421-440 / 1693

    • Using mangroves for aquaculture - Why should we? 

      Primavera, Jurgenne ORCID (Western Indian Ocean Marine Science Association (WIOMSA), 2011)
      Although brackishwater ponds have been a major factor in mangrove loss in Southeast Asia where aquaculture is centuries-old, the “No Touch option” for mangroves is a luxury that most countries in the region cannot afford. So the question is not whether mangroves and aquaculture are compatible, but how best to integrate them so that mangrove services are maximized while some benefits from aquaculture remain? A review of “mangrove-friendly aquaculture” or MFA in Southeast Asia shows that while some technologies are traditional, others are government-driven (rather than research-based, to mitigate social conflict). MFA may be sited in subtidal waterways (e.g., seaweeds, bivalves) or the intertidal forest -- Hong Kong gei wai, Indonesian tambak tumpang sari, Vietnam mixed mangrove-shrimp farm systems and mangrove pens for mudcrab in Malaysia.
    • Dietary administration of dehydroepiandrosterone hormone influences sex differentiation of hybrid red tilapia (O. niloticus x O. mossambicus) larvae 

      Mohamed, Asaad H.; Traifalgar, Rex Ferdinand M.; Serrano, Augusto E., Jr.; Peralta, Jose P.; Pedroso, Fiona L. (Academic Journals, New York, 2012)
      Effects of a steroid hormone Dehydroepiandrosterone (DHEA) on sex differentiation of hybrid red Tilapia Oreochromis niloticus x O. mossambicus larvae were investigated. Three day-old tilapia larvae were fed diets supplemented with varying concentrations of DHEA (0, 20, 40, 80 and 160 mg kg-1 feed) for 24 days. A positive control group fed with diet containing 60 mg kg-1 of 17α-methyl testosterone was also included in the experimental run. Results indicate that among the DHEA treatment groups, larvae fed with 160 mg kg-1 DHEA showed the highest percentage of males that is comparable to the number of differentiated male fish observed in treatment group receiving the 17α-methyl testosterone as the positive control group. DHEA supplementation also improves weight gain and enhances feed conversion ratio. These findings suggest that DHEA can be used as a dietary supplement to induce masculinization and can improve the growth performance of tilapia larvae.
    • Sustaining aquaculture by developing human capacity and enhancing opportunities for women 

