Biodiversity assessment and systematics of neotropical jumping spiders (Araneae: Salticidae)

Abstract

This study combined an intensive site-specific inventory of the spider family Salticidae with an extensive taxonomic review of a subset of the family throughout the Neotropics. This collection of over 8,000 adult salticids from lowland rainforest in Costa Rica's La Selva Biological Station yielded 103 species from 50 genera. At least one genus and ten to fifty percent of these species are new to science. Natural history and range information is presented for the sixteen most abundant species in understory and canopy fogging samples. Species richness estimators predict that quantitative understory sampling captured 88% to 98% of the species accessible to our methods during the survey period. We use this unusually comprehensive empirical dataset to evaluate performance of six parametric and seven nonparametric species richness estimators. Among parametric curve-fitting models, Soberon and Llorente's log model provides the best fit, least bias, and most accurate results at most sample sizes. Of nonparametric estimators, Chao1 and Chao2 most quickly reduce the negative bias all show at small sample sizes. Stratifying sampling by method, habitat, and site improved richness estimation by enabling us to diagnose edges of our target community and its partitions by identifying "leakage" of rare species from other partitions in which these species were common. Stratified sampling also revealed differences in subfamily-level faunal composition across partitions and exposed hints of elaborate niche partitioning among taxa, particularly within the speciose genus Corythalia. This taxonomic revision of the Neotropical genera Cobanus F. O. Pickard-Cambridge 1901 and Sidusa, Peckham and Peckham 1896 shows them to be closely related to one another and almost doubles the size of each. Twenty-four species are newly described here, twelve re-described, three synonymized, two transferred to other genera, and several recognized as being misplaced. This paper provides character matrices for specimen identification and summarizes known distribution and natural history information for all species of Cobanus and Sidusa. Phylogenetic analysis of morphological characters in these species and members of thirty other euophryine genera supports the sister relationship and mutual monophyly of Cobanus and Sidusa, and provides insight into character variation and higher-level relationships within the subfamily Euophryinae.