This Six-spotted Fishing Spider is one of eight species of fishing spiders in the Dolomedes genus found in the US and Canada. It is greenish brown with distinct white lines and spots. Fishing spiders use the water much like a web to sense insects struggling in the surface film. They will rest on something floating or sticking out of the water, but keep their front two to three pairs of legs on the surface. Ripples caused by potential prey send out vibrations and trigger their predatory response–an agile rowing gait and pounce. They can also dive into the water, either to escape predation, or to prey on submergent animals like small fish or tadpoles. Waterproof hairs around the spider’s abdomen create an air bubble, allowing it to breathe underwater for as long as 30 minutes.

Size: Body length of up to ½ inch for males and ¾ inch for females (not including legs)

Photo by: Rose Marchak on 10/22/21 near Missoula, MT