Imagine a spider as big as your hand, gliding effortlessly over the water’s surface, ready to strike at unsuspecting prey. No, this isn’t a scene from a horror movie—it’s the marsh-dwelling Dolomedes spider (Dolomedes plantarius), an arachnid once on the brink of extinction, now making an astonishing comeback in Europe, including France.
From near Extinction to Resurgence
Fifteen years ago, this semi-aquatic predator faced a dire situation. Widespread wetland destruction due to urbanization and agricultural expansion had devastated its natural habitat, dramatically shrinking its numbers. This elusive but formidable hunter, recognizable by its chocolate-brown body and distinctive cream-colored stripes, was rapidly disappearing.
A turning point came with an ambitious conservation effort led by the Chester Zoo in the UK. Scientists devised an unprecedented strategy: they bred thousands of young Dolomedes spiders in captivity, painstakingly feeding them tiny flies until they reached a size that ensured survival in the wild. These carefully nurtured spiders were then released into restored wetland habitats, a move that has proven to be immensely successful.
A Booming Population in the UK
Thanks to these efforts, the Dolomedes spider is thriving. The Royal Society for the Protection of Birds (RSPB) has recorded over 10,000 breeding females in the UK—an incredible recovery for a species that was once critically endangered in the region.
These water-walking hunters have quickly reestablished themselves as top predators of their ecosystem, helping to regulate populations of insects, tadpoles, and even small fish. Their success highlights the importance of wetland conservation in supporting biodiversity.
How France Is Witnessing the Return of the Dolomedes Spider
In France, the Dolomedes spider remains rare but is making a steady return. It was rediscovered in 2014 in the Nord-Pas-de-Calais region, a significant finding that signaled the possibility of a larger, previously unnoticed population.
A 2016 study confirmed its presence in 22 French departments, with notable sightings in Picardy and Normandy. While the species is not yet as widespread as in the UK, conservationists believe that with similar habitat restoration efforts, its numbers could grow significantly.
However, unlike many invasive or rapidly spreading species, the Dolomedes spider remains highly dependent on specific wetland environments. This means its survival is closely linked to continued conservation efforts.
Why This Giant Spider Is Good for the Ecosystem
Far from being just a fear-inducing curiosity, this spider plays a crucial role in maintaining ecological balance. With the ability to walk on water and ambush prey with lightning speed, the Dolomedes spider acts as a natural regulator of aquatic insect populations. By keeping insect numbers in check, it helps prevent potential ecological imbalances in wetlands.
Additionally, as a top predator in its niche, it contributes to a healthy and diverse wetland ecosystem, which in turn benefits a wide range of species, from amphibians to birds.
No Need to Panic—These Spiders Don’t Invade Homes
For those already feeling a shiver down their spine, here’s some good news: you won’t find these giants lurking in your house. Unlike some other large spider species, the Dolomedes spider is strictly a wetland dweller, preferring marshes, ponds, and slow-moving rivers over human homes.
This means that while sightings may become more frequent in natural areas, they pose no risk of invading urban environments. Their growing population is a sign of ecological recovery, not a reason for alarm.
kill em all
In which country do you live, Ted? Is there any chance you’ll get bitten by one of these guys?
Yeah If These Giant Spider’s Grow To, Too High Of A Number To Where There’s Just As Many Of Them As There Is Of Us Or Out Number Us, They Could Actually Kill Us Off Possibly If There’s Not Enough Food For Them To Survive!! Think About It! It Might Have Been Not Such A Good Idea After All, Because Of The Main Fact That They Were Already Going Extinct, & Maybe We Should Have Let Them! & Let Nature Take It’s Course, The Earth & Life Would Have To Adapt Like It Always Has, & Nature Is Smarter Than We Are! & Perhaps We Should Have Listened To Mother Nature & Let Her Ensure Our Own Survival. 🌄✝️🕊️
Doesnt matter. When the Wuzzies take over and turn all of Europe into a caliphate, all your efforts will have been in vain, including these spiders.
If anyone gets bit you know who to Sue, Chester zoo. They might not be venomous but I bet a bite from one of those big boys will hurt.
When species get near extinction we should not artificially play with the balance of the planet. They should be allowed to go extinct. Extinctions have been happening for millions of years. They often happen because some other species outcompetes and pushes aside another species. Humans are on earth species they are part of nature and if our activities, or the activities of any other kind unrelated to human beings, cause a species to go extinct, it should go extinct.