多年來,，鯊魚以其兇猛的血盆大口而出名,，但現(xiàn)在科學(xué)家發(fā)現(xiàn)鯊魚可怕的大嘴其實(shí)并不兇猛，甚至可以說是“懦弱無力”,。相比之下,，老虎和獅子的嘴就要厲害得多。相關(guān)論文發(fā)表在《生理學(xué)和生化動(dòng)物學(xué)》（Physiological and Biochemical Zoology）雜志,。
研究人員發(fā)現(xiàn)可怕的鯊魚能用其非常鋒利的牙齒撕咬獵物,，但按照大小來說，鯊魚的嘴不算厲害,。負(fù)責(zé)此項(xiàng)研究的美國(guó)佛羅里達(dá)州坦帕大學(xué)的丹尼爾·胡伯說：“從體重來說,，鯊魚嘴咬得并不厲害。”胡伯博士及其小組通過研究10種不同的鯊魚并測(cè)量其咬力之后得出這一結(jié)論,。
研究人員通過敲擊和電擊它們來刺激其嘴部肌肉,，從而測(cè)量它們的咬勁。他們發(fā)現(xiàn)鯊魚能制造很大的破壞,，因?yàn)槠溲例X如此鋒利且嘴巴又如此之大,。論文中寫道：“我們的分析表明，大型鯊魚沒有咬得太狠,，但它們漸漸進(jìn)化出了一個(gè)更大的頭部,。”研究表明，獅子和老虎的咬勁勝過了鯊魚,。不過,，鯊魚由于有較大的嘴，在水里占有優(yōu)勢(shì),。一條6米長(zhǎng)的大白鯊可以咬穿你的身體,，而許多動(dòng)物得使用鋸的動(dòng)作才能撕裂獵物,。胡伯博士表示，哺乳動(dòng)物已經(jīng)進(jìn)化出了更加有效的嘴部肌肉,。（生物谷Bioon.com）
生物谷推薦原始出處：
Physiological and Biochemical Zoology,，DOI: 10.1086/588177，Daniel R. Huber ,，Anthony Herrel
Is Extreme Bite Performance Associated with Extreme Morphologies in Sharks
Daniel R. Huber1,Julien M. Claes2 Jér?me Mallefet2 Anthony Herrel3,4
1Department of Biology, University of Tampa, 401 West Kennedy Boulevard, Box U, Tampa, Florida 33606; 2Marine Biology Lab (BMAR), Catholic University of Louvain, Batiment Kellner, niveau D-1, 3 place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium; 3Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, Massachusetts 02138; 4Department of Biology, University of Antwerp, Universiteitsplein 1, B-2610 Antwerpen, Belgium
Abstract
As top predators in many oceanic communities, sharks are known to eat large prey and are supposedly able to generate high bite forces. This notion has, however, largely gone untested due to the experimental intractability of these animals. For those species that have been investigated, it remains unclear whether their high bite forces are simply a consequence of their large body size or the result of diet-related adaptation. As aquatic poikilotherms, sharks can grow very large, making them ideal subjects with which to investigate the effects of body size on bite force. Relative bite-force capacity is often associated with changes in head shape because taller or wider heads can, for example, accommodate larger jaw muscles. Constraints on bite force in general may also be released by changes in tooth shape. For example, more pointed teeth may allow a predator to penetrate prey more effectively than blunt, pavementlike teeth. Our analyses show that large sharks do not bite hard for their body size, but they generally have larger heads. Head width is the best predictor of bite force across the species included in our study as indicated by a multiple regression model. Contrary to our predictions, sharks with relatively high bite forces for their body size also have relatively more pointed teeth at the front of the tooth row. Moreover, species including hard prey in their diet are characterized by high bite forces and narrow and pointed teeth at the jaw symphysis.
