The+Chambered+Nautilus

====The Chambered Nautilus, also a common name for the nautilus species are often considered to be living fossils. The Chamber Nautilus is the largest among its species and it is the most common one out of the six species known that are known to exist today. The Chambered Nautilus is one of those animals that have remained unchanged for over 400 million years. During the prehistoric era, there were approximately 10,000 species of nautilus, however only a small portion of the populationremains. The Chambered Nautilus belongs to the Cephalopoda class. The Chambered Nautilus is closely related to other Cephalopods such as squid, cuttlefish and octopus.==== ====The Chambered Nautilus grows to 8-10 inches in size when fully grown. Inside the shell, it is divided into chambers. As the nautilus matures, it creates new chambers that are larger than the one before allowing the more space for it’s growing body. The Chambered Nautilus has 4 chambers at the moment of hatching and increase to over thirty in adults.====
 * **Nautilus ****Temporal range: Triassic–Present **[|[1]] ||
 * [[image:220px-Nautilus_profile.jpg align="center"]] ||
 * [|//Nautilus belauensis//] ||
 * [|**Scientific classification**] ||
 * Kingdom: || [|Animalia] ||
 * Phylum: || [|Mollusca] ||
 * Class: || [|Cephalopoda] ||
 * Subclass: || [|Nautiloidea] ||
 * Order: || [|Nautilida] ||
 * Superfamily: || [|Nautilaceae] ||
 * Family: || **<span style="font-family: 'Helvetica','sans-serif'; font-size: 17px;">Nautili ** ||

=King Clang (Future Animal)= =Ammonite (Ancestors)= = = = =

= **Adaptations** =

**//Structural: Outer Shell//**


 * [[image:chambered-nautilus-shell-se40.jpg width="139" height="110" align="left"]]

The Chambered Nautilus can withdraw itself into all these chambers when being attacked. || ====Nautilus is one of those animals, which have a shell outside its soft body. The shell of each individual nautilus is comprised of many chambers. The shell is coiled, aragonite, nacreous and pressure resistant,therefore it can protect the nautilus from water pressure to a depth of 800 meters. The strong allows nautilus to swim deeper into water and protects it from predators such as sharks. The colors on the shells keep the animal camouflage in water. When the shell is seen from above, the shell will appear to be darker, which helps the nautilus blend into darker colors below. Respectively, the bottom of the shell is completely white, which makes the animal indistinguishable from brighter waters above.==== ====**Environmental pressure:** They have been adapted this way because their pass ancestors did not have any protection against predators or water pressures therefore a shell grows to provide more survivability.==== .

**//Structural: Tentacles//** As seen above, the tentacles provide a powerful grip of its prey. The tentacles are the only way of capturing a prey, without it, it would be impossible for it to capture any prey before it escapes. ||
 * [[image:Nautilus_tentacles.jpg width="229" height="139" align="center"]]

====The Nautilus has much more tentacles than its close cousins. Depending on its species, a nautilus can have up to 90 tentacles. The tentacles are mainly used to capture prey, however it is also used for touch and taste. Unlike other Cephalopoda, the tentacles do not contain suction caps. Due to the fact that they don't have suction caps, they have folds and crease which makes the tentacles very flexible and a powerful grip to help them capture its prey. These tentacles are used to catch shrimp, fish and small crustaceans. The 90 tentacles play a very important role in the life of a nautilus. Without them it would be impossible for it to capture food.==== ====**Environmental Pressure:** I believe that, their past ancestors did not have any sort of tentacles which made it almost impossible for it to hunt for food. Also possibly this is also responsible for their decline of population in the past. Due to this, the Chambered Nautilus today have tentacles which they can use for capturing food at same time keeping it away from starvation.====

**//Behavior: Laying eggs in shallow water//**
====Nautiluses reproduce by laying eggs. The female takes to eggs to shallow water to keep it safe from predators in order for the egg to hatch properly and to ensure the existence of future generation. Females attach the fertilized eggs to rocks in shallow waters. It will then take 8-12 months for these eggs to be fully developed. Since nautiluses are close to extinction, it is important for them to ensure the survival of future generations.==== ====**Environmental Pressure:** In my opinion, in their past they had been laying eggs in other places where there are lots of predators, which results in eggs being eaten. Due to this, their past generation was not very successful in ensuring their future generation therefore they began to lay eggs in shallow waters where there aren’t as much predators.====

**//Behavior: Descending to darker waters during day//**
====During day time, The Chambered Nautilus descends to darker and deeper waters to avoid predators.Due to their developed shells, they were able to descend to waters about 800m due to the water resistant their shell provides. Their shell would appear darker when seen from above which makes it hard for other marine creatures to spot them at the bottom of the sea where waters are usually darker.==== ====**Environmental Pressure:** I believe that in their past generations, they are easily spotted by their predators and often being hunted. They realize that they are less likely to be hunted by predators in deep waters, therefore they always descend to dark waters during times where predators were usually around.====

**//Physiological: Buoyancy and movement//**
As seen above, buoyancy allows the Nautilus to float and they can alter their density. || ====Inside the shell, there are chamberswhich are individually sealed and contain gases, which provides the animal with buoyancy. In order for it to swim, the nautilus sucks water in and out of the chamber with its hyponome. While the water is inside the chamber, the siphuncle extracts salt from the water and diffuses it into blood. The nautilus can then regulate its density by injecting and removing fluid into these chambers. This would allow the nautilus to swim up to 2 knots. This is an advantage for the nautilus. Since food wont be always floating around the nautiulus, this adaptation allows the nautilus to swim freely and look for food instead of waiting for it.==== ====**Environmental Pressure:** I believe in their past generations, they weren’t allowed to move as freely as it is today which also makes it hard for it to hunt for food. Therefore, they are developed with buoyancy to maximize their agility.====
 * [[image:nautilus_floating.jpg width="206" height="117" align="center"]]

**//Habitat//**
====The Chambered Nautiluses can be found in tropical waters throughout the Pacific and Indian Ocean. This area lies between the [|Tropic of Cancer]in the Northern Hemisphere and the [|Tropic of Capricorn] in the Southern Hemisphere where the temperature never goes below 65F.==== ====The tropical ocean is often referred as the ocean’s rainforest as it contains many different corals. These reefs contain plenty of resources for marine life and it also provides shelter for many marine creatures such as the Chambered Nautilus.==== ====The Chambered Nautiluses usually live on the slopes of coral reefs that descends into deeper waters. During daytime, the Chambered Nautilus descends into deep waters about 550 meters deep and ascends to shallow waters at night to feed among the coral reefs. They descend to deep waters during daytime mainly because there are fewer predators there.====

Nautilus mainly feed on small fish, shrimps and crustaceans. They use their tentcles to capture their food. Due to their lack of energy in swimming, they are only required to feed once a month.
=<span style="color: #00ffff; font-family: 'Comic Sans MS',cursive;">Bibliography = Modern Animal //Creatures of the deep//. (n.d.). Retrieved June 26, 2011, from Sea and Sky: http://www.seasky.org/deep-sea/chambered-nautilus.html

//Nautilus//. (n.d.). Retrieved June 26, 2011, from Wikipedia: http://en.wikipedia.org/wiki/Nautilus

//The Equator//. (n.d.). Retrieved June 26, 2011, from Worldatlas: http://www.worldatlas.com/aatlas/imagee.htm