Now showing items 561-580 of 1070

    • Article

      Initial assessment of the bacterial population of Guimaras waters and soil after the Solar I oil spill 

      C Sombito, G Lio-Po, R Sadaba & R Torreta - Philippine Journal of Natural Sciences, 2009 - University of the Philippines Visayas
      A massive oil spill occurred near the shores of Guimaras Island, Philippines in 11 Aug 2006 caused by the Sunken MT Solar I vessel. The oil spill spread to neighboring towns of Guimaras damaging the marine coastal environment, consequently,causing health and economic problems, particularly, by affecting local fisheries, wildlife and tourism. Hence, this study was conducted to assess, quantify and isolate indigenous bacteria with potential petroleum hydrocarbon-degrading properties that could be used for bioremediation of oil spill contaminated areas in Guimaras and nearby provinces.
    • Article

      Insights on the seasonal variations of reproductive features in the eastern Atlantic bluefin tuna 

      O Carnevali, F Maradonna, A Sagrati, M Candelma, F Lombardo, P Pignalosa, E Bonfanti, J Nocillado, P Palma, G Gioacchini & A Elizur - General and Comparative Endocrinology, 2019 - Elsevier
      The Atlantic Bluefin Tuna (ABFT, Thunnus thynnus) is one of the most intensely exploited fisheries resources in the world. In spite of the years of studies on ABFT, basic aspects of its reproductive biology remain uncertain. To gain insight regarding the seasonal changes of the reproductive characteristics of the eastern stock of ABFT, blood and tissue samples were collected from mature specimens caught in the Mediterranean basin during the reproductive (May-June) and non-reproductive season (Oct-Nov). Histological analysis of the gonads of May-June samples indicated that there were females which were actively spawning (contained post-ovulatory follicles) and females that were not actively spawning that had previtellogenic and fully vitellogenic oocytes. In males, testis were at early or late stage of spermatogenesis during the reproductive season. In Oct-Nov, ovaries contained mostly previtellogenic oocytes as well as β and α atretic follicles while the testis predominantly contained spermatogonia and few cysts with spermatocytes and spermatozoa. Gonadosomatic index (GSI) in females was highest among the actively spawning individuals while in males GSI was higher in early and late spermatogenic individuals compared to those that were spent. Plasma sex steroids levels varied with the reproductive season. In females, estradiol (E2), was higher in May-June while testosterone (T) and progesterone (P) did not vary. In males, E2 and T were higher in May-June while P levels were similar at the two sampling points. Circulating follicle stimulating hormone (FSH) was higher in Oct-Nov than in May-June both in males and females. Vitellogenin (VTG) was detected in plasma from both males and females during the reproductive season with levels in females significantly higher than in males. VTG was undetected in Oct-Nov samples. Since choriogenesis is an important event during follicle growth, the expression of three genes involved in vitelline envelope formation and hardening was measured and results showed significantly higher levels in ovaries in fish caught in May-June with respect to those sampled in Oct-Nov. In addition, a set of genes encoding for ion channels that are responsible for oocyte hydration and buoyancy, as well as sperm viability, were characterized at the two time points, and these were found to be more highly expressed in females during the reproductive season. Finally, the expression level of three mRNAs encoding for different lipid-binding proteins was analyzed with significantly higher levels detected in males, suggesting sex-specific expression. Our findings provide additional information on the reproductive biology of ABFT, particularly on biomarkers for the assessment of the state of maturation of the gonad, highlighting gender-specific signals and seasonal differences.
    • Article

      Intensive prawn farming in the Philippines: ecological, social, and economic implications 

      JH Primavera - AMBIO: A Journal of the Human Environment, 1991 - Springer Verlag
      The benefits of intensive farming of the giant tiger prawn Penaeus monodon in the Philippines are discussed in relation to the environmental costs. Ecological effects include mangrove conversion into ponds; use of antibiotics and chemicals leading to drug resistance; dumping of pond effluents which affect neighboring ecosystems; and pumping of groundwater that causes saltwater intrusion and vulnerability to floods. In addition, these effects lead to social costs in the form of reduction in domestic and agricultural water supplies; decreases in the production of foodfish and other food crops; further marginalization of coastal fishermen; displacement of labor; and credit monopoly by big businessmen. Comparative economic analyses of three prawn-farming systems showed that, compared to extensive and intensive culture, semi-intensive farms give the best performance using undiscounted (payback period, return on investment) and discounted (net present value, internal rate of return) economic indicators. With a 20% fluctuation in inputs or selling price intensive farming will no longer be profitable because of the high variable cost. The paper concludes with recommendations for strict enforcement of existing government guidelines (e.g. ban on mangrove conversion); institution of new policies on the use of groundwater, seawater and public credit; diversification of cultured species; and emphasis on semi-intensive farming parallel with brakes on further intensification of prawn farming.
    • Article

