The common guitarfish (Rhinobatos rhinobatos), protected in Europe and the Mediterranean Sea, was thought to be extinct for over 30 years in the western Mediterranean.This acoustic telemetry receiver array, OP-enabled, has monitored individuals tagged in this area while also contributing detections of other animals (and species) via the ETN. This project was granted technical and financial support from the Ministry for the Ecological Transition and the Demographic Challenge of Spain, the Department of Environment, Universities, Research and Mar Menor of Murcia and the Department of Water, Agriculture, Livestock and Fishing of Murcia.