Building a Body Shape Morphospace of Teleostean Fishes.

Area of Science:

• Ichthyology
• Evolutionary Biology
• Morphometrics

Background:

• Quantifying 3D body shape across diverse fish species is crucial for understanding evolutionary patterns.
• Existing datasets often lack comprehensive 3D morphological data for teleost fishes.

Purpose of the Study:

• To present a novel 3D body shape dataset for teleost phylogeny.
• To analyze teleost body shape morphospace and identify evolutionary hotspots.
• To investigate the primary axes of morphological evolution in teleosts.

Main Methods:

• Data collection on 16,609 specimens from 6,144 species at the Smithsonian National Museum of Natural History.
• Application of phylogenetic comparative methods and log shape ratios for body-size correction.
• Analysis of 3D body shape data to describe morphospace and evolutionary rates.

Main Results:

• Fish width represents the primary axis of morphological evolution, spanning a continuum from laterally compressed to flattened body shapes.
• Elongation is the secondary axis of variation, particularly within narrow-bodied forms.
• Fastest rates of shape evolution observed in notothenioids, scorpaeniforms, and freshwater elephantfishes.

Conclusions:

• The 3D body shape dataset provides a foundation for investigating factors driving shape diversification in teleosts.
• Body width and elongation are key dimensions shaping teleost morphology.
• Future research can integrate biomechanical principles to link body shape with ecological performance.