Now showing items 2943-2962 of 3211

    • Book chapter

      Table of contents - Health Management in Aquaculture 

      GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.) - In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      The Tangalan story 

      RIY Adan - SEAFDEC Asian Aquaculture, 1999 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Tank culture of Gracilaria heteroclada (Zhang et Xia) 

      MRJ Luhan, J Tanaka & Y Aruga - Philippine Agricultural Scientist, 2003 - College of Agriculture and Central Experiment Station, University of the Philippines Los Baños
      Culture conditions in tanks were manipulated to improve the growth and agar quality of Gracilaria heteroclada Zhang et Xia. Specific growth rates during culture ranged from -0.51% to 1.40% and gel strength of agar from 439 to 2155 g cm-2. G. heteroclada at a stocking density of 2kg ton-1 and fertilized with ammonium chloride at 40 mg L-1 grew best when water was changed once a month and ammonium chloride was replenished at 20 mg L-1 after water change. When water was not changed, good growth was observed in plants supplied with 1 mg L-1 diammonium phosphate on the 3rd wk of culture.
    • Conference paper

      Targeting essential gene utilizing RNA interference to protect the ailing shrimp/prawn industry against WSSV 

      JMS Lazarte & MBB Maningas - In MRR Romana-Eguia, FD Parado-Estepa, ND Salayo & MJH Lebata-Ramos (Eds.), Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia: Challenges in Responsible Production … International Workshop on Resource Enhancement and Sustainable Aquaculture Practices in Southeast Asia 2014 (RESA), 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The white spot syndrome virus (WSSV) remains to be the most widespread and devastating infectious agent that has hit particularly the marine shrimp aquaculture industry worldwide. To date, there are no known effective strategies that can combat WSSV infection. This study aimed to elucidate host-pathogen interaction through the functional study of host - gene. Utilizing RNA Interference, the function of contig23 (c23) in the shrimp genome, identified to have high homology with WSSVORF-325, was determined. Three set-ups were prepared for treatment of c23-, GFP-dsRNA, and PBS using Macrobrachium rosenbergii freshwater prawns. Each treatment group was challenged with WSSV and survival rate was recorded. C23-, and GFP-dsRNA injected prawns showed a significant survival rate of 100%, in contrast to 20% of the PBS injected prawns at 10 days post-infection (dpi). Results showed that injection of c23- and GFP-dsRNA prior to challenge with WSSV, delayed and reduced mortality in contrast to PBS-treated prawns, which showed high mortality. Gene expression analysis showed silencing of both WSSV and c23 at day 3 post-WSSV challenge. This study proved that c23-dsRNA has a protective effect on WSSVchallenged prawns and highlights its involvement in the infectivity of WSSV in M. rosenbergii.
    • Article

      Taxonomy and phylogeny of Nephroselmis clavistella sp. nov. (Nephroselmidophyceae, Chlorophyta) 

      DG Faria, A Kato, MR de la Peña & S Suda - Journal of Phycology, 2011 - Wiley-Blackwell
      Nephroselmis clavistella D. G. Faria et S. Suda sp. nov. is collected from coastal sand samples from the eastern and western coasts of Okinawa-jima Island, Japan. The description of the cultured strains is based on light and electron microscopic observations. The cultured strains are phylogenetically analyzed based on 18S rDNA sequences. The cells are remarkably right–left flattened and appear round or ellipse when viewed from their right or left side, and are ∼5.0 μm in diameter. The posterior flagellum curved around the cell body at rest. A single, parietal, crescent chloroplast is yellowish green and contains one conspicuous eyespot in its anterior-ventral edge near the short flagellum base. A pyrenoid with one starch sheath is located dorsal of the chloroplast. The cells are divided by transverse binary cell division, as is common in other species of this genus. The cell body is covered with five types of scales, and among them four scale types are similar to Nephroselmis rotunda. The fifth scale type is a distinctive spiny and club-shaped stellate scale with 10 spines, four of the 10 spines extended ∼150 nm and each are slightly curved with a hook at the end, whereas six spines are club-shaped blunt ended. This scale morphology, an important taxonomic characteristic, has never been described before for the genus Nephroselmis. The cell’s morphology is distinctive from previously described Nephroselmis species, and its unique scale characteristics led us to name this newly proposed species “clavistella,” meaning club star.
    • Article

      Techniques on algae harvesting and preservation for use in culture and as larval food 