      Williams, Meryl J.; Agbayani, Renato F.; Bhujel, R.; Bondad-Reantaso, Melba G.; Brugère, C.; Choo, Poh Sze; Dhont, J.; Galmiche-Tejeda, A.; Ghulam, K.; Kusakabe, K.; Little, D.; Nandeesha, M. C.; Sorgeloos, Patrick; Weeratunge, N.; Williams, S.; Xu, P. (FAO; NACA, 2012)
      People are at the heart of sustaining aquaculture. Development of human capacity and gender, therefore, is an important human dimension. Human capacity development (HCD) was a major thrust of the 2000 Bangkok Declaration and Strategy, but gender was not addressed. The Food and Agriculture Organization of the United Nation's (FAO) Strategic Framework for Human Capacity Development (HCD) emphasized building human capacity in a coherent fashion at four levels - in individuals, organizations, sectors/networks and in the overall enabling environment. Although strategic HCD in aquaculture has not received attention, substantial HCD has occurred in aquaculture education and training. Aquaculture departments in universities, aquaculture research institutes, networks and professional societies all include training as central activities. Women are active participants in aquaculture supply chains, but a dearth of gender-disaggregated information hampers accurate understanding of their contribution. Research results and FAO National Aquaculture Sector Overview (NASO) fact sheets show that female participation rates vary by type and scale of enterprise and country. Women are frequently active in hatcheries and dominate fish processing plant labourers. Women's work in small-scale aquaculture frequently is unrecognized, under or unpaid. Most aquaculture development projects are not gender sensitive, and aquaculture success stories often do not report gender dimensions; projects can fail if their designs do not include gender. Lacking gender-disaggregated data on participation rates and trends in education, we conducted a preliminary survey of aquaculture tertiary institutes in Africa, Asia, Europe and North America. The percentage of female graduates in aquaculture increased considerably over the last four decades, from zero or low numbers in the 1970s to recent rates of around 30-60 percent; rates vary both by country and within countries. No data are available to track whether female graduates are entering successful careers in aquaculture. To accelerate HCD to meet the needs of aquaculture growth, commodity and theme priorities for HCD must be established. Educational institutions should cooperate and harmonize work programmes and overcome language barriers. Aquaculture education needs the best students and should help prepare them for rewarding careers. More social science content is needed in aquaculture curricula to groom graduates for management and leadership roles. The gender balance in aquaculture faculty could be improved by recruiting and retaining more women. Gender should be put firmly on the policy agenda and built into normative instruments, old and new, complemented by the collection of gender-disaggregated data for aquaculture supply chains. Women should be empowered through gender equity in access to financial, natural, training and market resources. Women in aquaculture should not be stereotyped as 'small-scale' and poor. Women are often hampered by systemic barriers such as lack of legal rights. Women should be encouraged to build their management, leadership and entrepreneural skills. In circumstances where rural men have migrated for work, small-scale aquaculture has proven a suitable livelihood option to reduce the pressure on women. Because postharvest processing and fish trade are feminized occupations, gender equity deserves special attention in fair trade and fish certification schemes. HCD and gender are receiving more attention in rehabilitation efforts to assist survivors from disease and natural disasters.
    • Ultrastructure of the anterior intestinal epithelia of the orange-spotted grouper Epinephelus coioides larvae under different feeding regimes 

      Primavera-Tirol, Y. H.; Coloso, R. M.; Quinitio, G. F.; Ordonio-Aguilar, R.; Laureta, L. V., Jr. (Springer Verlag, 2014)
      Enterocytes of the anterior to midsection of the intestine in grouper Epinephelus coioides larvae were compared among different treatments: unfed to the point-of-no-return (PNR), fed natural food only, and co-fed natural food and artificial diet. On day 3, the nutritional condition of unfed grouper larvae regressed with its reduced enterocyte heights which were further degraded on day 4, the PNR, when all the enterocytes were in advanced stages of apoptosis. The apoptosis appeared to be internally directed via the mitochondria. Among day 3 fed larvae, enterocyte heights of those fed artificial diet did not differ from those fed natural food only. Dietary phospholipid deficiency was indicated in larvae co-fed artificial diet on day 3 with an unusually large chylomicron opening into the inter-enterocyte space, and on days 6 and 33 by intestinal steatosis. On day 19, scant to absent lipid droplets in enterocytes of larvae disclosed heightened nutritional requirement preparatory to metamorphosis. As observed in unfed day 3 and premetamorphic day 19 E. coioides, larvae undergoing critical periods and starvation during development employ apoptosis to dispose of degenerated enterocytes that are phagocytosed by adjacent healthy enterocytes without causing inflammatory distress. Upon metamorphosis, grouper larval gut develops better immunity fitness with eosinophilic granule cells observed in the intestinal epithelia of day 33 larvae. Future studies on grouper larval nutrition may consider the appropriate dietary phospholipid levels and larval competence to biosynthesize highly unsaturated fatty acid from linoleic acid vis-à-vis the use of plant ingredients in artificial diet formulations. In vivo challenge tests may validate appropriate dietary nutrient supplementation and lead to better feed formulation, matching the varying energetic demands and digestive capacities of developing E. coioides larvae.
    • Apparent digestibility coefficient of nutrients from shrimp, mussel, diatom and seaweed by juvenile Holothuria scabra Jaeger 

