Meeting Abstract
Remoras comprise a family of fishes (Echineidae) unique in their cranial adhesive disc evolved from dorsal fin spines. Analysis of the adhesive mechanism by which remoras attach to hosts of varied roughness has focused primarily on the functional morphology of skeletal structures; little attention has been paid to the soft tissues of the disc and their role in attachment. Here, we use scanning electron microscopy (SEM), histology, and material testing to describe the functional morphology of the soft tissues of the remora adhesive disc and generate hypotheses on their roles in the adhesive mechanism. Using SEM we identified previously undescribed papillary structures on the fleshy lip surrounding the disc and found epithelial tearing on the lamellae suggestive of spinule replacement and growth Histological examination revealed complex arrangements of collagen fibers with more dense and organized collagen bundles found anteriorly. Moreover, collagen bundles at the anterior lip were oriented in a cross-hatching pattern, suggesting a functional regionalization between the anterior and posterior sections of the lip. Histology did not show any mucus or mucus secreting cells; however, it did reveal large nerves extending down the distal edges of the lips and at times reaching the individual papilla, indicative of a role in modulating attachment forces.
