Crab spiders, or the “macrocheira kaempferi,” belong to the arthropod family. Crab spiders are named so because of their size and resemblance to both crabs and spiders.
Google “crab spiders” and you will see mesmerizing images of them. Some suggest that crab spiders are human eaters! They can live for at least one hundred years and weigh more than 20 kg during their lifetime. Crab spiders use camouflage-hunting techniques to trap their prey.
Scientifically, its poisonous bite is not dangerous to humans but they hurt a lot. The females of the species are aggressive hunters rather than the male ones. The females, are also the ones to be aware of when they have eggs. They stand like an unmovable guard until the eggs hatch.
If one bites you, you will feel excruciating pain like a hammer blow on the nail. The cut grows to double its size, the nail turns black, the finger discolors and the pain shifts from the fingers to the hand. The symptoms only subside after a few hours.
However, for other preys, they are quite the passive hunters. They remain at one place waiting for the prey. After they trap the prey, they suck them dry. In addition, they move a lot less; they can keep sitting at one place for weeks and not budge a bit.
Crab spiders have marvelously developed eyesight. It is extremely difficult to spot them instantly with the naked eye because they camouflage. Only when you nudge them do they sway their tentacles like a crab.
There are many genera of crab spiders found all over the world, with the most common being the flower crab spiders (genus misumena).