Scorpions are ancient arachnids, a group of predatory animals that includes spiders, ticks, and mites. Their distinctive appearance, featuring large claws and an arched tail, often leads to confusion about their offensive anatomy. Many people assume scorpions bite with fangs like a spider or snake, but the mechanics of their predatory and defensive actions are quite different. Understanding the structures scorpions use for stinging and feeding clarifies their true biological nature.
The Structures Mistaken for Fangs
Scorpions do not possess true fangs, which are defined as structures near the mouth that inject venom, as seen in spiders and venomous snakes. The confusion stems from the two pairs of appendages located on the cephalothorax, or head region: the large, grasping claws and the much smaller mouthparts.
The large claws are technically known as pedipalps, the second pair of appendages on the scorpion’s body. These robust, pincer-like structures are primarily used for capturing, crushing, and holding prey, as well as for defense and courtship rituals. They are not involved in venom injection. The actual mouthparts, called chelicerae, are located directly in front of the mouth.
The Scorpion’s Venom Delivery System
The scorpion’s weapon for envenomation is located at the end of its segmented tail, known as the metasoma. The metasoma terminates in the bulbous stinging apparatus called the telson. The telson is a modified segment that contains a pair of venom glands, which are the biological factories for producing the toxin.
The sharp, curved barb that delivers the venom is known as the aculeus. This structure acts like a hypodermic needle, with venom ducts running from the glands to small pores near the tip. An intrinsic muscle system contracts to pump the venom through the stinger into a victim or prey.
Scorpions use this venom primarily to quickly incapacitate prey, like insects or small vertebrates, and for self-defense. The potency of the venom varies widely among the over 2,500 described species; only about 25 species possess venom considered life-threatening to humans. Species with smaller, more delicate pedipalps often rely more heavily on their venomous sting to subdue prey, while those with large, powerful claws may use crushing force instead.
How Scorpions Use Their Mouthparts to Eat
Once prey is subdued, the scorpion uses its chelicerae to process the meal. These three-segmented appendages are pincer-like and tear off tiny pieces of the prey. They function like sharp jaws, ripping food into a pre-oral cavity beneath the head.
Scorpions cannot ingest solid food and must digest their meal externally before consumption. They secrete digestive juices from their gut onto the food particles in the pre-oral cavity. These powerful enzymes break down the prey’s tissues, transforming the solid matter into a digestible liquid. The scorpion then uses its muscular pharynx, which acts as a pump, to suck the liquefied meal into its digestive system. Indigestible solid fragments, such as the prey’s exoskeleton, are filtered by specialized hairs in the pre-oral cavity and ejected. This external digestion process is highly efficient, allowing scorpions to survive for months on a single large meal due to their low metabolic rate.