Are the bubble guppies nude or dressed?

i ask cuz i don' want to let my little brother watch this.if they are,those who dont know, here it is http://0.tqn.com/d/kidstvmovies/1/0/2/g/Bubble_Guppies.jpg.they girls have a top, boys tails have nothing, are the tails wih some sort of mare pants? other webs say, this counts as cartoon hidden nudity....i just want to be sure thanks