SYSTEMATIC CATALOGUE OF FISHES. 137 



body is covered with small scales; the mouth is large, and in the adult male the 

 jaws are more or less hooked; teeth grow on the jaws, tongue, vomer, and pala- 

 tines; the vomer is flat; the fins are small, and the dorsal and anal contain only 10 

 to 12 rays. The general color is usually glistening silvery, and the markings are 

 black; the young ("parrs") are dark barred. {Salmo, salmon.) 



116. SALMO IRIDEUS Gibbons. 

 Rainbow Trout; California Trout. 



Salmo irideus Gibbons, Proceedings California Academy of Sciences, 1865, 36; Alameda county, California 

 Jordan &. Evermann, 1896, 500, pi. Ixxxi, fig. 216. 



Diagnosis. — Body relatively short, the form more elongate in male, depth contained 3.5 

 to 3.75 in length; head short, about .25 length; snout rounded, .33 lengtli of head; eye rather 

 large, .2 head; mouth comparatively small, the maxillary longer in male, in which it extends 

 beyond eye; vomerine teeth in 2 irregular series; scales in lengthwise series about 135, in cross- 

 wise series about 40; dorsal rays 10 to 12; anal rays 10 or 11; caudal fin concave or slightly 

 forked. Color: variable; sea-run fish brilliant silvery with few markings; adult fresh-water 

 examples dark bluish above, silvery on sides and below, a broad iridescent, red lateral band; 

 back, sides, and top of head, together with vertical fins, profusely marked with small, round 

 blackish .spots, {irideus, like a rainbow.) 



The waters of the Coast Range and Sierra Nevada mountains in California, 

 Oregon, and Washington are inhabited by a numerous group of trouts collectively 

 known as the rainbow trouts, which have become more or less differentiated 

 and are probably to be regarded as distinct species. They are among the most 

 beautiful, gamy, and deliciously-flavored of all trouts, and exhibit a wide varia- 

 tion in size, some in circumscribed waters never exceeding half a pound in 

 weight, while others normally weigh from 5 to 12 pounds. The fish has long 

 been cultivated, and has been planted by the general government in all suitable 

 waters of the United States. The form most extensively cultivated is indigen- 

 ous to the McCloud River and other streams south of Mount Shasta, and is 

 called Salmo irideus shasta. 



The rainbow trout has been introduced into various streams of North 

 Carolina, and is now firmly established. As early as 1880, the planting of 

 young fish in cold streams in the western counties was begun, and has been con- 

 tinued to the present time. This fish is adapted to warmer and more sluggish 

 waters than the brook trout, and is in no sense a rival of the latter. Waters that 

 have come unsuitable for brook trout through changed physical conditions may 

 be advantageously stocked with the rainbow trout. This fish feeds by prefer- 

 ence on insects, insect larvae, worms, and crustaceans, and preys on minnows and 

 other fishes only when its normal food is absent or insufficient in quantity. 

 While inhabiting some of the waters in which the brook trout occurs, the rainbow 

 is for the most part found lower in the streams. 



Among the state waters which have been successfully stocked with rainbow 

 trout are the lakes and streams of the Toxaway Company in Transylvania 

 County, where excellent fishing is now enjoyed by many persons each year. 



