Inter-individual variability in equine antibody responses to African snake venoms follows heavy-tailed distributions with implications for antivenom production

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  Inter-individual variability in equine antibody responses to African snake venoms follows heavy-tailed distributions with implications for antivenom production Abstract Variability in the antibody response of horses used for snake antivenom manufacture is well recognized, yet its statistical structure and implications for industrial productivity remain poorly characterized. In this study, we quantified antivenom antibody titers by ELISA in a cohort of 14 horses immunized with venoms from the clinically most important snakes in sub-Saharan Africa. To integrate antibody levels with plasma availability, we calculated the Cumulative Plasma Productivity (CPP) by converting individual plasma volumes into titer-corrected equivalents and sequentially pooling these volumes according to their corrected contribution. Distributional analysis revealed right-skewed, heavy-tailed patterns better approximated by a log-normal model than by a strict Pareto (power-law) form, with approximately 20–3...

The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom

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The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom


Abstract

Spider species distribution in the Cape Floristic Kingdom (CFK) was compiled as part of the South African National Survey of Arachnida (SANSA), whose main aim was to create a relational database for the country’s arachnid fauna. Data from the CFK was extracted from taxonomic and faunistic published papers, as well as unpublished faunistic survey data in national collections. A total of 11 500 records from 130 localities were recorded in the CFK until the end of 2023, representing 62 families, 334 genera and 960 species, with two further families (Synotaxidae and Theridiosomatidae) only known from undescribed species. This represents 42.4% of the total spider fauna of South Africa. For each species, the global and CFK distribution, as well as the level of endemicity and a conservation assessment using the IUCN Red List criteria, are provided. A total of 269 spp. (28.0%) are endemic to the CFK, 49 spp. (5.1%) are of special concern, and 229 spp. (23.9%) are Data Deficient. However, most of the species (682 spp., 71.0%) have a wide distribution with no known threats and are categorised as Least Concern. Salticidae is the most species-rich family (128 spp.), with 30 spp. endemic to the CFK, followed by the Gnaphosidae (107 spp.), Thomisidae (86 spp.) and Lycosidae (49 spp.), while six families are represented by a single species. The last decade has seen an exponential growth in the knowledge of spiders in South Africa, and there are certainly many more species that must still be discovered and described.

A. S. Dippenaar-Schoeman, C. R. Haddad, S. H. Foord & L. N. Lotz (2024) The faunistic diversity of spiders (Arachnida: Araneae) of the South African Cape Floristic Kingdom, Transactions of the Royal Society of South Africa, DOI: 10.1080/0035919X.2024.2324912