Prevention and treatment of stomach rot in sea cucumber culture

The disease mostly occurs in the late stage of big ear larvae, and it is more likely to occur during the high temperature period from June to July every year and when the larval culture density is high. The disease has been found in Shandong and Liaoning provinces, and the incidence is increasing year by year. The main symptoms of death are as follows: the gastric wall of the larva is thickened and rough, the peripheral boundaries of the stomach become blurred, then atrophy, deformation, serious erosion of the whole gastric wall, which can eventually lead to the death of the larva. The feeding ability of the diseased larvae decreased or did not feed, the growth was retarded, the shape and size was uneven, and the metamorphosis rate from auriculate larvae to bottle larvae was low.

On the one hand, the cause of the disease is due to poor food quality, such as feeding aging, precipitation and deterioration of single-celled algae bait, or single feed nutrition, such as feeding gold algae, flat algae and other bait alone. On the other hand, some bacteria infect larvae can also cause the disease. At present, 2 strains of pathogenic bacteria have been isolated, and their classification and identification are under way.

There are two main control measures: on the one hand, feeding fresh and palatable bait such as Chaetoceros, Dunaliella Salina or marine yeast to meet the needs of larval development and growth; on the other hand, appropriately increasing the amount of water exchange and reducing the number of bacteria in water. The use of furan antibiotics 3 × 10-6 5 × 10 6 medicine bath has a good effect.