jellyfish are so fascinating! Jellyfish are some of the Earth’s most ancient extant animals. Did you know that jellyfish have been around for millions of years? They’re also immensely diverse-most organisms that are called jellyfish are part of the phylum Cnidaria, which includes more than 10,000 species. This creature occur in abundant numbers all over the world, in cold and warm water, deep in the sea or near the surface.
It’s like they’re floating works of art in the water. Let learn some fact about jellyfish.
10 interesting facts about jellyfish
1. Jellyfish have an interesting way of reproducing! Jellyfish reproduction involves several different stages. In the adult, or medusa, stage of a jellyfish, they can reproduce sexually by releasing sperm and eggs into the water, forming a planula. In this larval stage of jellyfish life, the planula hooks on to the bottom of a smooth rock or other structure and grows into another stage of jellyfish life, the polyp which resembles a miniature sea anemone. During this stage, which can last for several months or years, asexual reproduction occurs. The polyps clone themselves and bud, or strobilate, into another stage of jellyfish life, called ephyra. It is this form that grows into the adult medusa jellyfish.It’s pretty amazing how they can reproduce in different ways!
2. jellyfish can live in freshwater! Although only one species of freshwater jellyfish the Craspedacusta sowerbyi or peach blossom jellyfish, originally from the Yangtze basin in China, sowerbii is an introduced species now found throughout the world in bodies of fresh water, they have a clear or translucent white bell-shaped body about the size of a dime or nickel. Unlike some marine jellyfish, the freshwater jellyfish does not pose a hazard to swimmers. They have unique adaptations that allow them to thrive in different habitats. Nature is so diverse, isn’t it?
3. Freshwater jellyfish do have predators, just like their marine counterparts. Among the predators of the jellyfish, the following have been identified: ocean sunfish, grey triggerfish, turtles especially the leatherback sea turtle, some seabirds such as the fulmars, the whale shark, some crabs such as the arrow and hermit crabs, some whales such as the humpbacks. Crayfish may also be one of the few predators that medusa stage freshwater jellyfish have.
4. Freshwater jellyfish have some defense mechanisms to protect themselves from predators. The tentacles, with their stinging cells, serve as defense and as a powerful weapon for capturing prey. When they come into contact with their victims, the nematocysts cells loaded with poison present in the tentacles release their harpoons or filaments and release a toxic substance that paralyses the prey and deliver a painful sting to potential threats. This helps deter predators and keep them safe in their watery homes the oral arms also help in the capture and ingestion of the captured animal. It’s like having their own little self-defense system!
5. Jellyfish have quite an interesting diet! Jellyfish are carnivores and can increase in size rapidly and procreate in large numbers when food is abundant. However, if food is scarce, they can become smaller. These animals, of a gelatinous consistency, have a very unsophisticated anatomy which is nevertheless very effective. They feed mainly on zooplankton, small crustaceans, and in some cases, small fish and other jellyfish also form part of their diet. It is a strange sight to see the jellyfish’s latest prey inside its body before it is digested.They use their tentacles to capture their prey and then bring it towards their mouth. It’s fascinating how they adapt to their environment and find their food!
6. Some jellyfish can live in both saltwater and freshwater environments. They have amazing adaptability that allows them to thrive in different types of water. It’s pretty cool how they can navigate between the salty ocean and freshwater habitats. Nature is full of surprises, right?
7. Some species of jellyfish are capable of undergoing a process called “transdifferentiation,” till date, there’s only one species that has been called ‘biologically immortal’: the jellyfish Turritopsis dohrnii. These small, transparent animals hang out in oceans around the world and can turn back time by reverting to an earlier stage of their life cycle, a jellyfish can also do this when it faces some kind of environmental stress, like starvation or injury, it can revert back to being a tiny blob of tissue, which then changes back into the sexually immature polyp phase of life. It is a bit like a butterfly turning back into a caterpillar, or a frog becoming a tadpole again. allowing them to potentially live indefinitely under the right conditions.
8. Despite their delicate appearance, jellyfish can be quite venomous. Their stings are fairly common problems for people swimming, wading or diving in oceans. The long tentacles trailing from the jellyfish can inject venom from thousands of microscopic barbed stingers. Most often jellyfish stings cause instant pain and inflamed marks on the skin. Some stings may cause more whole-body systemic illness. And in rare cases they’re life-threatening. Their tentacles contain specialized cells called nematocysts, which release toxins to immobilize prey.
9. Jellyfish have a unique method of propulsion called jet propulsion. They contract their bell-shaped bodies to push water behind them, propelling themselves forward. With each contraction of their body, the animals create a doughnut-shaped vortex, like a smoke ring, which they push away from themselves. The momentum of the rings creates an opposite reaction that propels the jellyfish forward, somewhat like a jet but with pulses of energy instead of a constant thrust. Although it might sound simple but the act of forming a vortex ring has proved very difficult to model mathematically.
10. Some jellyfish are bioluminescent, meaning they can produce their own light. This ability helps them attract prey and communicate with other jellyfish. This amazing ability is called “luminescence” or “bioluminescence.” Jellyfish use bioluminescence mainly to defend against predators. Comb jellies, for instance, produce bright flashes of light to startle their predators and give them time to escape. Other jellyfish can release a glowing tentacle as a decoy. Some even send thousands of glowing particles into the water to confuse their predator.
