BREEDING BEHAVIOR OF SUCKERS AND MINNOWS. 13 



males separate, the red stripe on their sides and the red in their 

 eyes fades, but the white occipito-lateral stripe remains for 

 some time. Each male now moves about and feeds as before. 

 And so they continue until another female appears when one or 

 both may succeed in pairing with her and this may happen 

 on any part of the spawning ground. Thus the eggs fertilized 

 by one male may lie anywhere in the gravel of a rapid or in that 

 of several rapids. The breeding activities are in no way centered 

 about individual males, for the cooperation of two males in 

 pairing makes it impossible to know what eggs are fertilized by 

 an individual male. 



I have never collected from the bottom the eggs laid at a 

 single pairing. But the smaller fish lurking in the neighborhood 

 tell one plainly enough where they are. The black-nosed dace 

 (Rhinichthys atronasus) and the rainbow darter (Etheostoma 

 coeruleum) gather at once in great numbers over the spot where 

 the pairing suckers were. They come in a straight line from 

 down stream attracted, no doubt, by the trail of milt, eggs or 

 bottom materials swept down by the current. They gather in 

 an area six or eight inches across and each burrows in the bottom 

 with its snout as though seeking eggs. The whole little area is 

 soon concealed by their wriggling tails, close-set like threads in 

 the pile of velvet. Some of the eggs may have been swept down 

 stream, but many of them must be buried where the small fish 

 are rooting. 



When more than two males follow a female (Fig. 4) it may be 

 difficult to see what happens. When she finally stops the two 

 males nearest or most vigorous in the pursuit attempt to pair 

 with her. But the others at once crowd about and try to force 

 their way between her and her mates. They try either to squeeze 

 in at the sides of the female from above so as to force her mates 

 outward, or to wedge themselves beneath the pairing males 

 from the side so as to force them up and take their places. But 

 once the two males have the female firmly held between them 

 it is difficult to dispossess either and I have never seen this 

 happen. As many as ten males have been seen with a single 

 female during the spawning act, and the act was nevertheless 

 completed; but often, when many crowd about, she interrupts 



