Differences in Fatty Acid Composition between Orb-Weaver Spiders Inhabiting a Riparian Zone and a Steppe Are Associated with the Consumption of Different Chironomid Taxa.

ABSTRACT

Amphibiotic insects, chironomids of the genera Glyptotendipes and Chironomus, which emerged from saline Lake Shira, differed in composition and content of fatty acids, including the essential eicosapentaenoic acid (205n-3, EPA), and upon flying out they were concentrated in different territories, the riparian zone and remote arid steppe zone, respectively. Potential consumers of chironomids adults, the orb-weaver spiders Larinoides suspicax, which inhabited both zones, also differed in fatty acid composition. The main difference in their biochemical composition was a significantly higher level of EPA in spiders from the riparian zone that likely to be explained by consumption of the Glyptotendipes adults enriched in this fatty acid and concentrated only within this zone. The higher level of EPA, which is deficient in terrestrial ecosystems, in orb-weaver spiders from the riparian zone of the saline lake may potentially promote a successful survival of the consumers in the arid landscape.