基本介紹

電(dian)(dian)(dian)(dian)鰻是(shi)一(yi)種水生生物，它們(men)可(ke)以(yi)(yi)在(zai)水中(zhong)放(fang)電(dian)(dian)(dian)(dian)，放(fang)電(dian)(dian)(dian)(dian)是(shi)它們(men)保護自己和捕食的(de)有(you)效手段。電(dian)(dian)(dian)(dian)鰻可(ke)以(yi)(yi)釋(shi)放(fang)出(chu)的(de)電(dian)(dian)(dian)(dian)力(li)是(shi)比(bi)較(jiao)強的(de)，電(dian)(dian)(dian)(dian)壓甚至可(ke)以(yi)(yi)達到800V，因(yin)此許多人(ren)將(jiang)(jiang)它們(men)稱為(wei)“水中(zhong)的(de)高壓線”。電(dian)(dian)(dian)(dian)鰻是(shi)否可(ke)以(yi)(yi)將(jiang)(jiang)人(ren)類電(dian)(dian)(dian)(dian)死是(shi)不(bu)一(yi)定的(de)，有(you)些大電(dian)(dian)(dian)(dian)鰻可(ke)以(yi)(yi)將(jiang)(jiang)人(ren)電(dian)(dian)(dian)(dian)死，但(dan)有(you)些小(xiao)電(dian)(dian)(dian)(dian)鰻則不(bu)行(xing)，因(yin)為(wei)它們(men)放(fang)出(chu)的(de)電(dian)(dian)(dian)(dian)比(bi)較(jiao)弱。

電鰻具有比較(jiao)強的(de)(de)(de)放(fang)(fang)(fang)(fang)電能力，可以放(fang)(fang)(fang)(fang)電，跟(gen)它們(men)(men)的(de)(de)(de)身(shen)體(ti)構造有很大(da)的(de)(de)(de)關系(xi)。電鰻的(de)(de)(de)身(shen)體(ti)和器(qi)官(guan)構造跟(gen)同(tong)樣生活在水中的(de)(de)(de)魚類有很大(da)的(de)(de)(de)差(cha)異，它們(men)(men)的(de)(de)(de)重(zhong)要器(qi)官(guan)，比如(ru)下心臟(zang)、肝臟(zang)等，距它們(men)(men)頭部是非(fei)常(chang)近的(de)(de)(de)，幾乎可以說它們(men)(men)的(de)(de)(de)重(zhong)要器(qi)官(guan)都在它們(men)(men)身(shen)體(ti)的(de)(de)(de)前部位置(zhi)。它們(men)(men)身(shen)體(ti)的(de)(de)(de)其余部分(fen)，則分(fen)布著許多肌肉和電細胞。這(zhe)(zhe)些電細胞是用(yong)來放(fang)(fang)(fang)(fang)電的(de)(de)(de)，在它們(men)(men)身(shen)體(ti)上大(da)概80%的(de)(de)(de)位置(zhi)上都有分(fen)布。這(zhe)(zhe)些電細胞很像是電池。電鰻若是想放(fang)(fang)(fang)(fang)電，會先通過神經系(xi)統(tong)來傳遞一個(ge)(ge)信號(hao)，當被這(zhe)(zhe)個(ge)(ge)信號(hao)刺(ci)激(ji)之后，電細胞就會迅(xun)速讓離子通過細胞膜，從而放(fang)(fang)(fang)(fang)電。

生長與分布

生活環境

電鰻的生存環(huan)(huan)境大多為渾濁、緩流的水域，這種地方給它帶來了兩個特(te)點(dian)：第一是(shi)眼睛基本(ben)沒什(shen)么(me)用(yong)了，很早就退化(hua)了，必(bi)須依(yi)靠(kao)微弱的電流探知(zhi)周圍環(huan)(huan)境，所(suo)以電鰻的電路其實(shi)是(shi)長時開(kai)放的；第二就是(shi)這么(me)臟(zang)的水里肯(ken)定也長不出什(shen)么(me)好看的顏(yan)色(se)，所(suo)以電鰻的體色(se)十分一般，上體灰黑，下腹桔黃，是(shi)很通俗的色(se)彩。

