Silver crucian carp: description, habitat, reproduction

Carp family

Crucian carp belong to the most numerous class - ray-finned fish. They belong to the genus of crucian carp from the carp family. Their “brothers” are distributed mainly in the Northern Hemisphere, although they are also found in the Southern Hemisphere. These fish are definitely not found on the continents of South America and Australia.

Many representatives of cyprinids are commercial fish. They are caught in natural reservoirs, bred in artificial ponds, and some are kept in aquariums.

In addition to carp, crucian carp, bream, roach, roach, tench, there are also more exotic species among them. For example, on the islands of Kalimantan and Sumatra there is a small Sumatran barb, colored with vertical black stripes. The Thai labeo has a gray body and bright orange fins, while the green puntius has an olive color with black spots.

They also include a cute fish called “lady's stocking”, or zebrafish. It lives in Asia in the rivers of India, Pakistan, Nepal, and Bangladesh. Her body is elongated and painted with horizontal stripes of silver and black.

Population and species status

Photo: Karas

Golden crucian carp have approximately the same sex ratio. In its silver relative, the population of females is many times more dominant than the male population. There is evidence that the number of males among silver crucian carp is only about ten percent. Not so long ago, golden crucian carp was the dominant species in many reservoirs, but now the situation has changed, and in various places it has been replaced by its silvery counterpart after being artificially relocated. More and more often, hybrids formed by crossing these two species began to appear.

Despite the fact that crucian carp fishing is quite active, its population does not suffer from this; it still remains a widespread fish species. Ichthyologists have evidence that over the past 50 years there has been stability in the number of crucian carp. There are no jumps in the direction of a sharp increase or decrease in the population. And the number of silver crucian carp is increasing everywhere. The status of its species states that this fish is an object of sport, local and amateur fishing.

In the end, it remains to add that although the situation with the crucian carp population is favorable, people should not resort to poaching, catching en masse this good-natured and peaceful inhabitant of quiet reservoirs. Crucian carp will not be able to resist incessant poaching. Sitting on the shore for fun with a fishing rod is one thing, but widespread placement of nets is a completely different story, which smacks of trouble and negativity.

Description of silver crucian carp

The genus of crucian carp includes only a few species: common, or golden, silver, Japanese and goldfish. All of them are freshwater, but differ in habitat and external characteristics.

Silver crucian carp inhabit rivers, streams and lakes. It lives in Western and Eastern Europe, Italy and Portugal, Siberia, India and North America. It was brought to all these regions in the second half of the 20th century from the Amur River, its original homeland. Currently, it is a serious competitor to golden crucian carp, and in some reservoirs it has contributed to its extinction.

The fish has a tall body with a rounded and thick back. His body is slightly flattened laterally. The dorsal fin is long and wide. One of its first rays is transformed into a sharp spine, just like the anal fin.

It is covered with smooth and wide scales, semicircular in shape. The color is silvery-greenish or grayish. In some cases, it has pink and orange shades. Silver crucian carp is a medium-sized fish, it grows up to 40 centimeters in length and can weigh up to two kilograms.

Range, habitats

Silver crucian carp are found in the basins of rivers such as the Danube and Dnieper, Prut and Volga, as well as in the lower reaches of the Amu Darya and Syr Darya. Such representatives of freshwater ray-finned fish have become quite widespread in the waters of floodplain lakes of Siberian rivers and in the Amur basin, in the river waters of Primorye, as well as in reservoirs in Korea and China. The habitat of the natural distribution of silver crucian carp is very difficult to restore, but such fish are well adapted to currents, all kinds of river and lake fish, and therefore are perfectly adjacent to golden crucian carp.

In recent years, silver crucian carp have been quite actively spreading even in new habitats for this species, and are also able to displace golden crucian carp, which is due to the excellent species endurance and ability to survive in waters with extremely low oxygen levels. During dry periods, when the reservoir naturally dries out, crucian carp burrow into the muddy layer, going seventy centimeters deep, where they can easily “wait out” the most unfavorable time.

It is also surprising that representatives of this species can maintain full viability during wintering in water bodies that freeze strongly to the bottom. Caught crucian carp are able to live for three days in ventilated containers or baskets filled with well-moistened grass. However, the fairly rapid death of such fish is caused by oversaturation of the water with hydrogen sulfide, as well as other highly toxic substances for living beings.

