Using Different Methods to Access the Difficult Task of Delimiting Species in a Complex Neotropical Hyperdiverse...

Area of Science:

• Ichthyology
• Molecular Systematics
• Biodiversity Research

Background:

• The Rineloricaria genus, a Neotropical freshwater fish group, faces significant taxonomic challenges due to numerous species and high morphological similarity.
• Accurate species identification is crucial for understanding Neotropical fish diversity and evolutionary history.

Purpose of the Study:

• To clarify species boundaries and identify independent evolutionary units within the Rineloricaria genus.
• To evaluate the effectiveness of integrative taxonomy by combining morphological and molecular data.
• To assess the potential for discovering new species in hyperdiverse fish groups.

Main Methods:

• Analysis of 228 samples representing 53 morphospecies.
• Application of general mixed yule-coalescent (GMYC) analysis.
• Utilizing Barcode of Life Data System (BOLD) analysis for BINs.
• Employing an integrative taxonomy approach combining multiple analytical results.

Main Results:

• GMYC analysis identified 70 distinct evolutionary entities.
• BOLD system analysis revealed 56 unique Barcode Index Numbers (BINs).
• An integrative taxonomy approach identified 73 Operational Taxonomic Units (OTUs), suggesting greater species complexity.

Conclusions:

• The Rineloricaria genus exhibits significant taxonomic complexity, likely containing numerous undescribed species.
• Integrative taxonomy effectively delineates species boundaries and evolutionary units.
• Hyperdiverse fish groups with broad distributions may harbor more evolutionary diversity than currently recognized.