Anatomy of the market squid
Arm: Commonly mislabeled as tentacles, the 8 arms of cephlapods are typically the same size.
Beak: The beak is used for tearing and ripping flesh from other animals, then it goes down the hatch. The beak is made of chitin and is often indigestible by other squid-lovin' animals like sperm whales, so they can often be found in their stomachs.
Chromatophores: These are skin pigments used to change colors and blend into their surroundings. Using a relative of the market squid, scientists have also recorded how chromatophores flash when electrical signals from an iPod stimulate the muscles that control them.
Eye: Like many other cephalopods, the market squid is a highly visual predator. While human eyes have to bend their lens to focus on an object, squid eyes can move the position of their lens like that in cameras and telescopes. The market squid's eye also contains a cornea.
Fins: Although some squid use their fins as the primary source of locomotion, the market squid uses jet propulsion from the siphon to move through the water. The fins do provide stability as it moves.
Gladius: Unlike its relatives snails and clams, most cephlapods have reduced or have lost their ancestral shell. The squid's shell has been reduced to the gladius, or internal pen (it actually can serve as a rudimentary pen when dipped in ink!). The gladius is made of chitin, and it supports the squid's mantle and serves as the site for muscle attachment.
Mantle: The mantle houses the main organs of the squid.
Siphon: By relaxing and contracting the mantle, water can be pushed through the mantle and out of the siphon to provide propulsion.
Suckers: Suckers suck like suction cups suck (Repeat this 5 times). Some larger squids have hooks or claws around their suckers to lock into their prey's flesh.
Tentacle: The two longer limbs are the tentacles. It helps to provide stability as it moves through the water.
Mustache: Contrary to our illustration, squids do not have wild-west mustaches to disguise themselves when necessary. Sorry to burst your bubble.
Drawn by Dana Song. Written and Edited by Kaitlyn Lowder and Garfield Kwan.