Biological Survey — Oswego Watershed 77 



and fragments of water plants. Intestine (in order of frequency 

 of occurrence ) ; small snail shells and fragments ; caddis worm 

 cases ; midge larvae ; amphipods ; copepods ; ostracods ; legs and 

 antennae of various Crustacea; filamentous algae; small mollusca; 

 cladocera. Second specimen. Length, 21 inches; weight, 6 lbs; 

 age, 5 years ; stomach empty ; intestine : snail shells and fragments ; 

 midge larvae ; caddis worm cases ; plant fragments ; ostracods ; clad- 

 ocera; amphipods; small clams. Third specimen. Length, 21 

 inches ; weight, 8 lbs ; male ; contents of stomach : caddis worm 

 cases ; snail shells ; midge larvae ; plant fragments and stalk frag- 

 ments; ostracods; 3 fish scales; w^ter mites; plant leaf; minute 

 algae ; crustacean legs. 



To test out the report that carp destroyed plants, a cage was 

 constructed at Three Mile bay. Three adult carp were confined 

 for two months in this wire screened cage covering an area of 

 about 25 square feet. At the close of the experiment a few plants 

 of eel-grass had been uprooted but there remained a large num- 

 ber of these plants and others which carp are reported to root up 

 in feeding. The cage was located in a place where carp had been 

 found to congregate and after the cage was constructed carp were 

 repeatedly seen in the weeds close to the cage. The conditions 

 then, were as near ideal for testing out this question as possible, 

 and the result indicates that the damage done to vegetation was 

 insignificant; but on the other hand the detailed studies on the 

 food of adult carp in Oneida lake clearly indicate their preference 

 for animal food. 



Cole states that the food is largely vegetable. Tracy 1 reporting 

 on Rhode Island fisheries says that the carp eat principally vege- 

 table matter; and Forbes and Richardson 2 emphasize vegetable 

 food as the main constitutent. It is hardly to be expected that there 

 would be such a marked difference in the food habits of the Oneida 

 lake carp. The explanation may be in the fact that our material 

 was preserved very soon after the fish were caught, The studies of 

 this summer indicate that animal food predominates and that 

 there is some selection in the animals eaten. The finding of 

 muscle fragments and fish scales is rare and probably means that 

 they were taken in with the debris that is so characteristic of the 

 intestinal contents. 



The Habits of the Young Carp. — Up to the present time prac- 

 tically nothing has been known about the habits of young carp. 

 This is probably due in part to their hiding in vegetation when 

 disturbed rather than exposing themselves in an attempt to escape. 

 Moreover they do not live in schools as do many of the young 

 game fishes, a characteristic which causes them to escape the notice 

 of a casual observer. It is easy to distinguish carp fry from the 

 young of other fishes for they are a replica of the adult in form 



"Tracy, H. C. Annotated list of fishes known to inhabit the waters of 

 Rhode Island. Com. Inland Fisheries, R. I., 1910. 



2 Forbes, S. A. and Richardson, R. E. The Fishes of Illinois. 111. State Lab. 

 Nat. Hist., vol. 3, 1908. 



