Now showing items 33-52 of 3272

    • Article

      Acclimation of Penaeus monodon postlarvae to fresh water 

      JB Pantastico & EN Oliveros - Fisheries Research Journal of the Philippines, 1980 - Fisheries Research Society of the Philippines
      Gradual acclimation of Penaeus monodon Fabricius to fresh water was conducted in glass aquaria and marine plywood tanks over a one-day, two-day, and three-day acclimation periods. Different stages of postlarvae were tested for their hardiness to acclimation. P35 postlarvae had a high percent survival of 98-99% while lower values were obtained for P20 and P90. A three-day acclimation period was favorable for all ages of postlarvae. Shorter durations of acclimation produced survival values as low as 20% This stress effect was apparent with P20 and P90 but not with P35 which showed high survival regardless of the length of acclimation.
    • Conference paper

      Acclimatization and stocking of fry 

      HE Dejarme - 1974
    • Article

      Accumulation and excretion of metal granules in the prawn, Penaeus monodon, exposed to water-borne copper, lead, iron and calcium 

      G Vogt & ET Quinitio - Aquatic Toxicology, 1994 - Elsevier
      Juveniles of the giant tiger prawn, Penaeus monodon, were exposed for 10 days to 1 mg/l copper, lead, iron or calcium in order to investigate the formation and accumulation of metal granules in major soft tissues as well as their excretion from the body. Metal deposition was investigated by histochemistry and electron microscopy in the hepatopancreas and surrounding organs and tissues like the stomach, midgut, anterior midgut caecum, thoracal antennal gland extensions, haematopoietic tissue, and interspersed musculature, connective tissue and pigment tissue. The abundance of metal granules varied greatly between the metals and the tissues. Iron and calcium deposits were found in none of the tissues investigated. Copper granules were accumulated in high quantity in the hepatopancreas tubules, were scarce in the antechamber of the hepatopancreas, the anterior midgut and the anterior midgut caecum, and were lacking in the other tissues. The amount and size of copper granules increased along the hepatopancreas tubules in accordance with the cells' age. The granules were released by discharge of senescent hepatopancreas cells in the antechamber region and were added to the faeces. Lead granules were primarily found in the thoracal extensions of the antennal gland. In the hepatopancreas they occurred only in very small quantities, and in the other organs and tissues they were absent. In the antennal gland, the lead granules were individually discharged into the gland lumen by apocrine secretion and excreted with the urine. The observed ability of Penaeus monodon to detoxify and remove metals like copper and lead by granule formation and excretion and to prevent other metals like iron from entrance into major soft tissues corroborate that decapods are no suitable organisms for a long-term biomonitoring of heavy metal pollution.
    • Article

      Accumulation and tissue distribution of radioiodine (131I) from algal phytoplankton by the freshwater clam Corbicula manilensis 

      MLA Cuvin-Aralar & RC Umaly - Bulletin of Environmental Contamination and Toxicology, 1991 - Springer Verlag
      Radioactive wastes discharged from establishments involved in the use of radioisotopes such as nuclear powered industries, tracer research and nuclear medicine are a potential public health hazard. Such wastes contain radionuclides, particularly Iodine-131 (131I), produced in fission with a yield of about 3%. It is a beta emitter (Bmax = 0.61MeV); it also emits gamma photons. It has a short half-life (8.04 d) (Dutton 1975), hence it is difficult to detect unless accumulated by indicator organisms.

      Radionuclides in waste waters are known to be taken up by molluscs such as mussels (Van der Borght and Van Puymbroeck 1970; Fowler et al. 1975; Hetherington et al. 1976; Helt et al. 1980; and Sombrito et al. 1982), oyster (Romeril 1971; Cranmore and Harrison 1975) and clams (Cuvin and Umaly 1988).

