528 KEPORT OF THE COMMISSIONER OF FISHERIES. 



uniform courtesy. Through the kindness of Prof. Herbert Osborn 

 1 was enabled, when in Sandusk}", to make my headquarters at the Lake 

 Laboratory" of Oliio State University, where 1 had the use of a table 

 for considerable periods during the summers of 1901 and 1902. And, 

 finall}', I wish to express my gratitude to the many fishermen who 

 took great interest in my work, who gave me whatever information 

 was at their disposal, who permitted me to accompan}'^ them on their 

 fishing trips, who shared with me their food, and who were my com- 

 panions in camp for weeks at a time. Other special acknowledg- 

 ments have been made in their proper places throughout the report. 



THE SPECIES CYPRINUS CARPIO LINN.EUS. 

 DESCKIPTION. 



Within the past decade the carp has become so generally distributed 

 throughout the United States and so abundant in some places that 

 nearh* ever3"l)ody is more or loss familiar with it in a general wa}^, but 

 it has been almost universally neglected in the descriptive works in 

 this country, further than a simple statement of its occurrence. It 

 may therefore be well to give a brief description of the carp and its 

 principal varieties. 



The carp belongs to a famil}^ of fishes (Cyprinida.^) best represented 

 in America by the minnows (especially of the genus JV(jfroj)/'s) which 

 abound in most of our lakes and streams. In the eastern United States 

 the members of this family are all small, the largest rarely attaining 

 18 inches in length, while the smallest is scarcely 2 inches long 

 when adult. The Old World species are generally much larger than 

 this, and on the Pacific coast there are a few which reach a length of 

 5 or 6 feet, and which are also apparentl}" more closely related to the 

 European forms in structure. 



Scientifically the carp is known as Cyprlnus carplo^ the name given 

 to it by Linnfeus. It varies greatly in many of its characters, a con- 

 dition probabl}" brought about in large part by its state of domestica- 

 tion, or semidomestication, for a number of ceirturies. In shape it 

 varies from a long, rather slender fish (pi. i), whose height scarcely 

 equals one-fourth its length, to a deep form nearly or quite half as 

 high as long. The greatest height is at the anterior end of the dorsal 

 fin. In all cases, however, the body is rather strongly compressed 

 laterally, the cross section never approaching close to circular. The 

 greatest breadth is normally a short distance back of the head, but the 

 bodies of female fish are often, before the breeding season, distended 

 with roe to a considerably greater breadth. This dimension in nor- 

 mal individuals usually equals less than half the height. The snout is 

 blunt, and in typical forms the dorsal outline rises from the snout in 

 a nearly uniform bow or arch to the base of the dorsal fin. 



