Multivariate and Geometric Morphometrics Reveal Morphological Variation Among Sinibotia Fish

Area of Science:

• Ichthyology
• Morphology
• Phylogenetics

Background:

• Sinibotia species exhibit high morphological similarity and close phylogenetic relationships, complicating traditional identification methods.
• Frequent sympatric occurrences and comparable body patterns further challenge accurate species differentiation in Sinibotia.

Purpose of the Study:

• To assess and differentiate morphological variations among five Sinibotia species using advanced morphometric techniques.
• To investigate the utility of multivariate morphometrics (MM) and geometric morphometrics (GM) in resolving taxonomic ambiguities within the Sinibotia genus.

Main Methods:

• Employed multivariate morphometrics (MM) and geometric morphometrics (GM) on 40 morphological traits and 34 landmarks from five Sinibotia species.
• Utilized discriminant function analysis (DFA) for MM and canonical variate analysis (CVA) and relative distortion analysis for GM.

Main Results:

• MM and GM analyses successfully differentiated Sinibotia species, with S. robusta showing distinct traits compared to S. pulchra and S. zebra.
• Morphological variations were primarily observed in snout length, nasal snout distance, head depth, body depth, caudal fin length, and dorsal fin length.
• MM quantified linear size differences, while GM effectively captured and visualized complex shape variations.

Conclusions:

• Combined MM and GM evidence significantly aids in the accurate identification of Sinibotia species.
• These findings enhance understanding of phylogenetic relationships and ecological adaptations within the genus.
• The study provides a strong theoretical basis for the conservation and sustainable utilization of Sinibotia species.