1930), Norwegian cost (Burton 1930; Alander 1942), between Svalbard and Franz Josef Land (Hentschel 1929), from the White (Koltun 1966), Barents (Rezvoi 1928), Kara (Fristedt 1887) and Laptev Seas (Koltun 1966). I have analyzed numerous specimens from the Barents and Kara Seas.