Unveiling the genetic blueprint of a desert scorpion: A chromosome-level genome ofHadrurus arizonensisprovides the first reference for Parvorder Iurida

Over 400 million years old, scorpions represent an ancient group of arachnids and one of the first animals to adapt to life on land. Presently, the lack of available genomes within scorpions hinders research on their evolution. This study leverages ultra-long nanopore sequencing and Pore-C to generate the first chromosome level assembly and annotation for the desert hairy scorpion, Hadrurus arizonensis . The assembled genome is 2.23 Gb in size with an N50 of 280 Mb. Pore-C scaffolding re-oriented 99.6% of bases into nine chromosomes and BUSCO identified 998 (98.6%) complete arthropod single copy orthologs. Repetitive elements represent 54.69% of the assembled bases, including 872,874 (29.39%) LINE elements. A total of 18,996 protein-coding genes and 75,256 transcripts were predicted, and extracted protein sequences yielded a BUSCO score of 97.2%. This is the first genome assembled and annotated within the family Hadruridae, representing a crucial resource for closing gaps in genomic knowledge of scorpions, resolving arachnid phylogeny, and advancing studies in comparative and functional genomics. Significance Genomic resources for the study of arachnids are limited. To date, only four scorpion genomes have been published; none of these are chromosome-level assemblies, and all four belong to a single family, Buthidae. In this study, we assembled the first chromosome-level, annotated genome for a non-buthid species ( Hadrurus arizonensis ). This high quality reference will provide a critical resource for comparative and functional genomics and contribute to the understanding of arachnid evolution.