The 'immortal' jellyfish, Turritopsis dohrnii To date, there's only one species that has been called '
Regenerating flatworms
This apparently limitless regeneration also applies to aging and damaged tissue, allowing the worms to cheat death indefinitely, according to a study at the University of Nottingham.
Jellyfish belong to a group called Cnidaria, which also includes sea anemones and corals. As animals, they are subject to the cycle of life and death - though one species is known to bend the rules.
They found that, on average, male European lobsters live to 31 years old, and females to 54. There were a few exceptions: one female had reached 72 years old. Lobsters certainly do not live forever. It's not entirely clear where this myth originated, but it is a claim that persists online, often in the form of memes.
They shed their limbs, become a drifting blob and morph into polyps, twiggy growths that attach to rocks or plants. Gradually, the medusa buds off the polyp once again, rejuvenated. While a predator or an injury can kill T. dohrnii, old age does not.
The 'immortal' jellyfish, Turritopsis dohrnii
To 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.
The good news is that you can be immortal. The bad news is that you have to become a floating blob of jelly to do so. Scientists have discovered a jellyfish which can live forever. The Immortal Jellyfish known scientifically as Turritopsis dohrnii is now officially known as the only immortal creature.
Thus, crabs pass the bar scientists set for showing that an animal feels pain.
Research has clearly shown that lobsters, crabs, and other crustaceans can and do experience pain. Scientists have shown that their reaction to painful stimuli is more than just a reflex response and instead, they learn from painful stimuli and change their behavior.
While, as shown with creatures such as hydra and Planarian worms, it is indeed possible for a creature to be biologically immortal, these are animals which are physiologically very different from humans, and it is not known if something comparable will ever be possible for humans.
Never touch a jellyfish that's washed up on shore. Dead jellyfish still have venom in their tentacles that can sting on contact.
Even if the jellyfish is dead, it can still sting you because the cell structure of nematocysts is maintained long after death. Nematocysts release a thread that contains the venom when a foreign object brushes against the cell and will continue releasing venom until the cells are removed.
The moon jelly differs from many jellyfish in that they lack long, potent stinging tentacles. Instead they have hundreds of short, fine tentacles that line the bell margin. The moon jelly's sting is mild and most people have only a slight reaction to it if anything at all.
Snails have more teeth than any animal.
This is TRUE. A snail's mouth is no larger than the head of a pin, but can have over 25,000 teeth (but these aren't like regular teeth, they are on its tongue).
Did anyone know that some animals have blue blood, especially when it is exposed to oxygen? Can you guess what animals might have blue blood? Lobsters, crabs, pillbugs, shrimp, octopus, crayfish, scallops, barnacles, snails, small worms (except earthworms), clams, squid, slugs, mussels, horseshoe crabs, most spiders.
Flatworms, nematodes, and cnidarians (jellyfish, sea anemones, and corals) do not have a circulatory system and thus do not have blood. Their body cavity has no lining or fluid within it.
A favored method of preparing fresh crabs is to simply boil them alive. A longstanding related question: Do they feel pain? Yes, researchers now say. Not only do crabs suffer pain, a new study found, but they retain a memory of it (assuming they aren't already dead on your dinner plate).
While mammals and birds possess the prerequisite neural architecture for phenomenal consciousness, it is concluded that fish lack these essential characteristics and hence do not feel pain.
Given that plants do not have pain receptors, nerves, or a brain, they do not feel pain as we members of the animal kingdom understand it. Uprooting a carrot or trimming a hedge is not a form of botanical torture, and you can bite into that apple without worry.
It is likely to lack key features such as 'distress', 'sadness', and other states that require the synthesis of emotion, memory and cognition. In other words, insects are unlikely to feel pain as we understand it.
They might sense something, but it is not painful and does not compromise their well-being."
The wild wriggling and squirming fish do when they're hooked and pulled from the water during catch-and-release fishing isn't just an automatic response—it's a conscious reaction to the pain they feel when a hook pierces their lips, jaws, or body.
When the medusa the immortal jellyfish (Turritopsis dohrnii) dies, it sinks to the ocean floor and begins to decay. Amazingly, its cells then reaggregate, not into a new medusa, but into polyps, and from these polyps emerge new jellyfish. The jellyfish has skipped to an earlier life stage to begin again.
Of those that do exist, the oldest-known jellyfish fossils, found in Utah, date to 505 million years ago and have enough detail to show clear relationships with some modern species of jellyfish.