THE METHODS, LIMITATIONS, AND RESULTS OF WHITEFISH- CULTURE 



IN LAKE ERIE. 



BY J. J. STRANAHAN, 



Superintendent of United States Fish Commission Station, Pul-in Bay, Ohio. 



Iii a paper of this character it will not be possible to go into details as to the 

 methods pursued in whitefish-culture, nor do I deem it necessary, since the subject 

 has been so often and so ably treated; but I will rather confine myself to what I 

 conceive to be some comparatively new and interesting features of the work. 



To summarize, it is only necessary to say that the mode pursued at the Put-in 

 Bay station of the United States Fish Commission is the same as that generally 

 followed, dry impregnation being the starting point that is, the eggs and milt are 

 brought into contact as they come from the fish and well mixed, after which water is 

 added, the mass gently stirred and allowed to stand about 2 minutes, when the eggs 

 are washed and placed in wooden kegs holding 15 gallons each. 



In this connection it will be proper to state that a series of experiments made at 

 Put-in Bay station the past season demonstrates that in water the milt loses much of 

 its vitality at the close of 1 minute. In fact, at the close of minute it has done its 

 best work. In one test only 49 per cent of the eggs were impregnated by milt which 

 had stood in water 1J minutes, and in another 47 per cent where it had been 1 

 minutes in the water j while eggs from the same lot showed 98 per cent and 97 per cent 

 impregnation, respectively, where milt was used from the same lot which had stood 

 but \ minute in the water. It is therefore obvious that reliance should not be placed in 

 milt which has stood over 1 minute in water, and it follows that eggs should be washed 

 at the close of 2 minutes, as the longer they stand in the milt after impregnation has 

 taken place the worse for the eggs, as shown by Professor Reighard and other writers. 



After being brought to the station, some 2 to 10 hours after taking, the eggs are 

 kept in the kegs in running water and carefully stirred once an hour until the next 

 forenoon, it being our belief that while "harding" that is, while the investing 

 membranes are filling with water they should not be submitted to even the gentle 

 motion which they undergo in the jars. 



It is evident to all observant fish-culturists that the eggs must be treated in the 

 most gentle manner possible from the time they are taken up to the period when they 

 are sufficiently cushioned by water to protect them from injury. 



As is well known, many whitefish and lake- trout eggs are annually lost through 

 lack of males at certain times, especially near the close of the season, when large 

 numbers of ripe females are taken from the nets with very few or possibly no males. 

 With this fact in view, experiments were made at Put-in Bay the past season to 

 demonstrate practically how long the milt and eggs can be held separately and still 



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