刺(ci)胞動(dong)(dong)(dong)物(wu)門(men)(men)(Cnidaria)又稱(cheng)刺(ci)細胞動(dong)(dong)(dong)物(wu)門(men)(men),過去稱(cheng)為(wei)(wei)(wei)(wei)(wei)腔(qiang)腸動(dong)(dong)(dong)物(wu)門(men)(men)(Coelenterata),因為(wei)(wei)(wei)(wei)(wei)它(ta)的含義適用(yong)于(yu)(yu)(yu)刺(ci)胞動(dong)(dong)(dong)物(wu)及櫛水(shui)(shui)(shui)母(mu)(mu)動(dong)(dong)(dong)物(wu),所以(yi)現(xian)(xian)多已廢棄不用(yong)。刺(ci)胞動(dong)(dong)(dong)物(wu)體(ti)呈(cheng)輻(fu)射或兩輻(fu)射對稱(cheng),僅具二胚(pei)層,是(shi)最原(yuan)始(shi)的后(hou)(hou)生(sheng)(sheng)動(dong)(dong)(dong)物(wu)。體(ti)壁(bi)由(you)外(wai)(wai)胚(pei)層、內胚(pei)層和(he)中膠(jiao)層組成。內胚(pei)層圍成身體(ti)的整(zheng)個內腔(qiang)稱(cheng)消(xiao)化循環(huan)腔(qiang),腔(qiang)腸一端為(wei)(wei)(wei)(wei)(wei)口,他端閉(bi)塞,無(wu)肛門(men)(men)。體(ti)壁(bi)中有(you)(you)(you)(you)刺(ci)細胞。腔(qiang)腸動(dong)(dong)(dong)物(wu)的骨(gu)骼主(zhu)要(yao)為(wei)(wei)(wei)(wei)(wei)外(wai)(wai)骨(gu)骼,具有(you)(you)(you)(you)支持和(he)保護功能。多由(you)幾丁(ding)質(zhi)、角(jiao)質(zhi)和(he)石灰質(zhi)構成。在很多珊(shan)瑚(hu)(hu)蟲(chong)中具有(you)(you)(you)(you)骨(gu)針或骨(gu)軸,它(ta)們(men)存在于(yu)(yu)(yu)中膠(jiao)層,或突出(chu)于(yu)(yu)(yu)體(ti)表(biao)面。有(you)(you)(you)(you)無(wu)性和(he)有(you)(you)(you)(you)性兩種(zhong)(zhong)生(sheng)(sheng)殖(zhi)(zhi)方(fang)式,并往往出(chu)現(xian)(xian)在同一種(zhong)(zhong)的生(sheng)(sheng)活(huo)(huo)史中,即水(shui)(shui)(shui)螅型世代用(yong)無(wu)性出(chu)芽生(sheng)(sheng)殖(zhi)(zhi)方(fang)式產生(sheng)(sheng)水(shui)(shui)(shui)母(mu)(mu)型世代,而水(shui)(shui)(shui)母(mu)(mu)型個體(ti)脫離母(mu)(mu)體(ti),長大成熟(shu)以(yi)后(hou)(hou),又以(yi)有(you)(you)(you)(you)性生(sheng)(sheng)殖(zhi)(zhi)方(fang)式產生(sheng)(sheng)水(shui)(shui)(shui)螅型個體(ti),兩個世代互相交(jiao)替完成整(zheng)個生(sheng)(sheng)活(huo)(huo)史。約1萬(wan)種(zhong)(zhong),可(ke)分為(wei)(wei)(wei)(wei)(wei):水(shui)(shui)(shui)螅蟲(chong)綱、缽水(shui)(shui)(shui)母(mu)(mu)綱和(he)珊(shan)瑚(hu)(hu)蟲(chong)綱3綱,一般認為(wei)(wei)(wei)(wei)(wei)水(shui)(shui)(shui)螅蟲(chong)綱是(shi)最原(yuan)始(shi)的。絕大部分海(hai)產,只(zhi)有(you)(you)(you)(you)少(shao)數種(zhong)(zhong)類(lei)產于(yu)(yu)(yu)淡(dan)水(shui)(shui)(shui),以(yi)熱帶(dai)和(he)亞熱帶(dai)海(hai)洋(yang)(yang)的淺(qian)水(shui)(shui)(shui)區最豐富。較小種(zhong)(zhong)類(lei)可(ke)作(zuo)魚類(lei)食餌(er),珊(shan)瑚(hu)(hu)骨(gu)骼(如(ru)紅(hong)珊(shan)瑚(hu)(hu))可(ke)作(zuo)工藝品,古珊(shan)瑚(hu)(hu)和(he)現(xian)(xian)代珊(shan)瑚(hu)(hu)可(ke)形成儲油層,海(hai)邊的珊(shan)瑚(hu)(hu)礁可(ke)作(zuo)天(tian)然海(hai)堤;海(hai)蜇鹽漬(zi)后(hou)(hou)成為(wei)(wei)(wei)(wei)(wei)食品,有(you)(you)(you)(you)些種(zhong)(zhong)類(lei)可(ke)作(zuo)藥用(yong);有(you)(you)(you)(you)些浮游水(shui)(shui)(shui)母(mu)(mu)類(lei)可(ke)作(zuo)為(wei)(wei)(wei)(wei)(wei)海(hai)流(liu)指示生(sheng)(sheng)物(wu);但是(shi),有(you)(you)(you)(you)些大型水(shui)(shui)(shui)母(mu)(mu)(如(ru)霞水(shui)(shui)(shui)母(mu)(mu)、根口水(shui)(shui)(shui)母(mu)(mu))在大量出(chu)現(xian)(xian)時(shi),會阻塞或破壞漁網,有(you)(you)(you)(you)的海(hai)葵(kui)混于(yu)(yu)(yu)漁獲物(wu)中,人(ren)食后(hou)(hou)中毒致死。刺(ci)胞動(dong)(dong)(dong)物(wu)除極少(shao)數種(zhong)(zhong)類(lei)為(wei)(wei)(wei)(wei)(wei)淡(dan)水(shui)(shui)(shui)生(sheng)(sheng)活(huo)(huo)外(wai)(wai),絕大多數種(zhong)(zhong)均為(wei)(wei)(wei)(wei)(wei)海(hai)洋(yang)(yang)生(sheng)(sheng)活(huo)(huo),多數在淺(qian)海(hai),少(shao)數為(wei)(wei)(wei)(wei)(wei)深海(hai)種(zhong)(zhong),現(xian)(xian)存約11000種(zhong)(zhong),分為(wei)(wei)(wei)(wei)(wei)3個綱:水(shui)(shui)(shui)螅綱(Hydrozoa)、缽水(shui)(shui)(shui)母(mu)(mu)綱(Scyphozoa)、珊(shan)瑚(hu)(hu)綱(Anthozoa)。
刺胞(bao)動(dong)物很少能做(zuo)主動(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)移位運(yun)(yun)動(dong),運(yun)(yun)動(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)能力(li)是(shi)(shi)很有(you)(you)(you)限的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),特別是(shi)(shi)水(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型。運(yun)(yun)動(dong)是(shi)(shi)由(you)表皮肌(ji)(ji)(ji)肉(rou)(rou)細胞(bao)中肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo)所(suo)引起。例如水(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)身(shen)體(ti)可(ke)(ke)做(zuo)伸(shen)縮(suo)運(yun)(yun)動(dong),伸(shen)展(zhan)時(shi)體(ti)長可(ke)(ke)達15~20mm,收(shou)(shou)(shou)(shou)縮(suo)時(shi)體(ti)長僅(jin)0.5mm,這種伸(shen)縮(suo)是(shi)(shi)爆發(fa)式(shi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),每(mei)5~10分鐘左(zuo)右爆發(fa)一(yi)(yi)(yi)次,主要是(shi)(shi)由(you)外(wai)皮肌(ji)(ji)(ji)細胞(bao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)縱行(xing)肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo)所(suo)引起。身(shen)體(ti)一(yi)(yi)(yi)側(ce)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo)可(ke)(ke)引起身(shen)體(ti)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)彎曲(qu)(qu)。