CATDOLL : CATDOLL: How to transport fish over long distances? Why do fish die during transportation?

1. Long-distance fish transportation technology?

1. Nylon bags filled with oxygen and sealed for transportation

It is suitable for transportation by water, land and air. It is characterized by small size, convenient use and carrying, high shipping density, high survival rate, and can maintain oxygen for more than 30 hours at a time. It is currently an ideal and widely used means of transportation. Commonly used nylon bags are generally 80-100 cm long, 35-40 cm wide, and have a capacity of about 20 liters. After about one-third of the volume of water is injected, a certain number of fry or fish species are put in, the air in the bag is squeezed out, and oxygen is filled in from the bag mouth with a leather tube. Then the bag mouth is folded, tied with a thin rope or rubber band, and placed flat in a wooden box or carton, so that the water and oxygen in the nylon bag have a larger contact surface. The density of fish should be determined according to the water temperature, the quality of the fry and the transportation time. When the water temperature is about 25℃, each bag can hold 50,000 to 80,000 fry, or 5,000 to 8,000 summer flowers. The transportation time does not exceed 24 hours, and there is no need to change water and inflate. The survival rate can reach more than 90%.

2. Inflate and seal plastic barrels for transportation

Plastic barrel transportation is an improvement on nylon bag transportation. Its advantages are that the packaging is not easy to be damaged, no other additional packaging is required, loading and unloading is convenient, it can be placed in overlapping positions, and it is easy to use. It is especially suitable for areas with rugged roads and severe bumps during transportation. Plastic barrels are generally 60 cm long, 40 cm wide, 12 cm high, and have a capacity of about 30 liters. There is an inlet and outlet with a diameter of 5 cm and an injection and exhaust hole with a diameter of 2.5 cm. The hole is equipped with a check valve needle. The inlet and outlet and the injection and exhaust holes are all equipped with push-type inner plugs and bolt outer covers. When used, 15 kg of water is loaded and about 60,000 fry are placed. Inflate 10 to 12 liters. If the transportation time does not exceed 24 hours, the survival rate can reach more than 95%.

3. Canvas box (basket) transportation

Because the box mouth is wide, it is convenient for changing water and feeding, so it is often used for long-distance transportation on cars, trains, and ships. There are two types of canvas boxes, square and round, with wooden and iron frames supporting them. The volume is about 1 cubic meter. There are also larger ones, which are selected according to the transportation situation. When used, three-quarters of the total volume is filled with water. When the water temperature is 20-25℃, the small box can hold 300,000-350,000 fish and 20,000-25,000 summer flower fish; when the water temperature is around 15℃, it can hold 6,000-8,000 2-inch fish or 3,000-4,000 3-inch fish. During transportation, there must be a dedicated person to manage it and pay attention to checking and changing the water.

4. Shoulder transport

Its characteristics are simple tools and low cost, but high labor intensity. Generally, bamboo baskets (lined with oilcloth) or wooden barrels are used. The barrels are filled with water two-thirds of the way, but not too full to avoid overflow. The water in the barrels should be slightly shaken when carrying to increase oxygen. For a journey of less than one day, each load of water is 20 to 25 liters, which can hold 40,000 to 60,000 fry, 5,000 to 6,000 summer croakers, or 1,000 to 2,000 2-inch fingerlings.

2. Why do fish die during transportation?

The main cause of death during transportation is lack of oxygen. The high density of fish (fish) and the limited dissolved oxygen content of the water in the transport container (water) are a pair of major contradictions in transportation.

Any factors that affect the changes in dissolved oxygen content in water and the fish's tolerance to low oxygen will affect the survival rate of live fish during transportation.

Therefore, the methods to improve the survival rate of fish transportation mainly include two aspects in principle:

First, it reduces the metabolic intensity of fish (reduces fish oxygen consumption);

The second is to improve the water quality of the transport water (maintain the oxygen content of the environment). Specifically, the following factors affect the survival rate of transport: fish species, specifications, physical characteristics, water temperature and quality during transportation, transportation time, distance and method, and bumpy road conditions, etc.

