Southeast Asian Fisheries Development Center
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Growth performance of milkfish (Chanos chanos) cultured in marine pen designed for integrated multi-trophic aquaculture (IMTA)
Get PDFIn this study, common models were tested to determine the best-fit model for milkfish cultured in marine pen and the controlling factors of specific growth rate and condition factor were investigated
Integrating bivalves in IMTA system using earthen ponds
Get PDFThis study aimed to integrate the mangrove clam Anodontia philippiana, which has the capacity to assimilate sulfide in a pond culture system with milkfish Chanos chanos and seaweeds Gracilariopsis heteroclada. Specifically, it aimed to know the effects of integrating other commodities on the growth and survival of milkfish, the primary culture species in IMTA in ponds
Vibrio load and percentage composition of sucrose‐fermenting vibrios in Nile tilapia (Oreochromis niloticus) cultured in brackish water earthen ponds and biocontrol potential of recycled tilapia‐conditioned greenwater against population growth of V. parahaemolyticus and non‐sucrose‐fermenting vibrios in the grow‐out culture of white leg shrimp (Litopenaeus vannamei)
No full textVibrio are known opportunistic pathogens of pond-cultured fish and shrimp. This study determined the presumptive Vibrio count (PVC) and percentage composition of “beneficial” sucrose-fermenting vibrios (SFVs) and “pathogenic” non-SFVs in the water, sediment, gills and intestines of healthy tilapia Oreochromis niloticus collected every 2 weeks from Days 30 to 120 post-stocking in brackish water earthen ponds. PVCs in water and sediment ranged from 102–104 CFU/ml/CFU/g while in tilapias' gills and intestines, PVCs ranged from 103–106 CFU/g and 102–106 CFU/g, respectively, with SFVs dominating in water, sediment, gills (≥50%), and intestines (≥80%) of tilapia. Because use of tilapia-conditioned green water (TCGW) for shrimp's grow-out culture has been reported effective against acute hepatopancreatic necrosis disease outbreaks caused by V. parahaemolyticus, PVC, SFVs/non-SFVs (%), and V. parahaemolyticus count (VPC) in the recycled TCGW and Litopenaeus vannamei's hepatopancreas were also examined from stocking until 105 days of culture (DOC) in earthen ponds. PVCs ranging from 102–103 CFU/ml and 103–104 CFU/g were noted in water and shrimp's hepatopancreas, respectively. While non-SFVs population in water varied, a downward trend typified by an abrupt 50% reduction was noted in hepatopancreas at DOC 42, and remained or further dropped until DOC 105. VPCs in water likewise varied (undetectable–102 CFU/ml) while in hepatopancreas, counts dropped to undetectable level from DOC 70 onwards. Current data illustrate that remarkable shift of SFVs' dominance in the water and concomitantly in shrimp's hepatopancreas, plays a pivotal role in regulating non-SFVs proliferation in shrimp's hepatopancreas via competitive exclusion.This study was funded by SEAFDEC AQD (study code: FH02-F2013-T) and in part by the Department of Science and Technology-National Research Council of the Philippines (DOST-NRCP) (NRCP Project No. E-225)
Effects of feeding rate and sediment depth on the survival, growth performance, and biomass of mud polychaete Marphysa iloiloensis from early juvenile to adult in grow-out tanks
No full textPolychaete aquaculture has progressed in some countries to meet the high demand of fish bait and aquaculture industries. However, knowledge on the aquaculture requirements of polychaetes in the grow-out is still scarce. The present study aimed to determine the optimal feeding rate (FR) and sediment depth (SD) for the grow-out culture of mud polychaete Marphysa iloiloensis from early juvenile to adult stage. The effects of two FRs (50 and 100 g m−2) with three different levels of SD (2, 3, and 5 cm) on M. iloiloensis survival, growth performance, and biomass were evaluated. The study was performed in a 2 × 3 factorial experiment using completely randomized design with four replicates per treatment that lasted 120 days. Early juveniles (30 days old) were stocked in glass tanks at 1000 individuals m−2 and grown for 120 days (herein refer as 'adult', with musculature and capable of reproduction). Regardless of FR, M. iloiloensis had the highest survival of 45 ± 2% in 5 cm SD but statistically comparable to 3 cm SD (34 ± 5%), while survival was significantly lowest in 7 cm SD (26 ± 3%). The levels of nitrite (NO2) and total ammonia nitrogen (TAN) was significantly higher in the rearing water of 100 g m−2 FR than in 50 g m−2 FR. Higher FR resulted to poor water quality and appeared to contribute to the low M. iloiloensis survival in 100 g m−2 FR. Growth performance was similar among treatments. There was a significant interaction between FR and SD on M. iloiloensis biomass (p < 0.05). In 50 g m−2 FR, no difference was observed in the different levels of SD while in 100 g m−2 FR, biomass was significantly higher in 5 cm SD than in 7 cm SD (p < 0.05). M. iloiloensis biomass in 50 g m−2 FR was higher compared to 100 g m−2 FR, regardless of the SD. Overall, the culture of M. iloiloensis using 50 g m−2 FR in 3–5 cm SD showed the best survival and biomass. Based on these findings, it is recommended that the grow-out culture of M. iloiloensis from early juvenile to adult should follow the 50 g m−2 FR and should be done in tanks with 3–5 cm SD to improve production.The study was funded by the Aquaculture Department, Southeast Asian Fisheries Development Center (SEAFDEC/AQD) under the study code TV-01-Y2019
Phylogenetic analysis of tilapia lake virus (TiLV) isolates from the Philippines based on partial genome segment 3 sequences
