Jellyfish are not a fish, in fact they don’t look like fish. They are invertebrates. They’re part of a diverse team of gelatinous zooplankton, zooplankton being animals that drift in the ocean. They have an umbrella shaped bell. Under the bell are tentacles. Jellyfish can be very colorful. The bell can be transparent. Jellyfish have three layers; the outer layer is called epidermis. The middle layer is made of a thick elastic jelly-like substance called mesoglea. The inner part is called gastrodermis. The tentacles have little stinging fibers, so when you touch it, the stinging fiber will dart out and inject poison.
There are a lot of types of species. Such as: Box jellyfish, Lion’s mane jellyfish, Pacific sea nettle jellyfish, Moon jellyfish, and Upside-down jellyfish. There are over 1,000 species of jellyfish. Scientists believe that there may be 300,000 species of jellyfish that we haven’t yet discovered.
Fun facts:
- The lion’s mane jellyfish is the longest jellyfish.
- The box jellyfish has the most venomous marine animal in the world.
- A ten-year-old girl was the first person to survive a box jellyfish sting.
- If you cut the jellyfish in half, the pieces of the jellyfish can regenerate and turn into two new jellyfish
- Jellyfish can clone themselves.
If you get stung by jellyfish and you want to heal it, then put vinegar and clean water on the sting. Use tweezers and remove any tentacles that are still on your skin. Do not put an ice pack or ice. Call a doctor.
Jellyfish eat lots of kinds of food such as fish, shrimp, crabs, fish eggs, crustaceans, and tiny plants. The mouth is on the underside of its bell. The nutrients are absorbed by an inner layer of cells.
Jellyfish have predators such as sea turtles and sunfish.
Jellyfish don’t have a brain or a heart but they have a neural net around the bell inner margin that forms a rudimentary nervous system that can sense the ocean’s current and the touch of other animals. Cells called nematocysts are the little cells on the tentacles that sting. When the nematocysts are triggered by contact, they shoot with an explosive force.
Jellyfish live for at least 500 million years, and maybe go back to 700 hundred years. Like most animals, jellyfish life begins as a larva egg. It attaches to the seafloor and becomes a polyp. Soon it buds and makes a young medusa. Soon it grows up to be a medusa. There is an immortal jellyfish, but it can die. When the immortal jellyfish feels sick, instead of dying it can reverse its life cycle.