CATDOLL : CATDOLL: What are filter-feeding fish? What are filter-feeding fish?

1. What are filter-feeding fish? What are filter-feeding fish?

Filter-feeding fish: A general term for a class of cold-blooded vertebrates that live in water all their lives, breathe with gills, use fins to assist body balance and movement, and feed on plankton. The most common types of filter-feeding fish are silver carp and bighead carp, two of the four major carps. Silver carp is a filter-feeding fish that mainly feeds on phytoplankton, while bighead carp is a filter-feeding fish that mainly feeds on zooplankton. Both types of fish are particularly suitable for breeding in northern waters, where they grow fast and are used in large quantities.

2. What are filter-feeding fish?

Filter-feeding fish are a type of fish that use their gill rakers to filter tiny plankton, bacteria, organic debris, etc. in the water. Representative species include silver carp and bighead carp, which are traditional farmed fish in my country. The most common filter-feeding fish are silver carp (Hypophthalmichthys molitrix) and bighead carp, two of the four major carps.

3. What does filter-feeding fish mean?

Filter-feeding fish are a type of fish that use their gill rakers to filter tiny plankton, bacteria, organic debris, etc. in the water. Representative species include silver carp and bighead carp, which are traditional farmed fish in my country. The most common types of filter-feeding fish are silver carp and bighead carp, two of the four major carps.

Filter-feeding fish, also known as fat-water fish, feed on plankton and organic debris in the water by filtering them. They have specialized filter-feeding organs, mainly composed of gill rakers, gill raker tubes (branchial organs), palatine folds, and gill arc bones.

4. Can filter-feeding fish eat Microcystis and Anabaena?

Microcystis and Anabaena are some common cyanobacteria. They will reproduce in large numbers in some natural waters and may produce some toxic metabolites, which may cause some harm to aquatic organisms and human health. Therefore, in general, it is recommended not to let filter-feeding fish (such as carp, black carp, etc.) eat aquatic products that may be contaminated by Microcystis or Anabaena.

For these cyanobacteria, their main toxic components are microcystins and anabaena toxins. Different cyanobacteria will produce different types and amounts of toxins, which can have different degrees of toxic effects on various organisms. Some filter-feeding fish may be able to eat some contaminated algae or other toxic organisms in moderation, but if they eat too much algae or other toxic organisms, it may be toxic to the fish and eventually be excreted or die.

Therefore, in general, we recommend that filter-feeding fish not eat aquatic products contaminated by Microcystis or Anabaena to avoid potential food safety issues. If you are unsure whether a certain fish is safe to eat, it is recommended to consult relevant professionals or local fishery production management departments.

5. What is the cage farming technology for eels?

The cages for breeding yellow eels are preferably made of polyethylene knotless mesh with a mesh size of 10 to 36. The cages are preferably 6 meters long, 2 meters wide, and 1 to 1.5 meters high. They can also be flexibly adjusted according to the size of the pond, but the width should not exceed 3 meters. A cover net is set on the cage. The four corners of the cage are fixed with wooden stakes or bamboo. The upper edge of the cage is 70 to 80 cm above the water surface, and the cage body is 60 to 70 cm into the water. The cages are arranged in a single row or multiple rows, with each row 2 to 4 meters apart. The cages should be put into the water 10 to 15 days before the eels are put into the cages to facilitate the formation of algae biofilm on the mesh and avoid friction and injury of the eels.

Do not feed the eels in the first three days after stocking. Start feeding on the fourth day, usually in the evening. Make a pulp with 60% to 70% fresh bait, add 30% to 40% compound feed, mix well and leave for half an hour, feed 1% of the eel's body weight on the feeding table in the cage (one feeding table is set up for every 6 square meters of cage). Generally, after 2 to 3 days, the eels will become benthic fish with strong adaptability and more resistant to low oxygen. They mostly live in the bottom soil of rice fields, ponds, ditches and lakes. They hide during the day and come out at night, foraging for food.

6. What is the technology for farming eels in cages?

1. Select good seedlings, choose eels with long, thin and elastic bodies, generally use seedlings weighing about 60 grams.