有(you)(you)(you)時(shi)靠彎曲(qu)(qu)身(shen)體(ti)及觸(chu)手并與(yu)基盤的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)交(jiao)替附著而(er)做(zuo)翻斛斗式(shi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)運(yun)(yun)動(dong)。基盤處粘細胞(bao)可(ke)(ke)分泌(mi)大量(liang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)氣(qi)泡,可(ke)(ke)使水(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)在(zai)水(shui)(shui)(shui)(shui)(shui)面(mian)上做(zuo)短(duan)暫的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)漂浮(fu)。缽水(shui)(shui)(shui)(shui)(shui)母(mu)類(lei)和珊瑚類(lei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)已與(yu)表皮細胞(bao)分離形(xing)成(cheng)(cheng)(cheng)獨(du)立的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)一(yi)(yi)(yi)層肌(ji)(ji)(ji)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei),例如水(shui)(shui)(shui)(shui)(shui)母(mu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)在(zai)下(xia)傘(san)(san)(san)面(mian)及傘(san)(san)(san)緣(yuan)形(xing)成(cheng)(cheng)(cheng)薄薄的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)一(yi)(yi)(yi)層肌(ji)(ji)(ji)肉(rou)(rou)環,有(you)(you)(you)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)被(bei)(bei)輻(fu)管分離成(cheng)(cheng)(cheng)片狀,其纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)有(you)(you)(you)橫紋,它(ta)(ta)們做(zuo)有(you)(you)(you)規律的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo),使傘(san)(san)(san)面(mian)有(you)(you)(you)節奏的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo)運(yun)(yun)動(dong)。當(dang)傘(san)(san)(san)緣(yuan)收(shou)(shou)(shou)(shou)縮(suo)時(shi),傘(san)(san)(san)緣(yuan)內的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)被(bei)(bei)噴出,由(you)于反(fan)作(zuo)用力(li)而(er)推動(dong)水(shui)(shui)(shui)(shui)(shui)母(mu)體(ti)向上運(yun)(yun)動(dong),當(dang)傘(san)(san)(san)及傘(san)(san)(san)緣(yuan)肌(ji)(ji)(ji)肉(rou)(rou)舒張,被(bei)(bei)壓縮(suo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)中膠(jiao)層的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)彈性,使傘(san)(san)(san)又(you)恢(hui)復了原(yuan)形(xing),水(shui)(shui)(shui)(shui)(shui)又(you)重新進入傘(san)(san)(san)緣(yuan)內,身(shen)體(ti)下(xia)沉,但由(you)于收(shou)(shou)(shou)(shou)縮(suo)比舒張要快,所(suo)以水(shui)(shui)(shui)(shui)(shui)母(mu)還是(shi)(shi)可(ke)(ke)以向上垂(chui)(chui)直(zhi)運(yun)(yun)動(dong)。水(shui)(shui)(shui)(shui)(shui)母(mu)類(lei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)垂(chui)(chui)直(zhi)運(yun)(yun)動(dong)在(zai)有(you)(you)(you)緣(yuan)膜(mo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)母(mu)可(ke)(ke)以看的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)更為清(qing)楚。一(yi)(yi)(yi)旦肌(ji)(ji)(ji)肉(rou)(rou)停止收(shou)(shou)(shou)(shou)縮(suo),水(shui)(shui)(shui)(shui)(shui)母(mu)就會自然(ran)下(xia)沉。其水(shui)(shui)(shui)(shui)(shui)平方(fang)向的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)運(yun)(yun)動(dong)多(duo)是(shi)(shi)被(bei)(bei)動(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),多(duo)是(shi)(shi)由(you)于水(shui)(shui)(shui)(shui)(shui)流及風力(li)所(suo)推動(dong)。又(you)例如在(zai)珊瑚類(lei),海(hai)葵的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)肌(ji)(ji)(ji)原(yuan)纖(xian)(xian)(xian)(xian)維(wei)(wei)(wei)在(zai)隔膜(mo)上形(xing)成(cheng)(cheng)(cheng)發(fa)達的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)牽縮(suo)肌(ji)(ji)(ji),它(ta)(ta)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)(shou)縮(suo)非常有(you)(you)(you)力(li),所(suo)以當(dang)海(hai)葵固著在(zai)巖石上是(shi)(shi)很難將它(ta)(ta)取下(xia)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)。
刺胞(bao)(bao)(bao)動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)都是(shi)肉食性(xing)的(de)(de)(de)(de)(de),以(yi)浮(fu)游生(sheng)物(wu)(wu)(wu)(wu)(wu)(wu),小的(de)(de)(de)(de)(de)甲殼類(lei)、多毛類(lei)甚(shen)至小的(de)(de)(de)(de)(de)魚類(lei)為食。由(you)(you)于食物(wu)(wu)(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)機械刺激和化(hua)學(xue)(xue)刺激,引起(qi)水(shui)螅類(lei)動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)伸長觸手,并(bing)放出(chu)刺絲囊以(yi)纏繞(rao)、麻痹、毒(du)殺捕獲(huo)物(wu)(wu)(wu)(wu)(wu)(wu),再將食物(wu)(wu)(wu)(wu)(wu)(wu)送入(ru)口(kou)中。口(kou)區(qu)腺(xian)細(xi)(xi)胞(bao)(bao)(bao)分(fen)泌的(de)(de)(de)(de)(de)粘(zhan)液有(you)(you)利于食物(wu)(wu)(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)吞(tun)咽,食物(wu)(wu)(wu)(wu)(wu)(wu)進入(ru)胃(wei)腔(qiang)(qiang)后(hou),胃(wei)層的(de)(de)(de)(de)(de)腺(xian)細(xi)(xi)胞(bao)(bao)(bao)開始(shi)分(fen)泌蛋白(bai)酶,分(fen)解、消化(hua)食物(wu)(wu)(wu)(wu)(wu)(wu)使之(zhi)(zhi)形成許(xu)多多肽,同時在胃(wei)腔(qiang)(qiang)中由(you)(you)于營養(yang)(yang)肌(ji)肉細(xi)(xi)胞(bao)(bao)(bao)的(de)(de)(de)(de)(de)鞭(bian)毛運動(dong),食物(wu)(wu)(wu)(wu)(wu)(wu)得以(yi)混(hun)合(he)與推動(dong)。