Growth of Pylodictus olivaris (Rafinesque) in a Kansas Reservoir

Abstract

Spine sections were taken from pectoral spines secured from 200 flathead catfish collected from Milford Reservoir during 1975. Age determination was accomplished with the aid of a microprojector and comparison to spine sections taken from dorsal spines. The y-intercept of the body length-pectoral spine relationship was incorporated into a direct proportionality formula for back-calculating length at annulus formation. Length-weight relationships and condition factors were also computed for males, females, and the two sexes combined. Weights were back-calculated at annulus formation based on back-calculated lengths utilizing the length-weight relationship derived from empirical data. 1979. Age and growth studies of flathead catfish in Kansas have for the most part been restricted to riverine environments. Cross and Hastings (1956) reported concerning the ages of twenty-nine flathead catfish collected from the Kansas River. Minckley and Deacon (1959) determined growth rates of flathead catfish from the Big Blue River and the Neosho River. Other studies have been compiled on age and growth of flathead catfish collected in Oklahoma waters (McCoy, 1953; Jenkins, 1952). In most of these studies, a direct proportion was assumed in the body length-pectoral spine relationship. The y-intercept was assumed in most cases to be zero. A secondary purpose of this study was to document age and growth of flathead catfish in a large Kansas Reservoir. A food habit study was also completed in relationship to age and growth and is to be the topic of another publication. All specimens utilized for this study were collected from Milford Reservoir above the town of Milford, Kansas. Milford Reservoir was constructed by the U.S. Army Corps of Engineers as a flood control impoundment and water was first impounded in 1967. The dam is located four miles northwest of Junction City, Kansas, on the Republican River. Milford Reservoir, at conservation level, has a surface area This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:40:10 UTC All use subject to http://about.jstor.org/terms