Energy Density of Three Prosopium Fish Species Endemic to Bear Lake, Utah–Idaho

Abstract

Abstract We used bomb calorimetry to quantify the energy density of three Prosopium fish species endemic to Bear Lake, Utah–Idaho, that we collected in 2020–2021: Bear Lake Whitefish Prosopium abyssicola, Bonneville Whitefish Prosopium spilonotus, and Bonneville Cisco Prosopium gemmifer. We found that mean ± standard deviation wet weight energy densities were 6,312 ± 760 J/g for Bear Lake Whitefish; 5,301 ± 778 J/g for Bonneville Whitefish; and 4,743 ± 443 J/g for Bonneville Cisco. We built linear mixed models and found relationships between energy density and dry matter ratio (i.e., ratio of dried weight to wet weight of a fish) for all three species, suggesting that the energy density of future samples collected in Bear Lake could potentially be determined from comparisons between the dried and wet weight of fishes belonging to these species. Our results are useful for future bioenergetics modeling with these three Bear Lake endemic species and potentially with others species in related genera that share similar feeding, behavior, and life-history traits.