One Shell Builds a Raft to Live Upon
Scallop Can Jump Out of a Boat—Doings of Shells Fill a Whole Book
by Hyatt Verrill
Daily Boston
Globe; Nov 4, 1936, pg. 29.
Researched by Alan Schenker; digitized by Doug Frizzle, Mar. 2012.
Did you know that some "shells". the
things most of us call shellfish, are good athletes?
That some
of them build rafts and go
a-sailing?
That others
are dangerous beasts of prey, killing and devouring other
shells? That some can even kill men?
That some
can spin a golden thread from which
was once made a cloth reserved for kings?
These and many other strange and fascinating bits of information
about shellfish are contained in "Strange Sea Shells and Their
Stories," by Hyatt Verrill, just published by L. C. Page & Co of Boston.
Mr. Verrill, who is the author of "The Incas' Treasure House"
and other books, recounts many
truths literally stranger than fiction.
Take first the raft-building shell.
"It is," writes Mr.
Verrill, "a little, coiled shell an inch or two in diameter and much like
a snail in form, but of a beautiful lilac-purple color. As a rule only an
occasional shell is washed up on our beaches and even if you should be lucky
enough to find windrows of the
shells you might examine every one without finding a living individual, for
this shell lives far out at sea and, instead of crawling about upon the bottom
of the ocean, it spends its life
floating or sailing about like a little ship.
Floating on Bubbles
"Indeed, the ianthina is one of the
strangest and most interesting of all shells and one of its strangest habits is
that it actually builds a boat, or rather
a raft. Like other univalves or
single shell molluscs, the ianthina
breaths through a siphon or tubular probosis, but it differs from all others
in using its siphon for another
purpose as well as for drawing water into its gills, for with its probosis it
sucks in the air with which it forms
its raft.
"When the shell decides to turn sailor and go cruising
about the ocean it exudes a little
sticky mucus or slime. Then it draws air into its siphon and permits the bubbles to escape beneath the
mucus, to which they adhere. In a
way the process is very much like
blowing bubbles by placing a tube or pipe beneath the
surface of soapy water and blowing air through the
tube or pipe stem.
"And as every child has
done this, you know how the masses
of pearly bubbles rise and cling together
at the surface of the water, although as there
is nothing to hold the bubbles in
place they soon collapse or burst
But when the shell blows its
bubbles, they are confined by the mucus, which soon hardens and forms a tough
strong float supported upon a layer of air bubbles.
"In a way it is exactly
like a raft with pontoons, but the ianthina's
raft has one great advantage over any boat built by man, for if one of the air bubble pontoons breaks or becomes loose and drifts away or leaks, the shell instantly replaces it with another bubble. Moreover, the
shell can enlarge its raft at will.
Takes Whole Family For a Sail
"When the weather
is calm and no danger threatens, the
shell floats about hanging to one end of its raft with its head and tentacles
projecting from its purple house;
but if the sea becomes too rough or if something
frightens the shell-sailor it shrinks
back into its cabin and hides beneath the
bottom of its raft until the storm is over or the
danger has passed."
Mr. Verrill continues
describing how this queer shellfish carries its whole family along, with the eggs fastened to the
underside of the raft. When the eggs hatch the
baby molluscs cling for a few days to the
raft or swim about; but when they
grow older and their shells begin to
form they start building their own rafts. Like other
ship owners, the ianthina sometimes carries a passenger in the shape of a tiny shrimp-like crustacean, found
only on the raft.
The ianthina is one of the savage shellfish. When it comes within reach of a jelly-fish, the ianthina, which Mr. Verrill calls the "purple pirate," comes alongside, seizing its prey with its probosis
and proceeds to tear it apart. The little ianthina, only two inches in
diameter, will kill and eat a six-inch stinging jellyfish. Shellfish can be
dangerous even to human beings and Mr. Verrill describes some of them.
There is, for example, the
Cloth-of-Gold Cone, which carries a sharp curved blade in its snout which can
be thrust in and out like a cat's claw. At the
base of this natural dagger is a sack from
which a stream of deadly poison can be ejected along the
grooves in the dagger.
Dangerous as a Snake
These Cloth-of-Gold Cones are
as dangerous as rattlesnakes and there
are plenty of authentic cases, says
Mr. Verrill, of men dying from the stab. Often the
only result is severe sickness.
The giant clams of the Pacific have killed men, too. Any unlucky diver whose hand or leg is caught
in the vise-like grip of the huge shells will drown unless help comes quickly.
As to shellfish athletes, how
about scallops? They not only swim well by opening and closing the shells, forcing the
water out with sufficient force to move them,
but by the same means they can make a jump so long that they frequently leap out of a boat and escape.
Then there
are the conches of the warm seas. When frightened they can leap like a pole vaulter, the claw-like "door" of the shell serving as the
"pole" when it is dug into the
sand. Incidentally, conches like a good many other
shellfish have eyes and can see their
enemies coming.
In the
Mediterranean there
is the "Spanish oyster" or
pinna. It spins a golden thread through a sieve-like opening, forming thousands
of fine cobweb strands, tangled and interlocked like fine steel wool. From the
"Spanish oysters" thread can be made a cloth of a beautiful golden
tint, finer than the finest silk and
so delicate and soft that a pair of gloves made from
it can be placed in the shell of a
walnut. Once this was reserved for royalty and today it is very rare and
costly. Other species of pinna
produce threads of other colors.
Shells have often been used
for money. In the South
Seas the handsome cowry shells were recognized coinage and many
African tribes used the same legal
tender. In the days when sailing
ships traded among the Pacific
islands, says Mr. Verrill, their
captains and owners made fortunes by buying cowries from
the islanders and trading them in Africa. The
rate of "exchange" was favorable.
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