Dietary carotenoids and bacterial infection in wild and domestic convict cichlids (Amatitlania spp.)

作者：Brown Alexandria C; Cahn Matthew D; Choi Sara; Clotfelter Ethan D^*

来源：Environmental Biology of Fishes, 2016, 99(4): 439-449.

DOI：10.1007/s10641-016-0485-x

• Parasite
• Diet
• Trade-off
• Oxidative stress
• Immunity

Honest signaling of carotenoid-based ornaments may be reinforced by dietary limitation and by competing physiological demands for carotenoids. This study measured dietary carotenoids in a natural population of the convict cichlid Amatitlania siquia, a species in which females possess carotenoid-based ventral coloration. The zoonotic pathogen Edwardsiella spp. was detected in wild A. siquia, but carotenoids in the stomachs of wild fish did not vary significantly with parasite infection. We followed this with a laboratory experiment on domestic convict cichlids to test whether increased dietary carotenoid (-carotene) would decrease oxidative stress and facilitate clearance of experimental infections of Edwardsiella tarda. Fish maintained on a medium carotenoid diet (similar to the diets of wild fish) recovered from E. tarda infections more rapidly than fish on control diets, though fish on high carotenoid diets did not experience a similar benefit. There was an interaction between carotenoid diet and E. tarda such that uninfected fish on the medium carotenoid diet were significantly more colorful along their ventral surface compared to fish on the control and high carotenoid diets. Neither diet nor E. tarda infection affected oxidative damage, antioxidant capacity, or carotenoid content of the skin. From our field and laboratory data we conclude that carotenoid intake by wild convict cichlids occurs at a rate sufficient to affect bacterial infection and ventral coloration, but more data are needed from wild populations to verify the functional significance of these interactions.

• 出版日期2016-4