2. Prepare the net cage. Generally, choose a basket cage or net cage with a size of 1 meter * 0.8 meter. The mesh size should be determined according to the size of the eel, generally about 4-6 centimeters.

3. Select good fermented feed. Since the eel is a carnivore, the feed should mainly consist of various rice worms, turtles, and small fish. Among them, the best is the Chaofeng worm, which has good digestibility and high nutritional value.

4. Prepare the feed, put the eels into baskets and nets, and feed them an appropriate amount of feed, 2-3 times a day. The amount of feed given each time should not exceed 10% of the eel's weight from sunrise to sunset during the day.

5. Reasonable management: The water quality of the cage must be tested regularly. If the water quality is too poor, it needs to be replaced and cleaned in time. At the same time, a certain water temperature and water flow must be maintained.

6. Long-term nutritional and healthy breeding, regularly feeding eels with some vitamins and enhancers can improve their disease resistance and immune function.

It should be noted that when farming eels in cages, it is necessary to carefully guard against diseases, pay attention to the feed situation, and pay attention to changes in water quality and temperature, so that the eels can be farmed in cages smoothly.

7. Fish breeding techniques?

1.

Stocking time selection: Fish should be released on sunny days when the temperature is not too low. Generally, the temperature should be between 2℃ and 5℃. At this stage, the fish scales are tight and the activity is small. It is not easy to injure the fish during fishing, transportation and stocking operations, which can reduce the morbidity and mortality of fish. It is easy to frostbite the fish on rainy days with low temperature or snowy, frozen and windy weather; when the temperature is too high, the fish scales are loose and the activity is large, which is easy to injure the fish during operation.

2.

Stocking of fish: Before stocking the fish, check whether the drugs have lost their effectiveness after pond cleaning. In early spring, the water temperature is low and the toxicity disappears slowly. Water should be taken in advance and test fish should be released. According to the stocking plan, individual size, density, and matching species and specifications, the fish that can be released at one time should not be released in batches, so that the fish can adapt to the environment, start eating early, and promote growth. At the same time, [Gold Iodine] should be used for drug disinfection when stocking fish.

3.

Feeding at the right time When the water temperature rises to 810℃, fish begin to eat, and the amount of food intake gradually increases with the increase of water temperature, so they should be fed in time. Feed once a day or every other day, and choose to feed at noon on a sunny day; as the water temperature continues to rise, the number of feedings can be increased to twice, that is, feeding once in the morning and once in the afternoon. Feeding should adhere to the principle of four determinations (timing, quality, positioning, and quantity), and the specific daily feeding amount should be flexibly controlled according to the weather, water temperature, and the feeding situation of fish. For grass carp weighing more than 1 jin, it is recommended to feed Da Beinong high-grade expanded feed 8103 in the early stage of feeding; for small grass carp mode, it is recommended to feed Da Beinong microecological juvenile fish special feed [Intestinal Liver Health], and the feeding rate is controlled at about 0.5%1%. This product is rich in nutrients and probiotics, which can quickly repair the fish intestines, restore the physique, and improve immunity.

Four,

Add organic fertilizer to improve the fertility of the water body. Sanyingshuiwang organic biological fertilizer has a long-lasting fertilizer effect. Yizaoyuan promotes algae growth and quickly fertilizes the water. After the fish pond is cleaned, frozen, and disinfected in winter, the fertility of the water body is low. As the saying goes, raising fish starts with raising water, so fertilizing the pond water is particularly important. In spring, it is best to apply organic fertilizer. It is recommended to use biological fertilizers rich in various trace elements [Sanyingshuiwang] or Yizaoyuan, which are rich in trace elements. The specific amount of fertilizer and frequency should be determined according to the quality of pond water and fertilizer.

The general principle is: early spring, large amount and few times, late spring, small amount and many times. Make the pool water green (including blue-green, yellow-green and bean green) or brown (including yellow-brown, reddish brown and tea-brown), the water transparency is moderate, maintained at about 30 cm, the water temperature is low in early spring, it should be controlled at 20-30 cm, the temperature is high in late spring, it should be controlled at 25-35 cm, the water quality should be kept rich, active, tender and refreshing.

