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Squid

Teuthida/Teuthoidea

Squids are 10-armed cephalopod mollusks (eight arms plus two longer tentacles) commonly grouped in the order Teuthida/Teuthoidea, with 300+ species found in coastal and open-ocean waters worldwide. They have an elongated body with a mantle and a funnel (siphon) used for jet propulsion, and most have a flexible internal support called a pen. Like other cephalopods, squids have three hearts and blue, hemocyanin-based blood. Many can rapidly change appearance using skin pigment cells (chromatophores), and some species also use bioluminescence for camouflage or signaling. Most also have an ink sac and can release ink as a defensive smokescreen or decoy.

Squids are 10-armed cephalopod mollusks (eight arms plus two longer tentacles) commonly grouped in the order Teuthida/Teuthoidea, with 300+ species found in coastal and open-ocean waters worldwide. They have an elongated body with a mantle and a funnel (siphon) used for jet propulsion, and most have a flexible internal support called a pen. Like other cephalopods, squids have three hearts and blue, hemocyanin-based blood. Many can rapidly change appearance using skin pigment cells (chromatophores), and some species also use bioluminescence for camouflage or signaling. Most also have an ink sac and can release ink as a defensive smokescreen or decoy.