`But those animals that do live at depth will clearly need some special adaptations, says Dr Jamieson.

"They'd have to do something clever inside their cells. If you imagine a cell is like a balloon - it's going to want to collapse under pressure. So, it will need some smart biochemistry to make sure it retains that sphere," the scientist explained.`

I don't understand how octopi would need special cellular adaptations for living at t those depths. So long as their cells do not require air cavities (fairly certain they don't), I can't see what the issue could be. Differential pressure can cause problems, but there's no delta-p when your cells are equally incompressible solids and liquids.

I hope that I'm wrong though and that this scientist isn't as mistaken as they sound.