分布范圍

電鰻是生長于熱(re)帶(dai)及溫帶(dai)地區(qu)水(shui)域的純淡水(shui)魚類，分布在南美洲(zhou)的亞馬(ma)孫河、圭(gui)亞那河、奧里諾科河流域。

形態及特征

電鰻行(xing)動(dong)遲(chi)緩，棲(qi)息于(yu)(yu)緩流的淡水(shui)(shui)水(shui)(shui)體中，并(bing)不時(shi)上(shang)浮水(shui)(shui)面，吞入空(kong)氣，進行(xing)呼吸。體長可達2.5公尺，體重(zhong)可達20千克，整體圓(yuan)柱形(xing)，體表光滑無鱗，背(bei)部黑(hei)色(se)，腹部橙黃色(se)。背(bei)鰭、尾鰭退(tui)化，但占體全長近4/5的尾，其下緣(yuan)有一長形(xing)臀鰭，依靠(kao)臀鰭的撥動(dong)而游動(dong)。尾部具(ju)發電器，來源(yuan)于(yu)(yu)肌(ji)肉組織(zhi)，并(bing)受脊(ji)神(shen)經支(zhi)配。體有兩對形(xing)狀為長梭形(xing)的發電器，位于(yu)(yu)尾部脊(ji)髓(sui)兩側。

特別要(yao)說明(ming)的(de)是(shi)，電(dian)鰻尾部兩側(ce)的(de)肌(ji)肉(rou)，是(shi)由有規則地排列著的(de)6000～10000枚肌(ji)肉(rou)薄片(pian)組成(cheng)，薄片(pian)之(zhi)間有結締組織相隔，并有許多神(shen)(shen)經直(zhi)通(tong)中樞(shu)神(shen)(shen)經系統。每枚肌(ji)肉(rou)薄片(pian)像一個小電(dian)池，只能產(chan)生150毫(hao)伏(fu)的(de)電(dian)壓，但近萬(wan)個“小電(dian)池”串(chuan)聯(lian)起來，就可以產(chan)生很高的(de)電(dian)壓。

生活習性

電鰻常在(zai)夜間捕(bu)食(shi)，食(shi)物(wu)中(zhong)有小魚(yu)、蟹、蝦(xia)、甲殼動(dong)物(wu)和水生(sheng)昆蟲，也食(shi)動(dong)物(wu)腐敗尸體(ti)(ti)，更有部(bu)分個體(ti)(ti)的食(shi)物(wu)中(zhong)發現有高(gao)等植(zhi)物(wu)碎屑。

電(dian)鰻(man)捕(bu)食(shi)(shi)的時(shi)候，首先(xian)悄悄地(di)游(you)近魚群，然后(hou)可連續放出(chu)電(dian)流(liu)，受到電(dian)擊的魚馬(ma)上暈厥過(guo)去，身體僵直(zhi)，于是，電(dian)鰻(man)乘(cheng)機吞食(shi)(shi)它們。電(dian)鰻(man)放電(dian)，有時(shi)也不一(yi)定(ding)是為了捕(bu)食(shi)(shi)，也可能是一(yi)種生理(li)需要(yao)。被電(dian)鰻(man)電(dian)死的魚，往往超過(guo)它們食(shi)(shi)用所需要(yao)的量(liang)，這給漁業生產帶來危(wei)害。

南美洲土著居民利用電鰻連續不斷地放電后，需要經過一段時間休息和補充豐富的食物后，才能恢復原有的放電強度的特點，先將一群牛馬趕下河去，使電鰻被激怒而不斷放電，待電鰻放完電精疲力盡時，直接捕捉。

