In a fish, gold skin color (G) is dominant to black skin color (g) and split tail fin (S) is dominant to single tail fin (s). Breeding between two fish of unknown genotypes results in the following phenotypic ratios in the progeny: 1/4 gold, split tail fin; 1/4 gold, single tail fin; 1/4 black, split tail fin, and 1/4 black, single tail fin. What are the genotypes of the two fish used for breeding?