管狀蠕蟲又名管蠕蟲、管棲蠕蟲，是一種大型動物，身長能達到1~2米，直徑約數厘米。它們上端是一片紅色的肉頭，下端是一根直直的白色管子(zi)，管狀蠕(ru)蟲(chong)因此得(de)名(ming)，這也讓它們(men)看起來很(hen)像白莖(jing)紅花(hua)的巨型花(hua)朵(duo)。管狀蠕(ru)蟲(chong)很(hen)有可能(neng)是最長(chang)壽的動物——科學家估計(ji)有些個體可能(neng)已經活(huo)到了250歲。
管(guan)狀蠕(ru)蟲(chong)(chong)的(de)(de)(de)底部緊(jin)緊(jin)地(di)粘在海底底層巖石上(shang)，紅色肉(rou)頭部分可以活動。紅色的(de)(de)(de)肉(rou)頭有許多片狀觸手(shou)沿著(zhu)(zhu)一條中軸線緊(jin)密堆積起來，觸手(shou)上(shang)生(sheng)長著(zhu)(zhu)更小的(de)(de)(de)羽狀絨毛(mao)，看(kan)上(shang)去(qu)像(xiang)一根美麗的(de)(de)(de)羽毛(mao)。平時(shi)蠕(ru)蟲(chong)(chong)的(de)(de)(de)“羽毛(mao)”喜歡伸出(chu)管(guan)外，在海水里盡量舒展，但是(shi)(shi)當螃蟹或是(shi)(shi)科考(kao)的(de)(de)(de)機械手(shou)不小心(xin)觸碰了(le)它(ta)們的(de)(de)(de)時(shi)候，就會整個兒縮進白(bai)色硬管(guan)，躲著(zhu)(zhu)不出(chu)來了(le)。管(guan)狀蠕(ru)蟲(chong)(chong)有性別，有心(xin)臟(zang)，但沒有嘴和消(xiao)化系統，在管(guan)狀蠕(ru)蟲(chong)(chong)的(de)(de)(de)體內(nei)聚集著(zhu)(zhu)數(shu)以億萬(wan)計的(de)(de)(de)共生(sheng)菌，正是(shi)(shi)在這些細菌的(de)(de)(de)“供養(yang)”下，管(guan)狀蠕(ru)蟲(chong)(chong)才得以生(sheng)存。
管狀蠕蟲體內的共生菌從熱液中獲取硫離子，又從海中獲得氧氣，合成管狀蠕蟲生存所必須的有機物。所以管(guan)(guan)(guan)狀(zhuang)蠕蟲(chong)必須生(sheng)活(huo)在能同時接(jie)(jie)觸到海水(shui)和熱(re)液(ye)的(de)(de)區(qu)域，它們將身體白色的(de)(de)管(guan)(guan)(guan)狀(zhuang)部分(fen)固定(ding)在熱(re)液(ye)附近(jin)以獲取(qu)硫化物(wu)，而將紅色的(de)(de)肉頭部分(fen)漂浮在海水(shui)中(zhong)，與海水(shui)充分(fen)接(jie)(jie)觸以獲取(qu)氧氣。這(zhe)(zhe)樣，管(guan)(guan)(guan)狀(zhuang)蠕蟲(chong)底部處于20℃左右的(de)(de)熱(re)液(ye)附近(jin)，上部卻接(jie)(jie)近(jin)2℃的(de)(de)海水(shui)中(zhong)，身體跨越(yue)十幾度(du)的(de)(de)溫度(du)梯度(du)，這(zhe)(zhe)在其他生(sheng)物(wu)中(zhong)是(shi)極為罕(han)見的(de)(de)。
生活在陽光完全(quan)照射不到(dao)的(de)(de)(de)深海的(de)(de)(de)管狀蠕蟲，居然有(you)著和(he)哺(bu)乳(ru)動物一樣鮮紅的(de)(de)(de)血(xue)液。蠕蟲的(de)(de)(de)血(xue)液中(zhong)充(chong)滿(man)飽和(he)鐵(tie)質血(xue)紅蛋白(bai)，這(zhe)也是它(ta)肉頭(tou)部分有(you)著美麗鮮紅色的(de)(de)(de)原因。
管狀蠕蟲生(sheng)活的(de)海底熱液(ye)區高溫高壓，還(huan)充(chong)滿著氫(qing)(qing)氣和硫(liu)(liu)化氫(qing)(qing)，對于任何(he)一種(zhong)(zhong)我們(men)熟(shu)悉的(de)生(sheng)物(wu)來說，只要(yao)攝入微量硫(liu)(liu)化物(wu)，就(jiu)會使血液(ye)中(zhong)的(de)一種(zhong)(zhong)酶失活，生(sheng)物(wu)就(jiu)會因為無(wu)法(fa)呼(hu)吸而立(li)刻死亡(wang)，因此(ci)硫(liu)(liu)化物(wu)對于生(sheng)物(wu)來講是劇毒(du)的(de)。但管棲蠕蟲的(de)血液(ye)中(zhong)有(you)一種(zhong)(zhong)特殊的(de)血紅蛋白(bai)，它們(men)能與硫(liu)(liu)化氫(qing)(qing)結(jie)合，然后將后者運往共生(sheng)菌(jun)聚集的(de)地方。既防止了有(you)毒(du)氣體與酶結(jie)合，又避免了中(zhong)毒(du)。