飼養方法

人工飼養中(zhong)電鰻對水體更沒什么要(yao)(yao)求(qiu)，微(wei)酸至中(zhong)性水質(zhi)，15℃以(yi)(yi)上的水溫——這(zhe)個溫度甚至冬天家里(li)有暖(nuan)氣(qi)的話(hua)連(lian)加熱棒(bang)都不用放——然(ran)后過濾系統盡(jin)量提供緩動(dong)的水流即可。電鰻還會直接呼(hu)吸空氣(qi)，連(lian)水體容氧的問題(ti)都不必(bi)擔心(xin)。它們的肛門雖然(ran)就在(zai)胸腹部下方，消化(hua)道(dao)極短，但還是挺能吃的。并且由于它沒有牙齒，不能牢固咬住獵物，所以(yi)(yi)每電擊(ji)必(bi)至對方于死地，投喂時務必(bi)小心(xin)，不要(yao)(yao)自己把手放進(jin)水里(li)。

電鰻有天敵嗎

電(dian)(dian)(dian)鰻(man)除了(le)(le)人類幾乎沒(mei)有任何天敵。電(dian)(dian)(dian)鰻(man)能產生足以將人擊(ji)昏的(de)電(dian)(dian)(dian)流，是放電(dian)(dian)(dian)能力(li)最強的(de)淡水魚類，輸出(chu)的(de)電(dian)(dian)(dian)壓可達300～800伏。據網友(you)拍攝的(de)一(yi)段視頻顯示，一(yi)條(tiao)鱷(e)魚觀察著旁邊的(de)電(dian)(dian)(dian)鰻(man)，猛(meng)地將其一(yi)把咬住，不料被(bei)電(dian)(dian)(dian)流擊(ji)得(de)渾身顫抖(dou)。不一(yi)會(hui)兒便被(bei)電(dian)(dian)(dian)死了(le)(le)。

電鰻為什么會放電

電(dian)(dian)(dian)(dian)(dian)鰻的(de)(de)(de)(de)(de)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)能力來自于它特(te)化的(de)(de)(de)(de)(de)肌(ji)肉組織(zhi)所構成的(de)(de)(de)(de)(de)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)體(ti)。肌(ji)肉組織(zhi)幾乎都(dou)能放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)，占(zhan)其身長的(de)(de)(de)(de)(de)80%以上，有(you)數以千計的(de)(de)(de)(de)(de)放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)體(ti)。電(dian)(dian)(dian)(dian)(dian)鰻的(de)(de)(de)(de)(de)頭部是(shi)(shi)負極(ji)，尾部是(shi)(shi)正極(ji)，每個放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)體(ti)約可制造0.15伏特(te)的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓，而當數千個放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)體(ti)一(yi)起全(quan)力放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)時的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓便高達600～800伏特(te)，但這種高電(dian)(dian)(dian)(dian)(dian)壓只能維持非(fei)常短暫的(de)(de)(de)(de)(de)時間，而且放(fang)(fang)(fang)電(dian)(dian)(dian)(dian)(dian)能力會(hui)隨著疲勞或(huo)衰老的(de)(de)(de)(de)(de)程(cheng)度而減退。電(dian)(dian)(dian)(dian)(dian)鰻能自由控制要放(fang)(fang)(fang)出(chu)什么程(cheng)度的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)力，一(yi)般認為電(dian)(dian)(dian)(dian)(dian)鰻放(fang)(fang)(fang)出(chu)低電(dian)(dian)(dian)(dian)(dian)力的(de)(de)(de)(de)(de)目的(de)(de)(de)(de)(de)是(shi)(shi)在(zai)警(jing)告、試(shi)探或(huo)偵(zhen)測。

