Scorpion Anatomy

All common scorpions are made up of two segments: the cephalothorax and the abdomen.

The cephalothorax is made up of the head, including the carapace, the eyes, chelicerae or the mouth, the pedipalps or the claws, and four pairs of walking legs.

These claws are one of the most significant parts of the scorpion, since they are used to seize prey and defend against predators.

The opisthosoma, or the abdomen, is split into two parts, namely the mesosoma and the metasoma. The mesosoma has seven parts whereas the metasoma has five.

The mesosoma, which is the abdomen’s front half, is made up of six segments. The first are the sexual organs, including a pair of vestigial and modified appendages that form a structure called the genital operculum. The second is the featherlike sensory organ called the pectines. The last four segments contain each pair of lungs. All in all, the mesosoma is shielded with tergites, a chitinous plate on the upper surface, with the sternites on the lower surface.

The other half of the abdomen, which is the metasoma, includes the tail. The tail has six segments, the last of which contains the anus and the stinger. The telson has a vesicle, which in turn has a pair of venom glands and the hypodermic aculeus, or the barb. Some scorpions are born with two tails, which is considered a genetic abnormality.

The cuticle is the tough armor that surrounds the scorpion’s body. It is covered with hairs that work as balancing organs. An ultraviolet light can turn scorpions into a fluorescent green shade.

How Long Is a Scorpion?

Common U.S. scorpion species ranges

in size from half an inch to four inches long, including the tail. A common variety, the common striped bark scorpion, grows up to 6.3 cm long. However, almost all scorpions have the same general appearance.