Distributional Notes on Three Wolf Spider Species (Araneae: Lycosidae) Recorded for the First Time in Diyala Province, Iraq

Posted by
  Distributional Notes on Three Wolf Spider Species (Araneae: Lycosidae) Recorded for the First Time in Diyala Province, Iraq Abstract This study presents new distributional data for three wolf spider species (Araneae: Lycosidae) from Diyala Province in eastern Iraq. Specimens were gathered from different districts and habitats between July 2025 and June 2026. The species Arctosa tbilisiensis Mcheidze, 1946, Lycosa piochardi Simon, 1876, and Wadicosa fidelis (O. Pickard-Cambridge, 1872) are recorded for the first time in Diyala, extending their known ranges within Iraq. The paper describes key diagnostic morphological features and includes information about the examined specimens and their local distributions. These findings improve knowledge of the distribution of Iraqi Lycosidae and reveal that Diyala Province, despite its habitat variety, remains insufficiently studied. The records serve as a valuable baseline for future taxonomic, faunistic, and ecological research on spiders i...

Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands

Posted by

 


Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands

ABSTRACT

The spider genus Dysdera has undergone a remarkable diversification in the oceanic archipelago of the Canary Islands, with ~60 endemic species having originated during the 20 million years since the origin of the archipelago. This evolutionary radiation has been accompanied by substantial dietary shifts, often characterised by phenotypic modifications encompassing morphological, metabolic and behavioural changes. Hence, these endemic spiders represent an excellent model for understanding the evolutionary drivers and to pinpoint the genomic determinants underlying adaptive radiations. Recently, we achieved the first chromosome-level genome assembly of one of the endemic species, D. silvatica, providing a high-quality reference sequence for evolutionary genomics studies. Here, we conducted a low coverage-based resequencing study of a natural population of D. silvatica from La Gomera island. Taking advantage of the new high-quality genome, we characterised genome-wide levels of nucleotide polymorphism, divergence and linkage disequilibrium, and inferred the demographic history of this population. We also performed comprehensive genome-wide scans for recent positive selection. Our findings uncovered exceptionally high levels of nucleotide diversity and recombination in this geographically restricted endemic species, indicative of large historical effective population sizes. We also identified several candidate genomic regions that are potentially under positive selection, highlighting relevant biological processes, such as vision and nitrogen extraction as potential adaptation targets. These processes may ultimately drive species diversification in this genus. This pioneering study of spiders that are endemic to an oceanic archipelago lays the groundwork for broader population genomics analyses aimed at understanding the genetic mechanisms driving adaptive radiation in island ecosystems.

Escuer, P., Guirao-Rico, S., Arnedo, M. A., Sánchez-Gracia, A., & Rozas, J. Population Genomics of Adaptive Radiations: Exceptionally High Levels of Genetic Diversity and Recombination in an Endemic Spider From the Canary Islands. Molecular Ecology, e17547. https://doi.org/10.1111/mec.17547