Nothing as it seems: behavioural plasticity appears correlated with morphology and colour, but is not in a Neotropical tadpole

Abstract

In response to environmental stressors, organisms often demonstrate flexible responses in morphology, life history or behaviour. However, it is currently unclear if such plastic responses are coordinated or operate independently of one another. In vertebrates, this may partly result from studies examining population- or species-level mean responses, as opposed to finer grained analyses of individuals or families. We measured predator-specific morphological and coloration plasticity in 42 families of tadpoles of the treefrog Dendropsophus ebraccatus and behavioural plasticity from 18 of these families, allowing us to examine the correlation between three predator-induced plastic responses. For all three plastic responses, tadpoles showed strong opposing responses to each of two predators, providing the appearance of covariation in plasticity. However, the examination of individual families revealed a strong correlation between morphological and coloration plasticity, but no correlations between either morphology or colour and behavioural plasticity. Thus, our analysis shows that some aspects of the plastic phenotype develop together while others function independently. This highlights the importance of examining individual- and family-level variation for understanding the adaptive significance of developmental plasticity, which is crucial for a holistic appreciation of phenotypic plasticity and its importance in ecology and evolution.

Plasticity and flexibility in the anti-predator responses of treefrog tadpoles

“…1). Similar results were observed in tadpoles of the treefrog Dendropsophus embraccatus, whose behavioral responses to predators were affected by the exposure to predator cues in both the ontogenetic and acute treatments (Reuben and Touchon 2021). The phenotypic effects of the environment exerted at different time scales have been described as a case of sequential multidimensional plasticity (Westneat et al 2019), where a stimulus experienced early in life influences how it will be perceived and processed later.…”

Maintenance of phenotypic plasticity is linked to oxidative stress in spadefoot toad larvae

“…We included in our analyses the first four relative warps, which explained 31.0, 19.0, 11.0 and 9.4% of the total morphometric variance, respectively. These warps explained variation in common morphological features previously described for amphibian larvae (Rufino et al 2006, Reuben andTouchon 2021).…”

“…Such costs refer solely to the maintenance itself of the mechanisms needed to detect and respond to environmental inputs, and are different from ‘production costs', which are those paid by organisms during the actual production or expression of alternative phenotypes (DeWitt et al 1998, Teplitsky et al 2005). The genetic and sensory machinery regulating phenotypic plasticity and their maintenance is still incomplete and therefore further empirical data is needed (Beldade et al 2011, Kelly et al 2011, Reuben and Touchon 2021).…”

Predator‐induced shape plasticity in Daphnia pulex

“…While this approach has been used to measure predator‐induced changes in shape for a wide range of organisms, such as fish (Arnett & Kinnison, 2016 ; Díaz‐Gil et al., 2020 ; Franssen, 2011 ), amphibians (Florencio et al., 2020 ; Reuben & Touchon, 2021 ; Ruehl et al., 2018 ) and snails (Hooks & Padilla, 2021 ; Solas et al., 2015 ; Terry & Duda, 2021 ), until recently, shape has rarely been assessed as a plastic trait in water fleas ( Daphnia species), an iconic organism for the study of size‐selective, predator‐induced phenotypic change. Instead, daphnid research has largely focused on scoring the production of inducible morphological defences, such as the head spikes of Daphnia pulex , called ‘neckteeth’, which develop in response to predator cues (kairomones) released from their midge larvae predators (Krueger & Dodson, 1981 ; Parejko & Dodson, 1991 ; Tollrian, 1993 ).…”

“…While this approach has been used to measure predatorinduced changes in shape for a wide range of organisms, such as fish (Arnett & Kinnison, 2016;Díaz-Gil et al, 2020;Franssen, 2011), amphibians (Florencio et al, 2020;Reuben & Touchon, 2021;Ruehl et al, 2018) and snails (Hooks & Padilla, 2021;Solas et al, 2015;Terry & Duda, 2021), until recently, shape has rarely been assessed as a plastic trait in water fleas (Daphnia species), an iconic organism for the study of size-selective, predator-induced phenotypic change.…”