GramastacusGramastacus is a genus of freshwater crayfish species from southeast Australia. It has two described species.DiscoveryTwo species of Gramastacus were originally described in 1972 by Edgar Riek from the Grampian region of western Victoria, Australia: Gramastacus insolitus and Gramastacus gracilis. In 1990, G. gracilis was determined to be a junior synonym of G. insolitus. In 2014, a new species Gramastacus lacus from the coastal regions of New South Wales was formally described by McCormack.SpeciesWestern Swamp Crayfish - Gramastacus insolitus Riek, 1972 - a very small non-burrowing crayfish that shares burrows with larger crayfish speciesEastern Swamp Crayfish - Gramastacus lacus McCormack, 2014 - a larger, more robust crayfish species that digs their own burrows