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排序方式: 共有180条查询结果,搜索用时 15 毫秒
41.
Kim M. Parsons 《Molecular ecology resources》2001,1(4):341-344
Noninvasive samples have proved useful in genotyping studies of free‐ranging mammals. However, potential genotyping errors associated with such samples dictate the need for validation studies. This pilot study demonstrates the use of dolphin faeces in multilocus microsatellite genotyping studies. An empirical approach to calculating the rate of genotyping error was applied to data from matched pairs of blood or tissue and faecal samples from both captive and wild bottlenose dolphins. Microsatellite genotypes were assigned to dolphin faecal extracts with greater than 95% confidence by using a multiple tube approach, and at least two independent replicate genotypings. 相似文献
42.
T. K. Rowles L. S. Schwacke R. S. Wells J. T. Saliki L. Hansen A. Hohn F. Townsend R. A. Sayre A. J. Hall 《Marine Mammal Science》2011,27(1):1-19
Cetacean morbilliviruses (CeMV) are viruses that can cause mass mortalities among various odontocete species. In this study levels of “herd” immunity in cetaceans from the U.S. coast are described from the distribution and prevalence of antibodies against morbilliviruses. Neutralizing antibody titers against dolphin morbillivirus (DMV), porpoise morbillivirus (PMV), phocine distemper (PDV), and canine distemper viruses (CDV) were measured. Positive samples had higher titers against the CeMV than against the other morbilliviruses tested, indicating that although PDV or CDV can be used to investigate exposure their use may result in a higher false negative rate. The results suggest that morbillivirus did not persist in coastal populations of bottlenose dolphins (Tursiops truncatus) after the major outbreaks that occurred in the 1980s and 1990s. Bottlenose dolphins from Beaufort, North Carolina; St. Joseph Bay, Florida; and Cape May, New Jersey had anti‐DMV seroprevalences ranging from between 15% and 33% but those from Charleston, South Carolina and Sarasota Bay, Florida, sampled in recent years were largely negative. These latter groups are therefore now vulnerable to infection and could experience high mortality if exposed to CeMV. Sero‐surveys of this kind are therefore vital for assessing the risk of new and recurring viral outbreaks in coastal cetaceans. 相似文献
43.
测定了斯氏钝绥螨Amblyseius swirskii(Athias—Henriot)在14、17、20、23、26、29、32、35℃和RH=85%的条件下,以截形叶螨为猎物各螨态的发育历期,分析发育速率与温度的关系。结果表明,14℃不适宜斯氏钝绥螨的生长发育,存活率仅17.5%;在17~35℃之间其生长发育正常,存活率均100%,各螨态的发育历期与温度均呈负相关关系,发育历期随着温度的升高明显缩短,未成熟期总发育历期从21.36d缩至3.97d。采用线性日度模型拟合温度与发育速率的关系表明,该模型能较好地描述其发育速率在适宜温度范围内随温度升高而加快的现象。斯氏钝绥螨不同发育阶段的发育起点温度和有效积温不同,未成熟期的发育起点温度和有效积温分别为11.92℃和94.69日·度。 相似文献
44.
Paul B. Conn Antoinette M. Gorgone Amelia R. Jugovich Barbie L. Byrd Larry J. Hansen 《The Journal of wildlife management》2011,75(3):569-579
We investigated the potential for using mark–recapture models to estimate abundance of bottlenose dolphin populations in open systems (e.g., bays, estuaries). A major challenge in these systems is that immigration and emigration occur during sampling, thus violating one of the most basic assumptions of mark–recapture models. We assumed that dolphins using our study site were composed of both residents (those that used the study area almost exclusively during our study), and transients (those that passed through our study area but did not remain long), and examined several mark–recapture estimators for their ability to accurately and precisely estimate the abundance of residents and the superpopulation (i.e., residents + transients). Using simulated data, we found that a novel approach accounting for transients resulted in estimators with less bias, smaller absolute relative error, and confidence interval coverage closer to nominal than other approaches, but this novel approach required intensive sampling and that the “correct” transient pattern be specified. In contrast, classical mark–recapture estimators for closed populations often overestimated the number of residents and underestimated the superpopulation. Using photo-identification records, a model-averaged estimate of the superpopulation of bottlenose dolphins in and around Choctawhatchee Bay, Florida was 232 (SE = 13) animals. We estimated resident abundance at 179 (SE = 8), which was lower than the number of unique animals we encountered (188). Our results appear promising for developing monitoring programs for bottlenose dolphins and other taxa in open systems. Our estimators should prove useful to wildlife managers who wish to base conservation decisions on estimates of the number of animals that reside primarily in their study or management area. © 2011 The Wildlife Society. 相似文献
45.
