Meeting Abstract

P1.106  Saturday, Jan. 4 15:30  A morphological analysis of the suction-disc performance and interspecific host association in the remoras (Percomorpha: Carangiformes: Echeneidae) STOTE, A*; KENALEY, CP; Harvard University; Harvard University astote@college.harvard.edu

The percomorph family Echeneidae consists of eight species of marine fishes that hitchhike by adhering to a host via a dorsal sucking disc. Osteological components of this unique suction device are composed of serially arranged, hierarchically organized substructures. While recent studies have focused on the evolution and development of the modified dorsal-fin osteology that forms the specialized disc, very little work has focused on the morphological basis of adhesion. Further, the range of disc performance appears to be very broad with some species that adhere to slow-swimming, rough-skin hosts (e.g., requiem sharks) and others that adhere to fast-swimming, smooth-skin species (e.g., rorqual whales). Thus, the relationship between disc design and functional performance remains unstudied. The goal of our study was to identify the anatomical properties of the echeneid disc system that influence adhesion performance and may be implicated in host association. The specific aims of the study were to (1) characterize the morphology of the disc system through micro-CT analysis of all eight species of the family Echeneidae and (2) identify axes of disc morphospace that covary with host surface roughness and locomotor speed. We found that variation in disc morphospace can be explained by only a few of the 18 morphological variables measured. Axes of morphospace defined by these variables have strong positive relationships with both host surface roughness and locomotor speed. The results of our work are discussed in the context of morphological properties that may constrain host specificity and inspire improvements to man-made, suction-based adhesion devices.