What is the purpose of fishes characteristics?

Answer 1

Here's a question for you. In addition to living in water, whale sharks, manta rays, moray eels, groupers, gobies, rainbow trout and sea horses have what in common? Clearly these animals vary in size. Some live along the seafloor, while others live in the water column and roam the open sea. Most live in salt water, but one lives in freshwater streams. Some, but not all, are filter feeders. Before you hurt your brain trying to come up with the answer, let me tell you that the answer I am looking for is that all of these creatures are fishes. If you did not realize that, do not despair. You have a lot of company. While many divers know that groupers and gobies are fishes, a whole lot of people fail to realize that sharks, rays, eels and even sea horses are also fishes. To be clear, sharks, rays, eels and sea horses are not just closely related to fishes, they are 100 percent fish.