Introduction to jellyfish: As an animal, jellyfish has no brain or heart. It has reproduced on the earth for 650 million years and is a kind of aquatic creature with strong survival ability. The jellyfish on display in the aquarium have their own characteristics, and are named Pacific sea nettle jellyfish, Papua jellyfish, moon jellyfish, Japanese sea nettle jellyfish and colorful jellyfish. Some of their "swimming postures" are elegant, some are colorful, and some have been processed by ancient people into "hidden weapons" to irritate the enemy's eyes.