马林（marlin）是一只住在大堡礁的小丑鱼。很久以前，它的配偶珊瑚以及它们所产下来大多数的卵都在一场梭子鱼的攻击中被吃掉了。因此它变得非常的紧张、神经兮兮，且过度地保护它唯一的儿子：尼莫（nemo）。尼莫的卵在那场攻击意外中经过碰撞，导致生下来的它右鳍异常的小，被称为它的“幸运鳍”，但也因为如此，马林更是担心尼莫的游泳能力。尼莫上学的第一天，它的老师鲼老师（mr.ray）带着它和其它学生们一起去校外教学。尼莫到了大堡礁的边缘以后，就和同学们大胆的冒险游离礁石区，游到了他们口中的"屁屁"—一艘人类的船底下，碰到了那艘船的底部。马林赶到以后非常的生气，但尼莫却在这个时候被一位潜水员给捉了去，潜水员还帮马林拍了一张照。潜水员将尼莫带上船以后就开船消失了。马林情急之下慌张地游出了大堡礁，一路上寻找帮助。它遇到了一只个性天真、乐观却拥有短暂性失忆症的拟刺尾鲷：多莉（dory）。在寻找尼莫的途中，它们遇到了三只“想要吃素”的鲨鱼：布鲁斯（bruce）、安安（anchor）以及阿沈（chum），而布鲁斯将它们带到了一艘废弃的船上。在那里，马林找到了当初捉走尼莫的潜水员的蛙镜，而上面写着潜水员的住址。经过在深海中的一番惊险旅程后，多莉终于成功地念出了蛙镜上写的字，进而得知潜水员的住处是位于澳洲的悉尼。后来它们又遇到了一群菜刀鱼，它们告诉马林要前往悉尼最快的方式是搭乘东澳洋流。它们在前往东澳洋流的途中又碰到了一群危险的水母，在穿过那群水母时它们遭到水母攻击而昏去，醒来后分别躺在一只名叫龟龟（crush）的绿蠵龟，以及它同伴们之一的龟壳上。马林在那里将它和多莉寻找尼莫一路上发生的冒险故事告诉了小海龟们，而这个故事经过口耳相传也传到了悉尼港上让鹈鹕祖哥（nigel）得知。捉走尼莫的潜水员—牙医希尔曼，将尼莫带回他在悉尼港旁诊所中的鱼缸里。在那里，尼莫遇到了住在鱼缸中的鱼群们，而它们的领导者则是一只个性顽固、名叫吉哥（gill）的镰鱼。那些鱼听到牙医要把尼莫送给他的侄女后感到很害怕，因为妲拉（darla）喜欢不停的甩动装鱼的袋子，送给她的鱼经常死于非命。也经常敲击鱼缸，片中出现的部分是因为看见海星小桃儿边敲边唱'小星星。吉哥那时想到了一个逃离鱼缸的新计划，就是让尼莫钻进滤水器，并用小石子阻住滤水器的水管。这样就能使得牙医不得不将鱼群们捞出来，亲手来清洗鱼缸。尼莫于是就带着小石子钻进了滤水器，不过却失败了，甚至差点丢了它的命。不过祖哥（nigel）跑来告诉了尼莫有关它的爸爸在**大海中寻找爱子的故事以后，尼莫就坚决带着石子再尝试一次，并且成功了。但是，这个计划后来却因为牙医买了一台自动清理的先进滤水器而宣告失败。后来，马林和多莉又经历了一场冒险：它们被一只巨大的鲸鱼给吞了进去，但后来却借着鲸鱼呼吸的气体交换被“喷了出来”。被喷出来之后，它们就成功抵达了悉尼，差点被其中一只鹈鹕当成早餐，幸好因为噎到吐了出来，祖哥认出了它们，祖哥于是就将马林和多莉带到了牙医的办公室。不过，牙医却正好要将尼莫送给妲拉，而尼莫就装死，希望能够借此被冲到马桶而排放到大海中，可是牙一走进厕所，但他的举动阵惊了鱼群-他打算将它丢进垃圾桶!马林看到后，就以为尼莫真的死了。惊恐的马林拉了祖哥的蛇头让他飞进牙医的办公室，造成了一场混乱，吉哥于是趁机将尼莫《海底总动员》剧照(26张)送进了漱口池的水管中，顺利的流向了大海。马林因此而感到非常伤心，决定自己一个人回家。多莉后来则碰到了被冲到大海中的尼莫，而鉴于它的短暂失忆症，使得多莉完全不记得有关马林的事，于是就帮助尼莫一起寻找那位它根本不记得的“马林”。后来，多莉在看到悉尼海底下水道上“sydney”的字样后又恢复了记忆，于是就帮助尼莫找到了它的爸爸。马林在看到它的儿子安然无恙后感到很放心，不过不久之后，多莉却和一群石斑鱼被一个大鱼网给捞走了。尼莫在告诉它的爸爸它必须要放心让尼莫去飞之后，就钻进了鱼网中，和多莉一起帮助那群鱼逃离鱼网。尼莫于是就用了吉哥教它的方法：“尽力往下游”，起出马林不希望他这么做，深怕因为失败而让尼莫送了命，但尼莫不顾马林反对，成功的破坏了鱼网。多莉、马林和尼莫之后就回到了大堡礁，马林对尼莫也变得比较放心了。尼莫在上学前拥抱了它的爸爸，告诉马林“我爱你”，而马林也以相同的话回了尼莫。于是，尼莫和它的同学，以及交换学生—龟龟的儿子小古（squirt），就和雷老师一同出游了。故事结束。出游时的情景成为本片演职员表动画，连皮克斯上一部电影'怪兽电力公司"中的大眼仔也出现了。演职员表跑完后，还播放了一小段后传：后来鱼缸的自动滤水器也坏了，而尼莫当初丢进去的小石子于是就起了效用，鱼缸中的鱼儿们也就顺利的逃到了大海中，只不过它们却还被装在当初牙医使用的小塑胶袋中。最后，豚豚（bloat）就说道：“现在呢？（"now what?翻译：
ma lin(marlin)** a live in great barrier reef clown f**h.a long time ago,itsspouse coral and their production down most of the eggs in a pike attackwas eaten.so it becomes very tense,nervous,and excessive protection itonly son:nimmo(nemo).nemo eggs in the attack in the accident after the coll**ion,resulting in born it right fin very small,known as the"lucky",butalso because of th**,ma lin was even worried nemo swimming ability.nemo's first day of school,the teacher ray teacher(mr.ray)took it andother students go off campus teaching.after nimodipine to the edge of great barrier reef,and the students bold adventure free reef area,swim totheir mouth"fart"-a human bottom,met the ship bottom.ma lin arrivedafter the very angry,but nemo ** at th** time was a diver to catch up to,the divers also help ma lin took a picture.divers will later nemo brought aboard sailed away.
