Antarctoscyphus gruzovi

Antarctoscyphus gruzovi (Stepanjants, 1979)

(Figure 11)

Sertularella gruzovi Stepanjants, 1979, p. 67, pl. 12, fig. 1, pl. 25, fig. 5.

Antarctoscyphus gruzovi – Peña Cantero et al., 1997, p. 26; 1999, p. 1756–9, figs 6, 7D; Soto Àngel and Peña Cantero, 2015, p. 993, fig. 6c–e.

Material examined

Eltanin: 6/418, stem fragment, c. 9 mm long, and branch fragment, c. 8 mm long.

Diagnosis

Stems polysiphonic, unbranched, up to 65 mm high. Cauline internodes distinctly arranged in zigzag fashion. Cauline apophyses alternately arranged in one plane. Paired branch re-branching at second and fifth internodes, giving rise to branches of second order; succeeding branches at every third internode (branches up to the third order). Branch internodes long and slender; decreasing in length distally. Hydrothecae alternately arranged in two planes making an acute angle; strong tendency to unilateral disposition. Hydrothecae cylindrical, long and roughly straight; adcauline hydrothecal wall free. Hydrothecal aperture cusps of similar development and separated by shallow embayments. Gonothecae long and thin, almost cylindrical.

Ecology

Found with gonothecae in February (Stepanjants 1979).

Bathymetric and geographic distribution

Antarctoscyphus gruzovi was reported at depths from 276 m (Soto Àngel and Peña Cantero 2015) to 414 m (Peña Cantero et al. 1999); present material from 311– 426 m.

Species with a known distribution limited to a small area. It had only been recorded for the Elephant Island area (Stepanjants 1979; Peña Cantero et al. 1999; Soto Àngel and Peña Cantero 2015). Our material was collected off the nearby d’ Urville Island (Antarctic Peninsula).