在古希臘神話中,，九頭蛇讓戰(zhàn)神赫拉克勒斯總有種如鯁在喉的感覺,，而在海洋世界里，雙頭海蛇也讓食肉動物有了同樣的感覺,。
瑞典克里斯蒂安斯塔德大學(xué)的生態(tài)學(xué)家約翰·埃爾姆博格(Johan Elmberg)和丹麥哥本哈根動物保護(hù)學(xué)院的生物學(xué)家阿恩·拉斯穆森(Arne Rasmussen)在刊登于《海洋生態(tài)學(xué)》(Marine Ecology)的最新研究報告中寫道,，像厚尾海蛇(Hydrophis pachycercos)這樣的海蛇種類不斷進(jìn)化，使得鯊魚等海洋食肉動物無法分辨這種大蛇是來還是去,。
埃爾姆博格說,，一次，拉斯穆森去印度尼西亞進(jìn)行科考研究,，“他看到一只分泌毒液的海蛇先是一頭鉆進(jìn)狹窄的裂縫,，接著，他吃驚地發(fā)現(xiàn),，這條海蛇后面竟然還長著個頭,，看上去它可以在裂縫中非常快速靈活地轉(zhuǎn)身,。”過了一會兒,，拉斯穆森才意識到，后面的“頭”其實(shí)是尾巴,。
埃爾姆博格介紹說,，這是一種黃唇毒蛇，晝伏夜出,，在淺水活動,，“還在暗礁裂縫中穿梭尋找魚類”，“尾巴慢慢地來回扭動,，而頭部也幾乎以相同方式移動,。”后來，經(jīng)過對保存在歐洲三個不同博物館的98個3英尺長(約合1米)熱帶蛇種標(biāo)本的細(xì)致研究,，兩位研究人員得出了這樣的結(jié)論：所有黃唇海蛇都有兩個頭,。
埃爾姆博格說：“我認(rèn)為這種雙頭模式和來回?fù)u擺移動可能會嚇走潛在的食肉動物，讓它們誤以為尾巴是有毒的頭,。”此后,，埃爾姆博格和拉斯穆森又在所羅門群島所在的南太平洋水域和別的地方發(fā)現(xiàn),，像厚尾海蛇這樣的海蛇種類都具有相似的特征。盡管埃爾姆博格和拉斯穆森并未親眼見到厚尾海蛇像頭一樣扭動它們的尾巴,，但二人都認(rèn)為它們肯定會這樣做,。（生物谷Bioon.com）
生物谷推薦原始出處：
Marine Ecology Date: July 2009
'Head for my tail': a new hypothesis to explain how venomous sea snakes avoid becoming prey
Arne Redsted Rasmussen 1 & Johan Elmberg 2
1 The Royal Danish Academy of Fine Arts, School of Conservation, Copenhagen, Denmark
2 Aquatic biology and chemistry, Kristianstad University, Kristianstad, Sweden
Sea snakes are widespread and conspicuous inhabitants of shallow waters in the Indian and Pacific Oceans. They are agile top predators and possess extremely potent venom, but they are still susceptible to predation by large fish, e.g. sharks, and other vertebrates. We describe how crevice-probing and temporarily non-vigilant Yellow-lipped Sea Kraits Laticauda colubrina twist the tail around their length axis so that the tail tip's lateral aspect corresponds to the dorsal view of the head. In doing so, coloration and pattern in combination with tail movement and posture make the tail appear very similar to the (non-visible and foraging) head. We examined 98 Laticauda spp. sea snakes in three major museum collections and reviewed the literature to assess the generality and implications of our field observations. This leads us to hypothesize that a combination of: (i) head and tail being similarly coloured and patterned, and (ii) the tail being motioned to resemble the head, is a hitherto overlooked mimetic and 'prophylactic' anti-predator adaptation in the L. colubrina complex, and possibly in other species of sea snake. We propose this is a concerted behavioural–morphological adaptation, and we briefly speculate about its possible fitness trade-offs as well as its origin. Explicit and testable predictions derived from the hypothesis are presented.
