Travel Reference
In-Depth Information
seaward edges of New Caledonia. With members of a local French oceano-
graphic institution, ORSTOM, I would dive the magnificent outer barrier
reefs of this island after sundown, and I was routinely rewarded with sight-
ings of these beautiful animals as they concluded their long nocturnal as-
cents from their deep daytime habitats.
The New Caledonian barrier reefs parallel the Great Barrier Reef of Aus-
tralia and, like the latter, form great vertical walls extending from the warm sur-
face to cold, thousand-foot muddy bottoms. During the day, the nautiluses lurk
on the deep bottoms, out of sight and danget from the efficient shell-breaking
predators of the reefs' shallower regions. But at night, emboldened, they swim
up the reef walls to the shallows, where they feed under cover of darkness. Like
hot air balloons, they would rise upward along the reef walls, and night after
night I would wait for them, hanging weightless in hundred-foot depths, sweep-
ing the black water with my dive light to catch a glimpse back into time.
Sooner or later an isolated specimen would swim into view—they always travel
alone—and I could follow it on moonlit nights into shallower water without
lights. Nautiluses swim vigorously; they are nobody's placid snail.
My initial work was entirely concerned with how a nautilus uses its
chambered shell to achieve and then maintain neutral buoyancy in the sea.
At the time I had no research interest in the evolutionary history of this an-
imal, and for good reason:
That
story had long been worked out to virtually
every biologist's satisfaction. Just as no physicist would bother recalculating
the speed of light, nor any biologist again attempt to show that DNA is the
molecular basis of heredity, so too was working out the evolutionary history
of the extinct and extant nautiloid cephalopods, at least as understood in the
1970s, viewed as a job already done. Two giants of American paleontology
had said all there was to say on the phylogeny of the nautiloids—and of
Nau-
tilus
—in the 1950s. Or so we all thought.
Although the name
Nautilus
was applied to both fossil and living taxa
during the nineteenth and early twentieth centuries, by the 1950s the name
was restricted to the living species, even though it was recognized that many
fossil forms were morphologically similar to the living species. This change
in concept was brought about largely through the landmark work of A. K.
