The role of vision for the vast majority of underwater inhabitants is extremely high. Along with other senses, vision allows fish to receive information about the environment, ensure contact between individuals of their species, and also determine feeding activity.
But life in the aquatic environment leaves its mark on the visual ability of fish. Water, having a higher density compared to air, is capable of not only scattering and absorbing sunlight, but also refracting it. Therefore, the optical properties of water do not allow the fish to see far. In clear water, the clarity of vision does not exceed 2 meters, and the ability to distinguish objects rarely exceeds 10 meters.
Do fish distinguish colors and shapes?
At the same time, fish also have binocular vision. But it is only possible in a limited field, where the viewing angles of each eye intersect. It is in this range of viewing angles that the fish not only clearly sees objects and their shape, but also distinguishes colors.
Many fish have an extremely wide range of color perception. Some fish distinguish colors and shades even in the ultraviolet range.
The ability of fish to distinguish colors and shapes is important both from the point of view of feeding and from the point of view of protection from predators. If, for example, flounder were not forced to adapt to the color of the bottom for hunting and protection, would it do this?
What problems will happen if you leave the light on at night?
24/7 lighting in an aquarium will lead to many problems. Here are the most common of them:
- Some fish species will be under stress when exposed to 24/7 lighting. Over time, this will lead to them attacking each other.
- Due to an excess of light, algae will begin to grow in the aquarium. Over time, such a container will begin to look dirty and unsightly. Algae growth will cause plant death.
- Fish, like other living creatures, need darkness to sleep. If they don't rest, they will become inactive.
Is the color of the bait important? What color of bait should you choose?
All colors are perceived differently in water. It depends on the transparency and illumination of the water.
It is known that the deeper it is, the less light penetrates. But in fact, in this context, it is worth saying: “the deeper, the smaller the visible range of color.”
Spectrum of light transmittance in water
From the school physics curriculum, we know that each shade of color is characterized by a certain wavelength of light. The shorter the wavelength, the deeper it penetrates. Therefore, the least universal color, depending on the illumination, will be red. Red and its shades will only be clearly visible in clear and well-lit water. Fans of fishing for red maggots and bloodworms should know this. Although, of course, these attachments also have a smell, which is not affected by lighting.
The visible range of colors for many fish ranges from infrared to ultraviolet. To understand what color a fish sees better depending on the illumination of the water, it is enough to remember the distribution of colors in the rainbow: red, orange, yellow, green, blue, indigo, violet. Of course, this is a figurative perception. There are thousands more shades, and each of them is transitional between the listed colors and is one way or another located in the color scheme of the rainbow.
For those who like to fish at night and at depth, especially under ice, we can recommend baits of various blue and purple shades, as well as baits with ultraviolet glow. But how do you know?
Light travels differently underwater than in air
It all started many years ago when I noticed how color changed underwater. The fundamental conclusion from studies on the absorption of light in distilled water was that with increasing depth, red, orange, yellow, green and last blue are absorbed.
I have discussed this issue at several fishing shows and have to admit that there are some interesting exceptions to the above findings regarding the colors yellow and green. These colors seem to have significantly greater visibility underwater than others. At that time I could not explain this phenomenon.
The brightest colors in ultraviolet light are very good for fishing at great depths. I already knew about the "mysterious yellow and green", but could not find the difference between the different shades of yellow and green. I knew that in clear water blue and violet colors penetrate very deep into the water column, and later I learned about fluorescence and the excellent visibility of these colors under water. Having quickly realized the difference between regular and fluorescent colors, I began using the latter on my lures. It didn't take long to discover that my most catchy lures in low light had high contrast, especially the fluorescent colors. I had a bait that was brightly colored orange-green with a yellowish tint. I decided to test it in Sweden, where the diet of pike includes herring. Believe it or not, the fluorescent orange bait proved to be the most catchable in slightly dark water. All my colleagues were confused because we usually used black-and-white and blue-violet baits for pike, the natural colors of the herring that the pike fed on.
My colleague Jörg found another fluorescent orange bait that also turned out to be very successful.
| Pike on fluorescent orange bait | With orange Jorg is also not without a catch! |
The UV light helped me easily identify the best colors to fish in low visibility, and the lures that didn't look as good under the UV light ended up being my most catchy ones in clear water. Since then, I always have an ultraviolet lamp with me to help me choose the best color bait.
| In daylight | Under ultraviolet light |
I also experimented with the visibility of flowers underwater. I did my first dives in Indonesia. People around me laughed, looking at me diving under the water with a set of baits.
| Original color | Depth 5 meters | Depth 15 meters | Depth 25 meters |
Sea water is generally clearer than fresh water, so I also experimented a bit in the lake at home. The color palette went down to a depth of more than 3 meters. As depth increased, there was a significant change in the visibility of colors.
| Color palette | Depth 1 meter | Depth 2 meters | Depth 3 meters | Depth 5 meters |
Ultraviolet flashlight
If possible, you need to look at the glow of baits under ultraviolet light. There are special ultraviolet lamps for this.
