Peristome

Definition

A structure found in certain invertebrates, such as bryozoans and echinoderms, surrounding the mouth but not typically found in arthropods like insects and arachnids.

Etymology

From Greek 'peri-', meaning 'around', and 'stoma', meaning 'mouth'.

Example

The peristome of a sea urchin is integral to the feeding process, surrounding the mouth and aiding in the manipulation of food.

Related Terms

• Mouthparts
• Feeding

Usage Notes

Peristomes are often associated with structures in non-arthropods, their form and function can vary significantly.