      Orozco, Zenith Gaye Almeda; Sumbing, Joemel Gentelizo; Lebata-Ramos, Ma. Junemie Hazel ORCID; Watanabe, Satoshi (Wiley, 2014)
      The ability of Holothuria scabra to digest nutrients, such as organic matter (OM), protein and carbohydrate from animal and plant feed ingredients was investigated. Four test feeds prepared by mixing sand with single ingredients from animal sources (shrimp and mussel) and plant sources (diatom and seaweed) were fed to H. scabra to estimate apparent digestibility coefficient (ADC). The total assimilated nutrient (TAN) increased with ADC, whereas ingestion rate (IR) varied slightly among the feeds suggesting that ADC might be a good indicator of nutrient availability to H. scabra. The ADCOM of shrimp and mussel was significantly higher than that diatom and seaweed: 86.2%, 77.1%, 55.1% and 32.3% respectively. ADCprotein was similar for shrimp (88.7%), mussel (84.8%) and diatom (75.2%), but significantly lower in seaweed (34.4%). ADCcarbohydrate was similar in mussel (58.5%) and diatom (58.3%) as well as in seaweed (31.6) and shrimp (28.0%). ADCprotein was relatively higher than ADCcarbohydrate suggesting that H. scabra generally digests more protein than carbohydrate. Furthermore, results indicated that nutrients from animal-based feeds are more efficiently digested by H. scabra; thus, animal ingredients rich in easily digestible protein could potentially provide an efficiently balanced diet for H. scabra fed with diatom containing high easily digestible carbohydrate.
    • Paralytic shellfish poisoning toxin accumulation in shellfishes collected from various habitats in Murcielagos Bay, Philippines during harmful algal blooms occurrence 

      Narceda, Ronald Jefferson A.; Montojo, Ulysses M.; Eguia, Ma. Rowena R. ORCID; Sia Su, Glenn L. (American-Eurasian Network for Scientific Information (AENSI), 2014)
      This study aims to determine whether the habitat of bivalves plays an influence in the occurrence of tropical shellfish toxicity during toxic red tide bloom occurrences in Murcielagos Bay, Misamis Occidental, Philippines. Various shellfish species were collected during the occurrence of red tide blooms. The type of habitat and the shellfish toxicities were investigated. Likewise, the phytoplankton profile in the seawater column was assessed. Results of our study revealed that the occurrence of shellfish toxicities was habitat specific in spite of the fact that the causative organism Pyrodinium bahamense var. compressum was present in low concentrations in the sampling sites. Shellfish collected from sea grass, coralline area, and seafloor habitats were notably susceptible against the paralytic shellfish poisoning toxin contamination compared to those samples obtained from soil substrate. Continuous monitoring of areas that are affected with shellfish toxicity must be conducted so as to safeguard the general public’s welfare dependent on these resources.
    • Molecular cloning and localization of GABAA receptor-associated protein in the rotifer Brachionus plicatilis 

      Marcial, Helen S.; Suga, Koushirou; Kinoshita, Shigaheru; Kaneko, Gen; Hagiwara, Atsushi; Watabe, Shugo (Wiley-VCH Verlag, 2014)
      γ-Aminobutyric acid receptor type A-associated protein (GABARAP) and its homologs constitute a protein family found in many eukaryotes from yeast to human, and are known to be involved in intracellular membrane trafficking of GABAA receptors and autophagy. In this study, we cloned cDNA-encoding GABARAP from the monogonont rotifer Brachionus plicatilis and examined for its tissue distribution at the protein level in neonates, males and females. Using reverse transcription (RT)-PCR and rapid amplification of cDNA ends (RACE) techniques, we showed that like other GABARAPs, rotifer GABARAP was also composed of 117 amino acids and highly homologous to vertebrate GABARAP2 ortholog (74–76% identity). GABARAP was demonstrated with its specific antibody to be ubiquitously distributed, irrespective of neonates, males, and females, in the coronal area that covers brain and contains most mechano- and chemoreceptors. Rotifer GABARAP was also expressed in the mature eggs but not in immature eggs. Double immunostaining with mammalian anti-GABA γ receptor antibody showed that rotifer GABARAP co-localized with GABA receptor, suggesting the association of the two proteins. The presence of GABARAP in rotifer implies that it is highly conserved during evolution, and plays important roles in various biological processes.
    • Subtracted transcriptome profile of tiger shrimp (Penaeus monodon) that survived WSSV challenge 

