Comparative and functional analysis of the digital mucus glands and secretions of tree frogs

摘要: Mucus and mucus glands are important features of the amphibian cutis. In tree frogs, their secretions crucial components adhesive digital pads these animals. Despite a variety hypothesised functions in frog attachment, functional morphology chemistry barely known. Here, we use an interdisciplinary comparative approach to analyse components, discuss roles attachment. Using synchrotron micro-computer-tomography, discovered arboreal Hyla cinerea that ventral differ from regular anuran form subdermal gland cluster. We show presence this cluster also several other—not exclusively arboreal—anuran families. cryo-histochemistry as well infrared sum frequency generation spectroscopy on two (H. Osteopilus septentrionalis) terrestrial, non-climbing species (Pyxicephalus adspersus Ceratophrys cranwelli), find neutral acidic polysaccharides, indications for proteinaceous lipid-like components. The varies only little between dorsal H. cinerea, abdominal O. septentrionalis, all four studied species. various families, absence differences non-arboreal indicate adaptation towards generic requirements attachment-related requirements. Overall, study contributes understanding role attachment bioadhesion general, evolution anurans.