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Diving as a lifestyle has evolved on multiple occasions when air-breathing terrestrial animals invaded the aquatic realm, and diving performance shapes the ecology and behaviour of all air-breathing aquatic taxa, from small insects to great whales. Using the largest dataset yet assembled, we show that maximum dive duration increases predictably with body mass in both ectotherms and endotherms. Compared to endotherms, ectotherms can remain submerged for longer, but the mass scaling relationship for dive duration is much steeper in endotherms than in ectotherms. These differences in diving allometry can be fully explained by inherent differences between the two groups in their metabolic rate and how metabolism scales with body mass and temperature. Therefore, we suggest that similar constraints on oxygen storage and usage have shaped the evolutionary ecology of diving in all air-breathing animals, irrespective of their evolutionary history and metabolic mode. The steeper scaling relationship between body mass and dive duration in endotherms not only helps explain why the largest extant vertebrate divers are endothermic rather than ectothermic, but also fits well with the emerging consensus that large extinct tetrapod divers (e.g. plesiosaurs, ichthyosaurs and mosasaurs) were endothermic.

Promiscuity, explosive breeding and male-biased operational sex-ratios can affect the strength of male selectivity and may play major roles in the expression of misdirected matings (with conspecific males, other species, corpses or objects) in anuran amphibians. Yet, misdirected amplexus occur in multiple species diverging from these reproductive traits, suggesting that the expression of such behaviour is widespread, and may have occurred early during anuran diversification. Using two methods of ancestral-trait reconstruction which predict unknown states, we found a very high probability that most anuran genera express misdirected amplexus, suggesting that this by-product of anuran reproductive strategies is likely to have occurred early during anuran diversification. The persistence of misdirected amplexus suggests that its infrequent occurrence may outweigh individual costs of breeding attempts with unfit mates. We found a recent exponential increase in reported observations of misdirected amplexus, which, along with increased research effort and publication rate, may reveal an effect of environmental perturbations known to promote the occurrence of these behaviours. [ABSTRACT FROM AUTHOR]

Assessing the determinants of reproductive success is critical but often complicated because of complex interactions between parental traits and environmental conditions occurring during several stages of a reproductive event. Here, we used a simplified ecological situation—an amphibian species lacking post-oviposition parental care—and a laboratory approach to investigate the relationships between parental (both maternal and paternal) phenotypes (body size and condition) and reproductive success (fecundity, egg size, embryonic and larval duration, larval and metamorphic morphology). We found significant effects of maternal phenotype on fecundity, hatching success, and tadpole size, as well as on the duration of larval development. Interestingly, and more surprisingly, we also found a potential contribution of the paternal phenotype occurring during early (embryonic development duration) offspring development. Although our study focused on life-history traits such as body size and development duration, additional mechanisms involving physiological costs of development may well mediate the relationships between parental phenotypes and offspring development. Future studies are required to decipher the mechanisms underlying our findings in order to clarify the mechanistic basis of the links between parental phenotypes and offspring development. [ABSTRACT FROM AUTHOR]