ERGA-BGE genome of Gesiella jameensis (Hartmann-Schröder, 1974), an unpigmented blind anchialine cave annelid with deep-sea phylogenetic affinities

The chromosome-level genome of Gesiella jameensis provides a key resource for understanding the genomic basis of adaptation to subterranean environments in annelids. As a cave-restricted annelid species exhibiting specialized phenotypic traits such as depigmentation and eye reduction, this genome provides a foundation for future analyses dissecting of molecular pathways and structural genomic changes underlying convergent evolution to life in darkness. Gesiella jameensis is endemic to the anchialine cave system of La Corona lava tube, including caves such as Los Jameos del Agua and the Túnel de la Atlántida (Lanzarote, Spain), making it highly vulnerable to environmental disturbance. This genome therefore represents a valuable resource for conservation genomics, enabling the future assessment of genetic diversity, population structure, and potential adaptive resilience in these fragile and unique ecosystems. As such, it contributes directly to the preservation and management of anchialine systems, which host highly specialized and often endemic biodiversity. The entire genome sequence was assembled into nine contiguous chromosomal pseudomolecules. This chromosome-level assembly encompasses 8.59 Gb, composed of 3,740 contigs and 1,810 scaffolds, with contig and scaffold N50 values of 7.19 Mb and 1.07 Gb, respectively.