CATDOLL : CATDOLL: Can freshwater fish survive in the sea? Why can't freshwater fish live in the sea?

1. Can freshwater fish survive in the sea? Why can't freshwater fish live in the sea?

Freshwater fish cannot survive in the sea. The osmotic pressure of seawater and freshwater is different, so the water needs of fish living in the two waters are also different. The osmotic pressure of freshwater fish is higher than that of water, so water will continue to enter from the body surface, and the fish needs to discharge excess water from the body. When entering seawater, because the osmotic pressure of seawater is higher, the water in the fish's body will automatically seep out, causing it to die of dehydration. 1. Can it survive? Freshwater fish cannot survive in the sea. Freshwater fish live in freshwater, and the osmotic pressure of water is lower than the osmotic pressure in the fish's body, so water will gradually seep in from its body surface, and the fish needs to keep draining water to maintain balance. Marine fish live in saltwater, and the osmotic pressure of saltwater is higher than the osmotic pressure of the fish's body, so water will gradually drain away, and the fish needs to drink water constantly. If a freshwater fish is placed in seawater, it will die from dehydration due to excessive salinity.

2. Common Freshwater Fish 1. Luohan Fish: Luohan Fish is an ornamental fish specially bred by crossbreeding. It is named because its head resembles Luohan. This fish has a very wide body shape, a longer body and a taller body. Its forehead is very full, and it is not prone to disease and is very easy to raise. It has a wide diet and can be fed with natural feed or artificial feed.

2. Silver Arowana: The scientific name of Silver Arowana is Osteoglossus bicolor. Its body length is generally between 50-70 cm, and the maximum can reach about 120 cm. This fish lives in tropical areas and prefers quietness. It usually feeds on fish, shrimp and shellfish. It is good at jumping and can catch prey on branches above the water.

3. Atlas fish: Atlas fish is native to South America. It has a cute appearance and delicious meat. It usually lives in the middle and lower layers of water bodies. It has low requirements for water quality and can grow in weakly acidic and weakly alkaline waters. As a carnivorous fish, it cannot be raised together with small tropical fish, otherwise it will eat them.

2. Which common freshwater fish have the least bones?

Eel, mud eel, catfish.

3. What are the freshwater fish that live in the upper layer of the water?

Common freshwater fish living in the upper layer of the water surface include grass carp, black carp, silver carp, bighead carp, black carp, and other fish.

If you are doing aquaculture, you must consider the economic value. The top layer that can be mixed with eels and has economic value is none other than the Cockroach. It can accept granular feed and mixed wet feed, and can be fed with eel bait. It grows faster and is easy to survive.

4. What are the living habits of common freshwater fish?

Black carp is also called black carp, black carp, black carp, black carp. It lives in the middle and lower layers of water bodies and generally does not swim to the surface. Its diet is relatively simple, with snails and clams as its main food. Young fish raised in ponds like to eat grain feed. After reaching a body length of 15 cm, the crushing function of the pharyngeal teeth is enhanced, and its diet changes. The mortality rate is high before the age of 2, and its diet is mixed, with grain bait as its main food. After the age of 2, especially when its body weight reaches 1 kg, its diet turns to soft aquatic animals, and it can grind hard shells and spit out the shells and eat the meat. In natural waters, it often gathers at the junction of deep and shallow parts of rivers and lakes. Except for the weak appetite in winter, it eats vigorously in spring, summer and autumn, and can bite the hook and swallow the bait when the air pressure is low and most bottom-dwelling fish are generally anorexic.

