Made of Other Stuff: Membrane Lipid Composition and Function of Deep, Shallow, Cold and Warm Ctenophores

Gelatinous organisms like ctenophores comprise a major component of midwater animal biomass. With little physical protection for their cells, such animals rely on biochemical adaptation to survive in diverse and often extreme habitats. The composition of lipids, which make up cell membranes, is central to environmental adaptation in a wide range of organisms. The new ctenophore lipidomics dataset presented here extends beyond established relationships between fatty acid unsaturation, temperature, and pressure to explore other important aspects of membrane chemistry, such as headgroup composition, novel fluidizing compounds, and antioxidant content. This is also the first comparative study of animal membrane biochemistry carried out in a phylogenetic context. Focal taxa were chosen to leverage the rich taxonomic and habitat diversity of ctenophores, representing all four orders and four distinct habitats that range in depth from sea level to 4000 meters, and in temperature from -2° to 25° C. Findings are relevant to midwater trophic ecology, as they inform differing requirements for carbon metabolism in different physical environments, and could aid in identifying dietarily essential organic compounds.