把樹木的枝條剪斷，一段時間後，傷口旁邊會發芽，長出新枝。把樹木的斷枝插

在泥中，慢慢地，會長成另外一棵樹。這種神奇的「再生」能力，植物一般都擁

有，而人類當然是沒有。然而，不少動物失去身體某部分，亦可以重新長出，新

長成的部分，無論是外觀或功能，皆與原本的無異，這種神奇的再生能力，令人

嘖嘖稱奇！

If you cut a twig off a tree, after a while new branch will emerge by the wounded spot. If you put the broken branch in soil, it will slowly grow into another tree. Such “magical” regeneration power is possessed by most plants. Humans, on the other hand, lack such power. However, quite a few members of the animal world do possess such “magical” power. When part of their body is lost, a new one can be regenerated which is equivalent to the original in terms of appearance and function. What an amazing capacity this is!

文 Text | Candy Yau

動物「再生」的奧秘，在於有些動物受

傷後，傷口會長出胚芽，其中的細胞可發展

成多種不同類型的細胞，如骨骼、血管、神

經、軟骨等等，使該動物能再生失去的身體

部分。這種能力最早在1740年於一種稱為水

螅的水生無脊椎動物身上發現，之後科學家

陸續在多種動物身上發現這種能力，包括節

肢動物，如蜘蛛、蟹、龍蝦等，還有渦蟲、

斑馬魚等。

The secret behind such “regeneration” of animals is that upon being harmed, a blastema – a mass of cells also known as a regeneration bud – will grow out from the wound. This can then develop into different types of cells such as bone, blood vessels, nerves and cartilage, and eventually build up the lost part. This capacity was discovered

in 1740 on hydra, an aqueous invertebrate. Afterwards, scientists identified such “magic” on a variety of animals including arthropods such as spiders, crabs, lobsters as well as non-parasitic flatworms and zebrafish.

Regeneration – Magic of the Animal World

無限再生－動物之神奇能力

!!

千奇百趣大自然 Amazing Nature

飛白楓海星斷掉腕足，可在短時間內長回來。Arms of Common Starfish can be regenerated within a short period of time.

壁虎(簷蛇)斷掉尾巴後能重新長回，相信

是最廣為人知的動物再生能力。大家都聽過

一個駭人的傳聞：壁虎被捉時會斷掉尾巴，

脫落的尾巴會彈入人的耳穴中。這傳聞可說

是半真半假，現實中壁虎尾巴彈入耳穴的機

會很低，但壁虎受驚會「自斷尾巴」則是真

確的，這是一種稱為「自割」的自我防護機

制。當敵人還呆呆的看著斷掉的尾巴在彈動

時，壁虎已逃之夭夭。不久之後，壁虎新的

尾巴便會重新長出。

I t is widely known that geckos can regenerate their tails after losing them. You may have even heard a terrifying rumour that when a gecko is caught it will break its tail and, the broken tail will get into the ear of a person nearby. This is only partly true. In reality the chance of the tail getting into the ear is very low. But it is true that gecko will shed its tail when threatened. This is a self-

defence mechanism called “autotomy”. It is to attract the attention of the enemy by the twitching broken tail, while the gecko can escape. After a while, a new tail will grow.

有些海星即使被肢解，仍然可以再生。

一般海星遇上危險時會自割腕足，之後再生

折斷的腕足。本港的飛白楓海星(Archaster

typicus)再生力更強，能在短時間內長出新的

腕足，有時更會同時長出兩隻腕足，所以有

時會發現有六隻腕足、甚至七隻腕足的飛白

楓海星。海盤車(Asterias spp.)更可由一隻腕

足及五分之一的體盤，重新長成完整的一隻

海星。

Some starfish can survive amputation. Usually when a starfish encounters danger it will sacrifice an arm, which can regrow later. In Hong Kong, Common Starfish (Archaster typicus) has strong regenerative power and new arms can regrow in a short period of time – and sometimes two or three new arms will be regenerated, so that you may see Common Starfish with six

or seven arms. Asterias spp. can even regrow from a single arm and one-fifth of the central disc, back into a whole starfish.

