Fishes and their habitat. External structure of fish: description, features. Shallow water zone, or continental shelf

The littoral zone is a place where there are almost no fish, since it is not yet a “full-fledged” body of water, but the border between the coast and the tidal zone. Therefore, only some fish risk entering the littoral zone. These include, in particular, mudskipper, which stores water behind its cheeks and can get out even further than the littoral zone, climbing trees and intertwined roots. During high tide, jumpers often sit on tree branches, clinging tightly to them with their fused ventral fins. There are 10-12 species of these fish, which have a head resembling that of a hippopotamus, with bulging frog eyes.

They travel overland in search of earthworms and other living creatures - slider fish, oblong, reaching 15 cm in length. California gillicht gobies live without water in a damp, cool place for several days. Eels can crawl on the ground and outside the littoral zone, moving to other bodies of water if necessary. Some fish, e.g. blennies sphinxes, when thrown out by the tide, can sit for a short time in the littoral zone, waiting new wave. Protoptera, lepidosirene and cattail, can live for some time without water in the littoral zone due to the presence of special lungs. Some polyfins can crawl out to the littoral zone and “travel” along it. Juvenile flag-tailed shorebirds prefer to stay in the pools formed by the tide. Only at the border of the littoral zone and the continental shelf is there constant water; there are small fish such as blennies, small catfish, greenfinches, needle fish, some coral fish, as well as lungfish and some cartilaginous ganoid fish.

Shallow water zone, or continental shelf

Shallow water area, or continental shelf- habitat of important commercial fish: sturgeon, sprat, anchovy and many others. Herring, mackerel, tuna and other fish often come here during times of abundance of food. Among small fish of temperate waters, first place in total mass occupied by anchovies, for which predators come: cod, sharks. In this zone, young fish of many species live their childhood. Grunion silverside fish, living in schools in the shallow waters of Mexico and California, breed in the littoral zone, burying their eggs in the sand at the water's edge during high tides. At low tide, the eggs develop in the warm, wet sand. In other species of silverside eggs, the eggs have thread-like appendages with which they are attached to some substrate.

Among the fish of the continental shelf, there are also sucker fish, in which the fused pelvic fins form a sucker, allowing them to cling to coastal stones even during strong waves. Many fish that do not have a special commercial value: dogs, greenfinches, "cockerels".

In Australia, dangerous fish also live in the continental shelf zone: for example, sand and great white shark. Other sharks found in shallow water include the hammerhead shark, herring shark, and blue shark, but there are also harmless species like the leopard shark and catshark.

Coral Reefs: A Zone of Super-Rich Seas

Coral reefs are an area where all the brightest, strangest and funniest fish are gathered in one heap. Only on one Big barrier reef you can find one and a half thousand species of fish of the most diverse shapes and colors, from clownfish to ragpickers.

Coral reefs have been formed for many millions of years in shallow areas of warm waters near the Antilles and Sunda Islands, not far from Australia, Africa, Madagascar, and Sri Lanka. Tiny skeletons coral polyps gradually layered on top of each other to form coral islands.

The reef zone is home to many planktivores and herbivorous fish, which attract many predators, and among them a large proportion are cartilaginous fish.

The entire community of animals and plants of coral reefs is divided into several environmental groups. Thus, parrot fish, whose teeth are very similar to an arched beak, which is extremely convenient for biting off pieces of coral and algae, are destructors, that is, destroyers of corals. Among other destructors it is widely known Starfish"crown of thorns"

Let's now talk about the simplest of all types of relationships between fish - predator-prey relationships. There are a lot of predators here on the reefs! This is especially true for sharks. The most common are the so-called reef sharks. There are sand sharks, white sharks, spiny sharks, and herring sharks. There is even a carpet shark, which, like scorpionfish and monkfish, flat and disguised by growths! "Sea Shadows" are always ready to grab a wounded or unwary fish. Of the stingrays there are stingrays, various electric ramps and sawfish. But next to these dangerous fish swim their harmless relatives - manta rays (as discussed in Chapter 3, they can only harm a person if they accidentally fly into a boat).

There are also bony predators. These include barracudas, moray eels, scorpionfish, anglerfish, and groupers - there is no room to list them! They can send to better world most of their “neighbors” on the reef - except for larger fish.

I did not talk separately about the fauna of the bottom zone, since it is similar in fauna to the reef zone. However, there are also some interesting fish. For example, a common bug from the order Percopsidae. A curious way is how it buries itself in the sand: swimming head first near the bottom, it abruptly goes into reverse and, sticking its tail into the sand, quickly sinks completely into it, working with its fins. There are also many unusual species of eels.

Fish are the largest group of vertebrates. It includes about 30 thousand modern species. Fish are divided into two classes - Cartilaginous fish (sharks, rays) and Bony fish(sturgeon, salmon, herring, crucian carp, perch, pike, etc.). The main criterion for this division is the substance of which the internal skeleton of fish consists - cartilage or bone.

