2.5.5. Vitamin C deficiency
* Signs:
Shrimp lacking of vitamin C usually has the following signs:
- Black areas appear in shrimp body, under shell, on the back of abdomen. In swimming legs and walking legs, there are black streaks.
- Shrimp eats less or skips meals, grows slowly, reduces resistance, and is vulnerable to opportunistic pathogens. 1-5% of the total shrimp die in pond daily (the total loss ratio is very high, 80-90%). Shrimp resistance to shocks is poor.
- Vitamin C deficiency is common in intensive farming ponds, especially in underdeveloped ponds with algae.
* Cause of disease:
There is a lack of vitamin C in shrimp diet.
* Preventions - treatments:
Use medicines and therapeutic measures as follows:
- Adding an appropriate amount of vitamin C in shrimp diet until the disease is cured.
- Provide shrimp feed with vitamin C regularly. Use industrial feed. Keep ponds without too much algae.
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, published on January 6th, 2015 of the Vietnam Directorate of Fisheries.
Viet Linh 2015. Translated by Lynn V.
