The diving bell spider, Argyroneta aquatica, is the only known spider species that lives almost entirely underwater. This fascinating creature has developed specialized behaviors and adaptations that allow it to thrive in an environment where most spiders cannot survive. Its ability to construct and maintain an underwater dwelling is central to its survival and sets it apart in the arachnid world.
Their Freshwater Habitat
Diving bell spiders inhabit various freshwater environments, preferring clean water bodies with minimal current. They are found in ponds, marshes, ditches, and slow-moving streams. Their habitat requires dense aquatic vegetation, such as pondweed or milfoil. These submerged plants provide anchors for the spiders to construct their intricate silk dwellings and offer concealment from potential threats. While they can be found in various depths, they generally prefer shallower areas where vegetation is abundant.
Constructing the Underwater Dwelling
The diving bell spider creates an underwater “diving bell” or air bubble, which serves as its primary dwelling. The spider begins by spinning a silk dome, which it attaches to submerged aquatic plants. To inflate this dome, the spider repeatedly travels to the water’s surface, where it captures air bubbles using its hind legs and the dense, water-repellent hairs on its abdomen. It then carries these bubbles down and releases them into the silk structure, gradually expanding its underwater home.
This air-filled bell functions as a personal underwater breathing apparatus, allowing the spider to remain submerged for extended periods. It serves as a safe space for various activities, including eating prey, molting, mating, and raising young. The silk of the bell is waterproof but permits gas exchange with the surrounding water, effectively acting as a physical gill. Oxygen diffuses into the bell from the water, while carbon dioxide produced by the spider diffuses out, maintaining a breathable atmosphere within the dwelling.
Geographical Range
The diving bell spider is widely distributed across parts of Europe and Asia. Its range extends throughout much of mainland Europe, including the British Isles and central to northern regions. From Europe, its distribution reaches into parts of Siberia and extends as far south as Iran and across to East Asia, including Japan and Korea.