Nutrition: The biochemical process in which complex food is converted into simple and soluble food and the undigested part is excreted is called nutrition. Nutrients absorbed by the body replenish, grow and produce energy.
Foraging techniques
Hungry hydra grips the base with the soles and floats the body and gills to catch prey. The nematocysts of the attractor are activated when prey approaches. Different types of nematocysts are ejected as the prey touches the attractor.
Volute nematocyst inhibits prey movement. Glutinants trap prey by secreting sticky juices. The stenotil nematocyst injects a poison called hypnotoxin into the victim’s body and paralyzes the victim. Then the food is brought to the mouth. The stomata are swollen and wide and food enters the mouth. Mucus secreted from glandular cells makes food moist and slippery. As a result of contraction and expansion of the hypostome and body wall, food enters the cilantro.