Elastic structures in the vocalization apparatus of the Túngara frog Physalaemus pustulosus (Leptodactylidae).
Histological analysis of the vocal sac and body wall in the leptodactylid frog Physalaemus pustulosus suggests that both muscle and elastic fibers are important in call production. Abdominal musculature as well as abdominal bands of elastin (the lineae masculinae) provide the energy required for exhalation and sound production. Air flowing through the larynx inflates a highly extensible vocal sac lined with muscle and a network of elastic fibers. Inherent elasticity together with muscular activity of the vocal sac likely increase the speed and possibly decrease the energetic costs of lung reinflation following vocalization. The mechanics of call production in P. pustulosus thus involve not only laryngeal activation but also elastic transfer of air between the supralaryngeal vocal sac and abdominal respiratory structures.