Genetic Aanalysis of Size in an Anadromous Population of Pink Salmon

Abstract

Variation of size, particularly among males, has a significant genetic basis in pink salmon (Oncorhynchus gorbuscha) in Auke Creek, southeast Alaska. Heritability (h2), based on variance components of 118 full sib − 59 paternal half sib families of mature fish tagged as fry with coded micro wires, are higher in males (h2 length: 0.8 ± 0.3 (mean ± SE); h2 weight: 0.6 ± 0.2, based on sire effect) than in females (h2 length: 0.3 ± 0.2; h2 weight: 0.4 ± 0.2). Realized heritability probably would be smaller because of environment variability between brood years in factors affecting size and growth. Estimates based on regression of offspring means on fathers' values are smaller (h2 length: 0.4 ± 0.1 in males; 0.2 ± 0.1 in females; h2 weight: 0.0 in males and 0.1 ± 0.1 in females). Estimates of genetic, environmental, and phenotypic correlations of length and weight are all >0.7 (SEs <0.1). Estimates of genetic correlation between length and day of migration from the sea are near 0.4 ± 0.2; estimates of environmental and phenotypic correlations between these traits are smaller (<0.2, SEs <0.1).

Evolutionary consequences of fishing and their implications for salmon

“…More recent studies that have focused on the genetic architecture of salmonid life history include analyses of growth, size and maturation (e.g. Smoker et al. 1994; Quinn et al.…”

Morphological divergence rate tests for natural selection: uncertainty of parameter estimation and robustness of results

“…As it depends on the environmental component of variance, the heritability of a character is also a variable parameter among populations in different environments and within populations at different times (Falconer and McKay, 1996). In the literature, the heritability estimates for morphological characters of fish species vary from 0.14 to 0.80, where even the lowest values are statistically significant (Smoker et al, 1994;Taniguchi et al, 1996;Jonasson and Gjedrem, 1997;Choe and Yomozaki, 1998;Nakajima and Taniguchi, 2002). Within Poeciliids, Mousseau and Roff (1987) reported a median heritability of 0.745 for morphological characters in the mosquitofish (Gambusia affinis).…”

Current conservation genetics: building an ecological approach to the synthesis of molecular and quantitative genetic methods

“…Adult return rates in anadromous populations are often so low that many thousands of juveniles must be reared to provide a sufficient sample of adults. It is telling that only a single study provides heritability estimates for salmon in the wild (Smoker et al. 1994).…”

“…In many cases, it is only through quantitative genetic breeding studies that the genetic architecture of complex traits can be learned. Important insight has been gained in common garden experiments in salmonids demonstrating the persistence of phenotypic differences between populations reared in the same environment (Smoker et al. 1994; Palm & Ryman 1999).…”