Throughout 2019, multiple large Rathbunella specimens were collected from recreational hook and line fishermen off San Diego County, California, USA. The individuals were larger than the previously reported maximum size for Rathbunella and exhibited a dark coloration known but not usually depicted for the genus. Herein, we provide morphological and molecular evidence that these specimens are Bluebanded Ronquils, Rathbunella hypoplecta, and we increase the maximum size of the species to 242 mm standard length. We provide descriptions of the specimens and the dark-phase coloration and demonstrate that dark and light-phase individuals are not genetically different.