Chemical composition of food induces plasticity in digestive morphology in larvae ofRana temporaria

Abstract

Food conditions are changing due to anthropogenic activities and natural sources and thus, many species are exposed to new challenges. Animals might cope with altered quantitative and qualitative composition [i.e. variable protein, nitrogen (N) and energy content] of food by exhibiting trophic and digestive plasticity. We examined experimentally whether tadpoles of the common frog (Rana temporaria) exhibit phenotypic plasticity of the oral apparatus and intestinal morphology when raised on a diet of either low (i.e. Spirulina algae) or high protein, N and energy content (i.e. Daphnia pulex). Whereas intestinal morphology was highly plastic, oral morphology did not respond plastically to different chemical compositions of food. Tadpoles that were fed food with low protein and N content and lowenergy density developed significantly longer guts and a larger larval stomachs than tadpoles raised on high protein, N and an energetically dense diet, and developed a different intestinal surface morphology. Body sizes of the treatment groups were similar, indicating that tadpoles fully compensated for low protein, N and energy diet by developing longer intestines. The ability of a species, R. temporaria, to respond plastically to environmental variation indicates that this species might have the potential to cope with new conditions during climate change.

Thermal tolerance and acclimation capacity in the European common frog (Rana temporaria) change throughout ontogeny

“…This study identifies young larvae as the most‐temperature‐sensitive life stages in the life cycle of R. temporaria and highlights that early life stages might define the climate change vulnerability of amphibian populations. Given that this widely distributed species possesses a high capacity for developmental (Laurila & Kujasalo, 1999; Lind & Johansson, 2007; Merilä et al, 2004), morphological (Ruthsatz, Giertz, et al, 2019), and physiological plasticity (present study; Burraco et al, 2017; Ruthsatz, Dausmann, Reinhardt, et al, 2020), compared to other amphibian species (Laurila & Kujasalo, 1999; Ruthsatz et al, 2018; Vences et al, 2017), this bottleneck in the life cycle might be more pronounced in the vast majority of amphibian populations and species. Much of what is currently known about acclimation capacity in amphibians and other ectotherms has been gained from studies conducted on adults or from meta‐analyses that pool data across life stages (rev.…”

Description and shaping factors of diet and feeding ecology of neotropical tadpoles: A case study and a comprehensive review

“…Also, digestibility of different food items was not accessed in any of the published articles reporting natural diets of neotropical tadpoles, indicating a huge knowledge gap. Some studies addressed assimilation efficiency under different temperatures and diets (Benavides et al, 2005) or effects of different diets on growth, development (Toledo et al, 2014) and morphological plasticity (Castañeda et al, 2006;Ruthsatz et al, 2019Ruthsatz et al, , 2022, but they all used manipulated/artificial diets that did not correspond to what tadpoles eat in situ. The investigation of natural diets is important because even if nutritional composition of artificial diets mirror natural ones, digestibility is likely to vary among food items (Pryor, 2014) and play a role on the benefits of each diet, as assimilation of consumed items vary (Schmidt et al, 2017).…”

Ingestion of Poisonous Eggs of the Invasive Apple Snail Pomacea canaliculata Adversely Affects Bullfrog Lithobathes catesbeianus Intestine Morphophysiology

“…This is possible because the small intestine has the shortest turnover rate of all tissues in the body and, at least in mammals, it takes only 3 days to cover the entire surface with new cells. Likewise, studies on gut plasticity in amphibian, mostly performed in tadpoles (Naya et al 2005;Ruthsatz et al 2019), show that anurans have adaptive mechanisms that modify the activity of gastrointestinal tract (Cramp and Franklin 2005;Seliverstova and Prutskova 2012). Changes in the relative amount of collagen fibers may be related to gut reaction after ingestion of snail PVF and associated with a remodeling process although more work is needed to fully understand this issue.…”