This order includes the silverfish and firebrats, distinguished by three long posterior filaments. The name Thysanura is from the Greek thysanos for "fringe" and oura for "tail", that refers to the 3 caudal filaments. The common name also refers to the silvery glitter of scales covering their bodies. Their movement resembles that of fish swimming in water. They are less than 1 cm. long, and commonly occur in damp habitats or around books.
The body is flattened and sometimes elongated or oval in shape. Their antennae are flexible and they have small compound eyes that are often absent. The mandibles are short unspecialised. Many species also bear short appendages on their abdomen. The most distinctive feature is the presence of three long, tail-like filaments that extend from The posterior of the abdomen. These are formed from the abdominal cerci. Their habitat is in both moist or dry, habitats both as free-living organisms or as nest inhabitants.
The food includes paste, paper, cereals, starch in clothes, rayon fabrics and dried meats. They may also be found in bathrooms. They do not prefer smooth surfaces. Wild species often are found in caves, and some species are commensals in association with ant colonies, e.g., Trichatelura manni.
The largest family is Lepismatidae, which is widespread with more than 205 species, many of which live in association with humans.
Silverfish have an interesting courtship. The male spins a silken thread between the substrate and a vertical object. A spermatophore is then deposited beneath this thread after which a female is enticed to walk under the thread. When her cerci contact the silk thread, she picks up the spermatophore with her genital opening. Silverfish continue to molt throughout their life. There are several sexually mature instars, unlike more advanced insects. They are relatively slow growing, and they may live for four years or more.
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Sturm, H. 2003. Zygentoma in Resh VH, Cardé RT. (eds.) (2003) Encyclopaedia of Insects. Academic Press. pp. 1203–1205
Torgerson, R. D. Akre 1969. Reproductive Morphology and Behavior of a Thysanuran, Trichatelura manni, Associated with Army Ants, Annals of the Entomological Society of America, 62, pp. 1367-1374
Triplehorn C. A. & Norman F. Johnson, Borror and DeLong's Introduction to the Study of Insects, 7th edition (Thomas Brooks/Cole, 2005), pp. 177–180