Now showing items 3079-3098 of 3262

    • Conference paper

      Transboundary shrimp viral diseases with emphasis on white spot syndrome virus (WSSV) and taura syndrome virus (TSV) 

      LD de la Peña - In CR Lavilla-Pitogo & K Nagasawa (Eds.), Transboundary Fish Diseases in Southeast Asia: Occurence, Surveillance, Research and Training. Proceedings of … Diseases in Southeast Asia: Occurence, Surveillance, Research and Training, Manila, Philippines, 23-24 June 2004, 2004 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Crustaceans, specifically the cultured penaeid shrimp, are adversely affected by a number of diseases. Crustacean diseases that have significant social or economic impact on culture are mostly infectious in nature and many of them have no therapeutic remedies or treatments. There are currently 8 diseases of crustaceans listed by the OIE, seven of which are viral diseases of penaeid shrimp. This summary discusses two of the most important viral diseases in penaeid shrimp, white spot syndrome virus (WSSV) and Taura syndrome virus (TSV).
    • Conference paper

      Transferable drug resistance plasmids in fish-pathogenic bacteria. 

      T Aoki - In JR Arthur, CR Lavilla-Pitogo & RP Subasinghe (Eds.), Use of Chemicals in Aquaculture in Asia : Proceedings of the Meeting on the Use of Chemicals in Aquaculture in Asia 20-22 May 1996, Tigbauan, Iloilo, Philippines, 2000 - Aquaculture Department, SEAFDEC
      Chemotherapeutic agents have been developed for treating bacterial infections and have been widely used for cultured fish for the last 30 years in Japan. The extensive use of chemotherapeutants has resulted in an increase in the occurrence of drug resistance in fish-pathogenic bacteria and also in the bacterial flora of the intestinal tract of cultured fish. The kinds of chemotherapeutants used are correlated with the occurrence of the corresponding drug-resistant genes in fish-pathogenic bacteria. Almost all multiple-drug resistant strains are carried on the transferable R plasmid, although resistance in fish pathogens to nitrofuran derivatives and pyridonecarboxylic acids is associated with a chromosomal gene. The DNA sequences of R plasmids generally differ depending on the species of fish pathogen. Exceptions are the R plasmids of Aeromonas hydrophila and A. salmonicida, which have the same resistance markers as chloramphenicol, streptomycin, and sulfonamides (SA); and the R plasmids of A. hydrophila and Edwardsiella tarda, which have the same resistance markers as SA and tetracycline. The fish pathogens A. hydrophila, A. salmonicida, E. tarda, Enterococcus seriolicida, Pasteurella piscicida, and Vibrio anguillarum are all widely distributed in fish farms in various areas, and within each species the R plasmid has an identical DNA sequence. The chloramphenicol resistance (cat) gene of the R plasmid from Gram-negative bacteria was classified into CAT I, II, III, and IV according to the DNA sequence. The cat gene of P. piscicida was classified as CAT I, those of A. salmonicida and E. tarda were classified as CAT II, and that of V. anguillarum was classified as CAT II or IV, depending on the time the strains were isolated. The tetracycline-resistance determinants (Tet), which occur in six classes (Tet A through Tet G), were class D in the R plasmids obtained from strains of V. anguillarum that were isolated from 1989 to 1991. The Tet for strains of V. anguillarum isolated from 1973 to 1977 was classified as Tet B, while for strains isolated from 1980 to 1983 it was classified as Tet G.
    • magazineArticle

      Transforming a coral reef cove into mariculture hub: Igang marine station of SEAFDEC/AQD 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Fish for the People, 2015 - SEAFDEC Secretariat
    • Conference paper

