Southeast Asian Fisheries Development Center
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Isolation of potential probionts from brackishwater enriched with high levels of carbon source
No full textThe majority of shrimp producers utilize probiotics derived from terrestrial sources as part of their aquaculture management. The beneficial effects of terrestrial probiotics on shrimp may be affected due to environmental differences between the cultivated species and the source of the probiotics. To ensure maximum effects on the host, it is essential to use probionts derived from the host or the environment of the cultured organism. Consequently, the objective of this study was to isolate and characterize potential probionts from brackishwater by enriching the water with organic sources containing a high ratio of carbon to nitrogen (C:N). Six 10-li containers were filled with brackishwater from an estuary for a mesocosm experiment. To stimulate bacterial growth, water was enriched with either molasses or brown sugar at a C:N ratio of 15. After twenty days, all heterotrophic bacteria in the enriched water were enumerated. The in vitro antagonistic activities of distinct bacterial colonies against Vibrio harveyi, a crustacean pathogen, were evaluated on fresh Nutrient Agar plates containing 1% sodium chloride. There were 10 bacterial isolates with in vitro antibacterial activity. These bacterial isolates are categorized as belonging to the putative genera Acinetobacter, Pseudomonas, Sphingobium, and Rheinheimera. The implications of this study suggest that enriching brackishwater with organic carbon sources at high C:N ratios may increase the likelihood of isolating and developing potential probionts for shrimp aquaculture.This work was supported by the research project, “Biofloc-based Nursery Tank Production of Shrimp for Quality and Sustainable Supply of Aquaculture Products in the New Normal” funded by the Department of Science and Technology (DOST) through the Science for Change Program (S4CP) –Collaborative Research and Development to Leverage Philippine Economy (CRADLE) and monitored by DOST –Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) with Project Number 8444 awarded to CMA Caipang. The authors of this paper also appreciate the support provided by their respective institutions; namely, the University of the Philippines Visayas, Marmi Agricultural Corporation, SEAFDEC Aquaculture Department, Universitas Riau and the University of San Agustin during the preparation of the manuscript
Distribution pattern and habitat use of the protandrous shrimp Pandalus latirostris in relation to environmental characteristics in Akkeshi waters on the pacific coast of eastern Hokkaido, Japan
No full textA sampling of the protandric shrimp, Pandalus latirostris, was conducted at fixed sites from July 2015 to March 2020 in Akkeshi Bay and the connecting Lake Akkeshi on the Pacific coast of eastern Hokkaido. Based on the occurrence pattern of P. latirostris, most individuals begin mating as males at Age-1, followed by a sex change to females, spawn eggs as females at Age-2, and hatch their eggs in the spring of Age-3. Pre-hatching ovigerous females were mainly found in eelgrass beds near and in Lake Akkeshi, where the water temperature was relatively high. The females probably migrate there to hatch their eggs, making sure of the high survival and growth of the hatched larvae. Juveniles and small males were also abundant in near and in Lake Akkeshi, indicating that many larvae remained in the eelgrass beds where they hatched. These eelgrass beds play an important role in the maintenance of the shrimp population as a major egg-hatching site and nursery habitat in Akkeshi waters. With ontogenetic development, the occurrence rate of P. latirostris gradually increased on the offshore side of Akkeshi Bay, with its body size being larger. As P. latirostris grow, they will probably disperse to the offshore side of Akkeshi Bay. However, the density of P. latirostris in the eelgrass bed in the bay near the lake was extremely high, with its strong preference at all ontogenetic stages. This eelgrass bed would help maintain the shrimp population as a “key habitat” for the shrimp. The site-specific environmental characteristics of vegetation beds influence the distribution and abundance of individuals within a population of P. latirostris through their growth and the associated change in habitat preference. In this study, the importance of maintaining the diverse habitats of P. latirostris will be discussed as part of the shrimp stock management measures
Bacterial diseases of tilapia, their zoonotic potential and risk of antimicrobial resistance