      OM Millamena, EJ Aujero & IG Borlongan - Aquacultural Engineering, 1990 - Elsevier
      A method of algae harvesting and preservation was developed. Test algal species consisted of two diatoms: Chaetoceros calcitrans and Skeletonema costatum, and two flagellates: Tetraselmis chui and Isochrysis galbana. Chemical flocculation using alum and lime were evaluated as methods of harvesting algae. Freezing and sun-drying were used as methods of preservation with viability tests done on frozen samples. The usefulness of sun-dried algae was evaluated through its ability to support survival of Penaeus menodon larvae. Results showed that alum and lime flocculation were effective for Chaetoceros, Tetraselmis and Skeletonema but ineffective for Isochrysis. Optimum pH for algae removal with alum was found to be 6.5. With lime, algae removals increased with pH and was optimum at pH 9.5. A simple freezing technique preserves the viability of algal concentrates for culture purposes. Good performance of sun-dried Chaetoceros and Tetraselnlis suggests that these algae may be used as larval feed for Penaens monodon alone or supplementarily to eliminate complete dependence on carefully-timed live algal production.
    • magazineArticle

      The technology for milkfish hatchery in Indonesia 

      RS Patadjai - SEAFDEC Asian Aquaculture, 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The culture of milkfish (Chanos chanos), which is the oldest fish cultured in Indonesia, has spread to almost all the provinces in the country. In order to answer the demand of milkfish fry, without decreasing production and wild fry supply, artificial fry production in big and small-scale hatcheries is being practiced. Details are given of the milkfish hatchery system, listing also the major criteria to be taken into account for site selection. Operation of the hatchery is described, outlining the following activities: broodstock rearing; hormone implantation; broodstock maintenance; egg production and harvest; and, larval rearing.
    • magazineArticle

      Technology for the community: SEAFDEC-designed artificial reefs 

      Southeast Asian Fisheries Development Center, Aquaculture Department - SEAFDEC Asian Aquaculture, 1995 - Aquaculture Department, Southeast Asian Fisheries Development Center
      An account is given of the fabrication and deployment of artificial reefs used in the SEAFDEC/AQD's Community Fishery Resource Management project, which focused on Malalison Island located in west Central Philippines. The project aimed to apply community-based techniques of fishery resource management through the collaboration of community organizations, biologists and social scientists. The 3 types of reefs (building blocks, concrete pipe culvert, and modified concrete pipe culvert) were deployed at Gui-ob reef covering an area of less than 1 ha.
    • Conference paper

      Technology transfer and information dissemination at SEAFDEC/AQD. 

      CT Villegas - In Aypa S. (Ed.), ASEAN-EEC Aquaculture Development and Coordination Programme (AADCP) Workshop Proceedings on Strategy for Technology Transfer in Aquaculture; 14-18 November 1994; Puerto Azul Beach Hotel, Cavite. AADCP Proc. 6, 1995 - ASEAN-EEC Aquaculture Development and Coordination Programme
    • Book chapter

      Technology transfer of aquaculture technologies: framework and strategies 

      RF Agbayani, N Sumagaysay-Chavoso & JD Toledo - In Handbook for Regional Training on Community-Based Aquaculture for Remote Rural Areas of Southeast Asia, 2008 - Southeast Asian Fisheries Development Center
    • Conference paper

      Technology Verification and Extension Program of SEAFDEC AQD 

      DD Baliao - In LMB Garcia (Ed.), Responsible Aquaculture Development in Southeast Asia. Proceedings of the Seminar-Workshop on Aquaculture Development … Southeast Asia organized by the SEAFDEC Aquaculture Department, 12-14 October 1999, Iloilo City, Philippines, 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Realizing the urgent need to package technologies generated through the years of R&D, the SEAFDEC Aquaculture Department (AQD) through the TEchnology Verification and Extension Section (TVES) launched in June 1996, a technology transfer and commercialization program to test aquaculture technologies in actual production systems. On-site trials were implemented to verify sustainability, social equitability, and profitability of aquaculture technologies. Going into real-life situations using aquaculture farms, TVES collaborated with fish farmers and other institutions in brining technology to the end-users to enhance widespread interest in aquaculture. This way, TVES can hasten adoption of these technologies and intensify information dissemination to the rest of the aquaculture industry. Once found viable and profitabe, extension manuals derived from verification studies are published, with the hope that AQD can contribute to the country s concern for increasing livelihood opportunities and food production from the aquaculture sector.
    • Article

      Temperature and size range for the transport of juvenile donkey's ear abalone Haliotis asinina Linne 

