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M. N. Kutty 《Marine Biology》1972,16(2):126-133
Tilapia mossambica (Peters), acclimated to and tested in fresh water at 30°C, maintained a routine respiratory quotient (R Q) of about unity and an ammonia quotient (A Q) (Vol. NH2/Vol. O2) of about 0.2 at high ambient oxygen concentrations. At low oxygen concentrations (below 2 ppm) R Q and A Q increased sharply to values of 8 and 1, respectively (at 0.6 ppm), indicating a close relationship of increase in anaerobic energy utilization and increase in protein metabolism at inadequate oxygen concentrations. T. mossambica (8 cm), exercised continuously with intervening sampling and flushing stops for 6 h, at a swimming speed of about 2 body lengths/sec, derived some anaerobic energy throughout the exercise (R Q: 1.2), utilizing more protein the longer the exercise. The coupling of the increased protein metabolism and anaerobic energy utilization may be of advantage in preventing acidosis and also in conserving sodium (Na+) in fish.Part of this work was included in a paper presented at the Centennial Meeting of The American Fisheries Society, September 13–16, 1970, New York. 相似文献
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A comparison of the efficiency of the bottom samplers used in benthic studies off Cochin 总被引:1,自引:0,他引:1
The efficiency of the van Veen and Foerst Petersen grabs used in sampling the bottom fauna near the Cochin Harbour area has been compared in two selected stations having different hydrographic and substratic conditions. The results indicate that the heavier grab is generally more efficient than a lighter one, especially when the substratum is sandy. An examination of the quantity of the sediment and the total number of species brought by the two grabs showed that the design of the van Veen is superior to the Petersen type grab used in the present study. However, due to the highly patchy distribution of the organisms the superiority of the van Veen was less evident when a comparison was made of the total number of animals sampled by the two grabs. When the distribution is bunched it is suggested that samples are drawn, as far as possible, from the same sampling position. The grabs should also be of the same weight and biting area. 相似文献
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M. N. Kutty 《Marine Biology》1969,4(3):239-242
Oxygen consumption of tagged (plastic opercular tag) and untagged mullet Liza macrolepis (Smith), forced to swim up to 22 cm/sec (fish size: 10 cm), increased proportionately to increase in swimming velocity above 5 cm/sec. The tag did not appear to cause any marked metabolic disturbance. The mean routine metabolic rate and the rate at 5 cm/sec were higher than the rates obtained for several higher levels of forced activity, possibly due to excitement and inefficient swimming at lower swimming speeds, as suggested by earlier workers. The interpretation of the elevation of a line drawn through the mean rates of metabolism at various swimming speeds, in relation to the standard metabolic rate, may be of value in quantitative expression of excitability of individual species. 相似文献
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Influence of salinity and temperature on the oxygen consumption in young juveniles of the Indian prawn Penaeus indicus 总被引:1,自引:0,他引:1
Routine oxygen consumption of very young juveniles (0.1 g) of Penaeus indicus
H. Milne Edwards was significantly influenced by ambient temperature and weight of the animal, but not by ambient salinity, when tested at salinities (7, 21, and 35) to which they had been long-term (over 10 days) acclimated. Standard oxygen consumption of young juvenile prawns (1 to 3 g), subjected to step-wise changes in ambient salinity, from sea water to low salinity waters (2 to 6), and measured after short-term (24 h) salinity acclimation at each step, was lowest at salinities where prawns such as those tested occur naturally (10 to 15). The metabolic rates do not appear to have a direct relation to the osmotic gradient, even when the influence of interfering activity is eliminated. It appears that factors other than osmotic gradient will have to be sought in order to explain the metabolic patterns of P. indicus in relation to salinity. 相似文献
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Mohammed J.K. Bashir Mohamed Hasnain Isa Shamsul Rahman Mohamed Kutty Zarizi Bin Awang Hamidi Abdul Aziz Soraya Mohajeri Izharul Haq Farooqi 《Waste management (New York, N.Y.)》2009,29(9):2534-2541
