looks like a starry sky
Waitomoo caves have become an attraction in New Zealand thanks to an insect that inhabits their interior. In the larval stage, the luminous arachnocampa it builds sticky webs on walls and uses its blue glow to attract flying insects. Victims get stuck and turn into lunch. And we humans marveled at the light show…
attack and defense
It is believed that about 90% of marine organisms in abyssal regions have this gift. O dragon fish (Grammatostomias flagellibarba) uses it both for attack (its “goatee” attracts prey) and for defense (when faced with a predator, it opens membranes on its belly that reveal a frightening glow)
a brilliant partnership
In some cases, bioluminescence is generated by the organism itself. In others, by bacteria, which cooperate in symbiosis with the host. One example of the latter type is the angler fish (melanocetus johnsonii), which appeared in Looking for Nemo. It uses an appendage on its head filled with glowing bacteria to attract prey.
Green light
Although the scientific name might suggest, the Brazilian hyena is not found here. This marine snail that inhabits the rocky coasts of Australia intrigues researchers. When endangered, the mollusk retracts and begins to emit green flashes. The curious thing is that its shell amplifies this color, but is opaque to all others.
headlights on
The lights of this larva and adult females of this beetle explain the nickname «little train». O Phrixothrix hirtus, found in Brazil, has 11 pairs of green “lanterns”, which attract prey. But the charm is the red light on the head, the only one of its kind in terrestrial beings. Researchers believe that it serves to light the way and look for food. Many of these animals in the Brazilian fauna are studied by the Biota-Biolum project, from UFScar
Every buzz is a flash
Vaga-lume is the popular name for thousands of species of beetles, including the Aspisoma lineatum. In Brazil alone there are about 500 of them, which emit bioluminescence from different parts of the body and with different signaling patterns and colors. In general, they shine to attract sexual partners, when they are adults, and not to become food for other animals, in the larval stage.
I saw gnomes
The show is not restricted to the animal kingdom. In tropical forests, more than 70 different types of luminescent fungi have already been catalogued, such as mycena luxaeterna and the Mycena chlorophos. Most have little shine. Although some are toxic, there is no consensus on how and why they emit light. It can be to attract insects, spread spores or even protect yourself.
What comes from below doesn’t reach me
the jellyfish aequorea aequorea uses this trick in a curious way. It produces a bluish glow so that, when viewed from below, it is confused with surface light. Already the colleague atolla wyvillei, which inhabits abyssal regions, prefers to frighten rather than deceive. In the face of a predator, it releases an alarming light.
Shake before it glitters
You can also find this phenomenon in the surface layers of the seas. Blame it on dinoflagellates such as Noctiluca scintillans. These single-celled algae emit light when they become «agitated». This can be seen at night, even in Brazil, when waves break on coastlines that have a high concentration of these beings.
THE MAKING REVENUE
Light is generated in an oxidation process
1) The biochemical reaction that generates light varies from organism to organism. But some details are common to all of them. First, a catalyst molecule (facilitator of a biochemical process) generically known as “luciferin” associates with a protein called “luciferase”.
two) Luciferin is then oxidized with oxygen (O2) and becomes energetically excited
3) Upon returning to its ground state, it dissipates this energy in the form of light.
CONSULTANCY Vadim Viviani, professor and coordinator of the postgraduate program in genetics and evolution at UFSCar, and Rogilene Prado, researcher at the biochemistry laboratory of bioluminescent systems at UFSCar
SOURCES Websites BBC, International Society of Bioluminescence and Chemiluminescence It is biolum.net; book Before the Fireflies Go Away – The Influence of Artificial Lighting on the Environment, by Alessandro Barghini; articles “A Caterpillar of the Red Nose”, by Igor Zolnerkevic, and “Marine Bioluminescence – Why do So Many Animals in the Open Ocean Make Light?”, by Edith Widde