Argyroneta Aquatica

The diving bell spider (argyroneta aquatica) is the only known spider species that lives almost entirely underwater, inhabiting freshwater ponds and slow-moving streams across Europe and northern Asia.

It constructs a silk “diving bell,” a dome-shaped web anchored to submerged vegetation, which it fills with air carried down from the surface in bubbles trapped within the fine hairs of its abdomen and legs.

This bubble serves as both an oxygen reservoir and a gill-like system: dissolved oxygen from the surrounding water diffuses into the bell while carbon dioxide diffuses out, allowing the spider to remain submerged for extended periods—sometimes days—without resurfacing.

The spider uses the bell as both a resting chamber and a nursery for egg sacs, emerging only briefly to hunt aquatic insects or crustaceans.

Its physiology is uniquely adapted to this lifestyle, including hydrophobic body hairs that minimize drag and facilitate gas exchange, making argyroneta aquatica a remarkable example of evolutionary convergence between air-breathing arthropods and aquatic respiration systems.