Southeast Asian Fisheries Development Center, Aquaculture Department Institutional Repository (SAIR) is the official digital repository of scholarly and research information of the department. This is to enable the effective dissemination of AQD researchers' in-house and external publications for free and online. The repository uses DSpace, an open source software, developed at Massachusetts Institute of Technology (MIT) Libraries. It is an Open Archives Initiative (OAI)-compliant.

Initially, the repository shall contain preprints, full-texts or abstracts of journal articles, books and conference proceedings written by SEAFDEC/AQD scientists and researchers. The aim is to promote these publications especially those published in international peer-reviewed journals and generate higher citation through increased visibility.

It will also provide free access to all in-house publications of SEAFDEC/AQD. Full-text digitized copies of fishfarmer-friendly materials like books, handbooks, policy guidebooks, conference proceedings, extension manuals, institutional reports, annual reports (AQD Highlights), and newsletters (SEAFDEC Asian Aquaculture, Aqua Farm News, AquaDept News and AQD Matters) can be retrieved and downloaded.

In the future, SAIR will expand its collection to include images, presentations, audios, and videos among others.

The objectives of the repository are to: (1) to provide reliable means for SEAFDEC/AQD researchers to store, preserve and share their research outputs and (2) to provide easy access and increase the visibility of SEAFDEC/AQD scientific publications

SAIR also aims to encourage SEAFDEC/AQD researchers for self-archiving and submitting pre-prints from which metadata will be screened and approved by the library staff.

Select a community to browse its collections.

  • Article

    Female-specific SNP markers provide insights into a WZ/ZZ sex determination system for mud crabs Scylla paramamosain, S. tranquebarica and S. serrata with a rapid method for genetic sex identification 

    Mud crabs, Scylla spp., are commercially important large-size marine crustaceans in the Indo-West Pacific region. As females have the higher growth rate and economic value, the production of all female stocks is extremely essential in aquaculture. However, the sex determination mechanism is still unclear. Development of sex-specific genetic markers based on next-generation sequencing proved to be an effective tool for discovering sex determination system in various animals.
  • Article

    Improved survival, prey selectivity and diel feeding cycle of silver therapon Leiopotherapon plumbeus (Perciformes: Terapontidae) larvae reared in tanks with substrate 

    FA Aya, VSN Nillasca, MJP Sayco & LMB Garcia - Ichthyological Research, 2018 - Springer Verlag
    Physical substrates in the rearing environment can influence the early survival and feeding patterns of captive-reared fish. In this study, we determined whether substrates affect the survival and growth of hatchery-reared silver therapon Leiopotherapon plumbeus larvae as well as examined their prey selectivity and diel feeding cycle. Newly hatched larvae [1.92 mm total length (TL)] were reared for 40 days in triplicate 4 m3 tanks with or without tropical almond Terminalia catappa leaves as substrate. Prey selectivity of larvae reared in tanks with substrate for 35 days from the yolk-sac stage was measured by the Chesson’s selectivity index (?i). Diel feeding cycle of 3-4 days post-hatch (dph) silver therapon larvae reared in tanks exposed to natural light cycle and fed wild zooplankton was also studied. Larvae reared in tanks with substrate had significantly higher survivorship (48.44?±?7.85%) than those reared in tanks without substrate (26.73?±?1.60%). However, total length, specific growth rate and body weight of silver therapon larvae from tanks with or without substrate were not significantly different. Silver therapon larvae are generalist predator, demonstrating a degree of prey selectivity in some prey items during early ontogeny. Prey selectivity of silver therapon larvae varied during larval ontogeny, with higher Chesson’s selectivity index for copepod nauplii among the smaller fish larvae (2–5 dph; 2.94–5.17 mm TL), cladocerans (Moina micrura and Bosmina coregoni) among intermediate (6–11 dph; 5.72–9.60 mm TL), and ostracod, cladoceran and insect larvae among larger fish (12–35 dph; 10.28–20.96 mm TL). Larvae showed a diel feeding cycle where they actively fed during daylight hours, with a peak in the late afternoon, and reached a minimum at dark. Together, these findings advance our understanding of the feeding predatory behavior and efficiency of silver therapon larvae and preference for tanks with substrate that improve their survival.
  • Article

    Gonadal response of juvenile protogynous grouper (Epinephelus fuscoguttatus) to long term recombinant follicle-stimulating hormone administration 

    P Palma, J Nocillado, J Superio, EGdJ Ayson, F Ayson, I Bar & A Elizur - Biology of Reproduction, 2018 - Oxford University Press
    The role of follicle stimulating hormone (FSH) in the gonadal development of protogynous hermaphroditic grouper (E. fuscoguttatus) was investigated. Recombinant giant grouper (E. lanceolatus) FSH (rggFSH) was produced in yeast. Its receptor binding capacity and steroidogenic potency were confirmed in vitro. Weekly injections of rggFSH to juvenile tiger grouper for 8 weeks (100 μg/kg body weight, BW) resulted in significantly larger and more advanced oocytes (cortical alveolar stage vs. primary growth stage in control). Sustained treatment with rggFSH (20 to 38 weeks at 200 μg/kg BW) resulted in significant reduction in gonad size, degeneration of oocytes and proliferation of spermatogonial cells, indicative of female to male sex change. Gene expression analysis showed that, while initiating female to male sex change, the rggFSH significantly suppressed the steroidogenic genes cyp11b, cyp19a1a and foxl2 which restrained the endogenous production of sex steroid hormones thus prevented the differentiation of spermatogonial cells. Expression profile of sex markers dmrt1, amh, figla and bmp15 suggests that the observed sex change was restricted at the initiation stage. Based on these results, we propose that the process of female to male sex change in the protogynous grouper is initiated by FSH, rather than sex steroids and likely involves steroid-independent pathway. The cortical alveolar stage in oocyte development is the critical point after which FSH-induced sex change is possible in grouper.
  • Article

    Immunization regimen in Asian sea bass (Lates calcarifer) broodfish: A practical strategy to control vertical transmission of nervous necrosis virus during seed production 

    R Pakingking Jr., EG de Jesus-Ayson, O Reyes & NB Bautista - Vaccine, 2018 - Elsevier
    Outbreaks 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.
  • Article

    Microalgal paste production of the diatom Chaetoceros calcitrans using electrolytic flocculation method at optimum culture conditions 

    MR de la Peña, AV Franco, HP Igcasan Jr., MDGN Arnaldo, RM Piloton, SS Garibay & VT Balinas - Aquaculture International, 2018 - Springer Verlag
    The 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.

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