ARTIFICIAL PROPAGATION OF STURGEON. 5 



about six days in a water temperature of 65° F. The fish from which 

 they were secured were taken especially for the work, and their vio- 

 lent struggles when caught frequently resulted in the loss of many 

 of their eggs. Such losses were unavoidable, as it was possible to 

 distinguish a ripe female only when the eggs ran from it after it was 

 taken from the water. 



In 1911 experimental sturgeon propagation was undertaken in 

 Minnesota in the Lake of the Woods region. In advance of the 

 season's run of fish an inclosure large enough to hold 30 adult stur- 

 geon was constructed in Rainy River, and a hatching apparatus of 

 sufficient capacity to accommodate 3,000,000 eggs and fry was set 

 up in a convenient building. During the spring 16 sturgeon were 

 captured in a pound net and transferred to the pen. Though held 

 for several months under apparently favorable conditions, they 

 failed to mature, and in the following October they were released 

 without having produced any eggs. Another trial was made in the 

 following year with the same results. 



From the observations made it was concluded that sturgeon do not 

 spawn until the water has attained a temperature of 60° F. ; that 

 the eggs do not ripen in fish held in confinement; and that unless 

 nearly ripe males are available when the eggs are taken no results 

 can be expected. The spawning season at the various grounds has 

 always been short, seldom exceeding three or four days. It is be- 

 lieved that jars similar to those used in the propagation of white- 

 fish and pike perch are the most suitable form of equipment for the 

 development of sturgeon eggs. 



