In a study published in the journal Molecular Ecology, SWFSC Fisheries Ecology Division scientists have used intergenerational genetic tagging of Russian River steelhead to demonstrate high heritability in the timing of their return from the ocean and subsequent reproduction.
This discovery means that when steelhead reproduce can be partially predicted by when their parents reproduced. This is the first time that a genetic component to reproductive timing has been demonstrated in steelhead, and one of the first times that it has been formally demonstrated in an anadromous fish.
This finding has implications for management and conservation of the species. It indicates that fish returning to one of the two hatcheries in the basin at the same time have an elevated chance of being siblings, and extreme inbreeding could occur if they were mated together. More generally, it indicates that actions that increase or decrease the ability of steelhead to reproduce during part of the season could change the future reproductive timing of the population, potentially creating mismatches between reproductive behavior and environmental conditions.
These results also demonstrate the extraordinary power of pedigree-based genetic tagging in salmonid fishes (a technique pioneered by Fisheries Ecology Division scientists John Carlos Garza and Eric Anderson) for providing biological inference that is not easily achievable with traditional physical tags.
Abadía-Cardoso, Alicia, Eric C. Anderson, Devon E. Pearse, and John Carlos Garza. 2013. Large-scale parentage analysis reveals reproductive patterns and heritibility of spawn timing in a hatchery population of steelhead (Oncorhynchus mykiss). Molecular Ecology 22(18):4733-4746. DOI: 10.1111/mec.12426
(View article on publisher's site -- subscription may be required.)
Contact: SWFSC Fisheries Ecology Division, Molecular Ecology and Genetic Analysis Team
(August 26, 2013)