Major histocompatibility complex (MHC) genes determine immune repertoires and social preferences of vertebrates. Immunological regulation of microbial assemblages associated with individuals influences their sociality, and should also affect their life-history traits. We exposed Xenopus laevis tadpoles to water conditioned by adult conspecifics. Then, we analysed tadpole growth, development and...

Diploid frog nuclei from differentiated somatic cells, transplanted into enucleated eggs to determine whether cell specialization generally involves irreversible genetic changes, have shown that nuclei from specialized somatic cells still contain the genes specifying the cell types and organ systems of swimming tadpoles. However, those tadpoles failed to feed and did not survive beyond the init...

Understanding negative effects of native species on introduced taxa may suggest novel ways to control the invasive species by enhancing such effects. Previous studies have reported that the larvae of invasive cane toads (Rhinella marina) are suppressed by competition with the larvae of native anurans in Australia, but not in North America. We conducted laboratory trials to measure the effect of...

We examined the effect of embryonic olfactory experiences on behaviour after hatching in two species of anuran amphibians, Rana temporaria and Rana sylvatica. Odorants (orange and citral) injected into the egg were "learned" by the embryo and subsequently preferred by tadpoles after hatching. The observed preferences were specific to the odours experienced prior to hatching, and tadpoles discri...

On Taboga Island, Republic of Panama, a grapsid crab, Armases angustum (Smith, 1870), was found in one of the treeholes of a buttress tree that was used heavily by Dendrobates auratus Girard, 1855 for breeding. The crab ate tadpoles in captivity and thus is a new potential predator of D. auratus. D. auratus is a species of terrestrial frog with parental care. After a lengthy courtship, females ...

We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adul...

The role of growth hormone (GH) in amphibian metamorphosis is ambiguous based on experiments in which mammalian GH was administered to tadpoles and frogs. We have reexamined the effects of GH by producing transgenic Xenopus laevis that overexpress the cDNA encoding X. laevis GH. These transgenic tadpoles take the same length of time to reach metamorphosis as control tadpoles, but the transgenic...

UNLABELLED Ranaviruses (Iridoviridae) are posing an increasing threat to amphibian populations, with anuran tadpoles being particularly susceptible to these viral infections. Moreover, amphibians are the most basal phylogenetic class of vertebrates known to possess both type I and type III interferon (IFN)-mediated immunity. Moreover, little is known regarding the respective roles of the IFN me...

Ranavirus (family Iridoviridae) is a genus of pathogens of poikilotherms, and some ranaviruses may play a role in widespread mortality of amphibians. Ecology of viral transmission in amphibians is poorly known but can be addressed through experimentation in the laboratory. In this study, we use the Ranavirus frog virus 3 (FV3) as an experimental model for pathogen emergence in naive populations...