some mushrooms split alot, others which tent to cost quite a bit more dont like to split, but on them touch them alittle and make them shrink up and expose their foot and slice a pice off and that pice will move slowly away and grow another one, some like that has been stated do split way to much, one of these would be the watermellon shroom which if starting with 1, withen a year you can have hundreds of them without cutting there foot at all
lemcher, i have a mushroom almost like the one in your pic but mine is blue base area with pink/purple/ and green tips
that is one that dosent like to split it just keeps getting bigger, i am yet to cut its foot but i see 5 good spots of its foot to cut when i think its gotten big enough (its about 4" now, my friend that traded it to me has one that is 13" across)