The Rainbow Trout (Oncorhynchus mykiss) is a colorful and popular sport fish, native to cold-water tributaries of the Pacific Ocean in Asia and North America. They can grow up to 30 inc... The Rainbow Trout (Oncorhynchus mykiss) is a colorful and popular sport fish, native to cold-water tributaries of the Pacific Ocean in Asia and North America. They can grow up to 30 inches in length and are known for their vibrant coloration, with a pinkish stripe running along their sides and black spots across their body. Rainbow Trout are opportunistic feeders, eating insects, crustaceans, and smaller fish. They are widely stocked in freshwater bodies for angling and conservation purposes.Click here to read more about Rainbow Trout.