Summary of the Characteristics of Aquatic Disease Outbreaks in Autumn and Winter
Autumn and Winter Aquatic Disease Summary
I. Summary of Disease Outbreaks in October
According to analysis of the aquatic aquaculture disease monitoring data for our province, although the disease situation among monitored cultured species in our province in October was generally somewhat alleviated, the affected area, incidence rate and mortality rate of white spot disease, Taura syndrome and red leg disease in shrimp and of undiagnosed-cause disease in abalone seedlings rose markedly, while the incidence rate and mortality rate of white spot disease in juvenile soft-shelled turtles, hemorrhagic disease in mud carp, and ciliate disease in mandarin fish rose slightly. The incidence rate and mortality rate of yellow croaker, grouper and red snapper continued to decrease; the incidence rate and mortality rate of hemorrhagic disease and red skin disease in grass carp, and of gill rot disease and enteritis disease in grass carp, sea bass, eel, tilapia and long-snouted catfish, of cataract disease in American bullfrog, of outbreak disease in crucian carp, and of dactylogyrus disease and ciliate disease in eel all declined; the disease situation in giant freshwater prawn and soft-shelled turtle was somewhat alleviated compared with last month. The mortality rate of undiagnosed-cause disease in industrially farmed adult abalone declined slightly compared with last month, and no diseases were still reported in cage-farmed abalone. The sporozoan disease in mud carp and tumor disease in grouper that occurred last month were not reported this month. Diseases newly reported this month include cryptocaryon disease in grouper and fish louse disease in red snapper. A newly added monitoring species is crocodile, and rot skin perforation disease was reported this month.
II. Analysis and Forecast of Disease Outbreaks in November-December
November-December is the period when air and water temperatures in our province are relatively low, and the temperature difference between day and night is still relatively large. It is predicted that the disease situation in marine and freshwater aquaculture aquatic animals will continue to be alleviated, and this is the period with the lowest incidence rate of the year. The incidence rate and mortality rate of enteritis disease, gill rot disease and outbreak disease in freshwater cultured species, red skin disease in grass carp, cataract disease in American bullfrog, rot skin perforation disease in crocodile, ulcer disease and undiagnosed-cause disease in sea bass, and dactylogyrus disease in mandarin fish and eel will continue to decrease, but the incidence rate of saprolegniasis will rise, and the incidence rate of ciliate disease will remain relatively high. In marine aquaculture, ulcer disease in grouper, enteritis disease in yellow croaker, and bacterial diseases in industrially farmed adult abalone may decrease, while the incidence rate and mortality rate of white spot disease and Taura syndrome in shrimp will remain relatively high. For warm-keeping culture of giant freshwater prawn, soft-shelled turtle, American bullfrog, etc., attention should be paid to regulating water quality and carrying out disease prevention measures.
III. Recommended Preventive Measures
1. Control methods for fish louse disease: (1) Disinfect the fish pond with 100 kg of quicklime per mu to kill adult fish lice, larvae and eggs. (2) Before stocking fry into the pond, soak the fish in a 1:100,000 to 1:50,000 potassium permanganate solution for 0.5-1 hour, which can kill larvae and some adults; (3) Splash 90% crystal trichlorfon over the whole pond at 0.5 g per cubic meter of water once a week for 3-4 consecutive treatments to kill larvae (use with caution on trichlorfon-sensitive fish such as mandarin fish, California sea bass and freshwater pomfret); (4) Tie branches and leaves of 4-5 trumpet-shaped stems into bundles and place 10 bundles per mu, which has a certain control effect.
2. Control methods for saprolegniasis: (1) Thoroughly disinfect the fish pond with chlorine preparations before stocking; (2) During catching, handling and stocking operations, do not injure the fish body, and the stocking density should be appropriate; (3) Use 2.5-5 kg of acorus juice and 0.5-1 kg of table salt per mu of water surface, add 2-20 kg of human urine, and splash over the whole pond, or splash over the whole pond a solution of table salt and baking soda combined at four ten-thousandths each, which has a certain therapeutic effect.
