Proceedings of the SEAFDEC-OIE Seminar-Workshop on Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines

This seminar/workshop was held at the Conference Room of Sarabia Manor Hotel in Iloilo City, Philippines on 4-6 December 2001. It was co-organized by the Southeast Asian Fisheries Development Center (SEAFDEC) and the Office International des Epizooties (OIE). The meeting was financially supported by the Government of Japan (GOJ) Trust Fund through the Regional Fish Disease Project. The objectives of the seminar/workshop were to (1) review the current research studies and diagnostic techniques on viral diseases of shrimp and marine fish in Southeast Asia; (2) review the current research studies on techniques in controlling shrimp vibriosis and give advice for on-going research studies of the project; and (3) identify an appropriate training program for the project. In total, 55 participants attended the meeting coming from the Unites States (1), Norway (1), OIE (2), the Network of Aquaculture Centres in Asia-Pacific (NACA, 1), the SEAFDEC Secretariat (1) and nine SEAFDEC member countries (2 from Brunei Darussalam; 1 from Cambodia; 1 from Indonesia; 8 from Japan; 1 from Myanmar; 30 from the Philippines; 1 from Singapore; 5 from Thailand; 1 from Vietnam).

Recent Submissions

  • Conference paper

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

    JO Paclibare, RC Usero, JR Somga & RN Visitacion - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    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.
  • Conference paper

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

    GD Lio-Po, EM Leaño, RC Usero & NG,J Guanzon - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    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.
  • Conference paper

    Diagnostic practices for marine fish viral diseases in Thailand 

    S Kanchanakhan - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The Department of Fisheries, Thailand has three institutions that are capable of virus isolation using fish cell culture system: the Aquatic Animal Health Research Institute (AAHRI), the National Institute of Coastal Aquaculture (NICA) and the Marine Shrimp Research and Development Center (MSRDC). The AAHRI is located in Bangkok while the others are in Songkhla province, south of Bangkok. Fish cell culture system was initiated in AAHRI and NICA in 1992-1993. Both institutions spent 6-12 months to develop and practice cell culture. Since then, fish cell lines have been utilized for virus isolation. Various rhabdoviruses, iridoviruses and reoviruses were isolated from diseased freshwater fishes as well as iridoviruses from cultured frog. In addition, iridoviruses and nodavirus were also isolated from diseased marine finfish. The AAHRI maintains 8 fish cell lines and 2 reptile cell lines while NICA maintains 3 fish cell lines. The MSRDC has 5 marine finfish cell lines. In the three institutions, Leibovitz -15 is the general culture medium used in both tissue culture flask and tissue culture plate systems. This medium is capable of maintaining the pH in close and open culture systems without CO2 incubation.

    Diagnostic practices for marine viral diseases in Thailand include virus isolation, histology and polymerase chain reaction (PCR) amplification technique. As diagnosis in virology is costly, only suspected virus-infected specimens submitted to the Aquatic Animal Disease Clinics are examined for viruses. An active surveillance program of marine viral diseases, with support from the Government of Japan-Trust Fund, has begun this year. The diagnostic procedures for marine viral diseases in the three institutions are similar to the techniques described in the Office International des Epizooties (OIE) Diagnostic Manual and Blue Book.
  • Conference paper

    An overview of PCR techniques for shrimp disease diagnosis in Asia, with emphasis on Thailand 

    TW Flegel - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Asia leads the world in cultivated shrimp production with export earnings in the order of billions of US dollars per year. In spite of this success, annual production decreased in the late nineties because of widespread epizootics caused by new viral pathogens. Although, these viruses were no cause for alarm to human health authorities, they were economically crippling for Asian shrimp farmers. In Thailand, shrimp production trends have mirrored those in the rest of Asia, except that recovery from the viral epizootics has been somewhat better than it has for most of its close neighbors. Our work in Thailand has focused on the characterization of the causative viruses and on the development of rapid diagnostic probes for them. Similar work has been done elsewhere. The aim of the work has been to develop effective control measures to help shrimp farmers. We are engaged in similar work on bacteria and parasites. The major viruses of concern (in our estimated order of economic impact for Thailand) are white-spot syndrome virus (WSSV), yellow-head virus (YHV), hepatopancreatic parvovirus (HPV), monodon baculovirus (MBV) and infectious hypodermal and haematopoeitic virus (IHHNV). We have also prepared probes for Vibrio parahaemolyticus and for a microsporidian parasite, Agmasoma penaei. These highly specific and sensitive tools for detection are already helping shrimp farmers and we hope that new technological advances will make them practicable in the field. At the moment, however, the most rapid test is the polymerase chain reaction (PCR) test, which takes approximately 3 hours to complete. This review covers important Asian shrimp diseases for which PCR tests are currently available.
  • Conference paper

