The Deadly Venom of Cone Snails

Snails, or gastropods , are an immensely diverse group. Estimates for the number of species range from 65,000 to 80,000! Cone snails, within the genus Conus represent 900 of these gastropod species. Cone snails are one of the fiercest competitors within the intertidal zone, largely due to their venom. There are three ways in which cone snails use their venom.

The net engulfment method

Net engulfment occurs in two species of cone snails, both of which are closely related. These two snails differ from other cone snails as they are the largest fish-eating cone snails. Additionally, they are surprisingly light and agile for their size, allowing them to dart after much faster-moving fish. Whoever said a “snail’s pace” was slow never met a cone snail.

Cone snails have a large, funnel-shaped organ known as a rostrum . Think of it as an oversized, fleshy mouth that can extend way out of the cone snail’s body. The cone snail places itself under an unsuspecting fish. It then extends the rostrum, engulfing the fish completely. The rostrum acts like a net. Once the fish is secure, it slowly deploys the venom, paralyzing the fish.

The strike and stalk method

So far, the “strike and stalk” strategy has only been observed in one species of cone snail. This strategy also requires cone snails to be incredibly quick. Cone snails possess a long harpoon-like structure, which is a modified tongue. The tongue can be several times longer than the snail itself. It has no barbs, but a small tube to inject venom. Once the prey has been identified, the cone snail waits for its moment and strikes! As the venom takes its time to act, the cone snail stealthily follows (stalks) its prey. Once completely immobile, it extends the rostrum and enjoys its meal.

The harpoon attack

The harpoon is probably the most well-known and common predation strategy of the cone snail, being used in dozens of species. The harpoon-like tongue is barbed at the end. When the tongue shoots out at a fish, the tip remains within the fish’s body. The harpoon is then reeled back in, and the cone snail engulfs the catch with its rostrum.

A cone snail harpoon can be deployed incredibly quickly. It can reach a peak speed of 56 miles per hour (90 kmph)! The acceleration is 400,000 meters per second squared, about the same acceleration as a bullet fired from a gun. This is even more impressive as the harpoon is usually deployed in water, which slows motion down.

As deadly as the cone snail is, new research suggests it can be beneficial, too. The venom is being researched as non-addictive painkiller and anesthetic. It might even help people with diabetes. New wonders are still being discovered, even on fringing shores close to human populations. Who knows what the ocean holds!

Flesch Kincaid Grade Level: 6.5

Flesch Kincaid Reading Ease: 72.1