Eye diagram of a Trout Perch
EYES - The structure of a Trout Perch's eye is the same as other vertebrates, other than they have a more dense and spherical lens.
The sclera is the white over coat of the eye and acts as protection from injury, as well as providing attachment for the extraocular muscles that move the eye.
The fovea is a tiny area of the eye that is responsible for central, sharp vision.
The retina receives the light the lens has focused and converts it into neural signals.
The optic nerves transfers visual information from the retina to the brain.
The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances. In fish species such as the Trout Perch the lens is denser and more spherical. Because of this, their eyes are able to form very sharp images free from spherical aberration ( a loss of definition in the image), which is particularly beneficial in murky waters or where light rays are coming down and flickering in water.
Light enters the eye via the pupil and the iris regulates the amount of light by controlling the size of the pupil.
The cornea functions as the eye's outermost lens and controls and focuses the entry of light into the eye.
The aqueous humour is the watery fluid between the cornea and the crystalline lens. It maintains the pressure needed to inflate the eye and provides nutrition for the central cornea and lens as they do not have their own blood supply.
The conjunctivia is a thin, semi-transparent membrane that covers the exposed white of the eyeball. It also lines the inner eyelids in most animal species but fish, including the Trout Perch, do not have eyelids as their eye do not dry out in the moist, underwater environment they live in.
The virteous humour is a clear jelly that fills the middle of the eye and lies between the crystalline lens and the retina. It minimally contributes to the optical power of the eye and has a small role in maintaining the structural stability of the eye and retinal health.
The Trout Perch has its eyes structured in such a way because it lives in both an aquatic environment and are a prey species for many of the larger, predatory animals. Their eyes help them to spot the small creatures they feed on and watch out for any signs of approaching predators.
NARES - The nares of a Trout Perch are two small holes on both side of the fish above the mouth.
The nares do not open into the back of the mouth and are not used for breathing. They lead into organs of smell which are very sensitive so the Trout Perch can detect food from considerable distances.
MOUTH - The primary function of a fishes mouth is to intake food. The structure and size of the mouth depends on the food a fish species eats. Trout Perch eat a variety of small aquatic animals such as waterfleas so their mouth is small and non-complex with no sharp teeth or fangs.
SCALES/LATERAL LINE SYSTEM - The Trout Perch has thin, flexible plates of bone or leptoid scales. While these may play some small part in the sensation of touch, the lateral line system functions more as the fishes main tactile organ.
The lateral line system is a system of sense organs found in aquatic vertebrates used to detect movement and vibration in the surrounding water. This plays an essential role in orientation, finding food etc.
This sensory ability is achieved via modified epithelial cells, known as hair cells, which responds to displacement caused by motion and transduce them into electrical impulses via excitatory synapses.
ELECTRORECEPTORS - Electroreception is the biological ability to perceive natural electrical stimuli. Electroreceptive animals, such as the Trout Perch, use this sense to locate objects around them. There are two forms of electroreception.
In active electrolocation the fish senses its surroundings by generating electric fields and detecting distortions in these fields using electroreceptor organs. This electric field is generated by means of a specialised electric organ made of modified muscle and nerves.
In passive electrolocation the fish senses the weak bioelectric fields generated by other animals and uses it to locate them. These electric fields are created by all animals due to the activity of their nerves and muscles.
The Trout Perch use this sense to help them avoid predators and find food in murky or dark underwater conditions.
The sclera is the white over coat of the eye and acts as protection from injury, as well as providing attachment for the extraocular muscles that move the eye.
The fovea is a tiny area of the eye that is responsible for central, sharp vision.
The retina receives the light the lens has focused and converts it into neural signals.
The optic nerves transfers visual information from the retina to the brain.
The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances. In fish species such as the Trout Perch the lens is denser and more spherical. Because of this, their eyes are able to form very sharp images free from spherical aberration ( a loss of definition in the image), which is particularly beneficial in murky waters or where light rays are coming down and flickering in water.
Light enters the eye via the pupil and the iris regulates the amount of light by controlling the size of the pupil.
The cornea functions as the eye's outermost lens and controls and focuses the entry of light into the eye.
The aqueous humour is the watery fluid between the cornea and the crystalline lens. It maintains the pressure needed to inflate the eye and provides nutrition for the central cornea and lens as they do not have their own blood supply.
The conjunctivia is a thin, semi-transparent membrane that covers the exposed white of the eyeball. It also lines the inner eyelids in most animal species but fish, including the Trout Perch, do not have eyelids as their eye do not dry out in the moist, underwater environment they live in.
The virteous humour is a clear jelly that fills the middle of the eye and lies between the crystalline lens and the retina. It minimally contributes to the optical power of the eye and has a small role in maintaining the structural stability of the eye and retinal health.
The Trout Perch has its eyes structured in such a way because it lives in both an aquatic environment and are a prey species for many of the larger, predatory animals. Their eyes help them to spot the small creatures they feed on and watch out for any signs of approaching predators.
NARES - The nares of a Trout Perch are two small holes on both side of the fish above the mouth.
The nares do not open into the back of the mouth and are not used for breathing. They lead into organs of smell which are very sensitive so the Trout Perch can detect food from considerable distances.
MOUTH - The primary function of a fishes mouth is to intake food. The structure and size of the mouth depends on the food a fish species eats. Trout Perch eat a variety of small aquatic animals such as waterfleas so their mouth is small and non-complex with no sharp teeth or fangs.
SCALES/LATERAL LINE SYSTEM - The Trout Perch has thin, flexible plates of bone or leptoid scales. While these may play some small part in the sensation of touch, the lateral line system functions more as the fishes main tactile organ.
The lateral line system is a system of sense organs found in aquatic vertebrates used to detect movement and vibration in the surrounding water. This plays an essential role in orientation, finding food etc.
This sensory ability is achieved via modified epithelial cells, known as hair cells, which responds to displacement caused by motion and transduce them into electrical impulses via excitatory synapses.
ELECTRORECEPTORS - Electroreception is the biological ability to perceive natural electrical stimuli. Electroreceptive animals, such as the Trout Perch, use this sense to locate objects around them. There are two forms of electroreception.
In active electrolocation the fish senses its surroundings by generating electric fields and detecting distortions in these fields using electroreceptor organs. This electric field is generated by means of a specialised electric organ made of modified muscle and nerves.
In passive electrolocation the fish senses the weak bioelectric fields generated by other animals and uses it to locate them. These electric fields are created by all animals due to the activity of their nerves and muscles.
The Trout Perch use this sense to help them avoid predators and find food in murky or dark underwater conditions.
Scales of the Trout Perch
Nares/Mouth of the Trout Perch
Lateral Line system diagram of a Trout Perch
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Diagram showing electroreception
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