幼年时期的大白鲨是笨拙的猎手
文章来源:未知 文章作者:meng 发布时间:2010-12-03 01:56 字体: [ ]  进入论坛
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The jaws2 of adolescent great white sharks may be too weak to capture and kill large marine3 mammals, according to a new study published in the Journal of Biomechanics(生物力学) by an international team of scientists. The researchers also found that, unlike mammals, sharks can maintain high bite forces no matter how widely their jaws are open, thanks to a unique jaw1 muscle arrangement that has helped them to be among the most successful predators4(捕食者) of all time.

The study is the first of its kind to use sophisticated three-dimensional computer models and advanced engineering techniques to examine how different sharks hunt and kill prey5.

Detailed6 computer simulations examined the feeding behaviour of two threatened shark species: the harmless grey nurse – or sand tiger - and the notorious(声名狼藉的) great white.

Digital models revealed that the jaws of grey nurse sharks are spring-loaded for a rapid strike on small, fast-moving fish, while those of great whites are better suited for a powerful bite on prey ranging in size from small fish to large marine mammals.

"We were surprised that although the teeth and jaws of our sub-adult great white shark looked the part and the muscles were there to drive them, the jaws themselves just couldn't handle the stress associated with big bites on big prey," says study co-author Dr Stephen Wroe, who heads the Computational Biomechanics Research Group in the UNSW School of Biological, Earth and Environmental Sciences.

The reason for this appears to be that until great whites reach a length of about 3 metres or more their jaws haven't developed enough stiff mineralised cartilage(软骨) to resist the forces involved.

The 2.5 metre great white shark used for the study was caught by the NSW Bather Protection Program. "It is hard to believe, but at this size great whites are basically just awkward(尴尬的,笨拙的) teenagers that can't hunt large prey very effectively," says UNSW doctoral student Toni Ferrara, the lead author of the article. "It seems paradoxical that the iconic jaws of great white sharks - made infamous7 by the classic Steven Spielberg movie Jaws - are actually rather vulnerable when these sharks are young. Great white sharks are not born super-predators, they take years to become formidable(强大的,可怕的) hunters."

Co-author Dr Vic Peddemors, of the NSW Cronulla Fisheries Research Centre of Excellence8, says: "This study may also explain why many of the shark attacks off NSW are aborted9 after a single exploratory bite, as the great whites involved are usually juveniles10 that might sustain jaw injury if they persevered11 with the attack."



点击收听单词发音收听单词发音  

1 jaw 5xgy9     
n.颚,颌,说教,流言蜚语;v.喋喋不休,教训
参考例句:
  • He delivered a right hook to his opponent's jaw.他给了对方下巴一记右钩拳。
  • A strong square jaw is a sign of firm character.强健的方下巴是刚毅性格的标志。
2 jaws cq9zZq     
n.口部;嘴
参考例句:
  • The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
  • The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。
3 marine 77Izo     
adj.海的;海生的;航海的;海事的;n.水兵
参考例句:
  • Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
  • When the war broke out,he volunteered for the Marine Corps.战争爆发时,他自愿参加了海军陆战队。
4 predators 48b965855934a5395e409c1112d94f63     
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面)
参考例句:
  • birds and their earthbound predators 鸟和地面上捕食它们的动物
  • The eyes of predators are highly sensitive to the slightest movement. 捕食性动物的眼睛能感觉到最细小的动静。 来自《简明英汉词典》
5 prey g1czH     
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨
参考例句:
  • Stronger animals prey on weaker ones.弱肉强食。
  • The lion was hunting for its prey.狮子在寻找猎物。
6 detailed xuNzms     
adj.详细的,详尽的,极注意细节的,完全的
参考例句:
  • He had made a detailed study of the terrain.他对地形作了缜密的研究。
  • A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。
7 infamous K7ax3     
adj.声名狼藉的,臭名昭著的,邪恶的
参考例句:
  • He was infamous for his anti-feminist attitudes.他因反对女性主义而声名狼藉。
  • I was shocked by her infamous behaviour.她的无耻行径令我震惊。
8 excellence ZnhxM     
n.优秀,杰出,(pl.)优点,美德
参考例句:
  • His art has reached a high degree of excellence.他的艺术已达到炉火纯青的地步。
  • My performance is far below excellence.我的表演离优秀还差得远呢。
9 aborted dfb7069bfc6e0064a6c667626eca07b4     
adj.流产的,失败的v.(使)流产( abort的过去式和过去分词 );(使)(某事物)中止;(因故障等而)(使)(飞机、宇宙飞船、导弹等)中断飞行;(使)(飞行任务等)中途失败
参考例句:
  • The rocket flight had to be aborted because of difficulties with computer. 因电脑出故障,这次火箭飞行只好中辍。 来自《简明英汉词典》
  • They aborted the space flight finally. 他们最后中止了这次宇航飞行。 来自《简明英汉词典》
10 juveniles 257c9101f917ec8748aa5fc520c6a9e3     
n.青少年( juvenile的名词复数 );扮演少年角色的演员;未成年人
参考例句:
  • Do you think that punishment for violent crimes should be the same for juveniles and adults? 你对暴力犯罪的惩罚对于青少年和成人应一样吗? 来自生活英语口语25天快训
  • Juveniles Should we not exactly in need of such strength and conviction? 少年的我们难道不正是需要这种力量和信念吗? 来自互联网
11 persevered b3246393c709e55e93de64dc63360d37     
v.坚忍,坚持( persevere的过去式和过去分词 )
参考例句:
  • She persevered with her violin lessons. 她孜孜不倦地学习小提琴。
  • Hard as the conditions were, he persevered in his studies. 虽然条件艰苦,但他仍坚持学习。 来自辞典例句
TAG标签: species mammals sharks jaws
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