46.
三个黄颡鱼群体遗传多样性及亲缘关系的微卫星标记分析 总被引:1,自引:0,他引:1
利用微卫星标记技术对3个黄颡鱼群体(W S、TE和QF)的遗传多样性及亲缘关系进行研究。通过筛选的30个引物对3个黄颡鱼群体基因组DNA的扩增,获得了19个有效引物,其中有6个微卫星位点具有多态性,并计算出了3个黄颡鱼群体间的遗传相似系数和遗传距离,TE和QF群体间的遗传相似系数最大(0.8736),遗传距离最小(0.1790);W S和QF群体间的遗传相似系数最小(0.7284),遗传距离最大(0.2768)。同时运用聚类分析(UPGMA)的方法建立了3个黄颡鱼群体的系统发生树。 相似文献
47.
48.
IMPROVING MANAGEMENT OF OVERLAPPING BOTTLENOSE DOLPHIN ECOTYPES THROUGH SPATIAL ANALYSIS AND GENETICS 总被引:3,自引:0,他引:3
Leigh G. Torres Patricia E. Rosel Caterina D'Agrosa Andrew J. Read 《Marine Mammal Science》2003,19(3):502-514
In the Northwest Atlantic the distribution of coastal bottlenose dolphins ( Tursiops truncatus ) overlaps with that of the offshore ecotype. We hypothesized that the distribution of the two ecotypes could be delineated by depth and/or distance from shore, facilitating their identification during surveys. We obtained 304 skin biopsy samples and identified each as either coastal or offshore using analysis of mitochondrial DNA. We then interpreted the spatial distribution of coastal and offshore forms using spatial analysis. Using a Classification and Regression Tree (CART) analysis, we found a statistically significant break in ecotype distribution at 34 km from shore. In waters beyond 34 km from shore and deeper than 34 m, all bottlenose dolphins were of the offshore ecotype. Within 7.5 km of shore, all 65 samples were of the coastal ecotype. Between these two areas only nine samples were collected, so the genetic composition of bottlenose dolphins in this area remains poorly known. To enhance our understanding of the spatial distribution of the two ecotypes, future research should obtain more biopsy samples in this zone. Nevertheless, our results indicate that a conservative abundance estimate for the coastal ecotype could be generated from surveys of bottlenose dolphins within 7.5 km of shore. 相似文献
49.
ACOUSTIC IDENTIFICATION OF NINE DELPHINID SPECIES IN THE EASTERN TROPICAL PACIFIC OCEAN 总被引:1,自引:1,他引:0
Acoustic methods may improve the ability to identify cetacean species during shipboard surveys. Whistles were recorded from nine odontocete species in the eastern tropical Pacific to determine how reliably these vocalizations can be classified to species based on simple spectrographic measurements. Twelve variables were measured from each whistle ( n = 908). Parametric multivariate discriminant function analysis (DFA) correctly classified 41.1% of whistles to species. Non-parametric classification and regression tree (CART) analysis resulted in 51.4% correct classification. Striped dolphin whistles were most difficult to classify. Whistles of bottlenose dolphins, false killer whales, and pilot whales were most distinctive. Correct classification scores may be improved by adding prior probabilities that reflect species distribution to classification models, by measuring alternative whistle variables, using alternative classification techniques, and by localizing vocalizing dolphins when collecting data for classification models. 相似文献
50.
为了解植保无人机低空低容量喷雾对枣园主要害虫的防治效果,在植保无人机喷施农药后,调查了对截形叶螨、枣瘿蚊的防治效果,结果发现:在供试飞行条件下,药后5d25%环氧虫啶(用药量为300 g/hm2)、70%吡虫啉(用药量为150g/hm2)对枣瘿蚊的防治效果最高,分别为87.73%和89.74%,两处理之间无显著差异,均与22%噻虫?高氯氟(用药量为375 g/hm2)处理有显著性差异;药后13 d 30%乙唑螨腈(用药量为262.5 g/hm2)和45%螺虫?乙螨唑(用药量为105g/hm2)对不同方位枣树截形叶螨的防治效果在90%以上,平均防治效果分别为98.64%和93.95%,两处理之间无显著差异,与1.8%阿维菌素+20%双甲脒(用药量为345 g/hm2+525 g/hm2)有显著性差异;各处理雾滴覆盖密度之间均无显著性差异.因此,在生产中用植保无人机喷施25%环氧虫啶、70%吡虫啉、30%乙唑螨腈、45%螺虫?乙螨唑对枣园枣瘿蚊和截形叶螨能起到良好的防控效果. 相似文献