NOTES ON TWO AMERICAN WHITEFISHES. 
11 
of the long-jaws examined by him has consisted mostly of a small crustacean, resem- 
bling a crab, with a soft shell. This is probably a ilysis. 
One of the most interesting and important questions suggested by the presence 
of this whitefish in Lake Ontario in large numbers is the relation which it may have 
to the present scarcity of the regular whitefish. It is no doubt i^ossible that the 
uninterrupted increase of this prolific fish during a long period of years might finally 
have resulted in the depletion of the natural-food supply of the whitefish to such an 
extent that the common whitefish, being munerically and physically weaker, were 
forced to seek other feeding-grounds, which may have been much restricted and in 
such situations that it was taken by man more easily than formerly, and so more 
rapidly caught up. The exhaustion of the food would also affect unfavorably the 
growth and survival of young whitefish. Mr. Wilson’s observations confirm this 
theory; he states that the first year after the appearance of the long-jaws the 
regular whitefish, which had been abundant, became very scarce, and at the present 
time are so rarely taken as to be almost a curiosity, the explanation assigned by him 
and others being that both fish fed on the same food, on the same grounds, and at 
the same time. 
In some of the specimens of this whitefish at hand parasites have been found, to 
which reference may appropriately be made, although the uufamiliarity of the writer 
with the subject precludes an entirely satisfactory discussion of the animals in ques- 
tion. In the gill cavities of a number of the fishes received from Wilson, N. Y., iu 
April, small crustaceans about one-half of an inch long, belonging to the order of 
copepods, were discovered fastened to the gill arches and the under surface of the 
opercle. Some of the parasites were sent to Prof. R. Ramsay Wright, of the biological 
department of the University of Toronto, who has contributed extensively to the 
literature of the parasites affecting fresh-water fishes; he courteously examined the 
specimens and reported as follows : 
I should regard it as identical with the form described and figured by Kellicott (Proc. Amer. 
Soc. Microscopists, 1878) as the gill herring-sucker, and named Achtheres oorpiilentus. He also figured a 
Lernwopoda from the whitefish, but this agrees with Achtheres in the curved egg sacks, stalked sucker, 
and form. It appears also to have some indications of segmentation iu the abdomen, which Leriuvopoda 
ought not to have. 
Among the matured ova expressed from specimens received iu June a consid- 
erable number of trematode worms of the genus EcMnorhynclms were found. As the 
usual habitat iu fishes of the numerous members of this genus is the intestinal tract, 
it is not iH’obable that these parasites came from the ovary, althoitgh found among 
the eggs. 
COMMERCIAL IMPORTANCE AND FOOD VALUE OP THE LONG-JAW WHITEFISH. 
Information is lacking to show that this whitefish has ever been a special object of 
fishery or at present has any commercial importance, except in lakes Michigan and 
Ontario, although it is probable that additional inquiries will disclose the fact that in 
the other lakes the fish is caught in greater or less quantities, but is peihaps not gen- 
erally distinguished from the closely related lake herring. 
In Lake Ontario this is now one of the most important commercial fishes. At some 
fishing centers it is more valuable than all other fish combined. It never approaches 
near enough to the American shores to be caught iu seines or with any of the fixed 
forms of apparatus, and is taken only in gill nets set at the bottom in deep water. 
