Scorpions are predatory arachnids recognized by their grasping pincers and segmented tail ending in a stinger. Unlike most spiders, insects, and other arachnids that lay eggs, scorpions universally give birth to live young. This reproductive strategy sets them apart within the arthropod world. The process involves a period of internal development that can be quite lengthy depending on the species.
How Scorpions Reproduce
Scorpions reproduce through a sexual process beginning with an elaborate courtship ritual known as the “promenade à deux,” or “walk for two.” The male initiates this dance by grasping the female’s pincers (pedipalps) and leading her across the ground. This ritual lasts until the male finds a suitable, stable substrate to deposit his sperm packet.
Once a location is found, the male extrudes a spermatophore, a stalked capsule containing sperm. He maneuvers the female over the spermatophore until her genital opening (the genital opercula) aligns with the packet. This allows the sperm to be transferred internally, fertilizing the eggs. Following fertilization, the female undergoes a long gestation period, which can range from a few months to over a year.
Scorpions exhibit two forms of internal development: ovoviviparity and viviparity. In ovoviviparous species, embryos develop within an internal egg sac, hatching before birth. Viviparous species have embryos that grow in a specialized structure, often feeding through a teat-like connection to the mother. This internal nourishment ensures the young are born fully developed.
The Birth and Appearance of Scorpion Babies
When gestation concludes, the female prepares for birth by raising the front of her body. She forms a small enclosure, often called a “birth basket,” using her front legs and pedipalps. The young, sometimes numbering up to a hundred, exit one by one through the genital opening. They are born in a stage known as the pro-juvenile or first instar.
These newborns, called scorplings, appear pale, soft, and colorless, lacking the hardened exoskeleton of an adult. They quickly shed an embryonic membrane and immediately climb onto their mother’s back. At this stage, they are entirely dependent and cannot forage or sting effectively. They must undergo their first molt to develop the rigid exoskeleton and functional appendages necessary for independent life.
The first molt occurs while the scorplings are still on their mother’s back, usually within 10 to 20 days after birth. This shedding results in a nymph that more closely resembles the adult, including a functional stinger and robust leg structures. Once this transformation is complete, the young are physically ready to face the outside world.
Why Scorpion Babies Ride on Their Mother’s Back
The post-birth ride on the mother’s back is a period of maternal care, which is unusual for an arachnid. The vulnerable scorplings are not equipped to survive alone, so this behavior provides immediate protection from predators. The mother’s body acts as a mobile shield, significantly increasing the survival rate of the young.
The mother’s back also provides a beneficial microclimate, offering a stable environment for temperature regulation and high humidity. This shelter is important for the scorplings to successfully complete their first molt. The young have specialized suckers on their tarsi that help them cling securely to the mother’s carapace.
The ride lasts until the first or second molt, when the scorplings have a fully hardened exoskeleton and are considered second-instar nymphs. Once this physical maturation is complete, the young disperse. They leave the mother’s back to begin hunting and establishing their own territories, marking their transition to independence.