marin panic nervous swam out of the great barrier reef,on the way to seek help.it had a quasi acanthuridae a naive,optim**tic personality hastransient amnesia:dolly(dory).on the way to finding nemo,they met three"to be"shark:bruce(bruce),an an(anchor)and shen(chum),while bruce took them to an abandoned ship.there,ma lin found the originalcatch goggles go nimodipine diver,and write the diver.after deep in the sea a thrilling journey,dolly was successfully read out the frog mirrorwriting,so that divers place ** located in sydney australia.then they met a group of cooking saury,they told ma lin to go to sydney the fastest way ** to take the east australian current.they met a group of dangerous jellyf**hand on the way to the east australian current,in through the swarms ofjellyf**h jellyf**h attack while they were away,wake up lying on a namedturtle(crush)of the green turtle,turtle shell and one of its peers.ma linwhere will it and dolly finding nemo along the way,adventure story toldsmall turtles,and the story after teach orally were also introduced into sydney harbor for pelican progenitor brother(nigel)that.
catch nemo diver-dent**t hillman,will be back in sydney he nemo harborclinics in aquariums.there,nemo meets in aquarium f**h,and their leader** a personality stubborn,named ji brother(gill)** a f**h.those f**h hear the dent**t to nemo to h** niece was very afraid,because daala(darla)lovekept swinging f**h bag,g**e her the f**h often die an untimely on.often af**h tank,in part because see starf**h small peach knock sang 'little star".her brother was thought out a new plan to escape from the f**h tank,** to allow nemo drilling water filter,and with the small stones to block water filterpipe.allowing a dent**t had to f**h them out,had to clean the tank.nimmo then took the small stones into the water filter,but failed,and nearly lost h**life.but fathers brother(nigel)came to tell again about it for h** son in a vast expanse of water in the father's story,nemo firmly with stones to try again,and success.however,the plan was for the dent**t bought an automatic cleaning of the advanced water filter failed.
later,ma lin and dolly was an adventure:they are a huge whale to swallowit,but by the whale breathing gas exchange **"spouted out".after beingsprayed out,they successfully arrived in sydney,almost ** one a pelican a**reakfast,but choked to spit it out,father brother recognized their father**rother,so will ma lin and dolly brought to the dent**t's office.however,the dent**t ** just to nemo to daala,and nimodipine was dead,and hope to berushed to the toilet and d**charged into the sea,but the tooth into the toilet,but h** move surpr**ed f**h-he's going to throw it into the dustbin!after ma lin see,think nemo really dead.frightened malinla zu brother-let him fly into the dent**t's office,resulting in a mess,ji brother and took the opportunity to nimmo"finding nemo"still(26 zhang)to gargle pool water,smooth flow to the sea.
ma lin felt very sad,decided to go home by himself.dolly later met washedinto the sea of nimodipine,and in view of its transient amnesia,the dollydoesn't remember anything about ma lin,so he helps nemo together to find that it doesn't remember"ma lin".later,in the sydney subsea sewerdolly saw"sydney"and then returned to memory,and then help nemofound its father.ma lin see it son safe and sound after to feel at ease,butsoon after,dolly and a group of f**h ** a f**h net to get away. nemo after telling h** father it must let nemo to fly,and got into the net,and dollytogether to help the f**h from escaping from the net. nimmo then took jibrother teach it method: "try to swim down",the ma lin don't want him to do so,fearing failure and let nimmo out,but nimmo over ma lin's objections,succeeded in d**rupting the nets.