Osmeroidea

The Osmeroidea are a superfamily of ray-finned fishes that includes smelts and icefishes. These fish are closely related to salmon and trout and are found in cold northern waters. Smelts, like trout, possess a small, fleshy adipose fin. They are slender carnivores that typically spawn in freshwater environments, often migrating upstream for this purpose.12

The American smelt (Osmerus mordax) is a notable species that has been introduced to the Great Lakes and supports a commercial fishery. Other related Pacific species include the rainbow herring, surf smelt, capelin, and the eulachon, or candlefish, which is so oily it can be burned as a candle when dried. Osmeriform fishes, including those in the Osmeroidea superfamily, are found in marine, anadromous, and freshwater habitats across the Northern Hemisphere, with some ecologically similar species also present in the Southern Hemisphere.213