Spiders exhibit diverse reproductive behaviors, with some species offering no parental care and others displaying more involved strategies to enhance offspring survival. This spectrum of care includes guarding egg sacs or constructing specialized silk nurseries for newly hatched spiderlings. A particularly notable form of parental care involves the mother physically transporting her young, a behavior that significantly impacts the early life stages of these arachnids.
Wolf Spiders: Unique Parental Care
Wolf spiders (family Lycosidae) are distinct for their comprehensive maternal care. These robust, agile hunters have hairy bodies, typically dark brown to black or gray, aiding in camouflage. They possess a unique eye arrangement with eight eyes in three rows, providing excellent vision for hunting. Unlike many other spiders, wolf spiders do not spin webs to catch prey; instead, they actively pursue and pounce on their quarry.
After mating, the female wolf spider constructs a spherical silk egg sac. She attaches this sac to her spinnerets at the rear of her abdomen, carrying it constantly as she moves and hunts. This attachment allows her to protect the developing eggs from potential threats and maintain suitable humidity and temperature conditions. When the eggs are ready to hatch, the female tears open the egg sac to release her numerous spiderlings.
How Spiderlings Are Carried
Once the spiderlings emerge from the egg sac, they instinctively climb onto their mother’s body, primarily her abdomen, and remain there for several days to a few weeks. This mass of offspring can be so dense that it gives the mother a fuzzy or “hairy” appearance, sometimes almost completely obscuring her body with only her eyes visible. A single female wolf spider can carry over 100 spiderlings at once. The spiderlings cling to the mother, and if any fall off, she may pause to allow them to reattach.
Despite this considerable burden, the mother wolf spider maintains her mobility and continues to hunt. The spiderlings do not feed during this initial period while on their mother, relying entirely on her for transport and safety. The mother may even stop near water sources, allowing her spiderlings to briefly dismount for a drink before reattaching.
Benefits of Carrying Spiderlings
This unique parental strategy offers several advantages for wolf spider offspring. Carrying the spiderlings on her back provides them with immediate and constant protection from predators. The mother, being an active hunter and formidable defender, acts as a living shield for her vulnerable young. This direct maternal guarding significantly increases the survival rates of the spiderlings compared to those left dispersed or unguarded.
The ability to transport her young also allows the mother to move them to more favorable environments, such as areas with better resources or safer shelter. This mobile nursery ensures that the spiderlings are not confined to a single location, enhancing their chances of reaching independence. The continuous presence of the mother provides warmth and care until the spiderlings undergo their first molt and are large enough to disperse and begin fending for themselves, typically after about two weeks.