Integration of finfish in shrimp (Penaeus monodon) culture: an effective disease prevention strategy

A farm trial on integration of finfish (i.e., tilapia) in shrimp (Penaeus monodon) culture was conducted in Negros Occidental, Philippines to prevent luminous vibriosis in shrimp. The farm engaged in shrimp monoculture from 1987 to 1995. However, the prevailing luminous vibriosis outbreaks that started in 1994 prompted the farm operator to shift to tilapia culture in 1995-1996. The farm resumed shrimp operations in 1996 but by this time tilapia had already been integrated in the culture system. This paper reports on the results of the trial for 1999 using three ponds (ponds 7, 9, 29). These ponds had previously been used for tilapia culture for two years. During shrimp culture, they drew water from reservoirs stocked with tilapia and within the shrimp ponds tilapia are also stocked inside cages. This technology integrates crop rotation, biological pretreatment and polyculture into one system. During the culture period the chemical and bacteriological quality of soil, water and shrimp were monitored. Water quality parameters were within normal ranges for shrimp culture. Luminous bacterial counts in water and shrimp were consistently below 10 colony forming units (cfu)/ml and 103 cfu/hepatopancreas (hp), respectively. These levels are below threshold levels associated with luminous vibriosis outbreaks. With a stocking density of 19.43 shrimp postlarvae (PL)/m2, pond 7 yielded 2,605 kg shrimp/ha with an estimated survival of 35.65% after 109 days of culture (DOC). With a stocking density of 18.69 PL/ m2, pond 9 yielded 5,472 kg shrimp/ha with survival of 100% after 148 DOC. With a stocking density of 19.33 PL/m2, Pond 29 yielded 5,702 kg shrimp/ha with survival of 82.66% after 151 DOC. The relatively low production in pond 7 can be attributed to the inferior quality of the batch of stocked shrimp PL that already had a low survival of 50% at DOC 30. Comparing the production performance from this present trial with that of this and other farms before the 1994 outbreaks, these good results cannot simply be attributed to chance despite of the lack of control in this farm trial. These results are consistent with the results of a previous trial of the same farm, the ongoing verification trials in Negros Occidental, and the observations of many farmers in other parts of the country on the potential of shrimp-finfish integration in preventing luminous vibriosis in shrimp

Vibrio harveyi and the 'green water culture' of Penaeus monodon

The 'green water culture' of the tiger shrimp, Penaeus monodon, is an innovative culture technique for the grow-out rearing of shrimps. This culture method involves the use of rearing water of tilapia for the rearing of tiger shrimp in grow-out ponds and on the polyculture of shrimp with tilapia. This culture technique was reported to present disease outbreaks attributed to luminescent Vibrio. To understand the possible mechanisms of luminous Vibrio control in the green water culture system several studies were conducted. This review summarizes the highlights obtained so far from these studies consisting of a) effect of rearing waters from tilapia culture and shrimp cultured with tilapia on Vibrio harveyi; b) estimation and preliminary identification of cultivable bacteria, fungi and phytoplankton flora associated with the 'green water culture' system and c) detection of anti-Vibrio harveyi metabolites from bacteria, yeast, filamentous fungi and phytoplankton indigenous to the 'green water culture' system

Phytochemical composition antioxidant and antibacterial activity of the Philippine marine green alga (Ulva pertusa)