    Diagnostic and preventive practices for iridovirus in marine fish 

    K Nakajima - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The first outbreak of red sea bream iridoviral disease (RSIVD) caused by red sea bream iridovirus (RSIV) was recorded among cultured red sea bream (Pagrus major) in 1990 in Ehime, Shikoku, Japan. Since then, the disease has caused mass mortalities of many cultured marine fishes. From 1990-2000, RSIVD was detected in 31 cultured marine fish species, including 28 Perciformes, 2 Pleuronectiformes and 1 Teteraodontiformes, in 18 prefectures in the southwestern part of Japan. The infected fish are lethargic and show severe anemia, petechiae of the gills, and enlargement of the spleen. Histopathologically, the disease is characterized by the presence of enlarged cells in the spleen, heart, kidney, liver and gills that are deeply stained with Giemsa solution.

    Diagnostic methods for RSIV, such as the observation of stained imprints or tissue sections, an immunofluorescent (IF) test with a monoclonal antibody (MAb) and a polymerase chain reaction (PCR) technique have been developed. The IF test with MAb is commonly used in the rapid diagnosis of RSIV-infected fish. For an effective control measure against RSIVD, a formalin-killed vaccine has been developed and this showed a significant effect in red sea bream under both experimental and field conditions.
  • Conference paper

    Diagnostic and preventive practices for WSSV in Japan 

    K Mushiake - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    White spot syndrome (WSS), considered equivalent to PAV (penaeid acute viremia) in Japan, has become the most serious problem not only in the farming industry but also in hatcheries for sea ranching of kuruma prawn, Penaeus japonicus. The prevalence of WSSV (white spot syndrome virus), the causative agent of WSS, was examined in wild kuruma prawn broodstocks by nested PCR (polymerase chain reaction). As a result, WSSV was detected at the highest prevalence (10.1%) in the ovary of female prawn. This result indicates that spawners are sources of infection. In 1997, brooders were pre-screened using PCR to detect WSSV before these spawned. WSSV was noted to occur in postlarvae obtained from brooders caught between July and August. In 1998 and 1999, eggs were selected based on WSSV detection by PCR from receptaculum seminis of spawned broodstock. Consequently, WSSV did not occur in their offsprings in both years. These results strongly indicate that selection of eggs based on PCR results is a practical way of controlling WSSV in hatcheries.
  • Conference paper

    Probiotics in aquaculture 

    E Ringø - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The skin, lateral line, gills and gastrointestinal tract or a combination of these organs are suggested to be infection routes in fish. This presentation will present some information on pathogenesis, protection against bacterial adhesion, autochthonous microbiota in the gastrointestinal tract and prebiotics. This information is important when discussing the use of probiotics in aquaculture.

    Intensive fish production has increased the risk of infectious diseases and there is a growing need to find alternatives to antibiotic treatment for disease control as indiscriminate use of antibiotics in many parts of the aquaculture industry has led to the development of antibiotic resistance in bacteria. Today, a range of microorganisms have been suggested as or evaluated as fish probiotics. These include lactic acid bacteria, Bacillus species, Pseudomonas species, Vibrio species and other Gram-negatives. However, research in probiotics for aquaculture is at an early stage and much work is still needed.

    Another aspect on fish health is the use of prebiotics to increase the population level of already beneficial bacteria colonizing the gastrointestinal tract and the effect of diet in disease resistance.
  • Conference paper

    Recent Asian initiatives under the NACA regional programme on aquatic animal health management 

    MG Bondad-Reantaso - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The activities of NACA in support of improving aquatic animal health management within Asia dates back since 1986 when it was first involved in the UNDP/FAO/ODA (and subsequently DFID) sponsored program on Epizootic Ulcerative Syndrome (EUS). Consequently, in cooperation with relevant governments and institutions, NACA implemented a Regional Research Program on Ulcerative Syndrome in Fish and the Environment, from 1986 to 1989, which produced most of the scientific data on environmental parameters associated with EUS outbreaks in the Asia-Pacific region. Between 1989-1990, NACA and ADB implemented the Regional Study and Workshop on Fish Disease and Fish Health Management which revealed a scenario of environment-linked disease problems, product contamination, and environmental impacts on aquaculture, and for the first time losses suffered by Asian aquaculture from fish diseases were quantified. The study provided the first broad guidelines to regional and national strategies for developing capacities in fish health management. In 1991, OIE Tokyo approached NACA to initiate cooperation with respect to aquatic animal disease reporting which eventually led to an Expert Consultation on Aquatic Animal Disease Reporting in 1996. Between 1992 to 1996, NACA was involved in the following regional activities: (a) collaborating with IDRC and UPM in a Tropical Fish Health Management course, that ran for two intakes of students at UPM; (b) participating in the FAO 1994 Expert Consultation on Health Management held at UPM in Malaysia; and (c) the 1996 Consultation on Quarantine and Health Certification of FAO and AAHRI through the ODA-funded SEAADCP project. In l998, a joint publication - 'EUS Technical Handbook' with ACIAR, DFID, NSW Fisheries, AAHRI through SEAADCP and NACA - was completed.

