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Friday, July 6, 2001

Marine snails hold value beyond their pretty shells

Last week, several of my friends and family members went on a daylong outing to some North Shore beaches.  They snorkeled at Sharkís Cove, admired the turtles of Laniakea and combed the white sand beaches.

When they got home, one child wanted to show me what he found.  From his beach bag, he pulled a rigid eyeglass case.  I knelt down, wondering what marine treasure the boy had in there.  But he had hundreds of marine treasures.  The case was full of snail shells.

We poked through the collection together, carefully examining the tiny shells and discussing the animals that once lived inside.  But when the boy started asking me the names of the snails, the conversation came to an end.  Beyond cones and cowries, I donít know what to call most Hawaiian snails.

A week later, I found my own treasure: a book called Hawaiian Seashells by Mike Severns (Island Heritage).  Itís the first Hawaii-specific book Iíve seen where a person has a good chance of finding a shell in question and then remembering its name.  The pictures are clear, and in addition to scientific names, Severns mercifully offers common names.

Take wart turbans for instance.  These shells, about an eighth of an inch wide, are common in beach sand.  Once at a cove near Kaena Point, I spent a whole afternoon examining these and other little shells that make up much of the sand there.  I had no idea what wart turbans were called until I found this book.  Now Iíll never forget their name.  Wart turban sticks in my mind far better than Leptothyra verruca.

Other choice names from Severnsí book are wine-mouthed frog shell, catís tongue oyster and love harp.

There is one name I donít like much, however, and thatís the word seashell.  Staff members at aquariums throughout the country, including the Waikiki Aquarium, encourage using the word snail instead of shell or seashell and I heartily concur.  The term snail conjures up an entirely different image than the term seashell.  Just saying the word snail reminds us that shells are the homes of living animals and not simply seaside trinkets. 

Which brings up the subject of collecting.  In his book, Severns tell us that the shells we find are often the homes of living creatures, whether occupied by the original owner or a hermit crab.  ďTherefore,Ē he writes, ďthe collecting of living shells should be avoided.Ē

Severnsí message is OK, but hereís mine: Donít do it.  In this era of accelerated, human-caused extinctions, and depleted marine resources, killing snails for their shells is wrong.  Itís no more justified than killing elephants for their tusks or albatrosses for their feathers.  In my family, we donít even keep empty shells.  We admire them for a while, then give them back to the ocean. 

Snail shells are marvelous things but the living animals inside them are even more so.  Take the herbivorous (vegetarian) snails called strombids.  When a predator cone snail approaches, strombids can leap an amazing 3 feet to get away.  The strombid does this by catapulting off its strong, pointed foot and sharp operculum (the round plate sealing the shell shut).

We donít usually think of marine snails as active animals but they dig, hop, secrete acid, bore into other snails and pry open clamshells.  Some even eat fish; others eat Portuguese man-of-wars.

Iíve always admired Hawaiiís snails and their lovely shell homes.  With this new book, I may now even remember some of their names.





Marine biologist Susan Scott writes the newspaper column, "Ocean Watch",
for the Honolulu Star-Bulletin,