Published December 31, 2007 | Version v1
Taxonomic treatment Open

Cryosignum Just & Wilson, 2007, gen. nov.

Description

Cryosignum gen. nov.

Type species. Paramunna lunata Hale, 1937. — Here designated.

Species included. Cryosignum incisum (Richardson, 1908), comb. nov., C. lunatum (Hale, 1937), comb. nov.

Diagnosis. Body ovate (posteriorly tapering in terminal males). Head front margin evenly convex, not projecting. Terminal males with strongly enlarged and forward pointing lateral parts of pereonite 1. Pereonites dorsally smooth or with low transverse ridges. Pleotelson lateral margins smooth. Eyestalk length at least twice greatest width. Antennula article 1 at most as long as eyestalk. Mandible palp present. Pereopod I carpus oval, with 2 straight robust setae on posterior margin; propodus with 2 robust setae on posterior margin. Pereopod II carpus and propodus posterior margin with a few short robust setae. Uropod endopod straight, apex rounded truncate.

Etymology. The genus name incorporates the Greek ρύος (krios or kryos) meaning cold, alluding to the Antarctic-subantarctic distribution of its component species.

Remarks. Cryosignum differs from Munnogonium and Austrosignum as discussed under Austrosignum (above).

The following specimens reported by various authors as Austrosignum glaciale or A. grande may belong in Cryosignum. Pereopod I of the male of A. glaciale, Monod (1931, dorsal habitus and pereopod I illustrated; specimens not seen by us) has an oval carpus with two robust setae and two robust setae on the propodus. In A. glaciale, Nordenstam (1933; specimens seen by us) the presence of a mandible palp and normal uropods places the specimens in Cryosignum, this is an undescribed species. A. grande, Menzies (1962; specimen seen by us) has an oval pereopod I carpus, a mandible palp and normal uropods. This places the specimen in Cryosignum; it is an undescribed species.

Austrosignum latifrons Menzies, 1962, which we have examined, may belong in Cryosignum, but only because it lacks the definitive features of Austrosignum and has a mandibular palp. Our analysis places this species near but not definitively part of the Cryosignum clade. As a result, we have assigned it to an indefinite generic position (incertae sedis).

Other

Published as part of Just, Jean & Wilson, George D. F., 2007, Revision of Austrosignum Hodgson and Munnogonium George & Strömberg (Paramunnidae) with descriptions of eight new genera and two new species, (Crustacea: Isopoda: Asellota), pp. 1-29 in Zootaxa 1515 on page 14, DOI: 10.5281/zenodo.177291

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Linked records

Additional details

Biodiversity

Family
Paramunnidae
Genus
Cryosignum
Kingdom
Animalia
Order
Isopoda
Phylum
Arthropoda
Taxonomic status
gen. nov.
Taxon rank
genus
Taxonomic concept label
Cryosignum Just & Wilson, 2007

References

  • Hale, H. M. (1937) Isopoda and Tanaidacea. Australasian Antarctic Expedition 1911 - 14. Scientific Reports, Ser. C 2, Zoology and Botany, 2 (2), 1 - 45.
  • Richardson, H. (1908) Isopodes (Deuxieme Memoire). In: Expedition Antarctique Francaise (1903 - 1905) commandee par le Dr Jean Charcot (Eds J. Charcot and L. Joubin). Crustaces, 1 - 8. (Documents scientifiques de Science naturelle, Masson et Cie, Paris.)
  • Nordenstam, A. (1933) Marine Isopoda of the families Serolidae, Idotheidae, Pseudidotheidae, Arcturidae, Parasellidae and Stenetriidae mainly from the South Atlantic. Further Zoological Results of the Swedish Antarctic Expedition 1901 - 1903, 3 (1), 1 - 283.
  • Menzies, R. J. (1962) The zoogeography, ecology, and systematics of the Chilean marine isopods. Reports of the Lund University Chile Expedition 1948 - 49. Lunds Universitets Arsskrift, N. F. Avd. 2, 57 (11), 1 - 162.