Amphibolis antarctica is a species of flowering plant in the family Cymodoceaceae.

[2][3] It is referred to by the common names wire weed[4] or sea nymph,[5] and is a seagrass found in coastal waters of southern and western Australia.

[5][6] First published as Ruppia antarctica by Jacques Labillardière in 1807, it has since been moved into numerous genera.

It was finally placed in Amphibolis by Paul Friedrich August Ascherson in 1868, but in 1913 J. M. Black renamed it Pectinella antarctica.

[8] However FloraBase reports an isolated specimen record from east of Port Hedland, over 500 kilometres north-east of Exmouth Gulf.

It can also grow in extremely shallow waters, with its leaves floating on the surface, although this often results in leaf damage and loss.

It has been found growing on a variety of substrates, including sand-covered rock, gravel, sand and clay.