This most likely involves the closed mouth with the inflation of the vocal sac
. Previous studies have shown that the vocal sac
of anurans radiates a large proportion of the acoustic output and that when the mouth is open, the output becomes detuned and weakened [30, 31].
The Phylogenetic significante of vocal sac
structure in hylid frogs.
We also describe the cranium and vocal sac
structure of the new species.
It has yellow flanks with brown spots and a median, subgular vocal sac
. The call of S.
Only males have vocal sacs
. When one male begins calling, others often join in.
The body length is about 50-60 mm from snout to vent; throat is smooth; vocal sacs
are light brown; male has vocal slits under the lower jaw; dorsal side of the body is light grey, olive green or light brown, some times black with numerous scattered small smooth tubercles and irregular black spots; ventrum is white and smooth, immaculate or with dark speckling or reticulation (Khan and Tasnim, 1989).
Phrynohyas is one of four genera in the family Hylidae having paired lateral vocal sacs
. Four species of this genus are currently recognized according to size, structural features, coloration and cranial osteology (Duellman 1971).
Also, Feng says, video analysis suggests that a double set of vocal sacs
contributes to the animals' virtuosity.--S.M.