Phytopigments and fatty acids in the gut of the deposit-feeding heart urchin Echinocardium cordatum in the southern North Sea: Selective feeding and its contribution to the benthic carbon budget

► Pigments and fatty acids were analysed in Echinocardium cordatum guts. ► Selection was relatively high, 5 to 9 for chlorophyll a and 9 to 130 for fatty acids. ► Pigments and fatty acids were transformed with an efficiency of up to 80%. ► Urchins maximise energy acquisition through high selectivity and digestive efficiency. ► The contribution of the urchins to benthic carbon budget varied from 7% to 42%.