THE ANIMAL FILES

Silverfish

Lepisma saccharinum

Its silver shimmer belongs to an insect, not a fish.

The silverfish is a wingless, night-active insect with a tapering abdomen. Silvery scales and a wriggling run explain its common name, while three long projections extend from the rear of its body.[1]

Follow the evidence ↓
Silverfish
Image: Aiwok · Commons · CC BY-SA 3.0
Wings
Absent[1]
Rear appendages
Two cerci and a central filament[1]
Development
Moulting continues in adulthood[1]

A fish-like outline without fins

The body narrows behind a broader front and moves rapidly in a side-to-side motion. Long antennae project from the head. This combination produces a fish-like impression on land without any connection to aquatic locomotion.[1]

Growing through repeated moults

Newly hatched silverfish are pale and resemble small adults. Their metallic appearance develops as they grow. Unlike insects that stop moulting on reaching adulthood, silverfish can continue replacing the outer covering after maturity.[1]

Food can be hidden in materials

Starches and other carbohydrates occur in adhesives, paper-associated materials and food fragments. Such resources help explain why silverfish can feed in human buildings. They also consume other organic materials, including dead insects and shed skins.[1]

A COMMON MIX-UP

Does the name mean it is a tiny aquatic fish?

No. It is a six-legged insect whose shape and movement inspired the name.[1]

TRY A LITTLE REASONING

Why can a shed skin become part of the food supply?

Reveal the explanation

Silverfish use a range of organic materials and have been recorded eating their own moults. Moulting changes the body and leaves material behind.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Silverfish (fixed revision; adapted and translated)
  2. NCBI Taxonomy — Lepisma saccharinum (identity and classification)

Last fact check:

One discovery leads to another

American cockroachA name can travel farther than an animal’s origins.Periplaneta americana ↗American bird grasshopperThe same grasshopper can grow up in different colours.Schistocerca americana ↗Desert locustThe same species can be solitary or part of a swarm.Schistocerca gregaria ↗