During the summer , Dermochelys coriacea ocean turtle ( Dermochelys coriacea ) swim all along the coolheaded temperate waters of the westerly and easterly security deposit of the North Atlantic , forage for jellyfish . These giants have an odd - looking , non - pigmented pinkish area on the crown of their oral sex ( pictured below ) called the pineal , or simply “ pinkish spot . ” Now , researchers are saying that the maculation functions like a skylight in their skull , allowing the turtles to sense insidious changes in sunshine .
At the ending of summer , the forage turtles work in the south and go forth their feeding priming coat , which can be thou of kilometers from where they spawn . But how they get laid when to start their journey back is a bit of a mystery . To investigate how they feel seasonal changes , a team run byJohn Davenport from University College Corkexamined a database of Dermochelys coriacea sighting in H2O around Great Britain and Ireland . Then they compared those with historical datum for ocean surface temperatures and 24-hour interval length to see if the horizontal surface or periodicity of either environmental triggers would prompt forage turtles to turn south and go away their feeding curtilage at summer ’s end .
They found that , in the study area at least , ocean surface temperature was too variable and too dim to change to be useful as a trigger . Rather , the shortening of sidereal day length as the late summerequiluxapproaches provides a credible cue to the changing season . This discriminative stimulus , which they distrust acts via the pineal , basically evidence leatherbacks to leave their scrounge area , whether it ’s near Nova Scotia or the British Isles .
Furthermore , by examine four leatherbacks ( who werefound dead ) , the team discovered cadaverous construction underneath the pink spot in puerile and grownup polo-neck ( below ) that are compatible with the estimation of a “ pinealdosimeterfunction ” for light stimuli . The layers of bone and cartilage underlying the spot is much thinner there than in other surface area of the skull , Science explain . The realm is so slight , it lets light through to the pineal gland — a part of the brain that helps regulate daytime and night cycles , as well as seasonal design of behaviour . Theworkwas publish in theJournal of Experimental Marine Biology and Ecology .
Images : jimmyweee(top),U.S. Fish and Wildlife Service Southeast Region(middle ) via FlickrCC BY 2.0
