Hawaiian Seashells

The triton shell has long been used as a trumpet by the Polynesians. My grandmother used this particular triton to call the workers in for lunch from the mud, humidity and backbreaking work of tending to the Taro paddies. When I found this triton, my step grandmother had filled it with floral clay and plastic flowers and thus it sat in a dark corner, dusty, un-loved and unappreciated. Luckily, even as was a young child, I was fascinated by Hawaiian seashells and, as you might imagine, a little begging with Grandpa soon freed this shell from its ignominous fate.

As a child, I used to sit high atop the hills overlooking Palolo Valley and, as I blew that triton, it's sound echoing all across the valley, I thought of what it might have been like back in the days of my grandma, back when shells like this still washed up on the beach.  While I no longer torture my neighbors with the echoing sound of its trumpeting (not too often anyhow), this shell has come to symbolize a link back to my true Grandmother and to the life that she lived in taro fields of old Hanalei.

For the early Hawaiians, seashells were a source of food (for example, opihi, pipipi and other wave zone molluscs were and are still commonly eaten), of adornment (cowries or "leho" in particular were strung in leis), of communication (tritons, conches), of lures (for squid) and as a material for fish hooks and weapons. Shells were a central part of Hawaiian life.

However, as it turns out, all shells, including the Triton also play a unique role in the Hawaiian ecosystem. For example, the triton is one of the only predators that keeps the population of crown of thorns starfish under control. When the Triton was over-collected back in the 70's, the crown of thorns starfish population reached unprecedented highs, causing significant damage to the reef, and requiring mass collection of crown of thorns starfish by divers to save the reef. The Triton is now protected by Hawaiian law, prohibiting the collection and sale of these magnificent shells.

Hawaii's shells have evolved across thousands of years into unique variants of their Indo-Pacific relatives, each with its own ecological niche. Some achieve significantly larger size; others are just color variants. Some of the variation in color or size may be due to slightly different diets, perhaps a different sponge or seaweed species than their Indo-Pacific cousins. Still other shells have speciated into unique and wonderful creatures found nowhere else in the world.

Each of these species occupies a unique niche or role in the Hawaiian ecosystem. We discussed the triton above. Other shells, such as the tiny Vexilla prey upon sea urchins. The reef-flat cones such as the Rat Cones and Soldier Cones typically prey on worms, bristleworms included [author's note: if you've ever been stung by a bristleworm, you'd remember it]. The Beck's Cowrie is only found in the bases of slow growing black coral trees. Thus, when you remove a particular species, either the shell or the host that it depends upon (Black coral for instance), the ecological cycle is broken, often exposing the environment to uncontrolled effects within that niche. These effects can be localized or, as with the triton, far ranging.

While the Hawaiian's used shells extensively and, arguably, Hawaii's residents still do to this day, the greatly enlarged population in the islands, the silt from pervasive human habitation and deforestation and the millions of visitors to Hawaii are exerting unprecedented pressure on Hawaii's fragile marine ecosystems. The advent of scuba and related underwater technologies now gives man unprecedented access to the ocean in a way the Hawaiians never did. As a young child, I thought that the bounty of Hawaii's seas was endless and would last forever, no matter what we did. The reefs were covered with cones, cowries, lobster and coral banded shrimp. However, I have watched the seashells grow more and more scarce where they were once bountiful and can only wonder about the impact on the niches that they occupy. Therefore, if you are thinking about collecting Hawaii's shells, try doing it with a camera. Nothing is killed and you can share with your friends. If you must collect, there are often fairly nice dead specimens washed up on the shore, particulary in areas where coral rubble accumulates. And, if you still cannot resist, please do so with restraint.

On this web page, I have tried to capture a few of Hawaii's shells in photograph in the hopes of preserving and sharing their beauty for those of you that cannot visit Hawaii and see them in person and for those of you that remember what Hawaii once was. That being said, it is a bit tough finding photos of Hawaiian shells so, if you have photos you can share, especially of live Hawaiian seashells, please send them along to be added into later updates.

Okay, on with the story. As a child, my favorite genera was always the Cowrie, known for it's bright colors, smooth, worry-free surface and wonderful sheen. In Hawaii, the general name for Cowries is Leho. In old Hawaii, the natives strung the leho on cord and made shell leis that were worn around the neck for adornment, similar to the ones sold today in convenience stores across the state (typically from the Philippines but that is another story again).

Many cowries feed on algae, generally at night. In the day, they may be found hiding underneath coral rubble. Other cowries are found in association with specific corals or sponges upon which they feed. The amazing sheen of their shells is maintained by the animal through a thin membrane or mantle which continues to build the shell throughout the the life of the animal and, in most cases, also hides the animal from predators.

On the reef, the cowrie is normally covered by its mantle, enabling it to blend in with the surrounding algae, rocks and coral. The easiest way to spot a cowrie is to look for the glint of reflection off of the small uncovered area between the two sides of the mantle.

There are many other fascinating shells in Hawaii that fill a broad variety of ecological niches. For example, the Cones are largely carnivorous, feeding on worms, shells, fish and even other cones. On the flip side, the conchs are largely herbivorous, being the cows of the sea, as they patiently graze on algae. A few, such as the marbled top snail (2mm), are so small they are best looked at under a magnifying glass and can often be found as you sift through beach sand.

The cones are carnivores, each capable of delivering a venonous sting that is used to paralyze its prey. The cone then typically envelopes the prey with its proboscis and digests it, discarding the remains. Conus marmoreous is one of three Hawaiian cones notedly poisonous to humans (although all are capable of stinging). This cone preys upon other cone shells. The other two poisonous Hawaiian cones, Conus textile and Conus striatus prey upon other shells and sand gobies (and other small sand-dwelling fish) respectively.

Many of the more common shells also found their way into the Hawaiian diet. The Hawaiian Limpet or Opihi is a favorite to this day and is eaten raw, sometimes right off the rock, or mixed with seaweed and spices (Opihi Limu Poki). The following are a small sample of the multitude of Hawaiian shells.

I would like to extend my thanks to Stephen Quirk and Betsy Harrison for the information provided in the book Hawaiian Seashells, to Mike Severns for the more exhaustive compilation in the newer text, Hawaiian Seashells and other contributors to this page. My apologies for the occasionally fuzzy photos, most taken one Saturday afternoon spent with the digicam under natural light. If you would like to contribute to additional photos or information to this page, please send me your comments, photos, etc...

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