Invisible sharks, lantern sharks: new study of bioluminescence

The light can make you more visible, but in the same time could help you become invisible sharks seem to found out how this trick works.[googlead tip=”vertical_mare” aliniat=”dreapta”]

A recent study has shown that splendid lantern shark, besides glowing in the darkness of the deep waters, can create through light effects a “cloak of invisibility” wich helps it to avoid predators.

Also, this study gathered provings that the cylindrical-shaped sharks’ habitat is extended around the Okinawa Islands of Japan,in addition to the East China Sea, and the vicinity of southern Japan waters.

Julien Claes, Jerome Mallefet and Keiichi Sato caught three specimens of the splendid lantern shark and they kept them in conditons similar to their natural environment.

The observations they made upon the sharks pointed out that each of them had nine separated bright light emitting areas (photophores). The part on the belly, together with some other areas, are responsible for invisibility effect. More luminous zones are located on the shark’s pectoral fins, flanks, tail and sexual organs, probably involved in schooling and sexual communication.
The researchers think the process is controlled by nerves and hormones in the first way,   secondly the pigments are moving in the cells to accomplish the final effect.

 

Invisible sharks do really exist as a result of a natural phenomenon called bioluminescence.

There are a number of bioluminiscent animals, they use bioluminescence to lure, to repell, to camouflage, to illuminate and even to communicate,  but not all of them can become invisible. How splendid lantern shark produce its shield is explained by Julien  Claes who said to Discovery News:

[googlead tip=”patrat_mare” aliniat=”centrat”]

“The photophores replace the down-welling light from the sun, which is absorbed by the shark’s body.The silhouette of the shark therefore disappears when seen from below.”

It is like someone puts a powerfull light into your eyes, I would say. You can see the light, but everything else becomes invisible, such as invisible sharks.

It is interesting to mention that another small dogfish shark, cookiecutter shark, can be only partially visible in order to attract prey.

Julien  Claes is a scientist of the Catholic University of Louvain’s Marine Biology Lab. During the recent years he and his fellows colleagues have also studied the velvet belly lantern shark, another small dogfish which also has this feature (invisibility).

Picture credit: Wikipedia.

[googlead tip=”lista_mare” aliniat=”centrat”]