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81.
82.
以16种植物和3种动物提取物作为实验材料,以体长为3—5cm的锦鲤为实验对象,采用触球法进行诱食活性研究,5次重复试验,并利用SPSS软件进行分析。结果表明,大蒜、浒苔、洋葱、西红柿、江蓠、陈皮、橙子、山楂、紫菜提取物和海星、海蜇、牡蛎提取物对锦鲤显示出诱食反应。其中,大蒜P=0.0010.05、浒苔P=0.0020.05、江蓠P=0.0040.05、陈皮P=0.0370.05、海星P=0.0030.05,说明大蒜、浒苔、江蓠、陈皮、海星对锦鲤的诱食反应有显著意义。 相似文献
83.
Russian Journal of Ecology - 相似文献
84.
以静水法生物测试研究了对二氯苯和镉对草鱼(Ctenopharyngodon idellus)的联合毒性效应,并采用Marking水生毒理联合毒性相加指数法对联合毒性效应进行了评价.结果表明, 对二氯苯和镉对草鱼的单一毒性作用时,24、48、72和96 h对二氯苯对草鱼的LC50分别是10.11、9.04、8.52和7.83 mg/L; 24、48、72和96 h镉对草鱼的LC50分别是40.02、35.05、28.99和24.41 mg/L,因此对二氯苯的毒性大于镉的毒性. 对二氯苯和镉对草鱼种的联合毒性作用,当采用毒性1∶1进行试验时,暴露时间分别为24、48、72、96 h时AI>0,联合作用结果为协同作用,而当采用浓度1∶1进行试验时,表现出暴露时间为24、48、72 h的AI<0,联合作用结果表现为拮抗作用,而暴露时间为96 h时AI>0,联合作用结果则为协同作用,即随着暴露时间的增加,对二氯苯和镉的联合毒性作用从拮抗作用转变为毒性剧增的协同作用. 相似文献
85.
86.
M. Frei M.A. Razzak M.M. Hossain M. Oehme S. Dewan K. Becker 《Agriculture, ecosystems & environment》2007,120(2-4):391-398
Lowland rice fields constitute a semi aquatic environment, which is potentially suitable for fish production. Little is known about the effect of fish on greenhouse gas emissions from integrated rice–fish systems. An experiment was carried out at the Bangladesh Agricultural University to assess the effect of the stocking of fish on methane emissions from rice fields. Common carp, Cyprinus carpio L., and Nile Tilapia, Oreochromis niloticus (L.) were stocked in a mixed culture and subjected to three different input regimes: (1) urea fertilization according to the recommendation of the Bangladesh Rice Research Institute (BRRI), (2) supplementary feeding at 2 × maintenance level and (3) an elevated feeding schedule where 4 × maintenance level was fed initially and 2 × maintenance level towards the end of the growth period. Rice only with urea fertilization according to BRRI-recommendation was included as the control. The presence of fish increased methane emissions in all three rice–fish treatments. Average emission over the cropping season was 34, 37, and 32 mg m−2 h−1 in the rice–fish treatments, respectively, and 20 mg m−2 h−1 in rice only. Apart from an increase in methane emission, a significant drop (p < 0.05) in floodwater pH and dissolved oxygen concentration was observed in the rice–fish plots. Both parameters were the lowest in the treatment where a higher feeding rate was provided. Due to the fish activity, floodwater in the rice–fish treatments was more turbid, as reflected in higher particulate inorganic matter (PIOM). An elevated level of dissolved methane was observed in the floodwater of the feed supplemented rice–fish plots. Methane emissions showed negative correlation with morning and afternoon pH of the floodwater (r = −0.46; r = −0.56, p < 0.001) and morning and afternoon dissolved oxygen level (r = −0.53; r = −0.46, p < 0.001). Positive correlations were recorded between morning and afternoon floodwater temperature (r = 0.49; r = 0.44, p < 0.001) and with air temperature (r = 0.54, p < 0.001). The results suggest that the stocking of fish has an increasing effect on methane emissions from rice fields. 相似文献
87.