No full textTilapia culture is an important source of income and nutrition to many rural families. Since 2000, the production of tilapia increased and reached domestic and global markets. Major farmed species is Nile tilapia (Oreochromis niloticus), in earthen ponds and cage cultures. Intensification contributed to global tilapia disease outbreaks, with bacterial infections causing mortalities and morbidities, threatening sustainable production. At tilapia farms, high nutrient concentrations, water temperature and fish densities enhance bacterial growth including virulent bacterial clones and potential zoonotic bacteria. Global warming favours this. This review respectively provides a comprehensive overview of the most common and emerging bacterial pathogens, diseases, clinical presentations and diagnostics of tilapia, including bacteria and diseases with zoonotic potential. First, common bacterial disease outbreaks, including streptococcosis, motile Aeromonas septicaemia, francisellosis, columnaris disease and vibriosis are described. Then, information on emerging bacterial infections of concern for tilapia, like edwardsiellosis through Edwardsiella ictaluri and E. tarda, as well as Aeromonas schubertii is provided. Reports of infectious bacterial tilapia disease outbreaks from other bacteria, including Lactococcus garvieae, Aerococcus viridans, Pseudomonas spp., Mycobacterium marinum and Chlamydia spp., and others are reviewed. Furthermore, bacteria with zoonotic potential, like Streptococcus agalactiae ST283, S. iniae, Aeromonas sp., E. tarda, Vibrio vulnificus pathovar (pv) piscis and M. marinum are included in the review, to provide the most current overview of the disease risks affecting production and post-harvest stages. Additionally, the status and risks of antimicrobial resistance in bacteria from tilapia and other cultured fish through imprudent use of antibiotics, and its future at a global level are provided.This study was supported by two FAO projects namely: GCP/GLO/979/NOR: Improving Biosecurity Governance and Legal Framework for Efficient and Sustainable Aquaculture Production and GCP/GLO/352/NOR: Responsible use of fisheries and aquaculture resources for sustainable development, both funded by the Norwegian Agency for Development Cooperation (Norad)
Histidine requirement of snubnose silver pompano Trachinotus blochii
No full textHistidine is necessary for the formation and repair of tissues to mitigate the effects of cataract on some fish species. Although the requirements for dietary amino acids of several Trachinotus species have been reported, the quantitative histidine requirement for a cost-effective diet for snubnose pompano or Trachinotus blochii, a high value finfish species in the Philippines, has been limited. A 90-day growth experiment determined the dietary histidine requirement of juvenile snubnose pompano (0.19±0.03 g). Six isonitrogenous, isolipidic, and isoenergetic diets consisted of a control diet with 0% histidine inclusion level (basal histidine level of 0.65%) and five diets with histidine inclusion levels of 0.15 (0.80%), 0.3 (1.1%), 0.45 (1.55%), 0.6 (2.15%), and 0.75% (2.9%). To simulate the pompano whole-body amino acid composition, essential amino acids were added in the diet. Fifteen pompano juveniles per tank in three replicates were stocked randomly in 250-L fiberglass tanks and were fed to satiation for 90 d. When the dietary histidine level and percent weight gain were analyzed via quadratic regression, a dietary histidine level of 1.61 g per 100 g diet or 0.357 g per 100 g protein is required for juvenile snubnose pompano. Moreover, the occurrence of cataracts was not observed in fish fed all dietary treatments.SEAFDEC/AQD under FD-02-F2015T is acknowledged for funding this study
Estimating the economic benefits and costs of conserving marine protected area in San Jose, Antique, Philippines
No full textThe establishment of marine protected areas (MPAs) in the Philippines becomes a priority management strategy to conserve marine biodiversity and address the problem of declining marine resources. Economic studies can be a viable tool to determine MPA as a management option by evaluating their benefits and costs to the community. In order to determine the economic benefits of MPAs in San Jose, Antique, the total economic value of the resource consisting of direct and indirect use and non-use values was determined in 2016. Direct benefits from revenues and tourism amounted to Php 247,739.61 at the time of the study. Concurrently, the indirect functional benefits of MPA amounted to Php 2,162,235 using the benefit-transfer method. In measuring the non-use values of the MPA, the contingent valuation method was used to elicit the people’s willingness to pay for the MPA conservation program. The mean willingness to pay (WTP) of 260 participants equals Php 219.00, and the social WTP amounted to Php 5,725,136.89. The total benefits of managing the MPA amounted to Php 8,135,111.50, which exceeded the cost of conserving the MPA, which amounted to only Php 1,235,363.30. The net present values across 25 year period and different interest rates generated positive results
Reproduction, early development, and larval rearing of the climbing perch Anabas testudineus (Teleostei: Anabantidae) in captivity
