Brain growth patterns in four European cyprinid fish species (Cyprinidae, Teleostei): roach (Rutilus rutilus), bream (Abramis brama), common carp (Cyprinus carpio) and sabre carp (Pelecus cultratus).

This study compares brain growth in 4 species of cyprinids, each distinctly different in adult brain morphology: roach have generalized brains; bream are characterized by well-developed visual, octavolateralis and gustatory brain regions; common carp show chemosensory (gustatory)-dominated brains, and sabre carp octavolateralis-dominated brains. The growth patterns of 16 regions relative to total brain volume were investigated by computer-aided quantitative histology to illustrate internal brain allometries. In all species the tectum opticum decreases in relative size during growth, whereas the corpus cerebelli increases. In bream and common carp, primary taste centers steadily increase in relative size during growth. In most if not all fish, the brain attains no definite final morphology. Lifelong, growth-related shifts in relative sizes of primary sensory regions may reflect lifelong shifting sensory capabilities.