© Zoological Institute, St. Petersburg, 2008 Hybridization of the Atlantic salmon (Salmo salar L.) and brown trout (S. trutta L.) A.A. Makhrov Makhrov, A.A. 2008. Hybridization of the Atlantic salmon (Salmo salar L.) and brown trout (S. trutta L.). Zoosystematica Rossica, 17(2): 129-143. Hybrids between the Atlantic salmon and brown trout can be identifi ed on the basis of genes coding for several protein and DNA markers. Hybrids are found in all regions where the Atlantic salmon and brown trout are sympatric. The main causes of the hybridization are the sneaking of mature male parr, escape and release of cultivated fi shes, unstable river discharges, and overfi shing. In numerous experimental crosses, the survival of F1 hybrids varies from zero (a complete loss) to normal. Post-F1 hybridization sometimes results in gynogenesis, hybridogenesis and introgression. The role of hybridization in the evolution of Salmo is discussed. A.A. Makhrov, Vavilov Institute of General Genetics RAS, Gubkin str. 3, GSP-1, Moscow, 119991, Russia. e-mail:
[email protected] Introduction on natural and artifi cial hybridization between these species. Interspecifi c hybrids are interesting in terms of evolutionary genetics as well as conservation Methods of hybrid identifi cation genetics. Hybridization is an important factor of evolution: many animal species have originated Life history characters through distant hybridization (reviews: Sere- brovskiy, 1935; Dowling & Secor, 1997; Barton, “Typical” Atlantic salmon spawners are large 2001; Arnold & Burke, 2005; Mallet, 2007). anadromous fi sh. Anadromous brown trout (sea However, the environmental impact of human ac- trout) do not travel so far to the sea and may visit tivities may also promote hybridization (reviews: freshwaters without spawning.