An inter-order comparison of copepod fatty acid composition and biosynthesis in response to a long-chain PUFA deficient diet along a temperature gradient

Copepods serve as a major link in marine food webs, bridging the energy transfer from primary producers to higher trophic levels. Oceanic warming is linked reduced concentrations of essential fatty acids (FA) phytoplankton, namely eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic (DHA, 22:6ω3), it remains largely unknown if copepods have capacity endure. The calanoid Temora longicornis harpacticoid Platychelipus littoralis were chosen analyse their FA biosynthesis activity response long-chain polyunsaturated (LC-PUFA) deficient diet (Dunaliella tertiolecta) along temperature gradient. fed D. tertiolecta labelled with stable isotope carbon-13 (13C) quantify carbon assimilation into total de novo EPA DHA after 6 days incubated at 11, 14, 17, 20 23 °C. had increased mortality warming, whereas exhibited high survival across thermal After incubation, P. assimilated minimal amounts dietary its comparison T. longicornis. depleted field stores more rapidly, maintained relative storage absolute DHA. displayed fractions than all temperatures, exception Within our experimental incubation period both species unable meaningfully upgrade LC-PUFA algae biosynthesize relevant source for