Southeast Asian Fisheries Development Center
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AQD Matters 2024 September - October
No full textIn this issue: SEAFDEC-NFRDI collab reaps 3 tons of shrimp; Scientist completes study visit in Japan to enhance SEAFDEC/AQD's research on eels; SEAFDEC/AQD collects seaweeds for tissue propagation; SEAFDEC/AQD explores Liguasan Marsh for prawn farming potential; SEAFDEC-NFRDI research on pompano yields 1.1 tons in partial harvest; SEAFDEC/AQD organizes 2nd sandfish training of 2024; Fukui Prefectural University trains at SEAFDEC/AQD; FAO team visits SEAFDEC/AQD; SEAFDEC/AQD trains BFAR staff on milkfish culture; Future tiger shrimp breeders find new home in broodstock facility; SEAFDEC/AQD harvests over 5 tons of black tiger shrimp; SEAFDEC/AQD joins PH's 'biggest' agribusiness trade fair; Aquaculture innovations promoted at 26th Davao Agri Trade Expo; MO, BFS employees enjoy team-building activity; SEAFDEC/AQD holds annual review and planning meeting; DA-BAR keen to partner with SEAFDEC/AQD; PhilHealth seminar updates staff on benefits, Konsulta Packag
Effects of seawater temperature fluctuations on local communities through kelp production in the Pacific coastal area of eastern Hokkaido, Japan
No full textData on the landing value for each of the eight fisheries commodities in small-scale coastal fisheries in Nemuro City was collected and analyzed to understand the importance of kelp fishery in local communities along the Pacific coast of eastern Hokkaido. Over the past 25 years from 1991 to 2015, a trend in small-scale coastal fisheries in the region has significantly varied. However, in all year groups, the landing value of the kelps accounted for about 40% of its total value, indicating no significant change in its importance. The kelp fishery always has a profit center within the small- scale fisheries operations in the region. The influences of seawater temperature and the physical environmental factors of the seafloor on kelp production were investigated using GIS. Mean seawater temperatures in July, September, and October of the year before the harvest negatively correlated with the kelp harvest in Nemuro City from 2006 to 2014. The kelp length was mainly explained by the water temperatures in September and July of the year before the harvest, bottom current velocity, and water depth. These results indicate that the water temperature during summer and the seafloor physical environment have significant effect on kelp growth. Recent increases in seawater temperature along the Pacific coast of eastern Hokkaido during summer would significantly impact the local socio-economy through reduced kelp production.This study was mainly supported by the management expense grant of FRA, and its part was funded by KAKEN grant (22H05203, H. Kuroda) of the Ministry of Education, Science, and Culture
Pichia kudriavzevii as feed additive in Nile tilapia (Oreochromis niloticus) diet
No full textYeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their nutritional benefits. Despite their potential, marine and mangrove yeast species used in the aquaculture industry have received little attention in the Philippines. Pichia kudriavzevii (A2B R1 ISO 3), sourced from bark samples, was selected and mass-produced due to its high protein content and amino acid profile. The dried biomass of P. kudriavzevii was incorporated into the diets of Nile tilapia (Oreochromis niloticus) juveniles at varying inclusion levels (0, 1, 2, and 4 g/kg diet) and its effect on their growth performance, body composition, and liver and intestinal morphology was assessed after 40 days of feeding. The groups that received P. kudriavzevii at a concentration of 2 g/kg diet exhibited higher final body weight, percent weight gain, and specific growth rate in comparison to the other treatment groups. Whole body proximate composition did not vary among the dietary groups. Intestinal and liver histopathology also indicated no abnormalities. These findings suggest the potential of ascomycetous P. kudriavzevii as a beneficial feed additive in Nile tilapia diets, warranting further investigation into its long-term effects and broader applications in fish culture.Department of Science and Technology—Accelerated Science and Technology Human Resource Development Program (DOST-ASTHRDP), National Research Council of the Philippines—Project E-250, University of Santo Tomas, Research Center for the Natural and Applied Sciences, Southeast Asian Fisheries Development Center—Aquaculture Department (SEAFDEC/AQD), and the Government of Japan—Trust Fund (8300-B-RD-FD0120)
Pathogenicity of Aeromonas veronii from Nile tilapia (Oreochromis niloticus) and efficacy of fish oral vaccine against motile aeromonad septicemia in tank trials
