This is the Pelagia noctiluca jellyfish. This species of jellyfish is the most common stinger in the Mediterranean Sea. Its sting is very painful and leaves scars on the skin.
This coral has secreted a calcium carbonate hard skeleton for protection and support. Individual heads grow by the asexual reproduction of polyps. Coral also breed sexually by spawning. Polyps of the same species release gametes simultaneously over a period of one to several nights around a full moon.
This is a hydra in the midst of asexually reproduction. The bud on the side of the hydra will develop into a new organism and will separate from the hydra when it is mature.
This is a sea anemone. When their prey touches their tentacles, it injects a paralyzing neurotoxin. The prey is then guided into their mouth in the center of their bodies by their tentacles.
Sea anemones in a coral reef. They come in many colors!