Southeast Asian Fisheries Development Center
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Characterisation of Vibrio isolates recovered from the eyes of cage-cultured pompano (Trachinotus blochii) infested with caligid parasites (Lepeophtheirus spinifer)
No full textExophthalmia was documented among sea cage-cultured pompano (Trachinotus blochii) broodstocks with caligid parasite (Lepeophtheirus spinifer) infestation in the Philippines. Following sequencing, and based on the results of both diagnostic investigations and infection experiments, V. harveyi likely had a role in the reported exophthalmia cases, and this was initiated by L. spinifer infection.This study was funded by the Government of Japan Trust Fund (GOJ-TF) through the Regional Fish Disease Project (study code:FH01-F2010-T) and in part by SEAFDEC/AQ
Immunization regimen in Asian sea bass (Lates calcarifer) broodfish: A practical strategy to control vertical transmission of nervous necrosis virus during seed production
No full textOutbreaks of viral nervous necrosis (VNN) in Asian sea bass (Lates calcarifer) at the larval stages via vertical transmission of nervous necrosis virus (NNV) from asymptomatic broodfish remain as a major deterrent during seed production. A five-year study was conducted to produce NNV-specific-free sea bass broodfish reared in land-based tanks through an annual immunization regimen with the formalin-inactivated NNV. We primarily immunized (intraperitoneal injection) sea bass juveniles (5 g) and monitored the neutralizing antibody (Nab) titers in the sera of these fish at scheduled intervals post-immunization. Nab titers in the sera of immunized fish peaked at Month 2 (titer: 1:4480 ± 1185) but thereafter gradually declined and significantly dropped (1:260 ± 83) at Month 12 post-primary immunization. Booster immunization of these fish at Month 12 post-immunization led to abrupt increases in Nab titers in booster immunized (B-Im) fish at Month 1 (1:12800 ± 6704) but thereafter declined and dropped at Month 12 (1:480 ± 165) post-booster immunization. The annual booster injections with the inactivated vaccine or L-15 (Unimmunized [U-Im]) were consecutively conducted for 4 years until the fish became sexually mature. Mature fish from both groups were successively induced to spawn twice (1-month interval) via intramuscular injection with luteinizing hormone-releasing hormone analogue (LHRH-a; 100 µg/kg BW). NNV was not detected by RT-PCR in oocytes and milts, and spawned eggs of B-Im fish. In contrast, oocytes and milts, and spawned eggs of U-Im fish were NNV positive. Spawned eggs of B-Im broodfish exhibited Nab titers ranging from 1:192 ± 34 to 1:240 while such was not detected (<1:40) in eggs of U-Im fish. Taken together, current data clearly demonstrate that annual immunization regimen with inactivated NNV vaccine is a pragmatic approach for sustaining immunocompetent sea bass broodfish reared in land-based tanks and circumvent the risk of vertical transmission of NNV from asymptomatic broodfish to their offspring under stress of repetitive spawning.This study was funded by Government of Japan Trust Fund V through the Regional Fish Disease Project (study code: FH02-F2010-T) and in part by SEAFDEC/AQD. We express our heartfelt gratitude to Dr. Takuro Shibuno and Dr. Chihaya Nakayasu, former and current GOJ-TF managers, respectively, and the Marine Fish Hatchery staff especially Mr. A. Gamuza
User acceptance of IAMSLIC digital fisheries library
No full textAbstract only.The International Association of Aquatic and Marine Science Libraries and Information Centers (IAMSLIC) through the Aquatic Commons Board approved the deployment of IAMSLIC Digital Fisheries Library in the Philippines during the 2015 Conference. The digital library utilized the LibraryBox, a portable, open source distribution tool. This standalone wireless access is ideal for fisheries schools in the area due to limited or no Internet access and intermittent electrical power conditions. With the aim of providing access to SEAFDEC Aquaculture Department (AQD) publications in these schools, more than a thousand publications that were already made available in SEAFDEC/AQD institutional repository were also added in the box. The box contained over 26,000 publications, reports, articles and documents on all aspects of fisheries that are freely available. SEAFDEC/AQD is the first institution in the country to launch t he project in July 2016 using LibraryBox. Five boxes were distributed in Philippine fisheries libraries devastated by Typhoon Yolanda or hazed by fire. This study examined the factors that influence student’s acceptance and attitude towards the IAMSLIC Digital Fisheries Library. A survey was distributed to selected fisheries and marine biology undergraduate students in the Philippines. Relevance, perceived usefulness, perceived ease of use, screen design and behavioral intention to use the digital library were determined
Mapping gendered spaces for sandfish resource management in Guimaras, Philippines
No full textWomen and men utilize spaces differently and have differential access to resources because of norms and values attached to certain places. In fisheries, the contributions of women are either overlooked or considered less valuable compared to those of men. Women often assume more traditional and supporting roles and attach lesser economic values to their activities. These gender dimensions were analyzed as part of the project on the sea ranching of sandfish (Holothuria scabra) in the Province of Guimaras, Philippines. The project was initiated by the SEAFDEC Aquaculture Department (AQD) and supported by the Australian Centre for International Agricultural Research (ACIAR) in 2015-2017 with a two-fold aim of enhancing the population of H. scabra stocks while providing a supplemental livelihood to the coastal communities reliant on fishery resources. The study highlighted the importance of analyzing the roles of women and men in the fisheries sector for the management of sandfish and other fishery resources in the intertidal zone
Biology and hatchery of mangrove crabs Scylla spp.
