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, Zootaxa 4293 (1), pp. 1-65 : 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).