crabeater seal Lobodon carcinophaga

The crabeater seal Lobodon carcinophaga is found throughout Antarctica, usually in the pack ice [1,2]. Wandering crabeater seals have been sighted in the Falkland Islands, South Georgia Island, Bouvet Island, Heard Island, New Zealand, Tasmania and southern Australia, South Africa, Uruguay, Brazil, and Argentina [1,2,3]. Photographed here on fast ice near Cape Barne, crabeater seals, particularly young ones, come south into the Ross Sea and McMurdo Sound during summer months [2,4]. The crabeater seal is the most abundant seal in the world, with a population between fifteen and forty million (more than all other seals put together) [1]. The crabeater seal weighs up to 225 kilograms (496 pounds) and their length is up to 260 centimeters (8.5 feet) [1].

The color of the crabeater seal grades from blond on its ventral bottom side to darker brown on their dorsal top side [2]. The crabeater seal has characteristic net-like chocolate-brown markings and fleckings on its shoulders, sides and flanks [1]. When approached, crabeater seals do not roll onto their backs like Weddell seals; they open their mouths, bare their teeth, and snort [1,4].

The leopard seal is an important predator of young crabeater seals [1]. Killer whales have been observed creating waves to swamp an ice floe on which a crabeater seal is hauled out, thus knocking the seal into the water [5].

The crabeater seal has ornate interlocking cheek teeth with four or five cusps, functioning as strainers to separate krill from seawater [1].

The crabeater seal eats mostly Antarctic krill Euphausia superba and trivial amounts of fish, squid, and other invertebrates [1]. The crabeater seal is the major consumer of krill in the Southern Ocean [1].

Crabeater seals have been found dead and alive up the Dry Valleys near McMurdo Sound, where they can wander inland great distances [2,4]. Young crabeater seals disperse and spread out; they may become trapped by the autumn freezing sea ice in McMurdo Sound [4]. Trapped seals then have to escape over the ice surface to open water (if they can find the open water) [4]. Crabeater seals are more agile on land and ice than other Antarctic seals and thus can travel far from the open sea [4]. In addition to the Dry Valleys, dead crabeater seals have been found on the McMurdo Ice Shelf eleven kilometers west of Scott Base, 47 kilometers up the Ferrar Glacier at almost 1,100 meters altitude, and one kilometer inland on Cape Evans on the lower slopes of Mount Erebus [4].

Taxonomic Note: The species is usually improperly spelled with a masculine ending, carcinophagus [3]. The correct gender ending is carcinophaga since it is a noun in apposition and not an adjective, thus retaining its original feminine ending even though it is used with a masculine genus [3].

1: FAO Species Identification Sheets for Fishery Purposes : Southern Ocean (Fishing Areas 48, 58 and 88) (CCAMLR Convention Area) / W Fischer & JC Hureau, eds. Rome : Food and Agriculture Organization of the United Nations, 1985; 2: Handbook of Marine Mammals, Volume 2, Seals. SH Ridgway & RJ Harrison, eds. London: Academic Press, 1981, pp.221-235; 3: Marine Mammals of the World : Systematics and Distribution. DW Rice. Lawrence, Kansas : Society for Marine Mammalogy, 1998; 4: Journal of Mammalogy 52(1):175-180, 1971; 5: Canadian Journal of Zoology 59(6):1185-1189, 1981

Text ©Peter Brueggeman. Photographs ©Peter Brueggeman & M Dale Stokes. Photograph may not be used in any form without the express written permission of Peter Brueggeman & M Dale Stokes.