Glossary

tentacle

Slender, elongate, flexible, unsegmented, usually tactile or prehensile, process extending from the body in certain organisms.

Used in 8 species profiles

cephalopod
Any marine mollusc of the class Cephalopoda which includes octopus, squid, cuttlefish, and nautilus. Characterised by possession of a large head and eyes, prehensile tentacles, and, in most species, a specialised sac containing a dark, inky fluid used in defensive behaviour.
decapod
Any member of the crustacean order Decapoda, comprising species possessing 5 pairs of jointed, thorassic limbs such as crabs, crayfish, lobsters and shrimp. Also used historically in reference to molluscs of the Cephalopod superorder Decapodiformes, members of which have 8 short limbs plus 2 longer tentacles and include cuttlefish and squid.
Gastropoda
Class of molluscs of which the majority of members possess a flattened, muscular foot for locomotion and a head bearing specialised sensory tentacles, with some also having a univalve, coiled shell. Includes all snails, whelks, limpets, conches, and slugs.
Hydra
Genus of freshwater cnidarian existing only in sessile, solitary polyp form attached to the substrate at one end and with a mouth surrounded by up to 12 tentacles at the other. Members are predatory, feeding mostly on small invertebrates, and regarded as pests in aquaria due to their appearance as whitish spots on submerged surfaces and tendency to prey on fish fry.
polyp
One of two types of body form occurring in coelenterates, comprising a hollow cylindrical body with a ring of tentacles around the mouth.
prehensile
Able to grasp or hold.
tactile
Of or relating to touch.