據(jù)英國新科學(xué)家雜志報(bào)道，海豚沒有餐刀,，但是它們卻是捕獵屠殺獵物,，并將獵物制成美味食物的頂尖高手。近期,，澳大利亞研究人員觀測到一只雌性寬吻海豚上演了一系列精確的捕獵技巧——殺死獵物,，解剖內(nèi)臟，剔除骨骼,。
海豚的6步驟獵殺過程去除了墨魚體內(nèi)的墨汁和難以下咽的墨魚骨,。英國埃克塞特大學(xué)進(jìn)化生物學(xué)家湯姆·特里根扎(Tom Tregenza)說：“海豚的捕獵行為非常顯而易見,，并且非常有效,，它們懂得如何將獵物變成美味可口的食物。”
澳大利亞墨爾本市維多利亞博物館海洋生物學(xué)家朱利安·費(fèi)恩(Julian Finn)分別在2003年和2007年觀測到一只雌性海豚表演的水下捕獵活動,，據(jù)悉,，當(dāng)時他正在研究墨魚的交配行為，在澳大利亞南部海域生活著大量墨魚,。
海豚先將墨魚從海底的海藻叢中驅(qū)趕到海底一個開放區(qū)域,，接下來它捕捉到墨魚，用嘴叼著猛烈地撞擊海底,，為了去除墨魚體內(nèi)的墨汁,，它用嘴叼著墨魚尸體反復(fù)地在水中搖擺，直到海水沖刷干凈墨魚體內(nèi)的墨汁,。之后,，海豚將墨魚的尸體在海底沙子中碾磨，以分解它的骨骼,。特里根扎說：“在這一過程中，你有興趣的話可以聽到墨魚被碾磨分解時發(fā)出的噪音,。在我們拍攝的這段視頻中,，墨魚骨骼最終像香皂塊一樣從身體上脫離出來。”最后,，海豚才開始享受這頓美味大餐,。
雖然費(fèi)恩僅拍攝到一只海豚的這種奇特捕食行為，但海豚的這種技巧并非是個別現(xiàn)象,。特里根扎說：“我猜測如果我們在海底投入更多的時間和精力,，將能看到其他的海豚類似的捕食技巧,。”
在觀測中研究人員意識到一個新的問題——第一只懂得該捕獵方法的海豚是如何形成該技巧的？之前,，研究人員曾展示雌性海豚教授自己的孩子在捕食魚的時候如何用嘴叼著海綿,，像揮動著一只盾牌。近期的一項(xiàng)研究顯示,，雌性小海豚要比雄性小海豚更渴望掌握一些生存技巧,。
海豚這種奇特的捕獵技巧應(yīng)當(dāng)是海豚群體的普遍現(xiàn)象，特里根扎稱,，很可能是海豚發(fā)明了這種捕獵,、制作食物的方法，它們很可能是從母親或者姐姐那里學(xué)習(xí)這種技能,。（生物谷Bioon.com）
生物谷推薦原始出處：
PLoS ONE 4(1): e4217. doi:10.1371/journal.pone.0004217
Preparing the Perfect Cuttlefish Meal: Complex Prey Handling by Dolphins
Julian Finn1,2*, Tom Tregenza3, Mark Norman1
1 Sciences, Museum Victoria, Melbourne, Victoria, Australia, 2 Department of Zoology, La Trobe University, Victoria, Australia, 3 Centre for Ecology and Conservation, School of Biosciences, University of Exeter, Cornwall Campus, Tremough, Penryn, United Kingdom
Abstract
Dolphins are well known for their complex social and foraging behaviours. Direct underwater observations of wild dolphin feeding behaviour however are rare. At mass spawning aggregations of giant cuttlefish (Sepia apama) in the Upper Spencer Gulf in South Australia, a wild female Indo-Pacific bottlenose dolphin (Tursiops aduncus) was observed and recorded repeatedly catching, killing and preparing cuttlefish for consumption using a specific and ordered sequence of behaviours. Cuttlefish were herded to a sand substrate, pinned to the seafloor, killed by downward thrust, raised mid-water and beaten by the dolphin with its snout until the ink was released and drained. The deceased cuttlefish was then returned to the seafloor, inverted and forced along the sand substrate in order to strip the thin dorsal layer of skin off the mantle, thus releasing the buoyant calcareous cuttlebone. This stepped behavioural sequence significantly improves prey quality through 1) removal of the ink (with constituent melanin and tyrosine), and 2) the calcareous cuttlebone. Observations of foraging dolphin pods from above-water at this site (including the surfacing of intact clean cuttlebones) suggest that some or all of this prey handling sequence may be used widely by dolphins in the region. Aspects of the unique mass spawning aggregations of giant cuttlefish in this region of South Australia may have contributed to the evolution of this behaviour through both high abundances of spawning and weakened post-spawning cuttlefish in a small area (>10,000 animals on several kilometres of narrow rocky reef), as well as potential long-term and regular visitation by dolphin pods to this site.
