Recent Submissions

  • Article

    Abdominal segment deformity syndrome (asds) and fused body segment deformity (fbsd) in cultured Penaeus indicus 

    The abdominal segment deformity disease (ASDD) is a new shrimp disease reported only in cultured Penaeus vannamei in Thailand. Shrimp with ASDD have deformed abdominal segment, jagged gut line and bumpy surfaces. Similar signs were observed in cultured P. indicus in the Philippines. However, aside from the signs described for ASDD, some P. indicus showing abdominal segment deformity syndrome (ASDS) had more severe deformities up to the extent that the number of body segments was reduced due to fusion. Shrimp with fused body segment deformity (FBSD) had four instead of five pairs of legs. To account the prevalence of the deformities in P. indicus, shrimp were classified into grossly normal shrimp (NS), shrimp with abdominal segment deformity syndrome (ASDS) and shrimp with fused segments (FBSD). Out of the shrimp sampled, 83.4 ± 5.4% was NS, 10.9 ± 6.2% was ASDS and 5.7 ± 3.0% was FBSD. Morphometric characteristics of the shrimp were measured. There was no significant difference in body weight (BW) among male and female NS, ASDS and FBSD. In both sexes, total length (TL) of FBSD was significantly shorter compared to NS and ASDS. Shrimp samples were also screened to be negative for known infectious viral diseases including white spot syndrome virus (WSSV), infectious hypodermal and haematopoietic necrosis virus (IHHNV), infectious myonecrosis virus (IMNV), P. vannamei nodavirus (PvNV), Macrobrachium rosenbergii nodavirus (MrNV) and Taura syndrome virus (TSV). Occurrence of ASDS and FBSD in post-larvae (PL) produced from captive and wild spawners were also determined. Based on a tank experiment, no significant difference was detected between the percentages of ASDS in PL produced from wild or captive spawners but FBSD was only noted in PL produced from the latter. Deformities generally did not affect the size of P. indicus except for the reduced length of shrimp with FBSD which when coupled with missing pleopods could lead to major economic loss for shrimp farmers if not addressed properly.
  • Book chapter

    Sustainable milkfish production in marine fish cages through strong government support and effective public-private partnerships: a case study from Panabo City Mariculture Park in Davao del Norte, Philippines 

    FG Ayson, AM Ventura & EG de Jesus-Ayson - In W Miao & KK Lal (Eds.), Sustainable intensification of aquaculture in the Asia-Pacific region. Documentation of successful practices, 2016 - FAO Regional Office for Asia and the Pacific
    This case study presents the successful practice of sustainable intensification of milkfish aquaculture in marine fish cages under semi-intensive grow-out conditions in the Panabo City Mariculture Park (PCMP) in Davao del Norte, Philippines. Established in 2006, PCMP became operational through the promulgation of a City Ordinance declaring 1 075 hectares of municipal waters in Panabo City as a Mariculture Development Zone/Park. The operations of PCMP were so successful that in just five years it became the third largest among the 63 operational MPs in the Philippines during 2011, with 86 private investors-locators operating a total of 322 units of cages. At present, a total of 372 units of fish cages are operating in the mariculture park (MP). A combination of factors contributed to the successful operation of PCMP, but the success is usually attributed to the effective partnership between the government (both local and national) and the private sector. The Comprehensive MP City Ordinance that governs the PCMP is strictly implemented and includes, among others, the tenurial rights and access to locators. Regulations on distances between cages are strictly enforced and security measures in the total area are jointly undertaken by the government and the locators. The national government, through the Bureau of Fisheries and Aquatic Resources-National Mariculture Center (BFAR-NMC), provides technical support in all aspects from stocking to harvest during the production cycle. BFAR-NMC staff conduct regular periodic sampling of the stocks and compute feeding rates for the stocks which are implemented by the technicians/caretakers. Likewise, BFAR-NMC staff regularly monitor the water quality of the MP and the health status of the stocks. Since it became operational in 2006, the PCMP did not report a single incident of mass fish kill, which indicates that the technical guidelines of MP operations are strictly followed. Workers are trained and organized into groups by BFAR-NMC such as caretakers, cage framers, netters, harvesters, fish processors, and others, and actively participate in discussions related to MP operations to ensure protocols are properly followed. Harvests of stocks are done by skilled workers trained by BFAR-NMC, all done in the “Bagsakan Center” or fish landing area and are well-coordinated. The support facilities in the fish landing area are provided by both the local and national government and the PCMP Producers Association. The operators provide complete data for their operations to BFAR-NMC for record keeping. The strong partnership between the national government through BFAR-NMC, the local government unit, the investors, as well as the acceptance and support from the community for the PCMP is the hallmark of its success.
  • Conference paper

