How Do Spiders Grow Their Legs Back?
WouterSpiders have eight legs, but can they regrow a missing one? Depending on the species, it can take months.
Legs are a vital part of a spider’s ability to move and construct a web. Aside from the obvious need for legs, they are essential for predatory function. After a web capture, spiders use their limbs to control the prey.
Although adult spiders can’t regenerate legs, juveniles can. In the past, scientists believed that a spider’s regenerative capabilities put it at a disadvantage. However, recent studies have shown that in some cases, regeneration can be beneficial.
Spiders can regrow their lost legs during molting, a process that takes place periodically. The newly grown leg appears smaller than the rest, but will grow larger over time.
As spiders molt, they peel off their old exoskeleton. Their new exoskeleton is not hardened, but it does stretch. This process involves chemical changes that start when the old skin is shed.
The new skeleton is wrinkled like an egg carton. It contains fluid, called hemolymph, which is similar to blood.
The most important thing to note about the new leg is that it is not as effective as the original. Since it is a replacement, the spider can no longer perform all of the functions it had with the leg that was removed.
Aside from regrowable legs, the regenerated spider also uses adapted sensory organs for positioning. While the spider’s body does not have an internal skeleton, it does have an abdomen and seven joints for each leg.
