The antennular setation and sternal morphology of parastacid crayfishes, with a comparison across Astacidea (Decapoda)

Abstract The crustacean infraorder Astacidea is represented by two freshwater (Astacoidea and Parastacoidea) and two marine superfamilies (Enoplometopoidea and Nephropoidea). The antennule setation and sternal morphology were examined in specimens of 1) Parastacoidea: Cherax destructor, C. quadricarinatus, and C. tenuimanus from the Australian mainland; Astacopsis franklinii from Tasmania; C. gherardii, C. monticola, C. peknyi, and C. snowden from New Guinea; Paranephrops planifrons from New Zealand; Parastacus brasiliensis from Brazil; P. pugnax from Chile; and Astacoides madagascarensis from Madagascar; 2) Astacoidea: Pacifastacus leniusculus from Japan (where it is non-native); Procambarus clarkii and P. virginalis from the aquarium trade; and Cambaroides dauricus, C. schrenckii, C. similis, and C. wladiwostockiensis from Russia; 3) Enoplometopoidea: Enoplometopus chacei from Japan; E. debelius and E. occidentalis from the aquarium trade; and 4) Nephropoidea: Homarus americanus from the USA fish market; Metanephrops neptunus from Taiwan; and Metanephrops japonicus, Nephropsis stewari, and Thaumastocheles japonicus from Japan. Antennular setation and sternal morphology were identified as key taxonomic characters to distinguish between the four Astacid superfamilies (Astacoidea, Parastacoidea, Enoplometopoidea, and Nephropoidea). The two new key characters are described and illustrated in detail.