放電原理

電(dian)(dian)鰻體(ti)內有(you)一些(xie)細(xi)胞就像小型的(de)(de)(de)(de)(de)疊層(ceng)(ceng)電(dian)(dian)池(chi)，當(dang)它(ta)被神經信號(hao)所激勵時，能陡然使離子(zi)流(liu)通過它(ta)的(de)(de)(de)(de)(de)細(xi)胞膜(mo)。電(dian)(dian)鰻體(ti)內從頭到尾都(dou)有(you)這樣(yang)的(de)(de)(de)(de)(de)細(xi)胞，就像許多(duo)疊在(zai)(zai)一起的(de)(de)(de)(de)(de)疊層(ceng)(ceng)電(dian)(dian)池(chi)。當(dang)產(chan)(chan)(chan)生電(dian)(dian)流(liu)時，所有(you)這些(xie)電(dian)(dian)池(chi)（每個電(dian)(dian)池(chi)電(dian)(dian)壓(ya)約0.15伏）都(dou)串(chuan)聯(lian)起來(lai)，這樣(yang)在(zai)(zai)電(dian)(dian)鰻的(de)(de)(de)(de)(de)頭和尾之間(jian)就產(chan)(chan)(chan)生了很高的(de)(de)(de)(de)(de)電(dian)(dian)壓(ya)。許多(duo)這樣(yang)的(de)(de)(de)(de)(de)電(dian)(dian)池(chi)組又(you)并(bing)聯(lian)起來(lai)，這樣(yang)就能在(zai)(zai)體(ti)外產(chan)(chan)(chan)生足夠大的(de)(de)(de)(de)(de)電(dian)(dian)流(liu)。用(yong)這些(xie)電(dian)(dian)流(liu)足以將它(ta)的(de)(de)(de)(de)(de)獵(lie)物或天敵擊暈或擊斃。淡水(shui)里的(de)(de)(de)(de)(de)電(dian)(dian)魚(yu)需(xu)要更多(duo)的(de)(de)(de)(de)(de)電(dian)(dian)池(chi)串(chuan)聯(lian)在(zai)(zai)一起，因為淡水(shui)的(de)(de)(de)(de)(de)電(dian)(dian)阻較大，產(chan)(chan)(chan)生同(tong)樣(yang)的(de)(de)(de)(de)(de)電(dian)(dian)流(liu)需(xu)要更高的(de)(de)(de)(de)(de)的(de)(de)(de)(de)(de)電(dian)(dian)壓(ya)。

放電能力

電(dian)(dian)(dian)(dian)(dian)(dian)鰻(man)能隨意放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)，自己掌握(wo)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)和強(qiang)度(du)，發電(dian)(dian)(dian)(dian)(dian)(dian)器最主要的(de)(de)(de)(de)樞紐是(shi)器官的(de)(de)(de)(de)神經部分。電(dian)(dian)(dian)(dian)(dian)(dian)鰻(man)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)的(de)(de)(de)(de)平均電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)為350多(duo)伏，但也有過(guo)650伏的(de)(de)(de)(de)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)記錄。美洲電(dian)(dian)(dian)(dian)(dian)(dian)鰻(man)的(de)(de)(de)(de)最大電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)竟達800多(duo)伏，這么強(qiang)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)足以(yi)擊(ji)死一頭牛。電(dian)(dian)(dian)(dian)(dian)(dian)鰻(man)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)產(chan)生的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)是(shi)極微弱(ruo)的(de)(de)(de)(de)，一般(ban)不到(dao)1安培(pei)；有時(shi)觀察到(dao)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)為500伏，電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)為2安培(pei)，即(ji)功率為1000瓦的(de)(de)(de)(de)短(duan)時(shi)放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)。雖然(ran)發出的(de)(de)(de)(de)是(shi)直流(liu)電(dian)(dian)(dian)(dian)(dian)(dian)，但放(fang)(fang)電(dian)(dian)(dian)(dian)(dian)(dian)頻率每秒可(ke)達300個脈沖。

放電的損傷力

放電(dian)的(de)損傷力取決(jue)于鰻魚的(de)大(da)小和機體(ti)的(de)狀況。當電(dian)鰻長(chang)不到(dao)1米時，電(dian)壓(ya)隨(sui)著電(dian)鰻的(de)成長(chang)而增加。當長(chang)到(dao)1米后(hou)，只增加電(dian)流的(de)強度。電(dian)鰻每秒(miao)鐘能放電(dian)50次，但連續放電(dian)后(hou)，電(dian)流逐(zhu)漸減弱，10～15秒(miao)鐘后(hou)完全消(xiao)失(shi)，休息一會后(hou)又能重新恢復放電(dian)能力。在水中3～6米范圍內，常有人觸(chu)及電(dian)鰻放出(chu)的(de)電(dian)而被擊昏(hun)，甚至(zhi)因(yin)此(ci)跌入水中而被淹死。

