Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica) Author Soto, Joan J. Author Peña, Álvaro L. text Zootaxa 2019 2019-03-22 4570 1 1 78 journal article 27992 10.11646/zootaxa.4570.1.1 66601a1e-ba16-41b2-b182-0fd80e75ccba 1175-5326 2608527 EF369E98-EBD9-4647-B081-65AD1794A27C Hydrodendron arboreum ( Allman, 1888 ) ( Fig. 14 h–j) Material examined. ANT XV/3 : 48-36 , one colony, up to 80 mm high; ANT XVII/3 : 111-5 , one colony, c. 40 mm high; 111-6 , several stems, c. 140 mm high, on stone, with gonothecae; 111-7 , several stems, up to 120 mm high, and few stems, up to 6 mm high, on O. terranovae ; 111-9 , several stems, up to 110 mm high, with gonothecae; 111- 18 , one colony, c. 135 mm high, with gonothecae; 111-19 , one colony, c. 20 mm high; ANT XXI/2 : PS65/39 , a few stems, up to 33 mm high; PS65/278 , one colony, c. 50 mm high; PS65/279 , few stems, up to 35 mm high, on sponge; PS65/280 , one colony, c. 20 mm high; PS65/281 , some stems c. 80 mm high. Ecology and distribution. Species collected between 18 ( Hickson & Gravely 1907, as Halecium arboreum ) and 1370 m depth ( Peña Cantero & Ramil 2006 ); present material at 62– 175 m . Pan-Antarctic species widely distributed in Antarctic and sub-Antarctic waters ( Peña Cantero & Ramil 2006 ). Documented in the Weddell Sea by means of remote operate vehicle ( Dimmler et al. 2001 ), present contribution constitutes the first verifiable record from this Antarctic region.