The familiy of Firebelly Toads contains only nine species worldwide; two of them occur in the Sunda Region (genus Barbourula). Seven species are known within the genus Bombina, which is found on mainland Eurasia.

The only Barbourula recorded for Borneo is Barbourula kalimantanensis. The latter had been declared the only lungless frog in the world, however, more recent investigations have shown that lungs are present.  

Until recently, the reproductive of Barbourula species have been unknown and much speculated about. Recently, however, Miñarro et al. (2024) discovered and described the tadpoles of Barbourula busuangensis from the Philippines and expanded our knowledge on the reproductive biology of the species, and presumably all species in the genus, significantly

Miñarro et al. (2024) wrote that B. busuangensis "exhibits characteristics of a K-strategist, with large, unpigmented eggs in small number relative to body size." Their field observations suggest "a prolonged reproductive period, with gravid females present across seasons, and possible egg retention for at least up to two months." They found that tadpoles were rheophilous, endotrophic (non-feeding), and nidicolous (not leaving the nest site). The tadpoles lacked keratinized mouthparts and had a large sucker-like oral disc with which they for adhered to the rock face in crevices in river-bed cave systems. The team successfully made camera recordings at nest sites that revealed the presence of an adult with the larvae, suggesting parental care. These reproductive features were proposed to be a "new, undescribed reproductive mode for anurans, thus contributing to our knowledge on the evolution of reproductive strategies of tropical species in different ecological contexts."