The rate of colonization of new water bodies by silver crucian carp is simply incredible, and according to such indicators, this species may well compete with the unpretentious verkhovna carp. Some fish farmers have expressed the idea that silver crucian carp in the reservoirs of our country have quite successfully supplanted many of their closest relatives. However, silver crucian carp prefer well-warmed reservoirs with standing water and a soft bottom. In rivers, such fish are rare species and try to stay in places with a slow current. In the waters of flowing lakes and ponds, crucian carp of this species are also quite rare.

Differences from other fish

Silver crucian carp are sometimes easily confused with other representatives of its order. But this fish has characteristic features. The easiest way to distinguish it is from the goldfish, which is larger in size and has a rich copper and sometimes reddish color.

In the silver species, the head is more elongated and pointed, the fins are slightly longer, and the body forms a smooth arc. The goldfish has a wider body, and its back in the area of the fin is noticeably curved into a hump (see picture below). In addition, the latter has smaller scales, and there are more stamens in the gills.

You can try to confuse our crucian carp with carp, but even here there are several clues. Firstly, the carp's body is more elongated. Secondly, it is convex with a hump from the head to the dorsal fin (seen in the picture below). Its scales are larger, have a dark border around the edges and black spots at the base.

The head and eyes of carp are larger than those of crucian carp. The mouth is also larger and lowered, and the lips are thick. The carp is also distinguished by two short antennae, which crucian carp do not have. Dorsal fin with a small notch. In crucian carp it is even, decreasing towards the head.

Why are carp and crucian carp often confused?

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Often, even experienced fishermen, having caught a small carp weighing up to 1 kg, carelessly send it to the fish tank, mistaking it for an ordinary crucian carp.

There are several reasons for this:

External similarity (body shape, color, scale size, etc.).
General habitat (still water, reservoirs with muddy bottoms, snags, edges, depressions, etc.).
Similar bites (puts the float down or moves it to the side).
The same baits that these fish readily catch (bloodworms, worms, maggots, dough, corn, etc.).

Of course, it is impossible to confuse crucian carp with large individuals or mirror carp. Therefore, what is described above is more typical for small scaly carp and silver carp, which at first glance have several visual similarities.

Lifestyle of crucian carp

This is one of the most unpretentious fish. It adapts perfectly to many conditions and can live in bodies of water that other fish would not dare to approach. For example, in lakes thickly covered with mud.

Silver crucian carp loves reservoirs with a muddy bottom and mud, in which they look for worms and the remains of small animals. It can inhabit large lakes and rivers; golden crucian carp, in contrast, is less common in flowing water bodies.

By and large, crucian carp are omnivores. In addition to particles of dead animals, they feed on zoo- and phytoplankton, insect larvae, and small crustaceans. It itself serves as food for large and agile predators such as perch, pike or ruff.

Crucian carp tolerate unfavorable conditions better than other fish. If this happens, they can bury themselves in the “nyasha” and wait it out. Sometimes still living fish are found under a thick layer of silt, in places where the reservoir has long dried up.

In spring and summer, fish tend to move to areas with warm temperatures, often approaching shallow waters. They search for food especially actively in August, after spawning. During this period, they need to recuperate and gain energy before winter.

Before the onset of cold weather and before the final freezing of reservoirs, crucian carp go into wintering pits. These are areas with the least cold temperature in the reservoir, as well as a calm current. In winter they practically do not feed and begin to be awake only in spring.

Lifestyle

Usually crucian carp stays near the bottom or in thickets of underwater vegetation. It can rise to the upper layers of water, for example, during a period of mass emergence of insects. Forms schools; large fish can stay alone. It is unpretentious to the quality of water; in case of unfavorable conditions (drying out or freezing of the reservoir, low oxygen content in the water), it buries itself in the silt and hibernates. It can remain in this state for quite a long time.

Daily and seasonal activity

In different reservoirs, the daily activity of crucian carp is not the same. It is usually active in the morning and evening hours, but in some ponds and lakes it can only feed at night. This especially applies to those reservoirs where crucian carp have to share habitats with predatory fish.

