Jellyfish are fascinating and mysterious creatures that are often seen as a scourge by fishermen but are also a source of curiosity for many people. These simple organisms are composed mainly of water and have a unique, umbrella-like bodies with various color patterns that can be quite mesmerizing.

However, jellyfish also have a powerful poisonous sting that can be deadly to humans.

One of the most interesting things about jellyfish is their low-level body structure. As coelenterates, jellyfish have no thinking ability, no blood, no ability to see things, and no bones. In fact, only 5% of their whole body is made up of organic matter. It is hard to imagine how such an inferior creature has been able to survive in the ocean for over 500 million years, longer than even the dinosaurs.

Another fascinating aspect of jellyfish is their toxicity. While being stung by an ordinary jellyfish's tentacles may only cause redness, swelling, and pain for a few days, being stung by the box-shaped jellyfish, also known as the "king of jellyfish," can be fatal. The venom from their tentacles can quickly poison and paralyze the organs of the person stung, leading to death within minutes.

Jellyfish have also been sent into space for research, and have been found to be able to live and reproduce comfortably in a low-gravity environment. However, when these small jellyfish were brought back to Earth, they all eventually died.

Despite their potentially deadly sting, jellyfish are also edible. Some types of jellyfish are considered a delicacy in certain cultures, but it is important to be careful and only eat jellyfish that are safe for consumption.

Another interesting fact about jellyfish is their unique ability to regenerate. They have the ability to regrow lost body parts, such as tentacles, and can even regenerate an entire new jellyfish from just a small piece of their body. This allows them to recover quickly from predation and other disturbances and helps to ensure their survival as a species.

In addition to their regenerative abilities, jellyfish also have a unique method of reproducing. Some species of jellyfish are capable of both sexual and asexual reproduction, meaning they can produce offspring through either fertilization or by simply dividing their body.

This allows them to adapt to different environments and reproduce quickly in order to maintain their population.

Despite their simple body structure, jellyfish also have a complex nervous system that allows them to sense and respond to their environment. They have a network of nerves called a "nerve net" that allows them to detect changes in light, temperature, and other stimuli.

This allows them to respond to predators, prey, and other environmental factors, helping them to survive in their aquatic habitat.