Fatty acids were extracted and analysed from freeze-dried samples (3–10 mg dry mass) that were homogenized, sonicated and vortexed (4 times) in a chloroform-methanol (2:1) mixture, following Böhm et al. (2014). Total lipid mass ratios were determined via gravimetry. Fatty acids were derivatized to obtain fatty acid methyl esters (FAME) using toluene and sulfuric acid-methanol-solution (incubated at 16 h at 50 C). FAME were identified using a gas chromatograph (Thermo Scientific TRACE GC Ultra) equipped with a flame ionization detector (FID) and a Supelco SP-2560 column (100 m, 25 mm i.d., 0.2 mm film thickness). Quantification of fatty acids were performed by comparison with a known concentration of the internal standard using Excalibur 1.4 (Thermo Electron Corporation).