White-patch Nautilus

The white-patch nautilus is a species of nautilus native to the Great Barrier Reef, distinguished by the absence of a thickened callus and by white patches in its umbilical and shoulder regions, with a shell that typically reaches about 180 millimeters across. It lives across Indo-Pacific coral reefs in darker waters up to 300 meters deep, moving into shallower water at night to scavenge, and uses two chemosensory rhinophores below its eyes to locate dead prey. Mature males are generally larger and more abundant than females, and genetic studies have found it closely similar to Nautilus pompilius, raising the possibility the two represent a single species.