Fishing for black carp usually uses traditional fishing methods. The fishing tackle is a hard-tuned long pole with a thick line and a large hook. The pole length is generally not less than 6.3 meters, and the line should be No. 4 or 0.55 mm in diameter with a tension of more than 7 kg. Although the hook model is not very particular, the thickness of the hook and the width of the hook gate are very important. When the black carp bites the hook, the reaction of the float is stable and stagnant, and the fluctuation of the float is not large, and it is relatively stable. But the second signal that follows is to slowly drag the float into the water, and you will not see the float float again. The black carp has a large body weight, and when you lift the rod and feel that there is a fish on the hook, it generally does not suddenly rush sideways. The common situation is that it swims out steadily and leisurely, and its strength is just like an old cow plowing the land, forming a tug-of-war between man and fish using the rod and line. At this time, the only way is to change the position, or follow the fish along the shore, or change the pulling direction, and use the arm strength to make the rod bend sideways and then deal with it. Otherwise, the fish will escape. In winter or when the air pressure is low, the bite of black carp is often manifested by the float sinking slightly, and then there is no second signal. When lifting the rod, you can't feel the shaking of the hook after it hits the fish's lip, as if the hook accidentally hits the underwater hidden pile, forming a stalemate. After a few minutes, you can see the fishing line slowly moving outward. Generally speaking, at this time, the hook has firmly pierced the upper lip of the fish. As long as you are not impatient when pulling, follow the direction of the fish's swimming to keep the bend of the rod in a parabola state, the fish will not escape.

When fishing for black carp in natural waters, you can choose to cast your hook on the outer edge of a curved bank with a gentle current. In aquaculture waters such as ponds and small lakes, it is better to choose a deep one.

Grass carp is also called silver carp, grass carp, mixed fish, and grass carp. Grass carp is a semi-migratory fish that lives in the middle and lower layers of water bodies and can eat grass leaves and vegetable stems on the surface of the water. It has a lively temperament, swims quickly, and often forages in groups. In winter, its appetite decreases sharply, and it mostly hibernates in deep water areas. Grass carp is also a typical herbivorous fish. Fry, juvenile and young fish mainly feed on animal bait, and their feeding habits change with the development of pharyngeal teeth and the lengthening of the intestine. In pond breeding, feeding habits can shift to commercial feeds.

When fishing for grass carp, in addition to the traditional single-hook bottom fishing, the main methods used in summer and early autumn are multi-hook hanging fishing and floating fishing.

When fishing with multiple hooks, you can tilt them upward from the bottom of the water, so that the hooks are suspended in the middle and lower layers of the water body in a ladder-like shape. This is often used with a casting rod. When using a hand pole, the multiple hooks are in a vertical state, and generally there are about 3 hooks. Dough is often used as bait for hanging fishing. Grass leaf juice or green vegetable leaf juice can be mixed with flour, kneaded repeatedly into a ball, and then rolled into a 1mm ball to hook the hook. There are also insects such as grasshoppers, oil gourds, and dragonflies as bait. Grass carp has a large mouth, and biting the hook often manifests as swallowing, so there is no need to hang a float. The timing of raising the pole can be directly grasped by the violent shaking of the pole tip and the large downward bend.

When floating fishing, hand poles are often used with floats with greater buoyancy, and floats are often used instead. In summer and early autumn, grass carp are used to swimming in the waves at the wind outlet. You can use grass leaves, vegetable leaves, tender reed cores, fresh green leaves, stems to directly hook the hook, and rely on the buoyancy of the float to make the hook hang on the surface of the water, with a depth of about 20 to 30 cm. In order to increase the target of the bait, you can constantly pull the fishing line or let the float drift on the water surface with the wind to attract the attention of the fish. Grass carp has strong struggling power, but lacks persistence. It is easy to subdue it as long as the pole, line and fish are not in a straight line.

Traditional hand-pole bottom fishing is still popular in the north, but the bait is more particular. Whether it is a special bagged grass carp bait or a bait prepared by the angler, the color and taste must be taken into consideration. The fake bait developed in recent years is a white foam plastic soaked in a mixture of koji wine and vegetable leaf juice, which has a very good effect.

Bighead carp is also called silver carp, black carp, Baotou fish, fat boy, and loose fish. Bighead carp lives in the middle and upper layers of water and has the habit of migrating between rivers and lakes. It usually lives in rivers and lakes with a certain flow rate. It has a gentle temperament, does not jump much, and moves slowly. The feeding habits of bighead carp are different from those of silver carp. It mainly feeds on zooplankton in the water, such as rotifers, cladocerans, copepods, and protozoa, and also eats a variety of phytoplankton.

