Rates of food uptake were measured for individually reared larvae of the spider crab Hyas araneus L. feeding on freshly hatched Artemia nauplii at constant 12 degree C. Feeding rates (FR) of crab larvae were given as number of nauplii and amounts of dry weight, carbon, nitrogen, hydrogen, and energy (estimated from C) consumed per day. In both zoeal stages FR increased during postmoult and intermoult, remained high during early and intermediate premoult, and decreased again during late premoult. No clear pattern was found in the course of daily FR of the megalopa. Gross growth efficiencies (K sub(1)) showed a dramatic decrease from postmoult to early premoult (> 60 to < 20%) in both zoeal stages. Daily consumption expressed as % body weight also decreased significantly in these instars. Average daily FR were highest in the zoea II, lowest in the megalopa, and intermediate in the zoea I. Since development of the megalopa took the longest time, the total amount of food consumed by this instar was equal to consumption in both zoeal stages combined.