Both Incubation Temperature and Posthatching Temperature Affect Swimming Performance and Morphology of Wood Frog Tadpoles (Rana sylvatica)

Abstract

In many oviparous vertebrates, hatchling phenotypes are influenced by egg incubation temperature. Many of those phenotypic traits can also acclimate to long-term thermal conditions of juveniles and adults, yet the interactive effects of prehatching and posthatching temperatures on phenotypes have not been studied. To address such interaction, we incubated eggs of wood frogs (Rana sylvatica) at two temperatures and subsequently reared larvae at three temperatures in a fully factorial design. We measured body size, size-independent morphology, and burst swimming speed at one developmental stage. Body size was independent of egg temperature but decreased significantly with increasing larval temperature. Size-independent morphology depended in complex ways on both temperature treatments directly and on their interaction. Burst speed was not influenced directly by egg temperature but was influenced by larval temperature and by the interactions among egg temperature, larval temperature, and test temperature. Our results indicate pervasive effects of egg temperature even late in the larval period and show that prehatching and posthatching temperatures can interact to affect various phenotypic traits. Tadpoles may be able to alter the long-term effects of incubation temperature by choosing particular larval developmental temperatures. Thus, the importance of incubation temperature in oviparous vertebrates should be evaluated by considering the effects of posthatching temperatures.

Effects of temperature on embryonic and early larval growth and development in the rough-skinned newt (Taricha granulosa)

“…Similar to our results, Watkins and Vraspir (2006) found embryonic and larval developmental temperatures significantly affected larval wood frog (Lithobates sylvaticus) morphology. These effects resulted in altered swimming performance, which has important survival implications (Watkins and Vraspir, 2006). Considering that smaller, less developed larvae are more susceptible to pollution (Beebee, 1986;Cooke, 1979;Hopkins et al, 2014) and predators (Anderson et al, 2001;Boone et al, 2002;Gall et al, 2011;Touchon et al, 2013;Warkentin, 1995), the carry-over effects of embryonic temperature in salamanders and newts could have survival consequences in later life stages.…”

“…For instance, predator avoidance and insecticide sensitivity during the larval stage has been shown to be affected by embryonic rearing temperature in an Australian frog (Limnodynastes peronii) (Broomhall, 2004). Similar to our results, Watkins and Vraspir (2006) found embryonic and larval developmental temperatures significantly affected larval wood frog (Lithobates sylvaticus) morphology. These effects resulted in altered swimming performance, which has important survival implications (Watkins and Vraspir, 2006).…”

The trade-off between growth rate and locomotor performance varies with perceived time until breeding

“…Such growthinduced differences in muscle structure have been shown in herring (Clupea harengus) to translate into differences in swimming performance that persist even when fish are subsequently growing at the same rate (Johnston et al, 2001). Effects of embryonic conditions on muscle development and subsequent motor performance are not restricted to fish: effects of early growth rate on tail muscle fibre numbers and swimming performance have been found in tadpoles of both toads (Arendt and Hoang, 2005) and frogs (Watkins and Vraspir, 2006), and it has been suggested that such a trade-off between early growth rate and locomotor performance is common to all vertebrates (Arendt, 2003).…”

The Physiological Basis of Geographic Variation in Rates of Embryonic Development within a Widespread Lizard Species

“…In a wide range of organisms, the conditions under which an embryo develops alter the organism's phenotype in later life (Deeming 2004;Watkins and Vraspir 2006). Given the sensitivity of developmental trajectories to local conditions, one of the most intriguing questions involves conservatism in phenotypic traits in wide-ranging species.…”