RNA-seq of the Endangered Spanish toothcarp Apricaphanius iberus

The ability of species to adapt is essential for survival in rapidly changing environments, especially those facing pressures from anthropogenic activities and climate change. Conservation strategies often involve delineating management units using genomic data to safeguard genetically distinct populations. This study examined the Spanish toothcarp (Aphanius iberus), an endangered killifish endemic to the Iberian Peninsula, where habitat loss, as a result of agricultural and urban development, has severely impacted its survival. A SNP-based genetic analysis of 176 individuals across 18 locations revealed highly structured populations, low genetic diversity, and limited gene flow. Based on these findings, nine Operational Conservation Units (OCUs) were recommended to guide management efforts. The results underscore the need for targeted ecological and genetic strategies based on management units that will enhance the conservation of threatened killifish species worldwide.