Among other things, daily activity is influenced by weather conditions. For example, in the summer heat, crucian carp can feed only in the morning, when the water temperature in the reservoir is minimal, and in cloudy and cool weather - throughout the day.

The seasonal activity of crucian carp depends on the conditions in the reservoir. In flowing ponds and reservoirs with good oxygen conditions, crucian carp can be active all year round. In stagnant lakes, where oxygen starvation is likely in winter, crucian carp will most likely go into hibernation. It can also hibernate in the middle of summer - if the body of water in which it lives warms up well. A strong bloom of water caused by phytoplankton can also force crucian carp to reduce activity. On rivers, crucian carp are usually active all year round.

Migrations

Silver crucian carp leads a predominantly sedentary lifestyle, but during spawning it is quite capable of leaving lakes for tributaries and ascending rivers.

Natural enemies

Fish such as perch, pike perch, pike and burbot feed on small specimens of crucian carp. Among other animals, crucian carp is attacked by snakes - the common snake and the viper. When crucian carp feeds in shallow water or closer to the surface of the water, it is hunted by fish-eating birds - gulls, terns, and grebes.

Large crucian carp can be caught by heron and osprey, as well as predatory mammals - mink and otter.

Nutrition

Personality: omnivore.
Objects: aquatic and semi-aquatic invertebrates, insects and their larvae, algae, higher plants, detritus. Unlike golden crucian carp, plant foods and planktonic crustaceans are of greater importance in the diet of silver crucian carp.
Seasonal preferences: in the cold season it prefers animal food, the rest of the time it is omnivorous.
Prey sites: in ponds and lakes, these are muddy areas of the bottom, or areas near the banks with thickets of semi-aquatic vegetation, where crucian carp scrape settled detritus and invertebrates from the stems. When a fish feeds in such places, it usually makes its presence known with characteristic smacking sounds. In rivers, crucian carp stay in stretches with moderate or slow currents. Thickets of underwater plants, as well as the mouths of tributaries and bushes hanging low over the water - all this also attracts crucian carp.

Spawning

Age of sexual maturity: 2-4 years.
Required water temperature: 13-15 °C.
Spawning grounds: areas of the bottom overgrown with plants.
Nature of spawning: usually portioned, but in some steppe reservoirs the eggs can be spawned in one go.
Features: female goldfish are capable of gynogenesis - reproduction without the participation of males of their species. The essence of this method is that silver crucian caviar can be fertilized by the milk of other carp fish (carp, carp, tench, golden carp). In this case, full fertilization does not occur - the eggs are only stimulated to develop, and all the larvae that hatch from it are genetic copies of the female that laid the eggs. Because of this, in some reservoirs the population of crucian carp may consist entirely of females.
Period (for the Middle Urals): second half of May - beginning of June.

Reproduction

Spawning of silver crucian carp begins in May or early June. The main condition for the opening of the mating season is temperature. When the water exceeds 13-15 degrees, the fish begin to look for a mate and perform “wedding” rituals with might and main.

During this period, they completely refuse food. Eggs are laid in lush thickets of reeds, sedges and reeds, clinging to plant stems. After which the males fertilize her.

When only female individuals live in a reservoir, related species interact with the eggs. Their sperm speeds up development, but does not fertilize the eggs properly. In this case, exclusively female individuals are born, natural clones of their mother. This phenomenon is called gynogenesis.

The silverfish fry initially feeds on plankton, eventually moving on to larger foods. However, not everyone survives to adulthood. Their eggs are also eaten by frogs, newts, aquatic insects, birds and other fish.

Fishing for crucian carp

To catch goldfish, you need to know their schedule. In the spring, it is important for the fisherman to “watch” for the time when the fish are about to begin their mating season. Just before spawning and in the first days of searching for a pair, crucian carp are very active and eat literally everything they see.

Immediately after droppings, the fish also begins to eat. For a successful catch, you should choose a time with stable and calm weather that lasts for several days.

In summer, crucian carp have an abundance of food, so it becomes more difficult to “lure” them onto a hook. It is simply impossible to predict what the bite will be like. They are best caught in summer in ponds and lakes, where there are practically no other fish. The most favorable hours for fishing are early morning or before dawn.