      Maralit, Benedict A.; Ventolero, Minerva Fatimae H.; Maningas, Mary Beth B.; Amar, Edgar C. ORCID; Santos, Mudjekeewis D. (Hindawi Publishing Corporation, 2014)
      There is increased interest in the development of virus-resistant or improved shrimp stock because production is currently hindered by outbreaks and limited understanding of shrimp defense. Recent advancement now allows for high-throughput molecular studies on shrimp immunity. We used next-generation sequencing (NGS) coupled with suppression subtractive hybridization (SSH) to generate a transcriptome database of genes from tiger shrimp that survived White spot syndrome virus (WSSV) challenge. A total of 9,597 unique sequences were uploaded to NCBI Sequence Read Archive with accession number SRR577080. Sixty-five unique sequences, 6% of the total, were homologous to genes of Penaeus monodon. Genes that were initially related to bacterial infection and environmental stress such as 14-3-3 gene, heat shock protein 90, and calreticulin were also found including a few full-length gene sequences. Initial analysis of the expression of some genes was done. Hemocyanin, ferritin, and fortilin-binding protein exhibited differential expression between survivor and control tiger shrimps. Furthermore, candidate microsatellite markers for brood stock selection were mined and tested. Four trinucleotide and one dinucleotide microsatellites were successfully amplified. The study highlights the advantage of the NGS platform coupled with SSH in terms of gene discovery and marker generation.
    • Hydrolyzed tuna meat by-product supplement for juvenile red sea bream, Pagrus major, and its effect on growth, enzyme activity, plasma parameters, and apparent nutrient digestibility 

      Mamauag, Roger Edward ORCID; Ragaza, Janice Alano; Koshio, Shunsuke; Ishikawa, Manabu; Yokoyama, Saichiro (Society of Israeli Aquaculture and Marine Biotechnology (SIAMB), 2014)
      A growth experiment was conducted on juvenile red sea bream, Pagrus major to investigate the effect of the inclusion in fish diets, of tuna meat by-product hydrolysate which was processed through enzymatic hydrolysis using a commercially available enzyme, derived from Bacillus subtilis. Six experimental diets were formulated in the experiment. Three diets contained 50, 150 and 250 g/kg of TPM-H (tuna meat by-product hydrolysate), and two diets with the unprocessed TPM (tuna meat by-product) at an inclusion level of 50 and 250 g/kg. A control diet was formulated without any addition of the test ingredients. Treatment diets were fed ad libitum to juvenile fish with an initial average body weight of 0.81 ±0.13 g for 56 days. Results of the feeding trial suggest that the inclusion of TPM-H at 250 g/kg in fish diets improved body weight gain rate (3271.58%), feed intake (24.55 g/fish/56 days) and feed conversion efficiency (1.12) of the fish. Apparent nutrient digestibility of hydrolyzed tuna meat by-product improved compared to the unhydrolyzed ingredient. These results suggest that TPM processed as hydrolysates can be efficiently utilized by fish.
    • Ecological role and services of tropical mangrove ecosystems: A reassessment 

