The Biology of the Utah Chub, \u3cem\u3eGila atraria\u3c/em\u3e (Girard), of Scofield Reservoir, Utah

The Utah chub is one of the most important non-game fish in Utah. It has a wide range, and occurs in every drainage in Utah. The Utah chub is not important economically as food fish nor is it of much value commercially. The sportsmen think of this species as trash and do not consider catching or consuming them. However, the Utah chub may be caught on hook and line more readily than many game species. The Utah chub in Scofield Reservoir have been caught by trolling, bait fishing and fly casting and furnish considerable sport when caught with a light tackle. Their real importance becomes evident when a large population of Utah chub exist in waters where game fish species are desired. With their high reproductive potential, the Utah chub may become the dominant species and cause trout populations to decrease. This competition for food and space has been evident in many areas. Hazzard (1935) stated that Utah chub and trout compete with trout for food in Fish Lake, Utah, and Sigler (1948) also found that Utah chub compete with trout for food. This project originated June 1, 1957, when the Utah Fish and Game Department became concerned with the increased numbers of Utah chub in Scofield Reservoir. At this time it was evident that the Utah chub and other trash fish were the dominant species present. The project terminated September 25, 1958, when the lake was chemically treated for the control of trash fish, thus eliminating all fish populations within the reservoir and tributaries. Since competition between species is important, it is imperative that more information be obtained about the complete life history of the Utah chub, especially that period during the lifetime when they would be subject to economical control measures. Therefore, this project becomes threefold: (1) to establish the yearly rate of growth, (2) determine the types of food used by this chub population, and (3) collect data on spawning potential and spawning success