      Interaction between dietary levels of calcium and phosphorus on growth of juvenile shrimp, Penaeus monodon 

      VD Peñaflorida - Aquaculture, 1999 - Elsevier
      Information on the dietary phosphorus (P) requirement is essential in the formulation of a cost-effective and low-pollutant feed. Ten isonitrogenous (40% CP) casein–gelatin-based diets containing five graded levels of P (0, 0.5, 1, 1.5, 2%) for each of two levels of calcium (Ca) (0, 1.5%) were fed to juvenile Penaeus monodon previously fed a basal diet containing no P and Ca for 15 days. After 90 days, survival ranged from 70% to 87% but was not significantly different (P<0.05) among treatments. A significant Ca and P interaction was obtained in percent weight gain. Shrimp fed with diet containing 0.5% supplemental P (0.74% total P) without Ca supplementation showed a significantly higher weight gain. For total biomass of shrimp, analysis of variance showed no significant interaction between Ca and P level, but significant differences were obtained among P levels when averaged over two Ca levels. The graded levels of P did not affect shrimp whole body P (1.07–1.13%). Whole body P was not a good index in determining the P requirement of P. monodon. In the absence of Ca, 0.5% supplemental P (0.74% total P) provided maximum growth of P. monodon postlarvae. The level of Ca should be reduced in formulating diets to minimize supplemental P, thereby effecting savings in feed cost and less loss of P to the water system.
    • Article

      Interaction between test and reference populations when tilapia strains are compared by the “internal control” technique 

      ZU Basiao & RW Doyle - Aquaculture, 1990 - Elsevier
      Several strains of Oreochromis niloticus, O. mossambicus and their hybrids occur in the Philippines, and others are likely to be introduced or developed locally in the near future. Our objective was to study biological interaction. The paper reports on an experimental design in which "reference" fish are included in each replicate to provide internal statistical control.

      Growth of 10 full-sib families from each of two domestic strains was compared. A third strain of red tilapia was mass spawned to provide reference fish. Thirty equal-sized fry from each family were matched with 30 red tilapia fry and reared for 8 weeks in laboratory aquaria. The fish were deliberately crowded to provide a "worst-case scenario" for the application of the reference-strain technique. The objective was to see whether behavioural interaction causes statistical or genotype × environment interactions that create problems in the analysis.

      The test strains interacted biologically with the reference strain in different ways: the growth (change in length) of strain 1 only was negatively correlated with reference growth. Statistical interaction did occur in this extreme situation. We speculate that the reference-fish technique will be more useful in experiments in ponds or cages, where variable environmental factors induce positive, rather than negative, correlations between reference and test strains.
    • Article

      The interactive effect of some environmental factors on the growth, agar yield and quality of Gracilariopsis bailinae (Zhang et Xia) cultured in tanks 

      AQ Hurtado-Ponce & HB Pondevida - Botanica Marina, 1997 - Walter de Gruyter
      The single and interactive effects of light and temperature, salinity, and urea enrichment on the growth and agar yield and quality of Gracilariopsis bailinae were determined under indoor and outdoor tank conditions. Culture period was 6 weeks. Growth rate reached its peak on the second week in all culture conditions and gradually decreased towards the end of the culture period. Higher growth rates were obtained in seaweed cultured in outdoor (0.27-1.12% day-1) than in indoor (0.21-0.72% day-1) tanks; with urea enrichment and lower salinity levels (15-25ppt). A significant interactive effect was demonstrated between and among the environmental parameters on the growth of the seaweed. Highest gel strength (870 g cm-1) and lowest sulfate content (3.1 µg mg-1) were obtained at 25ppt, without urea enrichment and in indoor tanks. A significant interactive effect of light intensity and temperature-urea enrichment was ascertained on agar yield; also of light intensity and temperature-salinity on gel strength and sulfate content. Positive and negative correlation was likewise established between agar properties.
    • Article

