tentacle
Quick Summary
A tentacle is an invertebrate anatomical feature. Tentacles vary greatly in number and function across different species. For example, jellyfish can have anywhere from 8 to over 1,200 tentacles, which are equipped with stinging cells to capture prey. Beard worms possess feather-like tentacles at their anterior end, which they use for filter-feeding, drawing in microorganisms and nutrients from the water. Cephalopods, such as squids and octopuses, have arms and tentacles that surround their heads, used for locomotion, capturing prey, and sensing their environment.123
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
chemoreceptionSpecialized chemosensory structures…sensilla are often borne on tentacles.
Read More…sensilla are often borne on tentacles.
Read More- chemoreceptionTerrestrial vertebrates
…to the vomeronasal organs via tentacles. Directly in front of each eye is a small pore leading to a sac that contains a tentacle. The tentacle can be extended through the pore by hydrostatic pressure to make contact with the surrounding soil. A duct connects the tentacular sac with the…
Read More…to the vomeronasal organs via tentacles. Directly in front of each eye is a small pore leading to a sac that contains a tentacle. The tentacle can be extended through the pore by hydrostatic pressure to make contact with the surrounding soil. A duct connects the tentacular sac with the…
Read More
beard wormNatural historyThe tentacles, probably used during feeding, vary in number according to body size. The tentacles are long processes containing blood vessels and are continuous with the body cavity, or coelom. Rows of very thin single-celled units called pinnules are found on the tentacles. The pinnules, which…
Read MoreThe tentacles, probably used during feeding, vary in number according to body size. The tentacles are long processes containing blood vessels and are continuous with the body cavity, or coelom. Rows of very thin single-celled units called pinnules are found on the tentacles. The pinnules, which…
Read More- bivalveThe nervous system and organs of sensation
…mantle margins and typically comprise tentacles developed from the middle mantle folds that are mechanoreceptors and chemoreceptors. Scallops (family Pectinidae) have complex eyes with a lens and retina. In other bivalves, eyes are simple ciliated cups, although some variation is possible. In the predatory deepwater septibranchs the inhalant siphon, which…
Read More…mantle margins and typically comprise tentacles developed from the middle mantle folds that are mechanoreceptors and chemoreceptors. Scallops (family Pectinidae) have complex eyes with a lens and retina. In other bivalves, eyes are simple ciliated cups, although some variation is possible. In the predatory deepwater septibranchs the inhalant siphon, which…
Read More 
cephalopodGeneral features and importance to humans…the possession of arms and tentacles, eight or 10 in most forms but about 90 in Nautilus. Except for the nautilus, all living members of the class show great modification and reduction of the characteristic molluscan shell.
Read More…the possession of arms and tentacles, eight or 10 in most forms but about 90 in Nautilus. Except for the nautilus, all living members of the class show great modification and reduction of the characteristic molluscan shell.
Read More- cephalopodDistinguishing taxonomic features
…or absence of an eyelid, tentacles retractile or contractile or both, shape and size of fins, number of arms, number of sucker rows, presence or absence of teeth and hooks on arm and tentacular suckers, radular dentition, structure of funnel organ, spermatophores, details of the hectocotyles, number of gill lamellae,…
Read More…or absence of an eyelid, tentacles retractile or contractile or both, shape and size of fins, number of arms, number of sucker rows, presence or absence of teeth and hooks on arm and tentacular suckers, radular dentition, structure of funnel organ, spermatophores, details of the hectocotyles, number of gill lamellae,…
Read More 
cnidarianSize range and diversity of structure…bell or an umbrella, with tentacles hanging downward at the margin. The tubelike manubrium hangs from the centre of the bell, connecting the mouth at the lower end of the manubrium to the coelenteron within the bell. Most medusae are slow-swimming, planktonic animals. In contrast, the mouth and surrounding tentacles…
Read More…bell or an umbrella, with tentacles hanging downward at the margin. The tubelike manubrium hangs from the centre of the bell, connecting the mouth at the lower end of the manubrium to the coelenteron within the bell. Most medusae are slow-swimming, planktonic animals. In contrast, the mouth and surrounding tentacles…
Read More
ctenophoreForm and function.…pair of long, retractable branched tentacles that function in the capture of food. The tentacles are richly supplied with adhesive cells called colloblasts, which are found only among ctenophores. These cells produce a sticky secretion, to which prey organisms adhere on contact.
Read More…pair of long, retractable branched tentacles that function in the capture of food. The tentacles are richly supplied with adhesive cells called colloblasts, which are found only among ctenophores. These cells produce a sticky secretion, to which prey organisms adhere on contact.
Read More
gastropodThe head…one or two pairs of tentacles, often with accessory palps, and the mouth in the middle of the ventral margin. In stylommatophoran land snails the upper tentacles, or ommatophores, are invaginable (capable of being rolled in), and the eyes are borne at the tips. In freshwater basommatophorans and most prosobranchs…
Read More…one or two pairs of tentacles, often with accessory palps, and the mouth in the middle of the ventral margin. In stylommatophoran land snails the upper tentacles, or ommatophores, are invaginable (capable of being rolled in), and the eyes are borne at the tips. In freshwater basommatophorans and most prosobranchs…
Read More
octopusDescription…complex eyes and eight contractile arms. Each arm bears two rows of fleshy suckers that are capable of great holding power. The arms are joined at their bases by a web of tissue known as the skirt, at the centre of which lies the mouth. The latter organ has a…
Read More…complex eyes and eight contractile arms. Each arm bears two rows of fleshy suckers that are capable of great holding power. The arms are joined at their bases by a web of tissue known as the skirt, at the centre of which lies the mouth. The latter organ has a…
Read More
protozoanMechanisms of food ingestion…ciliate predators that usually possess tentacles of two functional types: feeding tentacles and piercing tentacles. The latter trap and immobilize the prey, usually other ciliates that make chance contact with the outstretched tentacles of the suctorian. The cell contents of the prey are transported up through the feeding tentacles into…
Read More…ciliate predators that usually possess tentacles of two functional types: feeding tentacles and piercing tentacles. The latter trap and immobilize the prey, usually other ciliates that make chance contact with the outstretched tentacles of the suctorian. The cell contents of the prey are transported up through the feeding tentacles into…
Read More