: Hydra is almost exclusively carnivorous. Main food consists of water fleas (Daphnia) and Cyclops. Digestion in Hydra is both extracellular and intracellular. Extracellular digestion occurring in the cavity outside the gastrodermal cells and is purely proteolytic. In intracellular digestion smaller fragments of food are engulfed by nutritive muscle cells by means of pseudopodia and digested within food vacuoles. Living food is captured and paralysed by nematocysts and transferred to the mouth by tentacles.