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By Mirsha Lopez
Geographic Range
Silverfish are found commonly as human commensals worldwide. They are thought to be endemic to the Palearctic.
Biogeographic Regions:
nearctic 
(introduced ); palearctic (introduced , native ); oriental (introduced ); ethiopian (introduced ); neotropical (introduced ); australian (introduced ).
Other Geographic Terms:
cosmopolitan .
Habitat
Natural habitat is hidden in leaf litter, under rocks and logs, and in other natural crevices. When silverfish live indoors, they are most commonly found behind furniture, in books, near sinks or in basements. They prefer temperatures that are 70 to 80 degrees. ("The Bug Clinic", 2000; Sanders and P., 1999)
These animals are found in the following types of habitat:
temperate ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; forest ; rainforest ; scrub forest .
Other:
urban ; suburban ; agricultural .
Physical Description
(0.31 to 0.75 in)
Silverfish are wingless insects that have a carrot-shaped, flat body with silver and grey scales. They are 0.8 - 1.9 cm long. They also have three tail-like appendages and two antennae on their head. Each of the tail-like appendages are almost as long their body. Two point to the sides, while the other one is in the middle, pointing backwards. (Caron and M., 1997; Houge and L., 1993; McGavin and C., 2000)
Some key physical features:
ectothermic ; heterothermic ; bilateral symmetry .
Reproduction
When silverfish mate, the male silverfish puts his sperm on a silk thread on the ground and then the female silverfish picks it up. The fertilized eggs are then laid in cracks and crevices. At a temperature of 22 - 27 degrees C, female silverfish can lay approximately 100 eggs in their lifetime. They lay one to three eggs at a time in small groups and may lay several eggs over a period of weeks. The eggs hatch in three to six weeks; the length of time depends on the temperature. Rate of growth also depends on temperature. Females do not have a certain season when they lay their eggs. They usually lay eggs in secluded places like behind books or closet shelves. After hatching, all the life stages are similar in appearance, except for their size. (Caron 1997, Washington State University 1997, Sanders 1999)
Behavior
Silverfish are active at night and hide during the day. They make quick movements and stop at short intervals then move on again. They avoid direct sunlight. If a silverfish is hiding under an object that gets moved, the insect moves rapidly to hide in another place where there is no sunlight (Sanders 1999).
Key behaviors:
nocturnal .
Food Habits
Common silverfish prefer to eat materials that come from plants because of the carbohydrates and protein. They eat foods such as glue, wallpaper paste, bookbindings, paper, photographs, starch in clothing, cotton, linen, and rayon fabric. They also eat damp textiles and organic material. Although they prefer organic material, they also eat non-organic material. This species also likes dried foods and human foods such as sugar, flour, and breakfast cereal. (The Bug Clinic 2000, Sanders 1999).
Economic Importance for Humans: Negative
Silverfish are generally considered nuisance pests. They have no effect on human health. They usually do relatively little damage, but will feed on paper, book bindings, wallpaper, rayon drapes, starched cotton, linen, and silk (Washington State University 1997).
Economic Importance for Humans: Positive
unknown
Conservation Status
IUCN Red List: [link]:
Not Evaluated.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Lepisma saccharina is considered a pest by many and there are many insecticide treatments to get rid of them (The Bug Clinic 2000, Caron 1997).
Other Comments
Silverfish are primitive insects that were on earth before the cockroaches (Bochnak 1999).
Contributors
Mirsha Lopez (author), University of California-Irvine.
Rudi Berkelhamer (editor), University of California at Irvine.