According to analysis of the aquatic aquaculture disease monitoring data for our province, although the disease situation among monitored cultured species in our province in October was generally somewhat alleviated, the affected area, incidence rate and mortality rate of white spot disease, Taura syndrome and red leg disease in shrimp and of undiagnosed-cause disease in abalone seedlings rose markedly, while the incidence rate and mortality rate of white spot disease in juvenile soft-shelled turtles, hemorrhagic disease in mud carp, and ciliate disease in mandarin fish rose slightly. The incidence rate and mortality rate of yellow croaker, grouper and red snapper continued to decrease; the incidence rate and mortality rate of hemorrhagic disease and red skin disease in grass carp, and of gill rot disease and enteritis disease in grass carp, sea bass, eel, tilapia and long-snouted catfish, of cataract disease in American bullfrog, of outbreak disease in crucian carp, and of dactylogyrus disease and ciliate disease in eel all declined; the disease situation in giant freshwater prawn and soft-shelled turtle was somewhat alleviated compared with last month. The mortality rate of undiagnosed-cause disease in industrially farmed adult abalone declined slightly compared with last month, and no diseases were still reported in cage-farmed abalone. The sporozoan disease in mud carp and tumor disease in grouper that occurred last month were not reported this month. Diseases newly reported this month include cryptocaryon disease in grouper and fish louse disease in red snapper. A newly added monitoring species is crocodile, and rot skin perforation disease was reported this month.
II. Analysis and Forecast of Disease Outbreaks in November-December
November-December is the period when air and water temperatures in our province are relatively low, and the temperature difference between day and night is still relatively large. It is predicted that the disease situation in marine and freshwater aquaculture aquatic animals will continue to be alleviated, and this is the period with the lowest incidence rate of the year. The incidence rate and mortality rate of enteritis disease, gill rot disease and outbreak disease in freshwater cultured species, red skin disease in grass carp, cataract disease in American bullfrog, rot skin perforation disease in crocodile, ulcer disease and undiagnosed-cause disease in sea bass, and dactylogyrus disease in mandarin fish and eel will continue to decrease, but the incidence rate of saprolegniasis will rise, and the incidence rate of ciliate disease will remain relatively high. In marine aquaculture, ulcer disease in grouper, enteritis disease in yellow croaker, and bacterial diseases in industrially farmed adult abalone may decrease, while the incidence rate and mortality rate of white spot disease and Taura syndrome in shrimp will remain relatively high. For warm-keeping culture of giant freshwater prawn, soft-shelled turtle, American bullfrog, etc., attention should be paid to regulating water quality and carrying out disease prevention measures.
III. Recommended Preventive Measures
1. Control methods for fish louse disease: (1) Disinfect the fish pond with 100 kg of quicklime per mu to kill adult fish lice, larvae and eggs. (2) Before stocking fry into the pond, soak the fish in a 1:100,000 to 1:50,000 potassium permanganate solution for 0.5-1 hour, which can kill larvae and some adults; (3) Splash 90% crystal trichlorfon over the whole pond at 0.5 g per cubic meter of water once a week for 3-4 consecutive treatments to kill larvae (use with caution on trichlorfon-sensitive fish such as mandarin fish, California sea bass and freshwater pomfret); (4) Tie branches and leaves of 4-5 trumpet-shaped stems into bundles and place 10 bundles per mu, which has a certain control effect.
2. Control methods for saprolegniasis: (1) Thoroughly disinfect the fish pond with chlorine preparations before stocking; (2) During catching, handling and stocking operations, do not injure the fish body, and the stocking density should be appropriate; (3) Use 2.5-5 kg of acorus juice and 0.5-1 kg of table salt per mu of water surface, add 2-20 kg of human urine, and splash over the whole pond, or splash over the whole pond a solution of table salt and baking soda combined at four ten-thousandths each, which has a certain therapeutic effect.