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Food web structure and energy flow in open water of ponds
1990
Korinek, V. (Karlova Univ., Prague (Czech Republic). Dept. of Parasitology and Hydrobiology)
Natural food evaluation and water quality in zero water exchange culture of Litopenaeus vannamei fertilized with wheat bran Полный текст
2009
Campos, Susmara Silva | Silva, Ugo Lima | Lúcio, Maria Zita Tabosa | Correia, Eudes de Souza
The aim of this study was to analyze the influence of organic fertilizer on the availability of natural food (plankton and benthos) and water quality. Two fertilization protocols were adopted using inorganic and organic fertilizers with shrimp (stocked treatment) and their controls (unstocked treatment). Experimental units consisted of 12 circular fiberglass tanks (500 l) with estuarine sediment, individual aeration and no water exchange. In stocked treatments were used 40 juveniles/m², and they were fed with 35% crude protein marine shrimp ration, three times a day. Under the organic fertilization protocol, the plankton showed higher abundance of Nitzschia and rotifers, the phytobenthos consisted mainly of Nitzschia, Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. In relation to inorganic fertilization, the plankton was represented mainly by Coscinodiscus and rotifers, the phytobenthos consisted mainly of Amphiprora and Oscillatoria, the epibenthos was represented mainly by nematodes and rotifers, and the macro-invertebrates were mainly oligochaetes. Dissolved oxygen was higher for organic fertilizer (6.16 ± 0.98 mg/l) than for inorganic (5.92 ± 1.19 mg/l) while the other water quality parameters did not present significant differences. Survival was similar in the two fertilization regimes (96.6%). Final body weight was 11.89 ± 1.73 g for the inorganic fertilizers and 12.28 ± 1.71 g for organic fertilizer. It is concluded that wheat bran showed good performance in the water quality without exchange, in the availability of natural food, and in the growth and survival of the shrimps in the microcosms.
Показать больше [+] Меньше [-]Salmonids in the water source reservoirs [in Czechoslovakia] - their importance and food
1987
Hochman, I. (Ustav Rybarstva a Hydrobiologie, Bratislava (Czechoslovakia)) | Sukop, I.
Comportamento alimentar e qualidade da água em tanques de criação de girinos de rã-touro Lithobates catesbeianus = Feeding behavior and water quality in tanks containing bullfrog tadpoles Lithobates catesbeianus Полный текст
2008
Lúcia Helena Sipaúba-Tavares | Joceli Cristina Leite de Morais | Marta Verardino De Stéfani
O objetivo deste trabalho foi avaliar o comportamento alimentar e a qualidade da água em tanques de criação de girinos de rã-touro Lithobates catesbeianus durante 56 dias, a partir do estágio 25 da Tabela de Gosner (1960), criados em tanques de alvenaria comcapacidade de 1000 L. Os girinos que receberam ração (R) e alga + plâncton + ração (APR) apresentaram o melhor peso e sobrevivência, diferindo significativamente (p < 0,05) dos outros tratamentos (somente alga e alga + plâncton). As variáveis físico-químicas da águadiferiram significativamente (p < 0,05) durante o período experimental e entre os tratamentos. Foi observada uma relação entre alimento fornecido e aqueles contidos no trato digestório dos girinos (rs = 0,39; p < 0,05). A partir de 14 dias, houve mudança nohábito alimentar dos girinos procurando outros itens alimentares além do plâncton. A utilização de dietas naturais quando combinadas com dieta artificial (ração) proporcionou desenvolvimento satisfatório aos girinos.<br><br>The objective of this study was to evaluate the effect of food treatments and water quality on the development of bullfrog tadpoles. The analysis, carried out in 1000 L tanks, was undertaken by weight and survival rates, during 56 days, as from stage 25 (Gosner, 1960). Treatments with ration (R) and algae + plankton + ration (APR) had the best results in weight and survival rates, which were significantly different (p < 0.05) from the other treatments, comprised of algae only or algae + plankton. Physical and chemical variables of water differed significantly (p < 0.05) during the experimental period and among treatments. There was a correlation between the concentration of species present in the food and in the tadpole digestive tract (rs = 0.39; p < 0.05). From the 14th dayof age, bullfrog tadpoles changed their feeding behavior, or rather, a search for food items other than plankton occurred. The utilization of combined natural and artificial (ration) diets to feed bullfrog tadpoles was feasible and yielded a satisfactory development in theanimals.
Показать больше [+] Меньше [-]Some relations among the fish stock, water quality and amount of natural food in ponds
1990
Prikryl, I. (Research Inst. of Fish Culture and Hydrobiology, Vodnany (Czech Republic))
An effect of irrigation and cultivation system on food chain in paddy water environment: A study on availability of stable isotope ratios approach to examine paddy water ecosystem
2005
Konagaya, S.(Ibaraki Univ., Ami (Japan)) | Kobayashi, H.
