STOP, CHOMP, AND ROLL: ROTATIONAL FEEDING BEHAVIOR IN MARINE SCULPINS

In summer 2022 at the University of Washington Friday Harbor Laboratories on San Juan Island, Washington, we recorded 4 species of marine sculpin, Oligocottus maculosus, Leptocottus armatus, Clinocottus globiceps, and Clinocottus embryum, performing rotational feeding behavior in which the fish rapidly rotates about the body axis in order to break off a manageable piece of a prey item. These recordings were made while filming prey-capture trials as part of another study. Although these behaviors have been observed in distantly related groups of primarily anguilliform fishes, these are the first filmed recordings of stout-bodied sculpin species performing rotational feeding behaviors consistently in a laboratory setting. The species observed in the study primarily prey upon small marine invertebrates and fish larvae that they bite or scrape off the substrate, or suction feed from the water column near the substrate. When offered large prey items, they are unable to obtain the food in their ordinary manner and instead bite off small pieces or perform the rotational behavior to assist in tearing off a manageable piece.