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Pachygnatha

Pachygnatha is a genus of long-jawed orb-weavers that was first described by Carl Jakob Sundevall in 1823.

Distribution

Spiders in this genus are found in Eurasia, Africa and North America.

Life style

Pachygnatha species are typically found close to the ground in leaf litter, hollow plant stems, under stones, dead wood, or leaves. They are usually more numerous in damp areas.

Adult spiders are secondarily webless, with only immature spiders constructing orb webs.

African species

Very little is known about the biology and behaviour of Afrotropical species. Studies have shown that Pachygnatha species are found mainly in the lower litter layer, with Pachygnatha leleupi being the most common species. This species occurs throughout equatorial Africa at high altitudes, from Cameroon to Malawi. Specimens were much more abundant where water was available.

Description

The carapace bears eyes that are closely grouped, with median eyes separated by their own diameter. The chelicerae are notably large and consistently feature three teeth on the anterior margin in females. In males, the chelicerae are modified and expanded, sometimes bearing a spur on the outside above the base of the fang. The abdomen is subspherical and slightly flattened.

The dorsal surface displays a folium bordered by dark marks with adjacent silver spots. The folium typically has posterior lobes, and the cardiac mark is sometimes outlined by dark pigment or features a median dark mark. Paired white spots are often present. The legs are rather thin and lack macrosetae.

Species

, this genus includes 44 species and two subspecies:

In synonymy:

  • P. gaoi <small>Zhu, Song & Zhang, 2003</small> = Pachygnatha amurensis <small>Strand, 1907</small>
  • P. kuratai <small>Levi, 1951</small> = Pachygnatha dorothea <small>McCook, 1894</small>
  • P. nipponica <small>(Kishida, 1936)</small> = Pachygnatha quadrimaculata <small>(Bösenberg & Strand, 1906)</small>
  • P. sewardi <small>Chamberlin & Ivie, 1947</small> = Pachygnatha clercki <small>Sundevall, 1823</small>
  • P. yiliensis <small>(Hu & Wu, 1985)</small> = Pachygnatha degeeri <small>Sundevall, 1830</small>

References