Six-Spotted Fishing Spider

Genus Dolomedes — the fishing spiders, family Pisauridae — contains about 100 species worldwide. The species' common name reflects its remarkable hunting behavior: fishing spiders sit at the edge of ponds and slow streams with the front legs touching the water surface, detecting vibrations from struggling insects, tadpoles, and small fish through the meniscus. When prey is detected, the spider dashes across the water surface (using surface tension and hydrophobic leg hairs, the same mechanism as water striders) and lunges. For underwater prey, the spider dives — pulling a thin film of air with her, captured by hydrophobic body hairs, that wraps the spider in a silvery 'air bubble' for the duration of the dive. She can stay submerged for over 30 minutes. Some Dolomedes species are documented to catch fish up to 5 times their body length, including small minnows, tadpoles, and aquatic insects. The species are also among the largest spiders in North America by leg span: D. tenebrosus reaches 90 mm leg span. Fishing spiders are non-aggressive and harmless to humans, despite size and dramatic appearance.