Fishing for bighead carp is the same as fishing for silver carp, and the fishing gear is the same, but there is another special fishing method, which is to shake the rod and pull it hard, and use a single hook to pierce the fish body. Although bighead carp belongs to the upper layer of the water, it will dive to the bottom of the water to feed. In pond farming, the rapeseed cake powder that has been fermented for too long and has become smelly is very easy to cause bighead carp to gather. The density can be seen by shaking and shaking the float from side to side, and small bubbles as big as rapeseed grains will appear on the water surface. The so-called shaking the rod means that after the angler knows that the fish are gathering at the bottom of the water, he will hang an empty hook without bait on the bottom of the water, and rely on the shaking, shaking and deep floating of the float, and the coordinated movement of the wrist and arm to continuously pull it hard and pull it hard, so that the hook tip will pierce the fish body or hook the fins when it touches the fish body. When using this method, it is important to have a sharp hook tip, and at the same time, the neck of the commercially available fishing hook (that is, the part of the hook body from the hook tip to the hook bend) must be turned outward. The action of shaking the rod and pulling it violently should be sudden, and the angle should be changed from time to time. The double-pointed one-piece hooks and anchor hooks currently on sale are suitable for this fishing method and special fishing gear. This fishing method requires hard-tuned and super-hard-tuned rods, and the length of the rod is generally not more than 4 meters, so as to be suitable for use in shallow water near the shore.

There are many ways to fish for carp. Whether you use a casting rod, hand rod, pull rod or hand line, you can fish it effortlessly. The key lies in the size of the individual and the timing of baiting. For one-year-old fish or fish weighing less than 500 grams, earthworm bait is the most suitable. For fish over two years old, as the fish grow larger, their feeding habits begin to lean more towards grains, so dough, cooked potato pieces, etc. should be used as bait instead. When carp is foraging at the bottom, a nest of mung bean-sized bubbles (more than ten to twenty in number) will first appear on the water surface, interspersed with bubbles the size of soybeans and broad beans. If there are dead branches and leaves and old grass stems at the bottom of the water, you can see broken branches and stems constantly floating to the surface. In shallow waters with a depth of less than 50 cm, you can also see muddy yellow muddy water rolling in clumps. In the familiar water area, carp will develop a certain ability to identify bait and fishing line. At this time, although there are bubbles on the water surface and the line is rubbed and the float is shaken from time to time, the fish will not be caught. There are two ways to deal with this type of carp: one is to change the bait and adjust the hook, that is, change the big hook to a small hook, and the big bait to a small bait. The "small bait" here refers to both the size of the bait and the material of the bait. It is very effective to use rice grains and maggots to deal with carp living in the bottom of the water with rich humus layer. The second is to change the line. Although the nylon rubber wire commonly used to fish carp is mostly transparent and colorless, it is easy to be detected by sensitive fish because of its thick line diameter. You can use 0.8-1 strong fishing line or shadowless line instead. The living habits and fishing methods of crucian carp

Crucian carp is also called crucian carp, happy head, boy crucian carp, knife fish. It is a widely adaptable fish. It can live in deep water, shallow water, clear water, turbid water, flowing water, still water, large water bodies and small water bodies. It likes to live in shallow river bays and lake coastal waters with dense aquatic plants. It has strong vitality and can even grow and reproduce in low-oxygen, alkaline and unfavorable water bodies. Crucian carp is an omnivorous fish. Its diet is roughly the same as that of carp. The bait used for carp can also be used to catch crucian carp.

The feeding habits of crucian carp in different water bodies are different: crucian carp in rivers prefer food bait, crucian carp in lakes prefer fishy bait, and crucian carp in ponds eat both. Different species of crucian carp have different feeding habits: white crucian carp prefers plant bait and can bite the hook suspended from the bottom of the water; silver crucian carp likes food bait and mollusks such as earthworms and maggots, and bites the hook more in the lower water near the bottom; native crucian carp prefers rice bait and is not picky about earthworms, and more often feeds on the bottom. The commercially available bagged crucian carp bait uses potato flour as the aggregate, adds wheat flour and other ingredients, and adds certain natural spices. It has a broad spectrum and is suitable for all kinds of crucian carp, but it must be matched with the fishing group to achieve good results. When using traditional fishing methods, because the special bait is instantly soluble, a small amount of flour should be added to increase the viscosity to prevent it from dissolving prematurely. A very important point in fishing crucian carp is to choose the hook line. In order to increase the hooking rate and save time in hook removal, you can choose a barbless fishing hook. Because the fish is not big, a general hand rod can easily lift the fish out of the water, and a 3.6-5.4m medium-adjustment fiberglass hand rod can do it with ease. Fishing crucian carp with ordinary fishing hooks requires sharp hook tips. The crucian carp's bite action will appear in various forms such as swallowing and spitting, running with the hook in hand, or suddenly attacking with the climate changing; at the same time, it will also appear different due to the hardness of the bottom mud and the flatness of the terrain. The lip ring of the crucian carp is tender and thin. When lifting the rod, you must skillfully use the wrist strength. Excessive force can easily tear the fish lip.

