Morphometrics, Habitat and Breeding Activity of Asian Common Toad, <i>Duttaphrynus melanostictus</i>, in Pakistan

Abstract

The scientific data on ecology of amphibians from Pakistan are scarce. Asian Common Toad (Duttaphrynus melanostictus) is widely distributed in South Asia, and has been introduced outside its range causing severe ecological problems. We gathered data on morphometrics, habitat and breeding activity of the species in its western edge, North Punjab, Pakistan, of the range. The morphometric measurements of Asian Common Toad showed that the males were 49 ± 3.4 mm in snout vent length while the females were 58 ± 5.5 mm. Of the 13 measurements tested, the factor analysis produced five (head width, forelimb length, femur length, width of upper eyelid and foot length) significant measurements (r 0.80) for male while six (snout-vent length, head width, head length, greatest tympanum diameter, forelimb length, length of tarsus and foot) for female. The substrate of the habitat of Asian Common Toad was recorded as muddy to stony; water with neutral to slightly alkaline pH; dominated by herbs: Cannabis sativa, Parthenium hysterophorus; shrubs: Dodonaea viscosa, Lantana camara; grasses: Cynodon dactylon, Dactyloctenium aegyptium; and hydrophytes Alternanthera sessilis and Centella asiatica. The mean air and water temperature (day) during the breeding period were 27 – 30.5 and 25 – 28.5°C, respectively. The toad species laid eggs in small sized pools with lentic to slow-moving water with the mean depth of 32 – 64 cm. The males were more abundant than females (2.14♂:1♀) at the breeding sites. The advertisement call was of 9.3 ± 0.80 sec duration with a single note and 49.5 ± 6.5 nodes, –7.45 ± 0.95 average amplitude, 776 ± 51.8 Hz minimum frequency and 7011 ± 1680 Hz maximum frequency.