      Interactive effects of vitamin C and E supplementation on growth performance, fatty acid composition and reduction of oxidative stress in juvenile Japanese flounder Paralichthys olivaceus fed dietary oxidized fish oil 

      J Gao, S Koshio, M Ishikawa, S Yokoyama & REP Mamauag - Aquaculture, 2014 - Elsevier
      A study was conducted to determine the interactive effects of vitamin C (VC) and E (VE) supplementation on growth, fatty acid composition and oxidative status of Japanese flounder juveniles. Fish (initial average body weight of 1.1 ± 0.1 g) in triplicate were fed five test diets for 60 days. Control diet contained fresh fish oil (FFO, 8.9 meq/kg) with 100 mg α-tocopherol (α-Toc) equivalents/kg of VE and 500 mg ascorbic acid (AsA) equivalents/kg of VC (FFO100E/500C). The other four diets contained oxidized fish oil (OFO, 167.8 meq/kg) with varying levels of VE (mg/kg) and VC (mg/kg) (OFO100E/500C, OFO200E/500C, OFO100E/1000C and OFO200E/1000C). Fish fed FFO100E/500C and OFO100E/500C had no differences in body weight gain (BWG). However, fish fed OFO200E/1000C diet had a significantly lower BWG than FFO100E/500C. Fish fed OFO200E/500C and OFO100E/1000C showed no differences in thiobarbituric acid-reactive substance values compared with FFO100E/500C. Increasing the levels of VC and VE supplementation increased liver AsA and α-Toc contents, respectively. Liver α-Toc content was significantly increased with incremental dietary VC levels, indicating a sparing effect of VC on liver α-Toc content of fish. Increasing the levels of dietary VC and VE supplementations decreased concentrations of 20:5n-3, 22:5n-3 and 22:6n-3 in fish liver. Fish fed OFO100E/500C and OFO200E/1000C diets showed higher oxidative stress condition than those fed FFO100E/500C. In conclusion, dietary VC and VE supplementation could maintain normal growth and health condition of juvenile Japanese flounder fed OFO. However, high doses of both vitamin supplements induced fish lipid peroxidation under oxidative stress condition.
    • Article

      International study on Artemia. XXV. Factors determining the nutritional effectiveness of Artemia: The relative impact of chlorinated hydrocarbons and essential fatty acids in San Francisco Bay and San Pablo Bay Artemia 

      P Léger, P Sorgeloos, OM Millamena & KL Simpson - Journal of Experimental Marine Biology and Ecology, 1985 - Elsevier
      Different Artemia cyst samples harvested from the San Francisco and the San Pablo Bay regions (California, U.S.A.), and suspect because of their poor nutritional performance in fish and crustacean farming, have been analysed for their chlorinated hydrocarbon and fatty acid content. These results have been correlated with survival, growth, and biomass production of larvae of the marine crustacean Mysidopsisbahia Molenock fed those different Artemia in a standard culture test. Differences in chlorinated hydrocarbon content do not correlate with differences in mysid culture performance. Fatty acid profiles reveal three groups of Artemia batches with high, intermediate, and low levels of the highly unsaturated fatty acid 20:5ω3. The production yield of the mysid larvae could be correlated with the relative level of the 20:5ω3 fatty acid in the Artemia nauplii.
    • Article

      Intertidal burrows of the air-breathing eel goby, Odontamblyopus lacepedii (Gobiidae: Amblyopinae) 

      TT Gonzales, K Masaya & A Ishimatsu - Ichthyological Research, 2008 - Ichthyological Society of Japan
      Odontamblyopus lacepedii inhabits burrows in mudflats and breathes air at the surface opening. Investigations of the intertidal burrows using resin casting demonstrated a highly branched burrow system. The burrows are composed primarily of branching patterns of interconnected tunnels and shafts that communicate into two to seven surface openings. Bulbous chambers (i.e., dilated portions of the burrow) at branching sections of the tunnels or shafts are common features of the burrow. The presence of these chambers accords the fish adequate space to maneuver inside the burrow, and thus constant access to the surface. The combination of all burrow characteristics and previously reported variability in air breathing patterns are ostensibly of selective value for aerial predator avoidance during air breathing in O. lacepedii.
    • Article

