Cone Snail

CONE SNAILS

Kingdom: Animalia

Phylum: Mollusca

Class: Gastropoda

Superfamily: Conoidea

Family: Conidae

Genus: Conus

Species: Conus geographus

General

There are about 800 different species of cone snails found throughout seas and oceans across the world. They are endemic to more temperate environments such as the coast of South Africa, the Mediterranean, and Southern California, but can live in most all marine environments. The different species display a wide variety of colors and patterns on their shells, but all have whorled shells with spires at the end, that can vary in size. Even members of the same species can look completely different. Because of this, it is sometimes hard to give the array of snails an exact taxonomic assignment.

C. geographus has a thin shell that is broad and cylindrical. They are typically 4 to 6 inches in length. They have a marble look to them typically with light and dark browns mixed with white. The inside is normally white or light pink. Their shell is valuable to poachers.

Reproduction

Cone snail reproduction has not been widely studied, but we do know that most species have separate sexes and internal fertilization. The snails will lay egg capsules that attaches to a substrate, and contains varying amounts of eggs. There are two hatchling types that have been found; the first called veligers which are free-swimming larvae, and the second called veliconcha which are essentially baby snails.

Feeding Habits

Cone snails can be categorized into groups based on what they eat. There are fish-eaters, mollusk/snail-eaters, and worm-eaters. They are mostly nocturnal, and along with being some of the most brilliantly colored, they are also among the most venomous creatures in the world. Although they are slow-moving, they are some of the fastest known hunters, and their attacks are incredibly quick, on average lasting only milliseconds. Using stealth and venom, they can attack their prey to capture and kill them. The venom chemical makeups vary from species to species, and are used to catch small fish and other prey. The Conus geographus among other species has venom potent enough to be fatal to humans, and are considered to be one of the most venomous animal in the world. They should be handled with extreme caution as there is no antivenom.

Studies

As was previously mentioned, cone snails are extremely venomous. Interestingly enough, the snails are heavily collected to be used in scientific studies of the potential uses of their venom in medicine, particularly pain-killing drugs. Research has found that there can be therapeutic potential in the venom as well as be 10,000 times more potent than morphine.

The paper I found and researched was about using cone snail from Conus geographus venom-derived NMDA receptor antagonists conantokins G and T, to see how they effected the pain from nerve injury and inflammation-induced injury in mice. The study looked at two phases of pain, and found how each conantokin reduced the pain, or if it did at all. The first phase of pain comes from your primary afferent fibers in your nervous system, and the study did not find any conclusive results that the conantokins did anything to reduce the pain. As for the second phase, the pain comes from the injury from the peripheral tissue and inflammation. The study did find positive results from both conG and conT in this phase. They found that both had relatively long-lasting effects on reducing pain (by monitoring the behaviors of the mice) when it was injected in small doses.

QUESTIONS?

References

“Geography Cone.” National Geographic, 4 June 2017, www.nationalgeographic.com/animals/invertebrates/g/geography-cone/.

Malmberg, Annika B, et al. “Powerful Antinociceptive Effects of the Cone Snail Venom-Derived Subtype-Selective NMDA Receptor Antagonists Conantokins G and T.” Pain, vol. 101, no. 1, 2003, pp. 109–116., doi:10.1016/s0304-3959(02)00303-2.

Tucker, J.K., et al. “Catalogue of Recent and Fossil Conus.” The Conus Biodiversity Website, biology.burke.washington.edu/conus/catalogue/index.php.