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911.
Dispersal of young fish through wind‐driven currents has a growing research focus in large freshwater lakes; however, the influence of behaviour on such dispersal has not been tested. Fish may orient to different environmental cues and use swimming behaviours to navigate towards or retain their position within important habitats. To examine the ability of larval and juvenile fishes of the Laurentian Great Lakes to perceive and orient to nearshore or offshore habitats, we carried out a series of behavioural trials in a flume in which fish choose between different combinations of nearshore and offshore water, and well water. Water and a natural assemblage of larval and juvenile nearshore fish (Dominant species: white sucker, Catostomus commersonii, and spottail shiners, Notropis hudonius) used in the experiment were collected from northern Lake Michigan near Beaver Island. Results of our study suggest that young fish are capable of distinguishing and responding to different water sources, indicating a potential to orient within their environment, such as through the use of olfactory cues. We did not see a difference in fish response to changing concentrations of water cues, possibly suggesting that the threshold for fish response occurs at lower concentrations than were tested in our experiments. This preliminary study into orientation of Great Lakes fishes demonstrates the capacity of these fish to orient to cues in water sources and indicates the need to consider active movement in future studies of larval dispersal and habitat choice in the large freshwater lakes.  相似文献   
912.
将天麻水提取液经过NKA–9大孔吸附树脂与制备型液相色谱联用方法分离,获得6个主要活性成分,通过质谱仪和核磁共振仪鉴定其结构分别为天麻素、对羟基苯甲醇、巴利森苷E、巴利森苷B、巴利森苷C、巴利森苷A;采用HPLC方法测定不同产地初加工样品中这些活性成分的含量,杀青后干燥与不杀青直接干燥的天麻活性成分含量间的差异有统计学意义,不杀青样中对羟基苯甲醇含量显著高于杀青样中的含量,其他活性成分含量则显著低于杀青样中的含量;蒸、煮2种杀青方法中6个活性成分及总含量间的差异均无统计学意义,煮法、蒸法、不杀青处理的天麻活性成分总含量依次降低;切片与整块干燥处理样中,各活性成分及总含量间的差异均无统计学意义,但切片干燥的天麻活性成分总含量高于整块干燥的含量;不同干燥温度处理样中,各活性成分及总含量间的差异均无统计学意义,70、60、50℃温度干燥的天麻活性成分总含量依次降低。新鲜天麻煮法杀青,切片,在70℃干燥下活性成分总含量最高,为较好的初加工方法。  相似文献   
913.
The article compared behavioral characteristics of dogs (Canis lupis familiaris) labeled as hearing and/or vision impaired by their owners with cohort dogs labeled as having normal hearing and vision (NHV) by their owners. The Canine Behavioral Assessment and Research Questionnaire, developed by Hsu and Serpell (2003), was used to survey owners. Four hundred sixty-one dog owners completed the online survey, with 183 of these being owners of hearing and/or vision impaired (HVI) dogs. Data analysis revealed that HVI dogs were reported by owners to show less aggression, less excitement, and were less likely to engage in behaviors, such as chasing of rabbits and rolling in feces than their normally hearing/seeing (NHV) cohorts. HVI dogs, however, were reported to be more likely to chew inappropriate objects, consume feces, bark excessively, and engage in greater licking behavior. When owners were surveyed about the type of training method used, owners of HVI dogs were found to be more likely to use hand signs, physical prompts, or combination of these training methods. Owners of NHV dogs reported being more likely than owners of HVI dogs to use gestures or report no formal training with their dogs. The data provide evidence that HVI dogs are as trainable as NHV dogs, can make excellent pets, and show behavior that is well within the parameters of NHV dog behavior. Still, because of their sensory limitations, specialized training methods and adaptations should be implemented with these dogs. This may limit HVI dogs to owners who are motivated, understand the sensory deficits, and are willing to engage in the modified training.  相似文献   
914.
桃蛀螟是苹果树重要害虫,果实被害后失去食用价值。采用四臂嗅觉仪研究成熟果、青果、花及各自正己烷提取液对桃蛀螟产卵行为的影响。结果表明:桃蛀螟产卵行为因苹果不同部位而有显著的差异性,24 h后桃蛀螟在青果上的产卵量显著高于其他部位及其正己烷提取液的产卵量。  相似文献   
915.
