Are sessile, have tentacles, mouths open downwards
Explanation:
Medusae may have many tentacles with which they catch their prey. Sometimes, people bathing in the ocean are touched by a medusa. Their tentacles are long and thin and covered in venomous stinging cells (known as nematocysts). They inject poison which immobilizes small fish. People who are stung should seek medical attention. There have been some deaths after severe medusa stings.
