BREEDING BEHAVIOR OF SUCKERS AXU MINNOWS. 5 



here an'd there in the rapid on the patches of cleaned gravel 

 and were seen to take gravel into the mouth and spit it out. 

 They were presumably in quest of eggs that had been laid in 

 the disturbed gravel areas and their occurrence in small groups 

 is perhaps in part the result of the distribution of such areas. 

 In their search they were accompanied by numerous small 

 minnows doubtless on the same quest. Other suckers were 

 seen crossing the pipe-line. At four o'clock no suckers were to 

 be seen from the bridge, but a dozen were found just below the 

 dam an eighth of a mile further up stream. The fish had appar- 

 ently covered this distance in an hour. At nine o'clock the 

 same evening the search light showed suckers still crossing the 

 pipe line bound up stream. 



In my experience the white sucker is one of the most difficult 

 of our native fishes to approach in the open. Ordinarily it 

 becomes accustomed to the observer with extreme slowness and 

 at no time permits him any great freedom of movement. Con- 

 fined with other fish in an aquarium it is among the last to 

 become accustomed to the observer or to take food. 1 



1 I have noted but two exceptions to this general fact, (i) On May 6, in the 

 morning, I placed in an outdoor aquarium at the Mill Creek Hatchery four males 

 and two females that had been captured in a seine on the previous evening. At 

 three o'clock on the same day the fish were moving about and feeding and by four 

 o'clock they were spawning. They did not react to an observer within two or 

 three feet of them. (2) At Douglas Lake in Cheboygan County, Michigan, suckers 

 are found in rather deep water. At night they come into shallower water to feed 

 and are occasionally seen there at dawn. At such times they flee to the deeper 

 water at the first glimpse of a moving object. lu late June the log perch (Percina 

 caprodes) are laying their eggs in the sand in very shallow water. At that time 

 suckers enter shallow water in the day time and feed on the eggs of the log perch. 

 Each sucker is accompanied by a group of log perch which appear to be feeding on 

 eggs uncovered by him and perhaps on other crumbs from his table. At this time 

 the suckers may be approached with little trouble and I have come close enough 

 to photograph them as they lay at my feet. I have thought this absence of the 

 suckers' usual wariness due to the presence of the log perch. These are breeding 

 and are then unafraid. In deeper water the sucker has probably found freedom 

 from disturbance where they were present. Safety and log perch have been closely 

 linked in his experience. So now, so long as the log perch are on the shallows, he 

 is not easily startled and feeds there undisturbed by sights that would otherwise 

 send him hurrying to shelter. 



To these observations may be added one of Smallwood (unpublished notes). 

 At the end of June he found Catostomus commersonii and two other species of 

 sucker on stonv bottom in the shallow water of Lake Clear in the Adirondacks. 



