Boleophthalmus Pectinirostris (Linnaeus), also known as jumping fish, mud cows, and flower jumpers. The fish is small, but it is nutritious and delicious. The current market price is about 50 yuan / kg, with a larger breeding development prospects.
First, the morphological characteristics of the large eel catfish individual small, mature individual is generally 80-90mm long, weighing 15-25g; large individuals up to 120-150mm, weighing 30-40g. The body side is flat, the back edge is straight, the ventral edge is lightly curved, the tail shank is taller, and the body and head are rounded. The first dorsal fin is high, the base is short, and there are five fin spines extending in filamentous shape; the second dorsal fin is lower, and the caudal fin base is backward and backward, the pelvic fins are short, the pectoral fins, and the caudal fins are all rounded. Body blue-brown or gray-brown, with 6-7 gray-black stripes along the dorsal pedicle base at the upper part of the body, many bright blue dots spread across the body and head, abdomen white, dark blue first dorsal fin, second dorsal fin blue Gray, pelvic fins yellow, caudal fins grayish black.
II. Habits and diets The large-scale mudskipper is a small fish with warm temperate tropical and coastal waters distributed in Malaysia, North Korea, Japan, South China Sea and East China Sea; Guangdong is mainly distributed in the Pearl River Estuary, Leizhou Bay and other places. Inhabiting salty and freshwater waters in estuaries, near-shore tidal flats, or muddy sediments in low tide areas are resistant to harsh water quality. Wide-salinity, hi cave dwelling, the hole is generally Y-shaped, consisting of a hole, a positive orifice, and a posterior orifice. Positive orifices are used for access, and rear orifices are used for ventilation. Rely on the pectoral and caudal peduncles to crawl or jump on the water, on the beach or on the rocks. Apply to the mud to feed benthic diatoms, blue-green algae, and eat a small amount of copepods and organic matter.
Third, breeding and growth The breeding season of the big blisters is from April to September every year, and each broodstock can spawn about 10,000 eggs. The eggs are spherical and sticky yellow. In summer and autumn, a large number of fry can be seen in the estuary where the seawater has a specific gravity of 1.10 or less. The growth rate is slow, and it usually takes 1-2 years from seedlings to adult fish.
IV. Farming and Fishing The culture of big-bolted fish has long been popular in some areas of Taiwan and Southeast Asia and is still relatively rare in mainland China. The structure of the pool for big bunting fish is roughly the same as that of Milkfish. The bottom of the pool should generally be higher than the low tide line and must be flat. The bottom quality is better with clay; the water depth in the pool is more appropriate than 5-15 cm, and the depth is not conducive to growth; the salinity of the pool water It is between 1.010-1.20; when the water temperature is 24°C-30°C, it grows faster; before the fry is released, it must be used to dry the floor, apply the base fertilizer, disinfect it, drive away the miscellaneous fish and predators, and then inject water to cultivate the algae. The fry stocking time is generally from June to September, and the stocking amount for each public item is usually 30,000. The growth rate of big salamander fish is related to the pond environment, algae conditions, and management techniques. The fishing harvest time is 1-2 years.
Large catch fish can be caught by hand catching method, cage catching method and hanging net method. Hand catching method is a catcher who finds a fish hole and then directly grabs it along the tunnel. The disadvantage is that the catch or survival rate is low. The cage trapping method is to catch the fish hole after the catcher, close the hole with mud, use the mouth of the fish cage to insert it into the positive hole, wait until it is out of the hole and enter the fish cage and capture it. The method of hanging nets is to use the habit of large eel-bowl fish tidal water, first drain the pool water to 2cm shallow or drain the pool, and set up the hanging net at the water inlet of the fish pond, and use the water at the high tide to inject water slowly. The large-scale mudskipper will cluster into the net and pull it into the net. The net rope lifts the catch.
V. Breeding and Breeding of Bullet Fish
(1) Breeding pond structure Use the original bomb-bearing culture pond with 17 mu, the water depth is 50-80cm, and the bottom sediment is sediment. There are several rows of digging trenches in the pool, digging one trench at intervals of 2m. The specifications of each trench are: trench width of 1m and trench depth of 30-40cm. Formed around the ditch around the ring cloth, and the pool of water to open up each other unimpeded. The entire nursery pond is rectangular, and the two sides of the pond are slightly deeper, which is conducive to the collection of fish, fish, and fish. A cylindrical tube made of ceramics is placed at intervals of 2 m in the ditch, with a diameter of 10 cm and a length of 50 cm.
(B) The choice of broodstock
1. Source of broodstock: At present, in the coastal waters of Fujian Province, it is difficult to purchase broodstock of the size and can be used for the mass production of shellfish fry, and the broodstock is mainly from Taiwan. Introduce artificially cultivated broodstock older than 2 years old from Taiwan. Select disease-free and non-invasive large individuals, generally require body length 20-23cm, weight 160-200g.
2. Broodstock transport: 200 broodstock were purchased directly from Taiwan's eel-bearing fish seed farms, of which males accounted for 10%. The use of plastic film bags filled with oxygen packaging, every 4 parent fish loaded 1 small bag, shipped from the Taiwan port to the breeding nursery for a total of 10 hours, the survival rate of 98%.
3. Identification of male and female: Ectoplasma hermaphroditic, broodstock identification in the non-breeding season is difficult. In the breeding season, from April to September each year, males and females can be distinguished from the appearance of their blowholes in the breeding season: the female fish has a red, round and round fish body, the fish body is plump, the ovary is yellow, and the eggs are sticky eggs; The vents are narrow and prolonged to be pointed and the fish body is elongated.
