Deep-sea fish found living in 'virtually no oxygen' area

Marine biologists have found large schools of fishes living in depths of the Gulf of California, where there is 'virtually no oxygen', using underwater robots. Scientists conducted a series of dives using California institute MBARI's remotely operated vehicle (ROV). The ROV's instruments showed oxygen concentrations were one-tenth to one-fortieth as low as those tolerated by other low-oxygen fish.