Halecium pseudoincertus Peña Cantero, 2014

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 : 51-52

Halecium pseudoincertus Peña Cantero, 2014

( Fig. 16 C)

Halecium pseudoincertus Peña Cantero, 2014b: 271 –273, figs 10B, 12.

Material examined. Stn 8, stem 90 mm high (MNCN 2.03/650); Stn 15, stem 65 mm high (NIWA 117597); Stn 17, eight stems up to 180 mm high on pebbles (NIWA 117598); Stn 102, stem 90 mm high, with hydrorhizal stolons attached to gravel (MNCN 2.03/651); Stn 206, stem 90 mm high (NIWA 117599).

Measurements (in µm). Cnidome: isorhizas [range 9.5–11.0 x 3.0–3.5, mean 10.3±0.5 x 3.3±0.2 (n=11); ratio, range 2.9–3.7, mean 3.1±0.3 (n=11)]; larger microbasic euryteles [range 13.0–14.0 x 6.0, mean 13.4±0.4 x 6.0±0.0 (n=4); ratio, range 2.2–2.3, mean 2.2±0.1 (n=4)].

Remarks. See Peña Cantero (2014b) for the description of the species, as well as for a wide discussion about its similarities with the morphologically close H. incertus Naumov & Stepanjants, 1962 .

Ecology and distribution. Shelf and slope species collected at depths from 96 (Peña Cantero 2009) to 1019 m ( Peña Cantero 2008); present material between 420 to 975 m, epilithic on pebbles and gravel. Circum-Antarctic distribution ( Peña Cantero 2014b). Present material is the first record from the Ross Sea , collected off Cape Adare and Possession Islands .

Figures

FIGURE 16. Halecium exaggeratum Peña Cantero, Boero & Piraino, 2013: A, cauline internode with hydrophore and primary hydrotheca; B, gonotheca. Halecium pseudoincertus Peña Cantero, 2014: C, internode with primary and secondary hydrotheca. Halecium secundum Jäderholm, 1904: D, internodes with primary hydrothecae and branch origin with ahydrothecate intermediate internode. Scale bar: 100 µm (A), 200 µm (B – D).