經(jing)這(zhe)種(zhong)細(xi)(xi)胞(bao)(bao)(bao)外消化(hua)之(zhi)(zhi)后(hou),開始(shi)細(xi)(xi)胞(bao)(bao)(bao)內(nei)(nei)(nei)的(de)(de)(de)(de)(de)消化(hua)過程,營養(yang)(yang)肌(ji)肉細(xi)(xi)胞(bao)(bao)(bao)的(de)(de)(de)(de)(de)偽(wei)足吞(tun)噬食物(wu)(wu)(wu)(wu)(wu)(wu)顆粒,在細(xi)(xi)胞(bao)(bao)(bao)內(nei)(nei)(nei)形成大(da)量的(de)(de)(de)(de)(de)食物(wu)(wu)(wu)(wu)(wu)(wu)泡,經(jing)過酸性(xing)及(ji)堿性(xing)的(de)(de)(de)(de)(de)化(hua)學(xue)(xue)過程之(zhi)(zhi)后(hou),營養(yang)(yang)物(wu)(wu)(wu)(wu)(wu)(wu)質由(you)(you)細(xi)(xi)胞(bao)(bao)(bao)的(de)(de)(de)(de)(de)擴(kuo)散作(zuo)用輸送到全(quan)身。缽(bo)水(shui)母(mu)類(lei)及(ji)珊瑚(hu)類(lei)胃(wei)腔(qiang)(qiang)結構比較復雜。缽(bo)水(shui)母(mu)的(de)(de)(de)(de)(de)胃(wei)腔(qiang)(qiang)中有(you)(you)各種(zhong)輻管及(ji)環(huan)管,胃(wei)囊中有(you)(you)內(nei)(nei)(nei)胚層起(qi)源的(de)(de)(de)(de)(de)胃(wei)絲;珊瑚(hu)類(lei)的(de)(de)(de)(de)(de)胃(wei)腔(qiang)(qiang)被許(xu)多隔(ge)(ge)膜(mo)分(fen)隔(ge)(ge)成許(xu)多小室,隔(ge)(ge)膜(mo)上有(you)(you)隔(ge)(ge)膜(mo)絲。胃(wei)絲及(ji)隔(ge)(ge)膜(mo)絲中含有(you)(you)大(da)量的(de)(de)(de)(de)(de)刺細(xi)(xi)胞(bao)(bao)(bao)及(ji)腺(xian)細(xi)(xi)胞(bao)(bao)(bao),它們是(shi)將食物(wu)(wu)(wu)(wu)(wu)(wu)吞(tun)入(ru)胃(wei)腔(qiang)(qiang)之(zhi)(zhi)后(hou)才(cai)殺死及(ji)消化(hua)。消化(hua)后(hou)的(de)(de)(de)(de)(de)營養(yang)(yang)物(wu)(wu)(wu)(wu)(wu)(wu)通過各種(zhong)管道輸送到全(quan)身,未(wei)消化(hua)的(de)(de)(de)(de)(de)食物(wu)(wu)(wu)(wu)(wu)(wu)殘渣仍(reng)由(you)(you)口(kou)排出(chu)。糖(tang)元及(ji)脂肪是(shi)腔(qiang)(qiang)腸動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)的(de)(de)(de)(de)(de)主要貯存物(wu)(wu)(wu)(wu)(wu)(wu)。刺胞(bao)(bao)(bao)動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)中許(xu)多種(zhong)類(lei),特別是(shi)海(hai)洋中的(de)(de)(de)(de)(de)造礁珊瑚(hu)類(lei),體內(nei)(nei)(nei)均(jun)有(you)(you)共生(sheng)的(de)(de)(de)(de)(de)藻類(lei),如動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)黃(huang)藻、腰鞭(bian)毛藻之(zhi)(zhi)類(lei)。藻類(lei)能進行光合(he)作(zuo)用,產生(sheng)甘油(you)、脂肪、糖(tang)及(ji)脯(fu)氨酸等,并(bing)提供給刺胞(bao)(bao)(bao)動(dong)物(wu)(wu)(wu)(wu)(wu)(wu)作(zuo)為其補充營養(yang)(yang)。這(zhe)將在珊瑚(hu)綱中做進一步的(de)(de)(de)(de)(de)敘(xu)述。
刺(ci)胞(bao)動物(wu)(wu)沒(mei)有專(zhuan)門的(de)呼(hu)吸及排(pai)(pai)泄器官,由于身(shen)體(ti)是由兩層(ceng)細胞(bao)圍繞(rao)胃循(xun)環(huan)(huan)腔所組成,并(bing)通(tong)過口使(shi)胃腔與(yu)外界(jie)相通(tong),實際(ji)上體(ti)壁(bi)的(de)兩層(ceng)細胞(bao)均與(yu)外界(jie)環(huan)(huan)境接觸(chu),所以呼(hu)吸與(yu)排(pai)(pai)泄作用可(ke)以由體(ti)壁(bi)細胞(bao)直接獨立(li)進行。出、入口及胃腔的(de)水(shui)流可(ke)以攜帶入新鮮的(de)氧氣,并(bing)帶走代謝產(chan)物(wu)(wu)。刺(ci)胞(bao)動物(wu)(wu)的(de)主要含氮廢(fei)物(wu)(wu)是氨。
刺(ci)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)是(shi)(shi)(shi)最(zui)(zui)早出現神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)結(jie)(jie)(jie)構(gou)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)多(duo)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)。神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)結(jie)(jie)(jie)構(gou)原始,是(shi)(shi)(shi)由(you)(you)(you)(you)雙極(ji)(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)、多(duo)極(ji)(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)及(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)纖(xian)維(wei)聯(lian)(lian)合成(cheng)(cheng)(cheng)(cheng)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)叢或(huo)(huo)(huo)(huo)(huo)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang),一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)般(ban)位(wei)(wei)(wei)于(yu)(yu)外(wai)(wai)(wai)表(biao)(biao)(biao)皮細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)基部(bu)肌(ji)肉層之(zhi)(zhi)外(wai)(wai)(wai),呈(cheng)網(wang)(wang)狀(zhuang)分(fen)布,故稱(cheng)(cheng)網(wang)(wang)狀(zhuang)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)系(xi)統(tong)(netnervous system)。由(you)(you)(you)(you)于(yu)(yu)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)可(ke)向各個(ge)(ge)(ge)(ge)方(fang)(fang)向傳(chuan)(chuan)(chuan)(chuan)導(dao),也稱(cheng)(cheng)為漫散神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)系(xi)統(tong)(diffusenervous system)。水(shui)(shui)(shui)(shui)(shui)螅(xi)就(jiu)(jiu)只有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang),但大多(duo)數腔(qiang)腸(chang)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)除(chu)了(le)表(biao)(biao)(biao)皮的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang)之(zhi)(zhi)外(wai)(wai)(wai),在(zai)(zai)(zai)胃層的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)基部(bu)也有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang),這兩(liang)(liang)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang)或(huo)(huo)(huo)(huo)(huo)是(shi)(shi)(shi)完全獨立的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),或(huo)(huo)(huo)(huo)(huo)有(you)(you)(you)(you)(you)(you)(you)(you)纖(xian)維(wei)相(xiang)聯(lian)(lian)。