    The major recommendations of the various regional meetings/consultations became the basis for the development of a strong multi-disciplinary Asia-Pacific regional programme on aquatic animal health management. At the request of Asian governments, NACA and FAO developed a Regional Technical Cooperation Programme on "Assistance for the Responsible Movement of Live Aquatic Animals" (FAO RTCP/RAS 6714 and 9605). The project was implemented from 1998 to 2001 in cooperation with 21 governments/territories in Asia-Pacific region, OIE FDC, OIE Tokyo, AFFA, AusAID/APEC and AAHRI.

    The programme and its outputs were developed through three years (1998 to 2001) of awareness raising and consensus building through various national and regional level activities (e.g. workshops, training courses, expert consultation, health assessments, etc.). This multidisciplinary Regional Aquatic Animal Health Management Programme has now been adopted by Asian governments (including NACA members and participating governments within ASEAN) as an important element of NACA's Third Five Year Work Programme (2001-2005). The current thrust of the programme is to assist countries in implementing the 'Technical Guidelines', giving special emphasis to the concept of "phased implementation based on national needs", including monitoring and evaluation of its implementation. One of the mechanisms to support Asian governments in the implementation of the 'Technical Guidelines' is through regional cooperation where effective partnership with relevant organizations will be continuously established and strengthened. Designated National Coordinators will continue to be the focal points for its implementation.

    A Regional Advisory Group on Aquatic Animal Health has been established which will function as an official regional expert group that will ensure the provision of expert advice to Asian governments in the implementation of the 'Technical Guidelines', with NACA providing institutional support and FAO and OIE providing technical guidance. The main elements for regional cooperation include: (a) Promoting effective cooperation through regional resource centers on aquatic animal health; (b) Harmonization of procedures for health certification, quarantine and diagnostics; (c) Support to capacity building; (d) Awareness raising, communication and information exchange on aquatic animal health; (e) Regional disease reporting; (f) Emergency response; and (g) Joint activities for risk reduction in shared watersheds.The paper also briefly include other health related projects jointly being developed and/ or currently carried out by NACA with other organizations (e.g. ACIAR, APEC, ASEAN, CSIRO, DANIDA, IDRC, MPEDA, MRC and SEAFDEC-AQD).
  • Conference paper

    Fish disease control project of SEAFDEC Aquaculture Department 

    Y Inui - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
  • Conference paper

    Diagnostic and preventive practices for viral nervous necrosis (VNN) 

    T Nakai - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Viral nervous necrosis (VNN) or viral encephalopathy and retinopathy (VER) caused by piscine nodaviruses (=betanodaviruses) has spread worldwide in the past decade among cultured marine fish. The present paper briefly describes procedures currently practiced in the diagnosis and prevention of the disease.
  • Conference paper

    Global aquatic disease control activities of OIE and the Fish Diseases Commission 

    B Hill - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
  • Conference publication | Book

    Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques: Proceedings of the SEAFDEC-OIE Seminar-Workshop on Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines 

    Y Inui & ER Cruz-Lacierda (Eds.) - 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The meeting aimed to: review the current research studies and diagnostic techniques on viral diseases of shrimp and marine fish in Southeast Asia; to identify an appropriate training program for fish disease project; and to review the current research on techniques in controlling shrimp and crab vibriosis. Every chapter in this volume is cited individually.
  • Conference paper

    Advances in diagnosis and management of shrimp virus diseases in the Americas 

    DV Lightner - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia - Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The most important diseases of cultured penaeid shrimp, in terms of economic impact, in Asia, the Indo-Pacific, and the Americas, have infectious etiologies. Although diseases with bacterial, fungal, and parasitic etiologies are also important, certain virus-caused diseases stand out as the most significant. The pandemics due to the penaeid viruses WSSV, TSV, YHV, and IHHNV have collectively cost the penaeid shrimp industry billions of dollars in lost crops, jobs, and export revenue. Although not as sudden nor as catastrophic in their onset and course, certain bacterial, fungal, and parasitic diseases of shrimp have also been responsible for very significant production losses, and the relative importance of many of these diseases should not be discounted.

