Cant capture monsters past floor 1?

Well im on sealed space on floor one and currently at the lava on floor 2 but after i unlocked floor 2 a while ago, i exepected to be catching new monsters...so we can only catch on floor one or is there a req or something

[Shadehawk]

only floor one, there are several 'caves' on floor 3 that you can catch in but that is it.

but you can also create monsters by synthesis.