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排序方式: 共有190条查询结果,搜索用时 0 毫秒
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Pollyanna de Moraes Frana Ferreira Lidiane da Silva Nascimento Devlynn Coelho Dias Diogo Magalhes da Veiga Moreira Ana Lúcia Salaro Mariella Bontempo Duca de Freitas Antonio Policarpo Souza Carneiro Jener Alexandre Sampaio Zuanon 《Journal of the World Aquaculture Society》2014,45(1):28-34
This study aimed to evaluate the potential of oregano oil as a growth promoter for the yellowtail tetra, Astyanax altiparanae. The fish (1.46 ± 0.09 g) were distributed into twenty‐four 60‐L aquaria at a stocking density of 0.5 fish/L. Six isonitrogenous (350 g crude protein/kg) and isocaloric (4272 kcal gross energy/kg) diets containing 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 g/kg of oregano oil were evaluated. At the end of 90 d there was a quadratic effect of oregano oil levels for weight gain, specific growth rate, protein efficiency ratio and carcass weight, and the estimated values to maximize these variables were between 0.2 and 0.6 g/kg. There was also a quadratic effect on the feed conversion ratio, and the estimated value to improve this variable was 0.62 g/kg. A positive linear effect of the treatments was observed for muscle glycogen. With increased levels of oregano oil in the diet, there was a reduction in dry matter and ether extract and an increase in the protein content of the carcass. Thus, it can be concluded that oregano oil, at the level of 0.5 g/kg, acts as a growth promoter for A. altiparanae by improving growth performance and carcass composition. 相似文献
95.
Rafael Soriani Medeiros Bianca Azevedo Lopez Luís André Sampaio Luis Alberto Romano Ricardo Vieira Rodrigues 《Aquaculture International》2016,24(4):985-993
False clownfish, Amphiprion ocellaris, is one of the most commercialized fish species in the world, highly produced to supply the aquarium market. The high stocking densities used to maximize fish production can increase ammonia and nitrite to toxic levels. In this study, A. ocellaris juveniles (1.20 ± 0.34 g) were exposed to six concentrations of ammonia ranged from 0.23 to 1.63 mg/L NH3-N and eight concentrations of nitrite (26.3–202.2 mg/L NO2 ?-N). The LC50- 24, LC50-48, LC50-72 and LC50-96 h were estimated to be 1.06, 0.83, 0.75 and 0.75 mg/L for NH3-N and 188.3, 151.01, 124.1 and 108.8 mg/L for NO2 ?-N. Analysis of gill lesions caused by sublethal concentrations of these nitrogenous compounds showed that both nitrogenous compounds induced tissue lesions such as hyperplasia of epithelium cells, hypertrophy of chloride cells and lamellar lifting to all concentrations tested. However, histopathological alterations were more conspicuous accordingly the increase of ammonia or nitrite in fish exposed to 0.57 mg/L NH3-N or 100 mg/L NO2 ?-N. Based on our results, we recommend to avoid concentrations higher than 0.57 mg/L of NH3-N and 25 mg/L of NO2-N in water. 相似文献
96.
Ricardo Vieira Rodrigues Janaína dos Santos Pedron Luis Alberto Romano Marcelo Borges Tesser Luís André Sampaio 《Aquaculture Research》2015,46(5):1241-1247
Fish are potentially submitted to water acidification when reared in recirculating aquaculture systems. This study evaluated the responses of juvenile cobia Rachycentron canadum after acute exposure to acid water. Juvenile cobia (12.6 ± 0.5 g; 14.2 ± 0.2 cm) were acutely exposed to four pH levels (7.9 (control), 6.5, 6.0, and 5.5). After 24 h of exposure to different pH values, fish were sampled for physiological and histopathological evaluation. Acid water affected physiological parameters and induced morphological histopathologies on gill and skin of juvenile cobia, and these effects were more conspicuous with decreasing pH values. Acid stress induced blood acidosis in juvenile cobia, coupled to a decrease in bicarbonate (HCO3?) and saturated O2 (sO2) in fish blood. On the other hand, haematocrit, haemoglobin and glucose concentration increased their values (P < 0.01) comparing to control level. Hyperplasia with completely fusion of secondary lamella was observed in all pH treatments (6.5. 6.0 and 5.5), while telangiectasia and proliferation of chloride cells were present for fish exposed to pH 6.0 and 5.5. In skin hyperplasia and hypertrophy of mucous cells, necrosis of these cells for fish exposed to pH 6.0 and 5.5 was observed. The results of this study demonstrate that acute acid water exposition affected physiology and histopathology in juvenile cobia, especially at pH values below 6.5. Accordingly, particular attention must be given to pH during cobia reared in recirculating aquaculture. 相似文献
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98.
M. Angélica Garrido‐Pereira André Luiz Braga Andréa Ferretto da Rocha Luís André Sampaio Paulo César Abreu 《Aquaculture Research》2013,44(2):261-267
Effects of ultraviolet radiation (UV) on probiotic bacteria (Bacillus subtilis and B. licheniformis) were tested in two experiments, with the following treatments: (i) UV treatment – using fluorescent and UV‐lamps and (ii) Control – CTRL, using fluorescent lamps. Bacterial abundance and respiration were evaluated every 24 h for 3 days for Experiment 1, and at 0, 6 and 24 h for Experiment 2. In the Experiment 1, total UV dose was 4 336.41 mW cm?2. UV treatment presented small respiration rates only on day 3, while in the CTRL oxygen consumption was always high. On all days, the abundance of the Bacilli exposed to UV was significantly smaller than that of the CTRL. The second experiment, with total UV dose of 1 445.47 mW cm?2, presented oxygen consumption in the UV treatment only during the first 6 h. In the CTRL, oxygen consumption increased from the beginning due to the bigger abundance Bacilli cells. Small coccus‐shaped bacteria ocurred in the UV treatment of both experiments. It may be concluded that exposure to UV, normally used for water disinfection, can inactivate probiotic bacteria. 相似文献
99.
Maria Inez Espagnoli Geraldo Martins Giovani Sampaio Gonçalves Rose Meire Vidotti 《Journal Of Aquatic Food Product Technology》2013,22(8):1202-1212
ABSTRACTThis study evaluates the feasibility of producing hamburger, silage, and leather using fish by-products in a medium-sized recovery plant with total capacity of processing up to 1,000 kg/day of whole fish. The average volume of fish by-products generated daily was 673 kg. The investment necessary to introduce these three technologies was US$47,193.13 in 1 year. The average cost to produce 1 kg of hamburger, silage, and leather was 1.24, 0.17, and US$1.77, respectively. The return of the investment was 56.16%, and the net present value US$570,582.16. The investment pay back was realized in 3.88 years, with a benefit/cost relationship of 1.31. For all the studied scenarios, sale price variations most influenced the economical parameters analyzed. 相似文献