No full textDownload Supplementary MaterialMotile aeromonad septicemia (MAS), caused by the Aeromonas species, has been a serious problem in fish health management, particularly in Nile tilapia (Oreochromis niloticus). This study characterized an Aeromonas species isolated from farmed tilapia fingerlings in Binangonan, Rizal, Philippines, and tested for its pathogenicity in tank trials. The isolate, designated as Aeromonas veronii DFR01 (Diseased Fish Rizal), was identified based on 16S rRNA phylogenetic analysis, 16S rRNA homology, and MALDI-TOF mass spectrometry. Its biochemical profile was generated from API and Biolog Gen III systems. A median lethal dose of A. veronii DFR01 was determined to be 107 CFU/mL in tank trials and was utilized as a whole-cell inactivated antigen for oral vaccine development. The immunized tilapia fingerlings produced elevated levels of immunoglobulin M (IgM) in the blood as determined by an enzyme-linked immunosorbent assay (ELISA). There was a significant increase in IgM levels 14 days post-vaccination. A quantitative polymerase chain reaction (qPCR) showed increasing levels of IgM gene expression after vaccination until 38 days of culture. Vaccinated fish showed 25–35% cumulative mortality after the challenge, while non-vaccinated-challenged fish showed 75% mortality. The findings of this research suggest that the fish oral vaccine may prove beneficial for farmed tilapia populations. The vaccine elicited improved immune responses in the fish and resulted in higher survival rates.Financial support for this study came from a research grant to AMA from the Department of Science and Technology (DOST) Philippine Council for Aquatic and Marine Research and Development (PCAMRD), now the Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development (PCAARRD; Program Code: 2021-01-A1-CRADLE-3042; approved 3 November 2021). Many thanks to the Trinity University of Asia and Santeh Feeds Corporation for the support and counterpart funding
Establishing a community-based sea cucumber ranch: Merging science with local knowledge
No full textSea cucumbers are expensive, but natural wild stocks are overfished, especially in the tropics. This is why sea cucumber farming is increasingly gaining popularity worldwide, aside from the anticipated high economic gains from its dried food products. Hatchery production and practical farming technologies are available and have been demonstrated in some countries in the Indo-Pacific. However, there are limitations in the establishment of sea cucumber farms elsewhere, especially in the Philippines. The most basic bottleneck is in the identification of the potential pilot site to start a sea-based farming venture.
A project at SEAFDEC/AQD, funded by ACIAR, aims to promote community-based production of the tropical sea cucumber Holothuria scabra or sandfish in the central Philippines, among other sites. Sandfish sea ranching involves culturing hatchery-bred native sandfish juveniles on intertidal coasts through a multi-stakeholder management approach. Although a number of scientific studies have established some general criteria for good ecological habitat for growing sandfish, the project has shown that technically generated environmental data is not sufficient information to guarantee a successful farming site. It should be complemented with traditional ecological knowledge to integrate sociocultural and local governance dimensions. Achieving consensus and cooperation among stakeholders (e.g. technical institutions, government, and local communities) are crucial in the initial planning and establishment of a pilot sea cucumber production site.
This article highlights the importance of merging traditional ecological knowledge and science-based data as an essential prerequisite in project planning processes and implementation activities. This key strategy ensures that the project is aligned with the needs and expectations of the local stakeholders in order to promote long-term active commitment and engagement, leading to project sustainability
AQD Matters 2024 May - June
No full textIn this issue: 1) Seizing the El Niño advantage in aquaculture; 2) Agreement inked for multi-species marine hatchery in Davao Occidental; 3) 56th SEAFDEC Council Meeting highlights key fisheries management initiatives; 4) Pompano sampling at NFRDI-FFRDC; 5) Five fisheries graduates complete intensive aquaculture training course; 6) SEAFDEC-NFRDI project collab nets 4.3 tons of whiteleg shrimp; 7) SEAFDEC/AQD stocks black tiger shrimp fry; 8) Experts share insights at Livestock and Aquaculture PH 2024; 8) Multi-species hatchery taking shape in Agusan del Norte; 9) SEAFDEC/AQD hosts Regional Sea Cucumber Roadshow; 10) Japanese experts visit AQD to discuss fish disease management, aquaculture feed market; 11) Training course on seaweed micropropagation and nursery culture held for BARMM participants; 12) BFAR staff acquire skills in mangrove crab culture; 13) 12 complete training on fish nutrition and feed developmen
High genetic diversity in anguillid glass eels across three Southeast Asian countries revealed through mitochondrial DNA D-loop sequences, with notes on population structure
