Southeast Asian Fisheries Development Center

Tigbauan, Philippines

Southeast Asian Fisheries Development Center

Tigbauan, Philippines
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Luhan M.R.J.,Southeast Asian Fisheries Development Center | Mateo J.P.,Southeast Asian Fisheries Development Center
Journal of Applied Phycology | Year: 2017

Micropropagation has proven to be a reliable method to mass produce certain crops. This method also has been applied in macroalgae to produce clones for seaweed farming. Protocols for callus production and shoot regeneration from protoplasts have been established for some seaweed species like Kappaphycus alvarezii. Cells and larger tissues, whether in solid or suspension medium, have been used to propagate clones which were later tested for suitability for farming. Although clonal production was successful, the long duration of culture in vitro limits the production process making the growing of Kappaphycus in vitro an expensive technique to produce clones. In this study, K. alvarezii was grown in vitro to develop a more efficient protocol for the production of clones. Small sections of Kappaphycus were grown in suspension for 1 month under the same temperature, light, and salinity. The type of media, source of explants, length of explants, and stocking density that resulted in the highest growth rate and survival rate were determined. Growth rate of K. alvarezii is significantly higher in media with inorganic nitrogen added than in Grund medium or Ascophyllum nodosum medium only. The appearance of shoot primordia as early as 5 days was observed in media with higher nitrogen concentration. Growth rates of explants approximately 3 and 5 mm are significantly higher than 10 mm sections. Shoots develop significantly faster in explants from tips than sections from older branches. Growth rate of K. alvarezii grown at 0.5, 0.75, 1, 1.25 s 10 mL−1 of medium is not significantly different. This protocol could significantly reduce the (1) time of culture and (2) cost of plantlets production by not using plant growth regulators and formulated media in vitro. Nursery reared plantlets/propagules for farming would be affordable to the stakeholders for sustainability of seaweed production. © 2017 Springer Science+Business Media Dordrecht

Amar E.C.,Southeast Asian Fisheries Development Center | Apines-Amar M.J.S.,University of the Philippines in the Visayas
Fish and Shellfish Immunology | Year: 2017

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 gel-based 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. © 2017 Elsevier Ltd

De La Pena M.R.,Southeast Asian Fisheries Development Center
Philippine Agricultural Scientist | Year: 2014

Batch culture of Isochrysis galbana clone T-ISO is difficult due to its unstable biomass production; hence, the effect of continuous cultivation at different dilution rates was investigated to compare its productivity with that of batch culture. Significantly higher total algal cell yield was attained in continuous cultures (1.70 × 108 and 1.03 × 108 cells L-1 at 0.60 d-1 and 0.30 d-1 dilution rates, respectively) compared with batch culture (0.16 × 108 cells L-1); the batch culture did not receive any inflow of nutrients. The amount of protein per cell was similar in both batch and continuous cultures at 0.60 d-1 dilution rate after 24 h and 5 d in both culture systems. Chlorophyll a yield was not affected by dilution rate but decreased as the culture aged. The dry weight yield was also similar in both batch and continuous cultures. The higher nitrate concentration supplemented in the batch culture resulted in higher cell density and elevated protein content of the alga. Rotifer (Brachionus rotundiformis) cultures that received inflow of nutrients from the algal tanks had significantly higher (P<0.05) peak population count (28 and 33 individuals mL-1 at 0.30 and 0.60 d-1 dilution rates, respectively) compared with rotifer cultures that did not receive an inflow of food (18.22 individuals mL-1). The higher biomass yield of T-ISO using continuous cultivation method can increase the population growth of rotifer under tropical conditions. Copyright © 2017 The Philippine Agricultural Scientist.

Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: KBBE.2011.1.4-07 | Award Amount: 1.06M | Year: 2012

Aquaculture is widely considered as important for enhancing food security, alleviating poverty and improving nutrition. However, little information is available concerning the direct and indirect impacts of aquaculture on food security and poverty alleviation in most developing countries and LIFDCs. Strengthening the knowledge base surrounding aquaculture and food and nutrition security through this project will provide the evidence upon which sound resource allocation and strategies can be based, and subsequently plan, implement and coordinate efficiently development and research programmes supporting the sustainable expansion of aquaculture and increasing its impact to food security and poverty alleviation. The project is to be implemented by 18 partners in 11 selected LIFDCs, 3 EU partners, and 3 international organizations. The project will strengthen the knowledge base on food security and poverty and develop new methodologies or more rigorous methodologies to quantify the contribution of aquaculture in combating hunger and poverty in developing countries and LIFDCs. This will endeavour to better understand aquacultures contribution to human development. Project partner countries were selected based on varied human development conditions and national level efforts in including aquaculture for improving national food security and alleviating poverty. They represent all major aquaculture regions and ICPCs where aquaculture has major contributions to national economy involve high numbers of small-scale aquaculture farms, and with high international trade of fish and fishery products. The results of the project will be brought to the attention of countries and development partners, particularly the EU, and outputs will help LIFDCs and various development partners to improve efficiency and coordination in development initiatives focused on aquaculture as a means of promoting food security and poverty alleviation.

