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埃及的木乃伊 ,被考古学家挖出研究的不下五万具。1851年 ,法国考古学家奥丘斯·马里埃在开罗近郊的地下 ,发掘出了一座巨大的陵墓。陵墓是用精工磨制的黑红相间的花岗岩砌成的。在数千斤重的石棺中 ,人们惊奇地看到一具牛的木乃伊卧在其中。大约5000年前 ,埃及人把努比亚野生猫和山猫杂交 ,得到了新变种。由于新种猫特别能吃老鼠 ,所以受到埃及人的保护和崇拜 ,在神殿里铸造了各种神态的青铜猫。猫死了 ,还要制成木乃伊 ,涂以香料 ,隆重下葬。1860年 ,在埃及的别尼哈桑发现了古埃及的猫的墓地 ,这里竟埋葬着18万只猫的木乃伊… 相似文献
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概述了鳄类动物的繁殖生物学特性。对在其它爬行动物中不多见,而在鳄类中普遍存在的亲体关怀行为和孵化温度决定后代性别的现象进行了阐述。并从生态学和进化论角度,对这些现象进行了讨论。 相似文献
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本文简介了分支系统学意义上的鳄型动物(CrocodylomorphaWalker.1970)的组成。首次应用分支系统学方法讨论了重庆西蜀鳄的系统发有关系。本文的结论否定了西蜀鳄和西贝鳄类系统关系相近的论点,并认为前者比后者要原始得多,它是Mesoeucrocodylia中最原始的代表之一。 相似文献
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本文报道了1997~1998年湾鳄(Crocodylusporosus)的人工孵化工作,并通过对比试验确定了鳄卵孵化的最适温度、湿度以及最佳的覆盖巢材和鳄卵在孵化盘中的正确摆放方位。获得受精卵总孵化率为86-8%。1 材料方法试验用卵取自深圳市野生动物园湾鳄产下的卵。将所有收集到的未破损的受精卵分成2组,一组为湾鳄在人工设置的产卵间内自然营巢产的卵,按母鳄产卵时自然摆放的方位放入盛卵盘内作为正放组;另一组为没有营巢环境而产于水泥地或草地上的滚动过的卵作为对照组。2 结 果2-1 1997年有3条… 相似文献
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AdamBritton 《人与生物圈》2012,(5)
“看,它冲出菖蒲和芦苇丛,腹部滚圆,高高地甩着那满是褶皱的尾巴,漂浮在湖面上。血盆大口处,水流如瀑;宽阔鼻孔中,雾气滚滚。大地在它脚下颤抖,发出雷鸣般的声音。” 相似文献
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Merchant M Williams S Trosclair PL Elsey RM Mills K 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,148(4):921-925
Temperature probes were inserted into the stomachs of juvenile American alligators (Alligator mississippiensis) maintained outdoors at ambient fluctuating temperatures. Internal body temperatures (Tb) were measured every 15 min for two days, and then the alligators were injected with bacterial lipopolysaccharide (LPS), pyrogen-free saline, or left untreated. Alligators injected intraperitoneally with LPS exhibited maximum Tbs 2.6 ± 1.1 °C and 3.5 ± 1.2 °C higher than untreated control animals on days one and two after treatment, respectively. Tbs for these animals fell to within control ranges by day three postinjection. Similarly, mean preferred body temperatures (MPBTs) were significantly higher for LPS-injected alligators on days one (4.2 ± 1.8 °C) and two (3.5 ± 1.6 °C) after treatment. Intraperitoneal injection of heat-killed Aeromonas hydrophila, a gram-negative bacterium known to infect crocodilians, resulted in a fever while injection of Staphylococcus aureus (gram positive) did not elicit a febrile response. Injection of LPS in alligators maintained indoors in a constant temperature environment resulted in no increase in internal Tb. These results indicate that alligators did not exhibit a febrile response in the absence of a thermal gradient, and suggest that febrile responses observed are probably behavioral in nature. 相似文献
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Lee G. Miles Stacey L. Lance Sally R. Isberg Chris Moran Travis C. Glenn 《Conservation Genetics》2009,10(4):935-954
Microsatellite DNA loci have emerged as the dominant genetic tool for addressing questions associated with genetic diversity
in many wildlife species, including crocodilians. Despite their usefulness, their isolation and development can be costly,
as well as labour intensive, limiting their wider use in many crocodilian species. In this study, we investigate the cross-species
amplification success of 82 existing microsatellites previously isolated for the saltwater crocodile (Crocodylus porosus) in 18 non-target crocodilian species; Alligator sinensis, Caiman crocodylus, Caiman latirostris, Caiman yacare, Melanosuchus niger, Paleosuchus palpebrosus, Crocodylus acutus, Mecistops cataphractus, Crocodylus intermedius, Crocodylus johnstoni, Crocodylus mindorensis, Crocodylus moreletii, Crocodylus niloticus, Crocodylus novaeguineae, Crocodylus palustis, Crocodylus rhombifer, Crocodylus siamensis, and Osteolaemus tetraspis. Our results show a high level of microsatellites cross-amplification making available polymorphic markers for a range of
crocodilian species previously lacking informative genetic markers. 相似文献
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Mark Merchant Clint Kinney Paige Sanders 《Comparative biochemistry and physiology. Part D, Genomics & proteomics》2009,4(4):300-304
Blood was collected from three juvenile alligators (Alligator mississippiensis) before, and again 24 h after, injection with bacterial lipopolysaccharide (LPS). The leukocytes were collected from both samples, and the proteins were extracted. Each group of proteins was labeled with a different fluorescent dye and the differences in protein expression were analyzed by two dimensional differential in-gel expressions (2D-DIGE). The proteins which appeared to be increased or decreased by treatment with LPS were selected and analyzed by MALDI-TOF to determine mass and LC–MS/MS to acquire the partial protein sequences. The peptide sequences were compared to the NCBI protein sequence database to determine homology with other sequences from other species. Several proteins of interest appeared to be increased upon LPS stimulation. Proteins with homology to human transgelin-2, fish glucose-6-phosphate dehydrogenase, amphibian α-enolase, alligator lactate dehydrogenase, fish ubiquitin-activating enzyme, and fungal β-tubulin were also increased after LPS injection. Proteins with homology to fish vimentin 4, murine heterogeneous nuclear ribonucleoprotein A3, and avian calreticulin were found to be decreased in response to LPS. In addition, five proteins, four of which were up-regulated (827, 560, 512, and 650%) and one that exhibited repressed expression (307%), did not show homology to any protein in the database, and thus may represent newly discovered proteins. We are using this biochemical approach to isolate and characterize alligator proteins with potential relevant immune function. 相似文献
