The tire-size opah, which can weigh up to 200 pounds, thrives in cold ocean depths by keeping its blood warm, making it the first fish ever discovered to generate its own body heat. It does so in a bizarre way.
The tire-size opah, which can weigh up to 200 pounds, thrives in cold ocean depths by keeping its blood warm, making it the first fish ever discovered to generate its own body heat. It does so in a bizarre way.