clam species goolwa donax Donax deltoides Lamarck, 1818 Plebidonax deltoides (previously *Donax deltoides*) is a small, edible saltwater clam or marine bivalve mollusc of the family *Donacidae*, endemic to Australia. It is most widely known as the pipi in the eastern states of its native Australia, and as the Goolwa cockle or Coorong cockle in South Australia. donax deltoides plebidonax deltoides requires discussion