Silverfish. What I know about silverfish – ‘offishially’ called Zygentoma, an order of insects – could be written on the back of a beermat. So let’s find out about them together.
Why are they significant? ‘The silverfish’ in Australia is a species of Ctenolepisma but usually misidentified as Lepisma saccharinum which is the dominant species in the northern hemisphere (NB: Wikipedia is muddled on this). Whatever the correct name, the domestic silverfish all do much the same thing. They may be familiar creatures in your house, seen occasionally at the edge of carpets or in bookcases or stored clothes, harmless looking and easily squishable. But their diet is starch and similar polysaccharides – paper, cotton, linen, silk, dried food, all things we value and like to store in cupboards. Not wool – that’s left for carpet beetles.
I’m not in a position to say how to exterminate them, but there are plenty of pest control companies who can help. I just live with them – they are never abundant, and I’ve read that some house spiders feed on them – so they are part of the domestic ecosystem! They don’t carry diseases.
Silverfish are ancient survivors – they have been around since the Devonian, 400 million years ago, well before reptiles, mammals and dinosaurs. They have survived enormous changes in climate and atmosphere, so they should be able to keep going for a while longer, in spite of us. One reason is their ability to survive up to a year without feeding. Another is the ability to regenerate appendages (legs etc) each time they moult, which is often, up to 66 times in a four-year lifespan. So a predator grabbing a leg is no hassle.
There are 70 described species in Australia, which my colleagues in the Australian Museum are adding to each year. The native species are under bark, in ant and termite nests, caves, and deep in leaf litter. Most silverfish are so uniform in appearance that DNA analysis has become the best means of determining species. However, there is one cute genus that’s a little bit different; species of Australiatelura look like small golden slaters and live in ant nests.
Silverfish make ideal laboratory animals for school biology classes, as they are low maintenance. They deserve to be better known.
Further literature: G. Smith, 2017, The Australian silverfish fauna – abundant, diverse, ancient and largely ignored. General and Applied Entomology 45: 9-58; G. Smith, 2020, The European silverfish in Australia. General and Applied Entomology 48: 17-18
