They went in groups of five or six, hunting in packs like wolves over the countryside; moreover, they're just as voracious as dogfish, if I can believe a certain Copenhagen professor who says that from one dolphin's stomach, he removed thirteen porpoises and fifteen seals.
True, it was a killer whale, belonging to the biggest known species, whose length sometimes exceeds twenty–four feet.
The family Delphinia numbers ten genera, and the dolphins I saw were akin to the genus Delphinorhynchus, remarkable for an extremely narrow muzzle four times as long as the cranium.
Measuring three meters, their bodies were black on top, underneath a pinkish white strewn with small, very scattered spots.
From these seas I'll also mention some unusual specimens of croakers, fish from the order Acanthopterygia, family Scienidea.
Some authors—more artistic than scientific—claim that these fish are melodious singers, that their voices in unison put on concerts unmatched by human choristers.
I don't say nay, but to my regret these croakers didn't serenade us as we passed.
Finally, to conclude, Conseil classified a large number of flying fish.
Nothing could have made a more unusual sight than the marvelous timing with which dolphins hunt these fish.
Whatever the range of its flight, however evasive its trajectory (even up and over the Nautilus), the hapless flying fish always found a dolphin to welcome it with open mouth.
These were either flying gurnards or kitelike sea robins, whose lips glowed in the dark, at night scrawling fiery streaks in the air before plunging into the murky waters like so many shooting stars.
Our navigating continued under these conditions until March 13.
That day the Nautilus was put to work in some depth–sounding experiments that fascinated me deeply.
By then we had fared nearly 13,000 leagues from our starting point in the Pacific high seas.
Our position fix placed us in latitude 45° 37' south and longitude 37° 53' west.
These were the same waterways where Captain Denham, aboard the Herald, payed out 14,000 meters of sounding line without finding bottom.
It was here too that Lieutenant Parker, aboard the American frigate Congress, was unable to reach the underwater soil at 15,149 meters.
Captain Nemo decided to take his Nautilus down to the lowest depths in order to double–check these different soundings.
I got ready to record the results of this experiment.
The panels in the lounge opened, and maneuvers began for reaching those strata so prodigiously far removed.
It was apparently considered out of the question to dive by filling the ballast tanks.
Perhaps they wouldn't sufficiently increase the Nautilus's specific gravity.
Moreover, in order to come back up, it would be necessary to expel the excess water, and our pumps might not have been strong enough to overcome the outside pressure.
Captain Nemo decided to make for the ocean floor by submerging on an appropriately gradual diagonal with the help of his side fins, which were set at a 45° angle to the Nautilus's waterline.
Then the propeller was brought to its maximum speed, and its four blades churned the waves with indescribable violence.
Under this powerful thrust the Nautilus's hull quivered like a resonating chord, and the ship sank steadily under the waters.
Stationed in the lounge, the captain and I watched the needle swerving swiftly over the pressure gauge.
Soon we had gone below the livable zone where most fish reside.
Some of these animals can thrive only at the surface of seas or rivers, but a minority can dwell at fairly great depths.
Among the latter I observed a species of dogfish called the cow shark that's equipped with six respiratory slits, the telescope fish with its enormous eyes, the armored gurnard with gray thoracic fins plus black pectoral fins and a breastplate protected by pale red slabs of bone, then finally the grenadier, living at a depth of 1,200 meters, by that point tolerating a pressure of 120 atmospheres.
I asked Captain Nemo if he had observed any fish at more considerable depths.
"Fish?
Rarely!" he answered me.
"But given the current state of marine science, who are we to presume, what do we really know of these depths?"
"Just this, Captain.
In going toward the ocean's lower strata, we know that vegetable life disappears more quickly than animal life.
We know that moving creatures can still be encountered where water plants no longer grow.
We know that oysters and pilgrim scallops live in 2,000 meters of water, and that Admiral McClintock, England's hero of the polar seas, pulled in a live sea star from a depth of 2,500 meters.
We know that the crew of the Royal Navy's Bulldog fished up a starfish from 2,620 fathoms, hence from a depth of more than one vertical league.
Would you still say, Captain Nemo, that we really know nothing?"
"No, Professor," the captain replied,
"I wouldn't be so discourteous.
Yet I'll ask you to explain how these creatures can live at such depths?"
"I explain it on two grounds," I replied.
"In the first place, because vertical currents, which are caused by differences in the water's salinity and density, can produce enough motion to sustain the rudimentary lifestyles of sea lilies and starfish."
"True," the captain put in.
"In the second place, because oxygen is the basis of life, and we know that the amount of oxygen dissolved in salt water increases rather than decreases with depth, that the pressure in these lower strata helps to concentrate their oxygen content."
"Oho!
We know that, do we?"
Captain Nemo replied in a tone of mild surprise.