Poecilia rositae Meyer, Schneider, Radda, Wilde & Schartl 2004

Belongs to the Poecilia (M.) mexicana subgroup of shortfin mollies, which is distinguished by the following characters: longitudinal scale series 28 (rarely 27 or 29), vs. 26 to 27 in Poecilia (M.) mechthildae; predorsal scales 13-14, vs. 12-13 in Poecilia (M.) mechthildae; caudal peduncle scales 16, vs. 18 in Poecilia (M.) mexicana; pectoral rays 15, vs. 16-17 in Poecilia (M.) mechthildae; dorsal rays 10, vs. 11 in Poecilia (M.) gracilis, 7-8 in Poecilia (M.) sulphuraria; females sometimes lack rows of black spots on body sides, vs. rows of black spots present in Poecilia (M.) sulphuraria, Poecilia (M.) mexicana, vs. weakly developed Poecilia (M.) gracilis; serrae of gonopodium ray 4p massive, vs. less massive in Poecilia (M.) mexicana, Poecilia (M.) gracilis, Poecilia (M.) mechthildae and Poecilia (M.) sulphuraria; distal spine series of gonopodium ray 3 long, vs. short in Poecilia (M.) mexicana, Poecilia (M.) mechthildae and Poecilia (M.) sulphuraria; distal membranous plate absent, vs. present in Poecilia (M.) mexicana (Ref. 75917).

Dorsal soft rays (total): 10; Analsoft rays: 9; Vertebrae: 27 - 28