科(ke)學(xue)(xue)家(jia)(jia)日(ri)前在(zai)美國加利(li)福(fu)尼亞州(zhou)沿海(hai)(hai)岸發(fa)現(xian)(xian)(xian)了(le)(le)兩(liang)(liang)種新(xin)(xin)的(de)(de)原(yuan)始蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)，與人(ren)類之前發(fa)現(xian)(xian)(xian)的(de)(de)深海(hai)(hai)類蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)不同這(zhe)兩(liang)(liang)種蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)以(yi)鯨(jing)魚骨(gu)(gu)頭為(wei)(wei)食(shi)。科(ke)學(xue)(xue)家(jia)(jia)將(jiang)其(qi)稱為(wei)(wei)“食(shi)骨(gu)(gu)類”蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)，并且在(zai)生(sheng)(sheng)物(wu)(wu)分(fen)(fen)(fen)類中(zhong)(zhong)為(wei)(wei)它(ta)(ta)(ta)(ta)們設置了(le)(le)一(yi)個新(xin)(xin)屬，命(ming)名為(wei)(wei)Osedax，其(qi)拉丁語詞源的(de)(de)意思是(shi)“吞吃(chi)骨(gu)(gu)頭的(de)(de)”。科(ke)學(xue)(xue)家(jia)(jia)說(shuo)，這(zhe)種蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)并沒有(you)(you)“胃”，但(dan)它(ta)(ta)(ta)(ta)身(shen)上(shang)(shang)的(de)(de)寄生(sheng)(sheng)細(xi)菌(jun)卻能(neng)夠幫它(ta)(ta)(ta)(ta)從(cong)鯨(jing)魚骨(gu)(gu)中(zhong)(zhong)吸取營(ying)(ying)養(yang)，并把營(ying)(ying)養(yang)儲存到它(ta)(ta)(ta)(ta)的(de)(de)根狀(zhuang)器官中(zhong)(zhong)。 海(hai)(hai)洋(yang)學(xue)(xue)家(jia)(jia)格雷格·盧斯等人(ren)首(shou)先在(zai)加州(zhou)蒙(meng)特(te)里(li)灣280米深的(de)(de)海(hai)(hai)水中(zhong)(zhong)首(shou)先發(fa)現(xian)(xian)(xian)了(le)(le)一(yi)種雌性管狀(zhuang)蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)，這(zhe)類蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)如同人(ren)的(de)(de)食(shi)指大小。它(ta)(ta)(ta)(ta)當時正吸附(fu)在(zai)一(yi)具灰鯨(jing)的(de)(de)腐(fu)尸上(shang)(shang)。他們起初很吃(chi)驚，因為(wei)(wei)只能(neng)找(zhao)(zhao)到雌性蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)。“但(dan)隨后我(wo)們在(zai)它(ta)(ta)(ta)(ta)的(de)(de)體內找(zhao)(zhao)到了(le)(le)雄性蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)，雄性蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)剛進入成(cheng)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)期(qi)，已可(ke)以(yi)看到體內的(de)(de)精子。” 科(ke)學(xue)(xue)家(jia)(jia)說(shuo)，這(zhe)類蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)的(de)(de)生(sheng)(sheng)活方式(shi)表明(ming)，在(zai)缺(que)乏營(ying)(ying)養(yang)物(wu)(wu)質的(de)(de)海(hai)(hai)底(di)(di)(di)環境中(zhong)(zhong)，死去(qu)的(de)(de)鯨(jing)可(ke)以(yi)成(cheng)為(wei)(wei)巨大的(de)(de)能(neng)量來源，成(cheng)為(wei)(wei)深海(hai)(hai)生(sheng)(sheng)態系(xi)統中(zhong)(zhong)的(de)(de)重要環節。