Brown trout (Salmo trutta) can reach a weight of about 45lb and a length of 45 inches. Their average size is between 1 and 5lb and 10 and 20 inches.
While rainbow trouts are true trouts, lake trouts are actually char. Lakers have dark bodies with light spots, while rainbow trout have light bodies with dark Spots. Rainbow trout have a broad, reddish stripe along their lateral line, which lake trouts lack entirely.