1971年Westfall等(deng)首先(xian)證(zheng)明(ming)(ming)了(le)水(shui)(shui)(shui)(shui)(shui)螅(xi)及(ji)其他腔(qiang)腸(chang)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)在(zai)(zai)(zai)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)之(zhi)(zhi)間(jian)(jian)、神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)與(yu)效(xiao)應(ying)器(qi)(qi)(表(biao)(biao)(biao)皮肌(ji)肉細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)、刺(ci)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)、腺細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)等(deng))之(zhi)(zhi)間(jian)(jian)也存(cun)在(zai)(zai)(zai)著突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)傳(chuan)(chuan)(chuan)(chuan)遞(di)(synaptic transmission)。即(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)沖動(dong)(dong)(dong)(dong)(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)傳(chuan)(chuan)(chuan)(chuan)導(dao)是(shi)(shi)(shi)由(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)軸(zhou)突(tu)(tu)(tu)(tu),傳(chuan)(chuan)(chuan)(chuan)遞(di)給另一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)樹(shu)突(tu)(tu)(tu)(tu)。軸(zhou)突(tu)(tu)(tu)(tu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)末端(duan)具有(you)(you)(you)(you)(you)(you)(you)(you)突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)小泡(synaptic vesicle),樹(shu)突(tu)(tu)(tu)(tu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)末端(duan)沒有(you)(you)(you)(you)(you)(you)(you)(you)。傳(chuan)(chuan)(chuan)(chuan)導(dao)時(shi)(shi),突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)小泡釋放乙(yi)酰(xian)膽堿(jian)引(yin)起(qi)(qi)(qi)后一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)興奮(fen),沖動(dong)(dong)(dong)(dong)(dong)傳(chuan)(chuan)(chuan)(chuan)出以(yi)后,乙(yi)酰(xian)膽堿(jian)被神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)末稍表(biao)(biao)(biao)面(mian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)膽堿(jian)酯(zhi)酶水(shui)(shui)(shui)(shui)(shui)解成(cheng)(cheng)(cheng)(cheng)膽堿(jian)及(ji)乙(yi)酸而解除(chu)了(le)激活作用。以(yi)后又發現腔(qiang)腸(chang)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)傳(chuan)(chuan)(chuan)(chuan)導(dao)分(fen)為兩(liang)(liang)種類(lei)型(xing)(xing)。一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)類(lei)突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)是(shi)(shi)(shi)對(dui)稱(cheng)(cheng)性(xing)(xing)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)傳(chuan)(chuan)(chuan)(chuan)導(dao)(symmetrical),即(ji)兩(liang)(liang)個(ge)(ge)(ge)(ge)或(huo)(huo)(huo)(huo)(huo)多(duo)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)末端(duan)有(you)(you)(you)(you)(you)(you)(you)(you)突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)小泡,因此(ci)沖動(dong)(dong)(dong)(dong)(dong)可(ke)以(yi)同(tong)(tong)時(shi)(shi)向兩(liang)(liang)個(ge)(ge)(ge)(ge)或(huo)(huo)(huo)(huo)(huo)幾個(ge)(ge)(ge)(ge)方(fang)(fang)向傳(chuan)(chuan)(chuan)(chuan)遞(di),這種傳(chuan)(chuan)(chuan)(chuan)導(dao)也叫非極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)傳(chuan)(chuan)(chuan)(chuan)導(dao)(nonpolarized transmission);另一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)類(lei)突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)是(shi)(shi)(shi)不對(dui)稱(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(asymmetrical),即(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)只有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)末端(duan)具突(tu)(tu)(tu)(tu)觸(chu)(chu)(chu)(chu)小泡,神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)沖動(dong)(dong)(dong)(dong)(dong)只能向一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)方(fang)(fang)向傳(chuan)(chuan)(chuan)(chuan)導(dao),因此(ci)也稱(cheng)(cheng)為有(you)(you)(you)(you)(you)(you)(you)(you)極(ji)(ji)性(xing)(xing)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)傳(chuan)(chuan)(chuan)(chuan)導(dao)(polarized transmission)。最(zui)(zui)近的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)研(yan)究(jiu)證(zheng)明(ming)(ming)刺(ci)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)非極(ji)(ji)性(xing)(xing)傳(chuan)(chuan)(chuan)(chuan)導(dao)是(shi)(shi)(shi)很普遍的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)。