Animals That Don’t Have Brain
Sea Urchins Sea urchins are pointy, spiky animals, and any beachcomber in their bare feet might discover this in the worst way.The creature has an untold number of legs and controls feeding with its water vascular system.
Sea Cucumbers The wormlike sea cucumber feeds on plankton, and the leathery-skinned animals are everywhere. Sea cucumbers are extremely dangerous but, without a brain, they’re not necessarily a deliberate threat. They are capable of releasing a toxic substance called holothurin, which can blind humans permanently.
Jellyfish Called “jellies,” this family of translucent creatures is unique. All other creatures without brains tend to be immobile, often spending their entire existence in a single spot. Jellyfish move with the ocean current. They also squirt water that can move them forward.
Corals The coral and jellyfish are part of the Cnidarians family. Their bodies are asymmetric and they both sting their enemies. Categorized as plants, coral is actually a living animal without a brain.
Starfish The starfish is a cousin of the sea urchin. But — wait for it! — it’s not a fish. The truth is this species can’t swim. Starfish spend all their time at the bottom of the ocean. Though you can find them floating or washed ashore, that’s never by choice!
Clams Clams are bivalves, which is a mollusk with compressed bodies inside of a pair of hinged shells. Others in the family include oysters, mussels, clams, and scallops. Clams can open and close their shells.
Man-O-War Another wobbly-like critter with a venomous sting, the Portuguese man-o-war is up there on the list of strangest animals on the planet. While we refer to the creature in the singular, we should actually say “man-o-wars.” You see, the animal is actually a colony of polyps, also referred to as zooids. Connected by tissue, the colony cannot survive individually.
Sea Sponges Among the animal kingdom’s most primitive animals, the sea sponge stays relatively immobile. It’s the water that moves them around and makes them look like they’re dancing. Their survival centers around filtering detritus from the ocean. They have no brains, organs, neurons, or tissue.
Oysters Relative to the clam, the oyster is infamous for enclosing precious pearls in its shell. But it’s a treasure hunt since your odds of finding a perfect pearl are roughly one in a million. Oysters filter water and remove organic particles — like plankton — to eat them. They can filter up to 50 gallons of water per day, giving them enough food to last a while.
Sea Lillies Sea lilies resemble plants with feathery limbs. They sit immobile at the bottom of the ocean for their entire lives. There’s also research that shows the sea lily is capable of floating to a new spot when it can no longer find food. If needed, they can move along at up to 140 miles an hour.
Sea Squirts Get ready for the weirdest creature on this list. To start, the sea squirt is both male and female. As a hermaphrodite, it has both sexual reproductive organs — the creature does not need a mate to have children. Their tadpole larvae result from sperm and eggs that come from a single animal.
Sea Anemones The sea anemone is yet another animal that has a plant-like appearance. However, the sea anemone is very much alive and seeking food, which it uses its long tentacles to catch and eat.