Abietinella operculata ( Jäderholm, 1903 ), Jaderholm, 1903

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 : 56

Abietinella operculata ( Jäderholm, 1903)

Abietinella operculata — Marques et al., 2005: 1443 –1455 (synonymy); Peña Cantero & Gili, 2006: 765; Peña Cantero, 2008: 453; 2009: 1747; 2014a: 1716; Peña Cantero & Vervoort, 2009: 84; Soto Àngel & Peña Cantero, 2015: 986 –988, fig. 3a.

Material examined. Stn 7, fragment 13 mm long (NIWA 117607); Stn 8, fragment 5 mm long (NIWA 117608); Stn 14, stem 40 mm high (NIWA 117609); Stn 15, two stems up to 12 mm on Schizotricha nana (MNCN 2.03/ 657); Stn 17, five stems up to 60 mm high on Schizotricha nana and S. turqueti (NIWA 117610); Stn 18, two stems up to 7 mm high on hydroid stem (MNCN 2.03/658); Stn 25, stem 40 mm high (NIWA 117611); Stn 30, fragment 7 mm long (NIWA 117612); Stn 34, three fragments up to 9 mm long (NIWA 117613); Stn 39, colony with four stems up to 30 mm high, and extra stem 60 mm high (MNCN 2.03/659); Stn 51, three stems up to 36 mm high (NIWA 117614); Stn 52, three stems up to 27 mm high on Oswaldella stepanjantsae (NIWA 117615); Stn 53, several stems and fragments up to 80 mm high, and incipient stem on bryozoan (NIWA 117616); Stn 67, four incipient stems up to 22 mm high on Schizotricha turqueti , and stem 22 mm high on bryozoan (MNCN 2.03/660); Stn 96, distal stem fragment 26 mm long (NIWA 117617); Stn 112, several stems up to 30 mm high on old mollusc shell, tube of benthic organism, and Stegella lobata (NIWA 117618); Stn 125, stem 30 mm high (MNCN 2.03/661); Stn 126, fragment 18 mm long (NIWA 117619); Stn 130, three stems up to 13 mm high on Staurotheca densa (NIWA 117620); Stn 139, two incipient stems up to 15 mm high on gravel, and stem fragment 11 mm long (NIWA 117621); Stn 140, two stems up to 30 mm high (MNCN 2.03/662); Stn 143, stem 160 mm high (NIWA 117322); Stn 178, stem 70 mm high (MNCN 2.03/663); Stn 198, stem 31 mm high, and two incipient stems up to 6 mm high on gravel (NIWA 117323); Stn 206, five stems up to 45 mm high (NIWA 117324).

Measurements (in µm). Hydrotheca: length of abcauline wall 600–700, length of adcauline wall 480–560, diameter at aperture 180–240.

Ecology and distribution. Shelf and slope species, found at depths between 63 ( Peña Cantero & García Carrascosa 1993) and 1500 m ( Stepanjants 1979); present material from 110 to 975 m, epilithic on gravel and epibiotic on mollusc shell, bryozoans, tubes of benthic organisms and hydroids ( Stegella lobata , Oswaldella stepanjantsae , Schizotricha nana , S. turqueti and Staurotheca densa ).

Antarctic–Patagonian distribution ( Stepanjants 1979). Recently reported from off Bouvet Island ( Peña Cantero & Gili 2006), Trinity Island ( Peña Cantero 2008), Low Island ( Peña Cantero & Vervoort 2009) , the South Sandwich Islands and Discovery Bank ( Soto Àngel & Peña Cantero 2015), in West Antarctica , and from the Balleny Islands (Peña Cantero 2009) and off Queen Mary Coast ( Peña Cantero 2014a), in East Antarctica . See Peña Cantero et al. (2004) for previous records. In the Ross Sea, already known off Cape Adare ( Marques et al. 2005). Present material collected off Cape Adare, Adare Peninsula, Possession Islands, Moubray Bay and Cape Hallet.