Shiny sharks, fantasy, or reality?

We know that space has been more explored than our seas. This makes it possible to spot unimaginable creatures frequently in the ocean, such as bioluminescent sharks. As you read it: Deep sea sharks emit light similar to that of forest fireflies.

It was recently published An academic article documenting bioluminescence in three species of sharksWhich sparked our curiosity on social media and in us for a few moments. It is true that this is not the first time that this phenomenon has been documented, but surely every time we discover new shiny sharks it will arouse interest because it is still a rare phenomenon.

Bioluminescence is the phenomenon by which living things produce light, and it is observed in various marine groups and in very few terrestrial groups, including fireflies. This is possible due to a biochemical reaction that takes place inside cells or organs which includes an enzyme called “luciferin”, which when interacting with oxygen produces light and makes living things illuminate. (See bioluminescence types at this link). It is mostly documented in invertebrate marine organisms, some of which are microscopic, making the sea floor and sometimes beaches shine.

In sharks, bioluminescence has been reported for some species from three families (Dalatiidae, Etmopteridae, and Somniosidae), which live in deep waters and is not an easily observable phenomenon due to the depths in which they live and the impossibility of humans we can survive for a long time in these environments. These sharks glow because of their “light carriers” or organs in the epidermis where light is produced and they control this emissions with hormones such as melatonin, adrenocorticotropic hormones and prolactin (rare among living organisms). These photograms are found in different parts of the body depending on the species.

The first bright sharks were reported in the nineteenth century, but studies delineating the physiological pathways and the precise location of bioluminescence in these animals are very recent. We now know that the color of the light they emit is a greenish blue, and that the possible effects include hiding their silhouettes from predators that stalk them by producing enough light to match their surroundings, and to deter these same predators from attacking them, even for their identification and communication between organisms of the same kind. .

The post I mentioned at the beginning is amazing because it describes the paper shark, a species that reaches nearly 6 feet in size, making it the largest bioluminescent vertebrate we know of. In the future, we’ll continue to hear great discoveries as technology advances to dig deeper for longer.

None of this would be possible without the budget that marine sciences receive, for which they are Decade of Ocean Sciences for Sustainable Development It encourages the strengthening and diversification of sources of financing that will allow for this type of discovery.

At Oceana, science is our main tool, and we want a future in which the world’s oceans are filled with life and discoveries of new species, which illuminate our efforts to preserve present and future generations.

* Mariana Rina is a biologist with experience in preparing, implementing and evaluating sustainable development, conservation and climate change projects in marine and terrestrial social and environmental systems in the academic sector and in civil society organizations. He completed a master’s degree in coastal oceanography and a doctorate in environment and development, specializing in management issues related to coral reefs. She is currently an oceanographer and fisheries scientist in Oceana.