In August, the fish are again actively looking for food, but in the fall its appetite decreases. Fish swim deeper into water bodies and switch to animal food. Here you have a better chance of catching crucian carp using maggots, worms and other protein baits, casting your fishing rod further away.

Breeding

Thanks to their excellent ability to adapt to different conditions, silver crucian carp are easy to breed in your own pond. It is advisable that the reservoir is not too shallow, about 2 meters deep.

For food, fish can be given special food, steamed cereals, as well as insects, maggots, worms, in general, everything that is used to catch them. Sometimes duckweed, an aquatic grass, is thrown into reservoirs. It contains a large number of useful elements, but it grows very quickly and needs to be removed periodically.

They feed crucian carp up to two times a day, and in cold weather they stop feeding altogether. You can't give too much food. What is not eaten will begin to rot and degrade the water quality in the pond.

Commercial value

Many representatives of cyprinids, including silver crucian carp, are quite valuable commercial fish . Representatives of this species were introduced into waters in North America, ponds in Thailand, Western Europe and India.

Relatively recently, silver crucian carp has taken root well, thanks to which it has become a popular commercial fish in our country, in the lakes of Kamchatka. In recent years, goldfish are often raised in pond farms or bred by farmers. Among other things, the subspecies of silver crucian carp became the basis for the breeding of aquarium goldfish and other ornamental breeds in China.

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From silver to gold

The goldfish is the ancestor of the goldfish. It was from this that the Chinese developed this decorative beauty back in the Middle Ages. From there, the fashion for it spread to Asia, and only then captured Europe.

It includes many breeds that are distinguished by a variety of colors. The common goldfish is entirely orange. It can grow up to 30 centimeters in length and is more similar to the silver crucian than its other counterparts.

There are also fish with white-orange, dark brown, and black colors. Their fins and tails are often elongated and resemble butterfly wings. There are species with huge eyes, swollen bodies and other features. They are bred in aquariums and also used in laboratories for various studies.

Learning to distinguish carp from crucian carp by appearance

Regardless of the gear and type of fishing, it is almost impossible to catch crucian carp in Russia that weighs more than 2 kg. Therefore, if you hook a fish that is clearly larger than a couple of kilograms, then it is 99% carp. If it has small antennae, and the scales are smaller and softer to the touch, then you can cast aside any doubts about your catch.

Only small scaly carp weighing up to 800-900 grams can be easily confused with crucian carp. However, it also has significant differences, “suggesting” that the fisherman is looking at a more noble representative of the cyprinids.

First of all, look at the head. In carp it is more prominent and massive. The lips are fleshy and yellowish, quite mobile. The mouth is much larger than that of crucian carp of the same size. All carp have a small hump on their nose. At the same time, the shape of the head is more angular and elongated than that of crucian carp.

As for the body, even in small carp it is thicker and longer. If an angler takes a carp in his hands, he can, without much effort, slightly bend its body. This technique will not work with crucian carp. Its body is denser due to its high back.

Next, pay attention to the dorsal fin. In carp it is longer and has a protruding front ray followed by a decent notch

The dorsal fin of crucian carp is smooth and even slightly rounded at the top. The tail and lateral fins can also help distinguish between the two lake “brethren”. In crucian carp they are most often black or dull gray in color, slightly transparent in the light. Carp are characterized by dark purple or even orange fins, as well as a tail with a reddish tint.

Many crucian carp also have slight roughness on the gill arches, which are not at all characteristic of carp. They can be easily felt with your finger. Some experienced fishermen note that crucian carp and carp can be distinguished by eye color. If in the closest relative of the carp they are yellow-golden (sometimes copper) with an enlarged black pupil, then in the crucian carp they are cloudy and slightly convex. The color of the carp's body is more saturated: the back is dark with a greenish tint, the sides and lower part are close to yellow.

Carp differs from crucian carp in the number of pharyngeal teeth. In the “noble” representative of the carp family they are more massive and are located in two rows. He has ten of them in total. Five pieces on each side. Crucian carp have single-row pharyngeal teeth, four on the right and left.

Thus, there are many visual signs by which it will not be difficult to determine which of the two fish described above you caught or simply want to buy in the store.