Ultraviolet flashlight. Keitech lures and blue fox spinners in ultraviolet
View in store
The brighter the bait shines, the better it will be visible in low light conditions.
White baits are the most versatile.
Separately, it is necessary to say about the white color. White color includes the entire spectrum of electromagnetic radiation. Along with black and shades of gray, white is an achromatic color. But if black absorbs all color waves, then white reflects. Therefore, white color, from the point of view of choosing bait for different light levels, will be the most universal. This is also true for water clarity levels.
In opaque and muddy water, the color of the bait will play the same specific role. The best choice would be those colors that contrast with the color of the water caused by various factors (algae blooms, precipitation, waves, the nature of the soil, etc.). Of course, a fish can bite even when the color of the bait matches the color of the water, but then other senses will play a greater role.
If fishing takes place in conditions of good lighting and water transparency, then the choice of bait color is not so important. The best choice for active fishing would be the so-called natural colors. They will not distract or alarm the predator. But at the same time, if a predatory fish is passive, then a bright and unusual color can attract its attention. That’s why it’s so important to experiment and change the shapes and colors of baits.
Silence
But, even if the fisherman sits down on the shore, hides and the fish does not see him, silence must be maintained, since in this case the fish feels vibrations along the lateral line, which plays a very important role in the life of the fish. These nuances need to be taken into account by the fisherman and used in fishing. For example, if a fisherman is dressed in bright clothes and immediately approaches the shore, he will be noticed by the fish, and the unusual color will alert him. On the other hand, if you dress in camouflage clothing (in accordance with the time of year), slowly approach the shore, go against the current (since predatory fish often “stand” with their heads against the current), from the tail of the fish, and do not stomp (since vibrations fish catches with a lateral line), then the chances of catching a pike, for example, increase significantly.
Which fish see better?
Different species of fish have different vision. For example, in some deep-sea species, vision may be almost completely absent due to its lack of need in dark conditions. Although other inhabitants of the deep sea, on the contrary, developed special vision and adapted it to pitch darkness. In fish found in cave reservoirs, vision was generally completely reduced.
But from a practical point of view, we are more interested in the vision of “our” freshwater fishing objects.
Pike perch are purposefully caught at night. Photo - https://www.instagram.com/volkifish/
Fish that live in clean and clear water, such as trout, grayling, lenok, asp, pike and some others, see and distinguish colors best. Fish such as pike perch, catfish, burbot, and eel have well-developed night vision. If you shine a flashlight on a pike perch, you can see its glowing eyes. By the way, luminous eyes indicate good night vision in terrestrial animals.
Many active predatory fish have a good motor visual response. Therefore, for protection, some fish form schools and schools (fry), others have developed speed or, conversely, are able to remain motionless. To escape from predators, peaceful fish must see approaching danger from afar, as a result of which any movement of large objects, silhouettes and shadows causes them to react defensively.
Thus, for most fish, vision is an important sensory organ (along with the lateral line), and for some species it plays a primary role.
Freshwater fish vision
Novitsky R. | July 15, 2005
We do not have one hundred percent confidence in exactly how life occurs under the surface of water. We judge indirectly how this or that fish reacts to various stimuli, how it finds the bait and what stops it from taking a decisive bite - by the results of fishing, the presence or absence of “grabs” and escapes, etc., etc. . P.
In order to effectively use their fishing experience in confrontation with the inhabitants of our water bodies, a modern amateur fisherman or sportsman must have a considerable amount of knowledge gained through repeated personal observations or gleaned from reliable scientific sources.
In this article we continue the conversation about the sensory organs of fish and their unequal role in the life of underwater inhabitants (see “SR” Nos. 2 and 8 for 2002, No. 2 for 2003 and No. 2 for 2004).
About the sensory organs of fish
In the history of the development of human civilization, special attention was paid to the study of fish in the 4th century BC. e. In fact, ichthyology as the science of fish began with Aristotle (384-322 BC), who made the first attempts to classify the huge variety of inhabitants of the kingdom of Neptune and described the biology and anatomy of many species of fish.