Fish inhabit various bodies of water on our planet: oceans, seas, rivers, lakes, ponds. The aquatic environment is very vast: the area occupied by the oceans exceeds 70% of the Earth's surface, and the most deep depressions They go 11 thousand meters deep into the oceans.

The variety of living conditions in water influenced the appearance of fish and led to the emergence of a wide variety of forms: the emergence of many adaptations to specific living conditions (Fig. 115).

Rice. 115. Fish of various ecological groups: 1.2 - tuna and cod living in the water column (pelagic): 3 - surface flying fish; 4 - bottom flounder

In fish, the laterally compressed body has a streamlined shape. In it you can distinguish the head, body and tail.

The outside of the fish’s body is covered with skin containing small (like perch) or large (like carp) bony scales. They overlap each other in a tiled manner and tightly cover the body and tail. The scales are constantly growing, and annual rings are formed on them, from which the age of the fish can be determined (Fig. 116, B, C). There are fish and bare-skinned ones without scales (for example, catfish). The body of fish is slippery, as it is covered with secretions of mucous glands located in the skin. The scales are painted in silver-gray and black tones. Many fish are characterized by bright colors, especially those that live among coral reefs.

Rice. 116. External structure fish: A - general plan of the structure: 1 - nostril; 2 - eye; 3 - mouth; 4 - gill cover; 5 - pectoral fin; 6 - ventral fins; 7 - dorsal fin; 8 - anus; 9 - anal fin; 10 - lateral line; 11 - caudal fin; B - scales with annual rings; B - determining the age of the fish

Fish have limbs - unpaired and paired fins. Unpaired are the dorsal, caudal and anal, or subcaudal. The most important of them is the tail one. It serves as the main motor organ - with its help fish move forward. Paired fins are located on the sides below: the anterior ones are pectoral, the rear ones are abdominal. The pectorals are more mobile, they are involved in turning the body in the water, moving up, down and to the sides. Pelvic and unpaired fins hold the fish's body in a normal, vertical position. Behind the pelvic fins three openings are visible: anal, genital and urinary. Undigested food remains are expelled through the anus, and through the urinary harmful products vital activity, reproductive products are released through the sexual system: eggs in females and seminal fluid in males.

On the sides of the fish's body there are lateral line organs - channels lying in the skin under the scales, at the bottom of which there are sensitive cells that perceive water vibrations. These organs allow the fish to perceive the flow of water flowing around the body and to distinguish objects thanks to the waves that emanate from these objects.

Other sense organs are located on the head. The border between the head and the body is considered to be the posterior edge of the gill covers (see Fig. 116, A). They cover the gills and constantly move, providing a flow of fresh, oxygen-rich water to the gills. The boundary between the body and tail is conventionally drawn at the level of the anus.

The mouth is visible on the front of the head. With its mouth, the fish grabs food and draws in water necessary for breathing. Above the mouth there are nostrils that open into the olfactory organs, with the help of which the fish perceives the odors of substances dissolved in water. The eyes of fish are quite large. The front side of the outer shell (cornea) is flat. Underneath it is a convex lens (lens), which gives a reduced image of objects on the retina, the cells that perceive light stimulation. Pisces see on close range and distinguish colors.

The hearing organs are not visible on the surface of the head: they are located on the sides of the head inside the skull. Sound waves in water, the fish perceives with the entire surface of the body. These vibrations cause irritation of the nerve endings of the inner ear, and the resulting excitations are transmitted along the auditory nerves to the brain. Next to the inner ear there is an organ of balance, thanks to which the fish senses the position of its body, moving up and down.

Laboratory work No. 6

Subject. External structure and features of fish movement.

Target. Study the external structure and methods of movement of fish.

Equipment: jar with fish in water, magnifying glass, glass slide, fish scales.

Progress

1. Examine the fish in a jar of water. Explain the significance of her body shape.
2. Consider the coloring of the fish's body on the ventral and dorsal sides. If it is different, indicate the reasons for these differences.
3. How are scales located on the body of a fish? What does this mean for the life of fish in water? Using a magnifying glass, examine the structure of an individual scale.
4. Find the parts of the fish's body: head, body, tail. Set their boundaries. Explain the importance of smooth transitions of body parts for the life of fish in water.
5. Find the fish's nostrils, eyes, and lateral line. What is the importance of these organs in the life of a fish? Find out what is special about the structure of the eyes.
6. Examine the fins of the fish. Which of them are paired, which are unpaired. Observe the action of the fins as the fish moves through the water.
7. Sketch the fish in question. Label the parts of the body in the drawing. Draw a conclusion about the fish’s adaptability to life in water. Draw a picture of fish scales, marking the light and dark stripes. What is the age of the fish from which this scale was taken?

Fish are well adapted to life in the aquatic environment. They have a streamlined body shape, fins that provide movement in the water, and sensory organs that allow them to navigate in the water.

Exercises based on the material covered

1. By appearance determine the habitats of the fish shown in Figure 115 (p. 10).
2. What structure do the body covers of fish have and what is their significance in the life of fish?
3. What sensory organs do fish use to navigate in the water?
4. Name the fins of the fish and describe their functions.

