How they are pinching it with their " nippers" !

它们用螯足死命地抓住鱼，打得可凶了！

The only way to know for sure, and even then there are exceptions, is the size of its pincers.

唯一有判断方法就看它螯足大小，过这也有例外。

That's because chelicerates have blood that has a salinity similar to that of sea water.

那螯足动物血液盐度与海水盐度相似。

But species with tiny little pincers can't count on these alone to subdue their prey, so they have a very powerful and often very dangerous venom.

但螯足纤细种类就能仅靠螯足来制服猎物，所以它们毒液毒性很强，有时候相当危险。

A scorpion with thick strong pincers can master its prey without having to waste energy stinging it, so the venom of these species is usually not very toxic.

螯足粗壮蝎子能直接控制猎物，用费力蛰它，所以这些种类蝎子毒性一般很大。