The Greater Sundas and Mainland Southeast Asia are the natural habitats of the Asian gigantic toad (Phrynoidis asper), also referred to as the river toad. Although it is a medium-sized toad, the gigantic river toad, which is its larger relative, might be mistaken for it (P. juxtasper).
Appearance
The tubercle-covered surface of Phrynoidis asper is often dark grey, green, black, or brown in colour. Snout-to-vent length in females can reach up to 14 cm (5.5 in), and in males it can reach up to 10 cm (3.9 in). They are frequently seen close to rivers and streams. The skull lacks bony crests and is large and flat. The supratympanic ridge connects the toad’s ovoid parotid gland to the supraorbital ridge. The tympanum can be seen. Spinous tissue covers the hands and feet. All toes save the fourth are fully webbed, and the fourth toe is the longest. On the base of the first finger of males, there are nuptial pads. Bufo asper typically has ventral black spots and is dark brown, gray, or black in hue. Males’ necks are a dark grayish tint.
The cup-shaped mouth and wide lower lip of the tadpole allow it to stick to the substrate at the bottom of moving water. Tadpoles are either entirely black or dark brown in hue.
Habitat
This species can be found up to 1500 meters above sea level in primary and old secondary rainforests in Malaysia, Indonesia, Thailand, Borneo, and Myanmar. Although there have not yet been any reports from neighbouring Cambodia and Laos, it is expected to also happen there.
Reproduction
Males call to females at night from numerous, widely spaced locations along the banks of the stream, especially when there is a full moon. The sound, which has been described as a raspy chirp and is occasionally repeated. They form no choruses. Given that both sperm and eggs are generated year-round, this species appears to reproduce continuously. The diameter of ripe ova is 1.26 mm. Large clutches of 12,792 eggs on average are laid by this species.
Relationship to People
In Sabah and Peninsular Malaysia, this frog is eaten as food.
Table