8. What is the largest predatory fish in the world?

The largest predatory fish in existence is the great white shark, and killer whales are not fish.

9. What is the density of water splash fish fry cultured in cages?

Generally, there are 200,000 to 300,000 fish per acre, and they can be cultivated to a size of about 3.3 cm, which is the most standard stocking density of water flower fish fry.

In order to save time and quickly grow large-sized seedlings (for example, 0.1-0.5 catties/fish), 50,000 to 70,000 water flower seedlings are stocked per mu;

If you cultivate seedlings over 7 cm (2 inches) at one time, you can stock 100,000 to 150,000 water lilies per acre.

If you plan to sell small-sized seedlings or divide the pond in advance, you can put 800,000 to 1 million per mu. You must sell them after the black cucumber seedlings (1 to 1.5 cm) or divide the pond when they are cucumber seedlings (2 to 2.5 cm).

10. What are the quality requirements for farmed fish?

1. Fish species

1. Different species of fish have different protein and fat content in their muscles, different meat structures, and large differences in price.

2. Different species of fish have different contents of amino acids that make up the protein in the fish meat, such as lysine, arginine, glutamic acid, aspartic acid, alanine, etc., and the taste is also different.

3. The types and proportions of fatty acids in fish fat, especially the proportion of docosahexaenoic acid (DHA), also vary, resulting in different tastes of fish.

4. DHA is a natural melatonin and an essential nutrient for the human body. Fish with high DHA content include tuna, bonito, salmon, mackerel, etc.

5. The content of the above-mentioned amino acids and DHA in the muscles of marine fish is higher than that of freshwater fish, so marine fish tastes better than freshwater fish.

6. In aquaculture, the selection of breeding species must meet the following conditions: choose suitable breeding species based on the local breeding environment and climatic conditions; examine whether they have market development prospects; the selected breeding species must not have any difficulties in terms of seedlings, feed, etc.; be able to master the feeding and management techniques of the breeding species, and invite breeding experts for regular guidance, etc.

2. Aquaculture water environment

1. Aquaculture requires sufficient water resources, fresh water quality and no pollution.

2. First, establish a farm in a place with sufficient water resources, up-to-standard water quality, convenient irrigation and drainage, and convenient transportation. Secondly, cultivate good water quality. During the breeding process, pay close attention to changes in water temperature, transparency, dissolved oxygen, pH value, etc. to ensure that the water quality always remains "rich, active, tender, and refreshing."

3. Feeding

1. Feed is the material basis for farmed fish to survive. The balance between protein, fat, carbohydrates and vitamins in the feed is crucial. Fish eating high-quality and fresh feed can improve their physiological state and immunity, and increase their survival rate. Fish farmed in this way have good color, normal body shape, strong vitality, firm fish meat and good taste.

2. Feed feeding: select palatable, high-quality, fresh feed according to the physiological characteristics of fish, and strictly follow the "four determinations" principle for scientific feeding; adjust the feeding amount in time according to weather conditions and fish feeding conditions; make full use of the breeding space of the water body, adopt a mixed breeding method of multiple varieties, rationally utilize the natural bait and artificial feed in the water body, improve the breeding water environment, and improve the breeding efficiency.

4. Use of fishery drugs

1. In the process of aquaculture, when cleaning ponds and disinfecting, seedlings and feeding tools, and adjusting water quality, the selection of fishery drugs should be scientific and reasonable, and special attention should be paid to the usage and dosage to prevent the quality of farmed fish from being affected by improper use of drugs.

2. The use of fishery drugs should be based on different aquaculture species and different pathogenic factors. Appropriate national standard fishery drugs should be selected, and treatment should be carried out according to the prescribed dosage, usage method, and course of treatment, and the regulations on drug withdrawal periods should be strictly implemented.

3. In breeding, we should start from the nutritional needs of animal growth, feed hygiene, breeding management and other aspects to reduce the occurrence of diseases and ensure human food safety.