      Lee, Shing Yip; Primavera, Jurgenne ORCID; Dahdouh-Guebas, Farid; McKee, Karen; Bosire, Jared O.; Cannicci, Stefano; Diele, Karen; Fromard, Francois; Koedam, Nico; Marchand, Cyril; Mendelssohn, Irving; Mukherjee, Nibedita; Record, Sydne (Wiley, 2014)
      Aim To reassess the capacity of mangroves for ecosystem services in the light of recent data. Location Global mangrove ecosystems. Methods We review four long-standing roles of mangroves: (1) carbon dynamics – export or sink; (2) nursery role; (3) shoreline protection; (4) land-building capacity. The origins of pertinent hypotheses, current understanding and gaps in our knowledge are highlighted with reference to biogeographic, geographic and socio-economic influences. Results The role of mangroves as C sinks needs to be evaluated for a wide range of biogeographic regions and forest conditions. Mangrove C assimilation may be under-estimated because of flawed methodology and scanty data on key components of C dynamics. Peri-urban mangroves may be manipulated to provide local offsets for C emission. The nursery function of mangroves is not ubiquitous but varies with spatio-temporal accessibility. Connectivity and complementarity of mangroves and adjacent habitats enhance their nursery function through trophic relay and ontogenetic migrations. The effectiveness of mangroves for coastal protection depends on factors at landscape/geomorphic to community scales and local/species scales. Shifts in species due to climate change, forest degradation and loss of habitat connectivity may reduce the protective capacity of mangroves. Early views of mangroves as land builders (especially lateral expansion) were questionable. Evidence now indicates that mangroves, once established, directly influence vertical land development by enhancing sedimentation and/or by direct organic contributions to soil volume (peat formation) in some settings. Main conclusions Knowledge of thresholds, spatio-temporal scaling and variability due to geographic, biogeographic and socio-economic settings will improve the management of mangrove ecosystem services. Many drivers respond to global trends in climate change and local changes such as urbanization. While mangroves have traditionally been managed for subsistence, future governance models must involve partnerships between local custodians of mangroves and offsite beneficiaries of the services.
    • Poly-β-hydroxybutyrate (PHB) accumulating Bacillus spp. improve the survival, growth and robustness of Penaeus monodon (Fabricius, 1798) postlarvae 

      Laranja, Joseph Leopoldo ORCID; Ludevese-Pascual, Gladys ORCID; Amar, Edgar C. ORCID; Sorgeloos, Patrick; Bossier, Peter; De Schryver, Peter (Elsevier, 2014)
      Low larval survival resulting from suboptimal culture conditions and luminous vibriosis poses a major problem for the larviculture of penaeid shrimp. In this study, a poly-β-hydroxybutyrate (PHB) accumulating mixed bacterial culture (mBC; 48.5% PHB on cell dry weight) and two PHB accumulating bacterial isolates, Bacillus sp. JL47 (54.7% PHB on cell dry weight) and Bacillus sp. JL1 (45.5% PHB on cell dry weight), were obtained from a Philippine shrimp culture pond and investigated for their capacity to improve growth, survival and robustness of Penaeus monodon postlarvae (PL). Shrimp PL1 and shrimp PL30 were provided with the PHB containing bacterial cultures in the feed for 30 days followed by, respectively, a challenge with pathogenic Vibrio campbellii and exposure to a lethal dose of ammonia. Prior to the pathogenic challenge or ammonia stress, growth and survival were higher for shrimp receiving the PHB accumulating bacteria as compared to shrimp receiving diets without bacterial additions. After exposure to the pathogenic challenge the shrimp fed PHB accumulating bacteria showed a higher survival as compared to non-treated shrimp, suggesting an increase in robustness for the shrimp. Similar effects were observed when shrimp PL30 were provided with the PHB accumulating bacterial cultures during a challenge with pathogenic V. campbellii through the water. The survival of shrimp exposed to lethal ammonia stress showed no significant difference between PHB accumulating bacteria-fed shrimp and non-PHB treated shrimp. The data illustrate that bacilli capable of accumulating PHB can provide beneficial effects to P. monodon post-larvae during culture in terms of growth performance, survival and resistance against pathogenic infection and ammonia stress. Further investigations are required to verify the PHB effect of the bacterial cultures on the shrimp.
    • Interactive effects of vitamin C and E supplementation on growth performance, fatty acid composition and reduction of oxidative stress in juvenile Japanese flounder Paralichthys olivaceus fed dietary oxidized fish oil 

