Comparing Approaches to Specimen Identification using Neotropical Freshwater Fishes in the Barra del Colorado Wildlife Refuge, Costa Rica

As global biodiversity declines continue, conservation efforts are increasingly important in megadiverse areas such as the Neotropics where biodiversity is especially imperiled. The accurate identification of specimens is critical to successful conservation plans. However, in groups such as freshwater fishes, different identification methodologies have documented challenges. Using a biodiversity survey of fishes from the Barra del Colorado Wildlife Refuge in northeastern Costa Rica, we compared: (1) morphological identifications in the field, (2) morphological identifications in the lab by experts, (3) DNA barcode-based identifications, and (4) identifications based on an integrative approach. Our results suggest that both barcode-based identifications and field morphological identifications provided fewer correct species identifications than lab identifications performed by experts using morphology. We attribute shortfalls of DNA barcoding in this case to the misidentification of reference material, the use of outdated taxonomy for references sequences, and the non-uniform representation of groups in public databases across taxa. We suggest the use of an integrative approach to identify freshwater fishes in Costa Rica and other megadiverse areas of the Neotropics where similar issues with public barcode reference libraries exist. We also recommend the creation of regional curated barcode reference libraries to aid in the identification of traditionally difficult to identify species/specimens. We also provide the most up to date species list for the ichthyofauna of the Barra del Colorado Wildlife Refuge identifying 51 species from 42 genera, 21 families, and 17 orders. Generating accurate species lists for protected areas and areas of importance will provide conservation practitioners with effective tools for tracking diversity changes over time.