The life habits and fishing methods of bream

Bream and bream are similar in appearance and have similar habits. People also tend to classify bream and bream as one and call them bream. Bream is also called round-head bream, Wuchang fish, flat fish, bream flower, grass bream, and long bream.

Bream and bream are both mid- and lower-layer fish. They like to live in rivers and lakes with aquatic plants. Their main food is higher aquatic plants and zooplankton. In ponds, bream and bream eat both various green fodders and grain baits. Their living habits are very similar to those of grass carp. They can live on the bottom and eat various food scraps, and they can also grab all kinds of sinking food in the middle layer of water. In summer and autumn, they can even peck at grass stems and leaves close to the surface of the water. Therefore, the method of fishing for grass carp can be used to fish for bream and bream.

Fishing for bream and bream generally does not require a particular fishing spot. They can be caught in any area of ​​a breeding pond. However, in rivers, you should choose the outer waters of slow flow or backflow; in lakes, you should look for open areas with free water and shallow bays where submerged plants grow. Whether in rivers, ponds, or lakes, there must be clusters of bream and bream in any water area with surface plants, and there are bites in the upper, middle, and lower water layers. Therefore, when choosing fishing gear, you should use a lighter sinker to allow the hook to slowly sink from the water surface to the bottom of the water. If there is an obstruction during the sinking process, it means that the hook has been bitten by the fish in the middle layer. At this time, the angler can shake the fishing rod violently and then gently lift the fish. Bream and bream are medium-sized fish. Their wide and laterally flattened bodies make it difficult for them to struggle for a long time in the water. However, if the hook tip cannot penetrate the thick lip ring of the fish in one go when the rod is lifted, it is easy for the fish to escape. Like crucian carp, bream and bream bite the hook mostly by lifting the float, that is, the part of the float that sinks into the water will slowly float to the surface. The timing of lifting the rod should be grasped at the moment when the float floats up but has not yet fully floated. If you use the floating fishing method, you can cut the green leaves into 2 cm wide strips and roll them into a stick-shaped hook, or you can hang earthworms and dough. If you use a casting rod to fish bream and bream, you can either equip the sucking group hook with bad food, or you can hang bait on each single hook of the group hook to form a "grape hook". When using a string hook, you should use a small casting rod with a softer and more elastic tip. This is because the bream and bream bite the hook with a small amplitude and are not easy to observe. Only a pocket rod with a thinner tip will have obvious shaking.

Fish habits and fishing methods

Fish is a general term, including redfin, redfin, Mongolian redfin, pointed redfin, Dashi redfin, etc. Fish are called whitefish, whitefin whitefish, and redfish in different places due to different species. Their sizes vary greatly. The largest redfin can grow to more than 10 kilograms. Mongolian redfin is only about 1 kilogram, while Dashi redfin is less than 500 grams. Fish mostly live in rivers, lakes, and reservoirs. They swim quickly and eat aggressively. They are typical ferocious carnivorous fish.

