| INTRODUCTION Mechanisms for regulating the specific weight of the body are well known in fishes. In other aquatic vertebrates the lungs might have a function similar to that of the swimbladder or the lungs in fishes. In anuran tadpoles the lungs may serve as hydrostatic balancers, but this has not been verified experimentally. Active regulation of lung volume, and thus of body volume and specific weight, during diving is unknown in adult anurans, although Parker (1936) expressed the opinion that in male Trichobatrachus robustus the lungs, which possess a posterior diverticulum surrounded by specialized musculature, serve as a hydrostatic apparatus. If there is no active regulation of lung volume during diving, the volume of the lungs will depend on such... |
