náutilo

Nautilus is a genus of marine cephalopods in the family Nautilidae. They are the sole surviving family of the subclass Nautiloida, which was once a diverse group of marine mollusks. Nautiluses are distinguished by their external shell, which is typically coiled in a flat spiral. The shell is divided into chambers, with the animal living in the outermost chamber. The chambers are filled with gas, which the nautilus controls to regulate its buoyancy, allowing it to ascend or descend in the water column.

There are currently six recognized species of nautilus, all belonging to the genus Nautilus. These species are found in the tropical Indo-Pacific region. They are primarily nocturnal, spending their days in deeper waters and ascending to shallower areas at night to feed. Their diet consists mainly of crustaceans and small fish. Nautiluses have a relatively slow metabolism and can survive for extended periods without food.

The external shell of the nautilus has been a source of fascination for centuries, often referred to as a "living fossil" due to its ancient lineage. The shell's intricate structure and the animal's unique life cycle have made it a subject of scientific study and popular interest. Despite their ancient origins, nautiluses face threats from habitat degradation and overfishing, which have led to declining populations for some species. Conservation efforts are underway to protect these remarkable creatures and their marine environments.