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.
Below is a photo of another nautilus shell. It has the same general pattern in that its spiral curve conforms fairly closely to a full rotation golden ratio spiral expansion for the first three rotations, but this one has a tighter curve than the golden ratio spiral in its final outward spiral.he Nautilus spiral is definitely not at all like the 90 degree spiral created with a golden rectangle. Itâs closer to a spiral that expands by phi every 180 degrees, but thatâs still not really a fit either.