Seafood live transport and the method of temporary feeding

Before the live transport, first of all, we must realize that the transport of the object in the transport of the environment is different from the original living environment. Due to the significant difference in the environment, will make the physiological condition of the living body changes. Serious threat to the survival of the living body, directly affecting the survival rate of transportation. Here we analyze the main factors affecting the physiological condition of the live aquatic products during transportation: oxygen, temperature, carbon dioxide, ammonia and nitrogen.

1, oxygen

Insufficient oxygen will make the seafood aquatic products in the transportation process can not breathe normally, if a serious lack of oxygen, but also cause its asphyxiation death, thus affecting the survival rate. General transportation, the dissolved oxygen in the water should be maintained at 5mg / L or more. For this reason, it is necessary to ensure the supply of oxygen during transportation. There are several ways to supply oxygen.

① Transportation often injected with good new water, can increase the oxygen content of the water. The temperature and salinity of the new water is generally similar to the old water.

② moderate oscillation of the transporter, so that the water fluctuations, in order to increase the contact surface of the water and air, increase dissolved oxygen. Be careful that the transporter can not be shaken too violently, so as not to harm the fish.

③ Set up some mesh plates on the surface of the water in the transporter, so that it is constantly turning back slowly to increase the oscillation of the water.

④ In the transportation process to install the oxygenator or aerator, can be at any time to increase oxygen.

⑤ Pure oxygen can be supplied.

2, temperature

Fish and other variable temperature animals, body temperature changes with the water temperature changes. All kinds of aquatic products have their own temperature range, beyond the temperature range is easy to die. In the transportation process must control the water temperature. High temperature, the organism's metabolic rate and oxygen consumption and the resulting carbon dioxide and ammonia content is also high; at the same time, the dissolved oxygen is reduced, so that the organism's affinity for blood and oxygen is also weakened. Therefore, when changing water, adding new water or adding ice, it is necessary to prevent rapid and sudden changes in temperature. Sudden changes in water temperature, the internal functions of the fish body can not immediately adjust to adapt to this change, the fish are prone to disease. If the temperature is too high in summer, you can put some crushed ice on the surface of the water to make it melt gradually, which can lower the water temperature. If the water temperature is too low in winter, anti-freezing measures should be taken. Changes in water temperature, generally to the temperature difference of not more than 5 ℃ is appropriate.

3, carbon dioxide

Fish breathing in the water will discharge carbon dioxide, so that the concentration of carbon dioxide in the water increases. It has been confirmed that the harmful concentration of carbon dioxide to fish is 60~100mg/L. At this time, even if the dissolved oxygen in the water is saturated, the fish still can not breathe normally, and will die of asphyxiation. During general transportation, the concentration of carbon dioxide contained in the tank is 20×10-6 to 30×10-6. If the concentration of carbon dioxide exceeds this range, the water should be inflated to exclude carbon dioxide and increase the dissolved oxygen in the water to maintain a normal living environment for the fish.

4, ammonia

Due to the feces, bait, dirt and bacteria discharged by fish and shrimp, the content of ammonia in the water is increasing. When the ammonia in the water accumulates to a certain concentration, it will weaken the ability of the fish and shrimp to absorb oxygen, and prevent the normal respiration of the living body. Ammonia is very harmful to fish, generally the concentration exceeds 0.012×10-6 when the fish have caused the danger. Usually when the water temperature rises, the ammonia discharge of fish increases, and the ammonia discharge of small fish is more than that of larger fish. So the transportation should be a large number of supplemental oxygen, so as not to kill the fish midway poisoning, resulting in losses.

5, the osmotic pressure of the organism

Fish, shrimp, etc., the surface of the body has a secretion of mucus or scales, which can maintain the osmotic pressure balance in the body. In the process of transportation, due to the vibration of the transport equipment, fish, shrimp and other body surface will often be subject to water tanks or nets and other instruments of mechanical bruising, resulting in scales and mucus off, skin abrasion, so that the body of osmotic pressure is out of balance, reducing the resistance of the fish to disease. So the damage to the surface of the fish body should be minimized or avoided to maintain normal osmotic pressure.

6, the organism's physique

Before transportation, if the fish, shrimp and other organisms are robust, the ability to adapt to adverse environmental conditions, the survival rate of transportation is high. When seafood and aquatic products are captured and put into the transportation equipment, due to the new environment is not adapted to or frightened, will be swimming and struggling fiercely, so the muscles will be contracted. At this time, if there is not enough oxygenated blood to replenish, will produce a large number of lactic acid accumulation in the muscle blood vessels, the blood pH value is reduced; due to the acidic blood to the lower utilization of oxygen, fish, shrimp, etc. within 24 hours is not easy to return to normal. The speed of its recovery depends mainly on the type of organisms and body mass, so before transportation must be selected robust individuals to ensure the survival rate.

7, to prevent the propagation of bacteria

Seafood and aquatic products in the transportation process if in an uncomfortable environment, there will be a large amount of secretion of mucus and excreta. These secretions will become the culture agent of bacteria, so that the germs are large and rapid reproduction. --- On the one hand, germs will make seafood infected with disease; on the other hand, the growth of germs to consume oxygen, reducing the content of dissolved oxygen in the water, easy to make the seafood due to lack of oxygen and death.

In addition, in the process of transportation, if the fish's digestive tract left residual food, bacteria will also enter the intestines and stomach with a large number of reproduction, coupled with the transportation of the fish itself is physically weaker, more susceptible to infection disease. In order to improve the survival rate of the transport, seafood in the transportation of the temporary breeding, we must first "eliminate the belly", discharged feces, so as to avoid or reduce the transport of water pollution and deterioration, improve the survival rate of seafood.