32 UNIVERSITY OF COLORADO STUDIES 



authors the suckers, Catostomidae, are included in the Cyprinidae as one of these 

 groups. Considering the extremes, two types of Cyprinids may be recognized 

 as regards the alimentary canal and the food taken. These are the herbivorous 

 forms with long, much-coiled alimentary canal, the more primitive forms on the 

 whole, and the carnivorous forms with a relatively short alimentary canal. B etween 

 these are other intermediate forms, and both herbivorous and carnivorous types 

 are usually represented in each large group of species. 



The economic importance of the Cyprinidae does not come from their value 

 to man directly, for few species are extensively marketed or sought as game fishes, 

 but from their value as food for other game and food fishes. A few species, as the 

 Goldfish and the Tench, are raised as aquarium fish and for small ponds and lakes 

 in parks. 



The large number of species, their general similarity and small size conspire 

 to make the identification of Cyprinids difiicult. The introduced species may be 

 recognized by the long dorsal and the serrate anal and dorsal spines, but the native 

 species are more confusing. In using the keys for this family one of the most 

 elusive structures to be looked for is the barbel. In some species, as the German 

 Carp, the barbel is quite prominent, but in most of the native species it is quite 

 small. The barbel when present is on the ventral surface of the head at the 

 junction of the upper and lower jaws, usually in a small depression or, in SemotUus 

 and Couesius, just above the junction of the jaws on the outside margin of the 

 upper. In most of the Cyprinids found in Colorado having a barbel, the barbel 

 is less than one-sixteenth of an inch in length although in large specimens of 

 SemotUus alromaculatus it may be almost a quarter of an inch long. The char- 

 acters based on internal anatomy given in the keys are not necessary for the 

 determinations but may be used to confirm them.' 



Key to Genera of Family Cyprinidae in Colorado 

 a. Dorsal fin elongate, of more than 20 rays; both dorsal and anal fins preceded by a serrate 

 spine. Introduced species natives of Asia. 

 b. Barbels 4; body completely scaled, partly scaled or naked 



Cyprinus (Artedi) Linnaeus, p. 34 

 bb. Barbels wanting; body completely scaled; color often orange-red. Carassius Nilsson, p. 36 

 aa. Dorsal fin short, of 10 or fewer rays; fins without a serrate spine. Native species. 

 C. Body scaled; dorsal fin without a spine. 



d. Intestine long, wound around the air bladder; mouth ventral and sucker-like; pre- 

 maxillaries protractile; no maxillary barbel; color dusky, irregularly mottled, sides 



with a more or less brassy luster Campostoma Agassiz, p. 36 



dd. Intestine not wound around the air bladder. 



e. No maxillary barbel; premaxillaries usually protractile. 



f. Two very distinct dark lateral bands; scales small, usually about 80 in the 

 lateral line, imbedded in the skin; species small, length under 70 mm.; intestine 

 about twice the length of the body. . . . Chrosomus Rafinesque, p. 38 



' The common tench, Tinea tinea, was introduced into Colorado in 1894 (see Kept. U.S. Fish Com. for 

 1894-95, p. S3), but there are no reports of this species from Colorado waters. This fish may be recognized 

 by the long dorsal fin of 10 rays and by the small scales, more than 60 in lateral line. 



