Two new species of<i>Euastacus</i>(Decapoda: Parastacidae) from the Gondwana Rainforests of central eastern Australia

Abstract

Two new species of the crayfish genus Euastacus are described from the Gondwana Rainforests on the Queensland - New South Wales border region of Australia, Euastacus binzayedi sp. n. and Euastacus angustus sp. n. These two small, poorly spinose species are broadly similar in appearance and colouration to Euastacus dalagarbe Coughran, from the same region. Both species can be readily distinguished from E. dalagarbe; Euastacus binzayedi sp. n. by the numerous bumps and protrusions on the dorsal and ventral surfaces of its chelae, and Euastacus angustus sp. n. by its unusual, laterally compressed body shape, and the large ventromesial carpal spine. Cytochrome oxidase I divergence estimates from the most closely related species were high for both Euastacus binzayedi sp. n. (4.8%), and Euastacus angustus sp. n. (8.7%). Morphologically, both of these new species belong in a clearly defined, poorly spinose grouping, and both appear to be exceptionally rare, each known from a single locality.