Detailed Explanation of Key Points of Octopus Artificial Breeding Technology
The octopus is a temperate-zone mollusk that lives underwater. The water temperature it can tolerate must not be lower than 7°C, and a seawater specific gravity of 1.021 is most suitable. It will die in low-salinity environments. It is widely distributed in tropical and temperate seas around the world, and is found along the coasts of both northern and southern China. The fishing season is divided into spring and autumn: spring from March to May, and autumn from September to November. Now let us take a look at octopus artificial breeding technology!
Octopus Plastic Bottle Culture
Octopus plastic bottle culture uses wild juvenile octopuses placed in discarded 500 ml beverage bottles with small holes punched in them. The bottle mouths are sealed, and the bottles are strung together with rope and hung in the sea for natural hanging culture, with floating balls added at appropriate intervals, achieving relatively good results. Although this method is simple, the octopus grows relatively slowly, so it is suitable for culture in sea areas rich in plankton.
Concrete Pond Culture Method
The concrete pond culture method uses 8 concrete ponds of about 20 sq m each and 80 cm deep. The pond bottom is covered with 20-30 cm thick sea mud (50 cm thick in the center of the pond), and settled seawater is added. Octopus juveniles dug and caught from tidal flats, 10-50 g in size (average about 40 g), are stocked. They are fed once every afternoon, and the feed is live small crabs dug and caught from tidal flats (individuals 2-6 g, average 300 per kilogram). Indoor light is between 800-1000 LX. During the culture process, settled seawater is used to change the water once a day. As long as water is changed attentively during high-temperature seasons, octopuses generally will not die. After about 6 months of rearing, the individuals generally reach 50-100 g (average about 70 g) before harvest. This method is simple and easy to carry out, with low technical requirements, and is suitable for small-scale household culture.
Octopus Seine Net Culture
Octopus seine net culture is carried out by enclosing about 3000 sq m with fine-mesh netting on tidal flats in the middle and high tide zones to culture octopuses. When the tide recedes and the flats are exposed, the octopuses hide in burrows, but the net panels of the enclosure must be higher than the highest tide level to prevent escape. This method is simple and low in cost, but at harvest time the digging and catching area is large and labor-intensive.
Octopus Cage Culture
1. Cage setup: Cage culture can be used (3.94 m × 1.82 m × 0.9 m, with mesh smaller than the individual fry; a net cover must be added to prevent octopuses from escaping; mostly carried out in calm bays with waves, and the suitable water temperature is 15-23°C. Under normal circumstances, culture is mostly carried out in spring-summer (June, July) and autumn (October-December).
2. Seedling stocking: Octopus seedlings caught by traps are the most suitable, and those caught by bottom trawls can also be used. The stocking amount varies depending on water temperature and water flow conditions. Large cages are stocked with 36-42 kg of seedlings per l cubic meter, and small cages are stocked with 25-30 kg of seedlings per l cubic meter. To prevent seedlings from killing each other, the same batch of seedlings should be stocked. It is best to put the seedlings into the cages after they are fully fed.
3. Feed feeding: Low-priced small miscellaneous fish and shellfish can be given, and frozen small miscellaneous fish can also be given, but they must be fresh. When there is a lot of leftover feed, it is best to reduce or stop feeding for l-2 days. Leftover feed will cause water quality pollution. If feeding is stopped for more than 3 days, they will kill each other. At a water temperature of about 13°C, feeding behavior is irregular, and below 7°C octopuses do not feed.
4. Culture management: The cage culture method is suitable for large-scale culture. The survival rate of seedlings caught by traps after 2 months of culture is 70-80%, and the survival rate of seedlings caught by angling is about 50%. When seedlings are stocked in cages, the mortality rate reaches 20-30% in 15 days, and then the mortality rate gradually decreases. After 15 days of culture, octopuses are divided into three sizes, large, medium, and small, and raised separately in different cages. In spring and autumn, the cages are cleaned once every 15 days, and in winter once every 30 days.