title: Tongue adhesion in the horned frog Ceratophrys sp.
abstract: Frogs are well-known to capture elusive prey with their protrusible and adhesive tongues. However, the adhesive performance of frog tongues and the mechanism of the contact formation with the prey item remain unknown. Here we measured for the first time adhesive forces and tongue contact areas in living individuals of a horned frog (Ceratophrys sp.) against glass. We found that Ceratophrys sp. generates adhesive forces well beyond its own body weight. Surprisingly, we found that the tongues adhered stronger in feeding trials in which the coverage of the tongue contact area with mucus was relatively low. Thus, besides the presence of mucus, other features of the frog tongue (surface profile, material properties) are important to generate sufficient adhesive forces. Overall, the experimental data shows that frog tongues can be best compared to pressure sensitive adhesives (PSAs) that are of common technical use as adhesive tapes or labels.
authors.affiliation: Christian-Albrechts-Universität Kiel, Functional Morphology and Biomechanics, Am Botanischen Garten 1-9, 24118 Kiel, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kleinteich
authors.affiliation: Christian-Albrechts-Universität Kiel, Functional Morphology and Biomechanics, Am Botanischen Garten 1-9, 24118 Kiel, Germany.
authors.forename: Stanislav N
authors.initials: SN
authors.lastname: Gorb
mesh_terms: D000818:Animals; D001001:Anura / Q000502:physiology*; D001696:Biomechanical Phenomena; D008124:Locomotion / Q000502:physiology*; D008954:Models, Biological; D033081:Shear Strength; D013499:Surface Properties; D000267:Tissue Adhesions; D014059:Tongue / Q000502:physiology*