Numbers
5 species in North America listed at
nearctica.comSize
body length about 12-19 mm (or 1/2 to 3/4 inch)
Identification
Four-lined Silverfish (formerly Ctenolepisma quadriseriata, now synonymized with C. lineata) has 4 dark lines down its back
Gray [or Giant] Siverfish (which includes the former Ctenolepisma urbana, now synomymized with C. longicaudata) is uniformly gray
these species grow up to 19 mm long - significantly larger than the Common Silverfish and Firebrat (see See Also section below)
See Also
Common Silverfish (
Lepisma saccharina) is smaller (10-12 mm) and has silvery scales but no markings
Firebrat (
Thermobia domestica) is yellowish with dark brown bands and mottled spots on the dorsal surface, and is smaller (about 8 mm) and more stout-bodied (its abdomen is relatively broad-tipped and often shorter than the thorax, giving an overall "chunky" appearance)
may also be confused with
Bristletails (order Microcoryphia), which have large eyes that meet in the middle, a cylindrical body, an arched thorax, mandibles that articulate at only one point, are not normally found indoors, and have the ability to jump
Internet References
live adult image of
C. longicaudata plus other info (Iziko Museums of Cape Town, South Africa)
live adult image of
C. lineata (Kansas State University)
drawings of 2 species; PDF doc with comparison drawings of Common Silverfish and Firebrat, and brief account of each species (Richard Houseman, U. of Missouri)