依靠電來感知周圍環境

電(dian)鰻(man)尾部發出的(de)(de)(de)(de)電(dian)流(liu)(liu)，流(liu)(liu)向頭部的(de)(de)(de)(de)感(gan)受(shou)器(qi)，因此在它身體周(zhou)圍形成一個弱電(dian)場。電(dian)鰻(man)中(zhong)樞神經系統中(zhong)有(you)專門的(de)(de)(de)(de)細胞來監(jian)視(shi)電(dian)感(gan)受(shou)器(qi)的(de)(de)(de)(de)活動，并(bing)能根據監(jian)視(shi)分析的(de)(de)(de)(de)結(jie)果(guo)(guo)指揮電(dian)鰻(man)的(de)(de)(de)(de)行為，決定采取捕(bu)食行為或避讓行為或其它行為。有(you)人曾經做過這(zhe)(zhe)樣一個實驗：在水池中(zhong)放(fang)置兩根垂直的(de)(de)(de)(de)導線，放(fang)入電(dian)鰻(man)，并(bing)將(jiang)水池放(fang)在黑(hei)暗(an)的(de)(de)(de)(de)環(huan)境里，結(jie)果(guo)(guo)發現電(dian)鰻(man)總在導線中(zhong)間穿(chuan)梭(suo)，一點兒也不會碰導線；當導線通電(dian)后，電(dian)鰻(man)迅速往后跑。這(zhe)(zhe)說明電(dian)鰻(man)是靠“電(dian)感(gan)”來判斷周(zhou)圍環(huan)境的(de)(de)(de)(de)。

電鰻自身不被電的原因

電(dian)(dian)(dian)(dian)鰻(man)的(de)(de)(de)放(fang)(fang)電(dian)(dian)(dian)(dian)器官在(zai)身體(ti)(ti)的(de)(de)(de)兩側(ce)，而且它大(da)部分的(de)(de)(de)身體(ti)(ti)或重要的(de)(de)(de)器官都(dou)由(you)絕(jue)緣性很高的(de)(de)(de)構造包(bao)住，在(zai)水(shui)中就像是(shi)一個大(da)電(dian)(dian)(dian)(dian)池(chi)。電(dian)(dian)(dian)(dian)流由(you)電(dian)(dian)(dian)(dian)阻(zu)最小的(de)(de)(de)通路經過，所以在(zai)水(shui)中放(fang)(fang)電(dian)(dian)(dian)(dian)時(shi)，電(dian)(dian)(dian)(dian)流會(hui)經由(you)水(shui)（電(dian)(dian)(dian)(dian)阻(zu)比(bi)電(dian)(dian)(dian)(dian)鰻(man)身體(ti)(ti)小）傳遞(di)，電(dian)(dian)(dian)(dian)鰻(man)并(bing)不(bu)會(hui)電(dian)(dian)(dian)(dian)到(dao)自(zi)已。但如果電(dian)(dian)(dian)(dian)鰻(man)被抓到(dao)空氣中，因(yin)空氣的(de)(de)(de)電(dian)(dian)(dian)(dian)阻(zu)比(bi)它身體(ti)(ti)的(de)(de)(de)電(dian)(dian)(dian)(dian)阻(zu)更大(da)，放(fang)(fang)電(dian)(dian)(dian)(dian)的(de)(de)(de)話(hua)就會(hui)電(dian)(dian)(dian)(dian)到(dao)自(zi)已了。另外，如果電(dian)(dian)(dian)(dian)鰻(man)受傷(shang)使兩側(ce)的(de)(de)(de)絕(jue)緣體(ti)(ti)同時(shi)破損(sun)的(de)(de)(de)話(hua)，放(fang)(fang)電(dian)(dian)(dian)(dian)時(shi)就會(hui)像兩條裸露的(de)(de)(de)電(dian)(dian)(dian)(dian)線(xian)一樣發生短路的(de)(de)(de)現象(xiang)。