Extreme Enlargement of the Cerebellum in a Clade of Teleost Fishes that Evolved a Novel Active Sensory System (Current Biology)

Sukhum et al. show that evolution of enlarged brains in osteoglossomorph fishes is associated with concerted increases in the sizes of all brain regions, but that active electrosensing evolved alongside independent changes in the sizes of different brain regions. Changes in brain structure may be most likely with the evolution of novel behaviors.