It is impossible to describe all the countless habitats of fish, ranging from small streams and ponds to vast oceans. Therefore, we are forced to limit ourselves to three main types of fish ecosystems: lakes, rivers and seas. In addition, there are many intermediate fish habitats that we do not stop at. Our main focus now is on geographic zones with temperate climates.

Lakes

Lakes can be classified different ways. Here we rely on their ability to reproduce organic matter. Oligotrophic lakes are nutrient-poor, relatively deep, and contain few living organisms. Eutrophic lakes, rich in nutrients and quite shallow, are the source of rich organic life.

The productivity of a lake is determined primarily by its basin, that is, the place of drainage or precipitation collection, as well as climate. As a rule, most oligotrophic lakes are located in areas with insignificant ancient rock deposits, and the majority of eutrophic lakes are located in regions rich in limestone. Lakes in densely populated parts of the Western world are becoming increasingly eutrophic, constantly receiving nutrients from municipal and farm runoff. This ever-increasing influx nutrients, as we will soon see, poses a serious threat to salmonids, although at present such conditions are quite suitable for the so-called eutrophic species, mainly the numerous cyprionids.

Life in the lake

The life of animals and vegetation in the lake largely depends on the availability of food in it. Both the number and diversity of living organisms differ significantly in eutrophic and oligotrophic lakes. However, both of these types of lakes have common biotic features.

Plankton - This is a large group of tiny organisms floating in water, whose movement is more or less dependent on the current. This applies to a greater extent to plant species (phytoplankton), while animal species (zooplankton) are more active swimmers. The bulk of zooplankton lives in the free waters of the lake, which are called the pelagic zone. Some of them, such as copepods and cladocerans, perform vertical diurnal migrations, rising to the surface of the water at night and returning to the depths during the day. This migration phenomenon has not yet been explained, but is probably related to sunlight. As we will see, plankton is the main food for almost all juvenile fish, as well as for many species of adult fish.

Nekton usually involves swimming organisms, particularly the strongest of them, which can change the direction of their swimming at will. Mainly these are fish, of course, but also some other organisms such as crustaceans and waterfowl, which are also classified as nekton.

Benthos - This is a group of organisms that live or rest on the bottom. They live in bottom sediments or are connected to the bottom by some other conditions of their life or nutrition. In the coastal zone of lakes, the environment is very diverse, intense and requires special adaptation. For example, species living on areas of steep, wind-exposed, rocky bottoms must be able to withstand mechanical pressure. Like many river animals, they often have quite flat body, and sometimes claws, suckers or rough pads on the limbs. In contrast, individuals living in a calm lagoon with a clay or muddy bottom can be quite fragile. They only need to inhale enough oxygen to compensate for the lack of it that often occurs in such places. Thanks to photosynthesis, such protected environments are usually highly productive in terms of vegetation. Its benthos is often very diverse and includes worms, mollusks, crustaceans and insects at various stages of development.

The coastal zone of the lake is richest in species diversity. As you move deeper, the number of species decreases due to greater depletion of habitat.

In a eutrophic lake, benthos consists mainly of root vegetation in the coastal zone. The shallows of this zone are inhabited by heliophytes - light-loving vegetation with long stems, with their upper parts directed towards the surface. Next to them there are rooted plants with floating leaves, whose flowers barely reach the surface of the water. Next are the bottom root plants, completely hidden under water. This deep-sea vegetation is not usually found in eutrophic lakes, but is great importance for oligotrophic reservoirs.

Food chains in the lake

The main food producers in lakes are green algae. They use their chlorophyll to produce nutrients through photosynthesis from solar energy, carbon dioxide and water. In a certain sense, they feed themselves, but still depend on external feeding. Among other things, they need bacteria to decompose dead matter and thus provide them with basic food supplies. Therefore, bacteria should be considered as the basis of the food web in lakes.

Green algae represent the first cell of this network. They are followed by herbivores - the main consumers who have to choose between living and dead plant materials. We hardly know what they prefer. Herbivorous organisms living at depths where there is not enough sunlight to grow green algae must naturally feed on dead matter that falls there from the surface. They may also constitute the main diet of herbivores in the coastal zone.

Food chains in a temperate lake. These chains do not necessarily lead from primary consumers to final consumers. Due to their close relationships, they often form complex food chains in their environment.

A detritus
b mayfly larvae
With coastal algae
d phytoplankton
e coastal plants
f shellfish
g rotifers
h cyclops
i Daphnia
j water donkey
k bloodworm
l freshwater snails
m horseleech
n mayfly
O perch fry
R trout
q perch
r pike

The third cell of the food web consists of carnivores that eat herbivores. Other animals feed on them, mainly fish, which represent the fourth cell, etc. Any simple sequence of organisms within this network is already a food chain, but the diet of most organisms covers several food chains, which are intertwined in a complex way, sometimes into a very intricate food web. This pattern can also change over time: for example, when young, most fish feed on zooplankton, then switch to bottom dwellers, and some, like carp, can feed on algae as adults.

Where do the fish live in the lake?

