Diet affects body color and energy metabolism in the Baikal endemic amphipod <em>Eulimnogammarus cyaneus</em> maintained in laboratory conditions

Abstract

Proper diet is critical for laboratory-reared animals, as it may affect not only their welfare, but also experimental results. Amphipods (Crustacea: Amphipoda) play important roles in ecosystems and are often used in environmental research. Endemic amphipods from the ancient Lake Baikal are promising for laboratory bioassays; however, there are currently no laboratory cultures. In this work, we determine how different diets affect the color and metabolism of a laboratory-reared Baikal amphipod, Eulimnogammarus cyaneus. We found that in freshly collected blue-colored animals, body color correlated with total carotenoid content. Total carotenoid levels did not differ after long-term (two months) feeding with a close to natural carotenoid-enriched, or even a carotenoid-depleted diet. Nevertheless, antennae color was closer to red in the natural-like diet group. It is likely that the carotenoids from the commercial diet are not properly metabolized in E. cyaneus. The animals fed commercial diets had a higher glycogen content, which may signify a higher metabolic rate. Overall, we show that a carotenoid-enriched diet optimized for decapods is not optimal for amphipods, likely due to different carotenoid compositions, and the diet for long-term rearing of E. cyaneus and other Baikal amphipods requires supplementation.

Feeding Asian honeybee queens with European honeybee royal jelly alters body color and expression of related coding and non-coding RNAs

“…However, in the present study, the body-color alteration in honeybees induced by nutritional crossbreeding is an epigenetic phenomenon, since this alteration was based on exchanged larval diets. Nutrients can reverse or change epigenetic phenomena such as DNA methylation and histone modification in insects, altering the expression of critical genes related to development ( Choi and Friso, 2010 ), phenotype, and body color regulation ( Golic et al, 1998 ; Saranchina et al, 2021 ). The royal jelly of honeybees is a powerful food source that determines queen-worker caste differentiation ( Winston, 1991 ; Wojciechowski et al, 2018 ; Slater et al, 2020 ) through epigenetic modifications ( Maleszka, 2008 ; He et al, 2017 ).…”

“…Adding plant carotenoids to the diet of the Ornamental dwarf cichlid ( Microgeophagus ramirezi ) affects their color enhancement ( Padowicz and Harpaz, 2007 ). Diet can also affect body color in the Baikal endemic amphipod ( Eulimnogammarus cyaneus ) ( Saranchina et al, 2021 ). A recent study also confirmed that environmental factors could alter the body color of fruit flies, and this change can be passed to the next-generation ( Golic et al, 1998 ).…”