Fish are not reptiles nor are they amphibians.
Fish are their own classification of animals and are aquatic vertebrates.
Fish are a group of animals which are completely aquatic vertebrates that have gills, scales, swim bladders to float, most produce eggs, and are ectothermic.
Sharks, stingrays, skates, eels, puffers, seahorses, clownfish are all examples of fishes.
The 7 levels are kingdom, phylum, class, order, family, genus, and species, where the kingdom is the largest and most general.
A fish is an animal that lives only in the water, whereas a reptile lives in both land and water.
A fish is an aquatic vertebrate that is cold blooded or ectothermic.
The reptile is also a cold blooded animal that is covered by scutes or scales.
Fish also have scales, although they are absent in cartilaginous fish.
Amphibians, reptiles, mammals, and birds evolved after fish. The first amphibians evolved from a lobe-finned fish ancestor about 365 million years ago.
Snakes are reptiles and not amphibians.
Other animals that are reptiles besides just snakes are crocodiles, alligators, lizards and turtles.
Amphibians on the other hand are vertebrates (animals with backbones) that are able, when adult, to live both in water and on land.
And unlike fish, amphibians can also breathe atmospheric oxygen through lungs, and they differ from reptiles in that they have soft, moist, usually scale-less skin, and have to breed in water.
Animals that are amphibians include True Frogs, Tree Frogs, South Asian Frogs, Newts, Pacific Giant Salamanders, Hyla, Rhacophorus.