Fish occupy almost all habitat niches, or biotopes, of the lake, but the main number of species and individuals are located in the coastal zone. Naturally, plankton-eating fish such as whitefish, which live mainly in pelagic waters, are much less attached to the coastal zone than, for example, trout, whose main source of food is located there.

The picture shows a “fictional” lake, on which the most likely habitats of fish are marked: (a) the confluence of a stream, river, (b) a swampy shore, (c) a cape, (d) the source of a stream, river, (e) overhanging trees, (f) boulders at the bottom.

As in the sea, the habitat of fish in a lake is determined by many factors. Water temperature is often of great importance. This forces fish such as pike, which are relatively well adapted to cold water, remain in shallow waters in the spring and fall, but move to cooler, deeper waters in the summer. They say that perch loves warmth and stays in the warmest places or layers of water in all seasons, even if the temperature difference is only a few tenths of a degree.

It is stated that trout live mainly in the coastal zone, and we are likely to find them there at any time of the year, unless, of course, our definition of this zone is too narrow.

Flowing reservoirs

Depending on the size and volume, water flows are divided into streams, rivers and rivers. In terms of speed of water flow, they are classified into backwaters, rapids, waterfalls, etc. A backwater is an area of ​​more or less standing water between streams or fast streams. We also distinguish upstream stream or waterfall, meaning its beginning, and the bottom
flow - end.

The area from which water flows into a river is called catchment area. Watershed - these are the elevations separating different catchment areas. The volume of water flowing per unit time through any section of a waterway is known as water consumption. It is usually measured in cubic meters (thousands of liters) per second. Water flow per unit of catchment area is called river flow, usually measured in liters per second per square kilometer. Water level - this is the height of the water surface in relation to a specific mark and is measured with a special instrument with a centimeter scale.

Life in the water stream

As mentioned above, in lakes the role of the primary producer belongs to plankton. However, the water flow does not create the most favorable conditions for the existence of these drifting organisms. The plankton found here is usually carried by water from lakes or slow-moving (standing) bodies of water.

In fast-flowing water streams, green vegetation mainly consists of mosses, lichens and algae covering the rocks at the bottom. Only in calm areas of streams or rivers can you find more developed aquatic plants that influence primary reproduction.

Despite this, the process may be even more intense than in any other known ecosystem. The reason for this phenomenon lies in the fact that the flow of water constantly brings the substances necessary for these organisms and carries away their decay products. This efficient exchange allows these organisms to produce much more than would otherwise be expected.

At the same time, water flow creates extreme and stressful conditions to which various organisms often have to adapt. The flattened bodies and claws that allow insect larvae to cling to the rough surface of stones are of much greater importance here than in their counterparts living along the shores of lakes. Many river insect larvae, such as stoneflies, have flattened bodies, although it is not known whether this is due to adaptation to water pressure or the need to hide in cracks to escape the flow of water.

Rivers temperate zone are born high in the mountains and flee to the seas, where fresh water mixed with salty. (1) The cold and oxygenated water of the source flows down often along a rather rocky bed. Animals have adapted to these conditions: they swim well, like salmon and trout, skillfully use areas of calm water, like a goby, etc. (2) Downstream, the depth increases and the strength of the flow weakens, there is still enough oxygen in the water, and rocky The bottom is covered in some places with sand and gravel.
(3) In the lower half of the river the bottom is mostly sand and gravel and the flow is much slower. Perch and eel are often found here. (4) In its lower course, the river resembles more of a pond, where muddy water flows slowly along the muddy bottom. There is a wide variety of plant and animal life all around. Most fish move slowly and have high profile bodies, such as carp and the most famous predator - pike.

Other adaptive changes in animals that are at risk of being swept away by fast currents include a reduction in the size of protruding body parts, such as in mayfly larvae. Some types of articulated animals are held in place by a secretion secreted by the salivary glands. The danger of being washed away by water can also be reduced by using weight or load - for example, some larvae make “houses” for themselves out of sand and pieces of gravel. Fish also adapt to the strong pressure of the water flow, so species living in rapids usually have the most streamlined body shapes.

Organic demolition

The drift of living and dead organic materials in a stream of water is known as organic drift. It is a mixture of insects and their larvae that have fallen to the surface of the water, plankton washed away from lakes, organisms carried away from the bottom, etc. These organic substances are partially consumed by a certain type of organisms called filterers. They obtain food from drifting fauna, using various catching devices for this. Quite simple in some species, in others they can be quite complex, for example, networks with such small cells that they can even trap bacteria! The greatest drift of organic matter usually occurs from lakes and other bodies of water with slow-moving water. There are also the maximum number of filter feeders and, accordingly, more crustacean predators that feed on them. Thus, drift, filter feeders and predators “work together” to form a food chain as efficient as a factory. The particles of nutrients contained in the water, as a rule, are too small to interest the fish, are retained by filter feeders, and when they come off the bottom, they accumulate in predators.

On the diagram of the river section and its sections with different currents, the places where fish usually accumulate are marked: (a) deep pool, (b) weak surface current, (c) calm surface area, (d) fast bottom current, (e) shallow fast current, (f) the beginning of a stream with a calm current.

