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用100个屁股遇见海洋蠕虫,每个人都可以生长眼睛和大脑

Ramisyllis Mudaudata的单一活页样的小部分,解剖外部海绵并通过立体显微镜观察。
Ramisyllis Mudaudata的单一活页样的小部分,解剖外部海绵并通过立体显微镜观察。 (图片来源:Guillermo Ponz Segrelles / M。特蕾莎修女Aguado/Christopher J. Glasby)

多少屁股太多了?对于大多数动物而言,除非你是一种带有身体的海洋蠕虫,否则具有一个船体,该船体从单个头部分成数十个不同的方向,并且这些分支中的每一个都以屁股结束。

蠕虫的怪异不会在多个烟头处停止。当蠕虫准备繁殖时,他们的屁股可以长出眼睛和大脑。

此时,您可能有疑问;难以理解的是,科学家也做到了。所以他们在这个许多对接的海洋怪人的分枝体内凝视着,它被命名Ramisyllis multicaudata和澳大利亚达尔文附近的水域住。首次,研究人员已经描述了奇怪的生物的内部解剖学,揭示了蠕虫的内部的内部与他们的外地一样特殊。

(Well, almost.)

有关的:地球上的极端生活:8个奇异的生物

r. multicaudata.是一个分段的蠕虫,或anchelid,在Syllidae家庭。那家族中有一千个描述的物种,但其中只有两个种植巨大,分支机构:r. multicaudata.和深海蠕虫Syllis ramosa

Branching bodies are quite common in plants and菌类但是,在动物的情况下,这种类型的身体计划几乎是闻所未闻的澳大利亚科学院。当生物学家威廉麦金托斯描述时S. Ramosa.1879年,他评论了这种令人惊讶的能力,并指出Annelid在一项新的研究中报道了一个新的研究,4月4日出版形态学杂志

先前的考试r. multicaudata.根据新的研究,它于2012年发现于2006年并于2012年命名,记录了“高位”的肛门开口,“一个每次后端一个”。一旦蠕虫准备好繁殖,那么这些后位会变得更加有趣。科学家们报道,分段单位称为蠕虫的屁股队的结束,不仅产生性器官,澳门金莎网上游戏还生产“一个简单的头脑”。“一旦匍匐茎准备就绪,它就会从身体的其余部分脱离并自由游泳,直到它伴侣和死亡。”

However, the inner workings of these free-swimming stolons — and of the worms' internal anatomy — was almost entirely unknown. The researchers therefore turned to microscopy,X-raycomputed microtomography (micro-CT) scans, tissue staining and chemical analysis to identify the worms' organs and anatomical systems, and to reconstruct them digitally in 3D.

Fragment of the anterior end of an individual living worm, Ramisyllis multicaudata, dissected out of its host sponge. Bifurcation of the gut can be seen where the worm branches. The yellow structure is a differentiation of the digestive tube typical of the Family Syllidae. (Image credit: Guillermo Ponz‐Segrelles/Christopher J. Glasby)

Butt brains

他们发现有一个大脑和神经系统in the stolons, with a dense ring of serotonin-releasing nerve endings positioned just behind each stolon's head. The notion of stolons possessing an autonomous brain was an idea that had been proposed in the 19th century "but had not been confirmed since then," lead study author Guillermo Ponz-Segrelles, a zoologist at the Autonomous University of Madrid, told Live Science in an email.

剩下的r. multicaudata.'s body, blood vessels stretched through all the branches, but the researchers found no structures resembling hearts.循环消化器官划分和分支,无论身体所做的,又鲁棒的“肌肉桥梁” - 在蠕虫中从未见过的肌肉结构,在每个新分支的交界处形成。澳门金莎网上游戏通过分析这些桥梁的形状,科学家们可以告诉哪些机构分支年龄较大,最近形成了更新的身体分支机构。澳门金莎网上游戏

Another unusual discovery was that even though the worms' digestive system seemed to be functional, "their intestines seem to be always empty," Ponz-Segrelles said.

蠕虫Ramisyllis MultiCata的一个样品的几个后端可以被视为朝向主管海绵(Petrosia)表面爬行的白线。 (Image credit: Christopher J. Glasby)

r. multicaudata.花费大部分成年生活拥抱海绵主机,蠕虫的头部埋在海绵内部。科学家的X射线和数字3D模型首次出现了蠕虫的整个分支体也深深嵌入其主机中,蠕虫的分支延伸通过刚毛运河的“一个值得注意的部分”,这些分枝是海绵的一部分的“一个值得注意的部分”内部解剖学。

"Our research solves some of the puzzles that these curious animals have posed ever since the first branched annelid was discovered at the end of the 19th century," said study co-author Maite Aguado, a curator of animal evolution and biodiversity in the Biodiversity Museum of Göttingen in Germany.

"However, there is still a long way to go to fully understand how these fascinating animals live in the wild," Aguadosaid in a statement。"For example, this study has concluded that the intestine of these animals could be functional, yet no trace of food has ever been seen inside them and so it is still a mystery how they can feed their huge branched bodies. Other questions raised in this study are how blood circulation and nerve impulses are affected by the branches of the body," she said.

最初发表于现场科学。澳门金沙网上游戏