The relation between the tiger and the goldfish is that they are both animals that fall into the category of vertebrates. This means that both creatures have spines, and internal bone structure. This is a trait that distinguishes them from the invertebrates that have no spine and bone structure, like the octopus for example, or from the creatures that have an exoskeleton, which means they have a bone structure that is covering the body, but not inside the body itself, like the scorpions for example.