Effect of temperature on the fatty acid composition and temporal trajectories of fatty acids in fasting Daphnia pulex (Crustacea, cladocera)

Abstract

Poikilothermic organisms accumulate highly unsaturated FA (HUFA) in their lipids at reduced temperatures to maintain cell membrane fluidity. In this study we investigated the effect of temperature on temporal trajectories of FA of fasting Daphnia pulex cultured on a HUFA-free diet. Daphnia pulex populations were maintained for 1 mon at 22 and 11 degrees C and were fed the chlorophyte Ankistrodesmus falcatus. We observed conversion of C18 FA precursors to EPA (20:5n3) and arachidonic acid (ARA; 20:4n6) in D. pulex. We showed that long-term exposure to cold temperature causes a significant increase in EPA. HUFA such as ARA and EPA are highly conserved during starvation. Therefore, D. pulex has the biosynthetic capacity to adjust and to maintain the content of HUFA required to survive at low temperatures.

Global Warming: Testing for Direct and Indirect Effects of Temperature at the Interface of Primary Producers and Herbivores Is Required

“…In line with the concept of homeoviscous adaptation, decreased ambient temperatures result in increased levels of EPA content in Daphnia (Schlechtriem et al, 2006;Sperfeld and Wacker, 2012), which suggests a higher sensitivity to EPA-limitation at lower temperatures. Supplementation with EPA-containing liposomes confirmed a higher degree of EPAlimitation of Daphnia when growing at 15 • C compared to 20 • C (Sperfeld and Wacker, 2012).…”

“…Although both studies (Schlechtriem et al, 2006;Sperfeld and Wacker, 2012) provide clear evidence for an increased EPArequirement at lower temperatures, neither study demonstrates that EPA-limitation of growth of Daphnia increases at lower temperatures: temperature was experimentally varied only for the growth of Daphnia, whereas in all Daphnia growth experiments the same algal food source, which was cultivated at a single temperature only, was used. Hence, from both studies (Schlechtriem et al, 2006;Sperfeld and Wacker, 2012) it cannot be predicted, how temperature changes that affect producer and consumer would affect the degree of EPA-limitation in Daphnia.…”

“…Hence, from both studies (Schlechtriem et al, 2006;Sperfeld and Wacker, 2012) it cannot be predicted, how temperature changes that affect producer and consumer would affect the degree of EPA-limitation in Daphnia. The reason is that phytoplankton's fatty acid composition is as well affected by ambient temperatures.…”

Tracing aquatic food webs using fatty acids: from qualitative indicators to quantitative determination

“…12.2.1) are generally thought to have a greater capacity to modify (elongate or desaturate) dietary FA than higher animals. Freshwater Daphnia were shown to elongate/desaturate 18:3n-3 to 20:5n-3 (Schlechtriem et al 2006) . However even in these invertebrates, direct incorporation of dietary FA has been demonstrated (Sargent and Henderson 1986;Dalsgaard et al 2003) .…”

Structural Elucidation of the Neutral Glycosphingolipids, Mono-, Di-, Tri- and Tetraglycosylceramides from the Marine Crab Erimacrus isenbeckii

“…Many poikilothermic animals adapt to changing environmental temperatures by modifying the degree of unsaturation of their lipids 42,43 . For example, in fasting Daphnia pulex Crustacea, Cladocera , long-term exposure to cold temperature causes a significant increase in EPA 20:5 content 44 . There is other abundant evidence that the stability and fluidity of biological membranes are functions of the saturated and unsaturated fatty acid composition of the lipid bilayer.…”