Bioacoustics of Duttaphrynus melanostictus

( Fig 4A ) Specimen examined: one male (WIIAD 242). Morphological characters : Adult male SVL 58.12 mm ; body stout; snout obtuse in dorsal and lateral view; prominent black cranial ridges over eyes; two large parotid glands behind eyes; pupil round; tympanum distinct and ¾ of the diameter of eye; dorsum skin warty, two longitudinal broken series of larger warts on dorsum; finger tips without discs; relative length of fingers II <I <IV <III; toes scarcely webbed, relative length of toes 1<2<3<5<4, inner metatarsal tubercle small and distinct. The calling male had single subgular highly distensible vocal sac. Coloration in life : Adult male pale yellow or brownish with reddish brown spots on dorsum, breeding males had orange colour on vocal sac region; edges of cranial ridge and upper lip black; series of larger warts on dorsum black; tips of fingers and toes black; underside pale white with fine white tipped spots. Bioacoustics: We recorded a calling male (voucher WIIAD 242 ) near a stagnant waterbody at 22:30 hours in July at air temperature 27.2 ° C. The male produced single type pulsatile calls. We analysed 10 advertisement calls. Calls were emitted mostly at regular intervals. The mean call duration was 64.1 ± 10.35 ms (44–70 ms) which was the shortest among all congeneric species recorded in PTR. Pulse rate was 112.39 ± 18.77 pulses/s (101.69–161.29 pulses/s) with mean number of pulses per call 6.8 ± 0.79 (5–8 pulses). The mean dominant frequency was 1701.15 ± 22.72 Hz (1679.6–1722.7 Hz ) ( Annexure II ) .