AFFECTED SALMON, MIRAMICHI HATCHERY I53 



SESSIONAL PAPER No. 38a 



a disastrous effect upon the fish as to produce sluggishness and death in the short 

 period of time mentioned by the officer of the hatchery and by Dr. Huntsman, and it 

 therefore seemed important to make a thorough examination of the diseased fish to 

 see if there were other factors producing disease, and to ascertain if the fungtrs 

 Saprolegnia, was a primary or a secondary invader. Unfortunately such investigation 

 was hami)ered by the fact that no live salmon were available for inoculation, and the 

 cnly means of ascertaining the pathogenicity of the organisms isolated was to attempt 

 lo infect the common gold fish. 



During the course of this examination I obtained a publication of the Fishery 

 Board of Scotland entitled ''The Life-history of Salmon in Fresh water, Glasgow, 

 1898," containing a paper by J. Hume Patterson, Assistant Bacteriologist of the 

 Corporation of Glasgow, on "The Cause of Salmon Diseases", and I am indebted to 

 this pai^er for the methods which were subsequently used for the inoculation of the 

 live gold fish. 



Before the gold fish could be inoculated it was necessary to work out in some 

 detail the various organisms which v/ere isolated from the salmon. The principal 

 biological and cultural characteristics of those were as follows : — 



A. 1. 



A medium sized bacillus with rounded ends, occasionally bent, which occurs singly 

 and sometimes in short chains. Actively motile, stains well with methylene blue, 

 and is gram negative. 



GelaHne Plates: — 



2J^ hours, colonies just visible to the naked eye. 



JtS hours, colonies 2 mm. in diameter, round, with a liquefying centre saucer- 

 shaped. Centre of the colony dense with a mass of deposited bacteria. 



With § objective edges of the colony seemed slightly fimbriate, and the mass 

 within the centre might be seen moving. 



3 days, colonies had grown to between 5 and 9 mm. in diameter, but with 

 similar appearance to that at 48 hours. 



.4 days, geletine completely liquefied. 



Gelatine Stick: — 



Growth is best at the top. Line of puncture filiform. 



SJf hov/rs. Liquefaction begins, extending to the sides of tube and about 2 

 mm. in depth, 



JfS hours, growth uniform, line of pimcture a cloudy area 10 mm. in diameter 

 with small outgrowths into gelatine forming a cloudy cylinder. At the surface 

 liquefaction is stratiform to a depth of 4 mm. 



S days, the growth has increased, stratified liquefaction extended to a depth 

 of 7 mm. and the cloudy area looks like a saccate cylinder, 



8 days, liquefaction to a depth of 8 mm. 



10 days, there is a distinct dark stratum underneath the liquefied area. 



13 days, very slight increase. 



Beef Peptone Agar, J^S hours: — ' 



Colonies 1-2 mm. diameter, round, raised, entire edge, glistening white 

 appearance. "With the 3 objective the edges were entire, colonies dense, and 

 grandular with a narrow clear margin. 



S days, colonies 2-5 mm. diameter, round, more massive and dense, convex, 

 whiteish to light brown in centre. 

 38a— 11 



