Now showing items 1569-1588 of 3386

    • magazineArticle

      I'd like to invest in aquaculture, what choices do I have? 

      MB Surtida - SEAFDEC Asian Aquaculture, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The Philippines, which lies 5th in terms of aquaculture production world-wide, has one of the highest per capita fish consumptions in the world. This makes aquaculture a very promising industry when viewed in relation to the decreasing catch from natural sources, which is due mainly to rapid population growth. A new investor in aquaculture has many decisions to make, foremost of which is the site for the farm. A table is given listing the major species which are being raised profitably in the Philippines. It also includes information as to how and where the species are cultured, the extent to which the sector is commercialized, and economics and costings.
    • magazineArticle

      An idealized rural coastal zone management integrating land and water use 

      NJ Dagoon - SEAFDEC Asian Aquaculture, 1998 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Various countries have formulated special integrated coastal zone management (ICZM) strategies which seek to both manage development and conserve natural resources and integrate and coordinate the relevant people sectors and their functions and roles within the bounds of this rich realm. Concerns that may be addressed by ICZM include: 1) Natural resources degradation; 2) Pollution; 3) Land use conflicts; and, 4) Destruction of life and property by natural hazards. Some prevalent sources of environmental impacts (livelihoods) are listed, together with some recommendations to the concerns which they may raise in relation to coastal zone management: agriculture; aquaculture; fisheries; forestry; human settlements; tourism; and, transport industry.
    • Article

      Identification and characterization of vitellin in a hermaphrodite shrimp, Pandalus kessleri 

      ET Quinitio, A Hara, K Yamauchi, T Mizushima & T Fuji - Comparative Biochemistry and Physiology - B: Comparative Biochemistry, 1989 - Elsevier
      1. A female specific protein (FSP, vitellogenin) in hemolymph and its related ovarian protein (vitellin) of Pandalus kessleri were studied by means of electrophoretical and immunological procedures.

      2. The vitellin was purified from vitellogenic ovaries using hydroxylapatite, DEAE cellulose and Sepharose 6B columns, consecutively.

      3. The vitellin had a molecular weight of approximately 560 kD and was composed of two subunits, 81 and 110 kD, respectively.

      4. The vitellogenin concentrations in the hemolymph increased as vitellogenesis in the ovarian oocytes advanced and dropped markedly after the release of mature eggs.
    • Article

      Identification and culture of common diatoms as possible feed for Penaeus monodon 

      T Pimoljinda - SEAFDEC Aquaculture Department Quarterly Research Report, 1977 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Diatoms were collected from Buyuan Bay, and from the hatchery tanks at Tigbauan, to determine the commonly occurring species, the feasibility of culturing these species, and the potential of these selected species as food for larval P. monodon. The commonly occurring diatoms were identified as Chaetoceros calcitrans, Navicula grimmei, Nitzchia seriata, Nitzchia closterium and Amphiprora sp. These diatoms were isolated and unialgal cultures prepared. Protein content analysis using the micro-Kjildahl method gave the following result: C. calcitrans, 11 . 78%; Nitzchia seriata, 25%; Nitzchia closterium, 30 . 5%; Navicula grimmei, 9 . 06% and Amphiprora sp. 8 . 96%.

      Feeding experiments were conducted to determine acceptability of the different diatom species and percentage survival of larval stages Z1 - M2. Larvae were placed in 4-l capacity plastic containers with a stocking density of 10/l. The results of several feeding trials using the different mass-produced diatoms are summarized.

      From the data gathered, C. calcitrans appears to be the most promising candidate as feed for zoea and mysis stages of P. monodon. The average percentage survival of C. calcitrans was 63 . 76% for the 3 trials, and as high as 82 . 22% in the third trial. Comparatively high percentage survival of larvae was also recorded when Nitzchia seriata (48 . 17%) and Nitzchia closterium (67 . 6%) were given as feed, while both Amphiprora sp. and Navicula grimmei gave 0% survival. The poor results with Amphiprora sp. and Navicula grimmei may be due to their low protein content (8 . 96% and 9 . 06%, respectively) and the inability of the larvae to ingest them. Navicula and Amphiprora were observed to cling to the appendages of the larvae and to settle down in the medium making them unavailable to the larvae. Low survival was also noted when frozen C. calcitrans was used (14 . 25%). This may be due partly to the effect of the floculating agent (ALSO4.25 g/l) used in concentrating the diatoms.

