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

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  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...

Paranita, a new genus of spiders from northeastern Argentina (Araneae, Trachelidae)

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Paranita, a new genus of spiders from northeastern Argentina (Araneae, Trachelidae)

Abstract


Paranita, a new spider genus in the family Trachelidae, is described with two new species, Paranita paulae sp. n. and Paranita inesae sp. n., both from grasslands and marshes of the Paraná and Uruguay Rivers in northeastern Argentina. Paranita species are similar to those of the genera Orthobula and Capobula in having abundant spines on the tibia, metatarsus and tarsus of the two pairs of anterior legs, as well as large pores on the surface of the carapace and a peculiar morphology of the claw lever of the legs. Phylogenetic analysis of molecular sequences and morphological data suggests that Paranita is not closely related to those genera and, therefore, these similarities would be evolutionary convergences.

RAMÍREZ, Martín J.; GRISMADO, Cristian. Paranita, a new genus of spiders from northeastern Argentina (Araneae, Trachelidae). Revista del Museo Argentino de Ciencias Naturales nueva serie, [S.l.], v. 26, n. 1, p. 47-68, may. 2024. ISSN 1853-0400. Available at: <http://revista.macn.gob.ar/ojs/index.php/RevMus/article/view/824>. Date accessed: 28 May. 2024.