Jellyfish Facts

Jellyfish facts can be fascinating. They are among the most plentiful creatures in the oceans, and are also quite varied. While some pack a painful sting, the majority are harmless to humans. Among the most fascinating jellyfish facts:

1. There are about 200 known species of jellyfish. They range in size from tiny, like the finger-nail sized Irukandji jellyfish to giant, like the Portuguese Man of War, which can have tentacles up to 50 meters in length. Of the 200 known species, 70 are known to sting.
2. Jellyfish can now be kept in home aquariums. Until recently, there were no suitable home aquarium set ups. Existing tanks had too many sharp angles for the delicate jellyfish. However, new specialty tanks come in rounded shapes and use filtration systems that will not hurt them.
3. Jellyfish have begun showing up in swarms in many coastal areas. As many species of fish become depleted, jellyfish are moving into their niche. Once jellyfish are established in an area, they also begin eating many fish species' fries, which leads to a situation where jellyfish become even more prevalent while finned fish are further depleted.
4. You can eat jellyfish. They are a popular dish in many Asian cuisines. Common recipes include salads and soups.
5. Jellyfish are closely related to sea anemones, coral, sea whips and hydroids. They are all part of the phylum Cnidaria.
6. Jellyfish do not have brains. Instead, they have what is known as a nerve net. These nerves allow them to perceive light, scents and other stimuli.