Abstract
Carotenoids are diverse lipophilic natural pigments which are stored in variable amounts by animals. Given the multiple biological functions of carotenoids, such variation may have strong implications in evolutionary biology. Crustaceans such as Gammarus amphipods store large amounts of these pigments and inter-population variation occurs. While differences in parasite selective pressure have been proposed to explain this variation, the contribution of other factors such as genetic differences in the gammarid ability to assimilate and/or store pigments, and the environmental availability of carotenoids cannot be dismissed. This study investigates the relative contributions of the gammarid genotype and of the environmental availability of carotenoids in the natural variability in carotenoid storage. It further explores the link of this natural variability in carotenoid storage with major crustacean immune parameters. We addressed these aspects using the cryptic diversity in the amphipod crustacean Gammarus fossarum and a diet supplementation protocol in the laboratory. Our results suggest that natural variation in G. fossarum storage of dietary carotenoids results from both the availability of the pigments in the environment and the genetically-based ability of the gammarids to assimilate and/or store them, which is associated to levels of stimulation of cellular immune defences. While our results may support the hypothesis that carotenoids storage in this crustacean may evolve in response to parasitic pressure, a better understanding of the specific roles of this large pigment storage in the crustacean physiology is needed.
Highlights
Carotenoids are diverse, lipophilic, biologically active natural pigments produced by photosynthetic micro-organisms, algae and plants
Because they are involved in many biological functions [1,5], carotenoids may have strong implications in evolutionary biology, by impacting individual health, performance, and fitness
Within each molecular operational taxonomic units (MOTUs), carotenoid concentrations differed between gammarid populations (Table 3)
Summary
Carotenoids are diverse, lipophilic, biologically active natural pigments produced by photosynthetic micro-organisms, algae and plants. Natural variation in crustacean carotenoids animals vary across taxa [9,10] and within species [11], suggesting variability in their physiological importance, and/or fluctuations in their environmental availability, but the contributions of and interactions between genetics and environment remain not well understood. Because they are involved in many biological functions [1,5], carotenoids may have strong implications in evolutionary biology, by impacting individual health, performance, and fitness. Beneficial effects of carotenoids were often secondarily derived from their conversion into downstream products, such as conversion of beta-carotene into vitamin A (crucial in the embryonic development), and directly from non-provitamin A xanthophyll carotenoids such as astaxanthin and lutein, mainly produced by fungi, algae, and plants [2,29,30,31]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