      Gao, Jian; Koshio, Shunsuke; Ishikawa, Manabu; Yokoyama, Saichiro; Mamauag, Roger Edward ORCID (Elsevier, 2014)
      A study was conducted to determine the interactive effects of vitamin C (VC) and E (VE) supplementation on growth, fatty acid composition and oxidative status of Japanese flounder juveniles. Fish (initial average body weight of 1.1 ± 0.1 g) in triplicate were fed five test diets for 60 days. Control diet contained fresh fish oil (FFO, 8.9 meq/kg) with 100 mg α-tocopherol (α-Toc) equivalents/kg of VE and 500 mg ascorbic acid (AsA) equivalents/kg of VC (FFO100E/500C). The other four diets contained oxidized fish oil (OFO, 167.8 meq/kg) with varying levels of VE (mg/kg) and VC (mg/kg) (OFO100E/500C, OFO200E/500C, OFO100E/1000C and OFO200E/1000C). Fish fed FFO100E/500C and OFO100E/500C had no differences in body weight gain (BWG). However, fish fed OFO200E/1000C diet had a significantly lower BWG than FFO100E/500C. Fish fed OFO200E/500C and OFO100E/1000C showed no differences in thiobarbituric acid-reactive substance values compared with FFO100E/500C. Increasing the levels of VC and VE supplementation increased liver AsA and α-Toc contents, respectively. Liver α-Toc content was significantly increased with incremental dietary VC levels, indicating a sparing effect of VC on liver α-Toc content of fish. Increasing the levels of dietary VC and VE supplementations decreased concentrations of 20:5n-3, 22:5n-3 and 22:6n-3 in fish liver. Fish fed OFO100E/500C and OFO200E/1000C diets showed higher oxidative stress condition than those fed FFO100E/500C. In conclusion, dietary VC and VE supplementation could maintain normal growth and health condition of juvenile Japanese flounder fed OFO. However, high doses of both vitamin supplements induced fish lipid peroxidation under oxidative stress condition.
    • Effects of human chorionic gonadotropin (hCG) and handling stress on spermiation of silver perch Leiopotherapon plumbeus (Kner, 1864) 

      Denusta, Pastor Jones ORCID; de Jesus-Ayson, Evelyn Grace T.; Laron, Manuel A.; Garcia, Luis Maria ORCID (Wiley, 2014)
      This study determined the effect of human chorionic gonadotropin (hCG) and handling stress on the spermiation and milt response of silver perch Leiopotherapon plumbeus based on the measurement of spermatocrit, sperm density, and milt production. Compared to saline-injected fish, the mean spermatocrit (or packed sperm) of hCG-treated fish was significantly lower at 18 h (47.9%) and 30 h (40.2%) post-injection while mean sperm density was significantly lower at 30 h post-injection (3.6 × 106 cells μl−1) but not at 18 h. At 18 h (1.8 μl g-BW−1) and 30 h (2.5 μl g-BW−1) post-injection, mean milt production of hCG-treated fish was significantly higher than in the saline group. Milt consistency was also thinner in the hCG-treated group. Mean sperm density of handled fish (18.0 × 106 cells μl−1) was significantly lower than control fish (23.4 × 106 cells μl−1). However, mean sperm density of handled plus saline-injected (16.2 × 106 cells μl−1) and handled plus hCG-treated fish (8.4 × 106 cells μl−1) was significantly lower than in the control goup. Having thicker milt consistency, mean spermatocrit and milt production of handled (77.5%; 1.1 μl g-BW−1, respectively) and handled plus saline-injected fish (75.4%; 1.1 μl g-BW−1, respectively) were not significantly different from the control fish (76.2%; 1.3 μl g-BW−1, respectively). Handled plus hCG-treated fish had the lowest mean sperm density (8.4 × 106 cells μl−1) and spermatocrit (54.7%), but had the highest mean milt production (5.5 μl g-BW−1) among the treatment groups. These results demonstrate that the hCG injection effectively induces spermiation and milt expression and that handling-related stress negatively affects such responses. The spermatocrit method may be used to assess the spermiation and milt response of silver perch.
    • Embryonic development of the Caridean prawn Macrobrachium mammillodactylus (Crustacea: Decapoda: Palaemonidae) 

