Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997a

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 : 126

Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997a

( Fig. 3B )

Staurotheca nonscripta —Peña Cantero & Vervoort, 2003: 2696 –2698, fig. 13 (synonymy).

Material examined. 48EV194, fragments up to 22 mm long, with male and female gonothecae (IK–2012–10435), and a mass of stems 70 mm in diameter, with male and female gonothecae (IK–2009–0300).

Description. Compact monosiphonic colonies consisting of a mass of stems and branches irregularly branched in several planes, up to 70 mm in diameter. With anastomoses. Hydrothecae arranged in decussate pairs, forming four longitudinal rows, immersed into the branches for approXimately one-quarter of their volume and strongly curving outwards. Adcauline hydrothecal wall with a considerable free portion ( Fig. 3B ), adnate to internode for half or slightly more of its length. Free part of adcauline wall straight or slightly conveX; abcauline wall concave. Hydrothecal aperture circular; rim even and usually with numerous renovations. Gonothecae inserting at hydrothecal base. Female gonotheca urn-shaped; basal part ovoid, distally contracted into a short neck with distal aperture. Male gonotheca fusiform, with cone-shaped neck provided with a small, circular aperture.

Ecology and distribution. Our material was collected at depths between 325 and 409 m, basibiont of Bimeria corynopsis and Campanularia hicksoni and with gonothecae in December. Antarctic-Patagonian 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.