Several bugs and arthropods might be said to resemble crabs in some way due to their morphology. Here are some that have “crab-like” appearances or are often associated with such a description:
Pseudoscorpions
Pseudoscorpions, also known as false scorpions or book scorpions, are tiny arachnids that somewhat resemble scorpions but are much smaller in size. They have a pair of large pincers (chelae) similar to those of scorpions, and a flat, often ovate body. However, unlike true scorpions, pseudoscorpions do not have a long, segmented tail tipped with a venomous stinger.
In terms of resemblance to crabs:
- Their chelae (pincers) might remind one of crab claws.
- Their general body shape, with a broad cephalothorax and abdomen, could be somewhat reminiscent of a crab.
However, their overall size (many are just a few millimeters long) and the absence of a tail mean they won’t be mistaken for crabs upon closer inspection. The resemblance is superficial, but if one were to think of a terrestrial arthropod with pincers, both crabs and pseudoscorpions (as well as true scorpions) might come to mind.
Crab Spiders
(Family: Thomisidae): These spiders get their name from their resemblance to crabs. They have a broad, flat body and legs that extend outward in a crab-like fashion. They also move sideways, much like crabs.
Pillbugs and Sowbugs
(Order: Isopoda)
While these are crustaceans and not true bugs, they are often thought of as bugs because they are terrestrial. Some people think they have a somewhat crab-like appearance because of their segmented bodies and multiple legs.
Crab Lice
(Pthirus pubis)
This is a type of louse that infests human pubic hair (but can also be found in other coarse body hair). It gets its name from its crab-like appearance.
Crabronidae
This is a large family of wasps. Some members of this family dig burrows and have a slightly crab-like appearance due to their robust body and the position of their legs.