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方陵生 《海洋世界》2004,(12):27-29
在人类眼中看来。大白鲨是大海中最可怕的食肉动物。但是在鲨鱼眼中。对它们自己能否称得上海中霸主也许别有一番“见解”。  相似文献   
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The paper reviews the recent advances in studying grouper nutrition requirement for the development of cost-effective and environmentally friendly artificial diets. It consists of seven parts: protein and amino acid, lipid and essential fatty acid, carbohydrate, vitamin, mineral, alternative protein source, broodstock and larval nutrition. The review provides some basic information for further investigation of nutrient requirements of groupers.  相似文献   
3.
A new large-bodied theropod dinosaur,Datanglong guangxiensis gen.et sp.nov.,was recovered from the Lower Cretaceous Xinlong Formation of the Datang Basin,Guangxi.It is unique in several features including:posteriormost dorsal vertebra with teardrop-shaped pneumatic foramen confined by enlarged pcdl,acpl and the centrum; posteriormost dorsal with well-developed,horizontal prpl; posteriormost dorsal with a parapophysis projecting more laterally than the diapophysis; brevis fossa shallow with short,ridge-like medial blade; and iliac pubic peduncle with posteroventrally expanded margin.Cladistic analysis supports the idea that this new taxon Datanglong guangxiensis is a primitive member of the Carcharodontosauria in possessing two unambiguous synapomorphies:large external pneumatic foramina and internal spaces present in the lateral surface of ilium,and a peg-and-socket ischiac articulation with the ilium.The presence of the new taxon from Guangxi further confirms that Carcharodontosauria were cosmopolitan large-bodied predators during the Early–mid Cretaceous.  相似文献   
4.
《地图》2011,(3):12-12
迄今为止组装的最大鲨鱼颌骨化石,将于2011年6月12日在德克萨斯州达拉斯市的遗产拍卖行拍卖。这个史前地球上出现的体型最大食肉动物——巨齿鲨的颌骨,预计将被拍到70万美元或者更高。  相似文献   
5.
海星的世界     
猫猫 《海洋世界》2011,(9):46-46
你会想到平时一动不动的海星竟是一种贪婪的食肉动物吗?海星的主要捕食对象是一些行动较迟缓的海洋动物,如贝类、海胆、螃蟹和海葵等.一个海星一天能吃掉十几只扇贝,食量真是大得惊人.海星的消化能力很强,它能将胃从嘴里吐出来,直接选择食物,将自己要吃的部分卷住,然后连同胃一起缩进肚子里.尽管海星是一种凶残的捕食者,但它对自己的后...  相似文献   
6.
Vertical distribution of soil nematode communities under conventional tillage (CT),no-tillage (NT) and fallow field (FF) treatments in the Lower Reaches of the Liaohe River was investigated at six soil depths (0-5 cm,5-15 cm,15-30 cm,30-50 cm,50-75 cm and 75-100 cm). The results show that total nematode abundance gradually decreases with depth,and the highest number of total nematodes is observed at 0-5 cm depth under NT and FF treatments. The number of fungivores and plant parasites is significantly higher...  相似文献   
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