No full textInduced spawning, early development, and larval rearing of the climbing perch Anabas testudineus were examined under captive conditions. Five female climbing perch [125.33 ± 3.27 mm standard length (SL); 70.67 ± 5.59 g body weight (BW)] were each paired with apparently mature males (108.50 ± 3.97 mm SL; 39.27 ± 4.70 g BW) and induced to spawn with 5,000 IU human chorionic gonadotropin (hCG) + 0.5 mL Ovaprim/kg BW. All hCG + Ovaprim-injected fish spawned 9 – 11 h after hormone administration but saline-injected fish (control group) failed to spawn. Mean egg production per female, fertilization and hatching rates, and larval production per female were 7,667 ± 1,313, 98.11 ± 1.63%, 61.01 ± 19.92%, and 4,435 ± 1,041, respectively. Fertilized eggs (1.52 – 1.96 mm in diameter) were almost spherical, non-adhesive, transparent, and buoyant due to a large, single oil globule (515 ± 33 µm in diameter). First cleavage appeared 30 min post-fertilization (MPF) and egg development lasted for 20 – 24 h post-fertilization (HPF) (29°C). Newly hatched climbing perch larvae [1.73 ± 0.08 mm in total length (TL)] with yolk volume (YV) and oil globule volume (OGV) of 0.545 ± 0.104 mm3 and 0.072 ± 0.013 mm3, respectively had no pigmented eyes or functional mouth parts and digestive tract, and immobile with the yolk sac pointed upward. Eyes became pigmented and both mouth and anus opened in 1 d old larvae (2.09 ± 0.04 mm TL) in preparation for exogenous feeding. Except for body depth (BD) and pre-anal length (PAL), a general increase in TL (1.73 – 3.72 mm), eye diameter (ED) (0.164 – 0.378 mm), head length (HL) (0.205 – 0.923 mm), and mouth gape (MG) size (0.308 – 0.552 mm) was observed, coinciding with yolk resorption in 7 d post-hatched larvae. Climbing perch larvae were reared at four stocking densities (25, 50, 75, 100 larvae L-1) and fed solely on live food (Brachionus rotundiformis from days 2 to 12 and Artemia nauplii from days 13 to 40) or co-fed live food and microparticulate diet (MPD) (Artemia nauplii from days 2 to 15 and Artemia + MPD from days 16 to 40). Mean survival rates at lower densities (25 – 50 larvae L-1) were significantly higher than those reared at 75 and 100 larvae L-1 (P < 0.05). Furthermore, climbing perch larvae co-fed Artemia nauplii and MPD showed better survival (28.67 – 81.00%) than those fed solely on live food (24.88 – 64.00%). However, at the end of the 40 d trial period, growth parameters did not vary significantly among densities (P > 0.05), except for the condition factor in larvae co-fed Artemia nauplii and MPD. Taken together, results demonstrate the effectiveness of hCG + Ovaprim for captive breeding and observations on the early development of climbing perch, and the feasibility of rearing the larvae at 25 – 50 L-1 on a combination of Artemia nauplii and MPD under laboratory conditions.This study was supported by the SEAFDEC/AQD (Nr-02-F2013B and Br-02-F2015B)
Fresh chilled and fresh frozen cephalopods - Product standard
No full textThis Standard applies to fresh chilled and fresh frozen cephalopods of the Loliginidae, Sepiidae and Octopodidae families for direct consumption or further processing
Complete genome sequence of Vibrio parahaemolyticus strain PH1273, isolated from aquacultured shrimp in the Philippines
No full textWe announce the complete genome sequence of Vibrio parahaemolyticus strain PH1273. This strain was collected from a Penaeus vannamei pond in the Philippines in 2015. Genome analysis revealed that it lacks the gene pirAB responsible for causing acute hepatopancreatic necrosis disease but encode multiple secretion systems and the associated effectors
Seaweed Gracilariopsis heteroclada, formulated flaked diet, and a combination of both as feed for the abalone Haliotis asinina: Effect on growth and survival
No full textThis paper compares the effect of feeding the abalone Haliotis asinina with seaweed (SW), formulated (FD), and mixed (SW+FD) diets. The feeding experiment, in six replicates, was conducted in a tank facility and lasted for 10 months. At the end of the experiment, abalone fed mixed diets had significantly the highest mean shell length and body weight (45.90±0.19 mm, 22.82±0.31 g), followed by those fed seaweeds (43.47±0.17 mm, 18.25±0.26 g), and lastly, by those fed formulated diets (41.78±0.18 mm, 15.76±0.22 g). Mean growth rates were significantly higher in abalone fed mixed diets at 1.48±0.03 mm and 1.69±0.04 g mo−1 than those fed seaweeds (1.26±0.03 mm, 1.27±0.06 g mo−1) or formulated diet (1.06±0.09 mm, 1.00±0.11 g mo−1). Survival was consistent 1 month from the start of culture until harvest—highest in abalone fed mixed diets (78.81±2.48%), followed by those fed seaweeds (70.12±4.07%), and lastly formulated diet (64.53±4.61%). Moreover, feed conversion ratios (FCR) were significantly lower in abalone fed mixed diets (15.48±0.69) and formulated diet (18.07±3.50) compared with those fed seaweeds (41.31±2.36). The body weight to shell length ratios (BW:SL), which were the same in all treatments at the start of the experiment (0.19 g mm−1), increased to 0.51, 0.44, and 0.38 in abalone fed mixed diets, seaweeds, and formulated diet, respectively. Based on the results of this experiment, giving abalone a mix of formulated and natural diets is the best feeding regime. The importance of a balanced and more nutritional diet on the well-being of the abalone was observed in this study.The authors greatly appreciate the Southeast Asian Fisheries Development Center Aquaculture Department (SEAFDEC/AQD) for funding the study (Study Code: FD-04-M2020T)
AQD Matters 2023 January - February
No full textIn this issue: 1) SEAFDEC backs gov't bid to put up feed mill plants; 2) SEAFDEC/AQD welcomes Usec Bayate as PH Council Director; 3) SEAFDEC/AQD's expertise in formulating cost-efficient feeds sough