For the purpose of examining on role of irrigation and cultivation system to paddy ecosystem, we study species and number of Odonata larvae and analyze the stable isotope ratios of the Odonata larvae and the plankton/detritus in water of paddy fields and irrigation ponds. As a results, cultivation system clearly effects to composition of species and number of Odonata larvae. delta sup(13)C indicates that Orthetrum albistylum speciosum larvae and Coenagrionidae spp. larvae which are dominant species in paddy water, depend on specified food sources, each other. delta sup(15)N shows that the trophic level of Odonata larvae is higher than that of the plankton/detritus in paddy water. It is considered that analyze the stable isotope ratios application is effective to examine water ecosystem and food web in paddy.
Показать больше [+] Меньше [-]Young agriculturists [Christopher Cruz of Hagonoy, Bulacan and Ace Limpin of San Fernando City, Pampanga, Philippines] use Nova Pure PCM Agua [a product of Novatech Agri-Food Industries, bio-organic fertilizer] for lablab production
2008
Pablico, S.Ma.
Control of Listeria innocua Biofilms on Food Contact Surfaces with Slightly Acidic Electrolyzed Water and the Risk of Biofilm Cells Transfer to Duck Meat Полный текст
2018
Jeon, Hye Ri | Kwon, Mi Jin | Yoon, Ki Sun
Biofilm formation on food contact surfaces is a potential hazard leading to cross-contamination during food processing. We investigated Listeria innocua biofilm formation on various food contact surfaces and compared the washing effect of slightly acidic electrolyzed water (SAEW) at 30, 50, 70, and 120 ppm with that of 200 ppm of sodium hypochlorite (NaClO) on biofilm cells. The risk of L. innocua biofilm transfer and growth on food at retail markets was also investigated. The viability of biofilms that formed on food contact surfaces and then transferred cells to duck meat was confirmed by fluorescence microscopy. L. innocua biofilm formation was greatest on rubber, followed by polypropylene, glass, and stainless steel. Regardless of sanitizer type, washing removed biofilms from polypropylene and stainless steel better than from rubber and glass. Among the various SAEW concentrations, washing with 70 ppm of SAEW for 5 min significantly reduced L. innocua biofilms on food contact surfaces during food processing. Efficiency of transfer of L. innocua biofilm cells was the highest on polypropylene and lowest on stainless steel. The transferred biofilm cells grew to the maximum population density, and the lag time of transferred biofilm cells was longer than that of planktonic cells. The biofilm cells that transferred to duck meat coexisted with live, injured, and dead cells, which indicates that effective washing is essential to remove biofilm on food contact surfaces during food processing to reduce the risk of foodborne disease outbreaks.
Показать больше [+] Меньше [-]Non-proportional bioaccumulation of trace metals and metalloids in the planktonic food web of two Singapore coastal marine inlets with contrasting water residence times Полный текст
2016
Calbet, Albert | Schmoker, Claire | Russo, Francesca | Trottet, Aurore | Mahjoub, Mohamed-Sofiane | Larsen, Ole | Tong, Hor Yee | Drillet, Guillaume | National Parks Board (Singapore) | Nanyang Technological University | Danish Council for Independent Research | Ministerio de Economía y Competitividad (España)
11 pages, 5 figures, 5 tables, 1 appendix supplementary data https://dx.doi.org/10.1016/j.scitotenv.2016.03.234.-- This work is a contribution to the consolidated research group 2014 SGR 498 of the Generalitat de Catalunya | We analyzed the concentrations of trace metals/metalloids (TMs) in the water, sediment and plankton of two semi-enclosed marine coastal inlets located north of Jurong Island and separated by a causeway (SW Singapore; May 2012-April 2013). The west side of the causeway (west station) has residence times of approximately one year, and the east side of the causeway (east station) has residence times of one month. The concentrations of most of the TMs in water and sediment were higher in the west than in the east station. In the water column, most of the TMs were homogeneously distributed or had higher concentrations at the surface. Preliminary evidence suggests that the TMs are primarily derived from aerosol depositions from oil combustion and industry. Analyses of TMs in seston (>. 0.7 μm; mostly phytoplankton) and zooplankton (>. 100 μm) revealed that the seston from the west station had higher concentrations of most TMs; however, the concentrations of TMs in zooplankton were similar at the two stations. Despite the high levels of TMs in water, sediment and seston, the bioaccumulation detected in zooplankton was moderate, suggesting either the presence of effective detoxification mechanisms or/and the inefficient transfer of TMs from primary producers to higher trophic levels as a result of the complexity of marine planktonic food webs. In summary, the TM concentrations in water and seston are not reliable indicators of the bioaccumulation at higher trophic levels of the food web | This work was funded through grant MadeInPlankton from Singapore National Parks Board - Singapore (NParks) and DHI-NTU Research Centre and Education Hub, Ung EliteForsk grants 10-093759 and 10-094773 from the Danish Ministry for Independent Research to GD, and Projects PROTOS (CTM2009-08783), TOPCOP (CTM2011-23480) and FERMI (CGL2014-59227-R) from the Spanish Ministry of Economy and Competitiveness to AC | Peer Reviewed
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