A fully distended vocal sac in an Australian red-eyed tree frog (Litoria chloris)Italian tree frog (Hyla intermedia) with an inflated vocal sacMarsh frog without inflated vocal sacMarsh frog with partially inflated vocal sacMarsh frog with inflated vocal sac
The vocal sac is the flexible membrane of skin possessed by most male frogs and toads. The purpose of the vocal sac is usually as an amplification of their mating or advertisement call. The presence or development of the vocal sac is one way of externally determining the sex of a frog or toad in many species; taking frogs as an example;
The vocal sac is open to the mouth cavity of the frog, with two slits on either side of the tongue. To call, the frog inflates its lungs and shuts its nose and mouth.[clarification needed] Air is then expelled from the lungs, through the larynx, and into the vocal sac. The vibrations of the larynx emits a sound, which resonates on the elastic membrane of the vocal sac.[1] The resonance causes the sound to be amplified and allows the call to carry further. Muscles within the body wall force the air back and forth between the lungs and vocal sac.
^Purgue, Alejandro. "Sound radiation and post-glottal filtering in frogs: Vocal Sac Resonators Revisited". acoustics.org. Acoustical Society of America. Retrieved 13 May 2019.
comparable anatomical structure that is referred to as either a gular sac, throat sac, vocalsac or gular fold. Gular skin can be very prominent, for example in...
vocal sac pigmentation is dictated by carotenoid levels, which must be ingested through food intake. Thus, the presence of conspicuous vocalsac coloration...
minutes, in order to better camouflage from predators. This frog has a vocalsac that expands and deflates like a balloon to create a short and distinct...
neck area, such as those caused by a double chin or the submandibular vocalsac of a frog. More generally, it can be any hanging mass of skin, such as...
female. Males have vocal cords and make a range of croaks, particularly in the breeding season, and in some species they also have vocalsacs to amplify the...
halfway down the back. The male's single vocalsac is internal. When it calls, the throat swells, but the vocalsac is not visible. The northern green frog...
beneath the mouth, which expands into the vocalsac. The female has a dark-spotted belly and lacks a vocalsac. The oak toad is native to the coastal regions...
"marsupium". In the frog Rhinoderma darwinii, the zygotes develop in the vocalsac. In the frog Rheobatrachus, zygotes develop in the stomach. Some insects...
part of the limbs are yellow/orange. They have acute hearing, but no vocalsac, and also lack nuptial pads. The goliath frog is mainly found near waterfalls...
through a system of air sacs and muscular phonic lips, which vibrate to produce audible vocalizations, thus serving the function of vocal folds in other mammals...
Microhylidae. Though its morphology lacks a tympanum (eardrum), the subgular vocalsac is clearly visible. The toes are long and unwebbed. The skin of G. carolinensis...
stubby, with a short rounded snout. The males have a paired internal vocalsac and three short ridges of small black spines along the inner surface of...
differentiated from related species by its green bilobate (two lobed) vocalsac and call that consists of one to four monophasic notes at a dominant frequency...
femoralis and Otophryne pyburni). Moreover, this species lacks an external vocalsac, so can only produce low-intensity calls that propagate short distances...
"marsupium"), and the frogs Rhinoderma darwinii (where the eggs develop in the vocalsac) and Rheobatrachus (where the eggs develop in the stomach). Histotrophic...
Jaw not in Aves Gums not in Aves Teeth not in Aves, Tusk Tongue Throat Vocalsac Ranidae Vertebral column (extends dorsally) Thorax Udder, Mammary gland...
sound is produced by expelling air from the lungs over the vocal cords into an air sac or sacs in the throat or at the corner of the mouth. This may distend...
during vocalization changes air sac pressure to control vocal intensity. The pressure in the interclavicular air sac is highly correlated with the fundamental...
on the ground. The male frog transports the tadpoles into his enlarged vocalsac. In the Chile Darwin's frog, the tadpoles are transported to a water source...
females and have a dark patch on their throats. The dark patch is the vocalsac, which stretches out when the male is calling. Pacific tree frogs can...
of the vocalsac, which recycles air and improves call rate and the distance which the sound travels. The bright white color of the vocalsac also provides...
false vocal folds which have a small sac between them. The vocal folds are sometimes called 'true vocal folds' to distinguish them from the 'false vocal folds'...
the light blue coloration observed in the axillary membranes and male vocalsac. The name was given as a tribute to the turquoise waters of a nearby river...
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