How Upside-Down Jellies Sting You Without Touching You

The Upside Down Jelly, Cassiopeia zamachana, is a unique jellyfish that lives in coastal waters. It uses its bell to anchor itself upside down and has a symbiotic relationship with algae, which provide it with food. The jellyfish can sting without contact by releasing cassiosomes, tiny structures filled with stinging cells, into the water. These cassiosomes can survive for days, explaining reports of stinging water. The discovery of cassiosomes in 2016 revealed their role as a long-range weapon, enhancing the jelly's feeding strategy and evolutionary success.

What unique behavior does the Upside Down Jelly exhibit?

• It rests upside down on the sea floor.

• It swims in circles.

• It changes color frequently.

• It jumps out of the water.

What is the role of the algae living in the tentacles of the Upside Down Jelly?

• They clean the jelly's tentacles.

• They produce food for the jelly.

• They provide camouflage.

• They help the jelly move.

What did researchers discover about the mucus released by the Upside Down Jelly?

• It is used for communication.

• It contains tiny structures called cassiosomes.

• It helps the jelly to float.

• It attracts other jellies.

How do cassiosomes benefit the Upside Down Jelly?

• They provide nutrients to the jelly.

• They act as a long-range weapon to capture prey.

• They help the jelly to swim faster.

• They allow the jelly to change color.

What evolutionary advantage do cassiosomes provide to the jelly's relatives?

• They help the jellies to reproduce faster.

• They enable the jellies to live in colder waters.

• They allow the jellies to grow larger.

• They give the jellies extra firepower for survival.