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轮虫:迷人、奇异、常被忽视

Rotifers: Charmingly Bizarre & Often Ignored

《微观旅途》
What is this thing?
这是什么玩意儿?
In fairness,
老实说
when the first microscopes were turned on samples of muddy water,
当第一批显微镜用于观察浑水样本时
that was a common question.
那是一个常见的问题
And the discoverers of that time
那个时代的发现者们
were seeing new things every day that puzzled and baffled them.
每天都能看到让他们费解和困惑的新事物
But you would think that, by now, we’d have a pretty good idea.
但是你会认为 如今 我们已经非常了解它了
And yes, this is a rotifer…
说的没错 这是轮虫
but…what is it?
但是……它到底是啥?
There are around 2,000 species of rotifers distributed in watery habitats around the world.
大约有2000种轮虫栖息在世界各地的水域
And so it’s no surprise that they’ve come up on our channel quite frequently.
所以它们经常出现在我们的节目中也就不足为奇了
Unfortunately, their situations on here are usually quite dire.
不幸的是 它们在这儿的处境通常是相当可怕的
They’ve been captured.
它们被捕获
They’ve been swallowed alive.
它们被生吞
Sometimes their body fluids are getting sucked out of them.
有时它们的体液会被吸食出来
You may even remember
你可能还记得
the one rotifer trying to lay its egg as it was slowly being eaten by a heliozoan.
有一个轮虫在被太阳虫慢慢吃掉的时候还试图产卵
So we need to cut the poor little rotifer some slack,
所以我们必须放过轮虫这个可怜的小东西
maybe even make a case for them.
甚至可能要为它们的存在给出些理由
Even if, or maybe because,
虽然 或许也是因为
they seem to have a hard time doing that on their own.
靠它们自己的力量似乎很难做到这一点
Even if we, even now, don’t know precisely
虽然我们至今仍不能确切知晓
what they even are.
它们到底是什么
Rotifers are definitely an animal.
轮虫无疑是一种动物
And they are a type of invertebrate,
它们是无脊椎动物的一种
but beyond that,
但除此之外
here we are in 2019 and, like,
尽管已经2019年了
we just really don’t know.
我们是真的不了解它们
They’re just really…different from other animals,
它们真的……有别于其他动物
though we think they might be related to arrow worms,
不过我们认为它们可能与箭虫有亲缘关系
a tiny animal that is a major component of marine plankton,
箭虫是构成海洋浮游生物主要部分的微小动物
that’s something we first uncovered literally last year.
那是我们去年刚明确发现的物种
It’s been challenging to map out the evolution and relationships of the Rotifera phylum
绘制轮虫门的进化和谱系图是件颇有挑战的事
because despite their apparent propensity for dying,
因为尽管它们很容易死亡
their microscopic, soft bodies make for poor fossils.
但它们微小柔软的身体很难形成化石
We homo sapiens have only found one single rotifer fossil from outside of the Holocene,
我们智人仅仅发现了一例全新世以外的轮虫化石
which is our current geological epoch.
全新世是指我们现在所处的地质时代
We have one sample of a rotifer…
我们这一个轮虫的标本…
fossilized in Amber from around 35 million years ago, during the Eocene,
大约是3500万年前始新世的琥珀化石
and it looks weirdly identical to rotifers that still exist today.
它看起来和现今存在的轮虫惊人地相似
The vast bulk of the Rotifera phylum, make their home in fresh water,
轮虫门的绝大部分都生活在淡水中
and they can be found around the world,
在世界各地都能找到它们的踪迹
from small puddles, to sewage ponds, to crisp, Alpine lakes.
从小水坑 污水塘 到清澈的高山湖泊
They may be microscopic, their bodies typically ranging from 100 to 500 microns long,
它们或许很小 体长一般在100到500微米之间
but their tiny bodies contain even tinier organs:
但它们微小的身体内包含着更小的器官:
from a simple brain, a small stomach a kind of jaw, a nervous system,
