Harmful parasitic crustaceans infecting wild arripids: A potential threat to southern Australian finfish aquaculture

Parasitic crustaceans are responsible for severe disease outbreaks in finfish aquaculture. We provide the first report of five marine ectoparasitic crustacean species including Argulus diversicolor Byrnes, 1985 (Branchiura: Argulidae), Caligus bonito Wilson, 1905, C. longipedis Bassett-Smith, 1898, C. pelamydis Hewitt, 1963, and C. punctatus Shiino, 1955 (Copepoda: Caligidae) on wild arripid hosts, Arripis georgianus (Valenciennes, 1841), A. trutta (Forster, 1801) and A. truttaceus (Cuvier, 1829) (Perciformes: Arripidae) in southern Australian waters. Caligus pelamydis and C. punctatus are new Australian records. All five crustacean species exhibit low host-specificity and Argulus spp., C. longipedis, C. pelamydis and C. punctatus have been associated with mass mortalities in cultured fishes outside Australia. Given the propensity for arripids to aggregate at sea-cage aquaculture sites, awareness of these five parasitic crustacean species may allow health managers to identify and anticipate potential outbreaks on southern Australian fish farms.