| Kokanee salmon | |
|---|---|
| |
| Schooling in a stream near Lake Tahoe, California. | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Salmoniformes |
| Family: | Salmonidae |
| Genus: | Oncorhynchus |
| Species: | O. nerka
|
| Binomial name | |
| Oncorhynchus nerka (Walbaum, 1792)
| |
| Synonyms[1] | |
| |
The kokanee salmon (Oncorhynchus nerka), also known as the kokanee trout, little redfish, silver trout, kikanning, Kennerly's salmon, Kennerly's trout, or Walla,[2] is the non-anadromous form of the sockeye salmon (meaning that they do not migrate to the sea, instead living out their entire lives in freshwater). There is some debate as to whether the kokanee and its sea-going relative are separate species; geographic isolation, failure to interbreed, and genetic distinction point toward a recent divergence in the history of the two groups. The divergence most likely occurred around 15,000 years ago when a large ice melt created a series of freshwater lakes and rivers across the northern part of North America. While some members of the salmon and trout family (salmonids) went out to sea (anadromous), others stayed behind in fresh water (non-anadromous).[3][4] The separation of the sockeye and the kokanee created a unique example of sympatric speciation that is relatively new in evolutionary terms. While they occupy the same areas and habitats during the breeding season, when ocean-going sockeye salmon return to freshwater to spawn, the two populations do not mate with each other in some regions, suggesting speciation.[5][6]
- ^ "Oncorhynchus nerka (Walbaum, 1792)". Global Biodiversity Information Facility. Retrieved 1 April 2023.
- ^ Wallis, Orthello L.; Bond, Carl E. (1950). "Establishment of kokanee in Crater Lake, Oregon". Journal of Wildlife Management. 14 (2): 190–193. doi:10.2307/3796331. JSTOR 3796331.
- ^ Cheng, Heng. "From Lakes to Oceans: Speciation of Sockeye Salmon and Other Fishes." Emory Scholars Blog. Emory University. April 30, 2014. Accessed February 14, 2018.
- ^ Lemay, Matthew A.; Russello, Michael A. (2015). "Genetic evidence for ecological divergence in kokanee salmon". Molecular Ecology. 24 (4): 798–811. doi:10.1111/mec.13066. PMID 25580953. S2CID 11274141.
- ^ Wood, Chris C.; Foote, Chris J. (1996). "Evidence for sympatric genetic divergence of anadromous and nonanadromous morphs of sockeye salmon (Oncorhynchus nerka)". Evolution. 50 (3): 1265–1279. doi:10.2307/2410667. JSTOR 2410667. PMID 28565300.
- ^ Yamamoto, S.; Kitamura, S.; Sakano, H.; Morita, K. (2011). "Genetic structure and diversity of Japanese kokanee Oncorhynchus nerka stocks as revealed by microsatellite and mitochondrial DNA markers". Journal of Fish Biology. 79 (5): 1340–1349. doi:10.1111/j.1095-8649.2011.03098.x. PMID 22026610.