10% off orders over $99.00 for a limited time!

What are the chelicerae and why do they appear metallic?

What are the chelicerae and why do they appear metallic?

Brandon Hester |

Jumping spiders are known for their incredible vision, agility, and unique hunting techniques. One striking feature that sets them apart from other spiders is their large, prominent fangs, also known as chelicerae. These fangs play a crucial role in capturing and immobilizing their prey.

When observing jumping spiders closely, you may notice a metallic-looking sheen or iridescence on their fangs. This phenomenon is often referred to as "cheliceral armature" or "cheliceral ornamentation." It adds to the overall visual appeal of these fascinating creatures.

The metallic appearance on the fangs is not actually metal but a structural coloration phenomenon caused by the microscopic organization of the spider's chelicerae surface. The fangs are composed of a chitinous exoskeleton, which is a tough and flexible material commonly found in arthropods.

The metallic appearance is a result of light interacting with the complex nanostructures present on the fang's surface. These nanostructures act like prisms, refracting and reflecting light in a way that creates iridescent colors. The exact arrangement of these nanostructures, along with the composition and thickness of the chitinous material, determines the specific colors observed.

The iridescent colors displayed on the fangs of jumping spiders serve several purposes. They can act as a visual signal during courtship rituals, helping to attract potential mates. Some studies suggest that male jumping spiders with more vibrant and iridescent fangs have a higher chance of successfully attracting females.

Additionally, the metallic sheen may also serve as a form of communication or intimidation. When threatened or confronted by rivals, jumping spiders may display their fangs in a defensive manner, potentially using the iridescent colors to startle or deter predators or competitors.

It's important to note that not all jumping spiders exhibit metallic fangs, and the extent and intensity of the iridescence can vary between species. Some jumping spiders may have completely dull or non-reflective fangs. The presence or absence of this characteristic can be influenced by various genetic, environmental, and evolutionary factors.

In summary, the metallic-looking stuff on jumping spiders' fangs is not actual metal but a result of structural coloration caused by the nanostructures on the surface of their chelicerae. This iridescent appearance serves multiple purposes, including attracting mates, communication, and potentially intimidating rivals or predators.