52 



BULLETIN OF THE BUREAU OF FISHERIES. 



dorsal fin from the opercle to the base of the caudal. The borders are interrupted here and there by 

 brassy or silvery scales. Above the black stripe are numerous reddish-bronze scales with dark spots. 

 The middle of the back is dusky, and this dark surface, together with the black stripe below, causes 

 the red area to stand out boldly, especially when the fish turning in the water flashes the metallic red 

 in the sunshine. Below the black stripe the body is silvery, many scales having a brassy sheen. 

 The ventral surface is clean, dead white. The upper part of the head is blackish, the lower part 

 whitish. The fins are slate blue, the paired ones lighter than the others. The tubercles are yellowish 

 white. When the fishes are observed in the water from directly overhead, the stripes are very 

 prominent, converging posteriorly and meeting over the caudal peduncle. The head appears lighter 

 than the body, and the fins are very distinct. Some individuals are much duller, but in every speci- 

 men there is at least a strong trace of the red and dark stripes. 



In the female the whole upper surface is dark brownish-black, not the olive color usually seen 

 in suckers. The sides are brassy, often more or less dull, and frequently the darker color is broken 

 up into clouds on the sides. Occasionally the entire dorsal region of a female is tinged with a reddish 

 coppery hue, the edges of the scales having a decided metallic luster. Sometimes the females are 

 called black suckers. At times whole schools of both sexes were seen, apparently ready to spawn, 

 but without a single individual with fully developed colors. 



Some Indians assert that they can distinguish between "cui-ui" from the different lakes. Those 

 from Winnemucca, said to be lighter in color and inclined to be spotted, are known as Izhi-"cui-ui." 

 The writer after examining many specimens from both lakes was unable to detect any difference. 



Observers differ somewhat as to the most distant point reached by C cujus during the nuptial 

 migration. It appears in large numbers at the great bend of the Truckee, and it certainly ascends 

 the river somewhat beyond the confines of the ancient Lake Lahontan. It never quite approaches 

 the swift water above Reno. It would no doubt be a physical impossibility for the species to stem 

 the turbxUent water of the river canyon. The great blunt head and huge body, loaded down with 

 eggs and fat, and the relatively small and weak caudal fin are not calculated to lend speed or endiuance 

 to a fish entering the current of a river for perhaps the first time. If Pyramid and Winnemucca Lakes 

 contract and become too salty for fresh- water species, as may possibly transpire if much water is with- 

 drawn from the Truckee River for irrigation purposes, this species no doubt will disappear. 



Spawning appears to be more active at night than in the daytime, and so, also, is migration. This 

 became evident from direct observation and from the fact that early morning usually revealed greatly 

 changed conditions in the river population. 



At times "cui-ui " appeared in such large and densely packed schools that considerable numbers 

 were crowded out of the water in shallow places, especially on the gently sloping river bars. Once 

 several hundred were observed stranded near the mouth of the river. In some places they were 

 jammed together in masses two or three deep. Some were crowded endrely out and dead, while 

 others were in water a foot deep, yet pushing close to the main group in a perfectly demoralized con- 

 dition. When one such conditionally free individual was carried some distance away and headed 

 upstream, it passed on its way with great speed, but if removed a short distance only it retiuned to 

 the mass like an iron to the magnet. It was impossible to separate any number and get them started 

 away from the stranded school. Cormorants, gulls, and pelicans in great numbers were attacking 

 them, and many of the still wriggling fishes had lost their eyes and strips of flesh had been torn from 

 their sides. 



The stomachs of all specimens examined were devoid of food. 



The largest specimen seen measined 670 millimeters, the smallest 410. 



