How Do Spiders Lose Legs?

In general, spiders don’t normally drop their legs. However, some creatures do it for survival. This is referred to as an autotomy. Autotomy is a very common antipredator mechanism, and has been observed in many different animal taxa.

Interestingly, spiders are able to regrow lost legs. Usually, these regenerated legs are not as strong as their original counterparts. For example, a silk spinner spider might regenerate its leg by losing it, then molting, and then growing it back. The initial leg will be thinner and weaker than the previous one, but eventually it will grow to its full size.

Spiders have a fairly robust exoskeleton. It is made up of layers of cuticle, a complex structure comprised of proteins. These proteins are arranged in long chains.

A cuticle is very important to a spider, as it keeps it from drying out. Without it, the arachnid would be a dried out husk.

An arachnid’s exoskeleton has three main regions. The ‘head’ is the fused head and middle, and is also the largest, the ‘body’ consists of the abdomen, and the ‘legs’ are the tubular sections.

A spider’s leg is a bit clunky, but it has some very notable qualities. First, it has a bellow-like structure that pushes outward. Second, it contains a fluid called hemolymph, which is similar to blood in vertebrates.

The cuticle has a very big drawback. Not only does it contain several proteins, but it also can’t expand like human bones.