也有(you)(you)(you)(you)(you)(you)(you)(you)人認為刺(ci)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)兩(liang)(liang)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)是(shi)(shi)(shi)由(you)(you)(you)(you)多(duo)極(ji)(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)形成(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)非極(ji)(ji)性(xing)(xing)傳(chuan)(chuan)(chuan)(chuan)導(dao),也就(jiu)(jiu)是(shi)(shi)(shi)慢傳(chuan)(chuan)(chuan)(chuan)導(dao)系(xi)統(tong);另一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)是(shi)(shi)(shi)由(you)(you)(you)(you)雙極(ji)(ji)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)形成(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)極(ji)(ji)性(xing)(xing)傳(chuan)(chuan)(chuan)(chuan)導(dao),也就(jiu)(jiu)是(shi)(shi)(shi)快傳(chuan)(chuan)(chuan)(chuan)導(dao)系(xi)統(tong)。刺(ci)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)可(ke)以(yi)有(you)(you)(you)(you)(you)(you)(you)(you)2個(ge)(ge)(ge)(ge)、3個(ge)(ge)(ge)(ge)或(huo)(huo)(huo)(huo)(huo)多(duo)個(ge)(ge)(ge)(ge)長(chang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)突(tu)(tu)(tu)(tu)起(qi)(qi)(qi),這些(xie)突(tu)(tu)(tu)(tu)起(qi)(qi)(qi)或(huo)(huo)(huo)(huo)(huo)與(yu)感(gan)(gan)(gan)(gan)(gan)官相(xiang)聯(lian)(lian)、或(huo)(huo)(huo)(huo)(huo)與(yu)效(xiao)應(ying)器(qi)(qi)相(xiang)聯(lian)(lian)、或(huo)(huo)(huo)(huo)(huo)與(yu)其他神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)相(xiang)聯(lian)(lian)、或(huo)(huo)(huo)(huo)(huo)者是(shi)(shi)(shi)同(tong)(tong)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)同(tong)(tong)時(shi)(shi)與(yu)感(gan)(gan)(gan)(gan)(gan)官與(yu)效(xiao)應(ying)器(qi)(qi)相(xiang)聯(lian)(lian),這種多(duo)樣性(xing)(xing)說(shuo)明(ming)(ming)了(le)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)傳(chuan)(chuan)(chuan)(chuan)導(dao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)原始性(xing)(xing)。在(zai)(zai)(zai)生理(li)意義上代表(biao)(biao)(biao)了(le)高等(deng)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)所(suo)具有(you)(you)(you)(you)(you)(you)(you)(you)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)、運(yun)(yun)動(dong)(dong)(dong)(dong)(dong)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)及(ji)中(zhong)(zhong)樞神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)起(qi)(qi)(qi)始階段。此(ci)外(wai)(wai)(wai),刺(ci)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)非神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)傳(chuan)(chuan)(chuan)(chuan)導(dao),即(ji)上皮傳(chuan)(chuan)(chuan)(chuan)導(dao)也是(shi)(shi)(shi)很常見(jian)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de),例如(ru)刺(ci)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)、表(biao)(biao)(biao)皮肌(ji)肉細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)可(ke)以(yi)完全獨立于(yu)(yu)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)而被自身(shen)所(suo)控制。水(shui)(shui)(shui)(shui)(shui)母型(xing)(xing)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)結(jie)(jie)(jie)構(gou)比(bi)(bi)水(shui)(shui)(shui)(shui)(shui)螅(xi)型(xing)(xing)復(fu)雜,例如(ru)水(shui)(shui)(shui)(shui)(shui)螅(xi)水(shui)(shui)(shui)(shui)(shui)母,除(chu)了(le)傘部(bu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)網(wang)(wang)之(zhi)(zhi)外(wai)(wai)(wai),傘緣(yuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)上皮神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)分(fen)別在(zai)(zai)(zai)傘緣(yuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)上、下(xia)面(mian)集中(zhong)(zhong)形成(cheng)(cheng)(cheng)(cheng)兩(liang)(liang)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環。下(xia)面(mian)(或(huo)(huo)(huo)(huo)(huo)稱(cheng)(cheng)外(wai)(wai)(wai)面(mian))的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環更發達。缽水(shui)(shui)(shui)(shui)(shui)母類(lei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)母型(xing)(xing)多(duo)數沒有(you)(you)(you)(you)(you)(you)(you)(you)這種神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環,而是(shi)(shi)(shi)在(zai)(zai)(zai)傘緣(yuan)集中(zhong)(zhong)形成(cheng)(cheng)(cheng)(cheng)4~8個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)節(jie)(jie)。