    Latest research on acute hepatopancreatic necrosis disease (AHPND) of penaeid shrimps 

    I Hirono, S Tinwongger, Y Nochiri & H Kondo - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Acute hepatopancreatic necrosis disease (AHPND) is caused by unique strains of Vibrio parahaemolyticus (VPAHPND) and V. harveyi that have transferrable plasmid carrying the virulent PirAB-like toxin genes. The genomes of VPAHPND strains and V. harveyi from Thailand and Viet Nam, respectively, have been characterized by our group. The genome of VPAHPND strains from Mexico, Viet Nam, and China have also been studied by other groups. We have developed a conventional polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) methods for the detection of AHPND using a primer set that targets the PirAB-like toxin genes of VPAHPND. We have characterized the toxin genes of VPAHPND strains and also constructed a recombinant plasmid (broad host range) carrying PirAB-like toxin genes. Non-VPAHPND strain N7 which does not carry the plasmid and strain FP11 which is carrying a plasmid not coding for the toxin genes were transformed with the plasmid carrying PirAB-like toxin genes. As a result, the transformed N7 and FP11 strains became virulent and killed whiteleg shrimp (Penaeus vannamei) similar to or at par with the virulence of VPAHPND strain. We then fed the whiteleg shrimp with commercial feed containing the formalin-killed VPAHPND strain. After 2 days of feeding, all of the whiteleg shrimp died. These results clearly indicate that the PirAB-like toxin is the virulence factor of VPAHPND.

    We have been investigating the virulence mechanism of the PirAB-like toxin produced by VPAHPND strains. First, we calculated the copy number of plasmid encoding the PirAB-like toxin genes of several VPAHPND strains. The copy number of the plasmid varied, ranging from 1 to 36 copies. Interestingly, VPAHPND strains carrying low copy number of plasmid were more virulent than VPAHPND strains carrying high copy number of the plasmid. These results imply that the copy number of toxin genes is not an important factor responsible for the degree of virulence of the VPAHPND strains. We are also studying other factors associated with the virulence of PirAB-like toxin. Likewise, we are developing prevention methods against AHPND including the use of formalin-killed cell vaccine, IgY additive in feed, and nano-bubble treatment of rearing water. This paper summarizes the current R&D on the disease.
  • Article

    Embryonic and larval development of hatchery-reared silver therapon Leiopotherapon plumbeus (Perciformes: Terapontidae) 

    FA Aya, VSN Nillasca, LMB Garcia & Y Takagi - Ichthyological Research, 2016 - Springer Verlag
    The embryonic and larval development of hatchery-reared silver therapon Leiopotherapon plumbeus are described to provide essential information on the early life history of this species. Egg size, larval size at hatching, yolk resorption rate, onset of feeding and development of some morphological characters were examined. Fertilized eggs (430–610 µm in diameter) were spherical, yellowish, demersal and slightly adhesive. First cleavage occurred 6 min post-fertilization and embryos hatched 21–24 h post-fertilization under ambient temperature of 27.5 ± 0.1 °C. Newly hatched larvae [1.79 ± 0.04 mm in total length (TL)] with yolk volume of 0.579 ± 0.126 mm3 had no functional or pigmented eyes, mouth or digestive tract. The eyes became fully pigmented and mouth opened [31 and 36.5 hours post-hatching (hph)] shortly before yolk resorption at 39 hph and when larvae had grown to 2.65 ± 0.14 mm in TL. Some morphological characters such as total length, pre-anal length and eye diameter decreased following yolk resorption, which also coincided with the development of foraging capacities shortly before exogenous feeding was initiated. L. plumbeus larvae initiated exogenous feeding at 54 hph, indicating a short (15 h after yolk resorption) transitional feeding period. Larval growth at the early stages of development (54–72 hph) was rapid and steadily increased from 288 to 720 hph, when larvae, 12.05 ± 4.02 mm in TL, closely resembled the external characteristics of their adult conspecifics.
  • Conference paper

    OIE initiatives on acute hepatopancreatic necrosis disease (AHPND) and other aquatic animal diseases in Asia 

