i have a female red terror about 6-7 inches and so i love the fish so i go to buy some more and got 4. there all around 3-4 inches. they all have black on there dorsal fin and blue speckling around there tail fin. the black points toward female but the blue speckling by the tail says male at least in larger species. can smaller females show blue spots by tail and visa versa with male showing black on dorsal fin?