THE GEEMAF CAKP IN THE UNITED STATES. 535 



become well established." This is a matter of considerable importance, 

 for whatever may be our opinion of the carp as a food fish^ we cer- 

 tainly do not want it any poorer than it is. For this reason it would 

 seem that efforts should be made to prevent the introduction of the 

 crucian carp iu our waters, and to restrict, so far as possible, the 

 spread of gold-lish, teuch, and other fishes with which the carp may 

 hybridize with a resulting deterioration of the food value of the race. 



SIZE, GROWTH, AND AGE.^ 



There appears to be but little definite information as to how long 

 carp maj" live, and w^hat size the}" may attain. It is said that the}^ 

 may live to be 100 or even 150 3'ears old, and may come to weigh 80 

 to 90 pounds, but these statements are generally based upon insuffi- 

 cient evidence. That the fish do commonly reach a weight of SO to 40 

 pounds, however, seems quite certain, and Hessel (1881, p. 874) says: 

 ''It is a well-known fact that two largo carps, weighing from 42 to 55 

 pounds, were taken several years ago on one of the grand duke of 

 Oldenburg's domains in Northern Germany," and also claims to have 

 had in his possession some scales 2i inches in diameter, which came 

 from a Danube carp that weighed 07 pounds. 



The largest carp I have myself seen from the Great Lakes would 

 not weigh much over 20 pounds. That the fish do attain a much larger 

 size is, however, certain. Mr. ^Y. Cleaver, upon whose information 

 1 can relj', tells me that in the spring of 1903 he received from San- 

 dusky Ba-y a female carp which weighed 30 pounds after spawning. 

 According to the ratio between the weight of the ova and the entire 

 weight of the fish found in another case, before spawning this fish 

 would have weighed, in all probabilitj^, fully 37 pounds. From the 

 fishermen, both at Lake St. Clair and at Lake Erie, 1 often heard of 

 carp weighing 30 and 40 pounds, but these were only estimates and 

 not based on actual figures. That there are at present to be found in 

 these waters carp weighing more than 40 pounds 1 doubt. 



As has alread}" been stated, the rate of growth of carp (as is true of 

 most fishes) depends in a great measure upon the temperature of the 

 water in which the fish lives and the abundance of suitable food. Under 

 ordinary conditions in open waters of temperate regions the}^ will 

 reach a weight of 3 to 3i pounds in three years (Hessel, 1881, p. 873), 



aGoorle (1888, p. 418) says the tench has become well aeclimatiEed in the Potomac. Dr. H. M. 

 Smith, however, informs the writer that the tench is not numerous in the Potomac, but the gold-fish 

 is abundant and has become one of the regular market fishes at Washington. It has lost the brilliant 

 coloration it had when it escaped from the Government ponds, and now has the dull brown color of 

 the primitive type; the fish is not recognized in the market, and is sold under the name of "sand 

 perch." 



bit is maintained that the age of carp may be told with considerable accuracy by means of the 

 successive lines of growth upon the scales, similarly to the way tiiat the age of a tree is determined 

 by counting the annular rings. Persons interested in this subject will find a full discussion of it by 

 Dr.'Emil Walter in the book on carp-culture by Knauthe (1901), chapter iii, pp. 88-1^:2, "Die Alters- 

 bestimmung des Karpfens nach der Schuppe." 



