Firefly squids (Watasenia scintillans) are marine creatures hailing from the waters surrounding Japan, specifically the western region of the Pacific Ocean. The small squids are noteworthy due to being bioluminesce -- they give off light, gaining them their common name.
Firefly Squid Basics
In the daytime, firefly squid are seen in waters of considerable depth, usually between roughly 656 feet and 1,312 feet down. Once night falls, they ascend nearer to the top of the water for dining purposes. These miniscule cephalopods typically grow to lengths of between 2.8 and 3.1 inches. Firefly squids' life expectancies are relatively brief. They generally survive for approximately 1 year. Another name for the species is sparkling enope squid.
One helpful firefly squid adaptation involves their vision. They're actually thought to be the only squids that can see in color. Unlike the majority of cephalopods, firefly squids have three eyesight pigments rather than one. Human beings also have three of these pigments. Their color vision assists them in being able to decipher lighting given off by fellow firefly squids.
Bright Lights as an Adaptation
Firefly squid have the ability to give out irregular blazes of intense light, not unlike fireflies. They possess photophores, which are special organs that enable them to send forth light. They're situated all over firefly squids' physiques. The light they radiate is an intense blue color. Since they have so many of these little photophores, they can practically get their whole bodies glowing blue. Their bioluminescence is a handy survival adaptation that they employ in a handful of different ways. They can intimidate predators with their lights. They can bewilder predators with them, making the outlines of their bodies unclear and thus buying themselves extra time to flee hazardous scenes. They can even draw in possible mates using their lights. Firefly squid spawn between the months of March and May each year. When they congregate to breed, they unwittingly participate in a spectacular light display that brings in lots of human spectators.
Lights and Mealtime
Firefly squid use their bright lights to great advantage when it comes to mealtime. Their convenient lights help them hunt by flaring and therefore luring in nearby prey, particularly fish. Fish, although a big component of their diets, definitely isn't the only thing they eat. Their lights also help them pull in other meals including crustaceans such as crab and shrimp.
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