Figure 7: Dorsal views of the goldfish above and lateral view below. Fish are one of the five most well known classes of vertebrates (animals with backbones). These are mammals, birds, fish, reptiles and amphibians. fish and reptiles have minimal cerebral cortex but a well-developed cerebellum and predominant olfactory lobe. This illustrates the ancient phylogeny of these structures, which we have inherited from our reptilian and amphibian ancestors. They have a strong survival instinct driven by their medulla oblongata and brainstem. Drawn by Sorcha O’Malley.