      Intestinal glucose transport in carnivorous and herbivorous marine fishes 

      RP Ferraris & GA Ahearn - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, 1983 - Springer Verlag
      The influx and transepithelial movements of glucose and their effects on the electrophysiology and Na transport in upper and lower intestines of the herbivorous surgeonfish, Acanthurus mata , and carnivorous eel, Gymnothorax undulatus , were measured. The K t G and J max G of glucose influx into the tissues were higher in the surgeonfish upper intestine than in the surgeonfish lower intestine or in both segments of the eel intestine. A prominent diffusion-like transport component was also measured in all four segments during influx experiments. Net transepithelial glucose fluxes (0.05 mM) were greater in eel intestine than in those of the surgeonfish largely due to an apparent lower apical membrane permeability of the former coincident with reduced backflux of glucose from epithelium to lumen. All four stripped intestinal segments exhibited non-significant (from zero; P >0.05) or small, serosa-negative transepithelial potential differences (-0.1 to -2.2 mV), and low transepithelial resistances (40–88 O cm -2 ). Each tissue displayed significant ( P P >0.05) change the transepithelial resistance, but did induce a significant ( P J net Na with added luminal glucose, these increased net cation fluxes were not quite significant ( P >0.05). It is concluded that coupled Na-glucose transport occurs in these tissues, but that metabolic enhancement of unrelated current-generating mechanisms also takes place and may modify depolarizing effects of organic solute transfer.
    • Article

      An investigation of enzyme and other protein polymorphisms in Japanese stocks of the tilapias Oreochromis niloticus and Tilapia zillii 

      ZU Basiao & N Taniguchi - Aquaculture, 1984 - Elsevier
      Samples of Oreochromis niloticus and Tilapia zillii were collected from the hatcheries of Osaka Prefecture Fisheries Experimental Station and Shiga Prefecture Fisheries Experimental Station, Japan, respectively. The samples were used for screening polymorphisms in 13 enzymes, skeletal muscle proteins and hemoglobins by horizontal starch gel electrophoresis. Among 35 loci examined, 12 loci for the 10 enzymes, sarcoplasmic protein and hemoglobins were polymorphic in O. niloticus and 2 loci for 2 enzymes were polymorphic in T. zillii. The observed numbers of phenotypes for respective loci agreed well with Hardy-Weinberg expectations. The genetic basis for each polymorphism is discussed. This investigation provides basis information on the status of these tilapias in Japan.
    • Article

      Investigation of some components of the greenwater system which makes it effective in the initial control of luminous bacteria 

      EA Tendencia & M dela Peña - Aquaculture, 2003 - Elsevier
      Two components of the greenwater system, the tilapia water and Chlorella, were investigated separately for their effect on the population of luminous bacteria. For the investigation of tilapia water, Tilapia hornorum was stocked at different biomasses 0, 1 and 3 kg/10 m3. Vibrio harveyi was introduced to the tanks at a final concentration of 103 cfu/ml. Luminous bacteria could not be detected in tanks stocked at 3 kg/10 m3 from day 4 to day 6, and on day 6 in tanks stocked at 1 kg/10 m3. The bacteria could still be recovered in tanks without tilapia on day 6.

      Investigation of the effect of chlorella alone on V. harveyi was undertaken using sterile flasks containing 500-ml autoclaved seawater provided with aeration. In treated flasks Chlorella was added, whereas no Chlorella was added to control flasks. No luminous bacteria were recovered on day 2 and day 3 in flasks with Chlorella, while those without the microalgae still harboured luminous bacteria at day 3.
    • Article

      Investigations on the feeding behavior of juvenile milkfish (Chanos chanos Forsskål) in brackishwater lagoons on South Tarawa, Kiribati 

      C Lückstädt & T Reiti - Verhandlungen der Gesellschaft fur Ichthyologie, 2002 - Verlag Natur und Wissenschaft
      This study evaluated the feeding behavior of the milkfish (Chanos chanos Forsskål) in extensively managed brackishwater lagoons on South Tarawa, Kiribati (Central Pacific) in August 1998. Feed intake, dietary overlap, fish condition and morphometric intestine parameters were determined. The daily ration of fish was estimated using the ”modified Bajkov model”. Fish stomach content did not differ significantly between samples from day and night, but prey preferences showed significant differences (p < 0.05). Results were compared with a data set of juvenile milkfish from the Philippines raised under similar conditions.
    • Article

