Скачать или смотреть Freshwater Fish Diversity of the Barra del Colorado Wildlife Refuge, Costa Rica | Taegan Perez

Title: Freshwater Fish Diversity of the Barra del Colorado Wildlife Refuge, Costa Rica: Traditional and Molecular Approaches to Biodiversity Investigation
Abstract: As concerns over declines in global biodiversity continue, baseline measures of diversity become increasingly important for effective conservation planning and management. This is especially the case for diverse groups like Neotropical freshwater fishes. Morphology is conventionally used for specimen identification, but this can be inefficient when intra- and interspecific morphological variations overlap, and the challenge can be even greater in highly diverse areas such as Costa Rica. Previous assessments of the diversity of freshwater fishes in Costa Rica were completed using only conventional identification methods. No studies have been done to date to assess the diversity of freshwater fishes in Costa Rica using molecular techniques such as DNA barcoding. We collected 396 specimens in the Barra del Colorado Wildlife Refuge (BCWR) in Costa Rica during 4 expeditions from 2013-2019. We successfully amplified the Cytochrome Oxidase Subunit 1 (coI) gene for 257 specimens. We also obtained morphological identifications from experts for 115 specimens. First, we wanted to test the ability of public databases to identify sequences from BCWR. We found that overall, these databases were able to identify specimens from well resolved, well represented groups, but fell short for comparatively more rare groups. In addition, for taxonomically challenging groups such as those found in the Neotropics, misidentifications were found to be the largest source of error. Due to these results, we resolved to creating a local reference library using an integrative approach. We combined sequences from expertly identified specimens, and critically evaluated public data. We tested the functionality of the library, using sequences from specimens not identified by experts in our collection. We found that our local reference library was more effective in identifying specimens. This project identifies lingering issues with using DNA barcoding for identification and conservation, and presents solutions to combat these issues in the form of curated, reliable, local libraries. As the first baseline measure of the species present in BCWR, this project provides critical information to be used by conservation managers in the effort to protect the neotropics. Finally, this study is the first done in Costa Rica to address species diversity of freshwater fishes using molecular techniques.