No. 430.] THE COLORS OF FISHES. 805 
Protective Markings. —The markings of fishes are of almost 
every conceivable character. They may be roughly grouped 
as protective coloration, sexual coloration, nuptial coloration, 
recognition colors, and ornamentation, if we may use that term 
for brilliant hues which serve no obvious purpose to the fish 
itself. 
Examples of protective markings may be seen everywhere. 
The flounder which lies on the sand has its upper surface cov- 
ered with sandlike blotches, and these again will vary according 
to the kind of sand it imitates. It may be true sand or crushed 
coral or the detritus of lava, in any case perfectly imitated. 
Equally closely will the markings on a fish correspond with 
rock surroundings. With granite rocks we find an elaborate 
series of granitic markings, with coral rocks another series of 
shades, and if red corals be present, red shades of like appear- 
ance are found on the fish. Still another kind of marks indi- 
cates rock pools lined with the red calcareous alge called 
Corallina. Black species are found in lava masses, grass-green 
ones among the fronds of ulva, and olive-green among Sargas- 
sum or fucus, the markings and often the form corresponding 
to the nature of the algz in which the species makes its home. 
Sexual Coloration. — In many groups of fishes the sexes are 
differently colored. In some cases bright red, blue, or black 
markings characterize the male, the female having similar 
marks, but less distinct, and the bright colors replaced by olive, 
brown, or gray. In afew cases, however, the female has marks 
of a totally different nature, and scarcely less bright than those 
of the male. , 
Nuptial Coloration. — Nuptial colors are those which appear 
on the male in the breeding season only, the pigment after- 
wards vanishing, leaving the sexes essentially alike. Such 
colors are found on most of the minnows and dace (Cyprinidz) 
of the rivers and to a less degree in some other fresh-water 
fishes, as the darters (Etheostominz) and the trout. In the 
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. 