      This study aims to determine the uptake of 131I from algal phytoplankton (Choroococcus dispersus) fed to the freshwater clam Corbicula manillensis as well as the organ/tissue distribution. The results will be compared with our previous study on 131I uptake from water by the same clams (Cuvin and Umaly 1988).
    • Conference paper

      Acetes as prime food for Penaeus monodon larvae 

      P Kungvankij, AG Tacon, K Corre, BP Pudadera, G Taleon, E Borlongan & IO Potestas - 1986 - Asian Fisheries Society
      This paper presents research attempts to develop a suitable artificial diet for shrimp larvae with locally-available materials. Larval rearing experiments using finely ground Acetes tissues conducted under various climatic conditions and hatchery systems were completed. In the dry season, larvae in outdoor tanks fed dry Acetes had the highest survival rate (68%) compared to larvae fed Chaetoceros (48%) or fresh Acetes (39%). In contrast, larvae from an indoor hatchery reared with Chaetoceros had higher survival rate (52%) than those fed with Acetes (35%) and fresh Acetes (24%).

      During rainy months, the survival of larvae reared with Skeletonema , dry and fresh Acetes in outdoor tanks was 72%, 52% and 38% and in indoor tanks 62%, 40% and 23%, respectively.
    • Conference paper

      Acid sulfate soils and their management for brackishwater fishponds 

      VP Singh & AT Poernomo - In JV Juario, RP Ferraris & LV Benitez (Eds.), Advances in milkfish biology and culture: Proceedings of the Second International Milkfish Aquaculture Conference, 4-8 October 1983, Iloilo City, Philippines, 1984 - Published by Island Pub. House in association with the Aquaculture Dept., Southeast Asian Fisheries Development Center and the International Development Research Centre
      The major problems of fishponds build on acid sulfate soils are low pH; ionic imbalance and toxic levels of aluminum, iron, and sulfate; deficiency of phosphorus and poor response to fertilizer application; slow and poor growth of fish food organisms and fish; erosion of dikes; and in some cases fish kills. For economic operations and to remedy the problems of poor algal growth, fish kills and low yields, the acid in the pond bottom and dikes has to be neutralized or removed. A repeated sequence of drying, tilling, and flushing with seawater is a cheap, fast, and effective reclamation method that can be done in one dry season. Following this method, the dry soil pH improved; exchangeable aluminum, pyritic iron, active iron, active manganese, and sulfate decreased; and available phorphorus improved. The values for alkalinity, phosphate, aluminum, iron, and sulfate in the pond water improved greatly. Fish production was about three-fold more in reclaimed ponds (375-510 kg/ha) compared with the control ponds (50-173 kg/ha).
    • Conference paper

      Acute hepatopancreatic necrosis disease (AHPND) of penaeid shrimps: Global perspective 

      MG Bondad-Reantaso - In RV Pakingking Jr., EGT de Jesus-Ayson & BO Acosta (Eds.), Addressing Acute Hepatopancreatic Necrosis Disease (AHPND) and Other Transboundary Diseases for Improved Aquatic … Diseases for Improved Aquatic Animal Health in Southeast Asia, 22-24 February 2016, Makati City, Philippines, 2016 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The Organization for Economic Cooperation and Development (OECD) and the Food and Agriculture Organization (FAO) of the United Nations Agricultural Outlook 2015-2024 reported that fisheries production worldwide is projected to expand by 19% between the 2012-14 base period and 2024, to reach 191 million metric tons (MT) and the main driver of this increase will be aquaculture, which is expected to reach 96 million MT by 2024, 38% higher than the base period (average 2012-14) level. Among the 7 key uncertainties that affect gains in productivity, the potential of animal disease outbreaks to affect aquaculture production and subsequently domestic and international markets are once again highlighted, although for the first time in this outlook. Another milestone document, the Blue frontiers: managing the environmental costs of aquaculture identified a number of fish health issues, including increased risk of the spread of pathogens and diseases with intensification, through increased movement of aquatic animals, inter-regional trade and introduction of new species and new strains, and through the use of trash fish or live feed; concerns on residues and development of drug resistant pathogens brought about by the abuse on the use antimicrobials and other veterinary drugs; limited availability of vaccines; environmental stressors that compromise the immune system; difficulties faced by developing countries in implementing international standards; and the need for legislation, enforcement and capacity building. The issues identified then and now are almost the same.