      Iodine disinfection of grouper Epinephelus coioides eggs 

      EA Tendencia - Bulletin of the European Association of Fish Pathologists, 2003 - European Association of Fish Pathologists
      In this study, the developmental stage, iodine concentration and exposure time that will reduce the bacterial load without decreasing the hatching rate for the disinfection of grouper (Epinephelus coioides) egg were established. Results of the study showed that the best stage to disinfect grouper egg is at late neurula stage where the embryo shows twitching movement. The effective and safe concentration that will reduce bacterial load but will not decrease hatching rate for the disinfection of grouper egg is 7.5 ppm free iodine for 10 min. Total bacterial count of eggs disinfected with 7.5 ppm free iodine for 10 min (8.99 x 102 cfu/20 eggs) is significantly lower than the unrinsed/undisinfected eggs (1.99 x 107 cfu/20 eggs).
    • Article

      Ion chromatography of inorganic anions in brine samples 

      PF Subosa, K Kihara, S Rokushika, H Hatano, T Murayama, T Kubota & Y Hanaoka - Journal of Chromatographic Science, 1989 - Oxford University Press
      An ion chromatographic method for separating and detecting anions in brine samples is described. Nitrite, bromide, nitrate, and sulfate ions in brine samples are well separated when chloride ion concentration in the sample solution is below 2000 ppm. However, at higher chloride concentrations, nitrite and chloride peaks are not resolved. Low level nitrite ion in the brine sample is separated from a major chloride ion by a heart-cutting and recycling system. After elution, the unresolved portion, including the nitrite ion, is cut and trapped in a 10-mL sample collecting loop and reinjected on the column by using 6- and 4-port valve systems. The detection limit of nitrite spiked in the seawater samples is 0.5 ppm.
    • Article

      Ion chromatography of nitrite, bromide and nitrate ions in brine samples using a chloride-form anion-exchange resin column 

      S Rokushika, K Kihara, PF Subosa & WX Leng - Journal of Chromatography A, 1990 - Elsevier
      In aquaculture research, maintenance of water culture quality is of great importance. Recent improvement in fishpond management and fish culture systems, such as intensive feeding and fertilization, have created complex problems. Deterrioration of weter quality is primarily the resulting effect of these improvements. Foe example, high-protein feeds and nitrogen fertilizers applied in fishponds produce considerable amount of nitrate in the water. Moreover, their synergistic effects cannot be ignored. Hence the routine determination of nitrite in fishpond water is required.

      Since its introduction by Small et al., ion chromatography has been widely used for the determination of ions in water. However,the presence of very high concentrations of chloride is the main obstacles in the analysis of seawater samples, affecting the separation and detection not only of nitrite but also of other anions.

      Itoh and Shinbori applied ion chromatography to the analysis of seawater using a 125-cm long column and a conductimetric detector. This technique provided by a simple and sensitive analysial method for brine samples. However, nitrite could not be determined owing to the presence of a large chloride peak.

      Attempts to determine nitrite in seawater also led to innovations in the methodology. Lee and Field employeed a post-column cerium flourescence detection system to determine nitrite and nitrite in drinking water and seawater. The use of a pretreatment column in the silver form for removal of chloride has been reported.

      Various detectors have been applied in ion chromatography in addition to the conductimetric detector. The UV detector has been shown to be luseful detector for several kinds of inorganic anions. Selected detection of specified inorganic ions can be achieved by tuning the wavelength of the UV detector in ion chromatography and also in ion-exclusion chromatography. The elemination of the chloride matrix interference in the sub-ppm determination of nitrite in seawater was achieved by a heart-cutting and recycling method using a dual detection system consisting of conductimetric and UV detectors. This method, however, requires valve switching during analysis and needs a long analysis time.

