• Effects of outbreeding on embryonic development timing of pink salmon (Oncorhynchus gorbuscha)

      Wang, Ivan Alan (2004-08)
      I studied the effects of outbreeding on embryonic development timing of pink salmon. I used standardized development stages and germ ring opening measurements to compare the variation of development at epiboly for odd- and even-broodyear F₂ hybrids. Analyses of timing of development at epiboly showed no effects of outbreeding depression, but did show a maternal effect for both crosses and backcrosses; and backcross families differed between replicates. These observations suggest that experimental designs lacking consideration of maternal effects or testing for replicate container effects in early salmon development studies may be flawed. I also compared the variation of hatching times for hybrids of two pink salmon populations, Pillar Creek (Kodiak, Alaska) and Auke Creek (Juneau, Alaska), which are separated by about 1,000 km. Analyses of hatching time showed that families with more Pillar Creek genes required more time to hatch at a given temperature. The differences in hatching time between the pink salmon from Auke and Pillar creeks demonstrates that they differed genetically. Both additive and epistatic types of outbreeding depression influenced the differences in hatching time. Prudent resource management requires knowledge of the biogeographical history and the genetic composition of salmon populations with the potential to interbreed.