Yes, some fish, particularly freshwater fish like salmon, can see infrared (IR) light and have even evolved mechanisms to enhance this ability.
Research indicates that certain freshwater fish, such as salmon, are capable of perceiving infrared light. When these fish migrate from the clear open ocean to the murkier inland freshwater streams, they need to adapt their vision to navigate effectively.
According to a study, "Freshwater fish, amphibians supercharge their ability to see infrared light." The reference specifically states that "To navigate the murkier freshwater streams and reach a spot to spawn, the fish have evolved a means to enhance their ability to see infrared light."
This suggests that the ability to see light in the infrared spectrum is a crucial adaptation for these species, helping them find their way and survive in environments where visible light may be limited or scattered differently than in the ocean.
Why Can Some Fish See IR Light?
The ability to perceive infrared light in certain fish is linked to their environment and navigation needs.
- Murky Waters: Freshwater streams can be significantly murkier than the open ocean due to sediment, algae, and other particles. This limits the penetration and visibility of typical visible light.
- Adaptive Evolution: Fish migrating into these conditions have evolved specialized visual systems. As the reference notes, they "have evolved a means to enhance their ability to see infrared light." This enhancement helps them detect objects and navigate in conditions where standard visible light vision is less effective.
- Supercharging Vision: The term "supercharge" highlights that this isn't just a marginal ability but a significant improvement in their capacity to utilize the infrared part of the spectrum for vision.
Practical Implications
While the specifics of how they enhance their IR vision are complex, the fact that they can do so illustrates the remarkable adaptability of biological systems to environmental challenges. This capability allows fish like salmon to successfully complete vital life cycle stages, such as migrating upstream to spawn.
- Navigation: IR vision likely helps them identify obstacles, follow contours, or even detect the thermal signatures of objects in their path in low-visibility conditions.
- Foraging/Predation: While the primary mention relates to navigation, the ability to see into the infrared could potentially also aid in locating prey or avoiding predators in dark or murky environments.
In summary, while not all fish possess this ability, freshwater fish, particularly those undertaking migrations in low-visibility waters, can indeed see and even enhance their ability to see infrared light as a key survival mechanism.
