Bimeria corynopsis Vanhöffen, 1910

Soto, Joan J. & Peña, Álvaro L., 2019, Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica), Zootaxa 4570 (1), pp. 1-78 : 9

Bimeria corynopsis Vanhöffen, 1910

( Fig. 2 a–c)

Material examined. ANT XV/3: 48-150, stolonal colony up to 1 mm high, with two polyps, on Eudendrium scotti Puce, Cerrano & Bavestrello, 2002 .

Remarks. In spite of being scarce, our material perfectly agrees with the description of the syntypes examined by Peña Cantero (2015), including the slightly-capitate appearance of tentacles ( Fig. 2c ), which has been considered as the diagnostic trait of the species (see Schuchert 2007).

Cnidome consisting in microbasic euryteles [range 7.5– 9 x 5.0–5.5 µm, mean 8.6±0.5 x 5.2±0.3 µm (n=21)] and desmonemes [range 4.5–5.0 x 3.0–3.5 µm, mean 4.7±0.4 x 3.3±0.3 µm (n=16)].

Ecology and distribution. Previously found at depths between 231 (Peña Cantero 2017) and 527 m ( Peña Cantero 2014a); present material at 710– 758 m. Hitherto considered as endemic of East Antarctica ( Peña Cantero 2014a); present finding, the fourth report of the species, and the first for both the Weddell Sea and West Antarctica, points to a circum-Antarctic distribution.

Figures

FIGURE 2. a–c Bimeria corynopsis: a stem showing branching; b stem showing annulation; c detail of polyp and slightly capitate tentacles. d–e Bougainvillidae undetermined: d polyp; e gonophore. f–i Rhizorhagium antarcticum: f colony shape; g extended (left) and contracted (right) polyps; h shape (left) and developing eggs (right) of female gonophores; i male gonophore. j?Sarsia sp.: polyp.