      Addressing animal health issues in aquaculture is very challenging because the sector is highly complex (with a wide range of diversity in terms of species, systems, practices and environment, each presenting different risks), its fluid environment, and the transboundary nature where fish is considered as one of the most traded commodity, aquatic animals require more attention in order to monitor their health: they are not visible except in tank holding conditions; they live in a complex and dynamic environment and feed consumption and mortalities are hidden under water.

      This paper looks at the status of a newly emerging disease of cultured shrimp, acute hepatopancreatic necrosis disease (AHPND), which has been recognized as the most important non-viral disease threat to cultured shrimp. In particular, this paper presents the highlights of the International Technical Seminar/Workshop: EMS/AHPND: Government, Scientist and Farmer Responses held from 22-24 June 2015 in Panama City, Panama, which was organized under the auspices of an FAO inter-regional project TCP/INT/3502: Reducing and Managing the Risks of AHPND of Cultured Shrimp, being participated by 11 countries, namely: Colombia, Ecuador, Guatemala, Honduras, Mexico, Panama and Peru from Latin America and the Caribbean (LAC) region and India, Iran, the Philippines and Sri Lanka from the Asian region. The Panama EMS/AHPND June 2015 event aimed to provide a platform to improve the understanding of the disease through the lens of governments, scientists and producers and collectively generate practical management and control measures. More than 100 stakeholders from 21 countries representing the government, academe and producer sectors participated in the event. The highlights contain the latest available information at that time (June 2015) about AHPND including the current state of knowledge about the causative agent, the host and geographical distribution, detection methods, risk factors, management and actions of regional and international organizations.
    • Article

      Acute hepatopancreatic necrosis disease (AHPND) outbreaks in Penaeus vannamei and P. monodon cultured in the Philippines 

      LD de la Peña, NAR Cabillon, DD Catedral, EC Amar, RC Usero, WD Monotilla, AT Calpe, DD Fernandez & CP Saloma - Diseases of Aquatic Organisms, 2015 - Inter Research
      Acute hepatopancreatic necrosis disease (AHPND) has recently emerged as a serious disease of cultured shrimp. It has also been described as early mortality syndrome (EMS) due to mass mortalities occurring within 20 to 30 d after stocking of ponds with postlarvae. Here, Penaeus vannamei and Penaeus monodon from shrimp farms in the Philippines were examined for the toxin-producing strain of Vibrio parahaemolyticus due to AHPND-like symptoms occurring in marketable size shrimp. In the P. vannamei, histology revealed typical AHPND pathology, such as sloughing of undifferentiated cells in the hepatopancreatic tubule epithelium. Analysis using the IQ2000 AHPND/EMS Toxin 1 PCR test generated 218 bp and 432 bp amplicons confirmative of the toxin-producing strain of V. parahaemolyticus among shrimp sampled from 8 of 9 ponds. In the P. monodon, histology revealed massive sloughing of undifferentiated cells of the hepatopancreatic tubule epithelium in the absence of basophilic bacterial cells. PCR testing generated the 2 amplicons confirmatory for AHPND among shrimp sampled from 5 of 7 ponds. This study confirms the presence of AHPND in P. vannamei and P. monodon farmed in the Philippines and suggests that the disease can also impact late-stage juvenile shrimp.
    • Article

      Acute nitrite toxicity and methemoglobinemia in juvenile milkfish (Chanos chanos Forsskal) 

      JME Almendras - Aquaculture, 1987 - Elsevier
      Nitrite was about 55 times more toxic to milkfish juveniles in fresh water than in 16% brackish water: the 48-h median lethal concentrations were 12 mg NO2-N/l (95% confidence limit=7.4–19.6) and 675 mg NO2-N/l (95% confidence limit = 435.8–1,045.4) respectively. Methemoglobin levels were higher for a given concentration of nitrite in milkfish kept in fresh water than in the brackish water. Methemoglobin decreased to a normal level within 24–26 hours of the removal of nitrite.
    • Conference paper

      Acute toxicity of formalin to sea bass (Lates calcarifer) fry. 