Bautista-Teruel M.N.,Southeast Asian Fisheries Development Center | Koshio S.S.,Kagoshima University | Ishikawa M.,Kagoshima University
Aquaculture | Year: 2011

Experiments on diet development and evaluation for juvenile abalone, Haliotis asinina focusing on lipid and essential fatty acid (EFA) levels were conducted. Six isonitrogenous diets were formulated in Experiment 1 (E1) to contain 27% protein with lipid levels at 0, 2, 4, 6, 8, and 10%. Experiment 2 (E2) (EFA levels), used the optimum lipid level (3.59%) in E1 with EFA supplementation of 0.0, 0.2, 0.4, 0.8, and 1.6%. Abalone juveniles [mean initial weight and shell length of 0.60 ± 0.07. g and 14.70 ± 0.12. mm (E1)], [0.60 ± 0.16. g and 15.30 ± 0.73. mm (E2)] respectively, were fed these diets at 2-5% body weight in 3 replicates. Feeding trials in 90. days/experiment evaluated growth, survival, feed conversion ratio (FCR) and fatty acid composition in abalone tissues. Results showed significantly higher growth rates (ANOVA P < 0.05) with abalone fed diets with lipid levels of 2.2%, 3.6%, and 6.1% compared with those containing lipid levels of 7.6% and 9.8%. Abalone fed the lipid-free diet showed significantly the lowest growth rate among treatments. Break point analysis as a function of growth, showed optimum lipid requirement at 3.59%. Survival was high at 95-99% in both experiments. FCR values for D3 and D4 were significantly better compared to D2, D5 and D6 (E1) while no significant differences were found for D2-D6 for E2. Abalone body lipid increased with corresponding increase in dietary lipid. Addition of 18:2n-6, 18:3n-3, and n-3 HUFA showed significant improvement in weight gains up to 1.6% supplementation. Fatty acid composition of the lipid samples reflected those of the diets. Total lipid of abalone fed the lipid-free diet showed higher monoenes. Addition of EFA resulted in an increase in both n-3 and n-6 fatty acids. Lipid incorporation at 3.6% using a 1:1 ratio of CLO and SBO with EFA supplementation (1.6%) is best in juvenile abalone diet formulation. © 2010 Elsevier B.V.

Celino F.T.,Southeast Asian Fisheries Development Center | Hilomen-Garcia G.V.,Southeast Asian Fisheries Development Center | del Norte-Campos A.G.C.,University of the Philippines in the Visayas
Aquaculture Research | Year: 2012

This study examined the feeding selectivity of Hippocampus kuda juveniles under captive conditions and evaluates different food organisms that could be used to improve hatchery-rearing of this species. Newly born H. kuda were reared for 10 days in 60-L capacity tanks and fed rotifers (Brachionus rotundiformis), zooplankton (mostly Pseudodiaptomus annandalei and Acartia tsuensis) alone or both food sources. The size and amount of food ingested increased as seahorses grew. Selective feeding of seahorses appeared to change as they develop, preferring copepod adults over nauplii and rotifers. A. tsuensis was highly selected by juveniles over P. annandalei. Specific growth rate in terms of body weight (SGR-BW, 15% day-1) was the highest and mortality rate (9% at day 10) the lowest in seahorses fed a mixed food sources. Slowest growth rate (0.3% day-1) and highest mortality rate (60% at day 7) were observed in seahorses fed rotifers alone. These results indicate that copepods are suitable food for seahorse juveniles, but a mixture of food organisms in the rearing tank environment enhances survivorship and growth of H. kuda, thus potentially providing a source of cultured rather than wild specimens for characterizing the life history of this threatened species. © 2011 Blackwell Publishing Ltd.

Cuvin-Aralar M.L.A.,Southeast Asian Fisheries Development Center
Lakes and Reservoirs: Research and Management | Year: 2016

Laguna de Bay is the largest inland water body in the Philippines, being used predominantly for aquaculture and open water fisheries. Aquaculture in the lake began decades ago, with many changes in the lake ecosystem having occurred since that time. Most dominant species for fish culture are introduced species. Other invasive species were also introduced to the lake as escapees from land-based aquaculture facilities. This study was conducted to monitor fish diversity in two adjacent, but distinctly different, sites in the lake, namely an open fishery area (OFS), with no adjacent aquaculture structures, and an aquaculture site (AQS), with cages for the culture of various commodities. Fish traps were installed at both sites, with the traps being sampled at least every 2 weeks from April 2013 to February 2015. The results of pairwise t-tests indicated significantly higher Shannon-Wiener diversity index (H′), evenness (J′), Simpson's similarity index (D) and species richness (s) in OFS than in AQS. In terms of total catch per day, significantly greater fish biomass were obtained from AQS than from OFS. Introduced aquaculture species had a mean dominance of 83% and 47% in AQS and OFS, respectively. However, invasive species introduced from the ornamental fish trade exhibited a mean relative dominance of 10.3% in AQS and 13.5% in OFS. The relative dominance of native species was also significantly higher in OFS (41%) than in AQS (6.5%). The results of this study demonstrated the adverse impacts of aquaculture in regard to the species diversity of fish in localized areas in Laguna de Bay. The dependency of aquaculture on introduced fish species adversely impacted the natural fish population in the lake. Focusing on the culture of commercially important local species for aquaculture, rather than introduced species, will improve fish production of inland waters without accompanying adverse impacts on biodiversity. © 2016 John Wiley & Sons Australia, Ltd.

