Now showing items 73-92 of 1070

    • Article

      Cage culture of Kappaphycus alvarezii var. tambalang (Gigartinales, Rhodophyceae) 

      AQ Hurtado-Ponce - Journal of Applied Phycology, 1992 - Springer Verlag
      Kappaphycus alvarezii var. tambalang was cultured in a 3 × 3 m bamboo raft installed inside a 4 × 4 m floating net cage of Lates calcarifer (sea bass) broodstock at SEAFDEC Sub-station Igang, Guimaras, Philippines, from December 1989 to May 1990. Growth and production of K. alvarezii var. tambalang was influenced by the culture months. The highest growth rate and production were recorded in January and May, respectively, while the lowest growth rate and production were observed in March. Average growth rate (wet weight) ranged from 3.72 to 7.17% day-1, while production ranged from 575.5 to 2377 g m-1 line-1. A total production of approximately 123 t (fresh) or 37 t (dried) ha-1 in the 5-month harvest season was produced from this culture system. Cultivation ofK. alvarezii var. tambalang in cages is possible, which indicates that seaweeds can be grown with carnivorous finfish, a practice which is still untapped.
    • Article

      Cage culture of Oreochromis aureus and Oreochromis niloticus hybrids in Laguna Lake, Philippines. 

      AM Bautista, MH Carlos, BO Acosta & PB Valera - Journal of Aquaculture in the Tropics, 1988 - Taylor & Francis
      A reciprocal cross of male Oreochromis aureus and female Oreochromis niloticus were made to produce the hybrids stocked in cages in Laguna Lake, Philippines with and without feeding. The growth rates of the hybrids from the cross of female O. aureus and male O. niloticus were better than the other hybrids. From the first to the sixth culture months.

      The hybrids in terms of bulk weight per cage and percentage survival did not differ significantly. However, the average weight per fish was higher in the hybrids of O. aureus (female) x O. niloticus (male) than that of that of the original cross. The stocking density of 40/m3, supplemental feeding did not influence growth compared to the control.
    • Article

      Cage culture of the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) at different stocking densities in a shallow eutrophic lake 

      MLA Cuvin-Aralar, AG Lazartigue & EV Aralar - Aquaculture Research, 2009 - Blackwell Publishing
      Postlarvae of Litopenaeus vannamei were acclimated and stocked in lake-based cages at the following stocking densities: 10, 20, 30 and 40 shrimp m−2. Another set of shrimp was stocked in concrete tanks as reference samples at 30 shrimp m−2. Significant differences were observed among stocking densities throughout the 95-day culture. The final weight at harvest decreased with increasing stocking density: mean weights of 23.3, 15.8, 13.0, 10.9 and 14.6 g for the 10, 20, 30, 40 shrimp m−2 and reference tanks were observed respectively. There were no significant differences in survival throughout the culture period, ranging between 69% and 77%. Daily growth rates (range: 0.11–0.24 g day−1) and specific growth rates (range: 3.54–4.34%) also differed significantly among stocking densities, both increasing with decreasing stocking density. The feed conversion ratio in the cages did not differ among the stocking densities, ranging from 1.53 to 1.65. The relationship between stocking density and mean individual weight at harvest followed the equation y=81.06x−0.54 (R2=0.938) and that of stocking density and production (in g m−2) is y=58.01x−0.46 (R2=0.834).
    • Article

      Carbohydrate requirements of Penaeus monodon (Fabricius) juveniles 

      VR Alava & FP Pascual - Aquaculture, 1987 - Elsevier
      P. monodon juveniles with an initial mean weight of 0.62 g were fed isonitrogenous (45%) and isolipidic (10%) semi-purified diets containing 10, 20 and 30% trehalose, sucrose and glucose for 56 days. Shrimp fed the diet with 20% trehalose had the highest weight gain. Of the three types of sugar tested, shrimp fed diets containing trehalose and sucrose exhibited better weight gains than those fed glucose diets. A dietary sugar level of 20% resulted in the best weight gain whereas the 30% level gave the lowest weight gain.