Since this process occurs mainly at the outlets of lakes, these areas of water flows are very productive and are popular with fish and, naturally, anglers. In fact, many river fish use this drift as well as filter feeders. Instead of chasing prey, they choose a strategically advantageous place in the stream and grab everything that floats past. This behavior in the water flow is characteristic, for example, of young salmon, river and rainbow trout, as well as, to some extent, grayling and char.

Fish habitats in water streams

Most species of freshwater fish can be found in water streams. Many of them live in both lakes and rivers. Moreover, all these fish live in their own specific territory.

Some fish that live in fast (flowing) streams are anatomically adapted to them. As a rule, they have a fairly streamlined body. Salmonids, such as trout and grayling, are adapted to fast currents in many ways, although grayling usually prefers calmer places than trout, which resemble salmon in their habits. Other species, for example, gobies and catfish, stick to the bottom and seek refuge behind or under rocks. Carp and pike usually live in calmer areas of rivers and streams.

The habitats of fish in running water are not determined by any strict rules, since the species themselves and their ability to adapt create a lot of variation. Possible trout habitats in sections of the river with different flow rates are shown below.

Food chains in the sea resemble similar connections in continental lakes, but are more dependent on plant photosynthesis. Here, numerous food chains also intertwine and form a complex food pyramid. Zooplankton is of great importance for nutrition.

A detritus
b brown seaweed
With phytoplankton
d mussels
e scallop
f bivalves
g sea ​​snails
h- P zooplankton
O crabs
R sea ​​stars
q flounder
r shrimp
s herring
t bulls
And cod
v shark

Sea

Thanks to the vast area of ​​the world's oceans and its average depth, which is approximately 3800 meters, marine organisms have a much larger living space than their continental counterparts, which are usually limited to their habitat. Yet the marine fauna is comparatively poor in species: the seas are home to about 160,000 of the million known animal species on earth, two-thirds of which are insects that you won’t find in the sea.

Like lakes, seas have different zones.
Pelagic zone open water space is practically divided into two zones, or regions. Neritic(coastal) zone, including the waters of the continental shelf to depths of approximately 200 meters, beyond which the oceanic the zone, roughly speaking, corresponds to the coastal zone of lakes. Greatest variety environment characteristic specifically for the neritic zone with its shores, areas overgrown with seaweed, estuaries, shallows and coral reefs southern seas, etc., as well as numerous species and varieties of fish.

Life of the sea

Animals and plants found exclusively in the pelagic zone - among them approximately 200 species of animals and almost all microscopic algae - are classified by biologists as holopelagic species Organisms that live primarily in the pelagic zone but spend some stages of their lives on the bottom of the benthic zones are called meropelagine. This group includes about 1,000 species of animals, such as jellyfish.

Between meropelagic animals and real ones benthic species have many transitional forms. For example, adult herring live in pelagic conditions, but the eggs they lay mature on the bottom. Cod lay their eggs in pelagic waters but lead a benthic life. Even flounder and other flat fish initially develop in the pelagic zone. This is practically where most benthic marine animals go through the embryonic stage of their development.

Marine organisms, like lake organisms, are divided into plankton and nekton. Almost all primary reproduction in the sea depends on phytoplankton (algae). The most important type of phytoplankton, in addition to diatoms, are flagellates. They also live in lakes and provide one of the main types of microscopic food for crustaceans, which, in turn, feed on herring. Flagellates are famous for appearing in huge numbers, especially in tropical seas, where their brown-red shells color large areas of the water and form the so-called “red current”.

The main marine zooplankton are crustaceans such as copepods Calanus finmarchicus. It is probably the main type of animal food on earth, living in almost all oceans, from their surface to depths of 3000 meters. In addition, this krill is an unsurpassed filter feeder of microscopic algae, and is therefore of paramount importance as a source of nutrition in the sea. Marine nekton consists of fish cephalopods(squid, octopus, cuttlefish), mammals and birds.

The various habitats of marine animals along this coastline have been created by the movement of wind and water. Among them, three main types can be distinguished. (1) Consisting of rocks, large stones and gravel Rocky coast, which is hit by waves. It provides different habitat niches for plants, fish and other animals, depending on the depth.

(2) On shallow beaches subject to the constant influence of tides, animal life must be adapted to the harsh conditions associated with long dry periods or winds blowing from land.

(3) Further afield, near the mouth of the river, the environment is more sheltered and the beaches are often covered with sand or clay with some rocks interspersed.

While the number of pelagic species of marine animals is only about 3000, benthic species number approximately
150,000. They live mainly in coastal areas at depths of up to 200 meters. The diversity of life forms in the seas of the Arctic and Antarctic is much poorer than in tropical seas. This distribution of species is largely determined by temperature, which in turn depends on geographical latitude and large ocean currents.