      When protein contents of C. calcitrans, N. seriata and N. closterium are compared, the 2 Nitzchia species have relatively higher protein contents than C. calcitrans and, therefore, could be the more desirable feed candidates. However, few feeding trials were made using Nitzchia so that additional investigations will have to be done on this aspect.
    • Conference paper

      Identification of mud crab species in coastal areas of Pangasinan 

      RB Cerezo & MC Tapia - In ET Quinitio, FD Parado-Estepa & RM Coloso (Eds.), Philippines : In the forefront of the mud crab industry development : proceedings of the 1st National Mud Crab Congress, 16-18 November 2015, Iloilo City, Philippines, 2017 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The study was conducted to identify the mud crab species (Scylla spp.) that thrive in 12 coastal municipalities and 2 cities in Pangasinan. Ten mud crab samples were taken from each of the sampling site and classified based on Keenan et al. (1998). Likewise, the abundance and differences in size and weight of the mud crab samples were determined. The study showed that there are only three mud crab species, Scylla serrata, S. tranquebarica and S. olivacea, found in the coastal areas of Pangasinan. S. serrata was the most abundant species (54.28%), followed by S. tranquebarica (24.28%) and S. olivacea (22.14%). Crabs weighing more than 300 g (~.12 cm carapace width or CW) were obtained from the municipalities of Anda, Bolinao, Dasol, Burgos, Bani, Agno, Alaminos and Infanta. These municipalities are geographically situated in coastal areas where S. serrata are found. Crabs weighing below 300 g (~.12 cm CW) were collected from the municipalities of Sual, Labrador, San Fabian, Lingayen, Dagupan and Binmaley. These towns have mangrove areas and low saline waters where S. tranquebarica and S. olivacea thrive.
    • Article

      Identification of postlarvae of the genus Penaeus appearing in shore waters 

      H Motoh & P Buri - Researches on Crustacea, 1981 - Carcinological Society of Japan
      Diagnostic features for the identification of postlarval Penaeus found in the shore waters of the Philippines are described and categorized based on specimens caught from the wild and those hatched and reared in the laboratory.

      Differentiating features for postlarval Penaeus are given which include the relative length of the antennular flagellum, the shape of the rostrum and number of rostral teeth, the antennal spine, the spinules on the dorsal caina of the sixth abdominal segment, and chromatophore patterns.

      Postlarval Penaeus were classified into two species and two groups as follows: (1) P. monodon, larger in size with dense chromatophores, and the long inner antennular flagellum being more than 2.0 times the outer antennular flagellum; (2) P. semisulcatus, the inner flagellum being 1.6 to 2.0 times the outer antennular flagellum, the the absence of chromatophore on the middle portion of the telson and uropods; (3) P. merguiensis group, less pigmented, the inner flagellum being less than 1.6 times the outer flagellum and (4) P. japonicus group, a short rostum, presence of spinules on the dorsal carina of the sixth abdominal segment, and dense chromatophores. The determinations were confirmed by rearing experiments.
    • Article

      Identification of Pseudomonas sp. strain S3 based on small subunit ribosomal RNA gene sequences. 

      AAA Hamid, S Hamdan, RV Pakingking Jr. & F Huyop - Biotechnology, 2010 - Asian Network for Scientific Information
      Pseudomonas sp. strain S3 was isolated from Paddy (rice) field agricultural area. This organism, which can utilize a halogenated compound of D,L-2-Chloropropionic acid as sole carbon and energy source, catalyses the hydrolytic dehalogenation of both D- and L- isomers of 2-Chloropropionic acid. Identification of Pseudomonas sp. S3 is still ambiguous due to the lack of basic studies, especially their molecular genetic information. In this study, the amplified 16S rRNA gene sequence of Pseudomonas sp. S3 (Accession No. FJ968758) was compared to other nine selected gene sequences from the same group of Pseudomonas sp. and/or dehalogenase producing bacteria using in silico method. Their phylogenetic relationships were then determined. The results were analysed using MEGA4 software to ascertain its evolutionary distance by reconstructing a phylogenetic tree of these organisms. The evolutionary history and bootstrap consensus tree were inferred using the Neighbour-Joining method from 500 replicates. The tree is drawn to scale, with branch lengths (next to the branches) in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances were computed using the p-distance method and were in the units of the number of base substitutions per site. Based on this analysis, Pseudomonas sp. S3 16S rRNA gene was closely related to the Pseudomonas chlororaphis with genetic distance 0.170 base substitutions per site. S3 gene was also compared among known dehalogenase producing bacteria 16S rRNA genes. Results suggested that S3 was closely related to the Pseudomonas sp. R1 with a genetic distance 0.040 base substitutions per site. From present study, evolutionary relationships of 16S rRNA gene of Pseudomonas sp. S3 were elegantly illustrated by phylograms, comparable to a pedigree showing which microorganisms are most closely related.
    • Article

