Broad-Scale Climatic Gradients Drive Multiple Facets of Scorpion Beta Diversity in Northeastern Brazil

  Broad-Scale Climatic Gradients Drive Multiple Facets of Scorpion Beta Diversity in Northeastern Brazil ABSTRACT Aim Beta diversity analyses clarify mechanisms structuring ecological communities, but their multidimensional facets remain poorly explored in arthropods. Here, we quantified taxonomic, phylogenetic, and functional beta diversity in scorpions, partitioned these facets into species replacement and richness differences, and evaluated the relative importance of spatial structure and environmental conditions in driving community assembly. Location Northeastern Brazil, South America. Taxon Scorpions (Arachnida: Scorpiones). Methods Taxonomic beta diversity was estimated using species presence across 70 sites in northeastern Brazil. Phylogenetic turnover was calculated from a multi-locus molecular tree, and functional beta diversity was derived from morphometric and ecological traits. All beta diversity facets were decomposed into replacement and richness-difference component...

Miniaturization does not change conserved spider anatomy, a case study on spider Rayforstia (Araneae: Anapidae)

 


Miniaturization does not change conserved spider anatomy, a case study on spider Rayforstia (Araneae: Anapidae)

Abstract

Miniaturization is an evolutionary trend observed in many animals. Some arachnid groups, such as spiders and mites, demonstrate a strong tendency toward miniaturization. Some of the most miniaturized spiders belong to the family Anapidae. In this study, using light and confocal microscopy and 3D modelling, we provide the first detailed description of the anatomy of a spider of the genus Rayforstia, which is only 900 µm long. In comparison with larger spiders, Rayforstia has no branching of the midgut in the prosoma and an increased relative brain volume. In contrast to many miniature insects and mites, the spider shows no reduction of whole organ systems, no allometry of the digestive and reproductive systems, and also no reduction of the set of muscles. Thus, miniature spider shows a more conserved anatomy than insects of a similar size. These findings expand our knowledge of miniaturization in terrestrial arthropods.

Propistsova, E. A., Makarova, A. A., Eskov, K. Y., & Polilov, A. A. (2023). Miniaturization does not change conserved spider anatomy, a case study on spider Rayforstia (Araneae: Anapidae). Scientific Reports, 13(1), 1-14. https://doi.org/10.1038/s41598-023-44230-3