水(shui)(shui)(shui)(shui)(shui)母型(xing)(xing)個(ge)(ge)(ge)(ge)體(ti)(ti)均(jun)能表(biao)(biao)(biao)現出一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)種有(you)(you)(you)(you)(you)(you)(you)(you)節(jie)(jie)奏的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)縮(suo)運(yun)(yun)動(dong)(dong)(dong)(dong)(dong),這是(shi)(shi)(shi)由(you)(you)(you)(you)于(yu)(yu)水(shui)(shui)(shui)(shui)(shui)母的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)結(jie)(jie)(jie)構(gou)每(mei)(mei)隔(ge)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)定時(shi)(shi)間(jian)(jian)能自發地產生動(dong)(dong)(dong)(dong)(dong)作電位(wei)(wei)(wei),并經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)過(guo)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)傳(chuan)(chuan)(chuan)(chuan)導(dao)引(yin)起(qi)(qi)(qi)整(zheng)(zheng)個(ge)(ge)(ge)(ge)身(shen)體(ti)(ti)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)縮(suo)。研(yan)究(jiu)已經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)證(zheng)明(ming)(ming)這種自發的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)動(dong)(dong)(dong)(dong)(dong)作電位(wei)(wei)(wei)是(shi)(shi)(shi)由(you)(you)(you)(you)起(qi)(qi)(qi)博(bo)點的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)所(suo)引(yin)起(qi)(qi)(qi)。起(qi)(qi)(qi)博(bo)點神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan)在(zai)(zai)(zai)水(shui)(shui)(shui)(shui)(shui)螅(xi)水(shui)(shui)(shui)(shui)(shui)母存(cun)在(zai)(zai)(zai)于(yu)(yu)外(wai)(wai)(wai)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環中(zhong)(zhong),在(zai)(zai)(zai)缽水(shui)(shui)(shui)(shui)(shui)母類(lei)存(cun)在(zai)(zai)(zai)于(yu)(yu)感(gan)(gan)(gan)(gan)(gan)官神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)節(jie)(jie)中(zhong)(zhong)。而且(qie)每(mei)(mei)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)節(jie)(jie)(一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)般(ban)4~8個(ge)(ge)(ge)(ge))都(dou)有(you)(you)(you)(you)(you)(you)(you)(you)起(qi)(qi)(qi)博(bo)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)元(yuan)(yuan)(yuan)(yuan)(yuan),它(ta)(ta)是(shi)(shi)(shi)水(shui)(shui)(shui)(shui)(shui)母類(lei)有(you)(you)(you)(you)(you)(you)(you)(you)節(jie)(jie)奏博(bo)動(dong)(dong)(dong)(dong)(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)中(zhong)(zhong)心。一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)水(shui)(shui)(shui)(shui)(shui)母體(ti)(ti)似乎有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)起(qi)(qi)(qi)博(bo)點就(jiu)(jiu)足以(yi)引(yin)起(qi)(qi)(qi)身(shen)體(ti)(ti)有(you)(you)(you)(you)(you)(you)(you)(you)節(jie)(jie)奏的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)縮(suo)運(yun)(yun)動(dong)(dong)(dong)(dong)(dong),但實驗證(zheng)明(ming)(ming)多(duo)個(ge)(ge)(ge)(ge)起(qi)(qi)(qi)博(bo)點比(bi)(bi)僅有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)起(qi)(qi)(qi)博(bo)點能使收(shou)(shou)(shou)縮(suo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)節(jie)(jie)奏更有(you)(you)(you)(you)(you)(you)(you)(you)規(gui)律、更有(you)(you)(you)(you)(you)(you)(you)(you)保障、使間(jian)(jian)隔(ge)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)時(shi)(shi)間(jian)(jian)也較(jiao)短。腔(qiang)腸(chang)動(dong)(dong)(dong)(dong)(dong)物(wu)(wu)(wu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)螅(xi)型(xing)(xing)體(ti)(ti)沒有(you)(you)(you)(you)(you)(you)(you)(you)明(ming)(ming)顯的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)感(gan)(gan)(gan)(gan)(gan)官,其感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)可(ke)分(fen)布全身(shen),但觸(chu)(chu)(chu)(chu)手、口區較(jiao)為豐富(fu)。水(shui)(shui)(shui)(shui)(shui)母型(xing)(xing)個(ge)(ge)(ge)(ge)體(ti)(ti),在(zai)(zai)(zai)傘緣(yuan)具有(you)(you)(you)(you)(you)(you)(you)(you)豐富(fu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)或(huo)(huo)(huo)(huo)(huo)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)器(qi)(qi)官。感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)體(ti)(ti)都(dou)是(shi)(shi)(shi)具纖(xian)毛的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)。感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)器(qi)(qi)官包(bao)括眼點及(ji)平(ping)衡囊(nang)。眼點是(shi)(shi)(shi)由(you)(you)(you)(you)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)構(gou)成(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)杯狀(zhuang)物(wu)(wu)(wu),內(nei)(nei)有(you)(you)(you)(you)(you)(you)(you)(you)色素顆(ke)粒分(fen)布,它(ta)(ta)對(dui)光線或(huo)(huo)(huo)(huo)(huo)有(you)(you)(you)(you)(you)(you)(you)(you)正趨性(xing)(xing),即(ji)有(you)(you)(you)(you)(you)(you)(you)(you)光時(shi)(shi)游(you)向水(shui)(shui)(shui)(shui)(shui)面(mian)。或(huo)(huo)(huo)(huo)(huo)對(dui)光有(you)(you)(you)(you)(you)(you)(you)(you)負(fu)趨性(xing)(xing),即(ji)有(you)(you)(you)(you)(you)(you)(you)(you)光時(shi)(shi)下(xia)沉水(shui)(shui)(shui)(shui)(shui)底,無光或(huo)(huo)(huo)(huo)(huo)弱光時(shi)(shi)浮向水(shui)(shui)(shui)(shui)(shui)面(mian)。