A “false” silverfish: Ctenolepisma lineata
It’s dark. You are comfortably sitting in your couch or in your chair. Tonight is a relaxing evening. You’re here at binge-watch a series on your favourite streaming platform. While you’re absorbed by what’s happening on your screen, suddenly a silver flash appears in your peripheral field of view. Quickly you turn yourself back in its direction to see… Nothing… Whatever it was, it’s gone. Maybe it was just a reflection of your screen? Maybe you were just falling asleep… Or maybe there was actually something… By the way, you have that strange feeling you’re being watched… Anyway, you forget all this and get back on your stream! Plot elements should not be missed! By the way, it’s time to enhance this session with popcorn! You turn to your bowl laid on the table; bring it closer to you so you can grab some popcorn when all of a sudden you see a silvered legged-tear-shape running fast on the table, making amazing drifts! And that’s when the entomologist inside you says: “A dinosaur”
The insect you just saw belongs to what was once called the order Thysanura, now divided into two orders, the Zygentoma and the Archeognatha (also called Microcoryphia). These are primitive insects without wings, characterized by the presence of three more or less long “tails” at the end of their abdomen: the central one is called epiproct, the other two laterals are called cerci. Zygentoma have cerci about the same length as the epiproct, while Archeognatha have much shorter cerci in respect to the epiproct. They are called primitive because they are located at the base of the insect phylogenetic tree, the graphic representation representing the evolution of insects, thus indicating the degree of parentage between the various groups that can be established (roughly a kind of family tree).
The most famous “Thysanura” is arguably the silverfish, by its real name Lepisma saccharina, of the family Lepismatidae, order Zygentoma. Small digression, I think the term silverfish refers only to Lepisma saccharina, especially for the general public, but others think this vernacular name refers not to a species, but to the whole family. Let’s note the Entomological Society of America’s decision to match the term Silverfish with only the species Lepisma saccharina. Unfortunately, as often with vernacular names, it’s a f*cking MEESSSSS, hence the huge advantage of using only scientific names. End of the little digression. As its name suggests, it is silver in appearance, but a little dull and without patterns. Its fast and its rippling movements along with its silver look evoke a fish, hence its name. In fact, there are lots of species that have this look of legged-silvered-tear with three “tail” behind them. Here, although he’s a little brilliant, he’s not really dull and silvered; he has yellowish patterns running along his body. We’re still in Lepismatidae but it’s another genus, Ctenolepisma. Several species are possible, but it can be seen that the last abdominal segment is clearly triangular, so in France it means it is Ctenolepisma lineata. It is a recycler / cleaner who go in his few years of existence feeding on remains of animals or plants, cellulose that he is able to digest possibly through symbiosis with a certain type of bacteria, synthetic or natural fibers… Like its cousin Lepisma saccharina, it is lucifuge and loves wet places. It is quite good and agile at hiding in the slightest crack. Although it is found preferentially outside, under the bark of trees for example, it can be found indoors. Some species of the genus Ctenolepisma live entirely outside.
Last update: July 27, 2021