Size – Most fall within 1 to 15 inches, but some, such as the Lion’s Mane Jellyfish, can reach up to 3ft wide.
Their tentacles are “armed” with stinging cells that aid in their defense as well as dietary needs; to capture prey. Their transparent, bell-shaped body is made up of a matter known as mesoglea.
They can be found all over the world. Nearly every species is marine, but there are a few freshwater species. There is even a marine lake called “Jellyfish Lake,” where millions of Golden Jellyfish migrate daily. Most live away from the seafloor and can be found living, floating, freely as a part of plankton.
They are generally carnivorous and can be found feeding on plankton, crustaceans, small fish, and even other sea jellies. They feed by using their tentacles to stun their prey, sometimes done passively, and then they ingest food and discard the waste from their mouth.
They come in many sizes and colors, and often travel in groups called “smacks.” Many swimmers are stung each year, with Box Jellyfish actually being responsible for some fatal stings.
They would never seek out and prey on a human, but when they travel in large groups, and a swimmer gets too close, it can be hard to avoid a tentacle.
Jellyfish or Sea Jelly is the name given to certain jelly-like members of the subphylum called Medusozoa, the major section of the Phylum called Cnidaria. This name is given due to their appearance during their medusa-phase.
The four major classes of Medusozoan Cnidaria are:
- Scyphozoa (true jellyfish) – 200+ Species
- Cubozoa (box jellyfish) – Around 20 Species
- Hydrozoa – 1000+ Species
- Staurozoa (stalked jellyfish) – Around 50 Species