Characteristics of Nautilus:
1. Shell: The most distinctive feature of nautiluses is their external spiral shell, which is divided into chambers. As the nautilus grows, it adds new chambers to its shell, and the older ones are sealed off.
2. Siphuncle: Nautilus shells have a hollow tube called the siphuncle that runs through all the chambers. The siphuncle helps in controlling the buoyancy of the nautilus by regulating the flow of gas and liquid within the chambers.
3. Tentacles: Nautiluses have multiple arms or tentacles that surround the head. These tentacles have adhesive discs used to grasp objects and move along the ocean floor.
4. Eyes: Nautiluses have highly advanced eyes for their group, known as cephalopods. They possess camera-like eyes with lenses and a pupil, enabling them to see and perceive their environment.
5. Reproduction: Nautilus reproduces sexually, and males have specialized tentacles adapted for transferring sperm to the female. Female nautiluses lay eggs in sheltered locations, and the embryos develop inside protective shells until hatching.
6. Habitat: Nautiluses are marine creatures and are found in various regions of the Indo-Pacific Ocean. They typically inhabit deep waters, ranging from depths of around 100 to 1000 meters.
7. Feeding: Nautiluses are carnivores and primarily feed on small organisms, such as planktonic animals, and the remains of dead animals. They use their tentacles to capture and manipulate prey.
Nautiluses are fascinating creatures and hold an important place in scientific and ecological research. They are among the oldest living marine animals and serve as a link between ancient and modern cephalopods. As such, they provide insights into the evolutionary history and diversity of these organisms.
The chambered nautilus is considered a living fossil due to its primitive characteristics that have remained relatively unchanged for millions of years.