When fishing, you must constantly observe and patrol the activities of the fish school. When they hide underwater, you can see frightened shrimps jumping on the water surface. In open water areas, you can see the "bang" sound and water splashes left by them attacking small fish and shrimps from bottom to top. In the water grass, you can see them snatching shrimps under the leaves of aquatic plants, disturbing the leaves of the plants. The fishing method should be different according to the environment. Use floating fishing with a floating hook in large water surfaces, and use lifting fishing in places where water grass and aquatic plants are lush. Floating fishing often uses a casting rod, a large float, and fresh shrimp as bait. After throwing the float and hook dozens of meters downwind, let the float and bait hook go with the wind and waves. In order to induce scattered fish to gather, you can break bread into pieces and throw them out, or simply hang a small piece of bread on the hook as bait. The fish caught by this method are all red snappers, which are generally large in size, but it is limited to lakes. Lift fishing refers to fishing in lakes or rivers with lush surface plants. The angler hooks the shrimp with the shell on the bow and drops it into the gaps between the aquatic plants. The angler swings the hook up and down with his hands to make the hook move up and down to lure the fish foraging in the upper and middle layers to grab the food. There is no need to hang a float when lifting fishing. The fish bitten by the hook can be thrown into the cabin directly by hand. The fishing gear used is mostly hard-adjusted rods, but the rod tip must still maintain a certain degree of elasticity. The fishing line is generally only half to two-thirds of the length of the rod, and the most common hooks are long-handled 316-type and sleeve-type hooks.

Fishing can also use fake bait. This is an axe-shaped copper block. When using it, use the "copper plate" instead of bait, let the hook sink into the middle layer of the water, and then quickly pull the fishing rod. Using the resistance of the water, the copper plate rotates around the fishing line and the hook handle. The shiny reflection will make the fish mistake it for the reflection of the shrimp shell, and thus compete for food.

The life habits and fishing methods of catfish

Catfish is also a general term. It includes roundmouth catfish, reverse fish, fine-scaled oblique-jawed catfish and yellow-tailed catfish. Although reverse fish are common, anglers disdain them because they are too small. The most representative catfish are fine-scaled oblique-jawed catfish and yellow-tailed catfish. They are easily confused with Mongolian red among fish and are mistakenly classified as fish. In addition, because their fins, except for the dorsal fin, are orange-yellow to varying degrees, they are also called yellow long skin, yellow fork, yellow aunt and yellow tail. Catfish are bottom fish, and their main food is higher plant debris, bottom humus and aquatic insects. In winter, they gather in deep water to hibernate, and in spring, they disperse to forage.

Fishing for carp should be done in small and medium-sized lakes and reservoirs, especially small lakes connected to rivers, and places with lush aquatic plants at the mouth of rivers. Grain crumbs and rice grains can be used as bait. Carp bite the hook mostly by "lifting the float", and can even hold the sinking hook bait halfway. When they gather in groups to the fishing spot, the hook is often blocked repeatedly during the sinking process, as if it is supported by something and difficult to sink to the bottom of the water. The carp that catch the hook halfway is not large, about 100 to 150 grams. When the hook sinks to the bottom of the water, the carp bites the hook and can quickly float it up. The appetite of carp is the strongest in summer, and it does not decrease due to changes in air pressure. Earthworms are convenient bait for fishing carp, and half-hooks can be used. Several fish can be caught in a row with one hook, even if the earthworm body is broken and the hook tip is exposed. Fishing tackle can be medium-tempered and soft-tempered rods. A suitable fishing hook is an upturned hook with a tail handle and a sinker, because it is easy to put an earthworm on the upturned hook, and the sinker on the tail handle will reflect a faint light, making the fish mistake it for bait.

The foraging activity of silver carp is also related to the clarity of water, that is, it has a strong tendency to suddenly appear turbidity in clear water areas. In this regard, some dry soil blocks can be artificially sprinkled into the clear water area to cause turbidity in the local water area to attract fish.

Carp is a bottom-dwelling omnivorous fish that eats both meat and vegetables.

Crucian carp is a bottom-dwelling omnivorous fish. The best water temperature for feeding is 15-25℃, but it still has feeding requirements when the water temperature is below 10℃.

Grass carp is a mid-bottom layer fish. It is a typical herbivorous fish. Its food intake is the largest when the water temperature is between 25℃ and 30℃.

Black carp mostly inhabits the middle and lower layers of water bodies. Its diet is relatively simple, with mollusks such as snails and clams as its main food.

Tilapia often lives in the shallow water around the pond. It is a warm water fish. Summer is a good season for fishing tilapia.

Freshwater fish are mostly herbivorous and omnivorous, but a small number are carnivorous. In the upper reaches of rivers, they feed on insects and attached algae. In the lower reaches of rivers, they feed on plankton and organic debris.