Cross-Life Stage Effects of Aquatic Larval Density and Terrestrial Moisture on Growth and Corticosterone in the Spotted Salamander

Julie Charbonnier,Kristine Grayson,Caitlin Gabor,James Vonesh,Jacquelyn Pearlmutter,Zachery Forsburg

doi:10.3390/d10030068

Julie Charbonnier, Kristine Grayson + Show 4 more

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https://doi.org/10.3390/d10030068

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Abstract

For organisms with complex life cycles, conditions experienced during early life stages may constrain later growth and survival. Conversely, compensatory mechanisms may attenuate negative effects from early life stages. We used the spotted salamander, Ambystoma maculatum, to test how aquatic larval density and terrestrial moisture influence juvenile growth, food intake, evaporative water loss and water reuptake rates, and corticosterone levels. We conducted an outdoor mesocosm experiment to manipulate larval density and transferred metamorphosed salamanders into low and high terrestrial moisture treatments in laboratory terrariums. After the larval stage, high-density salamanders were significantly smaller and had higher corticosterone release rates than those from low-density treatments. Salamanders in the low terrestrial moisture treatment consumed fewer roaches, had lower mass-specific growth rates, higher water reuptake, and higher corticosterone release rates than salamanders in high terrestrial moisture treatments. Across moisture treatments, smaller salamanders had higher mass-specific growth rates than larger salamanders. Our results suggest that salamanders can partially compensate for competition in the larval aquatic habitat with increased growth as juveniles, but this response is dependent on terrestrial habitat quality. Thus, the persistence of early life stage effects can be an important, yet context-dependent, component of amphibian life cycles.

Highlights

Organisms with complex life cycles pass through ecologically distinct stages during ontogeny and often relocate to new habitats during life history switch points [1]
High terrestrial moisture resulted in greater juvenile treatments had lower CORT release rates
High terrestrial moisture resulted in greater juvenile growth and and lower lower CORT

Summary

Introduction

Organisms with complex life cycles pass through ecologically distinct stages during ontogeny and often relocate to new habitats during life history switch points [1]. Ecological theory predicted that life history switch points allow modularity and independence across life stages by fundamentally remodeling organisms [1,2]. There is overwhelming evidence that life stages are interdependent and that variation in environmental quality experienced early in life can have a lasting impact on future performance of organisms [3,4,5,6]. These cross-life stage effects on phenotypes of later life stages are a type of developmental plasticity [7]. While numerous studies have documented cross-life stage effects across taxa, fewer have addressed how these effects may interact with conditions experienced in later life stages [5,8].

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