It is difficult to determine the sex of Atlantic salmon (Salmo salar) before it has reached sexual maturity. The natural ratio is approximately 50/50.
Roe production is particularly concerned with roe fish. A spawner produces 10 to 15,000 roe, and a milter is able to fertilise roe from several females. Farming milters into adulthood is regarded as expensive and waste of space, since it may be utilised more effectively for roe fish farming.
Researchers have identified a dna sequence, which makes possible to determine the difference between spawners and milters from very young age. When identified, the spawners are positively selected by using RealTime-PCR.
Contact person: Margreta Dam