Species Diversity Assessment of the Flatfish Genus Laeops (Carangiformes: Bothidae) in Taiwan, with the Resurrection of L. kitaharae

Species Diversity Assessment of the Flatfish Genus Laeops (Carangiformes: Bothidae) in Taiwan, with the Resurrection of L. kitaharae

The bothid genus Laeops currently comprises nine recognized species, with one to three species reported from Taiwanese waters. However, the validity of L. kitaharae, which was recently synonymized with L. parviceps based on morphology, has long been debated. This study applies integrative taxonomy to resolve the taxonomic status of Laeops species occurring in Taiwanese waters. A total of 57 Laeops specimens were collected from Taiwan and other localities across the Indo-West Pacific region and analyzed using both morphological and molecular methods. A phylogenetic tree was reconstructed from 105 mitochondrial COI gene sequences obtained in this study and compiled from online sources. The results reveal that Laeops is not monophyletic, instead forming two distinct lineages: Laeops I (L. nigromaculatus) and Laeops II (the remaining sampled species). Further species delimitation analyses using ASAP and bPTP consistently identified seven Operational Taxonomic Units (or inferred species), supporting L. kitaharae and L. parviceps as distinct species, with a genetic divergence of 9.7˜ at the COI locus. Morphological examinations based on available voucher specimens, including type series, indicate that L. kitaharae differs from L. parviceps by having fewer dorsal- and anal-fin rays (D: 100–103 vs. 105–109; A: 78–83 vs. 85–90) and a shorter snout (1.6–2.1˜ SL vs. 2.2–3.4˜ SL). A re-examination of the type specimens suggests that L. tungkongensis, a species previously described from four specimens collected in Donggang, southwestern Taiwan, is conspecific with L. parviceps, rather than L. clarus, as previously proposed. Consequently, we resurrect L. kitaharae as a valid species and synonymize L. tungkongensis with L. parviceps. Accordingly, three Laeops species (L. kitaharae, L. lanceolata, and L. parviceps) are confirmed to occur in Taiwan. Furthermore, genetic references and an updated identification key for Laeops II are provided. This research has been registered in ZooBank under the identifier: urn:lsid:zoobank.org:pub:B21F2AB6-8C06-4CE9-8024-B45C2ABDF48D.