    H Kugita - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The World Organization for Animal Health (OIE) is an intergovernmental organization established in 1924 responsible for improving animal health and welfare worldwide to facilitate safe international trade of animals and animal products while avoiding unnecessary impediments to trade. OIE, as a reference organization of the World Trade Organization (WTO), works to set and update its international standards (OIE Codes and Manuals) regularly through transparent and democratic procedures. The Aquatic Code defines an OIE list of notifiable aquatic animal diseases according to the criteria for listing, which comprise consequences, spread and diagnosis. To be listed, a disease should meet the criteria of each characteristic defined in the Aquatic Code. The acute hepatopancreatic necrosis disease (AHPND) has been officially included in the OIE-listed diseases since May 2015 and officially enforced since 1 January 2016. To fulfill its overall vision which can be summarized by its slogan Protect animals and Preserve our Future, the OIE Regional Representation in Tokyo, Japan and Sub-Regional Representation in Bangkok, Thailand, are working in concert to provide regionally adapted services to OIE Members so that surveillance and control of animal diseases in the region may be strengthened.
  • Conference paper

    Regional response on AHPND and other emerging shrimp diseases in the Asia-Pacific 

    EM Leaño - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Transboundary aquatic animal diseases are among the major concerns for establishing biosecurity measures and strengthening of aquatic animal health (AAH) management capacity (including emergency preparedness) in the region. In aquaculture, biosecurity and AAH management entails protection of fish or shellfish from infectious agents (viral, bacterial, fungal or parasitic) as well as prevention of disease spread from one area to another. Several transboundary aquatic animal diseases have swept the region over the past 25 years causing massive economic and social losses. These include spread and outbreaks of epizootic ulcerative syndrome (EUS) in freshwater fish, viral nervous necrosis (VNN) in marine fish, viral haemorrhagic septicaemia (VHS) in marine and freshwater fish, and several viral diseases in shrimps (e.g. white spot disease [WSD], infectious haematopoietic necrosis [IHHN]). The spread of these transboundary diseases clearly demonstrates the vulnerability of the aquaculture industry to disease emergence where impacts have been aggravated by the lack of effective preparedness and response when diseases emerge.

    Recently, outbreaks of acute hepatopancreatic necrosis disease (AHPND), popularly known as early mortality syndrome (EMS), among cultured shrimps were reported in China and Viet Nam (2010), Malaysia (2011), Thailand (2012), Mexico (2013) and the Philippines (2014). There have been reports of its spread in South American countries but limited report is available in this regard. This disease caused significant losses in the production of Penaeus monodon and P. vannamei in the affected countries. NACA s regional response to this disease during its initial outbreak in Viet Nam, Thailand and Malaysia signified that improved control on transboundary diseases and emergency preparedness are still needed in the region. In collaboration with international organizations (OIE, FAO), NACA has implemented awareness programs, efficient information dissemination, and emergency regional expert consultation to address this disease problem. OIE and FAO also deployed experts to assess the disease and identify the pathogen involved. All of these efforts, together with subsequent studies on prevention and disease management, have paved the way in preventing further spread of this disease to other shrimp-producing countries so far. However, the risk is still very high that this disease will spread, as transboundary movement of live shrimps within and outside the region is inevitable. In addition, other emerging diseases are now affecting production of major cultured shrimps in the region. These include hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP) with confirmed reports from China, Viet Nam, Thailand, Malaysia and Indonesia (unconfirmed reports from India), and viral covert mortality disease (VCMD) which was reported to be affecting cultured shrimps in China.

    By and large, outbreaks of damaging aquatic animal diseases are likely to continue and the potential consequences are likely to increase with the expansion (intensification) of aquaculture systems and introduction of new species for culture. Consequently, the risks associated with emerging and transboundary diseases are shared - shared water bodies and epidemiological links through trade (especially live movement) - thus, a collaborative approach in dealing with these diseases is therefore warranted and necessary.
  • Conference paper

    Community-based stock enhancement of abalone, Haliotis asinina in Sagay marine reserve: Achievements, limitations and directions 

