Southeast Asian Fisheries Development Center
Southeast Asian Fisheries Development Center, Aquaculture Department Institutional Repository (SEAFDEC/AQD Institutional Repository )Not a member yet
4215 research outputs found
Sort by
Growth performance, production and economic viability of Indian white shrimp (Penaeus indicus H. Milne Edwards) fed with varying dietary protein levels
No full textThe growth efficiency, productivity and economic viability of Indian white shrimp (Penaeus indicus) fed with diet containing 40% (CPhigh) and 34% (CPlow) crude protein (CP) levels were determined in a 90-day grow-out culture trial. Growth parameters including average body weight (ABW), specific growth rate (SGR), survival and feed conversion ratio (FCR) were not statistically different. CPlow had lower overall shrimp production (797.53 kg/ha, DOC 90), but was not significantly different from CPhigh (843.78 kg/ha, DOC 90). The mean values for the water parameters of both treatments, such as DO, pH, salinity, temperature, TAN, NO2-N, NO3-N and PO4-P, also showed no significant differences. However, the TAN values of CPhigh were consistently higher from day of culture (DOC) 63 and increased significantly (p = .048) at DOC 90. Furthermore, the total bacterial and Vibrio counts in both treatments were not significant throughout the culture period. The economic analysis revealed that CPlow obtained higher net profits (6093 USD/ha/year), return on investment (72%) and discounted benefit–cost ratio (1.73). The current study found that feeding a low protein diet to P. indicus is economically viable and profitable and results in improved growth efficiency and productivity while also improving water quality and lowering nitrogen discharge.This study was supported by Aquaculture Department, Southeast Asian Fisheries Development Center (DP-02-C2017T)
Evaluation of dietary fermented tuna by-product meal as partial replacement for unprocessed tuna by-product meal in fishmeal-based diets for juvenile olive flounder Paralichthys olivaceus
No full textThis study examined the effects of feeding fermented tuna by-product (FTBP) on the growth, non-specific immune response, liver and intestinal morphology, and disease resistance of olive flounder Paralichthys olivaceus. Olive flounders (n = 20; 2 g) were randomly assigned into four dietary groups in triplicates. Fish were fed four test diets (50% crude protein; 10% crude lipid) for 10 weeks in which unprocessed tuna by-product (TBP) meal was replaced (on a protein basis) with 0% (FTBP0 as the control diet), 15% (FTBP15), 30% (FTBP30), and 60% (FTBP60) of FTBP protein. Results showed that growth performance, blood parameters, and proximate composition were not influenced by FTBP inclusion. Non-specific immune parameters such as superoxide dismutase activity in the FTBP30 and FTBP60 groups were significantly higher than in the FTBP15 and the control groups, whereas lysozyme and myeloperoxidase activities were not different. Liver histopathology revealed normal architecture in groups fed FTBP0 and FTBP15 diets although mild alterations were noted in the FTBP30- and FTBP60-fed groups. Intestinal villi height and muscular thickness were not significantly altered with FTBP inclusion. Moreover, higher cumulative survival rate was observed in the FTBP60-fed group than fish fed with the other diets following the 13-day challenge with E. tarda. Together, these results demonstrate that fermented tuna by-product meal could be included at 60% in olive flounder diets.This study was supported by the National Research Foundation of Korea through the Framework of International Cooperation Program (NRF-2016K2A9A1A09913758). The study was done as part of the Postdoctoral Research Fellowship of F. A. A
The synergistic impacts of anthropogenic stressors and COVID-19 on aquaculture: A current global perspective
Get PDFSupplemental materialThe rapid, global spread of COVID-19, and the measures intended to limit or slow its propagation, are having major impacts on diverse sectors of society. Notably, these impacts are occurring in the context of other anthropogenic-driven threats including global climate change. Both anthropogenic stressors and the COVID-19 pandemic represent significant economic challenges to aquaculture systems across the globe, threatening the supply chain of one of the most important sources of animal protein, with potential disproportionate impacts on vulnerable communities. A web survey was conducted in 47 countries in the midst of the COVID-19 pandemic to assess how aquaculture activities have been affected by the pandemic, and to explore how these impacts compare to those from climate change. A positive correlation between the effects of the two categories of drivers was detected, but analysis suggests that the pandemic and the anthropogenic stressors affect different parts of the supply chain. The immediate measurable reported losses varied with aquaculture typology (land vs. marine, and intensive vs. extensive). A comparably lower impact on farmers reporting the use of integrated multitrophic aquaculture (IMTA) methods suggests that IMTA might enhance resilience to multiple stressors by providing different market options under the COVID-19 pandemic. Results emphasize the importance of assessing detrimental effects of COVID-19 under a multiple stressor lens, focusing on areas that have already locally experienced economic loss due to anthropogenic stressors in the last decade. Holistic policies that simultaneously address other ongoing anthropogenic stressors, rather than focusing solely on the acute impacts of COVID-19, are needed to maximize the long-term resilience of the aquaculture sector
