Slow growth of vannamei shrimp is often an issue faced by shrimp farmers. Various factors can cause slow growth in vannamei shrimp, one of which is water quality. Thus, it is important for shrimp farmers to measure and monitor the physical water parameters in their ponds. What is the relationship between physical water parameters and shrimp growth? Learn more about it in this article!
The Relationship between Physical Water Parameters and Shrimp Growth
Among many water parameters that can be measured in ponds, the four most important physical water parameters that have the biggest impact on shrimp growth and survival rate (SR) are temperature, pH, DO, and salinity.
1. Temperature
Temperature affects shrimp growth as it affects the speed of biochemical reactions. The recommended temperature for vannamei shrimp to grow is 28-32°C. If the temperature is too low, shrimp metabolism and appetite will decrease.
Read more: The Most Effective Feeding Practices for Vannamei Shrimp
2. pH
pH also needs to be maintained within a safe range to avoid affecting shrimp's metabolism and physiological condition. The recommended pH range for shrimp ponds is 7.8-8.5. A pH that is too low can cause slow growth and decreased appetite. Shrimp also become more prone to stress and disease.
3. DO
Dissolved oxygen (DO) in the farm should be at an ideal range of not less than 4 ppm. DO plays an important role in shrimp respiration and is affected by weather, paddlewheels, and plankton population. If the DO is below 4 ppm, shrimp growth can slow down due to decreased appetite.
4. Salinity
The ideal salinity for vannamei shrimp is 15-30 ppt. However, vannamei shrimp can adapt to a fairly wide range of salinity. Low salinity can reduce oxygen, cause plankton death, and affect the shrimp molting process.
The Role of MBW in Shrimp Growth
MBW is the Mean Body Weight of shrimp, and can be used interchangeably with the term ABW ABW or Average Body Weight. The formula for MBW is:
For example, Mr. Jali found that the total net weight of his shrimp was 200 grams with a total stock of 100 shrimp. He calculated the ABW/MBW of his shrimp in the following way:
ABW/MBW = shrimp net weight (grams) / number of shrimp (shrimp) ABW/MBW = 200 grams / 100 shrimp ABW/MBW = 2 grams/shrimp.
Case Example of Slow Vannamei Shrimp Growth
For example, if the MBW of shrimp from the sampling data over several consecutive weeks increases only slightly, or does not increase, shrimp farmers should also check the physical water parameters. Suppose the parameters are found to be lower than the ideal range, as in the following case:
Temperature: 25°C pH: 7.0 DO: 2 ppm Salinity: 12 ppt
Additionally, if vannamei shrimp growth is slow, the color of the pond water should also be observed. The ideal color for vannamei shrimp growth is brownish green, as it indicates that the levels of phytoplankton and zooplankton in the pond are stable and can support shrimp growth by providing natural feed and being a buffer for sunlight intensity. If the water color is not ideal, necessary adjustments need to be made.
Read more: How to Make Pond Water Brownish Green
Conclusion
To ensure that shrimp growth occurs at the normal range in order to achieve cultivation targets, water quality parameters need to be monitored, especially physical water quality. By having a thorough record of shrimp MBW and water quality, farmers can detect slow shrimp growth and select the proper treatment to be done in order to make adjustments.
To record and monitor farm conditions more conveniently, farmers can use JALA App. JALA App is a shrimp farm management application that is #HeretoHelp you better understand farm performance and reach cultivation targets. Start cultivating more productively and efficiently with JALA App!