The phytochemical constituents, total phenolic and flavonoid contents, antioxidant and antimicrobial activities of the ethanolic extract of the marine green alga Ulva pertusa collected from floating fish net cages off the coast of Guimaras island, Philippines, were investigated. Qualitative phytochemical analysis revealed the presence of bioactive compounds including alkaloids, flavonoids, phenols, saponins, tannins, and terpenoids. Quantitatively, total phenolic and flavonoid contents of the extract were 20.54±2.08 mg gallic acid equivalent (GAE) g-1 and 539.07±6.36 mg rutin equivalent (RE) g-1, respectively. The antioxidant activity of the extract using 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay exhibited a concentration-dependent radical scavenging capacity. Additionally, the ethanolic extract inhibited the growth of Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Streptococcus agalactiae, Aeromonas hydrophila, A. sobria, and Vibrio harveyi in a concentration-dependent manner with strong inhibitory activity at 100 mg mL-1 concentration. Taken together, U. pertusa contains bioactive compounds that possess potent antibacterial activity and remarkable antioxidant capacities. These substances are promising candidates that may be utilized in the synthesis of novel drugs.This study was funded by the Government of Japan Trust Fund V through the Regional Disease Project (study code: FH01-F2010-T) and partly by SEAFDEC AQD

Draft genome sequence of multidrug-resistant Vibrio parahaemolyticus strain PH698, infecting penaeid shrimp in the Philippines

The emergence of multidrug-resistant bacterial strains in diverse settings has been reported globally. In the Philippine shrimp aquaculture industry, antibiotics are used for the treatment of bacterial diseases during the production cycle. We report the draft genome of Vibrio parahaemolyticus PH698, a multidrug-resistant strain isolated from a Philippine shrimp farm

Acute hepatopancreatic necrosis disease (AHPND) outbreaks in Penaeus vannamei and P. monodon cultured in the Philippines

Acute hepatopancreatic necrosis disease (AHPND) has recently emerged as a serious disease of cultured shrimp. It has also been described as early mortality syndrome (EMS) due to mass mortalities occurring within 20 to 30 d after stocking of ponds with postlarvae. Here, Penaeus vannamei and Penaeus monodon from shrimp farms in the Philippines were examined for the toxin-producing strain of Vibrio parahaemolyticus due to AHPND-like symptoms occurring in marketable size shrimp. In the P. vannamei, histology revealed typical AHPND pathology, such as sloughing of undifferentiated cells in the hepatopancreatic tubule epithelium. Analysis using the IQ2000 AHPND/EMS Toxin 1 PCR test generated 218 bp and 432 bp amplicons confirmative of the toxin-producing strain of V. parahaemolyticus among shrimp sampled from 8 of 9 ponds. In the P. monodon, histology revealed massive sloughing of undifferentiated cells of the hepatopancreatic tubule epithelium in the absence of basophilic bacterial cells. PCR testing generated the 2 amplicons confirmatory for AHPND among shrimp sampled from 5 of 7 ponds. This study confirms the presence of AHPND in P. vannamei and P. monodon farmed in the Philippines and suggests that the disease can also impact late-stage juvenile shrimp.We are very grateful to DOST-PCAARRD and SEAFDEC/AQD for funding this work and to the Shrimp Pathogenomics team, especially Dr. N. R. L. Rojas and Dr. E. P. Enriquez. We thank the shrimp farms that provided the samples and the staff of Fish Health Section Diagnostic Services and Microtechnique Lab for the technical support. We also thank T. W. Flegel for confirming our histological analysis and for assistance in editing the manuscript

Mortality of pond-cultured Litopenaeus vannamei associated with acute hepatopancreatic necrosis disease (AHPND) and white spot syndrome virus (WSSV) infection in the Philippines

Mortalities of up to 60% were observed in pond-cultured Litopenaeus vannamei in Bohol, Philippines. Histopathological examination revealed typical acute hepatopancreatic necrosis disease (AHPND) pathology. PCR test generated 1,269 bp and 230 bp amplicons confirmative for the toxin-producing AHPND strain of Vibrio parahaemolyticus among shrimp sampled from eight ponds. The same samples were subjected to PCR analyses for the presence of other viruses, namely WSSV, IHHNV, IMNV, and TSV. The samples were negative for the viruses except WSSV, which was detected after one-step PCR in six out of eight ponds. These results suggested that shrimp were infected dually with AHPND V. parahaemolyticus and WSSV