What is the meaning of Moonfish?

Any of various species of fish of a round appearance in several families:

1. Any of species Mene maculata (razor moonfish), sole accepted, extant species of family Menidae, of tropical coastal waters of the Indo-Pacific area;
2. A platyfish, of either of Xiphophorus maculatus or X. variatus (family Poeciliidae).

   Any of species Mene maculata (razor moonfish), sole accepted, extant species of family Menidae, of tropical coastal waters of the Indo-Pacific area;

   A platyfish, of either of Xiphophorus maculatus or X. variatus (family Poeciliidae).

   Any member of most species of the genera Selene and Paraselene (family Carangidae).

   Any of genus Lampris of opahs (family Lamprididae);

   Any of species Mola mola (common mola or ocean sunfish; family Molidae).

   Source: wiktionary.org