Slugs are not exactly glamourous animals. Wordsworth never felt moved to write a poem about a slug. Noah, when drawing up the guest list for his ark, probably “lost” the slugs’ invitation and was slightly annoyed when they turned up anyway. According to a Hollywood legend, the original screenplay for The Lion King went like this:
Mufasa: Everything you see exists together in a delicate balance. As king, you need to understand that balance and respect all the creatures, from the crawling ant to the leaping antelope.
Simba: Including slugs?
Mufasa: Eww, no, not slugs. I hate those things.
But the humble slug has proven itself incredibly valuable. Recently, researchers at Harvard University manufactured a surgical glue from the Dusky Arion slug, a common variety found in the UK and several other European countries. The defensive mucous which the slug secretes has been bioengineered to create a glue that is strong, is less likely to come undone through blunt trauma, and, most crucially, sticks to wet surfaces, which has been a recurring problem with surgical glue. According to the journal Science where the findings were first reported:
“Existing adhesives are cytotoxic, adhere weakly to tissues, or cannot be used in wet environments. We report a bioinspired design for adhesives consisting of two layers: an adhesive surface and a dissipative matrix. The former adheres to the substrate by electrostatic interactions, covalent bonds, and physical interpenetration. The latter amplifies energy dissipation through hysteresis. The two layers synergistically lead to higher adhesion energies on wet surfaces as compared with those of existing adhesives. Adhesion occurs within minutes, independent of blood exposure and compatible with in vivo dynamic movements. This family of adhesives may be useful in many areas of application, including tissue adhesives, wound dressings, and tissue repair.”
In layman’s terms, it’s sticky and it’s good. Yes, those pests that you regard with revulsion as you sprinkle poison pellets around your flowerbed, the scourge of gardeners everywhere, the most maligned of evolution’s inelegant prototypes, may be the holy grail of wound management. In recognition of this, it seems only fitting to attempt to rehabilitate the slug’s reputation. Here are some fascinating slug facts:
Slugs lay 20-100 eggs at a time, and do it multiple times every year. It is possible for a single slug to beget around 90,000 grandchildren. Slugs are hermaphrodites and can self-reproduce.
While they are notorious for laying waste to vegetable patches, the majority of a slug’s diet is decomposing vegetation, making them a vital part of the ecosystem. Slugs consume around forty times their weight in the space of a day.
Some slug species are carnivorous, eating worms, carrion, and even other slugs. Slugs have approximately 27,000 “teeth”, which is more than a shark, although Jaws probably wouldn’t be quite so scary if it were about a slug.
A 21-year-old Australian man contracted the rare rat lungworm parasite, a form of meningitis, after eating two slugs on a dare. In Australia, the wildlife endangers you.
At any one time, 95% of slugs are underground, nibbling on seeds and roots and laying eggs. It is believed that the average British garden contains over 20,000 slugs and snails, with a cubic metre alone housing a population of around 200 slugs.
Many slug species are under threat. In 2008, the Centre for Biological Diversity declared there to be 32 endangered species of snails and slugs in the Pacific Northwest USA alone. Slugs may not be as charismatic as rhinos or tigers, but in many ways they are in fact more important to the ecosystem.
The name “gastropod” literally means stomach foot. A slug is basically a foot that eats stuff.
Slugs have been present in the British Isles since the Ice Age, meaning they have been here longer than humans. There is no data on whether slugs voted for Brexit.
Yes, even the most unassuming of creatures have a part to play (I’m sure there’s a teen drama to be found somewhere in this). The glue has already been used to repair a hole in a pig’s heart, and while it is not yet at the stage of entering wider use, it seems quite likely that this will one day revolutionise both human and animal wound treatment. Not bad work for a slug.
If you’re interested in wound management, you might like our Expertise Series on the subject. Check out the Expertise Series page to find out more.