Abyssal holothurians were collected during SO242-2 in the Peru Basin in 2015 with ROV Kiel 6000 (Geomar, Germany). Aboard the vessel, holothurians were measured (length, width, height), dissected and stored frozen (-20°C). At the shore-based laboratory of NIOZ-Yerseke, samples were weight before and after freeze-drying and organic (org.) C/ δ13C and N/ δ15N content of freeze-dried, finely-ground holothurian body wall tissue were measured with an elemental analyzer coupled with an isotope ratio mass spectrometer. Total hydrolizable amino acids (THAA) from holothurian body wall tissue were extracted following a modified protocol of Veuger et al. 2005. Phospholipid-derived fatty acids (PLFAs) and neutral lipid-derived fatty acids (NLFAs) were extracted from holothurian body wall tissue and gut content following a modified Bligh and Dyer extraction method.

μmol amino acids g-1 dried somatic tissuePhospholipid fatty acids: μg C-PLFA g-1 dried sample typeNeutral lipid fatty acids: μg C-NLFA g-1 dried sample type