Six-spotted Fishing Spider, Dock Spider
Dolomedes triton
Pisauridae (Nursery Web Spiders), Order Araneae
Physical Description
The body is robust and elongated, consisting of a distinct cephalothorax and abdomen. It has a velvety texture covered in fine, water-repellent hairs that allow it to walk on water surfaces.
Size Estimate
Body length ranges from 15 to 26 mm for females (males are smaller, around 9 to 13 mm) with an impressive leg span reaching up to 70 to 80 mm.
Coloration & Markings
Base coloration varies from greyish-brown to olive-green, featuring prominent white or light yellow stripes running along the sides of the cephalothorax and abdomen.
Web Type
Does not build a web to catch prey; instead, it is a wandering hunter that utilizes the surface tension of water.
Eye Arrangement
Arranged in two distinct rows of four eyes each, all roughly equal in size, characteristic of the Pisauridae family.
Leg Characteristics
Long, powerful legs held out flat against the surface to detect ripples and vibrations in the water.
Venom & Safety Information
Venom Information
Contains neurotoxic venom used to subdue aquatic prey quickly, but it is not potent or dangerous to humans.
Medical Significance
Harmless to humans. A bite may cause minor localized pain and swelling similar to a mosquito or bee sting, but it is rare and only occurs if the spider is trapped against the skin.
Safety Recommendations
If found in a pool or near living areas, gently guide it into a container using a piece of cardboard to safely relocate it outdoors away from water hazards.
Habitat & Behavior
Habitat & Range
Found near slow-moving streams, ponds, swamps, and swimming pools across North America, often resting on docks or emergent vegetation.
Behavior & Temperament
Skittish and fast-moving, capable of running rapidly across water or diving beneath the surface to escape danger.
Diet & Prey
Feeds on aquatic insects, small fish, tadpoles, and sometimes small amphibians by sensing surface vibrations.
Seasonal Activity
Most active during the warm spring and summer months, overwintering under bark, rocks, or leaf litter near water.
Description
The Six-spotted Fishing Spider is a magnificent semi-aquatic hunter often spotted near bodies of water, including backyard swimming pools. With its impressive leg span and water-walking abilities, it commands attention as an agile predator of the water's surface.
Key Features
Distinctive white or yellowish lateral stripes on the body and long legs adapted for navigating water surfaces.
Similar Species
Wolf spiders (Lycosidae), which often run on dry ground rather than staying closely tied to aquatic margins, and other Dolomedes species.
Life Cycle
Females carry round egg sacs in their jaws until just before hatching, then construct a tent-like nursery web where spiderlings stay until their first molt.
Ecological Importance
Acts as an important natural controller of aquatic insect populations and serves as prey for birds, fish, and amphibians.
Conservation Status
Stable and common throughout its native range, facing no major conservation threats.
Interesting Facts
Can dive underwater and stay submerged for up to thirty minutes to escape predators or hunt small aquatic creatures.
Photography Tips
Use a macro lens from a low angle close to the water surface, preferably on a bright, overcast day to reduce harsh reflections.
Identified: 2026-08-28T21:22:50.321702