This study investigated the electrochemical oxidation of stabilized leachate from Pulau Burung semi-aerobic sanitary landfill by conducting laboratory experiments with sodium sulfate Na2SO4 (as electrolyte) and graphite carbon electrodes. The control parameters were influent COD, current density and reaction time, while the responses were BOD removal, COD removal, BOD:COD ratio, color and pH. Na2SO4 concentration was 1 g/L. Experiments were conducted based on a three-level factorial design and response surface methodology (RSM) was used to analyze the results. The optimum conditions were obtained as 1414 mg/L influent COD concentration, 79.9 mA/cm2 current density and 4 h reaction time. This resulted in 70% BOD removal, 68% COD removal, 84% color removal, 0.04 BOD/COD ratio and 9.1 pH. Electrochemical treatment using graphite carbon electrode was found to be effective in BOD, COD and color removal but was not effective in increasing the BOD/COD ratio or enhancing biodegradability of the leachate. The color intensity of the treated samples increased at low influent COD and high current density due to corrosion of electrode material. 相似文献
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Thomas Pienkowski Laur Kiik Allison Catalano Mirjam Hazenbosch Santiago Izquierdo-Tort Munib Khanyari Roshni Kutty Claudia Martins Fleur Nash Omar Saif Chris Sandbrook 《Conservation biology》2023,37(2):e14022
When deciding how to conserve biodiversity, practitioners navigate diverse missions, sometimes conflicting approaches, and uncertain trade-offs. These choices are based not only on evidence, funders’ priorities, stakeholders’ interests, and policies, but also on practitioners’ personal experiences, backgrounds, and values. Calls for greater reflexivity—an individual or group's ability to examine themselves in relation to their actions and interactions with others—have appeared in the conservation science literature. But what role does reflexivity play in conservation practice? We explored how self-reflection can shape how individuals and groups conserve nature. To provide examples of reflexivity in conservation practice, we conducted a year-long series of workshop discussions and online exchanges. During these, we examined cases from the peer-reviewed and gray literature, our own experiences, and conversations with 10 experts. Reflexivity among practitioners spanned individual and collective levels and informal and formal settings. Reflexivity also encompassed diverse themes, including practitioners’ values, emotional struggles, social identities, training, cultural backgrounds, and experiences of success and failure. Reflexive processes also have limitations, dangers, and costs. Informal and institutionalized reflexivity requires allocation of limited time and resources, can be hard to put into practice, and alone cannot solve conservation challenges. Yet, when intentionally undertaken, reflexive processes might be integrated into adaptive management cycles at multiple points, helping conservation practitioners better reach their goals. Reflexivity could also play a more transformative role in conservation by motivating practitioners to reevaluate their goals and methods entirely. Reflexivity might help the conservation movement imagine and thus work toward a better world for wildlife, people, and the conservation sector itself. 相似文献
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Wan Mohd Hafezul Wan Abdul Ghani Ahmad Abas Kutty Mohd Akmal Mahazar Salman Abdo Al-Shami Suhaila Ab Hamid 《Environmental monitoring and assessment》2018,190(5):297
In order to evaluate the water quality of one of the most polluted urban river in Malaysia, the Penchala River, performance of eight biotic indices, Biomonitoring Working Party (BMWP), BMWPThai, BMWPViet, Average Score Per Taxon (ASPT), ASPTThai, BMWPViet, Family Biotic Index (FBI), and Singapore Biotic Index (SingScore), was compared. The water quality categorization based on these biotic indices was then compared with the categorization of Malaysian Water Quality Index (WQI) derived from measurements of six water physicochemical parameters (pH, BOD, COD, NH3-N, DO, and TSS). The river was divided into four sections: upstream section (recreational area), middle stream 1 (residential area), middle stream 2 (commercial area), and downstream. Abundance and diversity of the macroinvertebrates were the highest in the upstream section (407 individual and H′?=?1.56, respectively), followed by the middle stream 1 (356 individual and H′?=?0.82). The least abundance was recorded in the downstream section (214 individual). Among all biotic indices, BMWP was the most reliable in evaluating the water quality of this urban river as their classifications were comparable to the WQI. BMWPs in this study have strong relationships with dissolved oxygen (DO) content. Our results demonstrated that the biotic indices were more sensitive towards organic pollution than the WQI. BMWP indices especially BMWPViet were the most reliable and could be adopted along with the WQI for assessment of water quality in urban rivers. 相似文献
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Keerthika Kalaiselvan Padmavathy Pandurangan Rani Velu Jeyashakila Robinson Aanand Samraj Kutty Ranjeet 《Environmental science and pollution research international》2022,29(50):75525-75538
Environmental Science and Pollution Research - Microplastics accumulation on beaches raises a serious concern worldwide. Hence, the present study was conducted with the focus of investigating the... 相似文献
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