      The survival of shrimp was also affected by the type of carbohydrate fed. Trehalose and sucrose diets promoted higher survival rates than glucose diets. The different types and levels of carbohydrates showed combined effects on the dry matter percentages of crude protein and total lipid. Trehalose and sucrose diets generally promoted increased protein deposition. Trehalose at 30% and sucrose at 20% depressed lipid content.
    • Article

      Carbohydrate, nitrogen and protein content of kinetin-treated Azolla pinnata var. imbricata plants. 

      RA Tabbada - Natural and Applied Science Bulletin, 1988 - College of Arts and Sciences, University of the Philippines
      The influence of various levels of kinetin on growth, carbohydrate, nitrogen, and protein content of Azolla pinnata var. imbricata plants cultured in a nitrogen-free 40% Hoagland’s solution under greenhouse conditions was investigated. Kinetin concentration of 0.10, 1.0 and 5.0 ppm significantly enhanced fresh matter yield during a two week period. The carbohydrate content increased in plants subjected to 0.10 and 1.0 ppm kinetin. The significant increase in the nitrogen and protein levels of whole plants grown in the presence of 0.01, 1.0 ppm kinetin would enhance its nutritive quality as fish feed. Kinetin at 10 ppm decreased yield as well as carbohydrate, nitrogen and protein content.
    • Article

      Carpospore germination and early stages of development in Gracilaria edulis (Gmelin) Silva and Gracilaria rubra Chang et Xia (Gracilariales, Rhodophyta) 

      AQ Hurtado-Ponce - The Philippine Scientist, 1993 - San Carlos Publications, University of San Carlos
      Carpospore germination and early stages of development in Gracilaria edulis and Gracilaria rubra of the Philippines are described for the first time. Both species follow the "Dumontia type" or the immediate discal type of growth. Young plants with secondary branches were observed after 17 days of germination.
    • Article

      Carrageenan properties and proximate composition of three morphotypes of Kappaphycus alvarezii Doty (Gigartinales, Rhodophyta) grown at two depths 

      AQ Hurtado-Ponce - Botanica Marina, 1995 - Walter de Gruyter
      Three morphotypes (brown, green and red) of Kappaphycus alvarezii grown at two depths were evaluated for carrageenan properties and proximate composition. The green morphotype was significantly different from the brown and red in all carrageenan properties except for sulfate content at 50 cm below the water surface; and significantly different only from the brown at 100 cm. Except for ash content and nitrogen free extract there were no significant differences in proximate composition (nitrogen, crude protein, crude fat, crude fiber) among the three morphotypes.
    • Article

      Cell growth and nutritive value of the tropical benthic diatom, Amphora sp., at varying levels of nutrients and light intensity, and different culture locations 

      MR de la Peña - Journal of Applied Phycology, 2007 - Springer Verlag
      Two series of experiments were conducted to determine suitable growth factors for the mass propagation of the local algal isolate Amphora sp. A higher growth rate of 0.2 doubling (μ) day-1 was attained at a lower photosynthetic photon flux density (PPFD; 11.4 μmol photon m-2s-1) compared to cultures exposed to higher levels of PPFD (16.1 μmol photon m-2s-1, −0.1 μ day -1; 31.3 μmol photon m-2s-1, 0.0 μ day-1). Cultures located inside the laboratory had a significantly higher cell density (133 × 104 cells cm-2) and growth rate (0.3 μ day−1) compared to those located outdoors (100 × 104 cells cm-2, 0.2 μ day-1). A comparison of nutrient medium across two locations showed that lipid content was significantly higher in cultures enriched with F/2MTM (macronutrients + trace metals) and F/2MV (macronutrients + vitamins). Saturated fatty acids were also present in high concentrations in cultures enriched with F/2M (macronutrients only). Significantly higher amounts of saturated fatty acids were observed in cultures located outdoors (33.1%) compared to those located indoors (26.6%). The protein, carbohydrates and n-6 fatty acid content of Amphora sp. were influenced by the location and enrichment of the cultures. This study has identified growth conditions for mass culture of Amphora sp. and determined biochemical composition under those culture conditions.
    • Article

      Cell growth, effect of filtrate and nutritive value of the tropical Prasinophyte Tetraselmis tetrathele (Butcher) at different phases of culture 

