Hi nybraby,
That's cool, I've only ever had Auricularia sp. before, Those are only the fruiting bodies, and after a few days they'll go squishy and fall over. The main mycelium lives within the wood slowly breaking it down, how long that takes I'm finding out with Auricularia but the woods only been in the tank a month (it is an unplanned experiment!).
mmm..
you can buy oyster and shiitaki mushroom impregnated logs; I wonder if one could be stood in a shallow aquarium...?
phil