If 80% of what are called ‘fish’ aren’t ‘pisces’, maybe its time to abandon the soppy shorthand that the definition of an ancient word is simply defined by a modern term. Fish =/= pisces. Get over it. Making that false presumption only destroys your ability to read Shakespeare, the prophet Jonah, and any other source where sea creatures are called ‘fish.’
These are the same kinds of folks who would say that peanuts aren’t nuts and that tomatoes aren’t vegetables. I expect one of them will be shot in a pub one day while arguing how much beer should be in a pint.