Gyrodactylus anguillae (Monogenea: Gyrodactylidae) from anguillid eels (Anguilla australis and Anguilla reinhardtii) in Australia: a native or an exotic?

A species of Gyrodactylus collected from 2 species of anguillid eels (Anguilla australis Richardson, 1841 and Anguilla reinhardtii Steindachner, 1867) from Australia is identified as Gyrodactylus anguillae Ergens, 1960. The morphology of sclerites of G. anguillae specimens from Australia is in accordance with previous descriptions of specimens collected from A. anguilla (Linnaeus, 1758) from Europe and A. anguilla imported into Japan. Gyrodactylus anguillae was previously thought to be a parasite specific to A. anguilla, an eel that is native to freshwater catchments throughout Europe. Information on eel translocations and host and parasite biology is reviewed and it is hypothesized that G. anguillae is a naturally occurring parasite in Australia and not an introduction.