by neufer » Sat Oct 06, 2018 1:32 pm
https://www.sciencedaily.com/releases/2017/02/170228131001.htm wrote:
Frogs have unique ability to see color in the dark
February 28, 2017
<<The night vision of frogs and toads appears to be superior to that of all other animals. They have the ability to see colour even when it is so dark that humans are not able to see anything at all. This has been shown in a new study by researchers from Lund University in Sweden. "
It's amazing that these animals can actually see colour in extreme darkness, down to the absolute threshold of the visual system. These results were unexpected," says Professor of Sensory Biology Almut Kelber at the Faculty of Science, Lund University.
Most vertebrates, including humans, have two types of visual cells located in the retina, namely cones and rods. The cones enable us to see colour, but they usually require a lot of light and therefore stop working when it gets dark, in which case the rods take over so that we can at least find our way home, albeit in black and white.
In toads and frogs the rods are a bit special, however. It was previously known that toads and frogs are unique in having rods with two different sensitivities. This has not been found in other vertebrates, and it is also the reason why researchers have long suspected that frogs and toads might be able to see colour also in low-light conditions. The new study was first in proving this to be true, and the results exceeded all expectations.>>
Journal Reference: Carola A. M. Yovanovich, Sanna M. Koskela, Noora Nevala, Sergei L. Kondrashev, Almut Kelber, Kristian Donner. The dual rod system of amphibians supports colour discrimination at the absolute visual threshold. Philosophical Transactions of the Royal Society B: Biological Sciences, 2017; 372 (1717): 20160066 DOI: 10.1098/rstb.2016.0066
[quote=" https://www.sciencedaily.com/releases/2017/02/170228131001.htm"]
Frogs have unique ability to see color in the dark
February 28, 2017
<<The night vision of frogs and toads appears to be superior to that of all other animals. They have the ability to see colour even when it is so dark that humans are not able to see anything at all. This has been shown in a new study by researchers from Lund University in Sweden. "[b][i][color=#0000FF]It's amazing that these animals can actually see colour in extreme darkness, down to the absolute threshold of the visual system. These results were unexpected,[/color][/i][/b]" says Professor of Sensory Biology Almut Kelber at the Faculty of Science, Lund University.
Most vertebrates, including humans, have two types of visual cells located in the retina, namely cones and rods. The cones enable us to see colour, but they usually require a lot of light and therefore stop working when it gets dark, in which case the rods take over so that we can at least find our way home, albeit in black and white.
In toads and frogs the rods are a bit special, however. It was previously known that toads and frogs are unique in having rods with two different sensitivities. This has not been found in other vertebrates, and it is also the reason why researchers have long suspected that frogs and toads might be able to see colour also in low-light conditions. The new study was first in proving this to be true, and the results exceeded all expectations.>>
Journal Reference: Carola A. M. Yovanovich, Sanna M. Koskela, Noora Nevala, Sergei L. Kondrashev, Almut Kelber, Kristian Donner. The dual rod system of amphibians supports colour discrimination at the absolute visual threshold. Philosophical Transactions of the Royal Society B: Biological Sciences, 2017; 372 (1717): 20160066 DOI: 10.1098/rstb.2016.0066
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