How to prevent and control diseases in artificial breeding of scallop

During the artificial breeding period, scallop larvae are easily infected with bacteria and fungi, causing a large number of deaths.

Bacterial diseases are common Vibrio, Vibrio anguillaris a specialized decomposition of organisms, in a very short period of time so that the larval face plate decomposition, this condition especially in the 5-7 days after egg collection, spread very fast, 6-8 hours can kill all larvae. At present, once the disease caused by this pathogenic bacterium is discovered, there is no treatment plan, and it can only be prevented. Prevention methods: strengthen the physique of parent shellfish during fattening, pour the pool every day for fattening, thoroughly eliminate bacterial pathogens, pour the pool frequently during larva cultivation (pour the pool once every 3 days), use potassium permanganate after pouring the pool, disinfect and clean the bottom of the pool.

Pseudomonas belongs to Aeromonas. These bacteria are usually found in seawater, sediment, bottom pollutants, animal body surface or digestive tract. Once conditions are suitable, they will multiply in large quantities and invade scallop larvae or juvenile shellfish tissues to become pathogenic bacteria. Infected larvae sink to the bottom of the pool, face plate cilia shortage uneven, reduced mobility, and soon a large number of deaths. Ulcer and even decomposition were found in larval tissues under microscope. The treatment effect of this disease is not significant, prevention methods: remove metabolites and bait residue at the bottom of the cultivation pool to prevent bacterial reproduction.

In larval cultivation, there is often a mold and fungus infection of the larva foot muscle part, this disease is often found after the larva shell length of 168 microns, the infection is slow, it is clear under the microscope that the larva growth and development of the shell length, shell height growth, internal organs are also normal development, but the foot muscle, especially the foot part began to fester, lose crawling function, in the late stage of the eyepoint larva, the probability is high, the face plate began to atrophy and degenerate, and foot muscle fester, so that the larva sinks and dies.

At present, there is no good way to treat bacteria in seawater. Preventive measures are mainly taken. The bottom of the pool is often cleaned thoroughly, disinfected, and frequently poured into the pool. In addition, the most effective way is to disinfect seawater with ultraviolet rays.