(1) Ammonoids are descendants of the extinct, primitive coiled nautiloids and they are extinct relatives of modern squid, octopus, cuttlefish , and nautilus.(2) Nautilus shells are often used decoratively, and the internal shell of a cuttlefish , or cuttle bone, is sold in the pet trade as a calcium source for birds.(3) Both cuttlefish and squid may be called inkfish.(4) The whale's prey includes squid, cuttlefish , herring, and sea stars, or starfish.(5) Her current experiments on learning suggest that both cephalopods do well with spatial learning; cuttlefishes seem to learn their way around a maze with the same facility as octopuses.