      MR de la Peña & CT Villegas - Aquaculture Research, 2005 - Blackwell Publishing
      A local algal isolate Tetraselmis tetrathele was studied to determine the suitable levels of three growth factors (nutrient medium, light intensity and photoperiod) for mass culture. Significantly higher population cell count (141.92 × 104) were found in 4-day-old cultures (exponential phase) enriched with Conwy medium and exposed continuously to 93.31–103.5 μmole photon m−2 s−1 light intensity compared with two other media (F, SEAFDEC/AQD) under the same light conditions. Cultures exposed to higher levels of photosynthetic photon flux density and continuous photoperiod had a significantly higher cell count regardless of nutrient media used. The chemical composition of T. tetrathele varied as the culture aged. Significantly higher crude protein (49.6%) and crude ash (15.9%) were found in cultures harvested at exponential than at stationary phase of growth. In contrast, significantly higher carbohydrate (55.2%) was noted as the culture aged. There was an increase in the percentage of saturated, monoenoic and n-3 highly unsaturated fatty acids at the stationary phase of growth. Addition of filtrate from various phases of growth and from 10-day-old cultures at various concentrations stimulated cell growth of T. tetrathele. This study identified the optimum growth conditions for mass culture of T. tetrathele and demonstrated its change in the chemical composition as the culture aged.
    • Article

      Change in Aplaya: resource use and responses to changing markets among fisherfolk in Honda Bay, Palawan 

      SV Siar - Philippine Quarterly of Culture and Society, 2003 - University of San Carlos Publications
    • Article

      Changes in mRNA expression of grouper (Epinephelus coioides) growth hormone and insulin-like growth factor I in response to nutritional status 

      FL Pedroso, EGT De Jesus-Ayson, HH Cortado, S Hyodo & FG Ayson - General and Comparative Endocrinology, 2006 - Elsevier
      Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are key links to nutritional condition and growth regulation in teleost. To understand the endocrine mechanism of growth regulation in grouper, we cloned the cDNAs for grouper GH and IGF-I and examined their mRNA expression during different nutritional status. Grouper GH cDNA is 936 base pairs (bp) long excluding the poly-A tail. It contained untranslated regions of 85 and 231bp in the 5'- and 3'-ends, respectively. It has an open reading frame of 612bp coding for a signal peptide of 17 amino acids (aa) and a mature hormone of 187aa residues. Based on the aa sequence of the mature hormone, grouper GH shows higher sequence identity (>76%) to GHs of perciforms than to GHs of cyprinids and salmonids (53-69%). Grouper preproIGF-I cDNA consisted of 558bp, which codes for 186aa. This is composed of 44aa for the signal peptide, 68aa for the mature peptide comprising B, C, A, and D domains, and 74aa for the E domain. Mature grouper IGF-I shows very high sequence identity to IGF-I of teleost fishes (84-97%) compared to advanced groups of vertebrates such as chicken, pig, and human (=<80%). Using DNA primers specific for grouper GH and IGF-I, the changes in mRNA levels of pituitary GH and hepatic IGF-I in response to starvation and refeeding were examined by a semi-quantitative RT-PCR. Significant elevation of GH mRNA level was observed after 2 weeks of food deprivation, and increased further after 3 and 4 weeks of starvation. GH mRNA level in fed-controls did not change significantly during the same period. Hepatic IGF-I mRNA level decreased significantly starting after 1 week of starvation until the 4th week. There was no significant change in IGF-I mRNA levels in fed-controls. One week of refeeding can restore the GH and IGF-I mRNA back to its normal levels. Deprivation of food for 1-4 weeks also resulted in cessation of growth and decrease in condition factor.
    • Article

      Changes in Na+, K+-ATPase activity and gill chloride cell morphology in the grouper Epinephelus coioides larvae and juveniles in response to salinity and temperature 