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Merchant M Britton A 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2006,143(4):488-493
We employed a spectroscopic assay, based on the hemolysis of sheep red blood cells (SRBCs), to assess the innate immune function of saltwater and freshwater crocodiles in vitro. Incubation of serum from freshwater and saltwater crocodiles with SRBCs resulted in concentration-dependent increases in SRBC hemolysis. The hemolytic activity occurred rapidly, with detectable activity within 2 min and maximum activity at 20 min. These activities, in both crocodilian species, were heat sensitive, unaffected by 20 mM methylamine, and completely inhibited by low concentrations of EDTA, suggesting that the alternative serum complement cascade is responsible for the observed effects. The hemolytic activities of the sera were inhibited by other chelators of divalent metal ions, such as phosphate and citrate. The inhibition of SRBC hemolysis by EDTA could be completely restored by the addition of 10 mM Ca2+ or Mg2+, but not Ba2+, Cu2+ or Fe2+, indicating specificity for these metal ions. The serum complement activities of both crocodilians were temperature-dependent, with peak activities occurring at 25-30 degrees C and reduced activities below 25 degrees C and above 35 degrees C. 相似文献
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This study investigated growth, condition and development of American eels Anguilla rostrata that were introduced into a European river to estimate their competitive potential in a non‐native habitat. Results demonstrate that A. rostrata develops normally in European waters and successfully competes with the native European eel Anguilla anguilla. In addition, A. rostrata appears to be more susceptible to the Asian swimbladder nematode Anguillicola crassus than A. anguilla and could support the further propagation of this parasite. Detected differences in fat content and gonad mass between Anguilla species are assumed to reflect species‐specific adaptations to spawning migration distances. This study indicates that A. rostrata is a potential competitor for the native fauna in European fresh waters and suggests strict import regulations to prevent additional pressure on A. anguilla and a potential further deterioration of its stock situation. 相似文献
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Coprolites can preserve a wide range of biogenic components. Of all the coprolites known from the fossil record, hitherto only two are known to preserve vertebrate tooth impressions (i.e., those of chondrichthyans). Here, a coprolite, from a thick lag deposit that includes a mixture of late Cretaceous, early Paleocene, and Plio-Pleistocene taxa at Clapp Creek in Kingstree, Williamsburg County, South Carolina, USA, preserves bite marks most consistent with having been made by a gar, Lepisosteus sp. (Lepisosteidae, Actinopterygii). This is the first-known coprolite to preserve actinopterygian tooth/bite marks. Aborted coprophagy seems unlikely; an accidental or serendipitous strike more likely describes the origin of the score marks over the surface of the coprolite. This coprolite also preserves small paired striations interpreted as evidence of coprophagy by an unknown organism. 相似文献
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Monika H. Ståhls Audrey L. Mayer Päivi M. Tikka Pekka E. Kauppi 《Journal of Industrial Ecology》2010,14(4):576-585
International trade transfers social and environmental impacts across national borders. The consumption of forest products often takes place far away from industrial production sites, and mills procure raw material from remote forests. Finland produces about 10% of forest products that are traded internationally, with the majority of its exports destined for other European countries. Here we report and analyze data that demonstrate that international leakage, in relative terms, increased faster than the production of commodities. The international consumption of products made in Finland increased, and an increase in wood imports from Russia provided the raw material for most of the incremental production. The international consumption‐production system translated the increasing global demand for Finnish products into increased harvests in Russia, until the Russian customs duties started to increase in 2007. We argue that national and regional policies for the promotion of sustainable consumption and production must be analyzed and assessed from an international, holistic perspective. 相似文献
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