Every year, a group of international arachnological associations reveal the European spider of the year. This year's winner of the esteemed title is a spider that has just six eyes instead of eight and is famed for the way it catches its prey.
The snake-back spider (Segestria senoculata) has been crowned 'European spider of the year 2025', the Belgian Arachnological Association (Arabel) confirmed. They live across Europe, including Belgium, where three species of the Segestria genus can be found. The arachnids usually live in forests and woodpiles, but also in parks, gardens and on walls.
"This species is the first representative of the little-known family of six-eyed spiders. It has some unusual characteristics, from the number of eyes and its hunting technique to a leg position that is unique among spiders," Arabel experts said.
The aim of this title is not only to raise awareness of a lesser-known spider, but also to enable scientists to collect more data about its current distribution.
What makes the spider special?
Its English name refers to the spider's row of dark-coloured patches on the elongated abdomen, said to resemble the markings on some poisonous snakes like a viper. Its Dutch name, Boomzesoog (literally translated as 'Tree Six Eye'), refers to the fact that the creature has just six eyes instead of eight, unlike most spiders.
Image of the three eyes. Credit: Ludwig Jansen
The eyes are arranged in three groups of two and form an 'H' when viewed from above.
The creature also has a spectacular hunting technique. It spins its webs in the shape of a narrow, mesh-like tube in cracks and crevices (under tree bark, between stones, etc.)
"The threads are not adhesive, but they do transmit vibrations to the web's inhabitants. This means that when an insect treads over the threads, the spider is alerted and pulls its prey into the narrow tube with its venomous fangs. Insects with stingers or pincers have difficulty using their 'defence weapons' or are unable to use them at all. The silken tube is too narrow for them to manoeuvre their weapons."
Credit: Eckhart Derschmidt
Finally, the position of the legs is also characteristic of all six-eyed spiders: the front three pairs of legs are directed forward, and the back pair of legs backwards. This makes them unique among spiders.
Males (6-9 mm) are generally slightly smaller than females (7-10 mm). They are mainly nocturnal, so the chances of spotting one during a walk are relatively small. However, anyone who does come across one is asked to register the sighting via the ObsIdentify app.
