Saturday, September 3, 2011

Tubarão rare that it shines in the dark one can become “invisible”

The first detailed study of rare the splendid Tubarão lantern (splendid lantern shark, Etmopterus splendidus) it discloses that it not only shines in the dark one, but its effect of light create a “mantle of the invisibilidade” protects that it of predators.



The research is also the first one to around register the presence of the Tubarão of cylindrical form in waters of the Okinawa islands, in Japan. Previously, it was confirmed that the Tubarão existed only in the Sea of Eastern China, to the plaza of Taiwan, and in waters to the south of Japan.



Its spectacle of natural light, produced for fotóforos called emitting agencies of light, serves for some functions. Perhaps the layer of the invisibilidade is most beneficial of these functions, therefore it helps to protect the small Tubarão.



“The fotóforos substitute the light of the sun, that is absorbed by the body of the Tubarão”, the scientist Julien Claes explains. “The silhouette of the Tubarão, therefore, disappears when seen of low”.



The researcher and its colleagues had collected and kept three units of the Tubarão lantern in captivity.



The analyses had disclosed that each one had nine distinct luminous zones. Some of these zones, as one in the belly, contribuíam for the effect “mantle of the invisibilidade”. Others, still more shining, were gifts in the sexual agencies, the flanks, the tail and pectoral paddles of the Tubarão.



The researchers suspect that these zones are probably used during adestramento and sexual communication. “The tubarões use internal fertilização, therefore the presence of fotóforos in the sexual agencies can facilitate the acasalamento”, said Claes. “Moreover, also it can be a way tubarões to signal them that they are ready to acasalar, or that they are better candidates for the reproduction”.



The scientists also believe that mainly the nerves and hormones control the light, with pigments if moving cells as party to suit.



This luminescence probably evolved when the tubarões lantern had colonized the deep one of the sea during the end of the Cretáceo, the 65 75 million years behind. The splendid Tubarão lantern, today, lives of 200 the 1,000 meters below of the surface, areas with extremely low levels of light.



Previously, the same team studied another member of this family of tubarões, lixinha of the fundura (velvet belly lantern shark, Etmopterus spinax). As much this as the splendid Tubarão lantern has luminous zones and other similar characteristics.



It is, therefore, probable that its capacity to shine evolved very before its clado one (group of organisms originated from only ancestral a common one) dividing, at least 31,55 million years behind. It is until possible that many other prehistoric marine animals could shine in the dark one.



“Unhappyly, the phenomenon of the bioluminescência in soft fabrics does not leave, or leaves few, fósseis tracks very”, said Claes. “Therefore, it is very difficult to establish if animal prehistoric they were luminous, but it is probably the case, at least in the deep one of the sea”.



At least 33 species they exist in this family of Tubarão, however, still has very to be discovered on these inhabitants of the deepenings of the ocean.

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