Effect of background tank color in combination with sand substrate and shelters on survival and growth of Scylla tranquebarica instar
No full textEffect of tank color in combination with substrate-shelters on the survival and growth of the instar of purple mud crab, Scylla tranquebarica (initial body weight of 28.7 ± 2 mg) was investigated. Ten treatments were tested in triplicate with black (B) and white (W) tanks were set as the control, while other tanks were provided with a combination of sand substrate (S), and/or polyvinyl chloride pipes (P) as horizontal and nets (N) as vertical shelter, referred as B, BS, BSP, BSN, BSPN, W, WS, WSP, WSN and WSPN, respectively. Survival of the instar in black tanks (26.7 to 60.0%) was higher than in white tanks (20.0 to 46.7%) (P = 0.052). Survival in the horizontal shelter treatments (46.7 and 63.3%) exceeded that in the vertical shelter groups (30.0 and 50.0%) (P = 0.068). The final body weight of the instar in black tank (2.4 to 3.8 g) was significantly lower than white tank (2.6 to 4.8 g) (P = 0.02). Specific growth rate was significantly greater in sand substrate treatments (8.4 to 9.1%/day) than in controls (7.9 and 8.0%/day) (P = 0.015). In conclusion, horizontal shelter was better than vertical type, and black tank with substrate and horizontal shelter was more suitable for culture of purple mud crab instar.This work was partially funded by Universiti Malaysia Sabah (UMS) under grant SDK0028-2018
AQD Matters 2022 May - June
No full textIn this issue: 1) Eel research on spotlight in int'l conference; 2) DOST-6 eyes partnership with SEAFDEC/AQD on hatchery project; 3) Bohol-based trainees acquire skills in mangrove crab hatchery; 4) A former OJT, trainee: How SEAFDEC/AQD helped change Dr. Odin's life; 5) Technical assistance sought for Palawan central hatchery; 6) MSU's pioneer batch visit AQ
Proteus mirabilis (MJA 2.6S) from saline-tolerant tilapia exhibits potent antagonistic activity against Vibrio spp., enhances immunity, controls levels and improves growth and survival in juvenile giant tiger shrimp, Penaeus monodon
No full textOnline Version of Record before inclusion in an issue.Of several isolates from saline-tolerant tilapia exhibiting anti-vibrio activity, an isolate that demonstrated inhibitory activity with the biggest zone of inhibition against the shrimp pathogens, Vibrio harveyi and V. parahaemolyticus were chosen and investigated in this study. The isolate showed significant inhibition against the shrimp pathogens, V. harveyi and V. parahaemolyticus in a competitive assay. Upon 16S rRNA sequencing, the isolate was identified as putative Proteus mirabilis (MJA 2.6S). P. mirabilis (MJA 2.6S) exhibited extracellular protease, cellulase and amylase activities. Pathogenicity tests showed that it was not pathogenic to the shrimp even at the highest concentration of 108 CFU ml−1. Further, P. mirabilis (MJA 2.6S) improved growth and survival, stimulated higher phenoloxidase and bactericidal activities in the shrimp host and protected it from V. harveyi experimental infection. In addition, the isolate P. mirabilis (MJA 2.6S) significantly reduced the ammonia level of the pond water samples in vitro. Taken together, the results clearly showed the strong probiotic potential of P. mirabilis (MJA 2.6S) in shrimp and hence further studies are needed to determine its wider application as a probiotic in P. monodon culture
AQD Matters 2022 July - August
No full textIn this issue: 1) Oplan Balik Sugpo Update; 2) Scientists attends planning workshop for ASEAN-CGIAR; 3) AQD bids farewell to virtual OJTs as F2F mode resumes; 4) Researchers from Southeast Asia train on fish health management; 5) WPU freshwater prawn project visits SEAFDEC/AQD in Iloilo; 6) Chief Baliao shares strategies on increasing yield in exp
Nursery and grow-out culture of rabbitfish Siganus guttatus in brackishwater ponds
No full textRabbitfish Siganus guttatus is a promising aquaculture species due to its tasty meat and commands a higher price than some aquaculture species. Moreover, it has a low protein requirement, resulting in a low-cost feed input. In the 1970s, rabbitfish farming in fishponds began in the Philippines. In 1998 and 2014, SEAFDEC/AQD published manuals titled “Biology and Culture of Siganids” and “Seed Production of Rabbitfish Siganus guttatus,” respectively. However, there has been no recent publication on the nursery and grow-out culture. As a result, this manual will provide an update on the current techniques for nursery and grow-out culture operations of rabbitfish.
