THE GERMAN CARP IN THE UNITED STATES. 579 



our Southern States the development is more rapid; in a pond in Geor- 

 gia, when the temperature of the water was 69°, the eggs are reported 

 to have hatched in five to six days. while the following } r ear, with the 

 water still warmer, the whole time consumed for development was but 

 forty-eight to seventy-two hours (statement of H. H. Carey, M. D., 

 Smiley, 1886, p. 687). The young fish also grow very rapidly and in 

 the latitude of Lake Erie reach a length of 1 to 6 inches the first fall. 



DISEASES, PARASITES, AND ENEMIES OF THE CARP. 



The most remarkable fact in this connection seems to be that. 

 although deformed and misshapen individuals are b\- no means rare, 

 carp in the Great Lakes region appear to be very strong and hardy 

 and almost free from diseases, whether such as are due to parasites 

 or to other causes. This fact impressed me especially while I was 

 working with them in the fish houses on Lake Erie, where I had a 

 good opportunity to compare them with large numbers of other lake 

 fishes. One finds intestinal parasites in almost any of the other species 

 in great abundance, but in large numbers of carp examined I have 

 found parasites in the alimentary tract in only one case. This was a 

 rather large fish, which had some 16 round worms, nearly chrome 

 yellow in color and 2 to 2.5 cm. (four-fifths inch to 1 inch) long, hang- 

 ing to the walls of the intestine. Their spiny probosces were buried 

 in the intestinal wall in true acanthocephalous fashion, and it required 

 a considerable pull to detach them. These specimens were referred 

 to Mr. H. W. Graybill, who studied the parasites of many of the 

 Lake Erie fishes in 1901. Mr. Graybill reports that these are a form 

 closely related to JEcMnorkynchus proteus, though he thinks they are 

 possibly specifically distinct from that type. He further states that 

 in 1901 he found in a carp a single dwarf specimen of the same worm. 



Excrescences of the integument, probably caused by sporozoa, are 

 not infrequent on the wall-eyed pike {Stizostediori), and were occa- 

 sionally found on other species, but I did not observe them at all on 

 carp. 



In one case I found a leech attached to the base of one of the pec- 

 toral fins of a carp, but unfortunately the specimen was lost before it 

 could be preserved, so that I have been unable to have it identified. 

 The only Lake Erie fishes on which 1 observed letches at all commonly 

 were the lake lawyer {Lota maculosa) and some of the cat-fishes (espe- 

 cially Ictalurus). 



There can be no doubt that the lampreys must also be considered 

 among the external parasites of the carp, though I have never myself 

 seen one attached to a carp. The fishermen told me that ' ' lamper eels " 

 were " common " up the Portage River, and I often found them among 

 the fish brought to the wholesale house from both the river and the 