Quinitio E.T.,Southeast Asian Fisheries Development Center | Estepa F.D.P.,Southeast Asian Fisheries Development Center
Aquaculture | Year: 2011

The effects of removing or trimming the chelipeds at various molt stages on regeneration, molt interval (MI) and specific growth rate (SGR) were determined in mud crab Scylla serrata. These strategies in combination with provision of shelters and food were tested in relation to survival and growth.Hatchery-reared S. serrata juveniles (1.3-2.2. g body weight) in the postmolt, intermolt, and premolt stages were subjected to autotomy of two chelipeds, and trimming of dactylus and pollex. Intact crabs served as the control group. Interval from stocking to first molt was significantly longer in crabs autotomized at intermolt or premolt than in trimmed or intact crabs, but was similar to intact crabs when autotomy was done at postmolt. However, MI from first to second molts was longer compared to intact crabs when chelipeds were removed or trimmed at premolt.After the first molt, autotomy and not trimming caused significant decrease in SGR. The SGRs at the end of the test were similar to intact crabs (postmolt: 7.90 ± 0.39, intermolt: 5.64 ± 0.50) when trimming of chelipeds was done at postmolt (8.01 ± 0.75) or intermolt (4.38 ± 0.40). However, SGR was lower when premolt crabs were subjected to autotomy (4.11 ± 0.67) and trimming (5.29 ± 1.40) than when chelipeds were intact (9.45 ± 0.47).A two-factor experiment was conducted in the second phase where intermolt crabs with autotomized or trimmed chelipeds (factor A) were either fed or starved but provided with shelters or fed but without shelters (factor B). After 10. days, higher survival was obtained in crabs with autotomized (95.55 ± 2.94%) or trimmed chelipeds (93.33 ± 3.33%) than in intact crabs (73.33 ± 6.67%). Survival was not affected by factor B, but higher final mean body weights were attained in fed crabs with (0.78 ± 0.04. g) or without shelters (0.74 ± 0.04. g) than unfed ones (0.48 ± 0.04. g). A third experiment was conducted to verify these results. Crabs with trimmed or intact chelipeds were either fed or unfed. No shelters were provided. Crabs with trimmed chelipeds (88.57 ± 0%) had higher survival than intact crabs (59.76 ± 7.56%) regardless of whether they were fed or starved; and fed crabs (0.82 ± 0.04. g) had higher mean body weight than unfed crabs (0.61 ± 0.07. g) regardless of whether chelipeds were intact or trimmed. These results indicate that trimming or total removal of chelipeds are effective strategies in reducing cannibalism. © 2011 Elsevier B.V.

Erazo-Pagador G.,Southeast Asian Fisheries Development Center
Journal of Shellfish Research | Year: 2010

This paper describes the first screening in the Philippines of slipper-cupped oysters (Crassostrea iredalei) for the presence of parasites. Slipper-cupped oysters were sampled at 2 sites in Ivisan, Capiz, from September to December 2007. Macroscopical and histological analyses were carried out in oyster tissues. Histological examination showed gregarine protozoan Nematopsis sp. as the most prevalent parasite (71.33% and 65.0%) at 2 sites with a moderate intensity of infection. Tylocephalum sp. cestode was found in the connective tissue around the digestive gland, with a prevalence of 60% and 52.3% in 2 sites, with a moderate intensity of infection. Digenean trematodes had a 37.80% prevalence at site 1 and a 22.45% prevalence at site 2. Ciliates were also observed with a prevalence of 18.75% (site 1) and 13% (site 2). The observed infection of oysters had no apparent effect on oyster production at these sites maybe due to low infestation levels or to the fact that the parasites have no pathological effect.

Cuvin-Aralar M.L.A.,Southeast Asian Fisheries Development Center
Invertebrate Reproduction and Development | Year: 2014

The freshwater knob-tooth prawn Macrobrachium mammillodactylus is a commercially exploited species in the Philippines. To study the biology of this species, broodstock from the wild was collected, transported to the laboratory and kept in pairs in indoor polyethylene tanks for breeding. Eggs from berried females were sampled to follow the stages of embryonic development until hatching to zoea larva. It took 18.0 ± 2.1 days for the eggs to hatch at ambient water temperature between 25 and 28 °C. The morphological landmarks of development at the different stages (pre-cleavage, cleavage, blastula, pre-nauplius, post-nauplius and pre-hatching) of the live embryos are described. Incremental percentage staging was adopted from 0% at fertilization to 100% at hatching and were matched with corresponding morphological development. Egg volume increased significantly toward the mid-to-later stages of development. The eye index also showed a significant increase as the egg developed. The colour of the egg mass changed from light olive green to grey as the eggs progressed in development. The general pattern of development was comparable to other members of the genus Macrobrachium. © 2014 Taylor and Francis.

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