Functional niche partitioning occurs over body size but not nutrient reserves nor melanism in a polar Carabid beetle along an altitudinal gradient

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Authors

Espel, Diane
Coux, Camille
Pertierra, Luis R.
Eymar-Dauphin, Pauline
Lembrechts, Jonas J.
Renault, David

Journal Title

Journal ISSN

Volume Title

Publisher

MDPI

Abstract

Phenotypic plasticity can favor the emergence of different morphotypes specialized in specific ranges of environmental conditions. The existence of intraspecific partitioning confers resilience at the species scale and can ultimately determine species survival in a context of global changes. Amblystogenium pacificum is a carabid beetle endemic to the sub-Antarctic Crozet Islands, and it has two distinctive morphotypes based on body coloration. For this study, A. pacificum specimens of functional niches were sampled along an altitudinal gradient (as a proxy for temperature), and some morphological and biochemical traits were measured. We used an FAMD multivariate analysis and linear mixed-effects models to test whether these traits were related to morphotype, altitude, and sexual dimorphism. We then calculated and compared the functional niches at different altitudes and tested for niche partitioning through a hypervolume approach. We found a positive humpshaped correlation between altitude and body size as well as higher protein and sugar reserves in females than in males. Our functional hypervolume results suggest that the main driver of niche partitioning along the altitudinal gradient is body size rather than morphotype or sex, even though darker morphotypes tended to be more functionally constrained at higher altitudes and females showed limited trait variations at the highest altitude.

Description

DATA AVAILABILITY STATEMENT : The data presented in this study are openly available on FigShare at https://doi.org/10.6084/m9.figshare.21444753.v1 and on GitHub at https://github.com/CamilleCoux/ A_pacificum/tree/main/data. The R scripts from the analyses in this article are available on GitHub at https://github.com/CamilleCoux/A_pacificum.

Keywords

Amblystogenium pacificum, Carabidae, Functional diversity, French sub-Antarctic islands, Thermal tolerance, Melanism, Dimorphism, Thermal tolerancex, SDG-15: Life on land

Sustainable Development Goals

SDG-15:Life on land

Citation

Espel, D.; Coux, C.; Pertierra, L.R.; Eymar-Dauphin, P.; Lembrechts, J.J.; Renault, D. Functional Niche Partitioning Occurs over Body Size but Not Nutrient Reserves nor Melanism in a Polar Carabid Beetle along an Altitudinal Gradient. Insects 2023, 14, 123. https://doi.org/10.3390/ insects14020123.