Alabama Water Spiders

Alabama is home to some strange insects such as the two species in the dolomedes genus of spiders. More commonly known as fishing spiders, or water spiders, the six-spotted and dark fishing spiders are both semi-aquatic spiders and can walk on the surface of water. If startled they can actually dive below the surface using oxygen trapped in their leg hairs to remain underwater for up to 45 minutes.

  1. Description

    • The two fishing spider species are both relatively large and grow to be between 2 to 3 inches in length, on average. In both species the females tend to grow the largest. The six-spotted fishing spider is gray to light brown in color with lighter spots on its abdomen. The species is most recognizable from the six black spots on the underside of its abdomen. The dark fishing spider has a mottled gray to dark brown body coloration with distinctive W-shaped markings on its abdomen.

    Habitat and Range

    • As well as both being found in Alabama, the two species are found along the east coast from New England to Florida, and west as far as Texas and the Dakotas. The preferred habitat for both spiders is around bodies of water such as lakes. They can be found living in lakeside vegetation or man-made structures near to the water such as boat docks.

    Hunting and Diet

    • Unlike many spiders that weave webs to catch prey, water spiders use surface waves to pinpoint prey. The spiders detect the waves caused by prey items on or just below the water's surface, just as other spiders use a web's strands. It hones in on the source of the disturbance and dives to catch the prey which can be aquatic insects, tadpoles, larvae or small fish. The spiders have to move quickly to catch food as water, unlike webs, does not hold prey in place.

    Life Cycle

    • The spiders of both species live solitary lives only coming together to mate which can be deadly for the males. If hungry, or misunderstanding the male's intentions, the female spider will kill and eat the male before mating can take place. If mating does take place the female spins a silk sac that can hold more than 1,000 eggs. She carries the sac in her jaws until just before hatching. When hatching is imminent, the female attaches the sac to sheltered vegetation and guards it until the babies hatch. The guarding continues until the newborn spiders are ready to move off on their own, usually after a week.