China, for domestic consumption, recently decided to reclassify rainbow trout and related species as salmon. Once filleted and placed on a plate the two look very similar, but are completely different fish.
Salmon are born in fresh water but then live a good majority of their lives in the ocean. Salmon only return to fresh water to breed and then die. Rainbow trout live their whole lives in fresh water. These two are completely different fish.
There is a lot of fraud in China. The articles hint that much of what is sold in China as salmon has for years been rainbow trout, grown in aquaculture farms in Qinghai Province, far, far from the ocean. This fraud cheats Chinese people.