    ND Salayo, RJG Castel, RT Barrido, DHM Tormon & T Azuma - In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development Center
    The Sagay Marine Reserve (SMR) under the National Integrated Protected Area System (NIPAS) is one of the many reef areas in the Visayan Sea in the central part of the Philippine archipelago. The SMR covers 32,000 ha or 59% of coastal waters north of the mainland Sagay City. Donkey’s ear abalone is one of the most sought mollusks traded by small-scale fishers in Molocaboc Island located within the SMR. High buying prices in local and international markets compared with other fish catch motivated fishers to target abalone and caused its overfishing. SEAFDEC/AQD, with support from the Government of Japan Trust Fund (JTF), conducted a community-based stock enhancement through a tri-party collaboration between the fisherfolks of Molocaboc Island, the Sagay local government at the village and city levels, and SEAFDEC/AQD. The study showed that the decision and implementation of stock enhancement and the definition of its objectives and relevance involves the strong engagement with stakeholders. For over a period of eight years (2007-2014), we learned that stock enhancement necessarily involve high financial investments and enormous transaction cost over a long period of time which are often not affordable to local governments of coastal communities in Southeast Asia. Thus, community-based collaborations may help achieve enhancement and restocking goals.
  • Conference paper

    Current status of acute hepatopancreatic necrosis disease (AHPND) and other transboundary diseases of farmed shrimps in Indonesia 

    MS Hastuti & Desrina - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Transboundary diseases have been a constant challenge for the aquaculture industry in Indonesia. In spite of this, Indonesian aquaculture has experienced a steady growth since 2010. Early mortality syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) is a serious emerging transboundary disease of cultured shrimp that has not been reported in Indonesia. On the contrary, hepatopancreatic microsporidiosis (HPM) was first detected in 2015. Other previously reported transboundary diseases of shrimp and fish include white spot disease (WSD), Taura syndrome and infectious myonecrosis (IMN), and viral nervous necrosis (VNN) and koi herpesvirus (KHV), respectively. These diseases have been included in the surveillance program conducted in 2016. To avert the spread of these transboundary pathogens in the Indonesian aquaculture facilities and natural waters, competent authorities have been tasked to implement stringent control measures including government policy and regulation, active and passive surveillance, and strengthening farmers and stake holders awareness of the importance of disease control and health maintenance.
  • Conference paper

    Current status of shrimp farming and diseases in Cambodia 

    O Lang & M Sothea - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    The farming of penaeid shrimps in Cambodia began in 1989 and has significantly expanded since 1991. Shrimp cultivation has been carried out in the four coastal provinces, i.e. Kampot, Kep, Preah Sihanouk Ville, and Koh Kong. Black tiger shrimp (Penaeus monodon) and whiteleg shrimp (P. vannamei) are the main species being cultured extensively and intensively in brackishwater ponds in Kampot, Kep, and Preah Sihanouk Ville, and Koh Kong, respectively. Extensive shrimp ponds were constructed close to the mangrove areas with some containing mangroves within the pond and stocking density ranging from 5,000 to 20,000 postlarvae/ha. However, the productivity remains low at >100 kg/ ha/ year. On the contrary, intensive culture has a stocking density ranging from 300,000 to 500,000 postlarvae/ha. While high cost of investment for farm establishment, pond construction and farm operation are required, productions of newly established farms have reached 7 to 8 metric tons (MT) /ha per crop.

    The occurrence of white spot disease, monodon baculovirus disease, and yellow head disease was first reported in 1999 among cultured P. monodon in Koh Kong province causing a number of farmers to stop the intensive cultivation of black tiger shrimp. To date, only a small proportion of shrimp farmers have ventured into extensive shrimp farming with approximately 10 ha of shrimp areas currently in operation. To mitigate the negative impacts of shrimp diseases and promote the expansion of the shrimp industry in Cambodia, development of a national reporting system for aquatic animal diseases; capacity building for detection, monitoring and disease surveillance; creation of National Guidelines On Good Shrimp Aquaculture Practices; establishment of subresearch centers and concomitant funding support for marine aquaculture development and extension services; establishment of local shrimp hatcheries and provision of hands-on trainings for farmers; and strengthening collaborations among provincial officers, researchers and farmers network should be accordingly instituted.
  • Conference paper

    Current status of acute hepatopancreatic necrosis disease (AHPND) of farmed shrimp in Malaysia 