      Transgenic fish and aquaculture 

      TT Chen - In TU Bagarinao & EEC Flores (Eds.), Towards sustainable aquaculture in Southeast Asia and Japan: Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia, Iloilo City, Philippines, 26-28 July, 1994, 1995 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Transgenic fish species can be routinely produced by transferring foreign DNA into developing embryos via microinjection or electroporation. This technology offers an excellent opportunity for modifying or improving the genetic traits of commercially important Fishes, mollusks, and crustaceans for aquaculture. Studies have shown that administration of recombinant fish or mammalian growth hormone (GH) to juvenile fish or oysters resulted in significant growth enhancement. Thus, it is possible to improve the growth rates of marine animals by manipulating GH or its gene. This paper reviews the results of studies to determine the efficacy of recombinant fish GH in improving the growth rates of fishes, mollusks, and crustaceans, and of gene transfer technology in producing fast-growing transgenic animals.
    • Article

      Transition from endogenous to exogenous nutrition sources in larval rabbitfish Siganus guttatus 

      H Kohno, S Hara, M Duray & A Gallego - Nippon Suisan Gakkaishi, 1988 - Japanese Society of Fisheries Science
      The early larval development of Siganus guttatus was studied with emphasis on the transition from endogenous to exogenous feeding. Three rearing trials were conducted as follows: 1) rearing in a 5 ton concrete tank at 27.9-29.3oC (T-85 trial); 2) rearing in a 0.5 ton fiberglass tank at 22.2-26.5oC (T-86A trial); 3) rearing in the same manner as in T-86A but without food (T-86B trial). On the basis of the developmental events and energy flow in T-86A trial, the early life history of the species could be divided into the following seven phases: 1) rapid larval growth due to rapid yolk resorption (from hatching to about 15 h after hatching (time after hatching: TAH)); 2) slow growth and organogenesis based mainly on yolk energy (to about 50 h TAH); 3) slow growth based on energy of yolk, oil globule and exogenous food (to about 50 h TAH); 4) slow growth based on two sources of energy, oil globule and exogenous food (to about 90 h TAH); 5) the same mode of development and energy flow as in the preceding phase, but with a certain level of feeding amount (to about 120 h TAH); 6) accelerated larval growth and effective feeding and swimming based only on exogenous food (to about 150 h TAH); and 7) the same mode as in the preceding phase with accelerated increase of feeding amount (beyond 150 h TAH). Differences in developmental mode were observed in T-85 and T-86A trials, but it could not be ascertained in this particular study which of the environment factors played the greatest influence. The results of T-86A and B showed that the larvae, in order to survive, have to get over two obstacles on feeding, that is, to start feeding and to change from endogenous to exogenous feeding suitably.
    • Conference paper

      Translocation of the clupeid Sardinella tawilis to another lake in the Philippines: A proposal and ecological considerations. 

      AC Mamaril - 2001 - Aquaculture Department, Southeast Asian Fisheries Development Center; Philippine Council for Aquatic and Marine Research and Development; Bureau of Fisheries and Aquatic Resources
      The dwindling commercial catch of Sardinella tawilis (Clupeidae), locally known as 'tawilis', reported in recent years by local fisher folk in Lake Taal, Batangas, Philippines, could be a result of the interaction of factors such as over fishing, destructive fish-capture techniques, changes in water quality, and others. Like the rest of the handful of endemic freshwater fish species in the Philippines, S. tawilis is threatened with depletion of its stocks, if not with extinction in the near future. A conservation strategy that could be considered is the translocation of 'tawilis' to another lake in the Philippines, whose ecological features closely resemble those of Lake Taal and where 'tawilis' would receive socio-economic and cultural acceptability. Cases of clupeid introductions - natural and man-made, successes and failures - are presented from published literature. Special attention is given to the case of a well-planned trans-country (Thailand-to-Indonesia) attempt to introduce a clupeid fish. The broader questions of biodiversity, endemicity, conservation, and fish community structure in Lake Taal (and elsewhere) must be underpinned by sound basic taxonomy and ecology.
    • Book chapter

      Transplantation, hatchery, and grow-out of window-pane oyster Placuna placenta in Guimaras and Iloilo 

