It turns out that the jellyfish were able to judge—using their frankly over-numerous 24 eyes —how far away these roots were by seeing how sharply they contrasted with the water around around them.

They captured and released two squids and a jellyfish at depths between 1,800 and 2,100 feet. The device was built, however, to withstand the deepest depths — more than 36,000 feet.