Answer:
At first glance, jellyfish appear to be simple creatures. They don’t have eyes, or hearts, or even a brain. Most species simply drift in the open ocean, going wherever the current takes them.
But there’s a lot more to jellies than meets the eye. They’ve been around for at least 600 million years, making them some of the oldest creatures on the planet. They thrive in every ocean and from pole to pole. They have also adapted to live at nearly every depth in the ocean, from topside, wind-surfing species like Velella velella to bioluminescent deep sea dwellers.
