It’s all just a nice chemical trick. The oxygen that is inhaled by the firefly reacts with substances in its body and the result is the release of energy in the form of light. Scientists call this phenomenon bioluminescence and it also happens in other species, such as the lantern fish Photoblepharon sp., which lives in the depths of the oceans, and a small crustacean called cypridina. Among beetles, scientists have already detected at least three families of luminescents. Fireflies (from the lampyrid family) emit light between green and yellow. Kingfishers (elaterids) produce a slightly different light, ranging from green to orange. The so-called little trains (phengodids) detonate: their light can be green, red, orange and yellow. Some trains even have a red lantern on the head and eleven pairs of yellowish side lanterns on the abdomen, that is, a real luminous panel! “The biological function of bioluminescence is poorly understood, but scientists suspect that it is used to illuminate the field of vision, attract prey, recognize different species and sexual partners and even as a weapon against predators”, says chemist Etelvino Bechara , from the University of São Paulo (USP).
1. The oxygen inspired by the firefly enters through the trachea, which is connected to the insect’s abdomen region. There, there is a type of fabric called a lantern.
2. This abdominal tissue is formed by cells specialized in the emission of light, the photocytes, and is also connected to the animal’s brain. When the firefly wants to blink, the brain releases the neurotransmitter octopamine, which will “turn on” the photocytes in the abdomen.
3. Photocytes start a chemical reaction with three “ingredients”, which you see below
4. Luciferin is a fuel produced by the animal and ATP is the substance that provides energy for cells. These ingredients bind to an enzyme called luciferase, which speeds up the reaction.
5. The result of this reaction is the production of carbon dioxide and a substance with a complicated name: fluorescent oxyluciferin. It is she who releases energy in the form of light. In this whole reaction there is no loss of energy as heat, that is, the light of the firefly is cold