How does a hydra respond to stimuli in its environment?
All animals have body systems that allow them to sense and respond to changes in their environment. These systems help them find food, escape from predators, and locate a mate. Most animals have some type of nervous system. In general, certain nerve cells are specialized to sense stimuli and others are specialized to coordinate a response. For instance, sensory nerve cells might detect a temperature drop, and motor neurons may coordinate the animal’s move to a warmer area.
Hydras are small aquatic animals that are closely related to jellyfish, coral, and sea anemones. They feed on tiny animals, plants, and microorganisms. In a hydra, the nerve cells form a nerve net, which is much simpler than the complex nervous system of a human. A hydra does have some cells that are specialized for the detection of touch and chemicals.
In this lab, you will observe the anatomy of a hydra, and how the hydra responds when it senses nearby prey.