Stomphia didemon is a sea anemone (family Actinostolidae) found in cold temperate and boreal waters of the North Pacific and North Atlantic, notable for its remarkable escape swimming behavior in response to contact with predatory sea stars—contracting its body and detaching from the substrate to drift away from the threat. This swimming escape response has made Stomphia a classical subject for studying cnidarian neuromuscular physiology and behavioral ecology. Genomic data have been generated for this species and are available in public databases, enabling comparative studies of cnidarian evolution and ecology.