The effect of several types of mangrove exctracs on tiger shrimp Penaeus monodon survival rate challenged with White Spot Syndrome Virus (WSSV)

Abstract

This experiment was aimed to determine the survival rate of tiger shrimp on the use of several types of mangrove extracts challenged with the White Spot Syndrome Virus (WSSV). The experiment was conducted in November 2015 at the Research Institute for brackish water Aquaculture and Fisheries Extension (RIBAFE), Maros. The plastic container of 40 L volume was filled with 30 L of seawater at a salinity of 28 ppt which had been disinfected with chlorine powder of 150 ppm and neutralized with Sodium Thiosufateof 75 ppm, stocked with 10 ind of tiger shrimps with the size of 5-7 g/pcs. The challenge test of mangrove extract with WSSV was done by mixing 5 μL of WSSV suspension with 10 μL of mangrove extract solution (500 mg/100 mL of NTE buffer). The mixing solution was then incubated at 29 oC for 3 hours and then infected to tiger shrimp by intramuscular injection. The experimental design used was Completely Randomized Design with treatments; A). butanol extract of Sonneratia alba; B). butanol extract of Sonneratia caseolaris; C). butanol extract of Sonneratia lanceolata; D). butanol extract of Bruguiera gymnorrhiza; E). diethyl ether extract of S. alba; F). diethyl ether extract of Bruguiera gymnorrhiza; G). Control (shrimps injected with WSSV suspension without mangrove extract. Each treatment was repeated 3 (three) times and tiger shrimp were reared for 10 days. Observations of tiger shrimp mortality were performed daily, while Total Hemocyte Count (THC), Differential Hemocyte Count (DHC), ProPO values and WSSV infection were observed at the end of the study. Analysis of variance, which was followed by Least Significant Difference test were conducted on the survival rate of tiger shrimp. The results showed that over 50% of tiger shrimp relative survival was obtained by the treatment that used butanol extract of S.alba, butanol extract of S.caseolaris, butanol extract of B. gymnorrhiza, and diethyl ether extract of S. alba. These experiments showed that the four extracts of mangrove effectively increased the survival of tiger shrimp. The highest average survival rate of tiger shrimp was obtained by the treatment that used diethyl ether extract of S. alba, while the lowest was found in the positive control, and both treatments were significantly different (P <0.05).The result indicated that diethyl ether extract of S. alba was found to be the most potential extract to control WSSV disease in tiger shrimp.