If the farmed salmonid is native, it can interbreed with the wild native salmonids. A number of the parasitic Myxozoans are commercially important pathogens in salmonid aquaculture. The most commonly commercially farmed salmonid is the Atlantic salmon. Aeromonas salmonicida is a pathogenic bacterium that severely impacts salmonid populations and other species. Currently, much controversy exists about the ecological and health impacts of intensive salmonid aquaculture. The body of the chum salmon is deeper than most salmonid species. The rainbow trout has been reported to hybridize with at least two other salmonid species. Methods of salmonid aquaculture originated in late 18th-century fertilization trials in Europe. The area is a salmonid region, inhabited by the riverine brown trout. Cleaner fish are commercially cultured and introduced into salmonid sea cages. Again, climate change is also dwindling native salmonid populations. Cercariae penetrate less deeply in non-salmonid fish than in salmonid fish. As with other salmonid genera, the delimitation of species in "Salvelinus" is controversial. This ended natural salmonid migration on the river. Oysters and salmonid aquiculture is also increasingly important economically.