Humboldt squid (Dosidicus gigas), also known as jumbo squid, jumbo flying squid, pota or diablo rojo, is a large, predatory squid living in the waters of the Humboldt Current in the eastern Pacific Ocean. Humboldt squid are among the largest of squids, reaching a mantle length of 1.5 m (4.9 ft). Like other members of the subfamily Ommastrephinae, they possess bioluminescentphotophores and are capable of quickly changing body coloration (metachrosis). They notably rapidly flash red and white while hunting, earning them the name diablo rojo (Spanish for ‘red devil’) among fishermen. Interestingly, these chromatophores (which belong to more than one set and are of different sizes) may rapidly cycle through colours other than red and white, flashing too quickly for the human eye to see the transitions.
Bioluminescence is the production and emission of light by a living organism. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some bioluminescent bacteria
The uses of bioluminescence include counterilluminationcamouflage, mimicry of other animals whether for offensive or defensive purposes, and signalling to other individuals of the same species, such as to attract mates
A photophore is a light-emitting organ which appears as luminous spots on various marine animals, including fish and cephalopods. The character of photophores is important in the identification of deep sea fishes. Photophores on fish are used mainly for attracting food or confusing predators.