The Freshwater Fish Epidemics in Queens- 

 land Rivers. 



By Professor T. Harvey Johnston, M.A., D.Sc, F.L.S., 



and 



M. J. Bancroft, B.Sc, formerly Walter and Eliza Hall 

 Fellow in Economic Biology, University, Brisbane. 



{Read before the Royal Society of Queensland, 28th Nov., 1921.) 



At irregular intervals very widespread and deadly ej)!- 

 demics have appeared amongst freshwater fish in Queensland 

 rivers, more esj)ecially those in the western portions of the 

 State. We have endeavoured to ascertain the cause of the 

 mortality but have not as yet succeeded. The outbreaks occur 

 usually in localities that are not readily accessible and moreover 

 generally last for a short time. These facts, together with tardy 

 arrival of information as to the presence of the malady in any 

 particular district, have prevented either of us from being 

 present during an actual outbreak, though on one occasion 

 a visit was paid to a locality just as an epidemic had subsided. 



Since one of us has now left the State and the other has 

 undertaken additional duties, it seems unlikely that either will 

 be able, for some time at least, to give further attention to the 

 matter now under consideration. We have therefore thought 

 it advisable to bring together the information which Ave have 

 collected, so that it may form a basis for some future worker. 



We take this opportunity to express our indebtedness 

 to the following for their kind assistance : — Mr. W. Hamilton, 

 Chief Inspector of Fisheries, Brisbane ; Mr. R. Caldwell (Charle- 

 ville) ; Messrs. M. J. Bergin (Goondiwindi), W. H. Ryan 

 (Charleville), J. McKinley (Goondiwindi), and J. Hogan (Ingle- 

 wood) of the Pohce Department ; Messrs H. A. Longman 

 and J. D. Ogilb}^ Queensland Museum ; Messrs. F. Mills, T. 

 Woulfe, and members of the Longreach Shire Council ; R. 

 Vamey (Brisbane) ; A. V. Stretton (Rankine River) ; J. F. 

 Colbert (Lake Nash) ; W. H. Rudd (Austral Downs) ; the 

 last-mentioned three localities being situated in the Northern 



