We are not descended from any current day fish or ape. Our ancestors are not around any more, just like your great-great-grandfather is not around (or even moreso.) However, we are apes (or more correctly, they are homo) but it was politically incorrect to write than when the family/genus labels were made. Chimps, Bonobos, Gorillas and Homo all are descended from a now-extinct ape that lived millions of years ago -- and long ago out-competed by his improved descendents.

Likewise all vertebrates descend from early fish. And we have their DNA in our genes. If you went into an African village of black-skinned people, and you met a Chinese couple living there, with Chinese children, would you insist that nonetheless they must be adopted? When you get down deep inside (the DNA) we really do look so very much like our ancestors, and our cousins. So very, incredibly much so that within scientific circles the debate stopped long ago.