Now showing items 1-20 of 2952

    • 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.
    • Article

      Colour discrimination in dim light by the larvae of the African catfish Clarias gariepinus 

      G Kawamura, T Bagarinao, PK Hoo, J Justin & LS Lim - Ichthyological Research, 2017 - Springer
      Many demersal fish species undergo vertical shifts in habitats during ontogeny especially after larval metamorphosis. The visual spectral sensitivity shifts with the habitat, indicating a change in colour vision. Colour vision depends on sufficient ambient light and becomes ineffective at a particular low light intensity. It is not known how fishes see colour in dim light. By means of a behavioural experiment on larval African catfish Clarias gariepinus in the laboratory, we determined colour vision and colour discrimination in dim light. Light-adapted larvae were subjected to classical conditioning to associate a reward feed with a green or a red stimulus placed among 7 shades of grey. The larvae learned this visual task after 70 and 90 trials. A different batch of larvae were trained to discriminate between green and red and then tested for the ability to discriminate between these colours, as the light intensity was reduced. The larvae learned this visual task after 110 trials in bright light and were able to discriminate colours, as light was dimmed until 0.01 lx, the minimal illuminance measurable in this study, and similar to starlight. The retinae of the larvae were found to be light adapted at 0.01 lx; thus indicating cone-based colour vision at this illuminance. For comparison, three human subjects were tested under similar conditions and showed a colour vision threshold at between 1.5 and 0.1 lx. For the larvae of C. gariepinus, the ability of colour discrimination in dim light is probably due to its retinal tapetum, which could increase the sensitivity of cones.
    • 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.
    • 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.
    • 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.
    • magazineArticle

      Supporting ASEAN good aquaculture practices: Utilization of alternative protein sources for aquafeed to minimize pressure on fishery resources 

      REP Mamauag - Fish for the People, 2016 - SEAFDEC Secretariat
      Aquaculture industry of Southeast Asia has been expanding steadily as a result of an increasing demand of food fish in the region as well as in the global scale. Aside from its contribution to the world’s fisheries, the aquaculture industry creates employment opportunities and provides income for the region’s fish farmers, as well as produces fish which is a major component in the diets of peoples in Southeast Asia. However, the fast development of aquaculture had been viewed as threat to sustainable capture fisheries production as the widespread use of fish by-catch in aquaculture feeds results in overexploitation of the fishery resources and to certain extent degradation of the resources. Recognizing the importance and urgency of addressing such concern, the Senior Officials of the ASEAN Member States responsible for fisheries adopted in June 2011, the Plan of Action on Sustainable Fisheries for Food security for the ASEAN Region Towards 2020 which includes provision on the need to “improve the efficient use of aquatic feeds by strictly regulating the quality of manufactured feed and feed ingredients and support continued research for developing suitable alternative protein sources that will reduce dependence on fishmeal and other fish-based products.” Along with such declaration, the SEAFDEC Aquaculture Department has been enhancing its R&D activities aimed at finding alternatives to fishmeal as feed ingredients in aquaculture feed formulations.
    • Book

      Philippine National Standard: Pasteurized crab meat 

      Bureau of Agriculture and Fisheries Standards - 2016 - Bureau of Agriculture and Fisheries Standards
      This PNS for pasteurized crab meat aims to provide a common understanding on the scope of the standard, product description, process description, essential composition and quality factors, food additives, contaminants, hygiene and handling, packaging and labeling, methods of sampling, examination and analysis, definition of defectives and lot acceptance.
    • magazineArticle

      Supporting ASEAN good aquaculture practices: Preventing the spread of trans-boundary aquatic animal diseases 

      RV Pakingking Jr. & EG de Jesus-Ayson - Fish for the People, 2016 - SEAFDEC Secretariat
      The FAO Fishery Statistics had indicated that Asia is the top producer of fish and fishery products from both capture fisheries and aquaculture. Specifically, Southeast Asia had contributed 9-31% of the total aquaculture production in Asia from 1950 to 2014 with Indonesia and the Philippines accounting for the most at 23-63% and 10-45% of the total, respectively. Aquaculture has been viewed as a solution to the growing concern on food security issues as well as for the socio-economic stability of many countries in Southeast Asia. For such reason, aquaculture operations are being intensified to compensate for the declining production from capture fisheries and in order to nail the gap between supply and demand for fish and fishery products in the world. With intensification, aquaculture production has already overtaken the contribution of capture fisheries to the world’s total fisheries production. However, concerns on the safety and quality of aquaculture products have been raised as result of intensified fish farming operations. Added to such concern is the irresponsible introduction of aquatic species for aquaculture that serve as carriers of pathogens. As a result, a large number of infectious aquatic diseases have emerged threatening the sustainability of aquaculture in the Southeast Asian region. In an effort to address the emergence of transboundary diseases in the region, the Aquaculture Department of SEAFDEC (SEAFDEC/AQD) launched a program on Healthy and Wholesome Aquaculture which includes as one of its main objectives, the need to continue improving aquaculture production through innovations in fish health management.
    • Article