      Cuvin-Aralar, Maria Lourdes A. (Taylor & Francis, 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.
    • Biomass yield of Isochrysis galbana (Parke; clone T-ISO) and growth of Brachionus rotundiformis (Tschugunoff) using continuous cultivation method 

      de la Peña, Milagros R. (College of Agriculture, University of the Philippines Los Baños, 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 (Brahionus 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.
    • Comparing profits from shrimp aquaculture with and without green-water technology in the Philippines 

      Bosma, Roel H.; Tendencia, Eleonor ORCID (Taylor & Francis, 2014)
      To reduce disease impact, Philippine farmers developed the green-water (GW) system, which has been spreading rapidly since 2008. In the most applied GW-system, the shrimp pond receives water from a reservoir stocked with tilapia. We collected financial data on GW and non-GW systems from farms having similar management and environmental context. All farms had more than one pond; the average pond area was < 1 ha, and total pond areas per farm ranged from 1.4 to 139 ha. The total variable and fixed costs per ha of shrimp pond were not different for GW and non-GW farms, but on GW farms the cost per kg of shrimp produced was lower. The latter was higher than the 2009 market price of 30 g shrimp for non-GW farms mainly. In GW farms the cost of seed was lower, and survival rates and individual shrimp weights at harvest were higher for an equally long culture period.
    • Community-based technology transfer in rural aquaculture: The case of mudcrab Scylla serrata nursery in ponds in northern Samar, central Philippines 

      Baticados, Didi B.; Agbayani, Renato F.; Quinitio, Emilia T. ORCID (Springer Verlag, 2014)
      Finding aquaculture development approaches to open up livelihood opportunities for the rural poor and in mainstreaming smallholder fish farmers to reduce poverty remain a challenge. This paper examines the community-based technology transfer mechanism of mudcrab nursery in ponds and its socioeconomic impacts on smallholder mudcrab growers in Northern Samar, Philippines. Results indicated that the technology is a viable enterprise done by a straight culture system method, which is the rearing of crablets from <1.0 to 4.0 cm for 42 days, or by-phases. However, technology adoption hinges on many factors like area ownership, farm distance from household, and market including the type of strategy needed to enhance technology uptake. Collaboration among research and development institutions and local partners is critical in training and empowering rural communities to adopt aquaculture technologies.
    • Improved resistance against White Spot Virus (WSV) infection in tiger shrimp, Penaeus monodon by combined supplementation of peptidoglycan and mannan oligosaccharide (MOS) 

      Apines-Amar, Mary Jane S.; Andrino, Karen Grace S.; Amar, Edgar C. ORCID; Cadiz, Rowena E.; Corre, Valeriano L., Jr. (Bioflux Society, 2014)
      An eight-week feeding trial was conducted to evaluate the effects of combined supplementation of peptidoglycan and mannan oligosaccharide (MOS) in tiger shrimp, Penaeus monodon. Tiger shrimp (0.29 ± 0.02 g) were fed diets supplemented with different levels of peptidoglycan + (MOS) as immunostimulants for six (6) and eight (8) weeks. Four (4) experimental diets were formulated to contain 0, 0.1, 0.2, and 0.4% peptidoglycan + MOS. The feeding trial was conducted in 250 L capacity concrete circular tanks (replicated four (4) times) with 20 shrimp per tank. Growth, survival, respiratory burst activity, total hemocyte count (THC), and in vivo resistance to WSV infection were evaluated. Weight gain of the shrimp was significantly higher in the immunostimulant-fed groups compared to the control. However, different levels of the immunostimulants did not differ in their effect on the the growth of the shrimp. On the other hand, respiratory burst activity and total haemocyte count (THC) were significantly higher in the group supplemented with 0.2% peptidoglycan + MOS than the rest of the treatments. Likewise, survival after infection with White Spot Virus (WSV) was significantly increased in the 0.2% peptidoglycan + MOS compared to the other groups. The present results demonstrated that using peptidoglycan and MOS together at 0.2% of the diet improves growth, activates immune responses such as respiratory burst activity and THC in P. monodon and give better protection to the shrimp against WSV infection.
    • Diet-tissue stable isotopic fractionation of tropical sea cucumber, Holothuria scabra 

