Common name: Smelt Non-native. ID: Two dorsal fins, long thin body with purple, pink and blue shiny sides Life cycle: Spawn on gravel beginning in early spring for about 3 weeks, depending on the weather. Mature by the end of 2, maximum 3, seasons. Grow to an average size of 7-8 inches. Feed on: insects, insect larvae, other aquatic invertebrates, small smelt, sculpins, burbot, whitefish, small fish. shrimp-like crustaceans Predators: Coho salmon, burbot, trout, walleye, yellow perch and other smelt! How to catch one: Dip-net them in streams during spawning season, can be found in dark, cool waters due to light and temperature sensitivity. Can be used as bait for catching some of their larger predators.