The method of eradicating crystal rotifers in the early stage of indoor seedling cultivation of Chinese anchovy

Abstract

The invention discloses an asplanchna eliminating method for early-stage indoor Yangtze river coilia ectenes seedling culture. The method is characterized in that during early-stage culture of coilia ectenes seedlings which are 12-18 days old, when asplanchna multiple rapidly and grow, salt is increased step by step until the salinity reaches 5, after the salinity reaches 5 through salt increasing, stabilization is conducted for 48 hours, during salinity stabilization, brackish water with the salinity of 5 is adopted for water changing, and asplanchna which sink to the bottom are eliminated in time; during asplanchna elimination through salt increasing, feeding with brachionus angularis and brachionus calyciflorus is stopped, and switching is conducted with brachionus urceus which are salvaged and collected with a bolting-silk net of 150 meshes and filtered with a bolting-silk net of 80 meshes; after 95% of the asplanchna sink to the bottom, salt is decreased step by step, pure water is adopted as salt decreasing water, and in the salt decreasing process, bottom suction is conducted once in the morning and afternoon respectively everyday to further eliminate the sunken asplanchna thoroughly; two days after step-by-step salt decreasing, the salinity of water in a seedling culture pond drops to 2 or below, and all original operations of seedling culture are restored.

Description

technical field [0001] The invention relates to a method for artificial breeding of the anchovy of the Yangtze River, in particular to a method for removing crystal rotifers in the early stage of indoor seedling cultivation of the anchovy of the Yangtze River. Background technique [0002] Coilia nasus Schlegel, also known as Coilia nasus Schlegel, commonly known as swordfish, is a migratory fish in rivers and seas. It is mainly distributed in the Yellow Sea, Bohai Sea and East China Sea in my country. It is distributed in all rivers leading to the sea, and the output of the lower reaches of the Yangtze River is the highest. Anchovy from the Yangtze River is famous for its tender meat, fresh and fat, and strong seasonality. It is also called "three delicacies of the Yangtze River" together with Yangtze River shad and puffer fish. In recent years, due to the influence of many factors such as overfishing and the deterioration of the ecological environment, the resources of the...

AI Technical Summary

Problems solved by technology

[0003] At present, the mainstream mode of artificial breeding of scorpion anchovy is the full artificial breeding mode in indoor cement pools. Artificial breeding is completely carried out under artificial control conditions. The rotifers live by feeding on small rotifers, and they have the characteristics of large food intake, fast growth, and strong fecundity. It is easy to form a dominant population in the seedling cultivation pool, making it difficult to maintain the number of small rotifers in the water body, resulting in the Fish fry cannot eat small rotifers that are suitable for eating, which eventually leads to problems such as slow growth, uneven specifications, and low survival rate of cuttlefish seedlings; in addition, the large number of growth of crystal rotifers puts management pressure on the water quality environment for seedling cultivation