Corals use the tentacles which surround their mouth to catch and eat tiny zooplankton. They feed, by filter-feeding, only at night but this might be because this is when the zooplankton are available.

Jellyfish eat small animals such as shrimp and plankton but some of the creatures they eat are microscopic and too small to be seen by the naked eye. They catch their prey by using nematocysts and some of the stings paralyze their prey. Jellyfish usually wait for prey to swim or drft into their tentacles.

Sea anemones look like beautiful flowers but in fact, they are meat-eating creatures. They will wait for their prey to swim by and then they sting it and push it into their mouth.