186 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Milner, whose studies of the Great Lake fishes were the most complete ever made, 
writes as follows on this question : 
Their [the sturgeons’ ] food consists almost entirely of the shellfish of the lakes, principally gas- 
tropods, the thinner-shelled kinds of the genera Pliysa, Planorbis, and Valvata being found broken 
in the stomachs, while Limncea and Melantlio remain whole. A few eggs of fishes have been found at 
different times, but examination of stomachs during the spawning season of the most numerous fishes 
did not prove them to be very extensive spawn-eaters.* 
A few observations can be recorded which are thought to add to the published 
information on this subject. In June, 1891, a sturgeon weighing 150 pounds was taken 
at Osjvego, New York, which was found to be filled to its utmost capacity with wheat. 
The fish had evidently been feeding under the grain elevators on the Oswego River. 
Individual specimens are also occasionally caught in Lake Ontario with corn in tbeir 
stomachs. A favorite food at times is the crayfish, which occurs abundantly in the 
lake and is commonly known as the “crab” among fishermen; sturgeon have been 
eviscerated at Oswego and elsewhere with large quantities of this crustacean in their 
alimentary tracts. The fishermen often use these “ crabs” as bait on their set lines 
and secure fish when all other kinds of bait fail to attract them. The fondness of the 
male fish for sturgeon spawn has been repeatedly attested. 
Prof. John A. Ryder, in his able paper on “ The Sturgeons and Sturgeon Indus- 
tries of the East Coast of the United States,” etc.,t shows that the food of the young 
sturgeons consists chiefly of minute animal forms of great variety; as the fish become 
more mature, larger organisms, principally worms and crustaceans, are taken, and the 
full-grown fish often resort to mollusks of considerable size. Summing up his obser- 
vations, the writer says : 
The story of the life of a sturgeon is therefore seen to be bound up with the lives of vast myriads 
of organisms in no way related to it in the system, but only as sources of nutriment. It is quite 
certain from what has preceded that if the minute life upon which the young sturgeons subsist were 
exterminated, the sturgeon would also become extinct. It follows from this that whatever affects the 
relative abundance of the minute life of the rivers and estuaries where sturgeons are found must also 
affect the survival and abundance of the latter. The importance of a study of all the organisms upon 
which the sturgeon is directly or indirectly dependent must therefore be obvious to everyone. The 
legitimacy of the inquiries into the life histories of all organisms, even those in no way directly related 
to the economy of the State, should therefore need no apology from those engaged in the study of the 
problems of economic fish-culture. 
The food value of tlie sturgeon is yearly becoming more fully appreciated on tbe 
lakes as tbe supply becomes scarcer, and it is only a question of time under existing 
conditions when tbe demand for tbe fisb will far exceed tbe yield of tbe fishery. Tbe 
necessity not only of perpetuating but of increasing tbe abundance of tbis species 
in Lake Ontario needs no demonstration. Mention bas already been made of tbe rela- 
tively bigb price commanded by tbe fisb in comparison witb other commercial species ; 
but tbe economic importance of tbe sturgeon is not only in its flesh, for such valuable 
secondary products as caviare, glue, isinglass, oil, and fertilizer are made from it, and 
tbe skin is capable of being converted into a valuable leather. 
Tbe question which presents itself is, How shall tbe supply of sturgeon in Lake 
Ontario be preserved? It is suggested (1) that legal restrictions should be placed on 
* Report U. S. Fish Commission, part ii, 1872-73 t Bulletin U. S. Fish Commission, vm, 1888. 
