Diversity of Intraspecific Patterns of Brain Region Size Covariation in Fish.

This article investigates the patterns of covariation in brain region sizes within and across 10 teleost fish species spanning five orders, aiming to understand how these patterns relate to phylogenetic proximity. The study found that certain brain regions, notably the telencephalon and optic tectum, consistently show strong covariation within species, while others like the olfactory bulb vary more independently. Although not statistically significant, there was a trend indicating that more closely related species share more similar patterns of brain region covariation, suggesting evolutionary conservation of these constraints that may change over long evolutionary timescales. The findings highlight potential genetic and developmental constraints influencing brain morphology evolution and underscore the need for further research into the mechanisms and heritability of brain region covariation.