I sorely regret googling this.Pearlfish. Its anal symbiosis with the sea cucumber is among the most miraculous wonders of the animal kingdom. I don't know if anyone has kept a pearlfish, so I know nothing of their care requirements or availability. But it would be nice to have a display tank dedicated to the pearlfish/sea cucumber co-evolutionary relationship. Besides, given the karmic downslide I'm on, it would be perhaps prudent to have some direct observation of what awaits me in the next life.