Remarkable micro-endemism and high congeneric richness: eight new cave-restricted species of Pseudochthonius Balzan, 1892 (Pseudoscorpiones, Chthoniidae) from the Brazilian semi-arid

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  Remarkable micro-endemism and high congeneric richness: eight new cave-restricted species of Pseudochthonius Balzan, 1892 (Pseudoscorpiones, Chthoniidae) from the Brazilian semi-arid Abstract Eight new species of pseudoscorpions belonging to the genus Pseudochthonius Balzan, 1892 are described from the semi-arid region of Brazil. Comprehensive morphological descriptions, diagnostic characters, detailed illustrations, and ecological remarks of the habitats are provided for Pseudochthonius celestialis sp. nov., P. caritas sp. nov., P. patientia sp. nov., P. temperantia sp. nov., P. diligentia sp. nov., P. castitas sp. nov., P. humilitas sp. nov., and P. benignitas sp. nov. In addition, we present a brief discussion of the potential factors underlying the remarkable congeneric species richness observed in this geographically restricted region, as well as the principal threats faced by these species. These findings underscore the importance of conserving caves in order to pr...

One time only: determining spider diversity along a latitudinal gradient in South Africa's arid Succulent Karoo and Desert biomes using a rapid sampling protocol

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One time only: determining spider diversity along a latitudinal gradient in South Africa's arid Succulent Karoo and Desert biomes using a rapid sampling protocol

Abstract

The Succulent Karoo Biome (SKB) is distributed in the western and southern parts of South Africa and is an entirely arid global biodiversity hotspot, but it is severely undersampled for spiders. To address this gap, we used a standardized sampling protocol to collect arachnids from four biotopes (open plain, riparian vegetation, east- and west-facing mountain slopes) using three methods along a latitudinal gradient of five adjacent degree-squares in South Africa's arid western interior to determine how latitude, biotopes, sampling methods and climate affect spider assemblages and diversity. A total of 6497 spiders were collected, representing 305 species and 39 families. Beating yielded the most individuals but the fewest species (n = 3710, S = 130), hand collecting in litter the most species and intermediate numbers (n = 1646, S = 213) and hand collecting from rocks collected the lowest numbers and intermediate species richness (n = 1141, S = 150). Abundance and species richness showed a general bell-shaped pattern along the transect, peaking at Akkerendam Nature Reserve (n = 1839, S = 129). Hand collecting from leaf litter was the most important contributor to spider species richness, with a lower species accumulation rate than beating or hand collecting from rocks. Spider composition from rocks and leaf litter showed some overlap, whereas beating sampled a highly distinct fauna across sites. In total, 519 specimens were sequenced (cytochrome c oxidase subunit I, COI), and this data is publicly available on the SPIZA project on the Barcode of Life Data System (BOLD).
Haddad, C. R., Van der Mescht, A., Booysen, R., Christiaan, R., Stander, A., Dippenaar-Schoeman, A. S., Van Aardt, A. C., & Foord, S. H. (2026). One time only: Determining spider diversity along a latitudinal gradient in South Africa's arid Succulent Karoo and Desert biomes using a rapid sampling protocol. Acta Oecologica, 132, 104186. https://doi.org/10.1016/j.actao.2026.104186