Over two and a half thousand years, fish have been studied in sufficient detail, but naturalists of the 2nd-19th centuries, who described the underwater inhabitants of rivers, seas and oceans in their scientific works, were sincerely confident that fish are very primitive, stupid creatures that They have neither hearing, nor touch, nor even any memory. By the way, these fundamentally incorrect views persisted in the scientific community until the 1940s.
Currently, almost any “literally savvy” fisherman, not to mention ichthyologists, knows why fish have a lateral line, whether fish can hear or smell, how they find food or sense the approach of a predator...
It is well known that sense organs, or, as they are now commonly called, sensory systems, enable a living organism to perceive a variety of information about the surrounding world, as well as signal about the internal state of the organism itself.
The sensory organs of fish are capable of:
- perceive electromagnetic fields in the visible (vision) and infrared (temperature sensitivity) regions of the spectrum;
- feel mechanical disturbances, or sound waves (hearing),
- feel gravity (vestibular and gravitational sensitivity) and mechanical pressure (touch);
- recognize a variety of chemical signals - perception of substances in the liquid phase (taste) and in the gas phase (smell).
The sensory systems of fish include the visual, auditory, gustatory, olfactory, tactile, electroreceptive sensory systems, as well as the seismosensory system, represented by the lateral line, and the general chemical sense.
One of the most significant sense organs in animals is vision - this is the ability to perceive electromagnetic fields in the visible region of the spectrum.
With the help of visual analyzers, fish navigate in space, find food or avoid predators, occupy appropriate ecological niches, visually assessing the nature of the visual environment (Beur and Heuts, 1973).
Popular information about the structure of fish eyes
Fish see (perceive light) in the aquatic environment with the help of their eyes and special light-sensitive kidneys. The peculiarities of the vision of fish under water are determined by the transparency of the waters, their viscosity and density, depth, current speeds, way of life and feeding.
Compared to land animals and humans, fish are more myopic. The cornea of their eyes is flat and the lens is spherical. It is its shape that causes myopia in fish. In many fish, the lens can protrude from the opening of the pupil, thereby increasing the field of view.
The substance of the lens is the same density as water, as a result, light passing through it is not refracted and a clear image is obtained on the retina of the eye.
The retina of the eye (the inner membrane) has a complex structure, consisting of four layers: pigment, light-sensitive (the so-called rods and cones) and two layers of nerve cells that give rise to the optic nerve.
The role of the rods is to function at dusk and at night, and they are insensitive to color. With the help of cones, fish perceive different colors.
The pupil of almost all species is motionless, but flounders, river eels, sharks and rays are able to narrow and expand it, increasing visual acuity.
Features of vision in different fish
In most fish, eye movements are coordinated, only in some (greenfinch, galkan, sole, etc.) they can move independently of each other. Predatory fish have the most mobile eyes.
In our marine and freshwater fish, the organs of vision - the eyes - are located on the sides of the head, and each eye sees its own field of view. This type of vision is called monocular. In front, the monocular vision of each eye overlaps, creating a zone of binocular vision. The angle of binocular vision in fish is very small - no more than 30?.
The famous American scientist Robert Wood showed how fish can see from the water. According to the laws of refraction of light rays, objects located on land appear higher to the fish than they actually are. If you look from the water towards the shore at an angle to the vertical of more than 45°, then due to total internal reflection from the surface of the water, objects (the fisherman) become visible to the observer (fish). A fisherman standing on the shore appears to her to be hanging in the air and clearly distinguishable, but the fish will not notice a sitting person, since at a small angle of inclination of the rays to the horizon (less than 45?) ground objects are invisible to it.
The vast majority of freshwater fish see a maximum of 1 m. In clear water (for example, in our reservoirs in winter), fish can practically see at a distance of 10-12 m, but they can clearly distinguish objects, their shape, and color within 1-1.5 m. When the eye accommodates with the movement of the lens, the eye is adjusted to a distance not exceeding 15 meters. This is the limit of the fish's visual range.
According to experimental studies, river perch is able to see an object 1 cm in size at a distance of about 5.5 meters. When the size of an object decreased by 10 times, the distance the predator saw it decreased proportionally - the perch saw the object 55 cm away. The predator saw a tiny object measuring 0.1 mm only 5.5 cm away.
Ichthyologists distinguish between light-loving (daytime) and crepuscular fish. In diurnal species, there are few rods in the retina of the eye, but the cones are large. These fish (pike, roach, chub, asp, etc.) distinguish colors well - red, blue, yellow, white. In twilight fish (pike perch, burbot, catfish) there are only rods in the retina, and, therefore, they are not able to distinguish colors and their shades.
