1 1 / 16 科教科普类 1、 Australia leads the world in its number of resident poisonous spiders as well as the strength of their toxicity(毒性). However,of almost 9,800 species most are perfectly harmless and interesting. Spider diversity is broad and many fascinating species occur here that range from the large to the tiny and hardly noticed, and from the dullest black to the strangely shaped. Spiders can be roughly classified according to the strategies(策略) they use for feeding. Spiders which appeared earlier in the evolutionary scale feed by waiting in a cave for food to come along before grabbing it. Following them were spiders which actively wandered looking for food and which caught it by chasing it down. The evolution of flying insects makes spiders evolve new ways of catching food which couldn’t be chased and so the earliest air web weavers arose. Most spiders feed on insects and other arthropods but the Whistling Spider feeds on frogs and small birds. The Golden Orb Spider also feeds on small birds. A spider periodically sheds(蜕皮;脱落) its skin so that it can grow. Immature stages are called moults. Each species has a particular number of moults that it will go through before reaching its final adult stage. Usually, once male spiders have mated, they die shortly after. But, even in death, Redback males often serve a purpose. The already pregnant Redback females always kill their lover and, in most cases, also eat them. This provides them with a small reproductive advantage. Allowing spiders to take up places around houses can be beneficial in that they catch other annoying insects such as mosquitoes and flies. Rest assured that while you might see some large spiders, and pe...