      FC Pascual, GT Tayo & ER Cruz-Lacierda - In LM Chou, AD Munro, TJ Lam, TW Chen, LKK Cheong, JK Ding, KK Hooi, HW Khoo, VPE Phang, KF Shim & CH Tan (Eds.), The Third Asian Fisheries Forum. Proceedings of the Third Asian Fisheries Forum, 26-30 October 1992, Singapore, 1994 - Asian Fisheries Society
    • Conference paper

      Acute toxicity of mercury to Oreochromis niloticus fingerlings 

      MLA Cuvin-Aralar - BIOTROP Special Publication, 1991 - SEAMEO BIOTROP
      Fingerlings of Oreochromis niloticus were exposed to the following mercury (as HgCl2) concentrations: 0.005, 0.01, 0.02, 0.03, 0.04, 0.05 and 0.06 mg l-1 Hg of water. Hyperactivity and erratic swimming were the first indications of mercury intoxication. Scoliosis, a curvature in the mid-trunk region, was observed in some fish in the 0.03 - 0.06 mg l-1 Hg tanks. The occurrence of scoliosis is significantly correlated with mercury concentration. The 24 hour LC50 (0.0375 mg l-1 Hg) did not differ significantly with the 96 hour LC50 (0.0350 mg l-1 Hg).
    • Article

      Acute toxicity of nifurpirinol, a fish chemotherapeutant, to milkfish (Chanos chanos) fingerlings 

      CT Tamse & RQ Gacutan - Bulletin of Environmental Contamination and Toxicology, 1994 - Springer Verlag
      Nifurpirinol (trade name Furanace and originally known as P-7138), is a nitrofuran derivative synthesized by the Dainippon Pharmaceutical Co. Ltd., Japan, and was developed exclusively as a broad-spectrum antibiotic for fish and other aquatic organisms (Shimizu and Takase 1967). It has been shown to have bactericidal and fungicidal action in vitro and in vivo (Shimizu and Takase 1967; Amend and Ross 1970; Pearse et al. 1974; Mitchell and Plumb 1980), and was used because of its excellent potential in controlling prawn diseases (Delves-Broughton 1974; Gacutan and Llobrera 1977).

      Milkfish (Chanos chanos Forsskal) is a widely-reared species and a very important aquaculture food crop in most parts of Southeast Asia. Thus, it was the logical choice as test animal for investigating the LC50 toxicity levels of nifurpirinol (6-hydroxymethyl-2-[2-(5-nitro-2-furyl) vinyl] pyridine) after 96 hr exposure. Changes in the normal gill architecture of milkfish after exposure to the drug were also studied (Tamse et al., in preparation).
    • Article

      Acute toxicity of nitrite to mud crab Scylla serrata (Forsskål) larvae 

      ML Seneriches-Abiera, F Parado-Estepa & GA Gonzales - Aquaculture Research, 2007 - Blackwell Publishing
      Early larval stages of mud crab Scylla serrata were exposed to different concentrations of nitrite (40, 80 and 160 mg L−1 and a control, without added nitrite) and three salinity levels (25, 30 and 35 g L−1) using a static renewal method. No interactive effect of nitrite and salinity was detected. Estimated LT50 in 96-h toxicity tests decreased in all stages with increasing nitrite concentrations in all salinity levels. The 96-h LC50 values of nitrite-N were 41.58, 63.04, 25.54, 29.98 and 69.93 mg L−1 for zoea 1, 2, 3, 4 and 5 respectively. As the larvae grew, they showed a progressive increase in tolerance to nitrite. The toxicity of nitrite to larvae increased with exposure time. The median lethal concentration was not affected by salinity. The chloride component of salinity within 25–35 g L−1 did not seem to be as effective in alleviating toxicity as has been reported in other crustacean species. Based on 96-h LC50 and an application factor of 0.1, the ‘safe level’ of rearing mud crab larvae was calculated to be 4.16, 6.30, 2.55, 2.99 and 6.99 mg L−1 nitrite-N for zoea 1, 2, 3, 4 and 5 respectively.
    • Article

