Integrated Molecular and Morphological Analyses Resolve Long‐Standing Classification Challenges in the Sinistral Flatfish Family Bothidae (Teleostei: Carangiformes)

ABSTRACT The flatfish family Bothidae comprise 170 currently recognised species in 20 genera, classified under two subfamilies. Although previous morphological and molecular studies have supported the monophyly of the family, its intrafamilial relationships remain largely unexplored, and the monophyly of the 20 existing genera has yet to be thoroughly evaluated. This study aims to address these long‐standing systematic issues, particularly at the generic level, and to elucidate the sister‐group relationships within Bothidae using a comprehensive set of samples of 87 morphospecies across 19 genera, and DNA sequence data from two mitochondrial and three nuclear gene markers. Our results reveal that the subfamily Bothinae is paraphyletic with respect to monophyletic Taeniopsettinae. Additionally, ‘Bothinae’ can be subdivided into three main clades (Bothinae 1–3). At the generic level, while Grammatobothus is resolved as monophyletic (=Bothinae 1) and as the sister group to the remaining bothids, four other specious genera— Arnoglossus , Laeops , Parabothus , and Psettina —are not. To resolve these taxonomic inconsistencies, we integrate evidence from phylogeny, morphology, and biogeography. Consequently, we propose elevating Taeniopsettinae to family status, establishing two new families—Monolenidae (=Bothinae 2) and Grammatobothidae—each comprising a single genus, and restricting the family Bothidae to Bothinae 3. We also refine the usage of the valid generic names Arnoglossus (= Arnoglossus V), Laeops (= Laeops II), Parabothus (= Parabothus III), and Psettina (= Psettina III), and recommend the resurrection of previously synonymised bothid genera as well as the establishment of new genera. These taxonomic revisions are ongoing and will be elaborated upon in a forthcoming study.