You will receive a sample of both green and brown hydra mixed together, allowing you to observe the differences between the two organisms.

Hydra are tiny animals closely related to jellyfish. They can be found in freshwater river and streams where they attach themselves to plants and rocks.

Hydra have a sack-shaped body with a ring of tentacles around the mouth at the top. They use those tentacles, covered with paralyzing nematocysts, to trap small cruscaceans, stun them and bring them into the mouth where they are digested.