Cage culture for fish is the most common culture. No doubt, cage culture for fish is the longest and oldest form for cage culture. In this article, we are going to show you the most important 3 factors regarding cage culture for fish.
1. Filter feeding fishes
Silver carp and Bighead are currently the mail species of cage culture. People use natural bait in the water to breed. It has the advantages of small investment and no pollution. Meanwhile, it has the advantage of good efficiency, good quality and safety.
Silver carp and Bighead are typical filter-feeding fishes. They grow fast. At age 2~3, their weight can be increased from 1 kg to 4 kg. The maximum can reach 40 kg. Natural production is very high. The main technical points are as follows.
(1) the structure and setting place of culture cage.
Generally, people should select floating closed cage. The cage should be placed near the farmland. The water should be shallow, fresh and oxygen-rich. The flow rate should be 0.05 to 0.2 meters per second. If the rate is too high, it will consume fishes’ energy. It will be harmful to fishes’ growth.
(2) the layout of culture cage.
To scale the culture, the cages cannot be too dense. Otherwise, it will make the feed shortage. In general, each cage should be kept at 5~20 meters from another. It can smooth and increase the water.
(3) Rinse the cage frequently
For cage culture, the feeding mainly depends on the plankton in the water. Thus, it is very important to keep the water smooth and the net clean to keep good water efficiency.
2. Herbivorous fishes
The main species of herbivorous fish in cage culture are grass carp and bream. It has the advantage of high yield and high benefit. It also has the disadvantage of high disease risk. For grass carps, the fastest length growth is 1~2 years old. The fastest weight growth is 2~3 age. After 5 years the growth becomes slower. The main technical points are as follows.
(1) the selection and location of the cage.
Generally, the fixed open net cage is preferred. The size of the cage should be more than 60 square meters. The net should be at least 40 centimetres above the water. It can prevent the fish from jumping out.
(2) the layout of the cage
For herbivorous fish culture, a large number of feeding is required. Hence, the water exchange should be smooth. The cages should be scheduled in order. The distance between each column is about 15 meters. In each column, there are about 3.5 meters between each cage.
(3) Fish feeding
At present, most cage culture mainly depends on commercial bait. Meanwhile, people supplement with some forage. When feeding commercial materials, the daily weight should be 3% to 5% of fish weight. Keep it 3~4 times per day.
(4) daily management
We should keep checking cages and fish growth every day and writing fishery log. Find the damage net and repair in time. Keep the fish from escaping and enemy fish away. In the flood season, we should check the ropes and net. Wash the net cage every 10~15 days. Remove residual bait and algae attached. Make the water exchange.
3. Cage culture for fish – carp culture
Cage culture of crucian carp has many long history and mature technology. Its main technical points are below.
(1). Net cage structure
The cage should be in rectangular shape with polyethylene mesh. The measure is generally 20~30 meters square and 2~3 meters high. Mesh should be 3 centimetres, according to fingerling size.
(2). Bait and feeding
Feeding depends on the weather, water temperature and fish eating. If the water temperature is below 18-degree centigrade, the daily feeding should be 1% to 3% of fish weight. Make it into 2 times per day. If the water temperature is above 18-degree centigrade, the daily feeding should be 3% to 5% of fish weight. Make it into 3 to 5 times per day.
(3). Daily management
According to the water and mesh, people should clean the cage in time. The dead fish and dirt should be removed from the cage in time. Watch the fish eating and acting every day. Sterilize frequently. It is usually 1 times per month.
(4). disease prevention and control
(a) carefully operate to avoid the fish injury
(b) Strictly sterilize the fish before putting into cage.
(c) Regularly disinfect the water
(d) Find out the dead fish in time.
(e) The fishing gear should be disinfectedused.