The eyes as an organ of vision are well developed in light-loving fish (pike, sabrefish, rudd) and some crepuscular species (bream, ruffe, silver bream, burbot). In other twilight fish (bottom fish) - carp, crucian carp and tench - the eyes are less developed (Protasov, 1968). In this regard, in light-loving fish, orientation and search in space, feeding can be carried out mainly through vision, and in crepuscular fish - mainly thanks to the organs of touch and other sensory systems.
In pelagic planktivores (silver carp, saberfish), food search is carried out almost entirely through vision.
The ability of fish to distinguish colors. Daytime fish distinguish colors quite well, at least spinning anglers know this, using a white vibrotail or a white-red twister in hunting for pike or perch in different lighting conditions. The Black Sea anchovy, against the background of blue-green water, distinguishes (sees) nets of different colors at the following distance: blue-green - 0.5-0.7 meters; dark blue - 0.8-1.2 m; dark brown - 1.3-1.5 m; gray or black - 1.5-2.0 m; white (unpainted) - 2.0-2.5 m.
Twilight and nocturnal fish, as noted above, are not able to distinguish colors, so sports fishermen and amateurs, when experimenting with baits, should pay special attention not to the color of the bait, but to its behavior (drag, noise characteristics).
The use of specially brightly colored baits for catching twilight predators (the same pike perch or catfish) seems to the author unjustified, since this fish does not react to the color of a certain “Predator”, but only to its hydrodynamic qualities, correcting the upcoming throw with vision (thanks to the excellent twilight - black - white - vision) outline of the bait. Moreover, the brighter its silhouette against the background of a bottom strewn with stones (white on black, fluorescent on black), the greater the number of grips and catches of a predator a spinning angler will notice when using the same baits, but different colors. And again, the white or yellow color of the bait will be decisive for the cast of the pike perch, and certainly not purple, for example, stains on the green background of the wobbler (unless, of course, it is a super-irresistible, rattling-ringing model)...
Visual perception of movements by fish. Russian scientists studied the ability of the visual apparatus of fish to perceive movement. To do this, we observed the optomotor reaction of fish to sequentially moving stripes or details of the situation for 1 second (determining the magnitude of optical moments). The following results were obtained.
The optical moment for verkhovka and crucian carp was 1/14 - 1/18 seconds, pike and tench - 1/25 - 1/28 s, bream and perch - 1/55 s. Fish with optical moments from 1/50 to 1/67 s are capable of perceiving the same movement in twice as much detail as humans, and fish with optical moments of 1/10 to 1/14 are able to perceive the same movement in half as much detail.
The subtle perception of movement by the visual apparatus of fish allows the victims to catch the initial moment of the throw and escape from the predator. For peaceful fish, the signal of the impending attack of a predator is the twitching and vibration of the dorsal and pectoral fins, as well as the entire body of the hunter, captured by the eye of the potential victim (Protasov, 1968).
Well-fed and tired fish have a weakly expressed optomotor reaction (reaction to movement), while hungry and well-rested fish have a strongly expressed reaction.
Sense organs of fish in the feeding behavior of fish
Also of interest to fishermen are the experimentally obtained and tested results in natural conditions of the alternating functioning of the sensory organs of fish when they search for food objects.
During the “free search”, when the distance to the food object exceeds 100 m, only the fish’s sense of smell “works”, the rest of the sensory systems are not involved. When approaching the source of a “delicious” smell from 100 to 25 m, hearing is connected to the sense of smell. At a distance of 25 to 5 m, the fish tries to find food using smell, sight and hearing.
When food is just a stone's throw away (from 5 to 1 m), the fish primarily uses vision, then smell and hearing. At a distance of 1 to 0.25 m, the search simultaneously involves vision, hearing, lateral line, smell, and external taste sensitivity (feeling the ground with antennae, touching with lips, snout, even fins).
When food is “under the nose” and the distance to it does not exceed 0.25 m, the fish “turns on” almost all senses: vision, lateral line, electroreception, external taste sensitivity, general chemical sense, touch. Their joint work quickly leads to the fish finding food.
Behavior of predatory fish depending on visual characteristics
In relation to the period of greatest feeding activity, the following division of predatory fish is used: perch - twilight-day predator, pike - crepuscular, pike perch - deep-twilight.