    BC Kua, A Iar, A Siti Zahrah, J Irene, J Norazila, NY Nik Haiha, Y Fadzilah, M Mohammed, B Siti Rokhaiya, M Omar & TP Teoh - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    A report about a disease problem in cultured whiteleg shrimp (Penaeus vannamei) was first received by the National Fish Health Research Center (NaFisH) in 2011 from Perak State showing signs of white feces and slow death leading to serious mortality rate. Later, in September of the same year, the Malaysian Shrimp Farmers Association (MSFA) reported to Department of Fisheries (DOF) severe mortalities in almost all of the whiteleg shrimp farms throughout Peninsular Malaysia. Sampling of shrimps for disease diagnosis was then conducted by NaFisH. The bacteriological and histopathological examinations revealed respectively the isolation of V. parahemolyticus and massive sloughing of hepatopancreatic epithelial cells. The disease was subsequently identified as acute hepatopancreatic necrosis disease (AHPND). From our 3-year study, the annual prevalence rates of AHPND were 50%, 26% and 73% in 2011, 2012 and 2013, respectively. At present, AHPND still persists in Malaysia but at a lower prevalence. The risk factors associated with the disease were studied, however, varied environmental and management data analyzed were inconclusive to relate any one parameter directly to the disease. To help ensure the early detection of AHPND, an experimental observation study on `gut scorecard was carried out and this was confirmed by PCR and histopathology. Validation of this technique has yet to be carried out to ensure its reliability. We also examined the potential use of some commercial products such as probiotics and disinfectants available in the market but unfortunately results showed that they were not effective in controlling AHPND. Control measures applied by the farmers such as the use of probiotics were also verified but data generated likewise appeared to be inconclusive. On the contrary, our preliminary study on the antibacterial property of the plant extracts, i.e. betel and lemongrass, incorporated in the feed showed some prophylactic and chemotherapeutic potential against AHPND. However, comprehensive in vitro and in vivo trials are still currently being undertaken to elucidate its efficacy and practical applications. To ensure the shrimp industry s sustainability in Malaysia, results of our ongoing and future studies aimed at preventing and controlling unwarranted outbreaks of AHPND and other emerging transboundary diseases of penaeid shrimps will be continually disseminated to shrimp farmers and pertinent stakeholders.
  • Article

    Acute toxicity of water-accommodated fraction and chemically enhanced WAF of bunker C oil and dispersant to a microalga Tetraselmis tetrathele 

    SS Santander-Avanceña, RB Sadaba, HS Taberna Jr., GT Tayo & J Koyama - Bulletin of Environmental Contamination and Toxicology, 2016 - Springer Verlag
    This study assessed the toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of bunker C oil and dispersant (DISP) to a microalga, Tetraselmis tetrathele. The 72-h median effective concentration (72-h EC50) of CEWAF and DISP were determined at 3.30 % and 2.40 %, respectively. The no observed effect concentration (NOEC) of CEWAF to T. tetrathele was at 2.0 % and lowest observed effect concentration (LOEC) was at 3.0 % while NOEC and LOEC of DISP to T. tetrathele were determined at 1.0 % and 2.0 %, respectively. The addition of dispersant to oil increased the amount of total PAH present in the CEWAF test solutions. DISP alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant.
  • Conference paper

    Current status and impact of early mortality syndrome (EMS)/acute hepatopancreatic necrosis disease (AHPND) and hepatopancreatic microsporidiosis (HPM) outbreaks on Thailand s shrimp farming 

    S Putth & J Polchana - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Outbreak of early mortality syndrome (EMS) or acute hepatopancreatic necrosis disease (AHPND) in whiteleg shrimp (Penaeus vannamei) and black tiger shrimp (P. monodon) was first documented in August 2011 in Eastern Thailand. The disease subsequently spread to almost all shrimp production areas in 2012 until the early part of 2016. These episodes of AHPND outbreaks consequently impacted the shrimp industry as evidenced by significant reduction in the production of farmed shrimps, shortage of raw materials for the shrimp export industry, and reduction of global shrimp supply from Thailand. Following the discovery of Vibrio parahaemolyticus as the causal agent of AHPND, PCR techniques subsequently became available for the rapid and accurate detection of AHPND in cultivated shrimps. The Department of Fisheries (DOF) consequently included AHPND in the National Surveillance Program focusing on the investigation of risk factors responsible for the outbreak and concomitant spread of the disease. As a result, the quality of broodstock and postlarvae (PL) and as well as farm management practices, i.e. pond bottom and water preparation, stocking density, feeds and feeding practices, and water quality fluctuations were identified as key risk factors associated with AHPND outbreaks. By and large, the DOF has undertaken mitigating measures to control and prevent further outbreaks of AHPND including the improvement of sanitation in marine shrimp broodstock and PL hatcheries, quality evaluation and disease screening of broodstocks and PL, detection of pathogens in soil and water samples, and acquisition of new broodstocks for improved genetic diversity. To date, Thailand s shrimp industry has gradually recovered from the devastating effects of AHPND since 2015.

    Heptopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP), a sporeforming microsporidian, is another emerging disease of cultured penaeids in Thailand. EHP was first documented in farmed P. monodon in 2004, however, its impact was not clearly evaluated at that time. EHP was again observed in P. vannamei in 2014 at the same period of AHPND outbreak in Thailand. In the field, EHP could be transmitted horizontally through feeding of the EHPcontaminated feed and feces from infected shrimp. Samples collected from numerous shrimp farms showed that EHP was heavily present in both ponds with successful and failed crops indicating that EHP infection in shrimp may not be a significant contributing factor to a failed production run. In vitro challenge likewise showed that there was no correlation between EHP and white feces syndrome. However, EHP infection at significantly high levels could affect shrimp growth. One of the mitigating measures to control EHP infection in cultured shrimp is the reduction of contamination in hatcheries and grow-out facilities.

    Despite the negative impacts of AHPND and HPM on the shrimp industry of Thailand, all parties of the shrimp sector have been working in concert to attain the projected annual shrimp production volume of approximately 300,000 metric tons (MT) in 2016.
  • Article | Short report

    Early appearance of the retinal tapetum, cones, and rods in the larvae of the African catfish Clarias gariepinus 

    G Kawamura, T Bagarinao, J Justin & CY Chen - Ichthyological Research, 2016 - Springer Verlag
    In the retina of the African catfish Clarias gariepinus, the pigment epithelium and the tapetum were formed in newly hatched larvae, the cones developed within 2 days, and the rods within 3 days after hatching. The retinal tapetum shone under surface light under a light microscope; the shine was located in the apical projections of the pigment epithelial cells. Early appearance of the retinal elements enables African catfish larvae to see and feed well even in dim light.
  • Conference paper

    Fishery resource enhancement: An overview of the current situation and issues in the southeast Asian region 

    MJH Lebata-Ramos & EF Doyola-Solis - In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development Center
    The total global production from capture fisheries has plateaued since the mid 90s. This stagnation in production or reduced productivity of the world’s coastal and marine wild fisheries is caused by overfishing and degradation of habitats through coastal development and destructive fishing methods. Reports have shown that if the current fishing trends continue, all of the commercial fisheries will have collapsed by 2050. To boost production, scientists, fisheries managers, government agencies, and NGOs have been looking at ways of enhancing fish stocks. Replenishing depleted stocks may be done by regulating fishing effort, restoring degraded nursery and spawning habitats or through resource enhancement. Resource enhancement using individuals reared in aquaculture facilities or seed stocks abundant in the wild is becoming a popular method of supplementing depleted stocks. It is one of the many strategies that could help address the decreasing fisheries production in the wild. A brief history of resource enhancement, the aquatic species released in the different countries in the region, the reasons for releasing stocks, and the issues involved, are discussed briefly in this paper. Among the main reasons for resource enhancement are to increase production or enhance stocks and increase food supply and/or family income. Other reasons include protection of endemic and maintenance of endangered species, rehabilitation of degraded natural habitats and for recreation fisheries, among others. Age or size of seeds, seed quality, genetics, governance, economics, biodiversity conservation, politics, and the introduction of exotics are among the resource enhancement issues identified in the region.
  • Conference paper

    Status of transboundary diseases of penaeid shrimps in Singapore 

    Y Wong & J Jiang - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
    Singapore has a small shrimp farming industry with approximately 54 metric tons (MT) of shrimps produced in one year from both land and coastal farms. There is also one shrimp farm producing broodstock for export. Singapore has the capability to diagnose acute hepatopancreatic necrosis disease (AHPND) through histopathology and the isolation of its causal agent which is Vibrio parahaemolyticus. The polymerase chain reaction (PCR) method for AHPND detection in shrimp is currently being undertaken to further strengthen its laboratory and diagnostic capacity. Notably, Singapore is still AHPND-free. On the contrary, white spot disease caused by white spot syndrome virus (WSSV) is a disease of concern as it affects the trade for ornamental crustaceans. Singapore has an active surveillance program for WSSV and other transboundary pathogens of penaeid shrimps. Positive detections would be followed by movement controls and stamping out protocols.
  • Conference paper

    Aquaculture-based restoration and stock enhancement of tiger shrimps in the Philippines 