有简单的大脑 小小的胃 类似下颚的器官 神经系统
all compartmentalized in various regions of its body.
所有这些器官分布于身体的不同区域
Rotifers come in many different shapes,
轮虫有许多不同的形状
but you can generally break their bodies down into four regions.
但你通常可以把它们的身体分成四个区域
You’ve got the head, the neck, the body, and the foot.
头部 颈部 身体和脚
At the top of the rotifer’s head is the corona,
在轮虫头部的顶端有一个冠
a crown made up of cilia whose movement resembles a turning wheel
它是由纤毛构成的冠 其运动类似转动的轮子
and that is what gives the organism its name:
这就是这种生物名字的由来
in Latin, “rotifer” translates to “wheel-bearer.”
在拉丁语中 “rotifer”的意思是“带有轮子”
The corona helps the rotifer eat,
冠帮助轮虫进食
the beating of the cilia creating a vortex
纤毛的跳动产生涡流
that draws food, like micro algae, into the mouth.
把诸如微藻之类的食物吸入口中
Then the rotifer uses its jaw, called the trophi,
然后 轮虫用它的颚部 也就是口器
to grind down the food.
来磨碎食物
The hardness of the trophi makes it
口器的硬度使它成为
one of the few parts of rotifers that we can find fossils of,
轮虫中极少数我们能找到化石的部分之一
and along with the corona, it is one of the unifying characteristics of rotifers.
和冠一起 它们构成了轮虫的统一特征
Some rotifers reproduce strictly through parthenogenesis,
有些轮虫严格地通过单性生殖进行繁殖
a form of asexual reproduction,
那是无性生殖的一种形式
while others use both asexual and sexual reproduction.
而其他的轮虫同时使用无性和有性生殖
Either way, rotifers are eutelic,
无论哪种方式 轮虫都是恒定细胞数的
which means that from the moment they are born,
这意味着自它们出生的那一刻起
they will have a fixed number of cells in their bodies for the rest of their life.
它们的身体里就是固定数量的细胞 终身不变
For most rotifers, that number is around 1000 cells.
对于大多数轮虫 这个数字大约是1000个细胞
And for the rotifer to grow,
而轮虫为了生长
the cells themselves—which cannot divide—have to get bigger.
由于细胞本身不能分裂 它们必须变大
About a quarter of the cells in a rotifer’s body are dedicated to its nervous system,
轮虫体内约四分之一的细胞贡献给了神经系统
which lets the rotifer process its surroundings and respond accordingly.
它使轮虫能处理周围环境并做出相应的反应
As you may have noticed,
你可能已经注意到
a lot of rotifer species are quite stretchy,
许多轮虫物种是相当有弹性的
extending and contracting as the organism navigates the world.
在航游世界时它们会伸展和蜷缩
At the end of the rotifer’s body, where the foot lies,
在轮虫身体的末端 也就是脚所在之处
you might find glands that secrete a sort of glue
你可能会发现一些分泌胶状物的腺体
that the rotifer can use to attach itself to a surface.
轮虫可以利用它把自己粘在某个表面上
Now, some rotifers form colonies,
有些轮虫会形成群体
which can be as small as two members,
它可以小到只有两个成员
to some much larger colonies that have more than 1,000.
也有一些大到超过1000个成员的群体
These rotifer gatherings can form through different recruitment methods.
这些轮虫群体可以通过不同的方式聚集形成
Sometimes a colony is already established,
有时一个群体已经建立
and a young rotifer comes by and joins in.
然后一个幼年轮虫正好路过并加入进来
Other colonies are constantly developing and expanding as young rotifers are born into them,
其他群体靠幼年轮虫的出生不断发展和壮大
getting smaller only as the colony dies or breaks up.
只有在死亡或分裂时群体才会变小
And sometimes, a bunch of young rotifers decide to just trek out
有时 一群幼年轮虫决定迁出
and establish their own colony together.
一起建立自己的群体
How do they decide to do that?
它们是如何做出这个决定的?
I dunno.
我不知道
They’re mysterious.
它们是神秘的
For all these different ways they start,
