Silverfish

Definition

A small, primitive, wingless insect in the order Zygentoma (formerly Thysanura), characterized by a silvery-gray body, three long tail-like appendages (cerci and median caudal filament), and a fish-like wriggling gait. The common name most properly applies to Lepisma saccharinum, though it is widely applied to various Zygentoma species; the Entomological Society of America restricts the term to L. saccharinum specifically. Silverfish are synanthropic, feeding on carbohydrates such as starches, sugars, paper, and natural textiles, and are important as household pests and indicators of damp environments.

Etymology

From the insect's silvery coloration and the sinuous, fish-like motion of its body.

Example

Silverfish damage to museum collections often appears as irregular holes or notched edges on paper, book bindings, and textile artifacts, with frass and feeding marks concentrated in dark, humid storage areas.

Synonyms

• fishmoth
• Lepisma saccharinum (when used strictly)

Related Terms

• Zygentoma
• Thysanura
• bristletail
• firebrat
• Thermobia domestica
• synanthropic insect
• dermestid
• museum pest

Usage Notes

Usage varies regionally and institutionally: global literature often uses 'silverfish' broadly for any Zygentoma, while North American professional entomology typically reserves it for Lepisma saccharinum. The related firebrat (Thermobia domestica) prefers warmer, drier conditions and is sometimes confused with silverfish. The order name Zygentoma has replaced Thysanura in modern classification.