    JP Altamirano, N Salayo, H Kurokura, H Fushimi & S Ishikawa - In K Hajime, T Iwata, Y Theparoonrat, N Manajit & VT Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium … Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015, 2016 - Training Department, Southeast Asian Fisheries Development Center
    In central Philippines, the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD), with strong collaboration and support from the Research Institute for Humanity and Nature (RIHN) of Kyoto, Japan, has been looking into the stock enhancement of tiger shrimp Penaeus monodon in the New Washington Estuary (NWE), province of Aklan, central Philippines. The NWE was a productive fishing ground that has been suffering from degenerating brackishwater fisheries and estuarine environment. Average daily catch declined from 24 kg in 1970s to only 0.7 kg at present. Shrimp fisheries, the most important livelihood, declined in quality and quantity. Tiger shrimps were abundant in catch until the early 1990s when these were observed to decline in volume, replaced by smaller and cheaper species. This was coincidental with the rapid decline in mangrove cover for ponds and huge increase in fishing pressure. It is clear that crucial interventions are required to restore the tiger shrimp fisheries in the NWE in order to increase income of local fishers, while promoting reduction of fishing gears and restoration of mangroves. Stock enhancement of tiger shrimps shows good potential in answering these needs. Site-specific assessments were conducted to evaluate prospects of shrimp stock enhancement in NWE. Conservative simulations of capture of released stocks showed that fishers can increase income by 300%. To decrease fishing pressure in the area, number of gears per fisher may have to be reduced but shrimp catches will be relatively high-priced. Comparative experiments using aquaculture techniques were done to identify strategies especially in the delicate intermediate acclimation rearing. Aquaculture protocols like those for pond preparation were also adapted to be used in a mangrove pen nursery rearing system for shrimps. Supplemental feeding with formulated feeds increased carrying capacity of the culture area, while enhancing growth and survival of stocks. Culture experiments showed that shrimps grow to 0.5 g within 1 mo and >1g in 2 mo. High stocking density of 40-60 shrimps m-2 can be used for <2 mo rearing in a mangrove pen. Release experiments showed that 60-d old shrimps have higher chances of survival when released in the estuaries. With strong support from local communities, government and other sectors, together with effective management and law enforcement, aquaculture-based stock enhancement of tiger shrimps can be a viable intervention to restore livelihood and promote estuarine rehabilitation in the NWE.
  • Article

    Biomass production, proximate composition and fatty acid profile of the local marine thraustochytrid isolate, Schizochytrium sp. LEY7 using low-cost substrates at optimum culture conditions 

    G Ludevese-Pascual, M Dela Peña & J Tornalejo - Aquaculture Research, 2016 - John Wiley and Sons
    This study was conducted to investigate low-cost substrate alternative and the optimum culture conditions in mass producing the local marine thraustochytrid, Schizochytrium sp. LEY7 isolated from the mangrove leaves of Baybay, Southern Leyte Philippines. Results showed that Schizochytrium sp. LEY7 is able to utilize commercial grade glucose and yeast extract from NaCl-treated baker's yeast as source of carbon and micronutrients respectively. Cost of mass producing the thraustochytrid isolate using the alternative production substrates was substantially reduced. Incubation temperature and salinity levels were the two growth factors significantly affecting the biomass production of the isolate. The short duration of lag phase shown by the isolate suggests a growth advantage in that cells are readily able to adapt to their new environment. Total lipids averaged to 19.4%. Principal fatty acids were palmitic acid (C16:0) with 33.52% and docosahexanoic acid (DHA, C22:6n-3) with 39.92% proportion to total fatty acid. Eicosapentaenoic (C20:5n-3, 1.01%) and arachidonic (C20:4n-3, 0.90%) are present but in relatively lower amount. Our findings showed the potential of low-cost substrate in mass producing the local thraustochytrid isolate, Schizochytrium sp. LEY7 as lipid and polyunsaturated fatty acid source in aquaculture. Biomass production was enhanced by optimizing the culture conditions.
  • Article

    Test of refined formulated feed for the grow-out culture of tropical abalone Haliotis asinina (Linnaeus 1758) in concrete land-based tanks 

