Cone snails have long been prized for their shells; at an auction in eighteenth-century Amsterdam, a one-inch cone snail shell sold for more than a Vermeer painting. Although this may seem outrageous, there may soon come a day when the snails have an even greater value for an entirely different reason.
Snails as Predators
More than 700 species of cone snails (members of the Conus genus) have been identified, and there are probably many others yet to be discovered. Most known species inhabit shallow ocean waters in tropical coral reef and mangrove habitats.
Although snails aren’t generally perceived as exciting creatures, cone snails challenge that stereotype with their hunting techniques. The snail wiggles a flexible tube-like proboscis to attract small fish and other prey. As a fish draws close, the snail harpoons it and injects a string of toxic peptides, paralyzing the prey and allowing the snail to devour its meal.
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Although most cone snails present little danger to humans, several of the larger snails can kill a person with their venom. Oddly enough, that same venom may also hold the key to saving lives.
Life-saving Toxins
Although cone snail research has been very limited, studies have unearthed amazing discoveries that could revolutionize the treatment of many human diseases.
Researchers have found that each species of cone snail studied contains more than 100 unique peptides (chains of amino acids), putting the estimation of total peptides for all known species at 70,000 to 140,000. These peptides bind to the receptors found on animal cell membranes and cause unique chemical reactions.
“It’s like a key fitting into a lock,” says Will Turner, Director of Global Priorities in CI’s Center for Applied Biodiversity Science. “Cone snails may be the master key.”
Most of the medical research conducted so far has investigated the potential of cone snail venom for advances in pain medication. Prialt, a drug based on a synthetic version of a cone snail peptide, was approved in 2004, and is believed to be up to 1,000 times as potent as morphine. In addition, the drug comes without the typical opiate side effects of addiction and tolerance buildup, and has proven very successful at reducing extreme pain in cancer and AIDS patients.
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Cone snail peptides have also shown potential to aid treatment of medical conditions as varied as Parkinson’s disease, epilepsy, and strokes.
Habitats on the Brink
There has never been a comprehensive assessment of cone snail abundance and their risk of extinction, and no recent studies have been conducted. Therefore, very few Conus species have been assessed under the IUCN Red List Categories and Criteria. Only four species are listed as Vulnerable on the Threatened Species List, but these listings are outdated and in need of reassessment.
Coral reef and mangrove habitats are some of the most threatened ecosystems in the world. Fifty percent of the earth’s coral reefs are at the point of collapse, and 50 percent of mangrove habitat is already destroyed. Coastal development, pollution, destructive fishing practices and direct exploitation of snails for their shells are all threats to this precious group, but the perils of climate change could pose the biggest threat. Warming temperatures and acidification in the ocean have the potential to cause serious declines in cone snail populations, and if the snails disappear, so will all their possible future benefits for human health.
Fighting for Conservation
To combat these forces, CI is working hard to protect cone snail habitats all over the world. Half of the world’s known cone snail species live in areas where CI works, such as the Coral Triangle seascape, which includes the coasts of Indonesia, the Philippines, and other prime habitats. Conservation efforts include creating and maintaining protected areas, guiding sustainable coastal development, reducing agricultural runoff, ending destructive fishing practices such as dynamite fishing, and minimizing the impact of climate change.
EXPLORE: The Coral Triangle Initiative
In addition, the Global Marine Species Assessment (GMSA), a joint CI-IUCN partnership, hopes to do a thorough assessment of cone snail species in the near future. Says Dr. Suzanne Livingstone, Programme Officer for the GMSA, “It will be extremely important to identify which cone snail species are the most threatened and where they are in the world so that we can begin protecting them.”
Saving Future Cures
For many people, it can be hard to relate to the plight of unknown species under the waves on the other side of the world. However, we are all aware of the threat of certain illnesses in our lives; many of us have seen families and friends directly impacted by diseases with few treatment options. Cone snail habitat conservation will not only help protect the species themselves, but also their potential for improving human well being in the future.
Although pharmaceutical companies spend most of their time creating synthetic materials in laboratories, most of the compounds they use are found first in the environment. “Nature’s been working for millions of years on this stuff…we are finding things that operate with entirely new chemical mechanisms we have no way of anticipating on our own,” says Turner. “We’ve just scratched the surface.”
Livingstone agrees: “We have to keep this amazing medical resource safe.”
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