Silverfish

Zygentoma

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Zygentoma

Pronunciation

How to pronounce Zygentoma: //zaɪdʒɛnˈtoʊmə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Lepisma saccharinum 265840101 by Steven Lamonde. Used under a CC BY 4.0 license.

Cf Thermobia domestica metric ruler (crop) by Jscottkelley. Used under a CC BY 3.0 license.

Ctenolepisma lineatum 260336244 by Harukano. Used under a CC0 license.

Ctenolepisma longicaudatum (10.3897-BDJ.9.e61848) Figure 1 by Sammet K, Martin M, Kesküla T, Kurina O (2021) An update to the distribution of invasive Ctenolepisma longicaudatum Escherich in northern Europe, with an overview of other records of Estonian synanthropic bristletails (Insecta: Zygentoma). Biodiversity Data Journal 9: e61848.. Used under a CC BY 4.0 license.

Thermobia domestica 12739641 by Annika Lindqvist. Used under a CC BY 4.0 license.

Ctenolepisma lineatum 261513424 by Sus scrofa. Used under a CC BY 4.0 license.

Summary

Zygentoma, commonly known as silverfish, encompass approximately 550 species characterized by their elongated, flattened bodies and three long caudal filaments. They inhabit humid environments and have a significant role in detritivory, contributing to ecosystem functions.

Physical Characteristics

Zygentoma have dorsiventrally flattened bodies, generally elongated or oval in outline. Their antennae are slender and mobile. They possess three long caudal filaments: two lateral cerci and a medial epiproct. The Lepismatidae have compound eyes, while some families may lack eyes entirely. Styli are present on abdominal segments, varying by family.

Identification Tips

Key identification features include the presence of three long tail-like filaments, the shape and mobility of antennae, and the structure of their eyes (small or absent). Silverfish exhibit a fish-like movement pattern.

Habitat

Silverfish can be found in moist, humid environments or dry conditions, both as free-living organisms and in associations with nests.

Distribution

Approximately 550 known species of Zygentoma worldwide, with specific families distributed as follows: Lepismatidae are cosmopolitan; Nicoletiidae are often found in more localized habitats like caves; Tricholepidiidae are found in northern California.

Diet

In domestic settings, silverfish feed on cereals, paste, paper, starches in clothing, rayon fabrics, and dried meats. In the wild, they primarily consume organic detritus.

Life Cycle

Silverfish are ametabolous insects, continuing to moult throughout their lives with several instars. They live several years, with a lifespan ranging from four to eight years.

Reproduction

Reproduction involves a courtship ritual where males spin a silken thread and deposit a sperm packet. The female then picks up the sperm with her genital opening. Multiple instars are involved until reaching sexual maturity.

Conservation Status

No current species are formally considered at conservation risk, though some troglobite species face high extinction risks due to their limited habitats.

Ecosystem Role

Zygentoma play a role in decomposing organic matter as they feed on detritus, contributing to nutrient cycling in their ecosystems.

Economic Impact

Some species are considered pests in homes due to their consumption of stored food and materials.

Evolution

Zygentoma diverged from other insects during the Carboniferous or possibly Devonian periods, with the oldest known fossils dating to the Early Cretaceous. They were previously classified under the paraphyletic order Thysanura.

Similar Taxa

Archaeognatha

Misconceptions

Previously regarded as a suborder of the now paraphyletic Thysanura; the name Thysanura has mostly fallen out of use.