Ancient survivors

You may see this as just a common pest responsible for damage to books and fabrics around the home, but this Gray Silverfish, Ctenolepisma longicaudata, belongs to the Order Thysanura, regarded as one of the oldest and most primitive groups of insects. Silverfish have a number of interesting features:

• their eyes are either greatly reduced or absent
• they are wingless – in fact they have never had wings, unlike other wingless insects that evolved from winged ancestors
• they undergo many moults, even as adults
• females can produce numerous offspring throughout their lives, being sexually mature as early as two months old and before being fully grown – some can lay a clutch of eggs between each moult
• they can survive extremely dry periods by absorbing atmospheric moisture – through their anus!
• they can also survive long periods without eating
• they can live for up to four years – not bad for a small insect!

After managing to photograph one of these introduced pesky and very elusive insects we got to wondering about native silverfish and discovered from the Australian Museum blog that they are well represented with about 50 species described and many more yet to be described, but still relatively little is known about them. Researchers keep finding new species and even new genera filling specialised ecological niches in diverse habitats such as caves, cracks in underground rocks and even in ant and termite colonies.

Like cockroaches, these little animals are great survivors and probably well equipped to deal with climate change!