Firefly squids, known scientifically as Watasenia scintillans, are small cephalopods found primarily in the waters off Japan. They are famous for their bioluminescent abilities, which allow them to produce a beautiful blue-green light. This light is used for communication and attracting prey, making them a fascinating subject of study in marine biology. These squids typically grow to about 7 to 10 centimeters in length and are most commonly seen during their spawning season in spring. Firefly squids are often harvested for food and are considered a delicacy in Japanese cuisine, where they are enjoyed both fresh and in various dishes.