Antarctoscyphus spiralis ( Hickson and Gravely, 1907 )

Peña Cantero, Álvaro L. & Marzal, Marina Fresneda, 2018, Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica), Zootaxa 4441 (1), pp. 121-136 : 127

Antarctoscyphus spiralis ( Hickson and Gravely, 1907)

( Fig. 3D )

Symplectoscyphus spiralis — Briggs, 1938: 34 –35.

Antarctoscyphus spiralis —Peña Cantero et al., 2017: 31–34, fig. 13 (synonymy).

Material examined. 29EV59, a stem fragment 70 mm long (IK–2009–0335); 63EV314, a colony fragment 70 mm long, with gonothecae (IK–2012–10434).

Remarks. This is a well-known species, easily recognizable by the presence of three internal cusps situated at the embayments between the cusps of the hydrothecal aperture ( Fig. 3D ). See Peña Cantero et al. (2017) for a recent diagnosis.

Ecology and distribution. Our material was collected from depths between 423 and 480 m, and with gonothecae in January. Previously reported by Briggs (1938), at depths between 99 and 720 m, from Commonwealth Bay. Circum-Antarctic distribution ( Stepanjants 1979).

Figures

FIGURE 3. Staurotheca antarctica Hartlaub, 1904: A, hydrothecae. Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997: B, hydrotheca. Staurotheca pachyclada (Jäderholm, 1904): C, hydrotheca. Antarctoscyphus spiralis (Hickson & Gravely, 1907): D, internode with hydrotheca showing intrathecal cusps (arrow). Symplectoscyphus glacialis (Jäderholm, 1904): E, internode with hydrotheca. Halecium interpolatum Ritchie, 1907: F, incipient stem with distal hydrotheca (arrow pointing to characteristic long and straight basal part of internode). Abietinella operculata (Jäderholm, 1903): G, hydrotheca (arrow pointing to disc-shaped operculum) and nematotheca (arrow). Schizotricha nana Peña Cantero, Svoboda & Vervoort, 1996: H, unforked hydrocladial internodes showing hydrothecae and nematothecae. Oswaldella erratum Peña Cantero & Vervoort, 1997: I, hydrocladial internode showing hydrotheca and mesial inferior nematotheca (arrow). Scale bars: 200 µm.