      Photosynthetic responses of ‘Neosiphonia sp. epiphyte-infected’ and healthy Kappaphycus alvarezii (Rhodophyta) to irradiance, salinity and pH variations 

      IAG Borlongan, MRJ Luhan, PIP Padilla & AQ Hurtado - Journal of Applied Phycology, 2016 - Springer Verlag
      Understanding the physiological condition of seaweeds as influenced by biotic and abiotic stress is vital from the perspective of massive expansion and sustainability of seaweed-based industries. The photosynthetic responses ofNeosiphonia sp. epiphyte-infected (INF) and healthy (HEA) Kappaphycus alvarezii under various combinations of irradiance, salinity and pH were studied using photosynthesis-irradiance (P-E) curves. Measurements of algal photosynthetic rates, expressed in terms of amount of oxygen production per fresh weight biomass per unit time (mg O2 g−1 FW h−1), were carried out using the light-dark bottle technique. Neosiphonia-infected K. alvarezii (INF) had lower photosynthetic rates than healthy ones (HEA). Similarities (p > 0.05) in light-saturated photosynthesis rates (Pmax) and significant differences (p < 0.05) in initial slope of curve (α) between INF and HEAK. alvarezii suggest that both samples are adapted to similar light conditions and differs only on photosynthetic efficiency. Low Pmax (0.7–2.0 mg O2 g−1 FW h−1) and high initial saturation irradiances (Ek = 90–519 μmol photons m−2 s−1) of INF seaweeds resulted to their low photosynthetic efficiency (α = 0.002–0.010). Such decline in α is attributed to the epiphyte, as Neosiphonia sp. covered almost the entire surface of K. alvarezii. An increase in chlorophyll-a (35–42.1 vs. 27.7–31.5 μg g−1 FW, HEA) and phycobilin (1.96–2.39 vs. 1.16–1.58 mg g−1 FW, HEA) contents was also observed in INF samples, suggesting acclimation to low-irradiance conditions, as a result of competition for light between the epiphyte and host. Both INF and HEA K. alvarezii also exhibited broad photosynthetic tolerance to short-term changes in irradiance, with no photoinhibition at the highest irradiance of 850 μmol photons m−2 s−1. K. alvarezii had a euryhaline photosynthetic response, with optimum salinity of 35 psu. Photosynthetic rates increased with decreasing pH, revealing K. alvarezii’s ability to modify its photosynthetic affinity for acidic seawater conditions; yet, their underlying mechanism of response to pH shifts still need to be further examined.
    • Article

      Use of thraustochytrid Schizochytrium sp. as source of lipid and fatty acid in a formulated diet for abalone Haliotis asinina (Linnaeus) juveniles 

      MR de la Peña, MB Teruel, JM Oclarit, MJA Amar & EGT Ledesma - Aquaculture International, 2016 - Springer Verlag
      The effects of using thraustochytrid Schizochytrium sp. as source of lipid and fatty acids in a formulated diet on growth, survival, body composition, and salinity tolerance of juvenile donkey’s ear abalone, Haliotis asinina, were investigated. Treatments consisted of diets either containing a 1:1 ratio of cod liver oil (CLO) and soybean oil (SBO) (Diet 1) or thraustochytrid (Diet 2) as source of lipid and fatty acids at 2 % level. Natural diet Gracilariopsis heteroclada (Diet 3) served as the control. No significant difference in growth was observed in abalone fed Diet 3 (SGR: 5.3 % BW day−1; DISL: 265 μm day−1) and Diet 2 (SGR: 5.2 % BW day−1; DISL: 255 μm day−1). Survival ranged from 78 to 85 % for all treatments and was not significantly different from each other. A 96-h salinity stress test showed highest survival of 84 % in abalone fed Diet 2 compared with those fed diets 1 and 3 (42 %). The high growth rate of abalone fed Diet 2 and high tolerance to low salinity could be attributed to its high DHA content (8.9 %), which resulted to its high DHA/EPA ratio of 10.5 %. These fatty acids play a significant role in abalone nutrition. The fatty acid profile of abalone meat is a reflective of the fatty acid profile of the oil sources in the diet. The present study suggests that the use of Schizochytrium oil in lieu of CLO and SBO can support good growth of abalone which is comparable with abalone fed the natural seaweeds diet.
    • Book

      Philippine National Standard: Dried anchovies 

      Bureau of Agriculture and Fisheries Standards - 2016 - Bureau of Agriculture and Fisheries Standards
      This PNS for dried anchovies aims to provide a common understanding on the scope of the standard, product description, process description, essential composition and quality factors, food additives, contaminants, hygiene and handling, packaging and labeling, methods of sampling, examination and analysis, definition of defectives and lot acceptance.
    • Book

      Philippine National Standard: Live mangrove crab 

      Bureau of Agriculture and Fisheries Standards - 2016 - Bureau of Agriculture and Fisheries Standards
      This PNS for live mangrove crab aims to provide a common understanding on the scope of the standard, product description, process description, essential composition and quality factors, food additives, contaminants, hygiene and handling, packaging and labeling, methods of sampling, examination and analysis, definition of defectives and lot acceptance.
    • 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).
    • Book chapter

