Rhizorhagium antarcticum ( Hickson & Gravely, 1907 )

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 : 9-10

publication ID	https://doi.org/10.11646/zootaxa.4293.1.1
publication LSID	lsid:zoobank.org:pub:6FF96B5C-1F80-47ED-9962-19603DCBF550
DOI	https://doi.org/10.5281/zenodo.4386740
persistent identifier	https://treatment.plazi.org/id/C84B87CA-CC1E-FFBC-E8DD-05120DB3F02D
treatment provided by	Plazi (2017-07-15 08:54:54, last updated 2024-11-24 23:40:41)
scientific name	Rhizorhagium antarcticum ( Hickson & Gravely, 1907 )
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Rhizorhagium antarcticum ( Hickson & Gravely, 1907) View in CoL

( Fig. 2 View FIGURE 2 C)

Perigonimus antarcticus Hickson & Gravely, 1907: 4 View in CoL –6, pl. 1 figs 1–3, pl. 4 fig. 32.

Atractylis antarcticus — Ritchie, 1913: 10, 11.

Gravelya antarctica — Totton, 1930: 139 –140, fig. 1a, b.

Rhizorhagium antarcticum— Peña Cantero et al., 2013: 735–736, figs 2c–d, 3a–b; Peña Cantero, 2015: 377–378, figs 1C, D, 2E, 3F (synonymy).

Material examined. Stn 25, a few polyps, with gonophores, on Schizotricha turqueti Billard, 1906 , and numerous polyps on Staurotheca densa Peña Cantero & Vervoort, 2003 (NIWA 117473); Stn 53, a few stolonal, pedicelated polyps, on Staurotheca densa (MNCN 2.03/527); Stn 130, a few polyps on Staurotheca densa (NIWA 117474); Stn 198, one stolonal colony with four polyps on Schizotricha nana Peña Cantero, Svoboda & Vervoort, 1996 (MNCN 2.03/528).

Measurements (in µm). Cnidome: microbasic euryteles (seen discharged) [range 7.0–8.0 x 3.5–4.0, mean 7.4±0.3 x 3.8±0.2 (n=10); ratio, range 1.8–2.1, mean 1.9±0.1 (n=10)], desmonemes [range 4.5–5.0 x 3.0].

Ecology and distribution. Recently reviewed by Peña Cantero (2015). Shelf species found at depths from the tidal level ( Hickson & Gravely 1907) to 450 m ( Totton 1930); present material between 110 and 222 m, epibiotic on Schizotricha nana , S. turqueti and Staurotheca densa and with gonophores in February.

Probably Antarctic-Kerguelen distribution (Peña Cantero 2015). In the Ross Sea, already known from McMurdo Sound ( Hickson & Gravely 1907; Ritchie 1913; Totton 1930), Cape Royds ( Ritchie 1913), Cape Adare ( Totton 1930) and Tethys Bay (Peña Cantero et al. 2013). Present material collected off Cape Adare, Adare Peninsula, Possession Islands and Cape Hallett.

References

Billard, A. (1906) Hydroides. In: Joubin, L. (Ed.), Expedition Antarctique Francaise (1903 - 1905) commandee par le Dr Jean Charcot. Masson et C ie, Paris, pp. 1 - 20.

Hickson, S. J. & Gravely, F. H. (1907) Coelenterata. II. Hydroid zoophytes. National Antarctic Expedition (S. S. Discovery) 1901 - 1904, Natural History, 3, 1 - 34, pls. 1 - 4.

Pena Cantero, A. L., Svoboda, A. & Vervoort, W. (1996) Species of Schizotricha Allman, 1883 (Cnidaria, Hydrozoa) from recent antarctic expeditions with R. V. '' Polarstern' ', with the description of a new species. Zoologische Mededelingen, Leiden, 70, 411 - 435.

Pena Cantero, A. L. & Vervoort, W. (2003) Species of Staurotheca Allman, 1888 (Cnidaria: Hydrozoa: Sertulariidae) from US Antarctic expeditions, with the description of three new species. Journal of Natural History, 37, 2653 - 2722. https: // doi. org / 10.1080 / 00222930210155701

Ritchie, J. (1913) The hydroid zoophytes collected by the British Antarctic Expedition of Sir Ernest Shackleton, 1908. Proceedings of the Royal Society of Edinburgh, 33 (1), 9 - 34.

Totton, A. K. (1930) Coelenterata. Part V. Hydroida. Natural History Report, British Antarctic ' Terra Nova' Expedition, 1910, Zoology, 5 (5), 131 - 252, pls 1 - 3.

Figures

FIGURE 2. Bimeria corynopsis Vanhöffen, 1910: A, polyp with swollen tentacle ends; B, nematocysts (microbasic euryteles and desmonemes). Rhizorhagium antarcticum (Hickson & Gravely, 1907): C, discharged microbasic eurytele. Hydractinia sp.: D, polyp. (A, D from Stn 139; B from Stn 140; C from Stn 130). Scale bar: 200 µm (A, D), 10 µm (B – C).