Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997

ÁLVARO L. PEÑA CANTERO, 2017, Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa, Magnolia Press : 32-33

Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997

( Fig. 10 I)

Staurotheca nonscripta— Peña Cantero & Vervoort, 2003: 2696 –2698, fig. 13 (synonymy); Peña Cantero, 2014a: 1722 –1723, fig. 5e.

Material examined. Stn 26, mass of stems, ca. 100 mm high and 70 mm wide (MNCN 2.03/559); Stn 36, two masses of stems, ca. 40 and 60 mm in diameter, with male gonothecae (NIWA 117531); Stn 53, one stem 55 mm high on pebbles, basibiont of Campanularia sp., Hebella plana , Symplectoscyphus exochus ? Blanco, 1982, and S. weddelli Peña Cantero, Svoboda & Vervoort, 2002 , and a colony fragment 17 mm long (MNCN 2.03/560); Stn 67, four masses up to 60 mm in diameter and several fragments up to 30 mm long, basibiont of Hebella plana , Symplectoscyphus anae Peña Cantero, Svoboda & Vervoort, 2002 , and S. exochus ? (NIWA 117532); Stn 124, colony 30 mm high on Antarctoscyphus grandis (NIWA 117533); Stn 139, six colonies up to 120 mm high and 150 mm wide, basibiont of Bimeria corynopsis , Campanularia hicksoni , Halecium tangaroa sp. nov., Hebella plana , and Lafoea dumosa (MNCN 2.03/609); Stn 140, eight masses of stems up to 80 mm in diameter, with female gonothecae, basibiont of Bimeria corynopsis , Halecium tangaroa sp. nov. and Hebella plana (NIWA 117534); Stn 143, mass of branches 50 mm in diameter, with female gonothecae (NIWA 117535); Stn 144, one fragment 17 mm long, in bad condition (NIWA 117536); Stn 148, two masses, ca. 60 and 70 mm in diameter, with female gonothecae, basibiont of Eudendrium scotti , H. plana , and Symplectoscyphus sp. (MNCN 2.03/610).

Measurements (in µm). Hydrotheca: abcauline wall 500–700, free part of adcauline wall 280–460, adnate part of adcauline wall 420–550, adcauline wall 780–940, diameter at aperture 210–250. Cnidome: larger nematocysts, 20.5– 22 x 4.5–5.

Remarks. Species easily recognizable by the long free portion of the adcauline hydrothecal wall ( Fig. 10 I).

Ecology and distribution. Reviewed by Peña Cantero & Vervoort (2003). Shelf species ( Peña Cantero & Vervoort 2003), found at depths from 15 ( Peña Cantero & Vervoort 2003) to 728 m ( Peña Cantero 2014a); examined material between 197 and 397 m, epilithic on pebbles and epibiotic on Antarctoscyphus grandis , basibiont for colonies of Bimeria corynopsis , Campanularia hicksoni , Campanularia sp., Eudendrium scotti , Halecium tangaroa sp. nov., Hebella plana , Lafoea dumosa , Symplectoscyphus anae , S. exochus ?, S. weddelli , and Symplectoscyphus sp., and with gonothecae in February.

Antarctic –Patagonian distribution (cf. Peña Cantero & Vervoort 2003). Recently reported from off Queen Mary Coast ( Peña Cantero 2014a). See Peña Cantero & Vervoort (2003) for previous records. In the Ross Sea, already known from the central basin and off Scott Coast, Cape Hallett, Coulman Island, Roosevelt Island and Cape Adare ( Peña Cantero & Vervoort 2003). Present material collected off Cape Adare, Possession Islands, Moubray Bay and Cape Hallett

Figures

FIGURE 10. Staurotheca compressa Briggs, 1938: A, hydrotheca. Staurotheca densa Peña Cantero & Vervoort, 2003: B, hydrotheca. Staurotheca dichotoma Allman, 1888: C, hydrotheca. Staurotheca gracilis sp. nov.: D, basal part of a branch with hydrothecal arrangement; E – G, hydrothecae. Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997: I, hydrotheca. (A, from Stn 178; B from Stn 67; C, from Stn 140; D – E, G – H from the holotype; F from the paratype; I from Stn 148). Scale bar: 250 µm (A – C, E – H), 500 µm (D).