<P> Among cephalopods, squid have spectacular tentacles . They take the form of highly mobile muscular hydrostats with various appendages such as suction disks and sometimes thorny hooks . Up to the early twentieth century "tentacles" were interchangeably called "arms". The modern convention however, is to speak of appendages as "tentacles" when they have relatively thin "peduncles" or "stalks" with "clubs" at their tips . In contrast the convention refers to the relatively shorter appendages as "arms". By this definition the eight appendages of octopuses, though quite long, count as arms . In terms of this article however, both types of organs count as tentacles because in relevant ways they are structurally and functionally similar . </P> <P> The tentacles of the giant squid and colossal squid have powerful suckers and pointed teeth at the ends . The teeth of the giant squid resemble bottle caps and function like tiny hole saws, while the tentacles of the colossal squid wield two long rows of swiveling, tri-pointed hooks . </P> <P> Cnidarians, such as jellyfish, sea anemones, Hydra and coral have numerous hair - like tentacles . Cnidarians have huge numbers of cnidocytes on their tentacles . In medusoid form, the body floats on water so that the tentacles hang down in a ring around the mouth . In polyp form, such as sea anemone and coral, the body is below with the tentacles pointed upwards . Many species of the jellyfish - like ctenophores have two tentacles, while some have none . Their tentacles have adhesive structures called colloblasts or lasso cells . The colloblasts burst open when prey comes in contact with the tentacle, releasing sticky threads that secure the food . </P> <P> The tentacles of the Lion's mane jellyfish may be up to 120 feet (37 meters) long . They are hollow and are arranged in 8 groups of between 70 and 150 . The longer tentacles are equipped with cnidocytes whose venom paralyses and kills prey . The smaller tentacles guide food into the mouth . </P>

What capture their prey with a ring of stinging tentacles