Anatomy of a Squid

Architeuthis, as it is a squid, has anatomy identical to that of any other squid of smaller size, except its organs are proportionately larger, as the creature as a whole is larger.  The only aspect that differs is the size and shape of the head, which is different for every species of squid.  The average length of a giant squid is 13 meters (43 ft) for a female and 10 meters (33 ft) for a female, whereas most squid do not exceed the size of 60 cm (24 in).

Squid are symmetric along the width of their body which lets them easily move around in the water.  The head of the squid is what makes it unique.  The head has a large volume, but it is flat.

Squids have eight arms with suckers.  The suckers run the entire length of the arm on one side.  The suckers of Architeuthis are two to five centimeters in diameter.  There are also two longer arms called  tentacles.  These tentacles do not have suckers on the whole length; the suckers are only on club-like ends of the tentacle.

The cavity of the body of a squid is called its mantle.  The mantle protects the squid as it moves in the water.  It also helps to keep in the nutrients the squid takes in so that it can survive.  The mantle of a giant squid is approximately two meters (6.6 ft) long.

One of the most important features of a squid is its siphon. The siphon is located under the head of the squid. One of its uses include locomotion by jet propulsion. The siphon can change the direction it faces to allow the squid to travel forward and backwards. Other uses for the siphon include waste excretion and the releasing of the squid’s defensive ink, which serves a distraction while the squid escapes.

Another important body part of the squid is the fins. They are located on either side of the mantle of a squid, and they are used to steer the squid. However, unlike most other marine life, the fins do not provide the main method of transportation.

The foot long eye of the giant squid next to Zoologist Dr. Clyde Roper

The eyes of squid are quite fascinating. Squid have the largest body to eye ratio of any animal in the Animal Kingdom. Architeuthis has the largest eyes of any living creature on the face of the planet, with the possible exception of the colossal squid, with a diameter of one foot. The eyes of a squid have 360 degree visibility. Although squid are colorblind, they make up for it because of their extremely excellent vision, possessing good day and night vision.

In the middle of the arms and tentacles lies the beak of the squid. The parrot-like beak of the squid serves as its mouth. For a very in-depth look at the beak of a squid, go to this link:

Squid are a very intelligent animals for invertebrates. Their brain to body ratio is very high, resulting in a higher intelligence. Many squid hunt cooperatively, exhibiting a great deal of intelligence.

Another one of the most unusual characteristics of squid is their three hearts. The main heart circulates blood through the entire body. The other two hearts which provide blood to the gills.

The anatomy of the squid is one that is very unique and special, even among other cephalopods.


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