The Phantom Redtail catfish is an amelanistic color morph characterized by the lack of pigments called melanins. This means they lack the normal black color a regular morph would have. These will never turn black or have the gray shading on top, will always be full white The redtail catfish, Phractocephalus hemioliopterus, is a pimelodid catfish. In Venezuela, it is known as cajaro, and in Brazil, it is known as pirarara, stemming from the Tupi language words pirá and arara.