      SS Garibay, SN Golez & AS Unggui - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      The windowpane oyster Placuna placenta (local name kapis) used to be harvested in large quantities and support a shellcraft industry in the Philippines, particularly in Panay Island. But the fishery and the industry declined markedly by the 1990s. Studies were conducted to transplant kapis and also to develop hatchery techniques for it in an effort to counter the population depletion. Kapis with average shell heights of 7 cm and 10 cm were transplanted from Roxas City in northern Panay Island and from Oton, Iloilo in southern Panay to Taklong Island in Guimaras during the rainy season (July–November) and the dry season (February–June). Survival of the transplants was higher during the dry season (57–60%) than during the rains (35–48%). Sexually mature kapis 10 cm in shell height were induced to spawn by temperature manipulation, water level manipulation, and use of ultravioletirradiated sea water. Spawning was successfully induced by raising the water temperature to 29±0.5oC. Eggs measured 45 μm on average, and fecundity was 5,000–10,000 per female. Kapis larvae were reared on a combination of the microalgae Isochrysis galbana, Tetraselmis sp., and Chaetoceros calcitrans, maintained at a density of 100,000 cells/ml. Three water treatment schemes were tested for larval rearing: chlorination, ultraviolet irradiation, and filtration (control). Larvae survived to the umbo veliger stage (180 μm, day 10) in chlorinated sea water whereas mass mortality occurred at the straight-hinge stage (days 4–) in both UV-treated and filtered sea water.
    • Article

      Transport of hatchery-reared and wild grouper larvae, Epinephelus sp. 

      CB Estudillo & MN Duray - Aquaculture, 2003 - Elsevier
      Optimum packing conditions for the transport of hatchery-reared and wild grouper larvae were investigated under simulated condition or actual air transport. Simulation of transport motion was done through the use of an electric orbit shaker to identify the best packing conditions for the transport of grouper larvae at various ages. Simulated transport was conducted in hatchery-reared grouper larvae at day 35 (mean TL=14.73 mm), 45 (mean TL=15.23 mm) and 60 (mean TL=28.16 mm) at packing densities of 50, 100 and 200 larvae l−1 and at high (28 °C) or low (23 °C) temperatures. Packing density of 50 larvae l−1 was best for 45- and 60-day-old larvae 8 h transport at low temperature. However, packing density could be increased to a maximum of 100 larvae l−1 8 h transport at 23 °C with mortality rates ranging from 2.3% to 5.3%. The increase in total NH3 level was dependent on temperature, packing density and size of larvae. High packing density (100–200 larvae l−1) and temperature (28 °C) resulted in increased NH3 level and mortality rates during transport. In addition, regardless of the temperature, NH3 levels were consistently higher for 60-day-old larvae. Day-60 grouper larvae displayed strong resistance to handling/mechanical stress compared to 35-day-old larvae probably because most are already fully metamorphosed at this stage. Based on these results, a packing density of 50 larvae l−1, a temperature of 23 °C and larval age of 60 days were considered as the best transport conditions for hatchery-reared grouper larvae. When these transport conditions were used in experiment 2, for 26-day-old hormone-metamorphosed, 60-day-old naturally metamorphosed or 60-day-old pre-metamorphosing hatchery-reared grouper larvae, a 100% survival rate was attained in all treatments. Seven days of hormone (T3) treatment did not accelerate metamorphosis of wild-caught transparent grouper larvae (tinies) significantly. Survival rates of hormone-treated transparent tinies (H-tinies), untreated black tinies (B-tinies) and untreated transparent tinies (T-tinies) were also similar after 8–9 h air transport (experiment 3). The results of the current study suggest that T3 treatment did not affect the performance of hatchery-reared and wild-caught transparent tinies/larvae during transport. In addition, mass mortalities of these transported tinies during the nursery phase were associated with nutritional aspect and the sudden confinement of these undomesticated wild-caught grouper to small space rather than transport or hormone treatment effects.
    • Article

