Laserfiche WebLink
<br /> <br /> <br />'157~"":::': -':'-:' ' <br /> <br />156 <br /> <br />CALIFORNIA FISH A~L> GAME <br /> <br />THE FISHERY OF THE LOWER COLORADO RIVER- <br /> <br />preference, it has not kept it from inhabiting some of the muddiest sec. <br />tions of the Colorado drainage. It has been taken from the Grand <br />Canyon where the silt load is still extremely great, and from the .Alamo <br />and New rivers which run chocolate-brown.2o, The collections made in <br />1942 would lead one to believe that it has shOwn a greater degree of suc- <br />cess in all types of Colorado River water than has any of the other game <br />fishes. <br /> <br />Size. In the Colorado it reaches a large size which is comparable in <br />every way to that usually attained in its native waters, Forbes and Rich. <br />ardson (1920) say that in Illinois" It is seldom taken of more than fiw <br />pounds weight, aIthougnspecimensal'e occasionally seen weighing from <br />fifteen to twenty pounds." Similar statements are given by other <br />authors. <br /> <br />~.aphs which have been seen make it certain that quite a number <br />," nl:l catfish weighing 10 to 15 pounds or over have been taken in <br />rs,-the fish which are usnally caught are muchsmaHer. During, <br />~ survey many large catches composed entirely of fish from about <br />,}~ches in length were seen. <br /> <br />(f,uCtion, The smallest fish seen which could definitely be said to <br />ally mature (adults) were two females 7.3 inches in length taken <br />ions Dam on April 14, 1932, by E, H. Glidden. In 1942 eight <br />:e females were seen which would have spawned in that year. These <br />in size from 8,3 to 26 inches in length. Fourteen other females <br />g from 1.3 to 15.0 inches in length were examined which may have <br />~-irfiS1i:-' 'The largest female seen which it was believed was a sexll,- <br />ature (young) fish was 10,4 inches long. - . <br />,'e segregation of the fish examined into three classes (young or' <br />fiire, ripening or ripe adults, spent adults) was not based on very <br />i~r.n~ria. Those classed as ripening adults were easy to distin- <br />\:llrossexamination of their ovaries showed them to be turgid and to <br />~large trl1nslucent eggs. Fish whose ovaries lacked these eggs could <br />~', ejther immature or fish which had spawned. No exact line <br /><be drawn between these two classes in the material available. Flac- <br />\r.the ovaries and the size of some of the fish examined made it <br />atsome of those lacking the large eggs might have spawned. <br />...::tbe collections were not large enough to settle this question <br />, , roy, one can not offer an opinion as to the upper size limit at <br />~uspecies usually becomes sexually mature in the Colorado. It <br />yoe said that some females spawn at the small size of 7,3 inches; <br />'. in&. size of at least 10,4 inches may possibly be reached befor~ <br />.is attained. <br />eonly fish seen which appeared to be almost ripe (i.e" haTIng large <br />". Qst free from the ovarian walls) were two females, 12.0 and 16.6 <br />in length, taken on April 26, 1942, at Laguna Dam. A fish in <br />well-developed eggs were apparent was taken as early as January <br />,!2.at Yuma. The ripening eggs from this fish (26 inches long and <br />riTln;i'ID weight) had an average diameter of 2,5 m,m. (about one- <br />,]ncnJ,but were still undetached, Another fish ( 8,9 inches) with <br />,~.ed eggs of the same size was taken at Parker just four months later <br />:TJ9, 1942) .21 'Mature but unspawned females were also seen at Lake <br />~on May 21, 1942. The earliest date at which fish presumed to be <br />":-w:ere seen was April 26th. <br />neo--ril such meager data it can only be assumed that the spawning <br />,'inthe Colorado oceurs during the spring and summer. This agrees <br />.obsj:!rvations made in other regions. (See Adams and Hankinson, <br />;r":-."'" <br />~Bumber of mature (translucent) eggs produced was calculated <br />-~~specimens.22 A fish 8.5 inches long taken on February 7, 1942, <br />ed:approximately 1,600 eggs; another, 26 inches long, taken on <br />)9, 1942, contained approximately 34,500 eggs, <br /> <br />FIG, 68, Catfish fishermen at th" heau of the Alamo Canal. Jan, 1942, <br /> <br />There is a photograph at Needles Boat Landing of a catfish eanght <br />in Lake Havasu in 1941 and reported to weigh 22 lbs, 9 oz. Sinet' 19W <br />the Yuma Valley Rod and Gun Club has held a "prize fish contest" dur' <br />illg the February-April period of each year, The weights of the large~t <br />channel catfish entered in these contests are as follows: 1940, 19 Ibs, 1~ <br />oz, ; 1941, 14 lbs. 8 oz.; 1942, 20 Ibs, 8 oz,; 1943, 16 lbs, 12 oz. (_-\.11 fish <br />are weighed on accurate scales.) Of course, as for all fish, there are <br />reports of some phenomenal catfish in the Colorado which-had they <br />\reen caught-would have far exceeded these weights. While the report' <br />of local game wardens, the accurate records of the Yuma Club and other <br /> <br />,., Several specimens taken from the Grand Canyon in 1937 have been eX3~lin<'; <br />by the author in the collection of the United States :-;"ational Park Service at 'Jf"llu <br />Can;-on Village, <br /> <br />n" egg sizes based on the measurement of 200 eggs from each fish atter preser- <br />: :1>% formalin for several months. Shira (1917) gives the size of channel <br />:~ as :\.I;S m,m. when extruded. <br />Samples of known percentage (by weight) were taken from three parts of the <br />:.'the eggs counted. <br /> <br /> <br />I <br />i <br />I <br />! <br />,t <br /> <br />~ " <br />