No full textThis study aimed to expand current knowledge on TiLV genetic diversity by sequence analysis of a portion of genome segment 3 of TiLV detected from the Philippines. This includes a recently deposited sequence in GenBank (Accession No. LC504279) and six new sequences from cases of infection reported from 2017 to 2020. Phylogenetic analysis of 179 bp fragment of segment 3 showed that the seven TiLV isolates from the Philippines can be divided into three phylogenetic groups. When comparing all sequences, unique nucleotide substitutions and amino acids were noted among these groups. Variation in mortality rates in naturally infected samples was also observed; however, poor environmental conditions during the disease outbreak may also contribute to the mortalities. These suggest the presence of at least three phylogenetic groups of TiLV in the Philippines which has significant implications for the future development of a vaccine, diagnostic kits, and genetic selection programs.This work was funded by SEAFDEC/AQD
Communicating science information to the fishing community in the Philippines
No full textThe world is currently experiencing an age of information overload, as information about anything and almost everything is easily obtainable. However, essential information that could help a community strive and survive is often left unread in scientific papers and grey literature, thus unable to reach its intended audience. Fishers, specifically in developing countries such as the Philippines, are still known to be information-poor despite the rich scientific knowledge produced by concerned agencies. This chapter describes and analyses the information needs and seeking behaviour among fishers in the coastal communities in Iloilo, Philippines. Taking the initiative and time to profile how specific groups consume information can help narrow the information gap and aid concerned agencies to create and conceptualise successful, sustainable, and effective information, education, and communication campaigns
Grazing periodicity, grazing rate, feeding preference, and gut examination of early juveniles of abalone Haliotis asinina–fed five benthic diatom species
No full textThis study evaluated the suitability of five diatom species (Amphora sp., Cocconeis sp., Navicula ramosissima, Nitzschia sp., and Tryblionella sp.) as food to abalone Haliotis asinina early juveniles (5-mm shell length). Grazing periodicity, grazing rate, and feeding preference were measured; at the same time, abalone gut content was examined. Grazing incidence appeared to be continuous with significantly higher grazing intensity observed at nighttime from 6 p.m. to 10 p.m. (79%) than at daytime from 10 a.m. to 2 p.m. (40%) (p 0.05). Broken cells of Amphora sp. (22%) were significantly higher in the gut of H. asinina compared to Cocconeis sp. (2.8%), N. ramosissima, (1.8%), and Tryblionella sp. (0.2%) although the abundance of Nitzschia sp. (6%) was not significantly different from Amphora sp. (p > 0.05). Early juveniles showed significant preference for Cocconeis sp. (18.6%), followed by Nitzschia sp. (16.2%), N. ramosissima (13.9%), and Amphora sp. (13.4%), with the least preference for Tryblionella sp. (7.8%). Survival of H. asinina was similar in 4 diatom species (46–71%) except in Tryblionella sp. (8–12%). These findings suggest that diatom species Cocconeis sp., Nitzschia sp., Amphora sp., and N. ramosissima are the suitable live food for H. asinina early juveniles. Knowledge from this study would contribute to the development of a feeding protocol that would maximize production of H. asinina early juveniles in the hatchery.The Department of Science and Technology—Philippine Council for Agriculture and the Natural Resources Research and Development funded this study under the National Abalone Program of the Philippines, project on refinement of hatchery technology for the donkey’s ear abalone (Study code: NR04-M2009T), with the Aquaculture Department of the Southeast Asian Fisheries Development (SEAFDEC/AQD) as implementing agency
Settlement of oyster Magallana bilineata (Röding, 1798) spat in the natural environment: Seasonality and substrate texture preference
No full textThis study determined the seasonality of Magallana bilineata spat settlement in a natural oyster bed and established surface texture preference of competent larvae by comparing the numbers of spat settling on the smooth and rough surfaces of ceramic tiles over a period of 31 months. This will guide farmers when to deploy cultches to maximise spat harvest. Regardless of tile orientation, spat numbers were significantly higher on the rough side (129.07 ± 9.3 m−2) than on the smooth side (66.95 ± 7.0 m−2). Spat collection was highest in March, June and July in each of 2015, 2016 and 2017. There was no significant correlation between the number of spat settling in each month with temperature, salinity, pH, dissolved oxygen (DO), sulphide, phosphate, nitrate, nitrite and ammonia concentrations, plankton density measured at deployment and retrieval of tiles, except for DO during deployment. The only significant correlations with mean shell length (SL) were with DO and ammonia during tile retrieval. Mean SL did not significantly differ between tile orientations and surfaces but differed between months, being highest in August 2015 and August 2016. From these results, it is best to deploy roughened cultches in this particular area in March, June and July.The Project Team greatly appreciates the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD) (Project Code 6286-TRD-DOST-O4) and the Aquaculture Department of the Southeast Asian Fisheries Development Center (SEAFDEC/AQD) (Study Code FS-02-M2014T) for funding the study; Mr. Patrick Frances Alicante and Mr. Silverio Tibudan for their kind assistance in the field; the Local Government Unit and the people of New Washington, Aklan for welcoming the team and allowing the conduct of the experiment in their locality; and the journal reviewers for painstakingly reviewing the manuscript