The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems

Posted by
  The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems Abstract Coastal dune ecosystems support endemic trapdoor spiders, yet population data for these species are limited. We conducted the first coastal dune trapdoor spider population estimation surveys at Moss Landing State Beach (California) and for Aptostichus stephencolberti Bond 2008 at Sunset State Beach using randomly selected 1m 2 quadrats across ~26,000 m 2 per site. Burrow densities were similar between sites (Sunset: 0.287 burrows/m 2 ; Moss: 0.453 burrows/m 2 ), yielding estimated population sizes of ~35,206 and ~30,959 individuals, respectively. However, spatial analyses revealed contrasting patterns of burrow distribution. At Sunset State Beach, burrow presence was strongly associated with vegetation and occurred closer to plants, despite vegetation being randomly distributed. In contrast, no vegetation–burrow association was detected at Moss Landing, alth...

Two new species of the long-jawed orb-weaving spider genus Pachygnatha Sundevall, 1823 (Araneae, Tetragnathidae) from southern China

Posted by

 


Two new species of the long-jawed orb-weaving spider genus Pachygnatha Sundevall, 1823 (Araneae, Tetragnathidae) from southern China

Abstract


The spider genus Pachygnatha Sundevall, 1823 is widely distributed in the world, exhibiting higher species diversity in Palaearctic and Nearctic regions. Two new Pachygnatha species from southern China are described based on males and females: Pachygnatha shengtangensis sp. nov. and Pachygnatha unciniformis sp. nov. Detailed descriptions, color photographs and line drawings of the two new species, and a distribution map of Chinese Pachygnatha are provided. Furthermore, the COI sequences of the new species, and the p-distances are also presented between seven Pachygnatha species including five known and the two new species. The embolic medial groove, previously recorded and described in the genus Glenognatha Simon, 1887, is also present in the two new species, representing the first record of this structure in the genus Pachygnatha.

Huang, Z. G., Wu, Y. C., Yin, H. Q., Xu, X. & Chen, J. H. (2024). Two new species of the long-jawed orb-weaving spider genus Pachygnatha Sundevall, 1823 (Araneae, Tetragnathidae) from southern China. Zootaxa 5555(3): 385-406. doi:10.11646/zootaxa.5555.3.4