      Identification of stressors that affect white spot syndrome virus (WSSV) infection and outbreak in pond cultured Penaeus monodon. 

      EA Tendencia & JAJ Verreth - The Israeli Journal of Aquaculture-Bamidgeh, 2011 - The Society of Israeli Aquaculture and Marine Biotechnology
      White spot syndrome virus (WSSV) has been a big problem to the worldwide shrimp industry. Exposure to stressors related to physicochemical water parameters affect WSSV infection but not all WSSV infections result in outbreaks. This paper describes a detailed monitoring of important physicochemical water parameters on a farm with 11 ponds that had WSSV infection. The virus was detected in shrimp exposed to two or more simultaneous stress factors (temperature, pH, water level) or multiple stressors for a number of days. Exposure to more than three stressors resulted in an outbreak of the disease within 3-6 days. Outbreaks were experienced in ponds with a temperature of 26-27°C, a pH lower than 8.0, pH fluctuation of 1.0, and a water depth of less than 1 m. Shrimp stocked in eight of the ponds were successfully harvested after 128-173 days of culture.
    • Article

      Identification of the postlarval Penaeus (Crustacea, Decapoda, Penaeidae) appearing along shore waters 

      H Motoh & P Buri - SEAFDEC Aquaculture Department Quarterly Research Report, 1980 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Diagnostic characters for the identification of postlarval Penaeus appearing along the coastal waters of the Philippines are reviewed and categorized, based on materials from the wild and laboratory. Presently there are 7 adult known species belonging to the genus Penaeus around Panay Island and its adjacent waters, namely: P. monodon, P. semisulcatus, P. merguiensis, P. indicus, P. japonicus , P. canaliculatus, and P. latisulcatus.
    • Article

      Identifying mangrove areas for fisheries enhancement; population assessment in a patchy habitat 

      MJH Lebata, ME Walton, JB Biñas, JH Primavera & L Le Vay - Aquatic Conservation: Marine and Freshwater Ecosystems, 2012 - Wiley
      1. Small-scale fisheries are an important element of the ecosystem goods and services that mangrove habitats provide, especially to poorer coastal communities that rely most on natural resources, and have similar values to payments for ecosystem services (PES) under carbon-trading schemes.
      2. In advance of fishery-enhancement trials for the mud crab Scylla olivacea, a mark–recapture study was conducted to estimate population size and turnover in 50 ha of isolated mangrove on Panay Island, Philippines. A total of 811 crabs were released in six sessions with an overall recapture rate of 41.5 ± 3.6%. Population size ranged from 607–1637 individuals.
      3. There was a high degree of site-fidelity, with 45.5% of recaptures in the same sampling areas as releases. Total mortality was 0.79 month-1, with fishing mortality accounting for 95% of overall mortality.
      4. Von Bertalanffy and Gompertz growth models yielded estimates for L (carapace width) of 117.3 ± 14.7 and 110.6 ± 2.1 mm and for k of 2.16 ± 0.74 and 3.25 ± 0.81, respectively. Crab densities of 12–33 individuals ha-1 in the study area were lower than in other mangrove systems owing to intermittent recruitment, while growth rates indicated no limitation in terms of food supply.
      5. The study demonstrates that in specific mangrove habitats that are below carrying capacity, there is potential for fisheries enhancement to sustain or increase direct economic benefits from mangrove ecosystems and hence promote community engagement in broader conservation and PES initiatives.
    • magazineArticle

