I would say balloom mollys are the smallest, they only get between 2 and a half and 3inchs max, standard mollys reach between 3 and 4inchs and sailfin mollys can get between 4 and 5inchs max- any molly can be dalmation, its just a color variation . You don't have any space though left in your tank for mollys unless you are thinking of getting a new tank- you could fit about 3 balloon mollys in a 10gal but only 2standard mollys of same gender in a 10gal.