Assessing Current Fish Diversity in the Yellow River Basin by Integrating Large-Scale Barcoding and Morphological...

Area of Science:

• Ichthyology
• Molecular Ecology
• Conservation Biology

Background:

• Fish populations in the Yellow River (YR) basin face sharp declines due to human activities.
• Existing literature shows discrepancies in the systematic classification of YR fish species.
• A standardized DNA barcode database for YR fish is crucial for accurate biodiversity assessment.

Purpose of the Study:

• To construct the first comprehensive DNA barcode database for fish in the Yellow River basin.
• To assess fish diversity and taxonomic accuracy using molecular data.
• To provide insights into the underestimation of fish diversity in the region.

Main Methods:

• Collected samples from 127 sites in the YR basin between 2013 and 2023.
• Constructed a DNA barcode database with 3011 sequences representing 110 fish species.
• Identified 124 operable taxonomic units (OTUs) using four sequence-based species classification methods.

Main Results:

• The DNA barcode database included 110 species and 124 OTUs.
• Barcode and morphological data were consistent for 77.1% of the species (84 species).
• Discrepancies were found, with some species assigned unique OTUs and widespread species split into multiple OTUs.

Conclusions:

• Fish diversity in the Yellow River basin has been significantly underestimated.
• The constructed DNA barcode database offers new insights into regional fish diversity.
• Further detailed investigations are necessary to fully understand and conserve YR fish populations.