      Acute toxicity of potassium permanganate to milkfish fingerlings, Chanos chanos 

      ER Cruz & CT Tamse - Bulletin of Environmental Contamination and Toxicology, 1989 - Springer Verlag
      Potassium permanganate (KMnO4) is a strong oxidizing agent and is commonly used in aquatic systems to improve available oxygen, treat infectious diseases and parasites, detoxify fish poisons, and control algae. The following study was undertaken to determine the 24- and 96-h median lethal concentration (LC50) of milk fish (Chanos chanos)) fingerlings to KMnO4. The study was also designed to evaluate the histopathological response of fish tissues to KMnO4 but was reported in another paper (Cruz and Tamse 1986).
    • Article

      Acute toxicity of un ionized ammonia to milkfish (Chanos chanos) fingerlings 

      ER Cruz - SEAFDEC Aquaculture Department Quarterly Research Report, 1981 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings was determined using a static bioassay system. Median lethal concentrations found show that milkfish fingerlings have a high tolerance to ammonia and it is unlikely that levels as high as those employed for the acute exposure would be found to occur under natural conditions. Although the threat of acute toxicological effects induced by ammonia are remote, such conditions might be encountered in stressed natural environments or in heavily loaded aquaculture systems.
    • Article

      Acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings 

      ER Cruz - Fisheries Research Journal of the Philippines, 1981 - Fisheries Research Society of the Philippines
      The acute toxicity of un-ionized ammonia to milkfish (Chanos chanos) fingerlings was determined using a static bioassay system. The 24-, 48-, 72-, and 96-hr LC50 values were calculated at 25.74 ppm NH3-N (1.89 ppm NH3), 23.06 ppm NH3-N (1.46 ppm NH3), 21.62 ppm NH3-N (1.25 ppm NH3) and 20.65 ppm NH3-N (1.12 ppm NH3), respectively.
    • Article

      Acute toxicity of unionized ammonia to milkfish (Chanos chanos Forsskal) fry 

      NA Jumalon - SEAFDEC Aquaculture Department Quarterly Research Report, 1979 - Aquaculture Department, Southeast Asian Fisheries Development Center
    • Article

      Acute toxicity of water-accommodated fraction and chemically enhanced WAF of bunker C oil and dispersant to a microalga Tetraselmis tetrathele 

      SS Santander-Avanceña, RB Sadaba, HS Taberna Jr., GT Tayo & J Koyama - Bulletin of Environmental Contamination and Toxicology, 2016 - Springer Verlag
      This study assessed the toxicity of water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) of bunker C oil and dispersant (DISP) to a microalga, Tetraselmis tetrathele. The 72-h median effective concentration (72-h EC50) of CEWAF and DISP were determined at 3.30 % and 2.40 %, respectively. The no observed effect concentration (NOEC) of CEWAF to T. tetrathele was at 2.0 % and lowest observed effect concentration (LOEC) was at 3.0 % while NOEC and LOEC of DISP to T. tetrathele were determined at 1.0 % and 2.0 %, respectively. The addition of dispersant to oil increased the amount of total PAH present in the CEWAF test solutions. DISP alone was highly toxic, and the toxicity of CEWAF was primarily caused by the presence of dispersant.
    • Book chapter

      Adaptation of integrated fish-duck-pig farming system in Leyte 

      G Alcober - In T Bagarinao (Ed.), Research Output of the Fisheries Sector Program, 2007 - Bureau of Agricultural Research, Department of Agriculture
      Adaptation of a fish-duck-pig integrated farming system was conducted at the Busay Freshwater Experimental Farm in Babatngon, Leyte. Genetically improved farmed tilapia (GIFT) and common carp (at a ratio of 4:1) were stocked at densities of 3/m2 and 6/m2 in four earthen ponds; they were not given any commercial feed. Animal houses were built over the ponds and stocked with mallard ducks at a density of 375/ha, and piglets at 30/ha; they were given commercial feeds daily. After 154 days, the farming system produced a net yield of 1,685 kg fish/ha at a stocking density of 3/m2 and 2,808 kg/ha at 6/m2. Since water quality was not adversely affected, the higher stocking density of 6/m2 is a viable option. This farming system can be further improved and refined for better production and higher incomes.