Studies continued on the success of nesting, hatching and on survival and 

 growth of bass fingerlings. These studies are progressing well towards an under- 

 standing of the mechanism which produces strong bass year classes in particularly 

 warm summers. 



The speckled trout research unit was re-established in the fall of 1960 

 and the remainder of the year was spent in an assessment of the needs of management 

 and of the information available in the literature, A realistic research program 

 for this species has been developed and will be initiated in the spring of 1961. 



Selective Breeding (Splake) 



Some of the experimental planting work concerning splake was reported in 

 previous pages under Lake Huron. Other studies of introduced populations were made 

 in Algonquin Park where the most spectacular observation occurred in Jack Lake, 

 where splake spawned successfully in the fall of 1959 and the young swam away from 

 the beds in the spring of 1960. 



In the mass selection work at the Maple Laboratory, second generation 

 hybrids and speckled trout back-crosses are being reduced, by two selection stages, 

 to the 10 per cent that are best able to retain swim-bladder gas. Four year 

 classes of speckled trout back crosses, and three year classes of F2 hybrids, are 

 now on hand. Selections are not yet possible on the latest year class, and are not 

 yet complete on some of the earlier year classes. The project is being seriously 

 limited through lack of working space and facilities, which has the effect of cur- 

 tailing progress at the very time when success is most urgently needed. Splake are 

 scheduled for introduction to Great Lakes waters as an alternative to lake trout if 

 sea lamprey control is unsuccessful. 



In that phase of the project in which branded individuals are mated and 



their progeny reared in individual family groups, there have been some significant 



results. Some of these matings have produced a higher proportion of progeny with 



the ability to retain gas than other matings. Similarly some matings produced 



progeny with a much higher viability than others. 



» 



14 



