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(WA) Before moving on to a new topic, I want to finish up our unit on arachnids by looking at what may seem a very unusual aspect of spider behavior --- a species where the young spiders actually consume the body of their mother.
Unlike most other spiders, this species lays one --- and only one --- clutch of 40 eggs in her lifetime. The young spiders hatch in mid-spring or early summer, inside a nest of eucalyptus1 leaves. Their mother spends the warm summer months bringing home large insects --- often 10 times her weight --- for meal. The catch is always significantly more than her young spiders can eat. So, the mother fattens2 herself up on this extra prey3 and stores the nutrients4 in her extra (unfertilized) eggs. As the weather turns colder, there are fewer insect prey to hunt. That's when the nutrients stored in those extra eggs begin to seep5 into the mother's bloodstream. So, when there are no more insects to feed to the young spiders, they attach themselves to the mother's leg joints6 and draw nourishment7 by sucking the nutrient-rich blood.
After several weeks, the mother is depleted8 of all nutrients and she dies. But then how do the young get nourishment? They start to feed on one another. Now, if you recall our discussion of Darwin, you'll see the evolutionary9 value of this: Only the strongest spiders of the clutch will survive this "cannibalism," and the mother spider will have ensured that her genes10 have an increased chance of survival through future generations.
Unlike most other spiders, this species lays one --- and only one --- clutch of 40 eggs in her lifetime. The young spiders hatch in mid-spring or early summer, inside a nest of eucalyptus1 leaves. Their mother spends the warm summer months bringing home large insects --- often 10 times her weight --- for meal. The catch is always significantly more than her young spiders can eat. So, the mother fattens2 herself up on this extra prey3 and stores the nutrients4 in her extra (unfertilized) eggs. As the weather turns colder, there are fewer insect prey to hunt. That's when the nutrients stored in those extra eggs begin to seep5 into the mother's bloodstream. So, when there are no more insects to feed to the young spiders, they attach themselves to the mother's leg joints6 and draw nourishment7 by sucking the nutrient-rich blood.
After several weeks, the mother is depleted8 of all nutrients and she dies. But then how do the young get nourishment? They start to feed on one another. Now, if you recall our discussion of Darwin, you'll see the evolutionary9 value of this: Only the strongest spiders of the clutch will survive this "cannibalism," and the mother spider will have ensured that her genes10 have an increased chance of survival through future generations.
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1 eucalyptus | |
n.桉树,桉属植物 | |
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2 fattens | |
v.喂肥( fatten的第三人称单数 );养肥(牲畜);使(钱)增多;使(公司)升值 | |
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3 prey | |
n.被掠食者,牺牲者,掠食;v.捕食,掠夺,折磨 | |
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4 nutrients | |
n.(食品或化学品)营养物,营养品( nutrient的名词复数 ) | |
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5 seep | |
v.渗出,渗漏;n.渗漏,小泉,水(油)坑 | |
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6 joints | |
接头( joint的名词复数 ); 关节; 公共场所(尤指价格低廉的饮食和娱乐场所) (非正式); 一块烤肉 (英式英语) | |
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7 nourishment | |
n.食物,营养品;营养情况 | |
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8 depleted | |
adj. 枯竭的, 废弃的 动词deplete的过去式和过去分词 | |
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9 evolutionary | |
adj.进化的;演化的,演变的;[生]进化论的 | |
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10 genes | |
n.基因( gene的名词复数 ) | |
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