Tentacle

A tentacle is a special, bendable part found in many animals, especially those without a backbone, called invertebrates. These long, moving parts help animals catch food and feel their way around. Tentacles work like strong, flexible tubes made of muscle, known as muscular hydrostats.

Many animals use their tentacles to sense things like touch, see, or even smell food and danger. For example, some snails have special tentacle-like structures called eyestalks on their heads. Tentacles are different from another animal part called a cirrus, which is usually weaker and less flexible. Animals like nautilus have cirri, while squid have true tentacles, showing how these amazing body parts help different creatures survive.

Invertebrates

Many molluscs, like land snails, have tentacles on their heads. These tentacles can stretch out and have eyes on the tips of some pairs. They also have special tentacles near their mouths to hold food before eating. Marine snails, such as abalone and top snails, have many small tentacles around their edges.

Cephalopods, including squids and octopuses, have impressive tentacles. Squids use theirs to catch prey with suction disks or hooks. Octopuses have eight arms, which are also a type of tentacle, to grab and manipulate objects. Cnidarians, like jellyfish and sea anemones, have many tiny, hair-like tentacles that help them catch food. These tentacles can sting and paralyze their prey. Other animals, such as bryozoa, use their tentacles to filter food from the water.

Vertebrates

Some animals that have backbones, called vertebrates, also have tentacles. Caecilians, a type of legless amphibian, have two short tentacles on each side of their heads. These tentacles help them smell, navigate, and find food underground.

The star-nosed mole, found in North America, has 22 tiny tentacles around its nose. These tentacles are very sensitive and help the mole feel its way through tunnels and find food. They are very small, only about 1–4 mm long, and have special touch receptors that make this mole very good at feeling things.

Main article: Amphibians

Main article: Star-nosed mole

Tentillum

The word tentillum (plural: tentilla) means "little tentacle." It usually refers to a small side branch coming off a larger tentacle. These tiny branches can have special jobs. For example, in animals called Cnidaria, tentilla often carry tiny cells named cnidocytes, while in animals called Ctenophora, they usually have cells called collocytes. One group of Cnidaria, the Siphonophores, uses tentilla to help them catch food.