Vampire Squid ( Vampyroteuthis infernalis )

The vampire squid, known to scientists as Vampyroteuthis infernalis , looks like something that swam out of a late-night science fiction movie. In spite of its monstrous name, it is a small creature, growing to only about six inched in length. The vampire squid is an ancient species and is a phylogenic relict, meaning that is the only surviving member of the order vampyromonophida. It is a unique member of the cephalopod family in that it shares similarities with both squid and octopuses. In fact, it was originally and mistakenly identified as an octopus by researchers in 1903.

The vampire squid has large fins at the top of its body that resemble ears. These fins serve as its primary means of propulsion as it literally files through the water by flapping these fines. As with other squid, it can also use jet propulsion to move by expelling water through a specialized siphon jet located just under its mantle. The vampire squid has a very gelatinous from, resembling a jellyfish more than the common squid.

Through it is relatively small, growing to a length of only about six inches, it has globular eye balls about the size of those of a large dog. These large eyes can appear red or blue in color, depending on the light. The vampire squid's eight arms are connected with a webbing of skin, which makes it look more like an octopus than a squid. When threatened, the squid can draw its arms up over itself and form a defensive web that covers its body. Each of the eight arms is lined with a single row of suction  cups and rows of soft , fleshy spines known as cirri.

It is these spines, along with the cape- like webbing and red eyes that give the vampire squid its unusual name. Located inside the vampire squid's webbed arms can be found a pair of retractable sensory filaments. These filamnets are similar to the two long tentacles found on other squid species. Also located within the webbing are two powerful beak like jaws. These jaws are as white as ivory and are strong enough to crush the shells of crustaceans.. the squid's color ranges from jet black to pale red.

The vampire squids body is covered with light- producing organs called photophores. This gives the squid the unique ability to turn itself on or off at will through a chemical process known as bio luminescence  When the photophores are off, the squid is completely invisible in the dark waters where it lives. The squid has incredible control over these light organs. It has the ability to modulate the size and intensity of the photophores to create complex patterns that can be used to disorient predatators and attract prey.

The distribution of eggs has been found to be similar throughout the year, indicating that there may be no particular breeding season. Once the eggs hatch, the young hatchlings will drift with the water They resemble miniature versions of the adults except that they lack the webbing between the arms and their eyes are much smaller. As they devolop, the young vampire squid undergo what has been described as a double mentamorphosis. At early stages of development the young squid have a single pair of fins located near the eyes. At the animal reached maturity. these fins are resized and repositioned to maximize swimming efficiency.

Vampire squid are found throughout the deep oceans of the world in most tropical and temperate regions at depths of between 90 meters and 900 meters. They live in the oxygen minimum layer of the ocean where virtually no light penetrates. They seem to prefer a temperature between 35 and 43 degrees Fahrenheit (between 2 and 6 degrees Celsius)

Chambered Nautilus (Nautilus pompilius)

The curious-looking chambered nautilus, also considered a living fossil. Nautilus pompilius is the largest and most common of about six species known to exit. Like the coelacanth for over 400 million years. During prehistoric times, there were about 10000 different species of nautilus, but only a handful are known to survive today.

The nautilus is a mollusk and a member of the cephalopod family. It is closely related to other cephalopods such as the squid, cuttlefish,and octopus. Like most cephalopods, it can use jet propulsion to attain speed of over two knots. A small tube near the animal's tentacles, known as a siphon, expels water under pressure. This propels the nautilus in the opposite direction at high speed.

The life and habits of the Nautilus are still largely a mystery, since it spends most of its time in deep water. The shell of the nautilus is comprised by many individual chambers. Each chamber is individually sealed and contains an amount of gas. The nautilus can regulate its density by injecting or removing fluid into these chambers through a system of tubes. This strong shell also provides protection for the animal's soft body. The nautilus has many more tentacles than its close cousins. Depending on the particular species, there can be up to 90 separate tentacles. The tentacles are arranged into two circles, and unlike those of other cephalopods,  they have no suction cups. These tentacles are used to catch shrimp, fish and small crustaceans, which the animal crushes with its powerful beak. Nautiluses are active predators, but since their siphon system uses very little energy while swimming, they only need to eat about once a month. Their eyesight is very poor because their eyes contains no lenses. Instead, there is only a tiny hole to allow light into the eye.

The  Nautilus reproduces by laying eggs. the eggs are usually attached to rocks in shallow water, hidden away from curious predators. These eggs require between eight and twelve months to fully develop. When a young nautilus first hatches from its egg, it is about an inch in diameter and has a shell with seven chambers.

Nautilus are found throughout the pacific and Indian oceans, where they spend their daylight hours at depths of about 1,800 feet (550 meters). At night they migrate to shallower waters to feed among the coral reefs. The shell of the nautilus cannot withstand the pressure of depths greater than 2,600(800 meters). Unfortunately, nautilus populations are on the decline due to the harvesting of their beautiful shells.