      Identifying milkfish fry 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1988 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Identifying sea bass fry 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1988 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Identifying shrimp fry 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1988 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Identifying siganid fry 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1988 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      The identity of Limnoncaea diuncata Kokubo, 1914 (Copepoda: Poecilostomatoida) from Hokkaido, Japan, with the relegation of Diergasilus Do, 1981 to a junior synonym of Thersitina Norman, 1905 

      S Ohtsuka, Js Ho, K Nagasawa, J Morozinska-Gogol & W Piasecki - Systematic Parasitology, 2004 - Springer Verlag
      Both sexes of an ergasilid copepod, Limnoncaea diuncata Kokubo, 1914, are redescribed based on planktonic specimens collected from the type-locality in Hokkaido, Japan. Comparison of this species with Thersitina gasterostei (Pagenstecher, 1861) revealed that they are conspecific. Another ergasilid genus with two claws on the antenna, DiergasilusDo, 1981, is relegated to synonymy with Thersitina Norman, 1905. The diagnosis of Thersitina is amended.
    • Brochure

      Igang Marine Station 

      Southeast Asian Fisheries Development Center, Aquaculture Department - 2019 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Illegal fishing methods 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1993 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Conference paper

      Illuminated-cage nursery of the Asian sea bass, Lates calcarifer Bloch, (Centropomidae): effects of initial body size and stocking density 

      AC Fermin - In IC Liao & CK Lin (Eds.), Cage Aquaculture in Asia: Proceedings of the First International Symposium on Cage Aquaculture in Asia, 2-6 November 1999, Tungkang Marine Laboratory, Taiwan Fisheries Research Institute, Tungkang, Taiwan, 2000 - Asian Fisheries Society; World Aquaculture Society - Southeast Asian Chapter
      This study was conducted to determine the appropriate initial body size and the corresponding stocking density of sea bass, Lates calcarifer, during nursery rearing in illuminated cages. Hatchery-produced sea bass fry of different initial sizes of 7.2 (day 15), 13.2 (day 22), and 15.2 mm (day 29) were stocked at densities between 300 and 1,500 m-3 in decreasing order with fish size. Nylon net cages (1x1x1 m) set in a protected sea cove area were individually lit at 300 lux using incandescent bulb placed at 1 m above water surface. Artificial lights attract wild zooplankton that served as prey to young sea bass. After 42 days of culture 22-day old sea bass fry with 13.2 mm TL initial size and stocked at 400 m-3 showed the highest growth (35.3 mm TL, 535.7 mg BW) and survival rates (64.4%). At a stocking density of 800 m-3, the survival rate was the second highest at 43%. Although day 15-fry at 7.2 mm TL initial size showed higher specific growth rates (11 % day-1) and size at harvest (29-31 mm TL, 346.2-374.4 mg BW), survival rates (11-15 %) were lower than the day 22- and 29-fry (30-64%). Calanoid copepods of the genus Calanus, Paracalanus and Acartia dominated the diet (81-90%) of sea bass at different size groups. Percentage number of shooters ranged from 0.5-1.4% of total stocks and were not significantly different among treatments. The present results indicate that sea bass should spend 21 days in the hatchery prior to nursery rearing in illuminated sea cages. Sea cages are inexpensive and more cost-effective than ordinary cage or earthen pond for sea bass fingerling production.
    • Article

      Illuminating the need for ecological knowledge in economic valuation of mangroves under different management regimes - a critique 

      P Rönnbäck & JH Primavera - Ecological Economics, 2000 - Elsevier
      This is a commentary on a paper by Gilbert and Janssen (Gilbert, A.J., Janssen, R., 1998. Ecol. Econ. 25, 323–346) that deals with valuation of management alternatives for the Pagbilao mangroves, Philippines. Our main critique focuses on the undervaluation of fisheries as well as the inability to quantify the value of ecological services and internalize aquaculture's environmental costs. In addition, the sustainability criteria set up for the aquaculture management alternatives is open to debate. These weaknesses affect the result of Gilbert and Janssen's analysis so that the value of the unexploited mangrove forest is underestimated, and the value and sustainability of converting the forest into aquaculture ponds are overestimated. If applied to decision-making, the erroneous results from this partial cost–benefit analysis may have dire consequences for the mangroves and coastal communities of Pagbilao.
    • magazineArticle

      Imbao, the mangrove clam 

      RIY Adan - SEAFDEC Asian Aquaculture, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center