Meet Mr. Porpoise - Ceta-Base

gether as it exists in the open sea. We therefore find
in one tank sharks swimming side by side with a school
of jacks, and a six-foot green moray coiled under the
same rock that is home to a six-inch angel fish.
Assume for a moment that we are guests for the
day at Marineland. As we approach the giant tanks,
we are astounded at the natural beauty of the place.
The tanks themselves are built along the ocean front
and to the east extends the broad expanse of the blue
Atlantic. To the west the ground rises in lump contours
of sand dunes and shell mounds, and rolls away
to the Intra-Coastal Waterway shimmering in the
bright Florida sunlight. Countless palms wave a
friendly greeting and the white of the sand dunes is
softened by cactus, yucca and seagrape.
We approach the south end of the gigantic tanks
and are directed to the main entrance. As we step
into the lower corridor, soft blue lights lead us from
porthole to porthole ; and through these windows we
gaze in awe at the fascinating, colorful undersea
world. The blue-green waters, pumped from the
ocean at the rate of five million gallons per day, are
iridescent and clear. The floor of the mammoth ocean-
arium is covered with sand, sea shells and plumes.
A seven-ton coral reef affords protection for the smaller
specimens. A 300-pound turtle lumbers lazily over
the coral reef, and great schools of shiny bumper fish
follow in his path with the hopeful expectancy of find-
ing a few scraps of food the big fellow might leave
behind. From the stern of a shipwreck, the long
sinewy shape of a shark electrifies the scene, and many
of the smaller fish scuttle for cover. A huge ray gro-
tesquely flaps his way over the sea fans while a spotted
moray suspiciously eyes his passage from a safe sanctum
in the coral.
The 200 glass portholes, averaging 18 x 24 inches,
encased in the steel tank walls, stand out like brightly
lighted stages in the semi-dark corridors. Sitting in
front of a porthole, the visitor is shielded from in-
clement weather and outside distractions as the immense
life of the ocean floor unfolds before him.
In their large size also, the oceanariums are unique.
The circular tank, the one in which the porpoises live,
is 75 feet in diameter and twelve feet deep. The other
is roughly rectangular and has a length of 100 feet,
width of 40 feet and a maximum depth of 18 feet.
Connecting the two, and serving as a quarantine for
new specimens, is the shallow receiving tank.
The design of this structure was conditioned by
the three functions it was to perform. First, to offer
the public the opportunity to observe the complexities
of life under the surface of the sea. Second, to offer
the motion picture industry the facilities for filming
underwater action against an authentic background.
Third, and most significant, to offer the scientific
world the opportunity for study and investigation into
the biological problems for which the facilities of the
institution are most adequately fitted.
To the visitors at Marine Studios, the bottle-nosed
dolphin, commonly known as porpoise in American
waters, is of greatest interest. The first view of the
large gray animals, from underwater, completely
transforms previous concepts of them.
Battleship gray with its underbody a dull white,
the porpoise embodies Nature's most streamlining
effects. Observing them through the portholes, the
visitor is amazed at the grace and speed which the
porpoise attains. The tail of the porpoise, unlike that
of any fish, beats up and down and by this perpendicu-
lar motion, the supple flow of muscular effort through-
out the entire body enables the porpoise to attain tremendous
bursts of speed. Frequently after the animal
has achieved momentum he will arch his back and
glide across the tank; and often during courtship, the
animal will barrel roll for some 20 to 30 feet.
Porpoises, of course, are primarily fish eaters, and
in coastal Florida waters they feed principally on
mullet. This readily obtained fish is fed to the porpoises
here, and each adult eats at least 20 pounds
daily.
Two opportunities, to date, have been offered to
observe the nursing and weaning of a young porpoise.
The two originally captured in March, 1938, proved
to be mother and daughter ; the young one beginning
to nurse at once. Throughout the day and night the
baby took nourishment at 15 to 30 minute intervals.
When nursing, the young porpoise holds the end
of its snout for about five seconds over the inverted
nipple, which lies hidden in a fold in the blubber. By
contraction of specialized muscles of the abdomen the
parent forces the milk, which has collected in sinuses
running lengthwise through the mammary tissue, into
the mouth of the offspring. The whole operation can
take place quickly, an obvious necessity, because young
porpoises very rarely remain submerged, at least here
in the oceanariums, for more than 30 seconds. Young
nursing manatees, on the other hand, remain underwater
for ten minutes and suckle in typical mammalian
manner.
Three weeks after capture, the young one began
grasping fish in her mouth, and after playing with the
fish for a few moments would drop it and pick up another.
Once in the fourth week the young one was
observed to swallow at least one fish.
The following day the baby was in distress. The
dull eyes and listless form bespoke complete misery.
Frequently the young porpoise vomited, and each time
the attendant parent rubbed the stomach of the little
one steadily with her snout. By late afternoon the at-
tack passed, leaving the young one completely fatigued.
18 NATURAL HISTORY, JANUARY, 1940