A pseudoscorpion clinging to a cave salamander: phoresy or failed predation?

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  A pseudoscorpion clinging to a cave salamander: phoresy or failed predation? Abstract Pseudoscorpions are well known for phoretic associations with arthropods, but interactions with amphibians are rarely documented. Here we report a pseudoscorpion attached to the left palpebral region of an adult male Italian cave salamander, Speleomantes italicus , observed during a visual survey in a karst cave in Tuscany, Italy. The pseudoscorpion, assigned on the basis of visible morphology and locality to Chthonius cf. elongatus , was grasping a minute cutaneous fold on the lower margin of the left upper eyelid with one chela while the salamander moved slowly over the rock surface. No handling was performed and the initial contact between the two animals was not observed. The event therefore cannot be interpreted unambiguously, but may represent opportunistic phoresy or defensive attachment following a failed predation attempt. To our knowledge, this is the first published observation of a ...

Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders

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Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders

ABSTRACT

Pardosa spiders, belonging to the wolf spider family Lycosidae, play a vital role in maintaining the health of forest and agricultural ecosystems due to their function in pest control. This study presents chromosome-level genome assemblies for two allied Pardosa species, P. laura and P. agraria. Both species' genomes show a notable expansion of helitron transposable elements, which contributes to their large genome sizes. Methylome analysis indicates that P. laura has higher overall DNA methylation levels compared to P. agraria. DNA methylation may not only aids in transposable element-driven genome expansion but also positively affects the three-dimensional organisation of P. laura after transposon amplification, thereby potentially enhancing genome stability. Genes associated with hyper-differentially methylated regions in P. laura (compared to P. agraria) are enriched in functions related to mRNA processing and energy production. Furthermore, combined transcriptome and methylome profiling has uncovered a complex regulatory interplay between DNA methylation and gene expression, emphasising the important role of gene body methylation in the regulation of gene expression. Comparative genomic analysis shows a significant expansion of cuticle protein and detoxification-related gene families in P. laura, which may improve its adaptability to various habitats. This study provides essential genomic and methylomic insights, offering a deeper understanding of the relationship between transposable elements and genome stability, and illuminating the adaptive evolution and species differentiation among allied spiders.

Zuo, Q., Wu, B., Sun, N., Ren, Y., Fan, Z., Wang, Y., Tan, B., Luo, B., Irfan, M., Huang, Q., Shen, J., & Zhang, S. Genomic and Methylomic Signatures Associated With the Maintenance of Genome Stability and Adaptive Evolution in Two Closely Allied Wolf Spiders. Molecular Ecology Resources, e14071. https://doi.org/10.1111/1755-0998.14071