title: Establishing a captive broodstock for the endangered bonytail chub (Gila elegans).
abstract: It is crucial for endangered species to retain as much genetic variation as possible to enhance recovery. Bonytail chub (Gila elegans) is one the most imperiled freshwater fish species, persisting as a declining population of large and old individuals primarily in Lake Mohave on the lower Colorado River. Establishment of a new captive broodstock from the 1981 F1 progeny of at most 10 wild fish plus any newly captured wild fish is evaluated and reviewed. The effective number of founders contributing to the 1981 F1 progeny appears quite small, varying from approximately 3.5, based on F1 allozyme data and supported by mtDNA data, to approximately 8.5, based on the original production records. Using a sample of these progeny to initiate a new broodstock further reduces the effective number of founders. With even the most optimistic evaluation of the amount of genetic variation in F1 progeny, it is obvious that including wild fish in the broodstock is essential to increase the amount of genetic variation. The approach given here could be applied to retain genetic variation in other endangered species in a captive broodstock until they have stable natural populations of adequate size.
authors.affiliation: Department of Biology, Arizona State University, Tempe 85287-1501, USA. philip.hedrick@asu.edu
authors.forename: P W
authors.initials: PW
authors.lastname: Hedrick
authors.forename: T E
authors.initials: TE
authors.lastname: Dowling
authors.forename: W L
authors.initials: WL
authors.lastname: Minckley
authors.forename: C A
authors.initials: CA
authors.lastname: Tibbets
authors.forename: B D
authors.initials: BD
authors.lastname: Demarais
authors.forename: P C
authors.initials: PC
authors.lastname: Marsh
mesh_terms: D000818:Animals; D001947:Breeding; D003530:Cyprinidae / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000032:analysis; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D006239:Haplotypes; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D018807:Polymorphism, Single-Stranded Conformational; D015206:Southwestern United States
chemical_list: D004272:DNA, Mitochondrial; D007527:Isoenzymes