Sarsia, Lesson, 1843

Soto, Joan J. & Peña, Álvaro L., 2019, Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica), Zootaxa 4570 (1), pp. 1-78 : 19

? Sarsia sp.

( Fig. 2j )

Material examined. ANT XV/3: 48-210, a single polyp, c. 3 mm high; ANT XXI/2: PS65/248, a single polyp, c. 2 mm high, on H. incertus .

Remarks. Aside from Sarsia medelae Gili, López-González & Bouillon, 2006 , a non-parasitic mesobiont inhabiting calcaxonian gorgonians in the Weddell Sea ( Gili et al. 2006), very few reports of the family Corynidae exist for Antarctic waters, most of which could not be assigned to species level with enough solid grounds. Hickson & Gravely (1907) mentioned an undeterminable immature Corynidae from McMurdo Sound (Ross Sea). Later, Stepanjants (1979) reported Sarsia tubulosa (M. Sars, 1835) (as Coryne tubulosa ) from the Davis Sea, although her Antarctic material was infertile. Recently, Peña Cantero et al. (2013) described the early formation of tetraradial canals on reared polyps under laboratory conditions, which let them to assign their material to genus Sarsia with confidence, although no species could be attributed. These authors pointed out that their material might be conspecific with those previous records mentioned above. Material examined here might be also conspecific, but the absence of gonophores precludes a proper assignment even at genus level. Further research is needed regarding the corynids from the Southern Ocean.

Ecology and distribution. Similar specimens were found at depths between three ( Stepanjants 1979, as Coryne tubulosa ) and 40 m (Peña Cantero et al. 2013, as Sarsia sp.); present material collected from 67– 287 m. All the previous records of Sarsia sp. originate from East Antarctica (see Peña Cantero et al. 2013). Present finding constitutes the first evidence of this undetermined corynid from West Antarctica and the Weddell Sea.

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.