Abstract
Abstract: Supplemental breeding is an intensive population management strategy wherein adults are captured from nature and spawned in controlled settings, and the resulting offspring are later released into the wild. To be effective, supplemental breeding programs require crossing strategies that maximize offspring production while maintaining genetic diversity within each supplemental year class. We used computer simulations to assess the efficacy of different mating designs to jointly maximize offspring production and maintain high levels of genetic diversity (as measured by the effective population size) under a variety of biological conditions particularly relevant to species with high fecundity and external fertilization, such as many fishes. We investigated four basic supplemental breeding designs involving either monogamous pairings or complete factorial designs (in which every female is mated to every male and vice versa), each with or without the added stipulation that all breeders contribute equally to the total reproductive output. In general, complete factorial designs that did not equalize parental contributions came closest to the goal of maximizing offspring production while still maintaining relatively large effective population sizes. Next, we estimated the effective population size of 10 different supplemental year classes within the breeding program of the robust redhorse (Moxostoma robustum). Two year classes failed to produce progeny, whereas successful year classes used partial factorial designs to realize effective sizes ranging from 2 to 26 individuals. On average, a complete factorial design could increase the effective size of each robust redhorse supplemental year class by 19%.
Highlights
Many factors, including habitat degradation, overharvesting, exotic species introductions, and other anthropogenic influences, have severely reduced the range or population size of many species
Supplemental breeding is an intensive population management strategy wherein adults are captured from nature and spawned in controlled settings, and the resulting offspring are later released into the wild
Because complete factorial designs may not always be tractable in the field, we investigated the performance of partial factorial designs (e.g., Hedrick et al 2000)
Summary
Many factors, including habitat degradation, overharvesting, exotic species introductions, and other anthropogenic influences, have severely reduced the range or population size of many species. Thought to have been extirpated following European settlement, five living specimens of the robust redhorse were discovered in 1991 (Bryant et al 1996), and subsequent sampling efforts revealed extant populations in the Ocmulgee, Oconee, Pee Dee, and Savannah rivers. The Robust Redhorse Conservation Committee is implementing intensive management strategies to recover this species, reintroduce it to currently unoccupied rivers within its former range, and prevent it from formally being listed (Hendricks 1998). To help achieve these goals, a supplemental breeding program was established in 1993. The merits of supplemental breeding are debated (Snyder et al 1996, 1997; Hutchins et al 1997), this approach has become a common management technique for many fish species (e.g., Brown et al 2000; Hedrick et al 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