      This paper describes a simple and rapid method of UV-absorbing anions, such as nitrite, nitrite and bromide, in brine samples using a chloride-form anion-exchange resin column combined with a UV detector.
    • Article

      Ipil-ipil leaf meal as supplemental feed for T. nilotica in cages 

      JB Pantastico & JP Baldia - Fisheries Research Journal of the Philippines, 1980 - Fisheries Research Society of the Philippines
      Tilapia nolotica fingerlings were grown to marketable size in cages in Laguna Lake at a stocking density of 150/m super(2). Those given supplemental feed of ipil-ipil leaf meal at varying levels showed faster growth compared to the control given rice bran alone. Experiments in aquaria showed that T. nilotica) can tolerate high concentrations of ipil-ipil leaf meal in feeds without showing any symptom of toxicity. Costs and returns analysis was done.
    • Article

      Isolation and cDNA cloning of somatolactin in rabbitfish (Siganus guttatus). 

      FG Ayson, ET De Jesus, Y Amemiya, S Moriyama, T Hirano & H Kawauchi - General and Comparative Endocrinology, 1999 - Academic Press
      We report the isolation and cDNA cloning of somatolactin (SL) from rabbitfish, Siganus guttatus. Rabbitfish SL was isolated from an alkaline extract of the pituitary glands by gel filtration chromatography on Sephadex G-100 and reversed-phase high-performance liquid chromatography. SL was monitored by immunoblotting with flounder SL antiserum. The preparation (yield: 0.86 mg/g wet tissues) contained two immunoreactive bands of 24 and 28 kDa on SDS-PAGE. Overlapping partial cDNA clones corresponding to teleost SLs were amplified by PCR from single-strand cDNA from pituitary glands. Excluding the poly(A) tail, rabbitfish SL cDNA is 1605 bp long. It contains a 693-bp open reading frame encoding a signal peptide of 24 amino acids (aa) and a mature protein of 207 aa. Rabbitfish SL has two possible N-glycosylation sites at positions 11 and 121 and seven half Cys residues. The deduced amino acid sequence shows over 80% identity with those of advanced teleosts like sea bream, red drum, and flounder, 76% with the salmonids, 57% with the eel, and 46% with the goldfish SL.
    • Article

      Isolation and characterization of vitellin from the ovary of Penaeus monodon 

      ET Quinitio, A Hara, K Yamauchi & A Fuji - Invertebrate Reproduction and Development, 1990 - International Society of Invertebrate Reproduction and Development
      Female-specific protein (FSP, vitellogenin) in Penaeus monodon hemolymph and its related ovarian protein (vitellin, lipovitellin) were identified and characterized using electrophoretical and immunological procedures. The purification of vitellin from mature ovaries was carried out using hydroxylapatite and Sepharose 6B columns. Results indicated that there are two proteins specifically existing in the hemolymph of the mature female which are immunologically identical to ovarian protein. These are absent in the male. The isolated vitellin has a molecular weight of approximately 540 kDa and is composed of 4 major (polypeptide) subunits, 74, 83, 104 and 168 kDa and 1 minor (polypeptide) subunit, 90 kDa. The purified protein stained positively with periodic acid-Schiff and Sudan black B and thus is a glycolipoprotein.

      Results of double immunodiffusion demonstrate the cross-reactivity of P. monodon vitellin antiserum with the ovarian extract from mature females of Penaeus indicus, Penaeus merguiensis and Penaeus semisulcatus, but not with Pandalus kessleri, indicating that there is no antigenic difference at species level in Penaeidae.
    • Article

      Isolation and cultivation of Anabaena sp. from organic media after sterilization 

      JB Pantastico, JP Baldia, SF Baldia, DM Reyes Jr. & AC Gonzal - Philippine Agriculturist, 1986 - University of the Philippines at Los Baños
      A species of Anabaena was isolated from the fronds of Azolla pinnata by combining the chopped fronds of the Azolla extract with either lake water or an organic medium (duck manure alone or combined with banana stalk) and sterilizing at 121°C and 15 psi for 20 min. Growth of Anabaena sp. was observed within 33 to 37 days and compared with the morphology of A. azollae squeezed from the fronds of Azolla pinnata. Results were discussed regarding the high temperature tolerance of the recently isolated Anabaena sp. Anabaena sp. was incubated in synthetic sponge carriers and grown in different media. The total nitrogen contributions of Anabaena sp. in lake water and in nitrogen-free inorganic medium was 22.3 and 13.2 mg/l respectively after 60 days.