ABSTRACT
Amphibians have the striking diversity of reproductive modes among terrestrial vertebrates in terms of breeding habitat, fertilisation, developmental flexibility and parental care. Here we review the diversity of reproductive modes and recent advances in amphibian breeding biology. The reproduction of several species has been recently uncovered, and some of these studies revealed new ways of caring for example mud-packing in frogs or skin-feeding in caecilians. In addition, cost and benefit analyses using a behavioural ecological framework has identified the fitness implications of complex reproduction. Parallel to these advances, evolutionary and comparative biology techniques have been advanced to resolve ancestral states of the reproductive traits and identified predictors of phylogenetic transitions from ancestral conditions toward advanced parenting. Studies revealed that a major driving force of inventing new reproductive modes was gaining independence from breeding in aquatic habitats. During the transition toward terrestrial reproduction, amphibians faced with new challenges that include desiccation of eggs, terrestrial egg predators and new pathogens that attack the eggs and the developing larvae. Taken together, amphibian reproduction has remained an exciting system to investigate early vertebrate evolution. It is also an urgent priority that will facilitate the persistence of numerous amphibian species that are sadly globally threatened.
