Cryosignum nordenstami Just & Wilson 2021, sp. nov.

Cryosignum nordenstami sp. nov. (Fig. 8) Austrosignum glaciale Hodgson, 1910.— Nordenstam, 1933: 241, fig. 66. ‘ Cryosignum’ undescribed species.— Just & Wilson, 2007: 14. Type fixation. Holotype, ♀, SMNH 79450.—Here designated. Type locality. South Georgia, north of Grytviken. Etymology. The sp...

Full description

Bibliographic Details
Main Authors: Just, Jean, Wilson, George D. F.
Format: Other/Unknown Material
Language:unknown
Published: 2021
Subjects:
Online Access:https://zenodo.org/record/4697826
https://doi.org/10.5281/zenodo.4697826
Description
Summary:Cryosignum nordenstami sp. nov. (Fig. 8) Austrosignum glaciale Hodgson, 1910.— Nordenstam, 1933: 241, fig. 66. ‘ Cryosignum’ undescribed species.— Just & Wilson, 2007: 14. Type fixation. Holotype, ♀, SMNH 79450.—Here designated. Type locality. South Georgia, north of Grytviken. Etymology. The species is named for Dr Åke Nordenstam, who reported these specimens from South Georgia. Material examined. Holotype. ♀ (pereiopods I missing), 1.5 mm. South Georgia, north of Grytviken, 54°22’S, 36°28’W, 12–15 m, sand and algae, Swedish Antarctic Expedition 1901–1903, stn 28, 24 May 1902, SMNH 79540. Paratype. Same data as holotype. SMNH 79541, (♂ 1.5 mm, pereiopods I and pleopod I missing). Description. Body width 0.43 length in female, 0.40 in male, widest at pereionite 3 in both. Head length 0.40 width (♀), length posterior to eyestalks 1.4 anterior length. Frontal margin nearly straight with rounded angular lateral margins adjacent to antennae. Eyestalks length 2.4 width, apex rounded, long axis angling forward at 35–40°. Pereionite 1 female sagittal length 1.4 pereionites midline length, 1.8 in male; pereionite 1–7 lateral margin rounded. Coxal plates 1–7 simple, squarish (except 1 in male bluntly pointed), visible in dorsal view. Pleon length 1.9 width in female, 1.7 in male. Pleonite 1 width subequal to distance between uropods in both sexes, length 0.5 width in female, 0.6 in male. Pleotelson slender, laterally convex, smooth, with small inflection between lateral and proximal margins; posterior margin forming 60° angle, with slight concavity level with uropods in female, 80° angle without concavity in male, apex in both pointed. Antennula with 6 articles, articles 1–2 combined extending beyond eyestalk apex; article 1 about half length of 2, inflated; articles 3, 5 and 6 of subequal length, longer article 4. Antenna article 3 tubular, width 0.33 length, article 5 distinctly longer than article 4; flagellum proximal article distinctly longer than more distal articles. Operculum ovoid, width 0.7 length, without ...