      Watanabe, Satoshi; Kodama, Masashi; Sumbing, Joemel Gentelizo; Lebata-Ramos, Maria Junemie Hazel ORCID (Japan International Research Center for Agricultural Sciences (JIRCAS), 2013)
      To provide a basis for a stable carbon and nitrogen isotope ratio \(\mathsf{(\delta^{13}C / \delta^{15}N)}\) analysis to determine the assimilated organic matter in sea cucumber, Holothuria scabra, diet-tissue fractionations were experimentally determined by mono-feeding rearing with diatom. While δ15N fractionation of the whole body wall (2.4‰) was similar to the commonly accepted value (2.6 - 4‰), δ13C fractionation of the body wall (4.2‰) showed considerable discrepancy with the commonly accepted value (0 - 1‰) due to the high content (35% dry wt/wt) of calcareous spicules (CaCO3) in the body wall, which had significantly higher δ13C (-8.6‰) than the organic fractions. Computational elimination of spicules based upon spicule content and spicule δ13C reduced the δ13C fractionation of the body wall to 1.5‰, close to the common value. δ13C fractionation after spicule removal by acid decarbonation and subsequent rinsing (3.2‰) did not agree with the common value, and δ15N fractionation was significantly elevated by decarbonation. δ15N and δ13C fractionations of the intestine (1.5 and 2.2‰, respectively) did not agree with the common values. Since δ13C and δ15N of the feces did not differ significantly from those of the diet, feces may be used to determine ingested organic matter in the wild.
    • Spawning of tiger grouper Epinephelus fuscoguttatus and squaretail coralgrouper Plectropomus areolatus in sea cages and onshore tanks in Andaman and Nicobar Islands, India 

      Rimmer, M. A.; Thampisamraj, Y. C.; Jayagopal, P.; Thineshsanthar, D.; Damodar, P. N.; Toledo, J. D. (Elsevier, 2013)
      The broodstock of two grouper species, tiger grouper Epinephelus fuscoguttatus and squaretail coralgrouper Plectropomus areolatus, were maintained in sea cages near Rutland Island, Andaman and Nicobar Islands, India, and their spawning performance was monitored from June 2007 to December 2010. E. fuscoguttatus generally spawned monthly in association with the new moon phase, for 8–9 months each year. Each year, they underwent a 3- to 4-month refractory period between February and June then recommenced spawning in May–July. P. areolatus showed a different spawning pattern to E. fuscoguttatus, spawning for less than 6 months each year, also in association with the new moon, and demonstrating much longer refractory periods (up to 15 months) than E. fuscoguttatus. Analysis of temperature data from the sea cage site showed that water temperature was significantly lower during spawning events than during comparable non-spawning periods. We postulate that one factor inhibiting spawning is higher water temperatures exceeding the upper thermal inhibitory limit for both grouper species during the hotter months of the year. Selected broodstock fish of both species were also maintained in onshore tanks fitted with recirculating filtration systems, but the spawning performance of both grouper species in the onshore tanks was inferior to broodstock held in the sea cages. E. fuscoguttatus maintained in onshore tanks spawned during only 5 months of the 42-month study period, whereas E. fuscoguttatus held in the sea cages spawned during 29 months over the same time frame. P. areolatus held in onshore tanks over the same period did not spawn, whereas P. areolatus held in sea cages spawned during 16 months out of the 42-month study period.