Jellyfish facts and photos (2024)

FAQs

What are 10 facts about jellyfish? ›

Jellyfish have tiny stinging cells in their tentacles to stun or paralyze their prey before they eat them. Inside their bell-shaped body is an opening that is its mouth. They eat and discard waste from this opening. As jellyfish squirt water from their mouths they are propelled forward.

Jellyfish are carnivores, so their diet mainly consists of other animals. This includes zooplankton, small crustaceans, small fish and other jellyfish, according to Oceana, an ocean conservation nonprofit. Jellyfish will also consume plants, National Geographic reports.

Turritopsis dohrnii: potentially immortal

Turritopsis dohrnii is called the immortal jellyfish because it can potentially live forever. Jellyfish start life as larvae before establishing themselves on the seafloor and transforming into polyps. These polyps then produce free-swimming medusas, or jellyfish.

Like any fish, the ideal conditions to keep them in will mimic their natural environment in the wild. Jellyfish live around one year to a year-and-a-half in the wild. In captivity, its usually 6 months to a year, largely because of the difficulty replicating the drifting currents and space offered by the open sea.

But they can detect light and sense their environment through the nerve net attached at the end of their tentacles.

Lacking brains, blood, or even hearts, jellyfish are pretty simple critters. They are composed of three layers: an outer layer, called the epidermis; a middle layer made of a thick, elastic, jelly-like substance called mesoglea; and an inner layer, called the gastrodermis.

Some species of jellyfish do have eyes and "teeth," or rather thin hairs that pull in and bite down on their food.

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).

Hard to think of something we share with a soft, undulating marine creature with tentacles. But we do have something in common and that is sleep. Yes, jellyfish sleep.

How are jellyfish born? ›

Throughout their lifecycle, jellyfish take on two different body forms: medusa and polyps. Polyps can reproduce asexually by budding, while medusae spawn eggs and sperm to reproduce sexually. Learn more about the lifecycle and reproduction of jellyfish.

Jellyfish don't have bones, so fossils are hard to come by. Even so, scientists have uncovered evidence these creatures have been living in our Ocean for at least 500 million years! In fact, it's likely that their lineage goes back even as far as 700 million years – possibly even longer.