130 REPORT OF COMMISSIONER OF FISH AND FISHERIES.'' 



better able to take care of tliemselves than if deposited at an earlier 

 stage. In the spring of 1896, about 1,000 whitefisli fry were held in one 

 of the station troughs until late in April, with no other food than the 

 entomostraca and other minute life which came into the troughs with 

 the water pumped from the lake. They grew considerably and were 

 remarkably active. Cannibalism was of frequent though not of general 

 occurrence; toward the close of the period through which the fry were 

 held, numbers could be seen which had seized others by the tails and 

 swallowed as much of the bodies as ])ossible, which was, of course, but 

 little. In every case one of the larger had attacked one of the smaller, 

 the victim being dead and his destroyer swimming about actively with 

 the body of the dead fry trailing along his side. If these fry had been 

 regularly supplied with food, it is not probable that cannibalism would 

 have occurred. 



BEARING IN PONDS. 



There have been few attempts to raise whitefish in ponds on a large 

 scale, but experiments lead to the belief that under favorable condi- 

 tions whitefish can be raised in artificial ponds to some extent. Of 

 course an abundance of good cold water, suitable ground for the con- 

 struction of deep ponds, and convenience to railroad communication 

 would be essential to success. 



A successful experiment in this direction was began at Northville in 

 1882. The fish were treated as young trout are, being fed wholly on 

 liver. Three-year-old whitefish, artificially reared, yielded a large num- 

 ber of eggs, a fair percentage of which were fertilized. Fish weighing 

 from 3 to 4^ pounds, that had never been fed on anything but liver, 

 were plump and healthy. Similar successful experiments have been 

 made in Europe with one of the native whitefishes ( Coregonus lavaretus). 



The most noteworthy experiments in the rearing of whitefish in ponds 

 have been conducted by private enterprise at Warren, Indiana. The 

 following account of the work will be of interest: 



In 1890, 50,000 whitefish fry, obtained from the Sandusky station of the United 

 States Fish Commission, were placed in a pond 20 by 40 feet, having a maximum 

 depth of 5 feet. In November of the same year 864 whitefish, averaging 7^ or 8 inches 

 in length, were taken from the pond. This result was not considered satisfactory, 

 although the conditions were not favorable, as there was no natural food in the pond 

 and no artificial food was regularly supplied, the fish feeding on various kinds of 

 food thrown into the pond from time to time. The fish kept near the bottom, and 

 were never seen from the time of planting to the time the pond was drawn. 



In 1891, half a million eggs obtained at Toledo were hatched with a loss of about 

 30 i")er cent, and the resulting fry, together with a small number procured from Put-in 

 Bay station, were planted in a pond containing the small whitefish previously men- 

 tioned. This pond was 65 by 65 feet and 12 feet deep. It is supposed that practi- 

 cally all the fry were devoured by the larger fish. Prior to the time of planting the 

 young whitefish the older ones were very inactive and seldom seen, but as soon as 

 the plant was made they became very- active, and for a period of two weeks, about 

 sunset, they could be seen leaping and darting up out of the water after the fashion 

 of black bass chasing minnows. 



