You seem to have very coarse gravel in there, the Hoplo catfish won't like it at all! They need finer stuff to rummage about in.
Also its not really the best idea to start of with catfish if it is a brand-new tank, just remember not to add anything too quickly as you don't want to kill your hoplos off.
I would look into mixing some sand or finer quartz gravel in with your large gravel.
Ben