pleurogoniid isopod Austrosignum grande

Austrosignum grande is found in Antarctica, South Shetland Islands, South Georgia Island, and southern Chile at depths from 0 to 385 meters [1,2,3,6,8].

In this photo, the female is above the male. A. grande is a dominant species in the McMurdo jetty soft-bottom macrofaunal community [7]. A. grande is found on exposed polychaete tubes or plowing through surface sediments [7]. A study examined the gut contents of A. grande and found diatoms and amorphous organic material [7]. Its predators include the fish Trematomus bernacchii and Trematomus hansoni [7].

Pleurogoniid isopods have most of their species in polar or boreal waters with their highest diversity in Antarctica [5]. Deep sea and northern pleurogoniid isopods are derived from genera occurring in Antarctica [5]. This Antarctic center of diversity for pleurogoniid isopods may be due to a narrow range of adaptability to temperature changes [5].

Taxonomic Note: A. glaciale was synonymized with A. grande [1]. The characters of species assigned to the genera Austrosignum and Paramunna are confusing; there may be only one genus or the Antarctic species need redescription [4,5].

1: Fauna i Raspredelenie Rakoobraznykh Notalnykh i Antarkticheskikh Vod (Fauna and Distribution of Crustacea from Notal and Antarctic Waters). AI Kafanov, ed. Vladivostok: Akademiya Nauk SSSR, DVNTS, 1982. pp.73-105; 2: Tethys 5(4):561-600, 1974 (A. glaciale); 3: Systematics and Biology of Bathyal and Abyssal Isopoda Asellota. T Wolff. Galathea Report, Volume 6. Scientific Results of the Danish Deep-Sea Expedition Round the World 1950-52. Copenhagen: Danish Science Press, 1962. p. 255 (A. grande ) and p. 256 (A. glaciale); 4: Journal of Natural History 14(2):215-236, 1980; 5: Gunneria 35:1-128, 1980 ; 6: The Zoogeography, Ecology, and Systematics of the Chilean Marine Isopods. RJ Menzies. Lunds Universitets Arsskrift. Ny Foljd, Avd. 2. Bd 57. Nr 11. Kungliga Fysiografiska Sallskapet Handlingar. Ny Foljd, Bd 72, Nr 11. Reports of the Lund University Chile Expedition 1948-49. Number 42. Lund: CWK Gleerup, 1962; 7: Ophelia 24(3):155-175, 1985 ; 8: Polar Biology 28(1):1-14, 2004

Text ©Peter Brueggeman. Photograph © Canadian Museum of Nature (Kathleen Conlan). Photograph may not be used in any form without the express written permission of Canadian Museum of Nature (Kathleen Conlan).