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Dietary lipid requirement of whiteleg shrimp Litopenaeus vannamei juveniles cultured in biofloc system
(Wiley, 2020-06)
An eight-week feeding trial was conducted to evaluate the contribution of biofloc on dietary lipid requirement in whiteleg shrimp Litopenaeus vannamei. Five diets with graded levels of dietary lipid (45, 60, 90, 120 and ...
Biofloc-based nursery production system: Heeding the call towards a sustainable shrimp culture industry in the Philippines
(International Network for Natural Sciences, 2022)
The increasing global population resulted in intense pressure on the food production sectors to meet the rise in food demand. The aquaculture industry, which is one of the major food production sectors, provides opportunities ...
Vibrio load and percentage composition of sucrose‐fermenting vibrios in Nile tilapia (Oreochromis niloticus) cultured in brackish water earthen ponds and biocontrol potential of recycled tilapia‐conditioned greenwater against population growth of V. parahaemolyticus and non‐sucrose‐fermenting vibrios in the grow‐out culture of white leg shrimp (Litopenaeus vannamei)
(Wiley, 2022-10-20)
<i>Vibrio</i> are known opportunistic pathogens of pond-cultured fish and shrimp. This study determined the presumptive <i>Vibrio</i> count (PVC) and percentage composition of “beneficial” sucrose-fermenting vibrios (SFVs) ...
Lime application to condition soil to pH 11 controls growth of harmful vibrios and WSSV
(European Association of Fish Pathologists, 2023-05-26)
Shrimp farming has been devastated by several diseases. Disease outbreaks can be prevented by optimising environmental conditions or by eliminating risks factors including carrier organisms. These can be achieved through proper pond preparation. One important step in pond preparation is the application of hydrated lime.
This paper describes the effect of hydrated lime application to condition pond soil to pH 11 on the pond ecosystem, more specifically on soil pH and biota. The experiment was done using three 600 m<sup>2</sup> brackish water ponds. After hydrated lime application, the wet soil pH on the 1<sup>st</sup>-8<sup>th</sup> day was significantly higher (P<0.05) compared to the pH before liming to pH 11, and flushing after flooding for 24 h. Soil pH of 11 was observed 24-48h after lime application. Moreover, unwanted species like crabs and fish were found dead. Liming to pH 11 negatively affects the counts of green vibrio colonies thereby decreasing the percentage of green vibrios (PGV). In another experiment, three 750m<sup>2</sup> earthen ponds were used. The pond soils were previously positive for the Whitespot Syndrome Virus (WSSV), hydrated lime were applied to bring the pond soil pH to 11. After lime application, WSSV was not detected in the pond soils.
Results showed that increasing the soil pH to ≥11 positively affects the pond ecosystem. Liming encourages the proliferation of yellow vibrios and the eradication of carrier species (i.e. crabs) as well as predators (i.e. fish) in the ponds. Furthermore, liming to pH 11 may also eradicate White spot virus from the pond sediment. To implement a 1-unit increase in wet pH, hydrated lime should be applied at 2T/ha....