Staurotheca compressa Briggs, 1938

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 : 29

Staurotheca compressa Briggs, 1938

( Fig. 10 A)

Staurotheca compressa — Peña Cantero & Vervoort, 2003: 2673 –2676, fig. 4 (synonymy); Peña Cantero, 2006: 940, fig. 4A; 2008: 459; 2009: 1749; 2013: 131; Peña Cantero & Vervoort, 2009: 87; Soto Àngel & Peña Cantero, 2015: 997, fig. 8b–c.

Material examined. Stn 25, mass of stems, ca. 20 mm in diameter (NIWA 117518); Stn 178, mass of stems, ca. 80 mm high and 70 mm wide, with gonothecae, basibiont of Halecium tangaroa sp. nov. and Hebella plana (NIWA 117519); Stn 197, mass of stems, ca. 100 mm in diameter, with female gonothecae (MNCN 2.03/551).

Remarks. This is a species easily distinguishable by the hydrothecal aperture, which is laterally depressed, forming both an adcauline and an abcauline cusp ( Fig. 10 A).

Ecology and distribution. Reviewed by Peña Cantero & Vervoort (2003) and Peña Cantero (2006). Eurybathic species ( Peña Cantero & Vervoort 2003), collected at depths between 45 ( Briggs 1938) and 1042 m ( Peña Cantero & Vervoort 2003); present material at depths from 110 to 348 m, basibiont for colonies of Hebella plana and Halecium tangaroa sp. nov. and with gonothecae in February.

Circum-Antarctic species ( Stepanjants 1979), recently reported from off Livingston Island (Peña Cantero 2006, 2008), Deception and Trinity islands ( Peña Cantero 2008), Bransfield Island and Bransfield Strait ( Peña Cantero & Vervoort 2009), Low Island ( Peña Cantero & Vervoort 2009; Peña Cantero 2013) and Elephant Island ( Soto Àngel & Peña Cantero 2015), in West Antarctica , and from the Balleny Islands (Peña Cantero 2009), in East Antarctica . See Peña Cantero & Vervoort (2003) for previous records. In the Ross Sea, already known off Scott Coast ( Peña Cantero & Vervoort 2003). Present material off Adare Peninsula and Possession Islands .

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).