      Arachidonic acid is a major fatty acid in gonads of coral reef fishes and improves larval survival of rabbitfish Sigunus gutattus 

      A Suloma, DR Chavez, ES Garibay, H Furuita & HY Ogata - In SL Ortiz (Ed.), Coral reefs : ecosystems, environmental impact, and current threats, 2016 - Nova Science Publishers
      The supply of wild fry of coral reef fishes for aquaculture has resulted in the deterioration of their natural stock status, causing public concern. Through a series of studies on the establishment of artificial-fry production technologies for coral reef fishes, we found that ovary, testis, eggs and fry of coral reef fishes have high or intermediate levels of arachidonic acid (ArA), which is a relatively minor component in temperate and cold-water species. In gonadal polar lipids of selected coral reef, in particular demersal fishes (19 species), ArA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels ranged from 6.0% to 19.4%, from 0.9% to 6.2%, and from 7.9% to 27.8%, respectively. It is notable that the major highly unsaturated fatty acids (HUFA) of polar lipids in all coral reef fish gonads are DHA and ArA (not EPA) in a ratio of about 2:1. This result allowed us to speculate that not only DHA but also ArA may be nutritionally much important for egg development and larval growth in coral reef fishes.

      Thus, feeding trials were conducted to investigate the effects of dietary ArA supplementation on reproductive performance of coral reef rabbitfish (Siganus guttatus) broodstock. The number of spawning and the number of hatched larvae tended to be better in broodstock fed diets with ArA than in those fed a diet without ArA. Next, larval rearing tests were conducted to investigate survival and growth in rabbitfish fry fed live rotifers which had been enriched with or without ArA. Fry fed the rotifers enriched with a combination of DHA Protein Selco (Inve Aquaculture, Baasrode, Belgium) + 5% ArA (VEVODAR CRUDE ARACHIDONIC OIL, DSM Food Specialties, Delft, the Netherlands) showed significantly the best survival (44.4 ± 4.5% for Day 17 fry), although growth was not different among treatments. The present study indicates that ArA is not a minor component in coral reef fishes, and that dietary ArA is very promising for the improvement of fry production technologies of the coral reef fishes.
    • Book

      2015 SEAFDEC/AQD Highlights 

      Aquaculture Department, Southeast Asian Fisheries Development Center - 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The SEAFDEC Aquaculture Department is mandated to: 1) conduct scientific research to generate aquaculture technologies appropriate for Southeast Asia; 2) develop managerial, technical and skilled manpower for the aquaculture sector; and, 3) disseminate and exchange aquaculture information. The Aquaculture Department in the Philippines maintains 4 stations: the Tigbauan Main Station and Dumangas Brackishwater Station in Iloilo; the Igang Marine Station in Guimaras; and, the Binangonan Freshwater Station in Rizal. Highlights are provided of the seven research programmes and activities conducted by the department during the year 2015.
    • 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.
    • Book

      Seed production of milkfish Chanos chanos Forsskal 

      O Reyes, B Eullaran & EG Ayson - 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Series: Aquaculture extension manual; No. 63
      A 26-page manual describing the site selection, hatchery design, spawning, larval rearing, natural food production, and economic analysis for milkfish.
    • Article

      Growth and feed performance, digestibility and acute stress response of juvenile grouper (Epinephelus fuscoguttatus) fed diets with hydrolysate from milkfish offal 

      REP Mamauag & JA Ragaza - Aquaculture Research, 2016 - Wiley
      Nutritional qualities of fish processing by-products can further be improved through enzymatic hydrolysis. The objective of this study was to elucidate the efficacy of hydrolysed milkfish offal at different inclusion levels when fed to juvenile grouper, Epinephelus fuscoguttatus, with an initial body weight of 2.88 ± 0.06 g. The animals were fed for 56 days with seven diets supplemented with 0 (control), 5%, 15% and 25% of milkfish offal (MO) and milkfish offal hydrolysate (MOH). The diets were formulated to be isonitrogenous (45%) and isolipidic (11%). The diets were assigned to 21 tanks (15 fish per tank) with each diet having three replicates. Results from the experimental trials indicated that feed conversion efficiency, feed intake and weight gain of fish significantly (P < 0.05) improved when fed diets with MOH. No significant differences within the rest of the dietary treatments were observed. Survival rate (>90%) did not differ in all the dietary treatments. Proximate composition (crude protein, crude fat and ash) indicated no significant difference among fish fed from all the dietary treatments. Apparent digestibility of MOH indicated a 95% and 66% digestibility for protein and dry matter respectively. Plasma stress parameters (cortisol and glucose) were not influenced by the dietary treatment when fish were subjected to an acute stressor (5-min chasing). Liver morphology indicated normal hepatocyte shape and the presence of lipid droplets in fish fed from all the dietary treatments. The results indicated that milkfish offal processed as hydrolysate can be utilized in grouper diets and can promote growth and feed efficiency when supplied at 10–15%.