Obviously commingling species has its drawbacks, but a few thigns to consider:
Is a jumping/leaping uroplatus going to kill a frog?
Is the Uro going to EAT the frog?
Can you provide an ideal environment for both? If you were to mix, say, mantellas with larger (sikorae )uros, you will need a very tall tank, heavily planted and it may be difficult to keep the water clean since the uros defecate in it like its a contest, same as a lot of other lizards (speculated to hide their scent from a potential predator..)
I am sure it COULD be done, but you really need to ask yourself if its in the best interest of the animals, or just something you would like for yourself.
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