Natural history and conservation of the rediscovered Hula painted frog, Latonia nigriventer

Dramatic global amphibian declines have recently led to an increased concern for many species of this animal class. The enigmatic Hula painted frog (Latonia nigriventer), the first amphibian to be declared extinct but unexpectedly rediscovered in 2011, has remained one of the rarest and most poorly understood amphibians worldwide. Gathering basic biological information on this species, along with an understanding of its disease-related threats remains fundamental for developing risk assessments and conservation strategies. Our surveys in recent years confirmed that L. nigriventer is a localised species with elusive habits. The species appears to follow an opportunistic breeding phenology and has a tadpole morphology similar to its well-studied sister group Discoglossus. However, the adults’ extended annual presence in the aquatic habitat is a major difference from species of Discoglossus. We detected the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), in northern Israel and on Hula painted frogs but did not observe any signs of chytridiomycosis in this species. Our preliminary data on aspects of the innate immunity of L. nigriventer suggest that the skin mucosome of this species contains antimicrobial peptides and a bacterial community differing from other syntopic frogs (Pelophylax bedriagae). The combined knowledge of both natural history and innate immunity of L. nigriventer provides valuable insights to direct future research and conservation management of this critically endangered frog species.