    The social and economic impacts of the pandemics caused by WSSV and TSV have been especially profound in the Americas, and in the wake of these viral pandemics the shrimp culture industry has sought ways to restore the industry’s levels of production to the “pre-virus” years. Central to improving disease) prevention and management strategies is the incorporation of the concepts of biosecurity into shrimp farm design and operational strategies. Disease management in shrimp aquaculture is an important component to biosecurity of farms and to the sustainability of individual farms, shrimp farming countries, or entire geographic regions. The first step in disease management requires the availability of accurate and reliable diagnostic methods and knowledge of the biology of the diseases of concern. The recognition of the need for biosecurity and disease management in the Americas is reflected in the recent proliferation of shrimp disease diagnostic laboratories in the Americas. Where there were only a handful of shrimp disease diagnostic laboratories a decade ago, there are 40 or more such laboratories serving the industry today.

    Diagnostic methods may be applied to determining the cause of disease(s) that are adversely affecting the culture performance or survival of farmed shrimp stocks or they may be used for surveillance purposes to screen for the presence of specific pathogens in otherwise healthy shrimp for the purpose of disease control. As diagnostic methods have improved and become more widely available, the interest in culturing specific pathogen-free (SPF) shrimp stocks in biosecure facilities has increased markedly in many regions in the Americas. The methods being used in shrimp disease diagnostic laboratories in the Americas were recently surveyed. Of the 40 laboratories contacted, 27 responded to the survey. Approximately 75% of the labs responding to the survey provide diagnostic services using both molecular (PCR, RT-PCR and gene probes) and classical (routine histology and microbiology) methods, while nearly all (93%) of the diagnostic labs offer diagnostic testing and screening services based on molecular methods (i.e. assays with gene probes and PCR/RT-PCR).
  • Conference paper

    Progress and current status of diagnostic techniques for marine fish viral diseases at the SEAFDEC Aquaculture Department. 

    GD Lio-Po, ER Cruz-Lacierda, LD de la Peña, Y Maeno & Y Inui - In Y Inui & ER Cruz-Lacierda (Eds.), Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The incidence of unexplained mortalities among marine finfish in the Philippines has been increasingly observed. Considering that outbreaks of viral infections affecting similarly cultured marine fishes such as grouper and seabass were reported in many countries, a comprehensive diagnostic program to meet the challenge was initiated at the Aquaculture Department, Southeast Asian Fisheries Development Center (SEAFDEC-AQD)with funding from the Japanese Trust Fund Fish Disease Project. This activity was further boosted by the Japan International Research Center for Agricultural Sciences (JIRCAS). Overall, the program involved the staff of the marine finfish hatchery and the Fish Health Section. Cases of unexplained mortalities observed in the hatchery were referred to the Fish Health Section. Detailed information on the culture histories of each case were provided by the hatchery staff. Diagnostic tests were performed on each case and those with potential indication of viral etiology were processed for virus detection. Presumptive diagnosis of viral infections was based on typical signs, cell culture isolation histopathology and in-vivo pathogenicity tests. Confirmatory tests to identify specific viruses include RT-PCR, FAT and electron microscopy. The highlights of outbreaks of viral nervous necrosis and other virus-associated infections among marine finfish at SEAFDEC-AQD are presented.
  • Conference paper

    Selection of probiotics for shrimp and crab hatcheries. 

    CR Lavilla-Pitogo, DD Catedral, SAG Pedrajas & LD De la Peña - In Disease Control in Fish and Shrimp Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques: Proceedings … Aquaculture in Southeast Asia – Diagnosis and Husbandry Techniques, 4-6 December 2001, Iloilo City, Philippines, 2002 - Aquaculture Department, Southeast Asian Fisheries Development Center
    A study aimed at obtaining a biological control agent against bacterial diseases, specifically luminescent vibriosis, of hatchery-reared shrimps and crabs was done to find an alternative for chemotherapy as a disease prevention and control method. Bacteria were isolated from crustacean rearing environments where luminescent vibrosis was not observed, from natural food, and from various feed ingredients. From hundreds of purified strains, 80 bacterial isolates were tested in one-on-one mixed cultures in seawater for their ability to suppress the growth of luminescent Vibrio harveyi. Of the 10 isolates exhibiting that capability, two strains were further studied: C1 from chlorella culture and P9 from a commercial probiotic preparation. However, due to the indigenous nature of C1 strain from the unicellular alga Chlorella sp. and the ease in distinguishing it from other bacteria owing to its colony morphology, more tests were done on C1 strain. To determine the suitability of C1, and to some extent P9, as biocontrol bacteria, their pathogenicity against crab larvae and shrimp postlarvae, and their ability to become associated or incorporated into the larvae were determined. Incorporation into the rotifer, Brachionus, was also tested. Due to the positive results obtained in the incorporation experiments, the growth of strain C1 in microbiological media and unrefined media prepared from agricultural by-products was also tested.