Fish habitats in the sea

Marine organisms appear to have an unlimited ability to adapt to their environment. Fish are found at almost all depths, although the number of their species and individuals is much greater in coastal waters. This zone provides them with a wide range of environments from coastal areas, seagrass beds and estuaries to offshore shallows. The specific habitats of marine fish depend, in particular, on the depth, salinity of the water, current and bottom (substrate) structure. The clearest examples of this are flounder, whose body has adapted to a bottom-dwelling lifestyle, or mackerel and tuna, whose torpedo-shaped bodies allow them to develop high speed and dive to great depths. In general, the habitats of marine animals in the coastal zone can be divided into coastal waters and waters surrounding islands and reefs in the open sea. Typical example The first option is shown in the accompanying illustration.

We present a list of the most common freshwater (river) fish. Names with photos and descriptions for each river fish: its appearance, taste qualities fish, habitats, fishing methods, time and method of spawning.

Pike perch, like perch, prefers only clean water, saturated with oxygen and conducive to the normal functioning of the fish. This is pure fish without any ingredients. The growth of pike perch can be up to 35 cm. Its maximum weight can reach up to 20 kg. Pike perch meat is light, without excess fat both very tasty and pleasant. It contains quite a lot of minerals, such as phosphorus, chlorine, chlorine, sulfur, potassium, fluorine, cobalt, iodine, and also a lot of vitamin P. Judging by the composition, pike perch meat is very healthy.

Bersch, like pike perch, is considered a relative of perch. It can grow up to 45 cm in length, weighing 1.4 kg. It is found in rivers that flow into the Black and Caspian Seas. Its diet includes small fish, like a gudgeon. The meat is almost the same as that of pike perch, although a little softer.

Perch prefers reservoirs with clean water. These can be rivers, ponds, lakes, reservoirs, etc. Perch is the most common predator, but you will never find it where the water is turbid and dirty. To catch perch, fairly thin gear is used. Catching it is very interesting and entertaining.

The ruff has a peculiar appearance with the presence of very spiny fins, which protects it from predators. The ruff also loves clean water, but depending on its habitat it can change its color. It grows no more than 18 cm in length and gains weight up to 400 grams. Its length and weight directly depend on the food supply in the pond. Its habitat extends to almost all European countries. It is found in rivers, lakes, ponds and even seas. Spawning takes place over 2 days or more. The ruff always prefers to be at depth, as it does not like sunlight.

This fish is from the perch family, but few people know it, since it is not found in this area. It is distinguished by an elongated fusiform body and the presence of a head with a protruding snout. The fish is not large, no more than one foot long. It is found mainly in the Danube River and its adjacent tributaries. Its diet includes various worms, mollusks and small fish. The chop fish spawns in April with bright yellow eggs.

This is a freshwater fish that is found in almost all bodies of water. globe, but only in those that have clean, oxygenated water. When the oxygen concentration in the water decreases, the pike dies. Pike grows up to one and a half meters in length, weighing 3.5 kg. The body and head of the pike are characterized by an elongated shape. It’s not for nothing that it’s called an underwater torpedo. Pike spawning occurs when the water warms up from 3 to 6 degrees. It is a predatory fish and feeds on other species of fish such as roach, etc. Pike meat is considered dietary because it contains very little fat. In addition, pike meat contains a lot of protein, which is easily absorbed by the human body. Pike can live up to 25 years. Its meat can be stewed, fried, boiled, baked, stuffed, etc.

This fish lives in ponds, lakes, rivers, and reservoirs. Its color is largely determined by the composition of the water that is available in a given reservoir. In appearance it is very similar to the rudd. The roach's diet includes various algae, larvae of various insects, as well as fish fry.

With the arrival of winter, the roach goes to wintering pits. It spawns later than pike, around the end of spring. Before spawning begins, it becomes covered with large pimples. The caviar of this fish is quite small, transparent, with a green tint.

Bream is an inconspicuous fish, but its meat is characterized by excellent taste. It can be found where there is calm water or a weak current. Bream lives no more than 20 years, but grows very slowly. For example, a 10-year-old specimen can gain weight no more than 3 or 4 kilograms.

Bream has a dark silvery tint. Average duration life is from 7 to 8 years. During this period, it grows up to 41 cm in length and has an average weight of about 800 g. Bream spawns in the spring.

This is a sedentary fish species with a bluish-gray color. The silver bream lives for about 15 years and grows to a length of up to 35 cm, with a weight of 1.2 kg. Silver bream, like bream, grows quite slowly. They prefer bodies of water with standing water or slow currents. In spring and autumn, the silver bream gathers in numerous flocks (dense flocks), hence its name. The silver bream feeds on small insects and their larvae, as well as mollusks. Spawning occurs at the end of spring or beginning of summer, when the water temperature rises to +15ºС-+17ºС. The spawning period lasts from 1 to 1.5 months. Silver bream meat is considered not tasty, especially since it contains a lot of bones.

This fish has a dark yellow-golden hue. It can live up to 30 years, but already at 7-8 years its growth stops. During this time, the carp manages to grow up to 1 meter in length and gain a weight of 3 kg. Carp is considered freshwater fish, but it is also found in the Caspian Sea. Its diet includes young shoots of reeds, as well as eggs of spawned fish. With the arrival of autumn, its diet expands and begins to include various insects and invertebrates.

