Twenty Thousand Leagues Under the Seas by Jules Verne

The next day, the 20th of February, I awoke very late: the fatigues of the previous night had prolonged my sleep until eleven o'clock. I dressed quickly, and hastened to find the course the Nautilus was taking. The instruments showed it to be still toward the south, with a speed of twenty miles an hour and a depth of fifty fathoms.

The species of fishes here did not differ much from those already noticed. There were rays of giant size, five yards long, and endowed with great muscular strength, which enabled them to shoot above the waves; sharks of many kinds; amongst others, one fifteen feet long, with triangular sharp teeth, and whose transparency rendered it almost invisible in the water.