44 Memoir Sears Foundation for Marine Research 



losses at the consecutive spawnings are visible in the ray sections in the form of 'belts' 

 of 2 to 7 narrower zones (or annuli). These indicate that the interval between spawning 

 periods can vary from 4 to 7 years and more." It is highly desirable to corroborate these 

 findings by observing the frequency of spawning by tagged specimens. 



The principal spawning rivers in Quebec are the St. Francis for Lake St. Peter, 

 and the Batiscan and Chaudiere for the respective sections of the St. Lawrence from 

 Three Rivers to Montmagny. 



The diameter of mature but unfertilized eggs preserved in 4-5% formalin varied 

 between 2.7—3.1 mm. Thus the ripe eggs of A. fulvescens are somewhat larger than 

 those of A. oxyrhynchus. Table 11 gives data on ovaries and eggs from mature females 

 of A. fulvescens from the St. Lawrence River near Quebec. 



Table IL Data on Ovaries and Eggs of A. fulvescens. 



TL 



Locality Date ('^■1^) 



St.Vallier June 5, 1944 136 



St.Vallier May 15, 1950 144 



St.Vallier May 15, 1950 142 



St.Vallier June 17, 1946 145 



St.Vallier May 19, 1946 175 



St.Nicolas May 8, 1949 170 



* Approximate. 



Food. In the St. Lawrence, A. fulvescens subsists on about the same type of food 

 as A. oxyrhynchus (p. 52). In 29 stomachs oi fulvescens we found that larvae of the bur- 

 rowing May fly [Hexagenid) were present in 76 "/o of the samples, amphipods in 73 "/o, 

 gastropod mollusks in 48 "/o, bivalve mollusks in 35%? and fish in 2^"/^. Indeed, 

 A. fulvescens of different sizes are easily taken by hook-and-line, and the best bait is 

 young shad, or, as second choice, banded killifish (Fundulus diaphanus). Harkness^" 

 found that A. fulvescens in Lake Nipigon, Ontario, fed principally on May fly and 

 chironomid larvae and on mollusks. 



Abundance and Commercial Importance. According to official statistics for 1951, the 

 catches of Lake Sturgeon were (in pounds): 9,000 for Saskatchewan, 164,000 for 

 Ontario, 194,000 for Quebec, and 13,000 for the U.S. Great Lakes; total, 380,000 

 pounds, with a combined monetary value of $ 300,000. Late nineteenth-century yields 

 were several times greater. From Lake Michigan alone, in 1880, the catch was 3,839,600 

 pounds (jj: 26). Lake of the Woods (Minnesota and Canada) was formerly called 

 "the greatest sturgeon pond in the world"; the catch there in 1893 was 1.6 million 

 pounds (29: 121-136). 



In the St. Lawrence River, from the Ontario border to Cap St. Ignace at Quebec, 



30. Harkness (jS: 28, 29) has given references to other authors who studied food requirements oi A.ful'vescens from 

 various localities. 



