Pisauridae

Pisauridae can be distinguished from the superficially similar wolf spider family Lycosidae by eye arrangement: Pisaurina and relatives have all eyes approximately the same size, whereas Lycosidae have two enlarged posterior median eyes. Additionally, pisaurids carry egg sacs with jaws and pedipalps, while lycosids attach egg sacs to their spinnerets. Fishing spiders (Dolomedes) are exceptionally large with long legs adapted for water surface locomotion. Nursery web spiders typically have a more elongated, slender build compared to the stockier wolf spiders.

Habitats span forests, woodlands, wetlands, and riparian zones. Many species favor vertical surfaces—shrubs, trees, tall grass—rather than ground-dwelling. Semi-aquatic members inhabit rocky stream shoals, pond edges, and other freshwater margins. Some species occupy specialized microhabitats: under bark, in window frames, pitcher plants, or bromeliads. The genus Tinus peregrinus occurs in the southwestern U.S. and northern Mexico, found under tree bark near ponds and on building exteriors. Qianlingula species from China inhabit rocky shoals along streams with semi-aquatic hunting behavior.

Worldwide distribution across all continents except Antarctica. In North America, Pisaurina mira ranges from southern Ontario and Quebec to Florida, west to Minnesota, Nebraska, Kansas, Oklahoma, and the Rio Grande Valley of Texas. Tinus peregrinus occurs from southern California to Nevada, east to Texas and Missouri, plus northern Mexico. The genus Dolomedes has very wide distribution. Ancylometes is Neotropical, with one species reaching Central America. Qianlingula species are restricted to China (Hunan, Guangxi, Fujian, Guizhou, Guangdong, Hainan).

Activity patterns vary by species and climate. Pisaurina mira reaches adulthood in spring. Tinus peregrinus egg sacs appear in late July and early August. Auplopus spider wasps (predators) hunt pisaurid spiders from May to October, peaking July–September. Priocnemis minorata preys on nursery web spiders from late March to mid-June, peaking April–May.

Active hunting predators of insects and other arthropods. Pisaurina mira hunts from ambush on foliage, visits outdoor lights to capture attracted insects, and may hunt actively day or night. Dolomedes species are known to capture small vertebrates including frogs, tadpoles, and fish. The family exhibits diverse foraging strategies: web-based hunting, water surface hunting, and vegetation ambush.

Females produce lentil-shaped egg sacs carried with jaws and pedipalps (Cyspius orientalis). Prior to hatching, females construct nursery webs—silk tents amid foliage, typically above ground—where they suspend egg sacs and guard emerging spiderlings until they molt once more and disperse. Cyspius orientalis has a 2–3.5 year life cycle: all individuals mature at the 9th instar, first winter passed as juveniles, second as adults, with some females surviving to a fourth year. Females lay eggs once yearly.

Nursery web construction is the defining behavioral trait: females guard egg sacs and spiderlings in silk tents. Males of Pisaura mirabilis present nuptial gifts—silk-wrapped prey items—to females before copulation, reducing female aggression and extending mating duration. Semi-aquatic species (Dolomedes, Qianlingula) exhibit rapid water surface locomotion using dense leg bristles; Qianlingula species hide under rocks when disturbed or during daylight. Pisaurina mira rests with first two leg pairs held together, responds quickly to motion, and may flee rapidly from danger. Mating in some species involves silk 'veils' binding female legs.

Significant predators of insect pests in yards, gardens, farms, and orchards. Nursery web spiders are beneficial biological control agents despite their intimidating size. Semi-aquatic forms contribute to regulation of aquatic and riparian invertebrate populations, including small vertebrates. Serve as prey for spider wasps (Pompilidae): documented hosts include Priocnemis minorata, Auplopus species, and Caliadurgus hyalinatus (the latter specializing on immature orb-weavers, not pisaurids).

Generally harmless to humans despite large size of some species; not considered dangerously venomous. Pisaurina mira frequently encountered in yards and gardens, sometimes causing alarm due to size. Occasionally enter buildings. Some species (Dolomedes) studied for their remarkable water-walking and diving abilities. Subject of behavioral research on nuptial gift-giving and sexual selection.

• Lycosidae (wolf spiders)Convergent appearance and hunting behavior; distinguished by eye arrangement (enlarged posterior median eyes in Lycosidae, all eyes equal in Pisauridae), egg sac transport method (spinnerets vs. jaws/pedipalps), and ground-dwelling vs. vertical-surface preference

• spiders
• hunting spiders
• nursery web
• fishing spiders
• semi-aquatic
• nuptial gifts
• parental care
• beneficial predators

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bug Eric: A Nursery Web Spider, Pisaurina dubia
• Bug Eric: Spider Sunday: Nursery Web Spider
• Bug Eric: December 2011
• Nuptial Gifts and Other Romantic Gestures of the Bug World
• Bug Eric: Masters of Mud: Auplopus Spider Wasps
• Bug Eric: Priocnemis minorata
• On the Life History of Cyspius orientalis YAGINUMA (Araneae: Pisauridae)
• A new species of Dolomedes Latreille, 1804 (Araneae: Lycosoidea: Pisauridae) from Madagascar
• On males of two poorly known Qianlingula species from China (Araneae, Pisauridae)
• Nukuhiva Berland, 1935 is a troglobitic wolf spider (Araneae: Lycosidae), not a nursery-web spider (Pisauridae)
• The diving and surface-walking behaviour of Dolomedes triton sexpunctatus (Araneida: Pisauridae)
• A revision of the Neotropical spider genus Ancylometes Bertkau (Araneae: Pisauridae)
• Silk Investment in Gifts By Males of the Nuptial Feeding Spider Pisaura Mirabilis (Araneae: Pisauridae)
• Description of the males of Euprosthenops australis Simon, 1898 and Euprosthenopsis pulchella (Pocock, 1902) (Araneae: Pisauridae)