      NB Caberoy & GF Quinitio - Fish Physiology and Biochemistry, 2000 - Springer Verlag
      The activity of the enzyme Na+, K+-ATPase and morphological changes of gill chloride cells in grouper, Epinephelus coioides larvae and juveniles were determined 6–48 h after abrupt transfer from ambient rearing conditions (30–32 ppt, 26.5–30°C) to different salinity (8, 18, 32, 40 ppt) and temperature (25, 30°C) combinations. Na+, K+-ATPase activity in day 20 larvae did not change at salinities 8–32 ppt. Activity decreased significantly (P <0.01) after exposure to 40 ppt at 25–30°C, which was accompanied by an increase (P < 0.05) in density and fractional area of chloride cells. Enzyme activity in 40 ppt did not reach a stable level and larvae failed to recover from an osmotic imbalance that produced a low survival at 25°C and death of all larvae at 30°C. Enzyme activity and chloride cell morphology in day 40 groupers did not change in 8–40 ppt at 25°C and 8–32 ppt at 30°C. A significant decrease and a subsequent increase in Na+, K+-ATPase activity in 40 ppt at 30°C was associated with the increase in chloride cell density resulting in an increased fractional area but a decreased cell size. Enzyme activity and chloride cells of day 60 grouper were unaffected by abrupt transfer to test salinities and temperatures. These results demonstrate that grouper larvae and juveniles are efficient osmoregulators over a wide range of salinities. Salinity adaptation showed an ontogenetic shift as the larvae grew and reached the juvenile stage. This development of tolerance limits may reflect their response to actual conditions existing in the natural environment.
    • Article

      Changes in plasma osmolality and chloride concentration during abrupt transfer of milkfish (Chanos chanos) from seawater to different test salinities 

      RP Ferraris, JM Almendras & AP Jazul - Aquaculture, 1988 - Elsevier
      Milkfish juveniles (40, 120 or 260 g) were acclimated to 32 ppt seawater, then abruptly transferred to water with salinities of 0, 16, 32 (control) or 48 ppt. Blood samples were taken 0, 1, 2, 3, 5, 7 or 14 days after transfer. Survival rate was 95% or greater in all salinities. Plasma osmolality in fish exposed to salinities other than 16 or 32 ppt deviated from control values immediately after transfer but were subsequently regulated to near normal levels after several days. Although these deviations were significant, they were relatively small (≤20% of initial) as plasma osmolality changed by less than 0.07 mOsm/kg per unit change environmental salinity. Plasma chloride values generally followed the same pattern of changes as plasma osmolality. When these deviations were integrated across time, summed deviations (mOsm·day kg−1 or mEq·day l−1) were proportional to the osmotic or ionic gradient but were inversely proportional to size. For 40-g fish, summed deviations were larger in 48 than in 0 ppt; for 120- or 260-g fish, these deviations were larger in 0 than in 48 ppt. These results indicate that small milkfish tend to adapt better to fresh than to hypersaline water while larger milkfish are more likely to find hypersaline water less stressful than freshwater. Like other organ systems previously studied in milkfish, these size-dependent adaptations in osmoregulatory mechanisms reflect natural habitat shifts during development.
    • Article

      Changes in shrimp feed quality and effects on growth and survival of Penaeus monodon juveniles 

      MN Bautista & PF Subosa - Aquaculture, 1997 - Elsevier
      Five practical shrimp diets were formulated to contain 1, 10, 20, 50, and 100 g tetraethoxypropane (TEP) kg−1 diet. A diet with no added TEP served as the control. Diets were fed to Penaeus monodon (average weight 4.84 ± 0.11 g) juveniles to determine the level of fat oxidation tolerable to shrimp. Changes in shrimp feed quality were monitored by physical evaluation, thiobarbituric acid (TBA) values, fatty acid composition, and histological examination. Effects of feed quality on growth and survival of shrimp were evaluated. Results showed significant differences (P < 0.05) in TBA values among treatments. Animals fed on diet 6, which contained 100 g TEP kg−1 diet, showed signs of physical deterioration after 6–8 weeks. This diet had a significantly higher TBA value (1262 mg malonaldehyde kg−1 fat) than the other treatments. The unsaturated fatty acid content of the diet decreased as its TEP content increased. Weight gains of shrimp fed diet 5 (50 g TEP kg−1 diet) and diet 6 were significantly lower than those fed the other diets while survival was similar. Hepatopancreatic lesions were not evident in all samples. Fat oxidation levels expressed in terms of TBA values of up to 828 mg mal kg−1 fat can be tolerated by Penaeus monodon juveniles in terms of growth response.
    • Article

