Colulus

Definition

A small, often vestigial structure found on the underside of the abdomen in some spiders, located near the spinnerets and thought to have once been part of a more developed appendage.

Etymology

From Latin 'colulus', a diminutive form of 'colus', meaning 'spool' or 'spindle', referencing its position near the spinnerets.

Example

In some primitive spiders, the colulus is more pronounced and can be seen as a small, knob-like structure between the spinnerets.

Related Terms

• Spinnerets
• Spiders
• Abdomen
• Vestigial

Usage Notes

The function of the colulus is not well understood and it is considered a vestigial structure in most modern spiders.