Sunday, 25 March 2012

One Shell Builds a Raft to Live Upon


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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As an armed forces brat, we lived in Rockcliff (Ottawa), Namao (Edmonton), Southport (Portage La Prairie), Manitoba, and Dad retired to St. Margaret's Bay, NS.
Working with the Federal Govenment for 25 years, Canadian Hydrographic Service, mostly. Now married to Gail Kelly, with two grown children, Luke and Denyse. Retired to my woodlot at Stillwater Lake, NS, on the rainy days I study the life and work of A. Hyatt Verrill 1871-1954.