So this is pretty interesting! I have a question. Is the depth of the water in your pictures how they are kept constantly, where the catfish are not completely submerged in water? Or was your visit just during a time they were changing the water, so the water level was low during your visit?

It looks like water lines along the side of the tank, so I am guessing that all of these images are from water changes.

So you say they raise them until 120 months, or 10 years? That's a pretty long time investment in raising each fish to maturity.