Staurotheca antarctica Hartlaub 1904

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 : 125

Staurotheca antarctica Hartlaub 1904

( Fig. 3A )

? Staurotheca antarctica — Briggs, 1938: 26.

Staurotheca antarctica— Peña Cantero & Vervoort, 2003: 2670 –2673, fig. 3 (synonymy).

Material examined. 29EV59, a colony 40 mm in diameter, with female gonothecae (IK–2009–0333).

Description. Compact colony 40 mm in diameter, consisting of a mass of stems and branches. Branching frequent and irregular. Branches numerous and provided with anastomoses. Hydrothecae arranged in decussate pairs, forming four longitudinal rows. Hydrotheca ( Fig. 3A ) small, little immersed into branch. Adcauline hydrothecal wall adnate for about half its length, free adcauline wall curved outwards. Hydrothecal aperture circular; rim with renovations. Female gonothecae on bifid and digitiform process arising from hydrothecal base. Gonotheca globular, ornamented with digitiform projections.

Remarks. The record by Briggs (1938) was considered doubtful by Peña Cantero et al. (1997) because he gave neither description nor measurements, being unable to confirm the identification. It would be necessary to reeXamine Briggs’s material to clarify its systematic position.

Ecology and distribution. Present material was collected at depths between 452 and 480 m, and with gonothecae in December. Briggs (1938) reported the species at depths between 283 and 720 m from Commonwealth Bay. Circum-Antarctic distribution (Peña Cantero & Vervoort 2003).

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.