Australian researchers have released a new study showing an interesting new cell in the eyes of the deep-sea pearlside fish. The interesting thing about these cells is that they are composed of both rod and cone photoreceptor cells.
Sometimes called Mueller's bristle-mouth fish, pearlside fish are a specific kind of hatchetfish mostly found in tropical regions of the Pacific and Atlantic Oceans. Researchers believe these fish must have adapted special rod-cone cells to help them see in the dark. Most pearlside fish live about 650 feet below the ocean's surface.
In their report, study authors stress that these new cells actually combine different functions of rods and cones into one cell. Instead of having to use combinations of separate rods and cones to see in the dark (as humans do), pearlside fish are able to amplify the one photoreceptor they need more of to see clearer.
Fanny de Busserolles, a postdoctoral research fellow at the Queensland Brain Institute, was the lead researcher on this study. All research was conducted at the University of Queensland in Brisbane.
In a statement to the press, Dr. de Busserolles said the findings from this study challenge our standard medical understanding that rods and cones have separate duties in a person's vision. She added, "The findings improve our understanding of how different animals see the world and how vision might have helped them to conquer even the most extreme environments."
Both rods and cones are classified as photoreceptors and are located in the eyes' retinae. Basically, photoreceptors are responsible for changing light signals into brain waves for the visual cortex to process. Rods are more associated with night vision and cones are associated with vision during the daytime.
Queensland scientists are already planning a few studies to follow this groundbreaking research. Biologists want to look into the eyes of deep-sea fish to see if they have the same photoreceptor cells found in pearlside fish. They also want to look at the eyes of pearlside fish larvae to see how these cells form in the first place.
Anyone interested in learning more about this research should pick up the latest edition of Science Advances. This article was published under the title, "Pushing the limits of photoreception in twilight conditions: The rod-like cone retina of the deep-sea pearlsides."