Fish is not considered meat, this is why:
As a generic culinary and butchery term of art, "meat" refers to the muscular flesh of a mammal. This is the definition most commonly applied by governments in meat product regulation and food labeling, and in religious rites and rituals.
Because of this I don't consider it meat, also eating fish is very healthy. Even in my culture in which I live, people don't consider fish as meat. I never said that I'm a vegetarian either.
So is poultry meat? Last time I checked, birds are not mammals? You do realize that at the cellular level, a muscle cell from all animals are relatively indistinguishable. They all use a homologous set of genes to achieve the same function. Ultimately, for you to have your fish, an animal must give it's life.
This is something that I've found online. It is not something that I stand by. Like I have said, where I live people don't consider eating meat eating fish. It might not be correct, but it is just how it is. Eating red meat is not healthy, eating fish is though.