Daily Management of Pelteobagrus fulvidraco cultured in Cage

The daily management of raising Pelteobagrus fulvidraco in cage includes cage inspection, fish growth inspection, cage cleaning and disease prevention.

I) routine inspection

The routine inspection includes cage body inspection and fish growth inspection.

1. Cage body inspection net cage body inspection has before and after the fish seed inspection and the feeding process inspection, these two kinds of inspection are very important. After the fish are released, check the box once every morning and evening to see if the net coat is damaged. The method of inspection is to slowly lift the four corners of the cage in turn to carefully check whether the net coat is damaged, whether the mesh is bitten by water rats, whether it is punctured by back and chest, and whether the box is damaged during operation. Find the problem and fix it in time. In order to prevent fish from escaping from breaking the net, it is generally in the form of double-layer cages. When inspecting, check the inner cage first, and then check the outer cage.

two。 Fish growth inspection in the box because the cage culture of Pelteobagrus fulvidraco should be reared by stages, and the important basis of graded breeding is whether the fish growth reaches a certain stage. Only through regular inspection of fish can we grasp the growth of fish, which not only provides a practical basis for feeding, but also provides reliable data for yield estimation. Growth inspection is generally required to be checked every 5-7 days in the early stage and every half a month in the later period to analyze the existing problems and take corresponding measures in time. The method to check the growth of fish is to pick up the Pelteobagrus fulvidraco from the cage with a net, put it into a small basin and bucket, and measure the fish with a ruler. At the same time, the fatness of the fish should be observed in order to adjust the feeding in time.

II) cleaning of dirt in the box

Generally speaking, 3-5 days after the cage is launched, a large amount of dirt will be attached, and then living algae such as sponges, double-star algae and turn-plate algae will be attached to block the mesh, thus affecting the exchange of water bodies inside and outside the cage, which is not conducive to the culture of Pelteobagrus fulvidraco. In this case, manual cleaning must be carried out. At present, there are the following methods of cleaning net clothes in cage fish culture in China:

1. When there are few attachments on the cage manually, you can first lift the net coat by hand, and then shake off the dirt, or directly immerse the net coat in water and scrub. When there are too many attachments, you can scrub with a hard brush, or directly immerse the net coat in water and beat it with a piece of bamboo to shake it off. The operation should be careful to prevent fish injury and net breaking.

two。 When the scale of the cage is large, the mechanical cleaning can make the spray gun and submersible pump wash down the dirt on the net coat with a strong current.

3. In caisson method, all kinds of filamentous green algae are generally difficult to grow and reproduce at a depth of less than 1 meter. Therefore, by sinking the enclosed cage to 1 meter below the surface of the water, the attachment on the net can be reduced. However, this method often affects feeding and management, which is disadvantageous to the growth of fish, so it is necessary to adjust measures to local conditions and weigh the pros and cons before making a decision.

4. Biological cleaning method makes use of the habit of scraping epiphytic algae, swallowing filamentous algae and organic detritus in fish such as mackerel (such as fine-scaled oblique jaw mackerel and yellow-tailed mackerel). Let them scrape and eat the organisms attached to the cage to keep the net clothes clean and the water flowing smoothly. The use of this biological dirt removal can not only make full use of the bait organisms in the cage, but also increase the species of culture and improve the fish yield and economic benefits.

III) disaster weather management and log recording

1. Disaster weather management disaster weather mainly refers to strong winds, rainstorms and floods. Strong winds are often accompanied by rainstorms, and cages set in lakes and large waters sometimes overturn or be submerged by wind and waves, so it is necessary to check whether the frames and pillars of the cages are strong before blowing strong winds. The fixed cage should strengthen the rope and appropriately increase the height of the exposed part of the cage. The floating cage should prevent the bottom of the cage from being close to the bottom of the lake during the strong wind, in case the wire is broken and the net is broken due to friction. The flood can accelerate the flow of water in the setting area of the cage, causing the cage to fix the pile and shift the anchor of the floating cage, and the rise of the water level can make the fixed cage have no top to escape fish, and cover the open cage if necessary. No matter strong wind, rainstorm or flood, it should be checked immediately after that, and once a problem is found, it should be repaired and rescued immediately.

two。 Keeping in mind the breeding log is an important reference for checking work, accumulating experience, making plans and improving techniques. To carry out scientific fish farming, we must keep a good record of the log of each cage, which is the most basic management work. The cage log should include date, weather, water temperature, stocking, fishing records, records of fish body length, species and quantity of feeding, fish activities and fish disease prevention measures, etc. Analyzing the problems according to the log and summing up the experiences and lessons is an important link in the smooth development of cage culture of Pelteobagrus fulvidraco.