This fish belongs to the carp family and can live for about a hundred years. May eat undercooked potatoes, bread crumbs or cake. Distinctive feature Cyprinidae is the presence of a mustache. Carp is considered a voracious and insatiable fish. Carp lives in rivers, ponds, lakes, and reservoirs where there is a muddy bottom. Carp likes to pass pliable silt through its mouth, in search of various bugs and worms.

Carp spawns only when the water begins to warm up to a temperature of +18ºС-+20ºС. Can gain weight up to 9 kg. In China it is a food fish, and in Japan it is a decorative food.

Very strong fish. Many experienced fishermen fish for it, using powerful and reliable gear.

Crucian carp is the most common fish. It is found in almost all bodies of water, regardless of the quality of the water and the concentration of oxygen in it. Crucian carp is able to live in reservoirs where other fish will immediately die. It belongs to the carp family, and in appearance it is similar to carp, but does not have a mustache. In winter, if there is very little oxygen in the water, crucian carp hibernate and remain in this state until spring. Crucian carp spawns at a temperature of about 14 degrees.

Tench prefers ponds with dense vegetation and covered with thick duckweed. Tench can be caught well from August, before the onset of real cold weather. Tench meat has excellent taste characteristics. It’s not for nothing that tench is called the king’s fish. In addition to the fact that tench can be fried, baked, stewed, it makes an incredible fish soup.

The chub is considered a freshwater fish and is found exclusively in rivers with fast currents. It is a representative of the carp family. It grows up to 80 cm in length and can weigh up to 8 kg. It is considered a semi-fat fish, since its diet consists of fish fry, various insects, and small frogs. It prefers to be under trees and plants hanging over the water, since various living creatures very often fall into the water from them. It spawns at temperatures from +12ºС to +17ºС.

Its habitat includes almost all rivers and reservoirs European countries. Prefers to stay at depth, if available slow flow. In winter it is as active as in summer, as it does not hibernate. It is considered a fairly hardy fish. It can have a length from 35 to 63 cm, with a weight from 2 to 2.8 kg.

Can live up to 20 years. The diet consists of both plant and animal foods. Ide spawning occurs in spring period, at water temperatures from 2 to 13 degrees.

It is also a representative of the family of carp fish species and has a dark bluish-gray color. It grows up to 120 cm in length and can reach a weight of 12 kg. Found in the Black and Caspian Seas. Selects areas with fast currents and avoids stagnant water.

There are saberfish with silver, grayish and yellow colors. It can gain weight up to 2 kg, with a length of up to 60 cm. It can live for about 9 years.

Chekhon grows very quickly and gains weight. Found in rivers, lakes, reservoirs and seas such as the Baltic Sea. At a young age it feeds on zoo- and phytoplankton, and with the arrival of autumn it switches to feeding on insects.

It is easy to confuse rudd and roach, but rudd has a more attractive appearance. Over the course of 19 years of life, it is able to gain weight of 2.4 kg, with a length of 51 cm. It is found, for the most part, in rivers that flow into the Caspian, Azov, Black and Aral seas.

The basis of the rudd's diet is food of plant and animal origin, but most of all it likes to eat caviar of mollusks. Enough healthy fish with a set of minerals such as phosphorus, chromium, as well as vitamin P, proteins and fats.

The podust has a long body and chooses areas with fast currents. It grows up to 40 cm in length and weighs up to 1.6 kg. The podust lives for about 10 years. It feeds from the bottom of the reservoir, collecting microscopic algae. This fish is distributed throughout Europe. Spawns at a water temperature of 6-8 degrees.

Bleak is a ubiquitous fish, known to almost any person who has fished with a fishing rod in a pond at least once. Bleak belongs to the family of carp fish species. It can grow to small sizes in length (12-15 cm) with a weight of about 100 grams. It is found in rivers flowing into the Black, Baltic and Azov Seas, as well as in large bodies of water with clean, non-stagnant water.

This is a fish, the same as bleak, but slightly smaller in size and weight. With a length of 10 cm, it can weigh only 2 grams. Able to live up to 6 years. It feeds on algae and zooplankton, but grows very slowly.

It also belongs to the family of carp fish species, and it has a spindle-shaped body shape. It grows in length up to 15-22 cm. It is carried out in reservoirs where there is a current and there is clean water. The gudgeon feeds on insect larvae and small invertebrates. It spawns in the spring, like most fish.

This type of fish also belongs to the carp family. It feeds practically on food of plant origin. It can grow up to 1 m 20 cm in length and weigh up to 32 kg. It has high growth rates. Grass carp is distributed throughout the world.

The diet of silver carp consists of microscopic particles of plant origin. It is a large representative of the carp family. This is a heat-loving fish. The silver carp has teeth that are capable of grinding vegetation. It is easy to acclimatize. Silver carp are grown artificially.

Because it grows quickly, it is of interest to industrial breeding. Can dial for a short time up to 8 kg weight. It is mostly distributed in Central Asia and China. Spawns in the spring, loves water areas where there is an intense current.

