Silverfish

Taxobox
name = "Lepisma saccharina


image_width = 200px
regnum = Animalia
phylum = Arthropoda
classis = Insecta
ordo = Thysanura
familia = Lepismatidae
genus = Lepisma
species = "L. saccharina"
binomial = "Lepisma saccharina"
binomial_authority = Linnaeus, 1758

"Lepisma saccharina" (commonly called the fishmoth, urban silverfish or just the silverfish) is a small, wingless insect typically measuring from a half to one inch (12–25 mm). Its common name derives from the animal's silvery blue colour, combined with the fish-like appearance of its movements, while the scientific name indicates the silverfish's diet of carbohydrates such as sugar or starches. It belongs to the basal insect order Thysanura, and the species is estimated to have existed for over 300 million years, originating in the Paleozoic Era. [ [http://entomology.uark.edu/museum/silfsh.html University of Arkansas: Arthropod Museum Notes 2005] ] Often misidentified as a silverfish is the house centipede, another house-dwelling arthropod that exhibits rapid, fluid movement.

An eyeless species of silverfish, or a close relative, was discovered in January 2006 in caves in Sequoia National Park, California.

Diet

The favorite food of silverfish is any matter that contains starch or polysaccharides, such as dextrin in adhesives. These include glue, book bindings, paper, photos, sugar, hair, and dandruff. Silverfish can also cause damage to books, tapestries, and textiles. Silverfish will commonly graze in and around showers, baths, and sinks on the cellulose present in many shampoos, shaving foams and so on. Apart from these cases, the damage caused by silverfish is negligible and they have no direct effect on human health beyond psychological distress to those who are frightened or disgusted by their appearance. Other substances that may be eaten include cotton, linen, silk and synthetic fibers, and dead insects or even its own exuvia (moulted exoskeleton). During famine, a silverfish may even attack leatherware and synthetic fabrics. In extreme cases, silverfish may live for a year without eating.cite web|url=http://www.ext.vt.edu/departments/entomology/factsheets/silverfi.html|title=Silverfish|accessdate=2008-08-27|last=Day|first=Eric|year=1996|month=August|work=Virginia Cooperative Extension|publisher=Virginia State University] Silverfish can be found anywhere in homes including, but not limited to, garages, closets, underneath beds, couches, electrical appliances such as keyboards and generally preferring dark areas.

Reproduction and growth

The reproduction of silverfish is preceded by a "love dance", involving three phases, which may last over half an hour. In the first phase, the male and female stand face to face, their trembling antennae touching, then repeatedly back off and return to this position. In the second phase the male runs away and the female chases him. In the third phase the male and female stand side by side and head-to-tail, with the male vibrating his tail against the female. [Von H. Sturm (1965) Die Paarung beim Silberfischen, "Lepisma saccharina". In "Zeitschrift fur Tierpsychologie", Band 13, Heft 1.] Finally the male lays a spermatophore, a sperm capsule covered in gossamer, which the female takes into her body via her ovipositor to fertilize the eggs she will lay later on.

Juvenile silverfish are white in color.

Under laboratory conditions, silverfish may go through between 17 and 66 molts, much more than usual for an insect. Silverfish are one of the rare insects that continues to molt after mating. [Sue Hubbell (1993) "Broadsides from the Other Orders," ISBN 0-679-40062-1.]

Predation

Earwigs, house centipedes, and in rare cases spiders are known to be predatory upon silverfish.

References

External links

* [http://www.ext.vt.edu/departments/entomology/factsheets/silverfi.html Silverfish factsheet] at Virginia Tech, Department of Entomology
* [http://www.entomology.cornell.edu/public/IthacaCampus/ExtOutreach/DiagnosticLab/Factsheets/SilverfishFirebrats.html Frequently Asked Questions about Silverfish] at [http://www.entomology.cornell.edu/Extension/DiagnosticLab/ Cornell Cooperative Extension, Insect Diagnostics Laboratory]
* [http://www.mta.ca/dmf/silverfish.htm Magnified pictures of Silverfish]