Three species of Pacific salmon have been introduced to Lake Superior in the past few decades. All feed in the big lake until they reach sexual maturity. Then, in the fall, they swim up rivers to spawn and then, inevitably, die. The largest, which has fared the best in its new environment, is the chinook salmon (also called king salmon). This fish grows to over 30 pounds, though most catches are around 10 to 15 pounds. Coho salmon, also called silver salmon, are smaller, averaging only about 3 to 4 pounds. The smallest salmon is the pink, or humpy (referring to the large hump on the back that males develop during breeding season). These latter two species are much less common in Minnesota waters of Lake Superior than the chinook.