Published March 22, 2019 | Version v1
Taxonomic treatment Open

Corymorpha microrhiza

Description

Corymorpha microrhiza (Hickson & Gravely, 1907)

(Fig. 5 i–l)

Material examined. ANT XVII/3: 111-9, few polyps, up to 80 mm high, on gravel, with mature gonophores; ANT XXI/2: PS65/253, few polyps, up to 80 mm high, with developing gonophores; PS65/280, few polyps, up to 140 mm high, with mature gonophores.

Remarks. Similarly to Z. parvula, Corymorpha microrhiza was first described as Lampra microrhiza (Hickson & Gravely, 1907), and then allocated within Corymorpha by Stepanjants (1972), re-allocated within Lampra by Stepanjants & Svoboda (1999), and in Monocaulus by Svoboda & Stepanjants (2001). However, the species is now considered to belong to Corymorpha (Vervoort 2009).

Svoboda & Stepanjants (2001) provided a detailed description of the syntypes and additional material from the Weddell Sea. Specimens examined here concur in every aspect, but for the presence of branched blastostyles, although exclusively observed in large and mature specimens (Fig. 5j). The original description by Hickson & Gravely (1907) refers branched blastostyles, but Svoboda & Stepanjants (2001) were not able to determine this character in the type material. This discrepancy could be attributed either to putative sexual dimorphism or to the fact that the material examined by these authors was not completely developed. Cnidome information was not given in previous descriptions. Therefore, until the analysis of the cnidome in the type series, none of the records can be ascribed with confidence to C. microrhiza.

Cnidome consisting of stenoteles [range 11.0–13.0 x 8.0–11.0 µm, mean 11.9±0.8 x 9.9±0.9 µm (n=15)], rounded haplonemes [range 16.0–17.5 x 13.5–14.5 µm, mean 17.0±0.5 x 14.1±0.3 µm (n=15)] and desmonemes [range 7.0–7.5 x 6.5–7.5 µm, mean 7.3±0.3 x 7.1±0.3 µm (n=15)].

Ecology and distribution. Species previously known from 237 to 629 m (Svoboda & Stepanjants 2001, as Monocaulus microrhiza); present material collected from 62 to 309 m. Little-recorded species, only known from the Ross Sea (Hickson & Gravely 1907, as Lampra microrhiza) and the Weddell Sea (Svoboda & Stepanjants 2001). Probably circum-Antarctic distribution (Svoboda & Stepanjants 2001). Present contribution represents the third record of the species.

Notes

Published as part of Soto, Joan J. & Peña, Álvaro L., 2019, Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica), pp. 1-78 in Zootaxa 4570 (1) on pages 18-19, DOI: 10.11646/zootaxa.4570.1.1, http://zenodo.org/record/2608527

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Linked records

Additional details

Biodiversity

Family
Corymorphidae
Genus
Corymorpha
Kingdom
Animalia
Order
Anthoathecata
Phylum
Cnidaria
Scientific name authorship
Hickson & Gravely
Species
microrhiza
Taxon rank
species
Taxonomic concept label
Corymorpha microrhiza (Hickson, 1907) sec. Soto & Peña, 2019

References

  • Hickson, S. J. & Gravely, F. H. (1907) Coelenterata. II. Hydroid zoophytes. National Antarctic Expedition (S. S. Discovery) 1901 - 1904, Natural History, 3, 1 - 34.
  • Stepanjants, S. D. (1972) Hydroidea of the coastal waters of the Davis Sea (collected by the XIth Soviet Antarctic Expedition of 1965 - 1966). In: Biological results of the Soviet Antarctic Expedition, 5. Issledovaniya Fauny Morei, 11, 56 - 79. [in Russian]
  • Stepanjants, S. D. & Svoboda, A. (1999) Genera and species of Antarctic Corymorphinae with the discussion concerning structure of this subfamily. Proceedings of the Zoological Institute Russian Academy of Sciences, 281, 47 - 54.
  • Svoboda, A. & Stepanjants, S. D. (2001) Redescription of two Antarctic Corymorphidae species and the reestablishment of the genus Monocaulus (Cnidaria: Hydrozoa). Pubblicazione Stazione Zoologica Napoli, Marine Ecology, 22, 53 - 70. https: // doi. org / 10.1046 / j. 1439 - 0485.2001.00742. x
  • Vervoort, W. (2009) Corymorpha tomoensis Ikeda, 1910 (Cnidaria, Hydrozoa); first record of a corymorphid hydropolyp from Indonesian waters and a review of the species of Corymorpha M. Sars, 1835. Zoologische Mededelingen, 83, 759 - 776.