Research studies, particularly on diets and culture techniques, have been conducted and verified before being disseminated through this publication. The biology of Siganus guttatus is covered, as well as the brackishwater culture management techniques such as site selection, pond preparation, nursery operation, grow-out culture technique, production data, common diseases and preventions, and economic analysis.
The authors hope this manual will provide fish farmers, farm operators, feed millers, aquaculturists, technicians, and students with the basic knowledge of science-based aquaculture techniques for rabbitfish and how rabbitfish farming can become profitable
Seasonal population dynamics of Lepeophtheirus spinifer and Neobenedenia sp. coinfecting snubnose pompano (Trachinotus blochii) breeders in marine cages in the Philippines
No full textStudies on the biology and ecology of sea lice are lacking in tropical regions such as in Southeast Asia where finfish cage farming has grown dramatically in the past decades. This study investigated the seasonal population dynamics of ectoparasites infecting captive snubnose pompano (Trachinotus blochii) breeders in marine cages in the Philippines. The pompano breeders were found to be naturally coinfected with caligid copepod Lepeophtheirus spinifer and capsalid monogenean Neobenedenia sp. These breeders were monitored and examined bimonthly (n = 10 per sampling) from September 2017 to May 2018, covering the warm season and cold season in the Philippines. Our results clearly show that L. spinifer population maintain a 100 % prevalence throughout warm and cold seasons however, mean abundance and intensity increased only during the cold months (early November to early March) and displayed an oscillating trend during this period. Highest mean intensity was recorded in early January (221.4 ± 24.6; temperature = 27.5 ± 0.3 °C; salinity = 34.8 ± 0.3 ppt) while the lowest mean intensity was recorded during the warm months dipping to 12.5 ± 1.9 in early May (temperature = 30.5 ± 0.3 °C; salinity = 30.3 ± 0.3 ppt). The prevalence of adult and pre-adult was high throughout the monitoring period at 70–100 % except at the start of summer (late March to early May) for pre-adult (30–90 %). In comparison, the chalimus stages were only observed during the cold months specifically from early November to late January with prevalence of 40–80 %. The highest mean abundance (3.4 ± 0.7) and mean intensity (4.3 ± 0.6) was in early November which coincided with the first peak of the total L. spinifer population. Neobenedenia sp. occurred year-round with no significant changes in the population mean abundance and mean intensity between warm and cold seasons. This study presents comprehensive information on the seasonal population dynamics of L. spinifer and Neobenedenia sp. in the Philippines, providing valuable insights on the ecology of caligid sea louse which is fundamental in the formulation of control and management strategies of these economically significant ectoparasites.The authors thank the staff of SEAFDEC/AQD Igang Marine Station for assistance during the sample collection. This study was funded by CFOS-UPV and SEAFDEC/AQD
Effects of exogenous hormones and broodstock age on the spawning response of captive silver therapon Leiopotherapon plumbeus
No full textEvaluation of appropriate hormone and ideal broodstock age for optimal breeding efficiency may ensure the production of good quality eggs and larvae in the hatchery. In this study, the spawning response of captive silver therapon Leiopotherapon plumbeus to various hormonal treatments and broodstock age was examined. In Experiment 1, spawning success, latency period, absolute and relative fecundity, fertilization and hatching rates, and larval production of female silver therapon broodstock were determined after ovulation and spawning in response to human chorionic gonadotropin (hCG; 5000 and 10,000 IU/kg), Ovaprim (0.5 ml/kg), hCG + Ovaprim (5000 IU + 0.5 ml/kg; 10,000 IU + 0.5 ml/kg) or hCG + domperidone (5000 IU + 0.5 ml/kg; 10,000 IU + 0.5 ml/kg). In Experiment 2, reproductive performance of four domesticated broodstock age groups (1+, 2+, 3+ and 4+-year old) was examined for five consecutive months, coinciding with the spawning season. Higher dose of hCG + Ovaprim resulted in higher spawning (100%), fertilization (99.7 ± 0.1%), and hatching (85.8 ± 5.5%) rates than the other treatments. The effect of age on reproductive indices was not significant. However, better spawning performance was observed in 1+ to 3+-year old broodstock, with higher fertilization (96.8–98.5%) and hatching (63.7%–77.2%) rates than among the oldest age group (82.9% and 57.2%). Together, results suggest that the combination of hCG + Ovaprim is highly effective in inducing ovulation and spawning in silver therapon, and that domesticated broodstock up to 4+ years of age could still be used for breeding activities and seed production.This study was supported by the SEAFDEC Aquaculture Department (Br-02-F2015B). The assistance of Mr. N. B. Olorvida in the conduct of the experiment is appreciated