In aquatic vertebrates such as the cyclostomes, fishes, and urodele Amphibia, the digestive tract develops as a relatively straight tube characteristicalaly bent toward the right side in the region of the pylorus and duodenum. Aiiuran amphibians excite particular interest because they are the most primitive vertebrate group to deve1,op a highly coiled intestine, such as amniotes generally posse...

Temporal computations are important in the acoustic communication of anurans. In many cases, calls between closely related species are nearly identical spectrally but differ markedly in temporal structure. Depending on the species, calls can differ in pulse duration, shape and/or rate (i.e., amplitude modulation), direction and rate of frequency modulation, and overall call duration. Also, beha...