Longfin Smelt

Longfin smelt (Spirinchus thaleichthys) are native to the West Coast, ranging from Alaska to California. This anadromous species is typically found in bays and estuaries before moving into coastal streams for spawning. Adult longfin smelt are typically olive brown on their dorsal side with silver-white lateral and ventral areas. During breeding, males may become moss-green on their dorsal side and develop black speckling on their head and back and tubercles on their paired fins. When inhabiting brackish water, adults and juveniles of this species feed on small crustaceans. Longfin smelt face threats from multiple sources including reduced outflows, introduced species, and habitat loss. The species was listed under the California Endangered Species Act as Threatened, and the San Francisco Bay-Delta population of longfin smelt warrants protection under the federal Endangered Species Act.

Fun Fact: Female longfin smelt can lay about 24,000 adhesive eggs that stick to substrates, rocks, and aquatic plants.