The black shark Labeo chrysophekadion,FKSM do you know just how big your cute little shark is going to get? I hope you have a very big tank for it to go into.They can grow to 24" and become more and more aggresive as they grow,they also lose their attractive black colouring and turn a washed out slate grey,i have one that is 8" that i really wish i hadnt bought but dont have the heart to get rid of i will eventually donate it to a public aquarium once it has a little more size about it.
If its cave is too small for it then just remove the cave and replace it with a selection of better sized caves so that the shark can pick which one it likes best,you can remove the spare once it has settled.