英语流利说 第38天

红色表示重点词汇

蓝色表示句子主干

带着问题听讲解

Q1: 请总结一下文中关于“哺乳”和“幼蛛”的表达。

Q2: 蜘蛛和鸽子的哺乳有何不同？

Q3: pigeon 和 dove 有什么区别？

Scientists discover spider species that feeds its young milk

The ability of mothers to produce milk for their babies is commonly considered a unique feature of mammals, but now scientists have discovered a species of spider that also nurses its young.

Spider mothers were observed feeding a milk-like substance to their spiderlings and continuing to look after them almost into adulthood.

Lactation-like feeding is known elsewhere in the animal kingdom—pigeons and flamingos produce something called “crop milk” from a gland in their neck. However, the intensity and duration of maternal care observed in the spider species is considered highly unusual.

The observations focused on a species of jumping spider, normally found in Taiwan, which lives in nests and mimics the appearance of ants. The newly hatched spiderlings were found to be entirely dependent on nutritious spider milk, containing nearly four times the protein of cow’s milk, secreted and fed to them by their mothers.

The scientists observed that the spiderlings first drank from droplets of spider milk left on the surface of the nest and then by directly sucking from the mother’s egg-laying opening.

The spider mothers continued to care for and feed their offspring for nearly 40 days, long after they were able to forage on their own and almost until the point of sexual maturity.

The milk was not critical to the offsprings’ survival, but appeared to boost their overall health and chances of survival as adults.

The findings, by scientists at the Chinese Academy of Sciences in Yunnan, are published in the journal Science.

 

 

 

科学家发现了哺乳蜘蛛

母亲为婴儿分泌乳汁的能力通常被认为是哺乳动物的一个独特特征，但现在科学家们发现，有一种蜘蛛也存在哺乳行为。

科学家观察到蜘蛛妈妈给小蜘蛛喂食一种奶状物质，并继续照顾它们，直到幼蛛几乎成年。

在动物王国的其他地方也有很多类似泌乳喂养的行为——鸽子和火烈鸟就从它们脖子上的腺体中分泌一种叫做“鸽乳”的东西。然而，人们认为，在蜘蛛这一物种身上观察到的母蛛亲代抚育行为的密集程度和持续时间是极不寻常的。

此次观察的对象是一种通常出没在台湾的跳蛛，它们生活在巢穴中，有着近似蚂蚁的外形。新孵化出的幼蛛被发现会完全依赖营养丰富的蜘蛛乳汁存活，其蛋白质含量是牛奶的近四倍，由母蜘蛛分泌并喂食给幼蛛。

科学家们观察到，幼蛛首先吸食巢穴表面残留的乳滴，然后直接从母体的产卵口吮吸乳汁。

母蜘蛛继续照顾、喂养了它们的幼蛛，这一过程长达近 40 天，远超小蜘蛛们能够独立觅食的时间，且它们到那时候几乎已到达了性成熟。

这种乳汁对幼蛛的存活并不是至关重要的，但似乎能提高他们成年后的整体健康水平和存活几率。

美国《科学》周刊发表了中国科学院云南分院科学家们的这一研究成果。