      Transport of Scylla serrata megalopae at various densities and durations 

      ET Quinito & FD Parado-Estepa - Aquaculture, 2000 - Elsevier
      The optimal conditions for transport of Scylla serrata megalopae were determined. Loading densities of 50, 100 and 150 ind l−1 of hatchery-reared megalopae were studied over a 6-h simulated transport, including shaking. Survival immediately after transport was significantly higher at 50 ind l−1 (99.3±1.6%) (mean±x%) than at 100 (93.0±5.0) and 150 ind l−1 (94.0±3.8%). The same trend was noted 15 h after transport. Another experiment compared survival of megalopae packed at 50 and 100 ind l−1 with simulated transport of various durations (3, 6, and 9 h) at mobile and stationary conditions. Regardless of the duration and condition of transport, survival was again significantly higher at 50 ind l−1 (86.7±2.4%) compared to 100 ind l−1 (79.7±2.1%). Megalopae that were shaken or remained unshaken for 3 or 6 h had similar survival through transport as those shaken for 9 h. Megalopae that remained unshaken for 9 h gave the lowest survival among treatment groups (38.7±0.2%).

      Due to cannibalistic behavior, stationary transport conditions may have provided the megalopae with a chance to grasp each other. In a third experiment, a batch of megalopae was packed at water temperature levels of 20, 24, and 28°C (ambient) at 50 and 100 ind l−1 for 6 h simulated transport, including shaking. Density and temperature separately influenced survival. Survival was lower at 28°C than 24°C. Although megalopae were less active at 20°C, survival was similar to that at 24°C and 28°C. These results provide useful information for megalopae transport from hatchery to ponds.
    • Article

      Transport of sugpo, Penaeus monodon juveniles 

      W Yap, H Mochizuki & F Apud - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Book chapter

      Treatment of shrimp pond effluents by sedimentation and by seaweed and mussel biofiltration 

      NR Fortes & VL Corre Jr. - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      Tiger shrimp Penaeus monodon were stocked in three 1,000 m2 ponds at 12,000 juveniles/pond and grown for 141 days. Water quality in the ponds was monitored over the grow-out period, particularly before and after every water change. BOD, chlorophyll a, and total dissolved solids of the effluent increased over the grow-out period due to increased biomass and feed input. Similar trends were observed for inorganic nitrogen, reactive phosphorus, total suspended solids, and hydrogen sulfide. Concentrations decreased after draining and reflooding. Soil samples also showed increases in organic matter available phosphate, carbon, and nitrogen content over the grow-out period.

      Effluents from semi-intensive shrimp ponds were discharged into eight treatment ponds (each 200 m2): three sedimentation ponds, three with Gracilaria stocked at 20 kg/pond, and two with mussels stocked at 10/m2. Measurements were made of pH, ammonia, nitrite, nitrate, reactive phosphorus, biochemical oxygen demand, chlorophyll a, total suspended solids, and total dissolved solids in the water in the treatment ponds after effluent addition, one week and two weeks later, and before draining. Soil pH, organic matter, and phosphorus were also analyzed every two weeks. The changes in these variables were similar among the three treatments in the eight ponds. In this study, water quality of effluents improved after one week in the treatment ponds.
    • magazineArticle

      Trochus: the mollusc for buttons 

      MB Surtida - SEAFDEC Asian Aquaculture, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Tropical abalone culture in Philippines 

      AC Fermin - Global Aquaculture Advocate, 2001 - Global Aquaculture Alliance
    • Book chapter

      Tropical shrimp farming and its sustainability 

      JH Primavera - In SS De Silva (Ed.), Tropical Mariculture, 1998 - Academic Press
      In December 1996, the Supreme Court of India ordered the closure of all semi-intensive and intensive shrimp farms within 500 m of the high tide line, banned shrimp farms from all public lands, and required farms that closed down to compensate their workers with 6 years of wages in a move to protect the environment and prevent the dislocation of local people. If the 1988 collapse of farms across Taiwan provided evidence of the environmental unsustainability of modern shrimp aquaculture, the landmark decision of India's highest court focused attention on its socioeconomic costs.

