 This view is now totally obsolete, but the phylogeny of the "insecta" was in its infancy in the late 19th and early 20th century, and the name was firmly established by the time that more sophisticated views were developed.Silverfish are so-called because of the silvery glitter of the scales covering the bodies of the most conspicuous species (family Lepismatidae).Their movement has been described as "fish-like" as if they were swimming.