Abstract

JIMENEZ, María Luisa  and  NAVARRETE, José Gabriel. Ground surface spider fauna in an arid tropical community in Baja California Sur, Mexico. Rev. Mex. Biodiv. [online]. 2010, vol.81, n.2, pp.417-426. ISSN 2007-8706.

Seasonal distribution, specific richness, and diversity of xeric shrub ground spiders were studied at a site in the Cape Region. Weekly collections of spiders were made in 1991-1992 using pit-fall traps. We captured 4 322 specimens in 53 families. Families with the highest number of individuals were: Miturgidae (42%) Oonopidae (23.5%), Caponiidae (8.0%), and Gnaphosidae (7.9%). The most abundant species were Syspira tigrina Chamberlin (37.1%); Oonops nov. sp. (13.7%), Scaphiella hespera Chamberlin (7.8%), and Tarsonops sternalis Chamberlin (5.2%), representing 63.7% of the total specimens captured. Gnaphosidae was the richest in species (11) followed by Salticidae (7). Species richness was nearly constant during all the year, with a small increase in summer (29) and a small decline in winter (24); seasonal diversity was also constant (H'= 3.3-3.7). The highest relative abundance occurred in spring and autumn and the highest specific richness was in autumn. The diversity and relative abundance of spiders were high, in spite of the high abundance of Miturgidae. Distribution of the major species had a marked seasonality.

Keywords : ground spiders; Baja California Sur; desert shrub.