122 
BULLETIN OF THE BUKEAU OF FISHERIES 
The carp is omnivorous, but its principal food probably consists of plants. Hessel (1878, p. 865) 
says: “ The carp lives upon vegetable food as well as upon worms and larvae of aquatic insects, which 
it turns up from the mud with the head; it is very easily satisfied and will not refuse the offal of the 
kitchen, slaughterhouse, and breweries, or even the excrement of cattle and pigs.” Three stomachs 
examined by Linton from specimens taken at Havre de Grace, Md., contained only vegetable matter, 
mostly the fruit of eelgrass. 
In this country the carp has not infrequently been accused of destroying our native fishes. 
In some localities this has become a popular belief, but investigators have been unable to find much 
incriminating evidence. It is a well-known fact that since the introduction of the carp our native 
fishes have become fewer in many streams, and that the carp is becoming abundant. A very 
natural and logical conclusion, with such evidence alone at hand, is that the carp is responsible for 
the decrease of the native species. It must be remembered, however, that a similar decrease has 
taken place in many of our marine fishes. For such decrease other causes must be sought, as no 
introduction of foreign species of strictly marine fish has taken place. It is not argued that the 
carp does not at times, through the uprooting of vegetation, destroy nests of other fish, nor that it at 
times eats the spawn of other fish, or that it destroys some of the young fish of other species; on the 
other hand it must be remembered that our native species, too, prey upon each other and upon the 
carp, very probably to a much greater extent than the carp preys upon them. The carp, being 
largely herbivorous, gains much of its sustenance from plants; whereas many of our native fishes 
are strictly carnivorous, requiring animal foods, and where the young carp is present it not infre- 
quently furnishes a considerable portion of the food of the carnivorous fishes. From this standpoint 
the presence of carp appears to be a distinct advantage. It seems necessary, in the light of our pres- 
ent knowledge, to seek the reason for the decline in our fresh-water food fishes elsewhere. For a 
complete and admirable account of the carp and the various accusations that have been made against 
it in America see the report of the Bureau of Fisheries for 1904, pages 523 to 641, under the title 
“ The German carp in the United States,” by Leon J. Cole. Overfishing, fishing during the spawning 
season, the construction of obstructions in streams (prohibiting the free passage of fish to and from 
their natural spawning and feeding grounds) , and, most important of all, the pollution of streams are 
undoubtedly the important factors in bringing about the diminution of our native food fishes. 
The carp prefers rather quiet waters that support an abundance of vegetation, but it is not 
limited thereto, as it is not infrequently taken in rather swiftly flowing streams. Although the 
carp is essentially a fresh-water fish, it does enter brackish water, and in the Old World, according 
to Hessel (1878, p. 869), it even frequents salt water. In the Chesapeake the carp is found abun- 
dantly in fresh water, sparingly in brackish water, but not at all in the salter parts of the bay. 
Spawning takes place in the spring and may extend over a considerable period of time. The 
eggs are deposited among vegetation; they are adhesive and usually adhere to vegetation in lumps. 
Field notes made by Lewis Radcliffe state that the ovaries of 4 to 5 pound carp contain from 
400,000 to 500,000 eggs and that a 16H-pound fish contained ovaries weighing 5 pounds with 
over 2,000,000 eggs. During warm weather the eggs hatch in from 12 to 16 days. Under favor- 
able conditions the young grow rapidly. Hessel (1878, p. 873), in speaking of carp culture in 
Europe, says: “The normal weight which a carp may attain to in three years, whether it be scale 
carp, mirror carp, or leather carp, is an average of from 3 to 3 x /i pounds; that is, a fish which has 
lived two summers, consequently is 18 months old, will weigh 2% to 3 34 pounds the year following.” 
The carp is said to attain a great age — 100 to 150 years — and a weight of 80 to 90 pounds, but such 
statements generally are based upon insufficient evidence. Hessel (1878, 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.” Smith (1907, p. 106) 
makes the following statement: “The carp attains a relatively large size, examples weighing up- 
ward of 60 pounds being known in Europe and fully 40 pounds in the United States, although full 
sexual maturity is attained by the second or third year, when the fish weigh only 3 or 4 pounds.” 
The following weights were secured: Length, 17 inches, 2 pounds 12 ounces; 20 inches, 
4 pounds 8 ounces; 22J4 inches, 6 pounds 5 ounces; 26 inches, 9 pounds 3 ounces. 
Habitat . — Temperate Asia; introduced into Europe, Java, England, United States, Canada, 
Mexico, Costa Rica, Ecuador, the Hawaiian Islands, etc. 