平(ping)衡囊(nang)在(zai)(zai)(zai)水(shui)(shui)(shui)(shui)(shui)螅(xi)水(shui)(shui)(shui)(shui)(shui)母結(jie)(jie)(jie)構(gou)簡單,在(zai)(zai)(zai)緣(yuan)膜基部(bu)或(huo)(huo)(huo)(huo)(huo)下(xia)傘面(mian)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環(即(ji)外(wai)(wai)(wai)神(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)(shen)經(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)(jing)環)處形成(cheng)(cheng)(cheng)(cheng)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)個(ge)(ge)(ge)(ge)小囊(nang),囊(nang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)內(nei)(nei)壁有(you)(you)(you)(you)(you)(you)(you)(you)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao),細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)上也有(you)(you)(you)(you)(you)(you)(you)(you)纖(xian)毛。囊(nang)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)底部(bu)有(you)(you)(you)(you)(you)(you)(you)(you)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)鈣質結(jie)(jie)(jie)石。它(ta)(ta)是(shi)(shi)(shi)一(yi)(yi)(yi)(yi)(yi)(yi)(yi)(yi)種重力感(gan)(gan)(gan)(gan)(gan)受器(qi)(qi)。當傘緣(yuan)傾(qing)斜時(shi)(shi),結(jie)(jie)(jie)石與(yu)感(gan)(gan)(gan)(gan)(gan)覺(jue)(jue)(jue)細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)纖(xian)毛接觸(chu)(chu)(chu)(chu),并刺(ci)激纖(xian)毛細(xi)(xi)(xi)(xi)(xi)(xi)(xi)胞(bao)(bao)(bao)(bao)(bao)(bao)(bao)以(yi)產生動(dong)(dong)(dong)(dong)(dong)作電位(wei)(wei)(wei),抑制了(le)該側肌(ji)肉纖(xian)維(wei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)收(shou)(shou)(shou)縮(suo),通過(guo)肌(ji)肉收(shou)(shou)(shou)縮(suo)再調整(zheng)(zheng)身(shen)體(ti)(ti)使恢復(fu)平(ping)衡位(wei)(wei)(wei)置(zhi)。缽水(shui)(shui)(shui)(shui)(shui)母類(lei)的(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)(de)平(ping)衡囊(nang)結(jie)(jie)(jie)構(gou)更復(fu)雜,將在(zai)(zai)(zai)有(you)(you)(you)(you)(you)(you)(you)(you)關節(jie)(jie)中(zhong)(zhong)敘述
無(wu)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)及有(you)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)在(zai)(zai)腔(qiang)腸(chang)動(dong)(dong)物中(zhong)(zhong)都(dou)(dou)是(shi)(shi)很普遍的(de)(de)(de)(de)(de)。無(wu)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)主要(yao)(yao)形(xing)(xing)式(shi)是(shi)(shi)出(chu)芽生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi),特別是(shi)(shi)在(zai)(zai)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型更為常見。例如水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)出(chu)芽時從身(shen)體(ti)(ti)(ti)(ti)的(de)(de)(de)(de)(de)靠基部通過(guo)體(ti)(ti)(ti)(ti)壁及胃(wei)腔(qiang)的(de)(de)(de)(de)(de)向外(wai)(wai)突出(chu),再(zai)長(chang)出(chu)觸手與口(kou)(kou)(kou)即(ji)形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)芽體(ti)(ti)(ti)(ti),以(yi)后(hou)芽體(ti)(ti)(ti)(ti)與母(mu)體(ti)(ti)(ti)(ti)分(fen)離即(ji)形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)新(xin)的(de)(de)(de)(de)(de)個(ge)體(ti)(ti)(ti)(ti)。但(dan)在(zai)(zai)藪枝螅(xi)(xi)(Obelia)所(suo)形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)芽體(ti)(ti)(ti)(ti)與母(mu)體(ti)(ti)(ti)(ti)不分(fen)離則(ze)形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)了群(qun)體(ti)(ti)(ti)(ti)。其(qi)(qi)次,也可以(yi)通過(guo)分(fen)裂(lie)方式(shi)進(jin)行無(wu)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi),主要(yao)(yao)發(fa)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)在(zai)(zai)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型,例如海葵可以(yi)縱分(fen)裂(lie),缽水(shui)(shui)(shui)(shui)(shui)(shui)母(mu)的(de)(de)(de)(de)(de)幼(you)體(ti)(ti)(ti)(ti)以(yi)橫(heng)分(fen)裂(lie)進(jin)行無(wu)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)。此(ci)外(wai)(wai)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型一(yi)般具有(you)很強的(de)(de)(de)(de)(de)再(zai)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)能力,例如,將水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)切成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)數(shu)段(duan)(duan),條件合宜時每(mei)段(duan)(duan)都(dou)(dou)可以(yi)再(zai)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)一(yi)個(ge)新(xin)的(de)(de)(de)(de)(de)個(ge)體(ti)(ti)(ti)(ti),再(zai)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)時口(kou)(kou)(kou)與反口(kou)(kou)(kou)端的(de)(de)(de)(de)(de)極性(xing)不變,但(dan)口(kou)(kou)(kou)端的(de)(de)(de)(de)(de)再(zai)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)速(su)度比反口(kou)(kou)(kou)端迅(xun)速(su)。所(suo)以(yi)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型的(de)(de)(de)(de)(de)再(zai)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)現(xian)(xian)象也被認為是(shi)(shi)無(wu)性(xing)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)一(yi)種(zhong)方式(shi)。