      Changes in the length and weight of milkfish, Chanos chanos, larvae preserved in formalin 

      S Kumagai & NM Castillo - Fisheries Research Journal of the Philippines, 1980 - Fisheries Research Society of the Philippines
      Shore-caught milkfish fry (late postlarvae) and artificially-bred, laboratory-reared larvae (0-to 20-day old) were preserved in 5% and 10% freshwater-and/or seawater-formalin solutions after measuring their initial weights and/or lengths. The changes in length and weight were observed at regular intervals.

      Shrinkage in freshwater-formalin (FWF) was less than in seawater-formalin (SWF). The difference in 5% and 10% concentrations of the same solution was not significant. Wild fry showed a final shrinkage of 5.13% of the initial length in 5% SWF and 5.0 7% in 10% SWF. Shrinkage in laboratory-reared larvae varied from 5.09-8.35% according to the age and/or developmental stage, for the same preservation period of 14 days. In estimating the natural length of milkfish larvae preserved in 5-10% SWF, a 5% shrinkage must be considered. The specimens must be kept in the preservative for at least a week before measurement since it takes at least a week for shrinkage to stabilize. Nothing definite could be said, as yet, for the weight changes in milkfish larvae.
    • Article

      Changes in the steroid hormone and vitellogenin levels during the gametogenic cycle of the giant tiger shrimp, Penaeus monodon 

      ET Quinitio, A Hara, K Yamauchi & S Nakao - Comparative Biochemistry and Physiology - Part C: Pharmacology, Toxicology and Endocrinology, 1994 - Elsevier
      The levels of estradiol-17β, and progesterone in the hemolymph, ovaries and hepatopancreas, in relation to the vitellogenin levels of captive female Penaeus monodon, were determined during the gametogenic cycle. Estradiol in the hemolymph was detected in fully mature shrimps (Stage 5) only. The ovarian estradiol levels were quite variable but showed no significant differences in the mature (Stages 4 and 5) and spent stage (Stage 6). In the hepatopancreas, a peak in estradiol level was noted in mature shrimps (Stage 5). The progesterone levels in the hemolymph were high in shrimps with mature ovaries (Stages 4 and 5) while those with immature ovaries (Stages 2, 3 and spent) were low or undetectable. The progesterone levels in both ovaries and hepatopancreas were significantly high in mature shrimps. The vitellogenin levels increased simultaneously with ovarian development and reached maximum levels during the final stage of vitellogenesis. A decrease in levels was observed after egg release. The correlation between the levels of progesterone and vitellogenin may indicate a positive effect of this steroid on vitellogenin production.
    • Article

      Changes induced in the gills of milkfish (Chanos chanos Forsskål) fingerlings after acute exposure to nifurpirinol (Furanace; P-7138) 

      CT Tamse, RQ Gacutan & AF Tamse - Bulletin of Environmental Contamination and Toxicology, 1995 - Springer Verlag
      The need for a chemotherapeutant used specifically for fish disease became increasingly apparent with intensive fish culture practices, and with the possibility of bacterial resistance against drugs used for human and animal medicine (Austin 1985). With this in mind, Nifurpirinol (trade name Furanace; P-7138) was developed by the Dainippon Pharmaceutical Co., Ltd., Japan, and is currently manufactured in the United States as Prefuran. Studies have proven that the drug is effective against bacterial and fungal pathogens in a wide variety of aquatic animals. Most of the Nifurpirinol studies done in the past have dealt on its antimicrobial activity, tissue uptake, and effective treatment levels ranging from 0.5-2.5 mg/L. The 96-hr median lethal concentration (LC50) to channel catfish (Ictalurus punctatus Rafinesque) has also been determined at 0.945-1.90 mg/L, and at 1.70 mg/L for milkfish, Chanos chanos Forsskaal. However, there have only been two studies that have examined the histological effects on treated fish. Histopathologically, Mitchell et al. (1978) found hypertrophy and hyperplasia of the lamellar epithelium in channel catfish gills exposed to 0.5 mg/L for 4 d or longer at 24 plus or minus 2 degree C, while Amend and Ross (1970) working at 21 plus or minus 1 degree C observed no apparent changes in the gills of coho salmon (Oncorhynchus kisutch) exposed intermittently to 1 mg/L of Nifurpirinol. This paper describes the histological changes observed in the gills of milkfish fingerlings used in static, 96-hr Nifurpirinol toxicity tests. Milkfish was used because of its economic importance as a widely cultured food fish in Asia. The gills were chosen as target organs.
    • Article

