84 The Colors of Fishes 
minnows of many species the male in spring has the skin charged 
with bright pigment, red, black, or bright silvery, for the most 
part, the black most often on the head, the red on the head 
and body, and the silvery on the tips of the fins. At the same 
time other markings are intensified, and in many species the 
head and sometimes the body and fins are covered with warty 
excrescences. These shades are most distinct on the most vigor- 
Fia. 66.—Blue-breasted Darter, Etheostoma camurum (Cope), the most brilliantly 
colored of American river-fishes. Cumberland Gap, Tennessee. 
‘ous males, and disappear with the warty excrescences after the 
fertilization of the eggs. 
Nuptial colors do not often appear among marine fishes, and 
in but few families are the sexes distinguishable by differences 
in coloration. 
Recognition-marks.— Under the head of ‘‘recognition-marks”’ 
may be grouped a great variety of special markings, which may 
be conceived to aid the representatives of a given species to 
recognize each other. That they actually serve this purpose is 
a matter of theory, but the theory is plausible, and these mark- 
ings have much in common with the white tail feathers, scarlet 
crests, colored wing patches, and other markings regarded as 
recognition-marks among birds. 
: Among these are ocelli, black- or blue-ringed with white or 
yellow, on various parts of the body; black spots on the dorsal 
fin; black spots below or behind the eye; black, red, blue, or 
yellow spots variously placed; cross-bars of red or black or green, 
with or without pale edges; a blood-red fin or a fin of shining 
blue among pale ones; a white edge to the tail; a yellow, blue, 
cr red streamer to the dorsal fin, a black tip to the pectoral 