      SMA Buen-Ursua & G Ludevese - Aquaculture Research, 2011 - Blackwell Publishing
      Live transport of hatchery-produced juvenile donkey's ear abalone Haliotis asinina Linne was examined to evaluate the effect of transportation on the survival of juvenile abalone. Simulated transport experiments were conducted to determine the appropriate temperature using 5, 10 and 20 g L−1 of ice to air volume for 8 h and the appropriate size using two size groups (Size A, 15–20 mm, 0.5–1.3 g, and Size B, 30–35 mm, 5.3–8.5 g) up to 24-h out-of-water live transport. Survival was significantly higher (P<0.001) when 10 g L−1 of ice was used to decrease the temperature to the range of 17–23 °C. At this temperature, both size groups subjected to simulated transport for 8 and 10 h had 100% survival after 48 h, while mortality occurred in abalones subjected to 16 and 24 h of simulated transport. The Size B abalone subjected to 24 h of transport had significantly higher survival (64.4 ± 2.9%) (P<0.001) than the Size A abalone (5.5 ± 1.6%) after 48 h. Live juvenile abalone were successfully transported to the field applying the protocols developed in the lab experiment. This study serves as a guide for handling and shipping live juvenile abalone.
    • Article

      Temperature fluctuation, low salinity, water microflora: Risk factors for WSSV outbreaks in Penaeus monodon. 

      EA Tendencia & JAJ Verreth - The Israeli Journal of Aquaculture-Bamidgeh, 2011 - Society of Israeli Aquaculture and Marine Biotechnology
      White spot syndrome virus (WSSV) has been devastating the shrimp industry for almost a decade. This study compares water parameters, alkalinity, and microflora in three ponds on a farm on Negros Island (Philippines) during two production cycles where WSSV infection resulted in an outbreak in 2006 but not in 2005. The total bacterial count of the pond water in 2005 was about twice as high as in 2006. However, luminous bacterial counts were twice as high in 2006 than in 2005 and total presumptive Vibrio, as counted on Vibrio selective thiosulfate citrate bilesalt sucrose (TCBS) agar, was over ten times higher, with a greater percentage of green colonies. More green colonies might indicate a higher concentration of harmful Vibrio bacteria. Total alkalinity for both production cycles was within the normal range while temperature, salinity, pH, and dissolved oxygen varied and sometimes fell below or exceeded the acceptable range. In 2006, there were more instances during which the temperature fluctuated 3-4°C within the period of 07:00-17:00, and salinity more often dropped below 15 ppt. Our survey suggests that WSSV outbreak are triggered by water temperature fluctuations of 3-4°C, coupled with low salinity and a high presumptive Vibrio count
    • Article

      Temporal changes in innate immunity parameters, epinecidin gene expression, and mortality in orange-spotted grouper, Epinephelus coioides experimentally infected with a fish pathogen, Vibrio harveyi JML1 

      EC Amar, JP Faisan Jr., MJS Apines-Amar & RV Pakingking Jr. - Fish and Shellfish Immunology, 2017 - Elsevier
      Changes in innate immunity parameters and epinecidin mRNA transcript levels were examined to characterize the non-specific immune response of E. coioides to pathogenic V. harveyi JML1 isolated from affected cage-cultured fish. After fish had been injected with bacteria at a dose causing 30% mortality, blood and tissue samples were collected at 0, 6, 12, 24, 48, 72, 96, 120, and 240 h post-infection (hpi) for assessment of indices such as the oxidative burst (OB) and phagocytic index (PI) of head kidney cells, and lysozyme activity (LYS) and total immunoglobulin (Total Ig) levels of the plasma. The epinecidin mRNA transcript levels (EGE) from skin, gills, liver, kidney, and spleen tissues were also determined by gelbased RT-PCR. Lastly, daily mortality (DM), liver total bacterial load (TBC), and presumptive Vibrio count (TVC) were monitored up to 240 hpi. The results revealed that bacteria proliferated rapidly in fish tissue, reaching peak densities at 24 hpi for both TBC and TVC but was on a downward trend thereafter. The pattern in fish mortality closely correlated with TBC and TVC. Total Ig, OB, and PI in E. coioides were suppressed in the early part of infection when V. harveyi load was high but recovered and later increased as bacterial density declined. LYS and EGE were consistently high and their activities were not hampered by bacterial infection. The study demonstrated that V. harveyi JML1 interacts with E. coioides by transiently inhibiting some immune parameters resulting in mortalities. However, consistently high LYS, upregulated EGE, and resurgent PI, OB and Total Ig conferred resistance and subsequent recovery in the fish. The study provides new insights on the interaction between E. coioides and V. harveyi JML1 that can aid in formulating health management strategies for groupers. Further studies on prophylactic interventions to enhance the innate immune response in grouper during infection with V. harveyi JML1 are suggested.
    • Article

      Terrestrial leaf meals or freshwater aquatic fern as potential feed ingredients for farmed abalone Haliotis asinina (Linnaeus 1758) 

