Scavenging amphipods from under the Ross Ice Shelf, Antarctica

Amphipods in the genus Orchomene were collected from under the Ross Ice Shelf, Antarctica, 400 km from the shelf edge at a depth of 600 m. A study of 992 individuals of the 3500 captured revealed that the population is dominated by the larger size classes. Two-thirds of the population is composed of males. Ovigerous females will approach and consume bait and females are multiply brooded. The source of nutrition for this population is not definitely known. Identifiable gut contents were bacteria mixed with sediment, pieces of crustacean carapaces, and tissue from apparently cannibalized conspecifics. It is an open question as to whether the population sampled is persistent over time and whether amphipods are common under all of the Ross Ice Shelf.