壁虎 Geckos

海星 Starfish

壁虎的尾巴斷掉後能無限重生。圖為中國壁虎(Gekko chinensis)。The broken tail of gecko can be regenerated again and again. In the photograph is Chinese Gecko (Gekko chinensis).

動物能重新長回失去的身體部分，例如蟹失去了螯或足肢，蛻殼後能重新長出；兩棲類動物的四肢，失去後亦可再生。上圖為清白招潮蟹(Uca lactea)；下圖為大綠蛙(Odorrana chloronota)。Some animals can regenerate their lost parts. For example, if a crab loses a claw or a leg, a new one can regrow after moulting. Similarly, amphibians can also regenerate their legs. On the top is Milky Fiddler Crab (Uca lactea) and on the botton is Green Cascade Frog (Odorrana chloronota).

近年，科學家發現非洲刺毛鼠(Acomys

spp.)有再生受損身體組織的能力，這是首

度在哺乳動物身上發現這種能力。若然被獵

食者逮著，牠們可自割一大塊皮毛及部分耳

朵，讓自己逃脫後，失去的身體部分會再長

出來。和人類不同，牠們可再生毛囊、皮膚

及軟骨等，所以再生部分並不會留下疤痕。

科學家已在動物身上找到一些和再生能力

有關的基因，非洲刺毛鼠的再生能力為人類

醫學帶來一大鼓舞，或許將來人類真的有機

會擁有「再生」這種神奇能力！

In recent years, scientists have found regenerative power in African Spiny Mouse (Acomys spp.) This is the first time such an ability has been identified in mammals. When caught by a predator, it will undergo autotomy and shed a large piece of its

Scientists have also identified some genes related to regeneration of animals. The case of African Spiny Mouse brings exciting

fur and part of the ear to escape, and the lost parts can regrow later. Quite different from humans, the hair follicle, skin and cartilage of African Spiny Mouse can all be regenerated, so no scar will remain.

news. Maybe we humans will achieve such “magical” regenerative power someday!

如果一條蚯蚓斷開兩截，結果會怎樣？

有說只有頭部那邊才能生存下來，亦有說

斷開的兩截能各自變成兩條蚯蚓，原來兩種

說法都是有可能的，結果取決於多種因素，

例如是蚯蚓的物種、斷開的位置、切口是否

整齊等。研究發現，蚯蚓可重新長出頭部或

尾部，但牠們不一定要重新長回失去的頭部

或尾部亦能生存下去。因此，斷成兩截的身

軀，有可能再生失去的頭部或尾部，變成兩

條完整的蚯蚓，亦有可能變成「雙頭蚯蚓」

或「雙尾蚯蚓」，很是神奇哩！

When an earthworm is cut into two parts, what will happen? There is a saying that only the part with the head can survive while some say that each part can turn into a separate earthworm. Both are possible, depending on the species, position of the cut and whether the cut is clear. Research has found that a new head and tail can

be regenerated, and the earthworm can survive regardless of whether it loses its head or tail. Therefore, an earthworm broken into two parts can become two new earthworms, or in some cases, can turn into earthworms with two heads or two tails! How intriguing!

蚯蚓 Earthworm

非洲刺毛鼠 Afrian Spiny Mouse

兩棲類動物都有再生能力，尤其是有尾的

兩棲類，其中的墨西哥鈍口螈(Ambystoma

mexicanum)，更擁有超強再生能力，牠們的

腦部、眼睛、心臟、四肢等等重要器官，統

統都可再生。更甚者是四肢癱瘓後，能夠長

出新的神經，回復活動能力！

All amphibians, particularly those with a tail, have the ability to regenerate their body parts. Mexican Axolotl (Ambystoma mex icanum ) i s supreme in te rms o f regeneration. It can regrow its brain, eyes,

heart and legs, and even if all four legs are paralysed it can still regenerate the nerves and ability to move again!

墨西哥鈍口螈 Mexican Axolotl

蚯蚓斷開兩截後可再生為兩條蚯蚓。An earthworm broken into two parts can become two new earthworms.

千奇百趣大自然 Amazing Nature