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What is a sympatric population of resident and anadromous O.mykiss?
Sympatry- “Occurring in the same area; specifically : occupying the same range without loss of identity from interbreeding”.
Prerequisites for a population of O.mykiss defined under sympatry:
- Overlap in spatial and temporal distribution between resident and anadromous ecotypes.
- Reproductive isolationism
- Occur during freshwater rearing lifestages
- Competition for food and space
- Spawning life stage
Notes:
How do we define a sympatric population of Omykiss? Webster defines sympatry as…… Sympatric populations can be defined in two separate ways, both requiring overlap in the spatial and temporal distribution. Under the first circumstances where you have reproductive isolationsism, interactions would occur in the freshwater rearing lifestages where juveniles compete for food and space. The second alternative requires overlap during the spawning lifestage. This induces the inbreeding potential for hybrid crosses where progeny derived from these crosses could phenotypically express either life history pathway. Overlap during the spawning lifestage would also imply the initial conditions of overlap at the rearing lifestages. In the Upper Yakima we have a significant amount of overlap in the spatial and temporal spawning distribution where biologists have observed resident males spawning with anadromous females.