Ichthyophagous perches and pike feed around the clock: during the day they hunt for prey from ambush, at dusk and dawn they go out into open water and pursue victims. “Twilight” feeding of predators occurs at illumination from hundreds to tenths of lux (in the evening) and vice versa (in the morning). During this period, perch and pike have daytime vision with maximum sharpness and range of vision, and dense schools of prey fish begin to disintegrate, ensuring successful hunting for predators. With the onset of darkness, individual fish disperse throughout the water area; when the illumination drops below 0.01 lux, the top and bleak sink to the bottom and freeze. The hunting of predatory fish stops.
In the pre-dawn hours, with illumination ranging from tenths to hundreds of lux, the “bashing of the babies” continues until the moment when the prey fish form dense defensive schools.
According to research by ichthyologists, in summer the duration of the morning feeding of predators reached 3 hours, the evening - 4 hours and the night (pike perch) - 5-6 hours.
Pike perch can use their vision in conditions where other fish cannot see. The retina of a predator's eye contains a highly reflective pigment, guanine, which increases its sensitivity. The hunt of pike perch for small schooling fish is most successful in deep twilight illumination - 0.001 and 0.0001 lux.
In autumn, in cloudy and rainy weather, when the light changes slightly, young peaceful fish form sparse defensive schools and predators can successfully hunt throughout the day, and not just at dusk. The so-called “autumn gluttony” of the predator occurs.
An interesting feature of pike and perch hunting in the light and with high water transparency was noted. During the daytime, these fish act as typical ambush predators: if they fail to capture prey from an ambush, they do not pursue it, so as not to scare away other potential victims from the hunting site. Those areas where a predator is hiding, having discovered its hiding place with excitement, are avoided by schools of fish. Therefore, during the day, a pike or perch makes a well-calibrated and accurate throw only if it is possible to 100% capture the prey. Vision plays a decisive role in a successful throw.
Thus, knowing about the characteristics and capabilities of visual perception of fish, fishermen have the opportunity to carry out a targeted search in a reservoir for a future underwater “sparring partner.” Knowledge of the enemy’s strengths and weaknesses (read: the visual capabilities of fish in sea and fresh water, during the day and at dusk), I hope, will help numerous fishing fans emerge victorious from this most exciting and fair fight...
Smell and taste of fish
Nose of a fish with four nostrils . But the most important for fish, of course, are the senses of chemoreception, namely smell and taste. Again, people once believed that olfactory receptors could only analyze gaseous substances, and therefore fish lacked the ability to smell. How cruelly they were mistaken!
In our understanding, fish smell with their noses . The paired olfactory organs of fish have two openings each - for the entry and exit of water. That's why they have two nostrils on each side - so that water can circulate freely through the cavities lined with sensitive cells. Water, directed by special valves, usually simply flows into the nose as you move. But fish can also sniff intently, expanding and contracting their olfactory sacs, moving their nostrils - just like a hunting dog smelling prey. Special cilia lining the cavity of the sacs can also drive water through the nose. The sense of smell plays a different role in the lives of certain species of fish. There are some representatives that, when hunting or searching for food in bright light of day, rely primarily on vision, for example, pike. Twilight fish, in turn, are guided primarily by either taste (carp, tench) or scent (catfish, eel).
As for taste, the fish understands very well what it eats . Although many of us still believe that the sense of smell and taste of these underwater inhabitants are the same sense, since they have to live in water. But one cannot replace one with the other: completely different receptors react to the taste and smell of fish, and completely different lobes of the brain are responsible for their perception. Olfactory receptors are in the nose, taste receptors are in the mouth, what’s incomprehensible here? Everything here is like with people. In addition, the taste buds of some fish are also located on the lips, antennae, cheeks, head and even on the sides! Fish also perfectly distinguish taste - bitter, sweet, or salty.
Also, the most important sensory organ in fish, especially in complete darkness, is the lateral line . This is a full-fledged organ that responds to the slightest fluctuations in water. With its help, the predator senses the movement of the prey in the grass, and the victim senses the careful movement of a creeping predator; the fish feels the powerful current, the light whisper of waves hitting the shore, the biting blows of the wind on the surface of the lake and the cheerful drops of mushroom rain. By the way, the predator also senses vibrations of fishing lures with its lateral line, and in very muddy water, even those that have practically no game of their own, such as foam rubber lures.
Test: what kind of Pisces are you?
A zodiac sign in its pure form usually does not determine all the character traits of each individual person; the whole horoscope will give a big picture, however, representatives of certain zodiac signs, no matter how skeptics argue, still have similar traits.
