How to live without a heart or a brain - Lessons from a Jellyfish

Jellyfish are ancient creatures related to coral and sea anemones, dating back 500 million years. Despite lacking a brain and heart, they thrive in various environments. Their nerve net allows them to sense and respond to their surroundings. Some jellyfish have advanced sensory structures like ropalia and eyespots. They absorb oxygen through their ectoderm and store it in the mesoglia, allowing survival in low-oxygen waters. Their simple digestive system breaks down food in the gastrovascular cavity. Jellyfish complexity offers insights into the evolution of nervous systems.

How do jellyfish exhibit behaviors like courtship without a brain?

What is the significance of the jellyfish's mesoglia?

What types of food do jellyfish consume?