      Characterisation of Vibrio isolates recovered from the eyes of cage-cultured pompano (Trachinotus blochii) infested with caligid parasites (Lepeophtheirus spinifer) 

      R Pakingking Jr., NB Bautista, D Catedral & EG de Jesus-Ayson - European Association of Fish Pathologists Bulletin, 2018 - European Association of Fish Pathologists
      Exophthalmia was documented among sea cage-cultured pompano (Trachinotus blochii) broodstocks with caligid parasite (Lepeophtheirus spinifer) infestation in the Philippines. Following sequencing, and based on the results of both diagnostic investigations and infection experiments, V. harveyi likely had a role in the reported exophthalmia cases, and this was initiated by L. spinifer infection.
    • Article

      Characteristics of dehalogenase from bacteria isolated from the gut of pond-reared rohu (Labeo rohita) juveniles in Myanmar 

      E Abel, RV Pakingking Jr., G Pagador, MT Wint & F Huyop - Advances in Bioscience and Biotechnology, 2012 - Scientific Research Publishing
      Unwarranted accumulation of halogenated compounds in the rivers and streams has in recent years emerged due to the widespread use agricultural pesticides. The presence of these halogenated compounds in the water does not only suppress the immune system of fish but adversely induce serious morbidity and mortality among cultured stocks. Importantly, gradual accumulation of these compounds in the system of cultured and wild freshwater fish species cultured in ponds and floating net-cages in dams and rivers, respectively, poses some risks to humans, the end users. In this study, we attempted to isolate bacteria from the gut of pond-reared rohu (Labeo rohita) in Myanmar, screened the isolated bacteria for dehalogenase gene using molecular technique and tested the ability of these bacteria to degrade halogenated compounds in vitro. The eight bacterial strains studied were identified as Enterobacter mori strain MK-121001, Enterobacter cloacae strains MK121003, MK-121004, MK121010, Ralstonia solanacearum strain 121002, Acinetobacter baumannii strain MK121007, Chromobacterium violaceum strain MK121009 and Pantoea vagans strain 121011. Only three bacterial strains (MK121002, MK121007 and MK121009) were capable of degrading 2,2-dichloropropionic acid (2,2-DCP) as the sole carbon source up to a final substrate concentration of 20 mM. Their mean growth doubling time ranging from 6 - 23 hours with the maximum of chloride ion released of 85%. PCR amplification with oligonucleotide primers designed from group I dehalogenase revealed the presence of dehalogenase genes in all isolates suggesting dehalogenase gene in strains 121001, 121003, 121004, 121010 and 121011 were silenced. In contrast, group II dehalogenase primers did not show any PCR amplification. These results suggest that MK121002, MK121007 and MK121009 only encode a group I dehalogenase and its non-stereoselectivity is in agreement with previoulsly described group I haloacid dehalogenase. The partial gene sequences were blasted but no significant sequence identity was observed. Therefore, it suggests the 2-haloacid dehalogenase of MK121002, MK12-1007 and MK- 121009 might be a novel group I 2-haloacid dehalogenase. The results indicated a broad distribution of dehalogenation genes in many microbial genomes that harbor dehalogenase(s) due to the exposure of the microorganisms to the naturally occurring or man-made halogenated compounds in the environmental systems. So far, microorganisms capable of producing dehalogenases were mainly isolated from soil and scarcely from aquatic animals and their environments. To the authors’ knowledge, this is the first report on the isolation of dehalogenase-producing bacteria from the gut of pond-reared freshwater fish, Labeo rohita, in Myanmar.