830 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



with a hook, causes a small extrusion of ovaj but I have not noticed 

 the males to drop their milt. 



The yellow perch appears to be equally at home in quite different 

 localities. As a still-water pond fisb, if there is a fair supply of spring- 

 water, they thrive excellently; but the largest specimens we have met 

 with were either from the river or from the mouths of the larger in-flow- 

 ing creeks. I believe that for the adult fisb, deep water, of the tempe. 

 rature of ordinary spring-water, having some current, and the bed of 

 the stream, at least, partially covered with vegetation, is about such a 

 locality as best suits this fish ; this belief being based upon my expe- 

 rience in seeking out localities that afforded good sport in taking them 

 with a line. Occasionally we have taken them of very large size in 

 quite shallow waters. In such cases, it was evident that they were 

 then following small cyprinoids, to feed upon them. When not in pur- 

 suit of food, they seek the deepest waters of the stream, preferring it to 

 be of a depth of 10 feet, at least. Here they remain, quiet and close 

 to, if not resting upon, the bed of the pond or stream. In streams of 

 very clear water, we have occasionally seen numbers of perch resting 

 apparently upon the bed of the stream, side by side, and all with their 

 heads up-stream, just as, in August, we have seen a closely packed, 

 crimson mass of "red-fins" (Hypsilepis cornutus) in a deep basin of some 

 rapid mountain-brook. 



The yellow perch is what may be called semi-social. Without going 

 in schools, as do the herring ; they are usually found in considerable 

 numbers; associated, as it appears to me, more because the character 

 of the locality is attractive to them, than from any pleasure in associat- 

 ing with their own kind. This is one of those impressions that a close 

 observer will get, without being able to point out any one or more pecu- 

 liarities in their habits which seem to prove it true. At all times they 

 freely associate with other percoids, in the same manner as with indi- 

 viduals of their own kind, and follow, when hungry, associated with 

 rock-fish {Boccus Uncatus) and white perch {Morone americana), the scat- 

 tered schools of cyprinoids, on which all three of these fishes so largely 

 prey. The food of the perch, in fact, seems to be exclusively minnows. 

 I have never detected any other food, except earth-worms, or an occa- 

 sional grasshopper or cricket; these latter, however, may be considered 

 as accidental articles of food. Probably, too, every spring, they feed 

 to some extent upon their own ova and those of other fishes ; but we 

 have found that the water- turtles, especially the plain and spotted tur- 

 tles {Calemys mulilenbergii and Nanemys guttata)^ are the worst enemies 

 that fish have — i. e. — at any rate suckers breed in small streams. 



In feeding, yellow perch chase small minnows, instead of waiting for 

 a single fish to come near enough to seize by a single dart upon it, as 

 the pike does. In catching the minnows, they are not rapid in their 

 movements, but seem to dart with open mouth at several minnows, as 

 though trusting to catch some one of the number they pursue. While 