玉米秸碎料无胶模压成型蠕变特性初探   总被引:1,自引:0,他引:1  
研究了玉米秸碎料无胶模压成型过程中温度、压力和碎料含水率等工艺因素对其蠕变特性的影响,试验结果显示:3个因素均对玉米秸碎料模压成型蠕变特性有显著影响;模压温度120℃、压力5.6 MPa和碎料含水率12%时,玉米秸碎料的压缩蠕变量最大.  相似文献   
916.
以脱氢枞胺为原料合成了四种氨基酸类两性表面活性剂,它们分别是N-脱氢枞基氨基 内、丙酸钠、乙基磺酸钠、(2-羟基O丙基磺酸钠。对产物结构进行了鉴定,测定了它们的表面物理性质及抗菌性能,并对结构与性质之间关系进行了探索。  相似文献   
917.
笼养川金丝猴哺乳行为的观察   总被引:5,自引:0,他引:5  
采用全事件抽样法对笼养的5只成年雌猴和3只幼猴进行了连续13个月计183d的行为观察。结果表明,川金丝猴的初次哺乳是在胎儿娩出后3.1h以后;根据哺乳的行为特征,哺乳期可分为初期、中期、晚期和后期;哺乳分为3种类型,即生理性哺乳、过渡性哺乳和心理性哺乳;哺乳时同笼母猴对幼猴有阿姨行为。  相似文献   
918.
银合欢异木虱形态及生物学研究   总被引:2,自引:0,他引:2  
银合欢异木虱(Heteropsylla Cubana Crauford)是危害银合欢的重要害虫。成虫和若虫刺吸嫩梢幼叶汁液,并排泄蜜露,导致发生煤烟病。被害嫩梢幼叶萎缩干枯,严重影响生长和产量。每年10月至翌年4月为严重为害期。雌虫产卵量为32—330粒。在海南省儋州地区每年发生15—16代,完成一世代需16—21天。在室外用自然变温法测定其发育起点温度,全世代平均为7.58℃,其中卵为9.05℃,若虫为9.56℃,成虫为4.04℃。完成一世代的有效积温为373.93日度。用空间分布型指数法对调查数据进行测定,田间卵的空间分布为聚集分布型。  相似文献   
919.
ABSTRACT:   The tail beat and activity behavior of four captive Japanese flounder Paralichthys olivaceus , were monitored with acceleration data-loggers while the fish swam in an aquarium. Depth, swimming speeds and two-axis acceleration data were collected continuously for approximately 20 h per fish. Simultaneously, the swimming behaviors of the fish were filmed at different angles. Using the specific characteristic of the acceleration profiles, in tandem with other types of data (e.g. speed and depth), four behavioral patterns could be distinguished: (i) 'active' swimming; (ii) burying patterns; (iii) 'inactive' gliding; and (iv) lying on the bottom. Tail beat frequency ranged from 1.65 ± 0.47 to 2.04 ± 0.25 Hz (mean ± SD; n  = 4). Using the relationship between tail beat frequency and swimming speed, the 'preferred' swimming speed of the fish was estimated to be between 0.6 and 1.2 body lengths (BL)/s. Additionally, fish rarely swam faster than 1.2 BL/s. This study shows that the acceleration data-loggers represent a useful and reliable system for accurately recording the tail beat of free-ranging fish and estimating flatfish behavior.  相似文献   
920.
ABSTRACT:   An apparatus to measure the locomotor activity of aquatic benthic organisms at variable low light levels was developed and the diurnal behavioral pattern of the abalone Haliotis discus discus was measured at various low light intensities. During the experiment, abalone were exposed to 12 h light–dark cycles of complete darkness, 0 µmol/m2/s throughout the 12 h dark cycle and, during periods I (days 1–8) and III (days 19–26), the 12 h light cycles were set at 10 µmol/m2/s. During period II (days 10–17), abalone were exposed to a light level during the 12 h light cycles of 1 × 10−5, 1 × 10−6, 1 × 10−7 or 1 × 10−8 µmol/m2/s and the changes in locomotor activity assessed. At daytime levels of 1 × 10−5 µmol/m2/s, typical behavioral patterns were observed of high locomotory activity during the night-time cycle. However, at lower light intensities, the distinction between day and night activity patterns became less clear and, at intensities lower than 1 × 10−7 µmol/m2/s, the difference between activity during the light and dark cycles became negligible. Based on this, we conclude that the threshold of light level perception in relation to locomotor activity is approximately 1 × 10−7 µmol/m2/s. The significance of these results in relation to the entrainment of behavior in abalone is discussed.  相似文献   
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