2.5.1. Diseases caused by vibrio bacteria
* The signs:
- Broken antenna, black gill, tail rot, or black spots occur.
- Shrimp is dirty and weak; has dirty gill; the body converts into red pink; stop eating and die.
- Shrimp deaths can occur when the diseases are in acute phases. If it happens chronically, shrimp can grow slowly, have soft shell and separate with their groups.
- The main agents causing the diseases are bacteria of the genus Vibrio.
- Vibrio bacteria enter farming ponds by water, breed, and feed from the bottoms if cleaning work is not effective enough.
* Preventions - treatments:
- Apply synthetic methods to inhibit the growth of bacteria:
+ Keep good water quality in ponds.
+ Shrimp density is not too high.
+ Avoid vulnerable factors to shrimp.
+ Recurring use of microbial products to reduce the amount of organic matters in ponds.
+ Reducing salinity down to 15-20 per thousand may restrict the development of Vibrio bacteria.
+ Increase resistance with good environmental management and vitamins C, A, E.
- The diseases often occur when water in ponds is dirty; shrimp is weak. Apply simultaneously these solutions:
+ Improve environmental conditions and kill bacteria in shrimp body: siphon bottoms of the ponds; change new water to reduce density of bacteria in water; use products permitted in the list of the Ministry of Agriculture and Rural Development and base on the manufacturers' instructions.
+ Increase resistance for shrimp with vitamin C in feed.
+ Use squid oil combined with feed: 5-10ml/kg of feed.
+ Stimulate molting by Saponine 10-15g/m3.
Source: Temporary process for safe brackish-water shrimp farming in areas affected by diseases in Vietnam. According to The Official Dispatch No. 10/TCTS-NTTS. January 6th, 2015. Vietnamese Directorate of Fisheries
Viet Linh © 2015. Translated by Sonia Linh V.
In rainy season
In the shrimp ponds
Temporary process for safe brackish-water shrimp farming in areas affected by diseases in Vietnam