Genetic and taxonomic data corroborate the existence of lemon shark, Negaprion brevirostris (Carchariniformes: Carcharhinidae) (Poey, 1868) in Coiba National Park, Panama

Abstract For almost 2 years community structure, characterization and identification of the main fish species from the largest estuaries of Coiba National Park have been the focus of our research interest. Among selachii elasmobranchs (sharks), three common species ( Carcharhinus limbatus , Carcharhinus leucas , and Sphyrna lewinii ) have been reported during our fish collection campaigns in San Juan, Rio Negro and Boca Grande estuaries. These three species plus the white tip reef shark, Triaenodon obesus, and the nurse shark, Ginglymostoma cirratum , have been previously listed as frequent along the islands of Coiba archipelago based on visual census and environmental DNA list provided by UNESCO in collaboration with COIBA AIP Scientific Station. From February to October of 2025, six young-of-the-year (YOY) individuals were tentatively identified as lemon shark ( Negaprion brevirostris ), a species non-reported in this area before, were collected in Boca Grande estuary (two individuals during our dry season sampling campaign (February) and four individuals during the wet season (August–October)). Taxonomic and genetic data analysis support that collected individuals corresponded to lemon sharks, N. brevirostris . To corroborate morphological identification, genetic identification of five individuals was conducted using PCR amplification and product sequencing of a mitochondrial gene segment, cytochrome oxidase I (COI) and of the non-coding mitochondrial segment (control region). Sequences from both DNA segments showed a 99.17% and 99.83% similarity with GenBank referenced sequences for N. brevirostris . For COI N. brevirostris sequences accession numbers were generated and deposited in GenBank: PX453691, PX453712, PZ043670, and PZ036798. These are the first sequences deposited in GenBank for the region and for Coiba National Park. This is also the first confirmed report of the presence of this species in waters of Coiba National Park and in any other of the islands of the Eastern Tropical Pacific marine corridor. Therefore, these are the first reported DNA sequences deposited on GenBank of this species for Panama’s Pacific waters and for the corridor. This information will enable scientists to compare these sequences with reference data from other regions and along the Eastern Tropical Pacific allowing assessment of philopatric behavior and local and regional connectivity patterns. The results will also be essential for informing new management and monitoring strategies in Coiba National Park, including the designation of the Boca Grande estuary as a nursery area and the potential establishment of a shark sanctuary.