A specialize cell unique to the phylum Cnidaria. It contains a capsule-like organelle housing a coiled thread that, when discharged, explodes outward and functions in prey capture or defense.
The unique cephalopod mollusks can be found in the Indian and Pacific Oceans, living in rock crevices and coral reefs. Several characteristics make the nautilus stand out from other mollusks and marine animals. Unlike other mollusks, the nautilus has a hard external shell, which takes the form of a spiral.As the animal grows, it seals off chambers in the shell which fill with gas, making the shell buoyant so that the nautilus can swim.he beauty of the nautilus shell has inspired many beach-oriented establishments or brands to name themselves after it. One example is the Nautical Hotel in Santa Teresa, Costa Rica. Though the design of the hotel itself bears no resemblance to the nautilus shell, the name conveys a sense of paradise.
This term is now often applied to both the Cnidaria and the Ctenophora together, based on the fact that species belonging to these two phyla have radial or biradial symmetry. Some of the other common characteristics of the Cnidaria phylum include: 1.All species belonging to this phylum have bodies that have radial symmetry. This means that they are the same shape from every side and that the whole jellyfish body is around a central axis. 2.ne of the more interesting characteristics of the species of this phylum is the fact that they exist in two different body forms. They are a polyp or a medusa at different times in their life cycle. The reproductive cycle of the members of this phylum is also distinctive.