Meeting Abstract

S5-8   14:00 - 14:30  Evolution of opercular jetting facilitates sediment fluidization in burying flatfishes Farina, SC*; Amacker, KY; Simmons, M; Elcock, JN; Rollins, M; Gibb, AC; Evans, KM; Howard University, Washington, DC; Howard University, Washington, DC; Columbia University, New York City, NY; Woods Hole Oceanographic Institute, Woods Hole, MA; University of California at Davis, Davis, CA; Northern Arizona University, Flagstaff, AZ; Rice University, Houston, TX stacy.farina@howard.edu http://stacyfarina.com

Granular sediment provides opportunities for benthic fishes to conceal themselves through burial, if they can overcome the enormous challenge of transitioning through the abiotic interface of water and substrate. Burying fishes are known to accomplish this by fluidizing sediment using a combination of body and fin movements. However, flatfishes (Pleuronectiformes) have additionally co-opted their ventilatory system to inject jets of water into sediment to enhance fluidization. This is surprising, because flatfishes lie on their sides, with only one gill opening facing the substrate, potentially reducing their capacity for opercular jetting. In this study, we present the evolutionary history of a unique adaptation to overcome this challenge - an actively controlled anatomical shunt that facilitates the movement of water between the symmetrical gill chambers. We examine the numerous evolutionary changes in skeletal morphology, muscular actuation, and ventilatory behavior that were necessary to establish this novel opercular jetting technique. We show that ventilatory jetting is relatively conserved among flatfishes, while shunt morphology varies greatly. We conclude that this complex anatomical and functional system has likely played a role in the success of this speciose clade.