3. What should we pay attention to when storing and transporting fresh frozen fish?

The transportation of chilled fish can be carried out by truck or ship in containers such as boxes and barrels, or in bulk in the ship's hold. However, the quality of fish loaded in boxes and barrels is better than that in bulk. The key points to note when transporting chilled fish are:

① The amount of ice should be appropriate, and it should be increased or decreased according to different seasons, transportation distance and time;

②The ice should be clean and the smaller the block, the better. Generally, it is crushed by a plate ice machine;

③ The thickness of the fish piled in the cabin or barrel box should not be too thick. The bottom of the cabin should be padded with planks or wooden strips. There should be small holes at the bottom of the box or barrel to drain the melted ice water to prevent the ice water from soaking the fish body.

4. Introduction to the Movie Resource Network?

Movie Resource Network is an excellent film and television resource website in China. Rich film and television content resources, amazing resource expansion speed, high-speed download, clear playback, clean and simple interface, humanized design, and strong technical backing have all become a strong support for the development and growth of Movie Resource Network.

5. Congratulations from the resource network?

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6. What are the resource websites?

The following are some of the most comprehensive movie download sites:

1. Xunlei Movie Download Network, share the latest movies, high-definition movies, variety shows, animations, TV series and other downloads!

2.6V Movie Network collects the latest movies and TV series on the Internet every day, and provides the latest movie downloads, TV series downloads, high-definition movie downloads and other services for users who use Thunder software.

7. What belongs to the resource network?

The resource network is a collection website that summarizes and summarizes various useful materials, data, articles, pictures, etc. The purpose is to facilitate the public to consult and read, play a role in resource collection and resource inheritance, and make the resources play a better role.

For example, medicine, literature, network, etc. Today's network has spread all over the world, and more and more people are using the network. A large part of the people who go online are looking for resources. Naturally, when someone needs it, the resource network type should be created.

8. What animal doesn’t look like a fish but is a fish?

The lancelet is known as the least fish-like fish.

Amphioxus, also known as Bai's lancelet, slug fish, double-pointed fish or sea hair, is a precious marine animal. Due to its extremely special morphological structure, it has the characteristics of both invertebrates and vertebrates. It is a typical representative of the transitional type from invertebrates to vertebrates. Therefore, it is highly valued by the biological community at home and abroad.

The appearance of lancelet is very strange and interesting. It has a very small body, flattened on the left and right sides, pointed and thin ends, and a spindle-shaped body. It is generally only 4 to 5 cm long.

9. What type of fish is tilapia?

Tilapia - native to Africa, it is a tropical fish. The genus Tilapia includes more than 100 species, including subspecies. Tilapia has the characteristics of fast growth, high yield, omnivorous diet, few diseases and strong reproductive capacity.

10. What are the characteristics of fish?

The shape, body temperature, bones and skin of fish are different from those of other animals. In addition, fish have an organ that other animals do not have - the swim bladder. The existence of the swim bladder is also the reason why fish can float in the water.

1. Shape

Fish have a variety of shapes, sometimes quite different, but in general most fish are elongated and streamlined. Generally speaking, fish that swim fast in the water have elongated bodies, while fish that swim slowly or live at the bottom of the water are relatively flat. But some fish have very strange shapes, such as seahorses. The smallest fish is less than 1 cm, and the largest fish (whale shark) can reach 18 meters.

2. Body temperature.

Fish are cold-blooded animals. The body temperature of some tunas and sharks (especially sharks of the family Carcharhinidae) is higher than the temperature of the surrounding environment. Bluefin tuna is the only warm-blooded fish.

3. Bones

The skeleton of a fish is made of cartilage (cartilaginous fish) or bone (bony fish). There are four to seven gills on both sides of the skull, of which the front one has evolved into the zygomatic bone. The spine of a fish is connected to the skull, the ribs in the chest are connected to the spine, and there are long spines extending from the spine on the back, tail and abdomen.

4. Skin

Fish have two layers of skin: the outer layer contains glands that secrete mucus, and the inner layer contains many connective tissues, scales and pigment cells. The outer layer of mucus helps fish reduce drag when swimming. Cartilaginous fish do not have mucus, but the tiny, tooth-like protrusions on their skin have a similar function.

5. Fish bladder

The swim bladder is an inflatable sac-like organ in the fish's body. Its main function is not breathing. Fish rely on the swim bladder to adjust their specific gravity. Fish can use the swim bladder to slowly rise or descend without moving. Most bony fish have a swim bladder, an organ for regulating buoyancy.