Third, the development of broodstock broodstock before entering the pool should do a good job in cultivating the sun pool pool, remove the enemy and other clearing pool disinfection work. Each cubic body of water can be disinfected with a 1.5g bleach solution pool. On June 15th of that year, the broodstock was sterilized with penicillin for 4 to 5 minutes and then it could be put into breeding ponds. Pool water temperature of 27 °C a 28 °C, the proportion of l. 013. The initial feeding of broodstock was dominated by benthic diatoms in breeding ponds, after which rice bran and biosynthetic hormone (Taiwan products) can be fed. To keep the water fresh and rich in dissolved oxygen, it is generally not necessary to feed it every day. The amount of water to be changed per day depends on the weather conditions. It is advisable to promote the development of gonads with microfluidic water.
(d) Spawning and hatching of broodstock After intensive breeding and cultivation for more than 1 month, neither artificial ripening by artificial glands nor artificial hormones has been used to elicit gonads. Gradually the gonads gradually mature in the hatchery until July 29. The first batch of spawnings took place on the day (multi-lot spawning). The spawning period lasted 16 days and ended on August 14. After random sampling and counting, more than 330 million eggs were laid, and the average number of broodstock spawning was l. 50,000 tablets. The proportion of pool water during incubation l. 013, water temperature 26°C-27°C.
(e) Breeding of fry The fry can be hatched on the fourth day after spawning of each batch of broodstock. The newly hatched fry mainly feed on floating plants and animals in breeding ponds, supplemented with appropriate amount of soybean milk, and sprinkled and fed twice a day to supplement the deficiency of natural food. Changing the water once a day, changing the amount of water is 30% to 50%. After 60-70 days of intensive cultivation, the body length of the fish is generally more than 1cm, and the survival rate is 45%. A total of more than 1.5 million seedlings have been cultivated.
(f) The seedlings are transported using plastic film bags filled with oxygen. One-third of the bagged water is put into 5,000 pieces of fish with a body length of 1cm.
Sixth, the big bunting fish artificial pool raising technology
l. The selection of the pond requires that the ground be flat, and that the bottom of the pond should be higher than the low tide line, so as to facilitate fertilization and sun drying to promote cultivation of benthic diatoms and breeding. Each aquarium is equipped with a water inlet gate and a water outlet gate. The ground floor should be slightly inclined towards the gate, and a gutter with a width of about 2m should be opened in the center to connect the gate for smooth drainage. In order to make holes for the infestation and propagation of algae, the bottom material should be soft clay. The pond outside the pond should be higher, and conditions can be added to a fence to prevent fish and wild animals from invading. The pond area is generally 7-8 acres.
2. Before clear ponds and sterilized stocking, they should be exposed to the bottom of the pool, remove predators, etc., and then soaked in water, combined with the use of bleaching powder disinfection, with 1.5g bleach solution per cubic meter of water. Newly-cultivated aquaculture ponds can be applied with 4kg of agricultural manure fertilizer per acre, and water depth of 6-8cm is appropriate.
3. The seedlings are sourced from artificial nursery or natural seedlings, and the time for collecting natural seedlings is from June to August. The catchers can use small hand-operated nets for fishing. Or buy seeds directly from Taiwan.
4. Putting seedlings and densities for the purchase of large eel-bearing fish seedlings with a density of 5 cm or more is generally carried out in April after each year. The seedling density is generally 3000-5000 tails/mu. If the density of seedlings is more than 5000 tails/mu, the supply of algae in the pond may be insufficient, and growth may be slowed down.
5. After fertilization and feeding for a period of time, the benthic diatoms in the pond have basically disappeared and the water quality begins to become cloudy. At this time, drainage, sun drying and fertilization should be promptly conducted to promote the reproduction of benthic diatoms. In terms of feeding, when the seedlings were first released, they were fed once a week, each time 50 kg of rice bran was fed per acre, and 2 kg of feed additive was added. Pool water depth is maintained at 8-10cm. After breeding for 45 days, when the body length is about 5-7 cm, a deeper hole should be built. When the temperature is high, choose to drain the pool water on a sunny day, leaving some water in the ditch, sun 3-5 days, depending on the bottom of the pool is slightly harder to fertilize the water. Rice bran, until the bottom of the pool sun to crack like, inject fresh water 5 l0cm. One week later, adherent diatoms continue to multiply.
Note: Regardless of the application of feces, water and fertilizer, should not directly flow into the channel, it is best to use mixed feces and water and fertilizer, and after the application of water dilute and then injected, so as not to stimulate the large salamander fish inhabit the hole and cause death.
6. Day-to-day management First of all, when the weather is calm and sunny, drain and dry the pool. In case of cold winter cold, multiple water injections are suitable for maintaining water volume. Secondly, we must pay attention to the use of pesticides and prevent predation and other hazards of ferocious fish, birds, crabs, and conch species, such as sea otters.
7. Harvesting and shipping fishing methods: drain the pool water, maintain the water level of the ditch, and look for the entrance and exit points of the big mudskipper fish. All imports have fish traces. Take the wet mud and close the mouth and align the fish cage with the mouth so that the fish can be automatically caught in the fish cage from the entrance.
The livelihood of the giant salamander is easy to transport. It uses a special circular sieve tray with a diameter of 80cm and a depth of 20cm. The bottom of the sieve tray is covered with a layer of plastic film. Put the commercial fish into the sieve tray and add a small amount of water. This will put several sieve trays into the fish and complete the packing task. Delivery destination within 2-3 days, the survival rate can reach 100% for sale.
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