Observations on new Myxobolus species and Kudoa species infecting the nervous system of Australian fishes

Myxobolus galaxii sp. nov. from the spinal cord of Galaxias olidus in northeast Victoria induced little pathologicaf change even when present in lare numbers. Myxobolus gadopsii sp. nov. was found in the meninx and other connective tissues of Gadopsis marmoratus popufations within all three mainland Victorian enotypes as well as in G. bispinosus. Myxobolus gadopsii also appeared to be harmless to its hosts. Kudoa sp. from the brain of Lates calcarifer in north Queensland was associated with abnormal swimming behaviour in juveniles but not in adults. A further Kudoa species, probably K. nova or K. clupeidae, was examined in Thunnus maccoyii from Western Australia, where it was found that most, if not all, of the infections developed in peripheral nerves.