No full textUnderstanding the genetic diversity and population structure of anguillid eels is crucial for effective management. In this study, we used the mitochondrial DNA (mtDNA) D-loop marker to identify anguillid glass eels and assessed their genetic diversity across six sampling sites spanning three Southeast Asian countries. We also examined the population structures of Anguilla marmorata and A. celebesensis. We validated nine distinct species and subspecies of anguillid eels from 465 specimens collected in Indonesia (n = 246), the Philippines (n = 119), and Vietnam (n = 100). High gene diversities were observed across the species, ranging from 0.979 (A. celebesensis) to 1.000 (A. bicolor bicolor, A. marmorata, and A. interioris). Correspondingly, nucleotide diversity values were relatively low, varying from 0.036 (A. marmorata) to 0.057 (A. interioris). A. marmorata (n = 162) displayed a broad distribution, being observed across all six sites, with a significant yet low average fixation index of 0.05755. Pairwise comparisons of FST values between Cimandiri and other locations (except for Cagayan) were relatively high and statistically significant (p < 0.01), indicating significant genetic differentiation of Cimandiri samples compared to most locations in this study. On the other hand, A. celebesensis (n = 110), exhibited a non-significant and low fixation index (0.007), indicating no genetic differentiation in samples from Poso and Poigar Rivers, Indonesia. Our findings highlight the essential need for coordinated management strategies among regions that share common stocks. Additionally, this study underscores the efficacy of the mtDNA D-loop in precisely identifying glass eel species/subspecies and elucidating the genetic diversity and population structure of tropical anguillid eels.This research received financial support from the Japanese Trust Fund under the Project "Sustainable utilization of Anguillid eel in the Southeast Asia region"
Female mate choice for male size in a freshwater goby under experimental conditions eliminating inter-male interference
No full textThe preference of females for male body size was examined in an experimental environment where direct interference between males was eliminated. In this environment, females preferred to spawn with larger males. To understand the preference of females for larger males, paternal care and egg defence abilities and paternal cannibalism intensity were further tested with respect to the body size of males. The dead egg rate for an egg mass during the paternal care period was not related to the body size of the paternal males. However, larger males could defend their egg masses more successfully against nest intruders than smaller ones. During the paternal egg care period, paternal males often consumed eggs in their nests. In particular, smaller males compared to females caused paternal brood cannibalism. High egg defence ability and low paternal cannibalism intensity are the most plausible reasons for females to choose larger males.This study was supported by the management expense grants of National Research Institute of Fisheries Science
Simulated transport of silver therapon (Leiopotherapon plumbeus) fingerlings at different durations and loading densities: Effects on survival and water quality
No full textThe silver therapon, Leiopotherapon plumbeus, is being promoted as a new species for aquaculture. However, information on the optimal conditions for the transport of this species for grow-out culture needs to be established to avoid stress and unnecessary mortalities. This study examined the effects of duration of transport and loading density on survival and water quality during simulated transport of silver therapon (Leiopotherapon plumbeus). Hatchery-produced fingerlings [1.30±0.34 g body weight (BW); 44.30±3.77 mm total length (TL)] were held in double-layered oxygenated plastic bags at three transport durations (6 h, 9 h, and 12 h) and densities (40 fish bag-1, 80 fish bag-1, and 120 fish bag-1) in triplicates. Mean survival rates were not significantly affected by both duration of transport (P=0.321) and loading density (P=0.345). However, a highly significant effect of duration of transport on dissolved oxygen (DO) and pH (P=0.000), and a significant effect on Total Ammonia Nitrogen (TAN; P=0.039) and total bacterial count (TBC; P=0.034) were evident. Similarly, water quality parameters were significantly influenced by loading density (P=0.000), with lower DO and pH levels, and higher TAN and TBC recorded at 120 fish bag-1 density. Since a very high survival rate (>99%) is achieved at the highest loading density of 120 fish bag-1 up to 12 h transport, this density can be recommended to transport silver therapon fingerlings. However, chemical treatments using either salt, methylene blue, or tropical almond leaf extract in transport water may be used to reduce the high bacterial count during transport.This study was supported by the SEAFDEC Aquaculture Department (Br-02-F2015B). The authors thank M. J. Reyes, J. C. Unida, J. dela Cruz, Jr., R. Lazartigue, R. Celebre and N. Olorvida for counting and packing the fingerlings