Can fish see in the dark? This question is so simple, but their answer is much more complicated than this question.
Research showed that there are a lot of questions that people have asked about fish that can fish see at night, can fish tanks give light to fishes, can fish see when there is no light anywhere?
Science told people by research that fish can see in the dark because they have an extra-large eye than other species which have unique features in their organs.
But the question is that why would we be too curious about a fish vision journey?
Scientists can give the answers to all our questions about why fish can see in the dark and what benefits could their vision have?
This article can provide you a lot of knowledge about fish vision and their eye morphological structure and their unique features that other species don`t have.
If you think fish is a simple species then you are wrong, fish are the most complex and complicated species, especially their eye structure.
This content will open your mouth wide about the fish multitasking vision-catching thing and their rods and retina function.
Main components of the fish vision:
The main parts of the fisheye are their retina, lens, Corea and rods. Eye structure is a plus point to all the species in the aquatic environment, especially fish. These pairs of eyes have benefited the fish by seeing the fascinating views of the marine habitat.
Also, they have sharp eyes to protect them from their predators and live in the challenging environment.
Cornea:
The first and the most important part of fisheye is cornea. It is the transparent, spherical white area that a fish has. Its function is to give light to the fish for seeing the view all around.
It lies in the core of the eye. It is just like a transparent sheath that prevents harmful light and things.
Retina:
The other component that a fish has is retina (rods and cones). The fisheye is just like the species living in the forest or jungle.
They also have sharp, wide pupil almond shaped eyes that move their pupil from left to right for protection against hunters and some species have irises that control the width and diameter of the eye of the fish.
This is an important role for their survival. The rods have such types of receptors that pick and view black and white images in low light situations.
While the cones have such cells or receptors in their eye that view all coloured images in better light situations.
Lens:
This is the most important key in the fisheye structure. This is a spherical, wide and stretchable sheath that a fish has. The variable features a fish lies in the lens is that they are more spherical and wider than human lens or other species.
This unique feature is found in the marine fish species that face the challenges for their survival.
Additionally, their lens is not able to move. This is fixed to keep focus on their surroundings. Their habitative ability is in the terrestrial and aquatic species to keep focusing on their surroundings and save them from harmful species.
How does fisheye work in the dark?
The two fish living in the same habitat do not have the same capability of focusing on the environment. Every fish has a different ability to see and view the surroundings.
For example, yellowfin tuna has excellent vision. Their fast swimming in the water is because of their focused and sharp retina and lens.
On the other hand, the dragonfish that is found in the depth of the water has poor vision because of low light conditions. They cannot focus on their surroundings in the high light that’s why they live in the deep-sea water.
Vision of fish is so complicated, because they live in the water. The vision can be blurred due to various conditions like fog, rain and pollution or dust.
Fish adjusting their vision from light to darkness:
- In the bright light, their vision particles of rods and cones work differently in different ways. The rods bend their angle of light while cones move straight to get light into the eyes to see the view.
- While in the dark night, they also work but in opposite ways. The rods move straight to get light to see surroundings, the cones deflect the light to prevent them from harm.
- This procedure takes almost 50-60 mins.
How light penetrate in the water:
We have studied a lot about fish life that live away from the sunlight, such as deep-sea fish.
Eye adaptation is an extraordinary case for the deep living creature, but when we explore their cases, we found that deep-sea fish can also see views with colored images.
Let’s talk about light works in deep-sea water. As we go down in the deep water, the light goes dim.
After some more depth, almost (1000) depth meters below, there is no light. Fish lens can be wider to see the reflexive views up to 1.67. their eyes are wider and more spherical than humans.
As the sunlight has 6-7 wavelengths of light, penetration of light changes when we go downward, and vision also works differently. It is also dependent upon water quality conditions and their temperature.
UV-wavelength penetration:
Some fish also detect species or things due to mutation or disorganized sequence in their genes. This detection is about 360 nanometers that see from their retina or lens.
After some research, scientists showed that this reflection of light is due to mutant genes or some attractive reflection, this increases the captivation of view. But this bending of light is used in some limit of time.
Variant adaptation of fisheye in a period of times:
“The lens of the fisheye is grabbed by the special muscles of the eye. This condition is called accommodation.”
This mechanism is important for making the fish fast, sharp and active. This helps the fish to make focus on the surroundings and see the view clearer.
For example, flatfishes that live in the depth of the water, have one extra eye inside their body, which also performs a unique feature, but that one eye is blind.
Fish used to adapt lateral lines in their life for the benefitted life. They use hair cells to move straight or examine the direction.
Fish are the complex species that their eyes, vision sense, hearing or body structure are more complex than other creatures.