If you are a representative of the Pisces sign, we suggest you take an interesting test that will tell you more details
about your sign.
By the way, representatives of other signs can also try to take the test and find out what kind of fish lives in their inner world and how it affects their character.
Look carefully at the pictures and choose the one you like best. Record your points
, which correspond to each of the pictures, add them up and get your result!
So, let's begin…
1) Look at the fish: which picture is closest to you?
viewbug y-studio yrabota southpict
2) Which sea would you be more interested in swimming in?
den-belitsky aubreefulhamphotos John_Walker blueorangestudio
3) Choose a fish dish or seafood dish that you would like to try right now!
gbh007 Oleksandr Prokopenko AlexPro9500 kstudio
4) Question number 4. What kind of fish do you dream of catching?
demarfa Rui Dias Lunamarina tatyana_tomsickova
5) Question number 5. Choose the talisman you would like to have.
Naira1962 Prensis VladyslavDanilin EpicStockMedia
Add up all the numbers of the selected pictures and see the total points:
- If your score is from 5 to 7, you are a Gentle Fish
You can call yourself a typical representative of the Pisces sign! This fish is quite vulnerable and often does not know how to withstand difficulties, preferring to shift responsibility to others. But you are driven by inspiration, you intuitively know how to choose a path and attract good people into your life.
- The total score is from 8 to 12, which means you are a Piranha Fish
Number 2 is piranha. You are a strong representative of your sign and know exactly what you want, unlike many other Pisces. You know how to give up temptations and bad habits that get in the way when you go towards your goals. Despite the fearsome image of the piranha, you are not a predator, but you can be very selfish. By the way, you have talents for the occult and can develop very strong energy abilities.
- Does your sum correspond to a number from 13 to 17? Then you are a paired fish
If you are a couple fish, you most likely have a strong need for partnership. You are a fish that always exists in pairs and cannot imagine your life completely alone. If you don’t have a partner now, it’s only because you are looking for a worthy one and, most likely, you will find it very quickly. Your partners inspire you, and you are ready to move mountains for your love.
- If you score the maximum number of points - from 18 to 20, then you are a Beautiful Fish
You are not an ordinary fish, but a magical one! You feel and understand the laws of nature, have a very developed intuition and know how to use it all for the benefit of yourself and your loved ones. You often dream, fantasize and realize that your dreams very quickly become reality. Sometimes you even play these “fantasy” games: imagine a vivid development of events, and then watch how it all comes true. If you start practicing mysticism, you will make very big discoveries for yourself!
Join astrologer groups infoniac.ru, follow the most interesting news, get answers to your most pressing questions in a personal consultation:
Where do they do this?
The inhabitants of the aquarium sleep in different ways, but there is one common feature - their activity becomes minimal. Some fish simply “hang” in the water, others cling to leaves or branches of plants.
There are also those who make themselves more comfortable on their sides or abdomen, sinking to the bottom. There are also those who like to sleep with their belly up, frozen upside down and even buried in the sand.
From the editor: Nitella or Blestyanka flexible
This mainly depends on the presence of a swim bladder, that is, that organ that contains air and allows fish to rise to the surface of the water, stay in its thickness, or sink to the bottom. This way, the inhabitants of the aquarium have the opportunity to remain at a certain depth even during sleep.
However, not all fish have a swim bladder, which means they need to be constantly moving to avoid sinking to the bottom. It would seem like a good option, but the gills of such individuals are designed in such a way that they can only receive oxygen by moving.
Therefore, fish are forced to move even in their sleep or find places with a bottom current that will self-wash their gills. Among aquarium fish there are few of these - loaches, ancistrus and catfish.
When setting up an aquarium, you need to take care of places for sleeping: plant algae, arrange figurines, put driftwood and stones.
“Hanging” of a fish in a strange position can be associated not only with sleep, but also with illness. Therefore, when such behavior is observed in a pet for the first time, it is better to knock on the glass near it and observe the reaction. If he returns to his normal activities, everything is fine.
Using the Right Colors Gets Results
There are many questions and speculations about flowers underwater, and it took me a long time to understand this issue through research and underwater testing.
The first most important question that interests the fisherman is what does the fish see underwater? Can she see colors? Is it possible to distinguish colors underwater? These and similar questions occupy the minds of all anglers who use artificial bait, and I am no exception!
Editorial: Copadichromis cadango
So, to understand the process of color perception under water, it is necessary to answer two questions:
- What color can a fish's eye reach?
- Which of these colors can a fish distinguish?