无论哪种聚集方式
rotifers inside a colony don’t seem to share resources,
一个群体中的轮虫似乎并不共享资源
so it’s not quite clear what the colony’s purpose is.
所以不太清楚这个群体的目的是什么
Maybe it helps protect them from predators.
也许这能保护它们免受捕食者的攻击
Or maybe it’s….something else…
或许是……别的理由……
remember…mysterious.
还记得吧……神秘
While rotifers can live in the thin films of water found in more earthly environments,
虽然轮虫可以生活在很多土壤环境的水膜中
their habitats can change.
它们的栖息地会改变
Moss, lichen, or soil,
苔藓 地衣或土壤
where rotifers may take up residence because of the dampness,
因为潮湿 所以轮虫可能会在这些地方栖息
are still subject to the daily and seasonal water cycles,
这些栖息地仍然受到日常和季节水循环的影响
and as evaporation dries out their surroundings,
当蒸发使它们周围的环境变干时
many rotifers protect themselves by entering a sort of resting state called anhydrobiosis.
许多轮虫就会进入一种脱水的休眠状态来保护自己
We don’t have an image of this to show you,
我们没有脱水的图像给你看
but imagine
但是想象一下
this rotifer shedding water from its body
这个轮虫从它体内排出水
until it’s about 30-40% of its original weight
直到体重大约为原先的30-40%
and compacted into a little ball,
然后它缩成一个小球
appearing from the outside like nothing more than a tiny grain of silt.
从表面看来就像一粒小小的泥沙
But when water comes back to the rotifer,
一旦水重回轮虫体内
it will switch out of this state and back to an active one,
它就会终止这种状态 恢复到活跃状态
waking up without having aged
醒来时还不会增加年龄
like a microscopic Sleeping Beauty.
宛若显微界的睡美人
Even though they are microscopic
尽管轮虫是微小的
and often ignored by us macro-animals,
经常被我们这些大型动物忽视
and apparently often bullied and consumed by their single-celled neighbors,
显然还经常被它们的单细胞邻居欺负和捕食
rotifers are charmingly bizarre animals.
但轮虫是迷人奇异的动物
They are everywhere,
它们无处不在
minding their own business,
忙着自己的事
living their own lives,
过着自己的生活
and turning themselves into inactive little balls when life gets tough,
当生活变得艰难时就将自己变成不活跃的小球
which makes them, you know, not unlike us sometimes.
这使得它们 你懂的 有时候和我们也没什么两样
So let’s end with a tribute to the rotifer,
最后让我们向轮虫致以敬意
giving it the dignity of words
以这段赋予它尊严的话来结尾
spoken to the Royal Society in the 18th century
轮虫观察者贝克先生
by rotifer-observer, Mr. Baker:
于18世纪对英国皇家学会所说的:
“I call it a Water Animal,
“我叫它水生动物
because its appearance as a living creature is only in that Element.
因为它看上去只是生活在水中的生物
I give it also for Distinction Sake the Name of Wheeler, Wheel Insect, or Animal;”
为了它的名誉 我也称之为轮虫 轮状昆虫或动物 ”
Wheel away little friend,
滚滚向前吧小伙伴
whatever your lineage, however you came to exist.
不管你来自何处 你毕竟来到了这个世界
Wheel away.
滚滚向前
Thank you for coming on this journey with us as we explore the unseen world that surrounds us.
感谢你与我们一起踏上这段探索周围未知世界的旅程
Thank you, especially, to all of our patrons.
特别感谢我们的赞助者
You can find us at patreon.com/journeytomicro
你可以在这里找到我们patreon.com/journeytomicro
And if you want to see more from our Master of Microscopes, James
如果你想看更多《显微镜大师詹姆斯》的节目
check out Jam and Germs on Instagram.
请在Instagram关注Jam and Germs

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视频概述

鲜为人知的轮虫 迷人 奇异 让我们一起去探索

听录译者

收集自网络

翻译译者

zbz

审核员

审核员XY

视频来源

https://www.youtube.com/watch?v=U3PLUeD_JAg

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