      This chapter briefly describes shrimp farming, discusses its ecological and socioeconomic impacts and recommends measures to achieve long-term sustainability including improved farm management, integrated coastal zone management, mangrove conservation and rehabiUtation, and regulatory mechanisms and policy instruments.
    • magazineArticle

      The trouble with antibiotics and pesticides is... 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1996 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The paper discusses the output of the meeting on the use of chemicals in aquaculture in Asia. The effects of chemical use on cultured stocks in the farm, the immediate environment through discharges and effluents, surrounding areas, farm staff, consumers and drug resistance organisms are also discussed. It also shows how an antibiotic-resistant microorganism develops as the result of indiscriminate use of antibiotics.
    • Article

      Tryptophan requirement of juvenile Asian sea bass Lates calcarifer 

      RM Coloso, DP Murillo-Gurrea, IG Borlongan & MR Catacutan - Journal of Applied Ichthyology, 2004 - Blackwell Publishing
      The dietary requirement of tryptophan for juvenile Asian sea bass (Lates calcarifer Bloch) was studied. The juveniles (mean initial weight, 5.30 ± 0.06 g) were given semi-purified test diets containing fish meal, gelatin, squid meal, and crystalline amino acids, for 12 weeks. Each set of isonitrogenous and isocaloric test diets contained graded levels of tryptophan. Fish (15 per tank) were reared in 250-L fiberglass tanks provided with continuous flow-through sea water at 26°C and salinity of 28 p.p.t. Fish were fed twice daily at a feeding rate of 8% of the body weight day−1 for the first 4 weeks and at 3.5–2.5% of the body weight day−1 from 5 to 12 weeks. The experiment was in a completely randomized design with two replicates per treatment. Mean percentage weight gains and feed efficiency ratios were significantly different in fish fed varying tryptophan levels. Survival was 100% in all treatments. On the basis of break-point analysis of the growth response, the dietary tryptophan requirement of juvenile Asian sea bass is 0.41% of the dietary protein. This information will be useful in further refinement of practical feed formulations for the Asian sea bass.
    • magazineArticle

      Tubigon: CRM in progress 

      NJ Dagoon - SEAFDEC Asian Aquaculture, 1999 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • magazineArticle

      Tuna fishermen: How they fish 

      Southeast Asian Fisheries Development Center, Aquaculture Department - Aqua Farm News, 1993 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Book chapter

      The tuna fishery off northwestern Luzon: catch of purse seines and hand lines operating around fish-aggregating 'payaw' 

      VV Prado - In TU Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      The tuna fishery along northwestern Luzon was studied from March 1994 to April 1995. About 120 units of fish aggregating ‘payaw’ were set 20–100 km offshore and fished by about 350 handline boats and 6 purse seines. The handline landing areas were in Apatot, San Esteban, Ilocos Sur and in Darigayos Cove, La Union. The resident purse seine was based at Poro Point in San Fernando, La Union; the others were occasional operators. Skipjack tuna Katsuwonus pelamis was the primary species landed by the purse seine and yellowfin tuna Thunnus albacares was mostly landed by the hand lines. These species occurred year-round with peaks during the dry season. The purse seine was operated about 9 sets per month, and landed an average of 51 mt fish monthly (catch rate 5.7 mt/set), highest in November, December and March. Handline fishing was carried out an average of 17 days a month (catch rate about 19 kg/boat-day). The tuna fishery was adversely affected by strong monsoon winds and typhoons. The rough seas inhibit fishing and give the tuna populations much needed respite from the intense fishing pressure.
    • magazineArticle

      Tuna markets and farming: Japan and Australia 

      E Gasataya - SEAFDEC Asian Aquaculture, 2000 - Aquaculture Department, Southeast Asian Fisheries Development Center