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<br />reintroduction does not occur, bonytail should be considered extirpated from the Upper <br />Basin. The bonytail reintroduction plan is an interactive guideline and process of <br />evaluation that outlines the reintroduction and eventual recovery of hatchery feared <br />bonytail into their native environment of the Green and Colorado rivers. Because so <br />little is known about life history requirements and evolutionary history of bonytail, <br />laboratory experiments will be conducted to help in the design of the reintroduction <br />stocking program. Reintroduction will be implemented through field experimentation <br />to determine ecological factors important to stocked fish and to different life stages of <br />bonytail. This plan is formatted to incorporate current and proposed experimentation <br />into the implementation and management of the bonytail reintroduction in the Upper <br />Basin. The plan is intentionally designed to adapt laboratory and field experimental <br />results into outyear objectives. <br /> <br />26 GILA TAXONOMY: ALLOZYME & MORPHOLOGY <br /> <br />The project was designed and conducted to clarifY the taxonomic status and <br />distribution of Gila fish species throughout the Colorado River basin and several <br />Mexican basins. Non-lethal tissue sampling methods were developed. The project <br />provides baseline information for future genetic monitoring of endangered fish <br />populations in the Colorado River system. This study will compare morphological data <br />and genetic analyses using protein electrophoresis that were obtained from over 1,200 <br />specimens from 61 populations. Additional correlated studies of non-recombinant <br />genetic data using mtDNA were planned in a separate scope of work for FY 95-96 <br />(Recovery Program Project #27). Morphology and alIozyme portions of the project <br />are summarized in a draft report. <br /> <br />Recommendations: It was strongly recommended that investigations of mitochondrial <br />DNA (mtDNA) be completed so that all morphological and genetic information can be <br />compared for the final analyses. The mtDNA work is being completed under a <br />Cooperative Agreement with Arizona State University with Dr. Thomas Dowling as <br />the principal investigator. The results of such non-recombinant studies, combined with <br />the results of this project, will be essential to understanding the nature and-underIying <br />processes of genetic variation in the.Gili! complex. The target date for completion of <br />the mtDNA work is scheduled for January, 1997. <br /> <br />27 GILA TAXONOMY: MTDNA <br /> <br />Several endemic Colorado River fishes of the genus Gila are listed as endangered under <br />the Endangered Species Act: bonytail (Qi,@ ele~ans) and humpback chub (Qi@ cypha). <br />The development and implementation of recovery programs have been complicated by <br />the taxonomic confusion that exists between the bonytail, humpback chub, and the <br />roundtail chub (.Gili! robusta). Many specimens of the Qi@ complex are intermediate in <br />gross morphology such that field identification of such specimens is uncertain. The <br />taxonomic and phylogenetic relationships within the genus Gila are being explored <br />through morphological and genetic studies. The morphometric analysis of <br />comprehensive collections of Gila from the entire Colorado River basin has been <br /> <br />A-23 <br />