400 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
better grasses. Many of the clubs planted wild celery in 1891, 1892, and 1893, but the carp destroyed 
it all, and it is claimed by observing men that the celery is entirely destroyed. The clubs resort 
every season to baiting their ponds with grain, and in these ponds the carp move in droves that W. P. 
Whittier tells me look like a tidal wave, as they move from one side to the other. 
The following observations on the food and the feeding-habits of the carp have been 
furnished by Dr. Rudolph Hessel, who superintended the first importation of German 
carp by the Government in 1877, and the foremost authority in the United States 
on carp-culture. Dr. Hessel’s remarks were prompted by the letter of Mr. Wilson 
previously quoted, an extract from which was submitted for an expression of opinion. 
In connection with an extract from a letter of Mr. Ramon E. Wilson, California fish commission, 
relating to the snsjmcted destruction of wild celery and other vegetation in the Suisun Marshes in the 
vicinity of San Francisco, Cal., by the carp, I will give you my observations, extending over a period 
of many years, regarding the habits of the carp (if I may be allowed to so term its mode of living, 
and the likes and dislikes of that fish), cautioning you, however, not to regard such observations as 
authority. 
It is true that I have paid a great deal of attentiou to the habits of the carp iu Europe and in our 
eastern waters, but I am not familiar with the waters of the Pacific Coast, and, for this reason, my 
conclusions should not be taken as final. 
It is well known that the carp is not very particular as to its food. It feasts upon animal as well 
as upon vegetable food. It seems to be an established fact, however, that animal food is preferred, 
lienee their persistent hunt iu the mud and about the roots of water plants for worms, Crustacea, and 
larvai. At the earliest stages of its existence, from a few weeks to a few months old, the young carp 
can be seen scrutinizing water grasses and the under parts of floating leaves, etc., for diminutive and 
almost microscopic animals for feeding purposes. Later on they do not despise larger animal substances 
in the rivers; but where there is a perceptible scarcity of that kind of food in rivers and stagnant 
waters, they ascend into tributaries, creeks, and bayous, ostensibly going for vegetable food, in reality, 
however, delving, digging, burrowing, and hunting in the mud and about the roots of the water vege- 
tation for animal food, as indicated above. No one need, therefore, be surprised if at such vigorous 
exertions of the carp the growth of vegetation generally will not be promoted and the water will not 
become any clearer. Many a plant will thus be uprooted, rise to the surface, and perish, and this may 
have been the case with the celery plants in the Suisun Marshes, too, to a certain extent. 
The carp is very numerous and prolific in the Potomac River. There are specimens from 20 to 30 
pounds, but that they go for the water celery has not been noticed here as yet. Water celery grows 
in abundance in places where the river flows slowly, especially about the so-called flats, but any injury 
to its growth, or a reduction of its density, not to speak of its total destruction, has not been heard of, 
as far as I know, with two exceptions only, not attributable, however, to the carp, but to high water 
in the spring of 1882 and 1889, when every kind of vegetation was swept away by the floods, and con- 
sequently water celery disappeared from the river during the two years subsequent to those freshets. 
I must not forget to call your attention to the fact that turtles, too, are not averse to a meal of 
water celery. Frequently I have seen “red-bellies” and “yellow-bellies” feasting in the dense 
growth of Potomac celery upon that plant. Another point: For years I have kept quite a number of 
these species of turtles for ornamental purposes in a small pond about this station and fed them with 
water celery taken fresh from two ponds stocked with a great number of old and young carp, which 
never touched the celery, though it must be admitted that they did loosen the roots in their hunt for 
animal food. 
In conclusion, I reiterate that I am not familiar with the fauna of the Suisun Marshes, but my 
impression is that, upon closer investigation, there may perhaps be found additional causes for the 
disappearance of the water celery and other vegetation therein, besides the undeservedly much- 
abused carp. 
The carp may be very destructive to the spawn of certain fishes; this is probably 
the most serious charge that can be lodged against it. At the same time, no exami- 
nations, by competent persons, of the stomach contents of carp appear to have been 
made in the Pacific States or elsewhere. Even if it should be demonstrated that the 
carp consumes large quantities of fish spawn, it would not differ in this respect from a 
host of native species whose shortcomings in this respect are usually overlooked. If 