This is very major representative freshwater reservoirs, capable of growing up to 3 meters in length and weighing up to 400 kg. The catfish is brown in color but has no scales. Inhabits almost all reservoirs of Europe and Russia, where appropriate conditions exist: clean water, the presence of aquatic vegetation and suitable depth.

This is a small representative of the catfish family that prefers small reservoirs (canals) with warm water. In our time, it was brought from America, where there is quite a lot of it and most fishermen fish for it.

Its spawning occurs in conditions when the water temperature reaches +28ºС. Therefore, it can only be found in the southern regions.

This is a fish from the family of river eels and prefers freshwater bodies of water. This is a predator, similar in appearance to a snake, which is found in the Baltic, Black, Azov and Barents Seas. Prefers to be in areas with a clay bottom. Its diet consists of small animals, crayfish, worms, larvae, snails, etc. Capable of growing up to 47 cm in length and gaining weight up to 8 kg.

This is a heat-loving fish that is found in reservoirs located in large climatic zones. Its appearance resembles that of a snake. A very strong fish that is not so easy to catch.

It is a representative of the codfish and is similar in appearance to a catfish, but it does not grow to the size of a catfish. This is a cold-loving fish that leads an active lifestyle in winter time. Its spawning also occurs on winter months. It hunts mainly at night, while leading a bottom-dwelling lifestyle. Burbot is an industrial fish species.

This is a small fish with long body, covered with very small scales. It can easily be confused with an eel or a snake if you have never seen one in your life. It grows up to 30 cm in length, or even more if growth conditions are favorable. It is found in small rivers or ponds with a muddy bottom. It prefers to be closer to the bottom, and can be seen on the surface during rain or thunderstorms.

The loach belongs to the family salmon species fish Due to the fact that the fish does not have scales, it got its name. Grows to small sizes. Its meat does not decrease in volume under the influence of low temperatures. Characterized by the presence of fatty acids, such as omega-3, that can resist inflammatory processes.

Lives in rivers and feeds various types fish Distributed in rivers of Ukraine. Prefers non-deep water areas. It can grow up to 25 cm in length. It reproduces by caviar at water temperatures within +8ºС. After spawning, it can live no more than 2 years.

The lifespan of this fish is considered to be about 27 years. It grows in length up to 1 m 25 cm, gaining weight up to 16 kg. It is distinguished by its dark gray-brown color. In winter, it practically does not feed and goes into the depths. It has valuable commercial value.

This fish lives only in the Danube basin and is not common anywhere else. Belongs to the salmon family of fish species and is unique representative fish fauna of Ukraine. Danube salmon is listed in the Red Book of Ukraine and fishing for it is prohibited. It can live up to 20 years and feeds mainly on small fish.

It also belongs to the salmon family and prefers rivers with rapid currents and cold water. It grows in length from 25 to 55 cm, while gaining weight from 0.2 to 2 kg. The trout diet includes small crustaceans and insect larvae.

It is a representative of the Eudoshidae family, reaches a size of about 10 cm, while gaining a weight of 300 grams. It is found in the basins of the Danube and Dniester rivers. At the first danger, it buries itself in the mud. Spawning occurs in March or April. Likes to feed on fry and small invertebrates.

This fish is caught on an industrial scale in Edver and the Urals. Spawns at temperatures no higher than +10ºС. This is a predatory fish species that loves fast-flowing rivers.

This is a freshwater species of fish that belongs to the carp family. It grows up to 60 cm in length and gains up to 5 kg of weight. The fish is dark in color and is common in the Caspian, Black and Azov seas.

River fish without bones

Virtually no bones:

• In maritime language.
• In fish of the sturgeon family, belonging to the order Chordata.

Despite the fact that water has a certain density, the body of the fish is ideally suited for movement in such conditions. And this applies not only to river fish, but also to sea fish.

Typically, its body has an elongated, torpedo-like body shape. In extreme cases, its body has a spindle-shaped shape, which facilitates unhindered movement in the water. Such fish include salmon, podust, chub, asp, sabrefish, herring, etc. In still water, most fish have a flat body, flattened on both sides. Such fish include crucian carp, bream, rudd, roach, etc.

Among the many species river fish available as peaceful fish, and real predators. They are distinguished by the presence of sharp teeth and a wide mouth, which allows them to swallow fish and other living creatures without much difficulty. Similar fish include pike, burbot, catfish, pike perch, perch and others. A predator such as a pike during an attack is capable of developing a huge initial speed. In other words, it literally swallows its prey instantly. Predators such as perch always hunt in schools. Pike perch leads a bottom-dwelling lifestyle and begins hunting only at night. This indicates his uniqueness, or rather his unique vision. He is able to see his prey in complete darkness.

But there are also small predators that are no different large size graze. Although, such a predator as the asp does not have a huge mouth, such as a catfish, for example, and it feeds only on young fish.

Many fish, depending on their habitat conditions, can have different shades. In addition, different reservoirs may have different food supplies, which can significantly affect the size of the fish.