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今集將會講下海洋入面既哺乳類動物
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![](https://cdn.lihkg.com/assets/faces/normal/hoho.gif)
由於哺乳類無一個好複雜既綱,當中既分類千絲萬縷,所以大家唔介意既話我就無視分類,用統稱去歸納
![](https://cdn.lihkg.com/assets/faces/normal/adore.gif)
![](https://cdn.lihkg.com/assets/faces/normal/adore.gif)
![](https://cdn.lihkg.com/assets/faces/normal/adore.gif)
![](https://www.volusia.org/core/fileparse.php/4202/urlt/Bottlenose-Dolphins.jpg)
![](http://i.imgur.com/Dkhgy.gif)
![](https://media.giphy.com/media/26gssIytJvy1b1THO/source.gif)
![](http://www.gifbin.com/bin/102013/1383326929_cute_curious_seal_pup.gif)
![](http://img42.laughinggif.com/pic/HTTPS9tZWRpYS5naXBoeS5jb20vbWVkaWEvcmxrcEFtWDNnYUxXRS9naXBoeS5naWYlog.gif)
唔係想做環保拎,但無可否認海洋哺乳類對個海好重要,好多都比人視為keystone species(一個關鍵物種,無左呢家可以一家累三或以上家)。雖然如此,好多物種都已經瀕危,其實係一個好sad既事實。
由海上陸地,再番落海
"由海上陸地,再番落海"講緊既就係海洋哺乳類既來源:先係魚,到上陸地成為4腳獸,再去到成為哺乳類,再番落海生活。所以點解佢地某程度上有陸上動物既支架/外型,就係因為咁。
以鯨魚為例
![](http://evolution.berkeley.edu/evolibrary/images/evograms/whale_evo.jpg)
在此聲明所有進化學說都係有爭議性既命題,所以非常歡迎大家討論(最好有埋source)
鯨魚
![](http://i.imgur.com/J0Sb8yR.gif)
鯨魚大致上可以分兩種,有牙(Odontocetes)同無牙(Mysticetes)。無牙既鯨魚有個叫Baleen Plates既結構,好似一把梳咁,以Filter-feeding方式食浮游生物。
![](http://www.whalesforever.com/images/1.jpg)
![](http://stories.anmm.gov.au/cetacean-evolution/wp-content/uploads/sites/9/2014/03/shutterstock_120146803.jpg)
有牙既鯨魚例如白鯨,主要捕食其他大型海洋生物(魚,鯊魚)
有啲鯨魚什至有其他結構例如角(獨角鯨),超聲波定位(白鯨)幫助搵食
![](https://c402277.ssl.cf1.rackcdn.com/photos/5905/images/story_full_width/HI_232813_Paul_Nicklen_National_Geographic_Stock_WWF_Canada.jpg?1387810140)
![](http://www.factzoo.com/sites/all/img/mammals/whales/beluga-fins-out.jpg)
佢地係繁殖季節時會"唱歌",其實就係發出一啲聲音去吸引異性。以聲音去溝通其實係海洋世界好普遍,因為聲音係水中傳得好快好遠。
海豚
![](http://us.whales.org/sites/default/files/styles/large_carousel/public/species/orcinus_orca-robert_pitman.jpg?itok=K_xxur_4)
![](http://bestanimations.com/Animals/Mammals/Dolphins/dolphin/dolphin-jumping-animated-gif-5.gif)
![](http://media-channel.nationalgeographic.com/media/uploads/photos/content/photo/2015/01/30/KillerWhale_01_IPredator.jpg)
除左大家成日見到既海豚外,殺人"鯨"其實都係歸納做海豚。佢地分佈得好廣,由極地到熱帶海域都會見到佢地。
香港代表中華白海豚
![](http://www.thatsmags.com/uploads/galleries/images/white-dolphins.jpg)
係粉紅色,因為佢地表面充滿血管。
海牛
![](http://2.bp.blogspot.com/_JK5UKiJslEQ/SxHOJtV4JcI/AAAAAAAAAKA/K_vj7RWL_88/s1600/manatee_waving.jpg)
![](https://fthmb.tqn.com/I97Q91ParLz_eLTYmbb0-WNrHpg=/768x0/filters:no_upscale()/about/145587056-57a95ba63df78cf459a2324b.jpg)
唔知點解曾經被人誤會為美人魚
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