Resolving phylogeny in Prionotinae: mitogenomic analyses support the genus distinction of Bellator and Prionotus

Species from the genera Bellator and Prionotus (subfamily Prionotinae), commonly known as “searobins”, are marine ray-finned fish with unique motility and prey-detection capabilities, making them ideal evolutionary genetic models. Despite their significance, their phylogeny remains poorly understood. The only existing molecular study on this group classified Prionotus as paraphyletic, in contrast to traditional morphological taxonomy. To definitively resolve their taxonomic status, we conducted the first phylomitogenomic analysis of the group, utilizing 22 complete mitogenomes, including three newly assembled mitogenomes for Bellator militaris, Prionotus alatus, and Prionotus stephanophrys. These three new mitogenomes exhibited a typical vertebrate organization, with the exception of P. stephanophrys, which contains an extra tRNA-Leu and an additional non-coding region. Comparative analysis revealed a minimal mitogenomic divergence (K2P = 0.001) between P. rubio and P. tribulus, suggesting potential mitochondrial introgression, conspecificity, or ongoing divergence, warranting further research to clarify taxonomic boundaries. Our fine-scale partitioned Bayesian Inference and Maximum Likelihood phylogenetic analyses yielded a highly supported congruent topology (BPP = 1.0; UFBoot2 = 100) where Bellator and Prionotus were recovered as reciprocally monophyletic sister groups. These findings definitively resolve the generic status within Prionotinae, providing valuable insights into their evolutionary history, which is fundamental for both evolutionary genetic research and the informed management of these economically valuable species.