On 16 February, when I found dad in the cave with fry, I tried dumping (repeatedly)... and then shaking... the cave to drop the fry into a fry basket. Only after no fry fell out did I then see the female trapped inside. And yet, in spite of all the shaking, she didn't leave the cave (or he didn't let her).
I didn't want to let the fry get loose in the tank, so I put the whole cave in the fry basket, with both parents inside. But two days later the adults were still inside, the male was quivering his tail like they do, and the babies were still hiding deep in the cave, unwilling and perhaps unable to leave the cave because mom and dad were blocking them. I tried shaking the cave again, and still no fry fell out. And the female stayed inside.
After those two days, I surrendered the idea of getting the fry out, so I removed the cave from the fry basket and put it back in the tank in its original position... and still, with all this commotion, the female didn't leave.
Finally, after 5 days of trapping (that I knew of - who knows how long she was in the cave before I found her on the day of the other photo), she laid new eggs and this morning dad is sitting on a new pile of fresh eggs. YAY!
But there is no sign of the fry. Either they are all loose in the tank, or they are still hiding in the cave, now behind the eggs.
No matter, it's a great day.
Cheers, Eric