Colossal squid

The colossal squid is a species of squid known by the scientific name Mesonychoteuthis hamiltoni. They are perhaps best known for being the largest invertebrate alive. The giant squid and the colossal squid are both very big, but what make the colossal squid the largest is that the colossal squid is wider even though the giant squid is slightly longer. They also have the largest beaks and eyes. The eyes are about the size of soccer balls. What makes the colossal squid different and interesting from other squids is its arms/tentacle. On the eight arms are hooks in the middle and suckers. Now these are not the average suckers they have little teeth on the inside of them. The giant squid only has these suckers. Where as the colossal squid have on their tentacles swiveling hooks that can turn 360 degrees. The only place that these creatures are found is deep in the waters near Antarctica. Most of the information learned about them is from the stomachs of beached sperm whales. In 2007, the first alive one was captured by humans, as it was accidentally dragged up by the line of a fishing boat. This colossal squid was preserved and is now on display at New Zealand's National Museum, Te Papa in Wellington until August 2013.

Body Design
The colossal squid, like many other squids, have a mantle, head, fin, tentacles, and arms. The main body of a squid is called the mantle. This covers the internal organs and is made of muscle and skin. The skin has a pigment with cells called chromatophores. These cells give off a reddish pink color showing that it is ready to attack. When they contract, the cells in the skin appear paler. The colossal squid has a mantle that is roughly 2.5 meters long and 982 millimeters wide. This is about the size of a truck tire. The colossal squid has an internal shell called the gladius. The gladius supports the body of the squid. It runs through the upper part of the mantle and between the paired tail fin. The gladius is made of chitin. (a tough, protective, and semitransparent substance) The paired tail fin is connected to the top of the mantle. The fin is 1,183 millimeters long and 982 millimeters wide. This makes it easier for them to move more quickly to attack their prey. The funnel or siphon is on the ventricle side. It is used for respiration, expelling waste, and movement. The mantle expands when it sucks up water into the mantle cavity. When this happens oxygenated water flows over the gills for respiration. All squids have blue blood. The mantle contracts shooting water out and waste along with it. This is how squids move by jet propulsion. The head of the colossal squid contains its eyes, brain, and its esophagus. Its eyes are the largest known with a diameter of about 27 cm. Their brains are small and donut shaped with the esophagus going in between it.

Life Cycle
The reproduction of the Colossal Squid is not very well known because only females have been found. It is known that the female is larger. Scientists have hypothesized different ideas of what their reproduction may be. One thought is that the male has a penis and has a reproduction similar to the Teuthowenia pellucida (googly-eyed glass squid), a related species which lays eggs. . In general, many squids have precopulatory rituals, which is when males seize females with their tentacles before mating. Their fertilization is likely internal. The early stages of the colossal squids life are concentrated beneath the surface layer in the upper zone of the warm deep water, because at this depth biological activity is higher from the spike in phytoplankton biomass. The colossal squids have a slow pace of life and it is said that they can survive on one toothfish for a few days.

Ecology
The colossal squid lives in extremely deep and cold waters off Antarctica.They live about 1000 meters under water. Only once the colossal squid has be seen alive and caught. A fishing boat, while fishing for toothfish pulled up a colossal squid that was eating one of the toothfish they caught. They hauled it onto their boat and then froze it so the museum Te Papa in New Zealand would have a nice specimen. The first report of the colossal squid was in 1925. They found the squid's head and arms in a sperm whale's stomach. Studying beached Sperm whales stomachs show that about 76-77% of their diet consists of colossal squids. Most of the information about the colossal squid from the stomachs of sperm whale. The sleeper shark eats 52% of its weight in colossal squid. Wandering albatross, Patagonian and Antarctic Toothfish are also some of their predators. Since 1925 only 8 colossal squids have been found and of that 6 were rescued from whales' stomachs. Their beaks are not digestible in the sperm whales stomach, so when scientist go through the whales stomachs there are large amounts of beaks in the stomach.

Popularization
The colossal squid caught the eye of the public when the squid was miraculously pulled out of the water by the fishing boat Ross Sea. A live internet feed webcam watching the specimen defrost When it was defrosting many of those days the press was there. Which made it hard for the scientist to study it. It was on the news in New Zealand for many days. Since being preserved, the colossal squid has been on exhibit in New Zealand's national museum, Te Papa since December 13, 2008. The museum has created many online resources and interactive resources to educate about the colossal squid. The Discovery channel and BBC made a documentary about the colossal squid called, Colossal Squid. In New Zealand they have a kid show, Octonauts, which featured an episode of the colossal squid. Also, in an art festival there was a colossal squid float. The colossal squid and a sperm whale was feature on a stamp issued by South Georgia and South Sandwich Islands.

Video
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More information
On the Te Papa's website they made a interactive learning tool about the anatomy of the colossal squid.link title