Family CYPRINIDAE 



THE MINNOW FAMILY 



Tlie ininnovvs are usually fishes of small size, though the carp, which 

 is not native, may reach a weight well over 50 pounds. Several Ameri- 

 can species reach a weight of several pounds and a length of 18 inches, 

 but many species seldom reach a length of over 2 inches. Over 2000 

 species are known. Jordan, Evermann, and Clark (1930) list 307 species 

 for North and Central America. With the exception of one Japanese 

 species, all minnows are strictly fresh-water fishes. 



The minnow family is represented by more individuals and species 

 than any other family of fishes in Minnesota and neighboring states. 

 Hubbs and Cooper (1936), describing the minnows of Michigan, state 

 that the number of minnows in Michigan waters probably runs into 

 many hundred millions. They attribute this abundance to at least 

 three factors: Minnows as a group occupy a great variety of habitats 

 and eat many types of foods; most species of minnows require a rela- 

 tively short time to reach sexual maturity; a large number of minnows 

 can occupy a small space and find suflficient food and shelter because 

 they are usually small fishes. 



Externally many species are so similar that it is difficult to distinguish 

 them from one another. Consequently this family is extremely difficult 

 to study. In addition the name "minnow" is often applied locallj^ with- 

 out discrimination to any small fish, and also there are a number of 

 small fishes called minnows, such as the topminnow and mudminnow, 

 which belong to other families. 



In the spring the males often develop tubercles on the top of the head 

 and sometimes on other parts of the bod3^ In some species bright colors, 

 particularly red, orange, and yellow, appear on the fins and in streaks 

 along the body. Young individuals are usually more slender than the 

 adults of the same species, and the eye is always much larger. The young 

 fishes often show a black lateral stripe and caudal spot not possessed by 

 the adults, though these marks are also common in the adults of many 

 species. 



All members of this family have the head naked in the nonbreeding 

 state. One dorsal fin is present, and the spines are absent in all local 

 species except the introduced carp and goldfish. Less than 10 soft 

 dorsal rays are present in native minnows, but this number is exceeded 

 in the introduced carp and goldfish. No teeth are present on the jaws. 

 Pharyngeal teeth are well developed and form one of the most im- 

 portant characters for identification. The teeth are arranged in not 

 more than two rows on each posterior branchial arch in all local species 

 except the carp, which has three rows. The outer row contains 1 or 2 



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