人(ren)類對(dui)鯨(jing)進行濫(lan)(lan)捕(bu)濫(lan)(lan)殺，可(ke)能(neng)會損(sun)害深海(hai)(hai)的(de)(de)生(sheng)(sheng)物(wu)(wu)多(duo)樣(yang)性。 最新(xin)(xin)一(yi)期(qi)美國《科(ke)學(xue)(xue)》雜(za)志上(shang)(shang)有(you)(you)報告說(shuo)，新(xin)(xin)型蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)是(shi)在(zai)太平洋(yang)底(di)(di)(di)部一(yi)副鯨(jing)的(de)(de)骨(gu)(gu)架上(shang)(shang)發(fa)現(xian)(xian)(xian)的(de)(de)，該區(qu)域水深約3200米。這(zhe)些(xie)蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)既沒有(you)(you)嘴(zui)，也沒有(you)(you)消(xiao)化器官，它(ta)(ta)(ta)(ta)們通過(guo)附(fu)肢(zhi)里(li)共生(sheng)(sheng)的(de)(de)細(xi)菌(jun)攝取營(ying)(ying)養(yang)。附(fu)肢(zhi)的(de)(de)形(xing)態像樹根，可(ke)用(yong)于在(zai)鯨(jing)骨(gu)(gu)髓(sui)里(li)“挖掘(jue)”，細(xi)菌(jun)將(jiang)骨(gu)(gu)中(zhong)(zhong)的(de)(de)脂肪轉化成(cheng)糖(tang)，蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)就(jiu)靠這(zhe)些(xie)糖(tang)生(sheng)(sheng)活。 人(ren)們曾經(jing)認為(wei)(wei)，深海(hai)(hai)海(hai)(hai)底(di)(di)(di)是(shi)生(sheng)(sheng)命(ming)的(de)(de)荒原(yuan)，因為(wei)(wei)那(nei)里(li)黑(hei)暗而且營(ying)(ying)養(yang)物(wu)(wu)質匱乏。但(dan)自1977年(nian)以(yi)來，在(zai)海(hai)(hai)底(di)(di)(di)噴(pen)出熱水和礦物(wu)(wu)質的(de)(de)熱液(ye)噴(pen)口附(fu)近(jin)，發(fa)現(xian)(xian)(xian)了(le)(le)多(duo)種蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)和細(xi)菌(jun)。有(you)(you)的(de)(de)蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)與細(xi)菌(jun)共生(sheng)(sheng)，靠細(xi)菌(jun)分(fen)(fen)(fen)解硫(liu)等無機物(wu)(wu)生(sheng)(sheng)活。DNA分(fen)(fen)(fen)析表明(ming)，新(xin)(xin)發(fa)現(xian)(xian)(xian)的(de)(de)靠鯨(jing)骨(gu)(gu)生(sheng)(sheng)活的(de)(de)蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)，與海(hai)(hai)底(di)(di)(di)熱液(ye)噴(pen)口的(de)(de)蠕(ru)(ru)(ru)(ru)(ru)(ru)(ru)(ru)蟲(chong)(chong)(chong)(chong)(chong)(chong)(chong)親緣關(guan)系(xi)很近(jin)。?
管狀蠕(ru)蟲是深海海底熱液(ye)區的代表性(xing)物(wu)種。
目前已探知的(de)海(hai)(hai)底熱液地區(qu)有(you)：Mohna海(hai)(hai)嶺(ling)、南大西洋海(hai)(hai)嶺(ling)、卡爾斯(si)伯格海(hai)(hai)嶺(ling)、巴布亞新幾內亞的(de)Ambitle島(dao)以及(ji)加拉帕(pa)戈斯(si)群島(dao)。
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