    MN Bautista-Teruel, JRH Maquirang, MR de la Peña & VT Balinas - Journal of Shellfish Research, 2016 - National Shellfisheries Association
    A refined formulated feed for the grow-out culture of tropical abalone Haliotis asinina was evaluated to assess its suitability for a shorter culture period (<8 mo). Refinement procedures focused on the application of additional binder (sodium alginate), use of different feed forms (molo and noodle forms), and incorporation of Spirulina spp. as alternate protein source in partial replacement of other protein sources. Groups of 22 postlarval abalone with mean initial shell length (SL, 29 ± 0.01 mm) and weight (5.67 ± 0.06 g), harvested from the mollusc nursery of Southeast Asian Fisheries Development Center, Aquaculture Department in Tigbauan, Iloilo, were stocked each as replicate in five plastic trays measuring 31.7×43.5×9.0 cm. The trays were suspended in five 1×2×1-m concrete land-based tanks representing the five dietary treatments. Abalone were fed either the refined formulated diet,molo form(RF-M), refined formulated diet, noodle form(RF-N), unrefined formulated diet, noodle form(UF-N), unrefined formulated diet, molo form (UF-M), and seaweed (NF), as the reference diet. Formulated diets and natural food were given at 2%-3% and 10%-15% (wet weight) of the body weight, respectively, once daily at 1600 h for 180 days. Water quality measurements were maintained at desired levels. A flow-through filtered seawater systemwith continuous aeration was provided in each tank. A parametric one-way analysis of variance (ANOVA) and Tukey's post hoc test were used to test the differences in abalone SL, weight gain (WG), and specific growth rate (SGR) while nonparametric Kruskal-Wallis test was used for daily growth increase in SL (DGSL) and feed conversion ratio (FCR) among the various dietary treatments. Percent diet water stability and apparent digestibility coefficient for dry matter (ADMD) and apparent digestibility of seaweed as ingredient were, likewise assessed. A Hedonic scale taste test analysis was done to assess differences in abalone meat quality. Highest mean WG (239.17% ± 26.05%), mean SL increase (91.51% ± 3.28%), DGSL (2,296.67 µm/day), SGR (4.04 ± 0.27) were attained with abalone fed RF-N. Values, however, were not significantly different (P > 0.05) for all growth parameters in RF-M except for percent increase in SL at 74.25 ± 3.11. Abalone given UF-N and UF-M showed significantly lower mean WG and SL. Survival was high and was significantly different (P < 0.05) between treatments. The highest FCR was obtained with abalone fed seaweeds. Apparent digestibility for dry matter of both the RF and UF were high at 95.67% ± 1.17% and 95.95% ± 0.45%, respectively. Apparent digestibility of ingredient seaweed was 99.4% ± 1.38%. Regression analysis of data showed better percent water stability for RF (57%; R2 = 0.954) compared with UF (38%; R2 = 0.790) after 24 h. Meat quality of the final product assessed through Hedonic scale taste testing and one-way ANOVA did not show any significant variations in taste, texture, color, odor, and general acceptability. Results have demonstrated that the refinement done on the formulated feed may enable the abalone to grow to its marketable size of about 5-6 cm in a shorter culture period (180 days) in concrete land-based tanks.
  • Book chapter

    Important diseases of Penaeid shrimps 

    GD Lio-Po & EM Leaño - In IC Liao, NH Chao & EM Leaño (Eds.), Progress of Shrimp and Prawn Aquaculture in the World, 2016 - National Taiwan Ocean University; The Fisheries Society of Taiwan; Asian Fisheries Society; World Aquaculture Society
    In tropical Asia, the two main species of penaeid shrimps that are widely cultured are the black tiger shrimp (Penaeus monodon) and the Pacific white shrimp (Penaeus (Litopenaeus) vannamei). The former species is indigenous in most Asian countries while the latter is indigenous in the Americas and was introduced to Asian countries in the late 1990s. In this chapter, only details of the economically-important microbial infections in Asia in these two penaeid shrimps are presented and arbitrarily grouped as viral, bacterial, fungal and parasitic diseases. Viral infections are divided further into two groups: DNA viruses; and, RNA viruses. The infections attributed to DNA viruses are: White Spot Disease (WSD) Disease, Penaeus stylirostris densovirus (PstDNV) previously known as Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) Disease, Penaeus monodon densovirus (PmDNV) formerly known as Hepatopancreatic Parvo-like Virus (HPV) Disease and Penaeus monodon nucleopoly-hedrovirus (PemoNPV) previously known as Monodon Baculovirus (MBV) Disease. The shrimp infections caused by RNA viruses are: Yellow Head Virus (YHV) Disease, Taura Syndrome Virus (TSV) Disease, and Infectious Myonecrosis Virus (IMNV) Disease. For bacterial diseases, the list includes Luminous Bacterial Disease, Non-luminous Vibrio Infections, and Acute Hepatopancreatic Necrosis Disease (AHPND). Fungal disease includes Larval mycosis, while parasitic disease includes the current emerging threat to the shrimp industry, the Hepatopancreatic Microsporidiosis caused by Enterocytozoon hepatopenaei (EHP).

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