      OS Reyes & AC Fermin - Aquaculture Research, 2003 - Blackwell Publishing
      Three terrestrial leaf meals, Carica papaya, Leucaena leucocephala, Moringa oliefera and a freshwater aquatic fern, Azolla pinnata were evaluated as potential ingredients for farmed abalone diet. All diets were formulated to contain 27% crude protein, 13% of which was contributed by the various leaf meals. Fresh seaweed Gracilariopsis bailinae served as the control feed. Juvenile Haliotis asinina (mean body weight=13.4±1.6 g, mean shell length= 38.8±1.4 mm) were fed the diets at 2–3% of the body weight day–1. Seaweed was given at 30% of body weight day–1. After 120 days of feeding, abalone fed M. oliefera, A. pinnata-based diets, and fresh G. bailinae had significantly higher (P<0.01) specific growth rates (SGR%) than abalone fed the L. leucocephala-based diet. Abalone fed the M. oliefera-based diet had a better growth rate in terms of shell length (P<0.05) compared with those fed the L. leucocephala-based diet but not with those in other treatments. Furthermore, protein productive value (PPV) of H. asinina was significantly higher when fed the M. oliefera-based diet compared with all other treatments (P<0.002). Survival was generally high (80–100%) with no significant differences among treatments. Abalone fed the M. oliefera-based diet showed significantly higher carcass protein (70% dry weight) and lipid (5%) than the other treatments. Moringa oliefera leaf meal and freshwater aquatic fern (A. pinnata) are promising alternative feed ingredients for practical diet for farmed abalone as these are locally available year-round in the Philippines.
    • 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.
    • Article

      Test of size-specific mass selection for Nile tilapia, Oreochromis niloticus L., cage farming in the Philippines 

      ZU Basiao & RW Doyle - Aquaculture Research, 1999 - John Wiley and Sons
      One generation of mass selection based on the collimation procedure (early culling of large fry) was applied on Nile tilapia, Oreochromis niloticus L., in net cages set in Laguna de Bay, Philippines. The objective was to test the effectiveness of a low-cost, small-scale broodstock improvement procedure in this culture environment. Directional selection was performed in two steps after initial removal of large fry at 21 days. Selection of parents and testing of the offspring were also conducted in hapa net cages set up in Laguna de Bay. The selection resulted in a significant positive response of 3% relative to the control, which represents a projected 34% gain over 5 years in Laguna cage culture. The realized heritability is approximately 16%.
    • Article

      Testicular histology and serum steroid hormone profiles in hatchery-bred catfish Clarias macrocephalus (Gunther) during an annual reproductive cycle 

      JD Tan-Fermin, T Miura, H Ueda, S Adachi & K Yamauchi - Fisheries Science, 1997 - Japanese Society of Fisheries Science
      Testicular development, gonadosomatic index (GSI), and related steroid hormones (testosterone or T, 11-ketotestosterone or 11-KT, 17α, 20β-dihydroxy-4-pregnen-3-one or DHP) in serum were monitored during an annual reproductive cycle in tank-reared, hatchery-bred male catfish Clarias macrocephalus to established the season optimum for its artificial propagation. GSI values were highest in June (0.80%), and lowest in December, February, April (0.36%). At most times of the year, lobules in the testis and seminal vesicles were mostly lined with spermatogonia B (SGb) and spermatocytes (SC) and few spermatogonia A (SGa); spermatids (SD) and spermatozoa (SZ) were the least and most abundant of the spermatogenic cells, respectively. In January however, almost equal counts of SGa, SGb and SC were observed, as well as a significant increase in the percentage of SD and corresponding decrease in SZ. Serum 11-KT fluctuated at high levels, with the lowest level in January (159.42 ng/ml), and peak in September (434.72 ng / ml). Serum T levels ranged from 15-25 ng/ml, and were not markedly different throughout the annual cycle. Serum DHP levels were extremely low in January-May, and reached maximum levels in July (0.18 ng/ ml). Seasonal changes in the percentage of spermatogenic cells, GSI and serum steroid hormone profiles showed that captive, hatchery-bred male C. macrocephalus have a continuous reproductive cycle. Although milt release was not observed, males can readily be used as source of milt for artificial propagation at any time of the annual cycle, except in January.
    • Conference paper

      Thailand's concerns in endangered species and stock enhancement 

      M Chaengkij - In JH Primavera, ET Quinitio & MRR Eguia (Eds.), Proceedings of the Regional Technical Consultation on Stock Enhancement for Threatened Species of International Concern, Iloilo City, Philippines, 13-15 July 2005, 2006 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Conference paper

      Thailand: mangrove-friendly shrimp farming 

      S Tanan & A Tansutapanich - In JH Primavera, LMB Garcia, MT Castaños & MB Surtida (Eds.), Mangrove-Friendly Aquaculture : Proceedings of the Workshop on Mangrove-Friendly Aquaculture organized by the SEAFDEC Aquaculture Department, January 11-15, 1999, Iloilo City, Philippines, 2000 - Southeast Asian Fisheries Development Center, Aquaculture Department