| Abstract: | Although it is frequently assumed that fish possess only simple brain functions, it is becoming increasingly clear that rather complex cognitive abilities are also found in fishes, in particular teleosts. Further studies in teleosts are thus expected to extend our knowledge of cognition from a comparative point of view. The anatomical substrates responsible for such cognitive abilities, however, remain almost entirely unknown in teleosts, offering little clues to understand the evolutionary history or origins of cognition based on neural grounds. Moreover, a firm conclusion on the homology of the teleostean forebrain, in particular the telencephalon, which is a candidate central structure involved in cognitive functions, still remains to be drawn. The present paper introduces an overview of teleost brain morphology as well as different interpretations on the forebrain homology. With the currently available knowledge, it remains possible that the telencephalon of teleosts includes a neocortical homologue. Further studies to determine the homological interrelationships of different brain structures in diverse animals are important for fruitful advancement of comparative cognitive studies. |
