Phrynoidis juxtasper, also known as the giant river toad or Borneo river toad, is a species of toad in the family Bufonidae. It is found in Borneo (Brunei, Indonesia, and Malaysia) and Sumatra (Indonesia) below 1600m (5,200feet) asl.[1] Prior to its species description, it was confused with Phrynoidis asper (hence the specific name juxtasper, from Latin juxta- meaning "near to").
Phrynoidis juxtasper are large toads: males grow to 122mm and females to 215mm in snout–vent length.[2] Habitus is stocky, but the limbs are relatively long. The snout is obtusely pointed. The tympanum is distinct. Supratympanic bony crests are thick and the parotoid glands are large. Skin bears large, round warts; ventral skin is granular. Warts of head, trunk, and limbs have melanic spinules on their tips. Toes have extensive webbing.
These toads can secrete large amounts of highly toxic, milky poison from their warts when disturbed. Eggs and tadpoles are also poisonous.[2]
Natural habitats of Phrynoidis juxtasper are primary and secondary forests, often along rocky creeks and riverbanks. They are good swimmers and jumpers.[2]
Phrynoidis juxtasper is a relatively adaptable species that is not facing significant threats. Large specimens are occasionally hunted for food.[2]