164 Series Ostariophysi 
they may be hooked at tip in those which eat smaller fishes; 
they may be serrated or not; they may have an excavated 
‘‘srinding surface,” which is most developed in the species which 
feed on mud and have long intestines. In the Cyprinidae, or 
carp family, the barbels are small or wanting, the head is naked, 
the caudal fin forked, the mouth is toothless and without suck- 
ing lips, and the premaxillaries form its entire margin. With 
a few exceptions the Cyprinide are small and feeble fishes. 
They form most of the food of the predatory river fishes, and 
their great abundance in competition with these is due to their 
fecundity and their insignificance. They spawn profusely and 
find everywhere an abundance of food. Often they check the 
increase of predatory fish by the destruction of their eggs. 
In many of the genera the breeding color of the males is 
very brilliant, rendering these little creatures for a time the 
most beautifully colored of fishes. In spring and early summer 
the fins, sides, and head in the males are often charged with pig- 
ment, the prevailing color of which is rosy, though often satin- 
white, orange, crimson, yellow, greenish, or jet black. Among 
American genera Chrosomus, Notropis, and Rhinichthys are most 
highly colored. Rhodeus, Rutilis, and Zacco in the Old World 
are also often very brilliant. 
In very many species, especially in America, the male in 
the breeding season is often more or less covered with small, 
SN 
YIN 
) ) 
TAS 
Fig. 123.—Black-nosed Dace, Rhinichthys dulcis Girard. ‘\ellowstone River. 
grayish tubercles or pearly bodies, outgrowths of the epidermis. 
These are most numerous on the head and fall off after the 
breeding season. They are most developed in Campostoma. 
The Cyprinide are little valued as food-fishes. The carp, 
largely domesticated in small ponds for food, is coarse and 
