Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution

  Image Credit: WikiCommons Big Spider, Big Genome: Chromosome-level genome of a North American tarantula (Aphonopelma marxi) and comparative genomics across 300 million years of spider evolution Abstract The comparison of chromosome-level genomes allows biologists to investigate new axes of organismal evolution. Spiders comprise a significant proportion of known arachnid diversity, with many complex morphologies and unique natural histories, yet comparative genomics in spiders has been limited due to the number of available genomes. We present a de novo chromosomal reference genome of a mature male tarantula, Aphonopelma marxi, and comparatively examine spider genome evolution across the Order Araneae. Using PacBio HiFi and Hi-C sequencing, the final 6.5 Gb assembly consists of 17 autosomes, 1 X chromosome, and 127 unplaced scaffolds, with an N50 of 370 Mb and Arachnida (odb10; 2934 genes) BUSCO of 96.7%. By comparing 20 additional spider genomes from 15 families, we find mygalomo...

Geographic distribution of the scorpion fauna in the central Moroccan region of Souss-Massa with potential implications for public health

 


Geographic distribution of the scorpion fauna in the central Moroccan region of Souss-Massa with potential implications for public health

Abstract

Despite the medical importance of North African scorpions, many aspects of their ecology which may be important to understand envenoming patterns throughout their range, remain understudied. The region of Souss-Massa in central Morocco exhibits a high incidence of scorpion envenomings, with 29 437 cases reported between 2005 and 2010, resulting in 32 deaths. In the present study, we provide an updated inventory of scorpions occurring throughout the Souss-Massa region, with additional information about their distribution and notes on preferred habitats for each species observed. Sampling was carried out at 39 stations over a three-year period: June and August 2020, April and June 2022, and July and August 2023. Twelve species belonging to two families were recovered over the course of the study. The families Buthidae and Scorpionidae were represented by eleven and a single species respectively. Overall, this represents 71% of all species reported to occur in the Souss-Massa region. Apart from Androctonus mauritanicusA. bourdoni, A. sergenti and Hottentotta gentili which are present in and around human dwellings, all other species were found in uninhabited areas. Apart from Scorpio mogadorensis, all the species of scorpions we recovered can cause severe envenomation with potentially fatal outcomes. Field-based ecological investigations should be encouraged to gain a more accurate and comprehensive understanding of scorpion distribution patterns and habitat preference. In turn, this will inform the health-science community of the etiological factors responsible for scorpion envenoming.

Salhi, F. et al. (2024) ‘Geographic distribution of the scorpion fauna in the central Moroccan region of Souss-Massa with potential implications for public health’, African Zoology, pp. 1–8. doi: 10.1080/15627020.2024.2323557.