No full textThis manual includes the biology of crab (Scylla serrata, S. tranquebarica, and S. olivacea), and describes principles and procedures for spawning the mature crabs and rearing the zoea to ‘fly’ size crabs. It focuses on the hatchery rearing of S. serrata as the farming of this species is more economically viable than the two other species. The techniques may be modified depending on the conditions or problems encountered in a specific site.Most of the larval rearing results were based on the projects 9217 (Development of Improved Mud Crab Culture Systems in the Philippines and Australia) funded by the Australian Centre for International Agricultural Research, ICA4-CT-2001-10022 (Culture and Management of Scylla spp.) supported by the European Commission (INCO-DC) and National Mud Crab R&D Program funded by the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development of the Department of Science and Technology.ForewordIntroductionBiology of Scylla spp.Crab anatomyTaxonomy and identificationLife history and habitatFood and feedingMolting and regenerationSexual maturityMatingSpawningEmbryonic development and hatchingLarval developmentHatchery OperationsSetting up the hatcheryPreparation of tanks and seawaterProduction of natural foodManagement of broodstockLarval rearingCulture of megalopaHarvesting, packing, and transport of crabletsCommon problems and possible solutionsEconomics of mangrove crab hatcheryReferencesAcknowledgementAppendixGlossary3rd Ed
High amorphous poly-beta-hydroxybutyrate (PHB) content in a probiotic Bacillus strain displays better protective effects in Vibrio-challenged gnotobiotic Artemia
No full textIn this study, the Bacillus sp. JL47, a superior PHB-accumulating Bacillus strain identified from the previous work, was tested for its protective effects in gnotobiotic Artemia franciscana during a pathogenic Vibrio campbellii challenge. The utilization of gnotobiotic Artemia is important in this experiment because any possible microbial interference (which are naturally present in conventional culture system) are eliminated in this model culture system, hence the interpretation of the results in this mechanistic study can be more conclusive. The survival of the Artemia fed the Bacillus sp. JL47 at 1 × 107 cells mL–1 was significantly higher as compared with the challenged control and the survival was almost doubled when the dose was increased to 5 × 107 cells mL−1. However, feeding the Artemia at 106 cells mL−1 or lower showed no significant protective effects. Based on these densities, the estimated concentration of amorphous PHB showing a significant protection in Artemia was c. 2.44 mg L−1 and the effects were even better when the amorphous PHB level was increased to 12.19 mg L−1. Furthermore, feeding Bacillus sp. JL47 containing 55% amorphous PHB (on CDW) to Artemia showed a significantly higher survival in a Vibrio challenge relative to Bacillus containing 29% PHB. The data suggest that the amorphous PHB accumulated in the Bacillus sp. JL47 strain is an important determinant for the increased survival of challenged Artemia.This work was supported by the International Foundation for Science (IFS), Stockholm, Sweden [A/5040-1]; Aquaculture Department, Southeast Asian Fisheries Development Center (SEAFDEC/ AQD), Tigbauan, Iloilo, Philippines [FH-05-C2012T]; and the Bijzonder Onderzoeksfonds (BOF) [01W01311] of Ghent University, Belgium. BOF financed a doctoral grant for JLQL. The authors would like to thank Vicente Balinas for helping in the statistical analyses
Microalgal paste production of the diatom Chaetoceros calcitrans using electrolytic flocculation method at optimum culture conditions
No full textThe optimum culture conditions of the local strain Chaetoceros calcitrans were determined to improve biomass and reduce cost of production. Under outdoor culture conditions, higher cell density was attained when the cultures were enriched with Tungkang Marine Research Laboratory (TMRL) medium composed of cheap technical grade reagents and cultured at 25 g L−1 salinity. The cultures were lighted with two 40 W cool-white GE fluorescent tubes (24–35 μmol photon m−2 s−1). Using semi-continuous culture system under established optimum culture conditions, C. calcitrans can be re-cultured thrice and concentrated at each culture cycle using electrolytic flocculation method to produce 4.6 kg m−3 of diatom paste. The viability of concentrated C. calcitrans after 3 months of storage was comparable to live diatom cells. Simple preservation technique by low-temperature storage is convenient for storing algal concentrates for use as starter cultures and for feeding invertebrates. The paste costs USD 8.24 kg−1 inclusive of the assets and flocculation materials for culturing and harvesting the diatom, respectively. This study established the suitable conditions for mass culture of C. calcitrans and produced concentrated diatoms in paste form that is readily available for aquaculture hatcheries at a lower cost.This study was funded by the Aquaculture Department, Southeast Asian Fisheries Development Center (SEAFDEC/AQD) Code 5103-20T and Department of Science and Technology (DOST) under the auspices of the Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCAARRD). The methods of this study were based on the results of the research code NR-02-C2005T funded by SEAFDEC/AQD
