Westralunio carteri is a species of freshwater mussel in the family Hyriidae. It is endemic to Western Australia. It is known by the common name Carter's freshwater mussel. This is the only species of the genus Westralunio found in Australia.
Westralunio carteri generally has separate sexes (males and females), but hermaphrodites occur occasionally. Gametes (sperm in males or eggs in females) develop in the gonads and, with the onset of spawning, eggs migrate from the female gonads (ovaries) into specialised areas of the gills known as 'marsupia'. At this stage, females are 'gravid'. Fertilised eggs of Westralunio carteri (and other species of Hyriidae) are brooded to become embryos, which develop into larvae, known as 'glochidia'.