亚硝酸盐氮对草鱼种耗氧率的影响及适应性研究 总被引:1,自引:0,他引:1
通过测定全血红蛋白和高铁血红蛋白及耗氧率,研究了草鱼种在NO-N作用下的生理变化和对NO-N的适应性,结果表明:ρ(NO-N)在O~4mg·L-1范围内可使草鱼种耗氧率增加,并于1mp·L-1和4mg·L-1处出现峰值和次峰值;经暴露处理的鱼种在恢复21d后,显示出对NO-N的适应性. 相似文献
88.
Daniel E. Canfield Michael J. Maceina Jerome V. Shireman 《Journal of the American Water Resources Association》1983,19(5):773-778
ABSTRACT Changes in water chemistry, water clarity, and planktonic chlorophyll a were measured as hydrilla (Hydrilla verticillata) abundance increased and then decreased in Lake Baldwin, Florida. Grass carp (Ctenopharyngodon idella) were used to eliminate submersed macrophytes. No major trends in lake pH, conductivity, or total nitrogen concentrations occurred in association with changes in hydrilla levels. Increased Secchi disc transparency and reductions in total alkalinity, calcium, magnesium, potassium, total phosphorus, and chlorophyll a concentrations occurred as hydrilla abundance increased. Large increases in the chemical parameters and a reduction in Secchi disc transparency occurred as hydrilla decreased and was eliminated from the lake by grass carp. The effects of hydrilla on lake water chemistry are related to the percentage of the lake's volume infested with hydrilla and macrophyte standing crop. 相似文献
89.
Leonard J. Kouba 《Journal of the American Water Resources Association》1982,18(6):937-940
ABSTRACT: Fishing is a popular form of recreation in the state of Illinois. Despite seemingly endless varieties of fishing opportunities, limited public access, distant location of lakes with respect to population centers, chemical contaminants in some waters, and the desire for species not naturally found in Illinois have engendered an alternate form of recreational land use, the daily fee fishing area. A fee area is any privately controlled body of water or waters where a fee is charged for fishing. Such operations must Low licensed by the state of Illinois. Fee areas are almost entirely comprised of existing man-made impoundments, particularly farm ponds. They are usually stocked on a put and take basis. The most common species utilized in Illinois are carp and channel catfish. Fee areas are concentrated in the southwestern part of the state and near major metropolitan centers. Even though the number of fee areas has declined during the past decade, the role of such operations remains important to the overall picture of fishing in Illinois. 相似文献
90.
Mark B. Bain 《Environmental management》1993,17(2):211-224
Introduced species have created environmental benefits and unanticipated disasters so a priori assessments of species introductions
are needed for environmental management. A checklist for assessing impacts of introduced species was developed from studies
of introduced species and recommendations for planning introductions. Sterile, triploid grass carp (Ctenopharyngodon idella) are just beginning to be used as a biocontrol agent for the management of aquatic vegetation in open waterways. Potential
impacts of grass carp in open systems were identified by reviewing grass carp biology relative to the impact assessment checklist.
The potential consequences of introduced grass carp were reviewed for one case study. The case study demonstrated that conclusions
about potential impacts and monitoring needs can be made despite incomplete information and uncertainty.
Indicators of environmental impact and vulnerability of host systems were grouped into six categories: population control,
hybridization, diseases and parasites, habitat alterations, biological effects, and management issues. Triploid grass carp
can significantly alter habitat and biological resources through the secondary effects of reductions in aquatic vegetation.
Potential impacts and significant uncertainties involve fish dispersions from plant control areas, inability to control vegetation
loss, loss of diverse plant communities and their dependent species, and conflicts with human use of the water resource. Adequate
knowledge existed to assess most potential consequences of releasing large numbers of triploid grass carp in Guntersville
Reservoir, Alabama. However, the assessment of potential impacts indicated that moderate, incremental stockings combined with
monitoring of vegetation and biological resources are necessary to control the effects of grass carp and achieve desirable,
intermediate plant densities.
Cooperators: Auburn University (Alabama Agricultural Experiment Station, Department of Fisheries and Allied Aquacultures,
Department of Zoology and Wildlife Sciences), US Fish and Wildlife Service, Alabama Game and Fish Division, and the Wildlife
Management Institute. 相似文献