Fatty acid composition of two terrestrial and two marine decapod crustaceans from Taiwan

Males of the four crab species Percnon affine (H. Milne Edwards, 1853), Grapsus albolineatus (Latreille in Milbert, 1812), Orisarma intermedium (Schubart &Ng, 2020), and Geothelphusa albogilva (Shy, Ng & Yu, 1994), were collected in the southern part of Taiwan in May 2007. Individuals were starved for 12 days and midgut glands were dissected before and after the starvation period. Midgut glands were lyophilized and total lipids were extracted with dichloromethane:methanol (2:1 per volume) and an aqueous solution of 0.88% KCl. Extracted lipid mass was determined gravimetrically. Lipid classes were separated and quantified using Thin-Layer Chromatography with an integrated flame ionization detector (MK-5 TLC/FID analyzer, Iatron Laboratories). Lipids were converted to fatty acids methyl esters (FAME) by applying methanol containing 3% concentrated sulfuric acid. FAMEs were quantified by gas chromatography equipped with a DB-FFAP column, a programmable temperature vaporizer injector, and a flame ionization detector. Helium was used as carrier gas. Fatty acids were identified by retention times and by using fish oil standard (Marinol). Data are supplement to: Stumpp et al (2021) Dietary preferences of brachyuran crabs from Taiwan for marine or terrestrial food sources: evidence based on fatty acid trophic markers accepted for publication in Frontiers in Zoology