有(you)些生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)出(chu)現(xian)(xian)在(zai)(zai)多(duo)數(shu)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型及所(suo)有(you)的(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)(shui)母(mu)型,除少數(shu)種(zhong)類例如水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)為雌(ci)雄(xiong)同體(ti)(ti)(ti)(ti)之外(wai)(wai),絕大多(duo)數(shu)種(zhong)類為雌(ci)雄(xiong)異體(ti)(ti)(ti)(ti)(或(huo)異群(qun)體(ti)(ti)(ti)(ti))。生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)細(xi)(xi)(xi)胞(bao)(bao)(bao)來源于(yu)(yu)(yu)間(jian)細(xi)(xi)(xi)胞(bao)(bao)(bao),然后(hou)遷移到固(gu)定的(de)(de)(de)(de)(de)位(wei)置上形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)腺。水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)蟲(chong)綱的(de)(de)(de)(de)(de)動(dong)(dong)物生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)腺來源于(yu)(yu)(yu)表(biao)皮(pi)層(ceng)(ceng),例如水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi),水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)水(shui)(shui)(shui)(shui)(shui)(shui)母(mu)的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)腺位(wei)于(yu)(yu)(yu)放射管(guan)下或(huo)垂唇周(zhou)圍,但(dan)都(dou)(dou)是(shi)(shi)來源于(yu)(yu)(yu)表(biao)皮(pi)層(ceng)(ceng)細(xi)(xi)(xi)胞(bao)(bao)(bao)。缽水(shui)(shui)(shui)(shui)(shui)(shui)母(mu)綱的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)細(xi)(xi)(xi)胞(bao)(bao)(bao)起(qi)源于(yu)(yu)(yu)胃(wei)層(ceng)(ceng)位(wei)于(yu)(yu)(yu)胃(wei)囊(nang)低部。珊瑚綱的(de)(de)(de)(de)(de)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)細(xi)(xi)(xi)胞(bao)(bao)(bao)是(shi)(shi)由胃(wei)腔(qiang)中(zhong)(zhong)的(de)(de)(de)(de)(de)隔膜上發(fa)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng),也是(shi)(shi)內(nei)胚(pei)(pei)(pei)層(ceng)(ceng)來源。腔(qiang)腸(chang)動(dong)(dong)物只有(you)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)腺,沒有(you)出(chu)現(xian)(xian)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)導管(guan)及生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)附屬(shu)腺,生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)細(xi)(xi)(xi)胞(bao)(bao)(bao)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)熟之后(hou)由口(kou)(kou)(kou)排出(chu),或(huo)由體(ti)(ti)(ti)(ti)壁破裂(lie)而釋(shi)放。受精(jing)作用依不同的(de)(de)(de)(de)(de)種(zhong)而異,或(huo)在(zai)(zai)體(ti)(ti)(ti)(ti)外(wai)(wai)海水(shui)(shui)(shui)(shui)(shui)(shui)中(zhong)(zhong)進(jin)行,或(huo)在(zai)(zai)垂管(guan)的(de)(de)(de)(de)(de)表(biao)面,或(huo)在(zai)(zai)胃(wei)腔(qiang)內(nei)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)腺的(de)(de)(de)(de)(de)部位(wei)進(jin)行。卵(luan)裂(lie)是(shi)(shi)完全的(de)(de)(de)(de)(de),形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)中(zhong)(zhong)空的(de)(de)(de)(de)(de)囊(nang)胚(pei)(pei)(pei),經(jing)移入(ru)法或(huo)內(nei)陷法形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)原(yuan)腸(chang)胚(pei)(pei)(pei),結果形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)兩層(ceng)(ceng)細(xi)(xi)(xi)胞(bao)(bao)(bao),即(ji)兩個(ge)胚(pei)(pei)(pei)層(ceng)(ceng),內(nei)部成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)團的(de)(de)(de)(de)(de)細(xi)(xi)(xi)胞(bao)(bao)(bao)為內(nei)胚(pei)(pei)(pei)層(ceng)(ceng),將來形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)體(ti)(ti)(ti)(ti)的(de)(de)(de)(de)(de)胃(wei)層(ceng)(ceng),外(wai)(wai)表(biao)的(de)(de)(de)(de)(de)一(yi)層(ceng)(ceng)為外(wai)(wai)胚(pei)(pei)(pei)層(ceng)(ceng),將來形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)體(ti)(ti)(ti)(ti)的(de)(de)(de)(de)(de)表(biao)皮(pi)層(ceng)(ceng)。實心(xin)的(de)(de)(de)(de)(de)原(yuan)腸(chang)胚(pei)(pei)(pei)迅(xun)速(su)延(yan)長(chang),體(ti)(ti)(ti)(ti)表(biao)出(chu)現(xian)(xian)纖(xian)毛(mao),形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)了自由游(you)泳(yong)的(de)(de)(de)(de)(de)浮浪幼(you)蟲(chong)(planula)。浮浪幼(you)蟲(chong)早(zao)期(qi)沒有(you)口(kou)(kou)(kou)及胃(wei)腔(qiang),游(you)泳(yong)一(yi)段(duan)(duan)時間(jian)之后(hou),固(gu)著在(zai)(zai)水(shui)(shui)(shui)(shui)(shui)(shui)草、巖石(shi)或(huo)其(qi)(qi)他物體(ti)(ti)(ti)(ti)上發(fa)育(yu)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)型體(ti)(ti)(ti)(ti),或(huo)再(zai)經(jing)過(guo)出(chu)芽生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)殖(zhi)(zhi)(zhi)(zhi)(zhi)形(xing)(xing)成(cheng)(cheng)(cheng)(cheng)(cheng)(cheng)群(qun)體(ti)(ti)(ti)(ti)。淡(dan)水(shui)(shui)(shui)(shui)(shui)(shui)生(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)(sheng)活(huo)的(de)(de)(de)(de)(de)水(shui)(shui)(shui)(shui)(shui)(shui)螅(xi)(xi)沒有(you)幼(you)蟲(chong)期(qi),其(qi)(qi)受精(jing)卵(luan)直(zhi)接(jie)發(fa)育(yu)。