THE GERMAN CARP IN THE UNITED STATES. 55 
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 
erucian carp in our waters, and to restrict, so far as possible, the 
spread of gold-fish, tench, 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 may live, and what size they may attain. It is said that they 
may live to be 100 or even 150 years old, and may come to weigh 80 
to 90 pounds, but these statements are generally based upon insufli- 
cient evidence. That the fish do commonly reach a weight of 30 to 40 
pounds, however, seems quite certain, and Hessel (1881, p. 874) says: 
‘It is a well-known fact that two large 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 24 inches in diameter, which came 
from a Danube carp that weighed 67 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. W. Cleaver, upon whose information 
I can rely, tells me that in the spring of 1903 he received from San- 
dusky Bay 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 probability, fully 87 pounds. From the 
fishermen, both at Lake St. Clair and at Lake Erie, I 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 I doubt. 
As has already 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 they will 
reach a weight of 3 to 3X pounds in three years (Hessel, 1881, p. 873), 
\ : : 
aGoode (1888, p. 418) says the tench has become well acclimatized 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 eseaped 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 that 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 earp-culture by Knauthe (1901), chapter U1, pp. 88-122, ‘‘ Die Alters- 
bestimmung des Karpfens nach der Schuppe.” 
