CHAMBERED or EMPEROR NAUTILUS (Nautilus pompilius) © Michele Hall
A Chambered Nautilus skitters into deep water at Osprey Reef in Australia’s Coral Sea during the filming of the IMAX® film Under the Sea.
The Chambered Nautilus, is the best-known and one of the largest species of nautilus, the largest recorded was nearly 11” on diameter. The shell, when cut away reveals a lining of lustrous nacre and displays a nearly perfect equiangular spiral. The shell exhibits countershading, being light on the bottom and dark on top. This is to help avoid predators because when seen from above, it blends in with the darkness of the sea, and when seen from below, it blends in with the light coming from above.
They live from the Andaman Sea east to Fiji and southern Japan south to the Great Barrier Reef.
The chambered nautilus has more primitive eyes than some other cephalopods; the eye has no lens and thus is comparable to a pinhole camera. The species has about 90 tentacles with no suckers, which is also different from other cephalopods. Chambered nautiluses have a pair of rhinophores, which detect chemicals, and use olfaction and chemotaxis in order to find their food (Shrimp, small fish and crustaceans).
Fact Source: http://en.wikipedia.org/wiki/Chambered_Nautilus
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