Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Lorn
Speaker 1: Bogelbaum here. Cone snails are a group of around a
Speaker 1: thousand species of venomous, predatory marine snails that live in
Speaker 1: shallow tropical waters around the globe. Their pretty, cone shaped
Speaker 1: shells are intricately patterned and brightly colored, apprized by seashell collectors,
Speaker 1: and their venom is fascinating to biomedical researchers and science
Speaker 1: fiction writers alike, a pretty high profile for a very slow,
Speaker 1: not particularly aggressive animal that spends its days toddling after worms, fish,
Speaker 1: and other snails for dinner. For example, In the real world,
Speaker 1: their venom has been used in therapies from diabetes treatment
Speaker 1: to terminal pain management. And this is a little bit
Speaker 1: of a deep cut, but take the Jurassic Park film
Speaker 1: sequel of the Lost World. In the movie, an air
Speaker 1: gun with venom darts is used to take down Peschi dinos.
Speaker 1: The active ingredient is purported to be an enhanced venom
Speaker 1: from the cone snail species Conus propuis, ends, of which
Speaker 1: the movie says is the most powerful neurotoxin in the world.
Speaker 1: Before the article, this episode is based on how stuff
Speaker 1: work spoke with Helena Safavi, an assistant professor of biochemistry
Speaker 1: at the University of Utah who studies conesnails and their venom.
Speaker 1: She said, in the movie, the venom is described as
Speaker 1: the most powerful neurotoxin in the world that acts within
Speaker 1: one two thousandth of a second, faster than the velocity
Speaker 1: of nerve conduction. None of this is true, but nevertheless
Speaker 1: very entertaining. Conesnails are very slow animals that cannot graze
Speaker 1: on algae like their non venomous snail relatives, but also
Speaker 1: have no means of mechanical prey capture. That is to say,
Speaker 1: they can't bite or grasp like a shark or cat.
Speaker 1: And despite the lack of teeth and claws, all cone
Speaker 1: snails are impressive predators. Safavi said a when a slow
Speaker 1: animal wants to hunt other creatures, it has to evolve
Speaker 1: potent venom to be successful. Particularly those cone snails that
Speaker 1: prey on fish have to have toxins that can potently
Speaker 1: immobilize the fish prey before it swims away. One of
Speaker 1: the most remarkable things about the thousand ish species of
Speaker 1: cone snail is that there's almost no overlap in the
Speaker 1: toxins that are made by each A Safavi said, this
Speaker 1: shows how fast these toxins evolve. Even very closely related
Speaker 1: species have only around five to ten percent overlap, with
Speaker 1: each species making several hundreds of toxins. One can estimate
Speaker 1: that there are around half a million different toxins present
Speaker 1: in cone snails. Because their venoms are unique to specific species,
Speaker 1: some species deliver a very minor sting and others could
Speaker 1: kill you. A Safavi explained there are about forty known
Speaker 1: fatalities by con snails, and nearly all, if not all,
Speaker 1: were caused by a single species. Conus geographis commonly known
Speaker 1: as the geography cone. Some of the toxins in this
Speaker 1: species can cause acute respiratory failure and potentially heart failure.
Speaker 1: It's also one of the species that can inject larger
Speaker 1: quantities of venom compared to most other cone snails. Compared
Speaker 1: to snakes and even scorpions and spiders, death from cone
Speaker 1: snail stings are extremely rare. Cone snails might not have fangs,
Speaker 1: but most have a venom covered harpoon that they use
Speaker 1: to incapacitate their prey. Okay mollusks, like snails, often have
Speaker 1: a radula a type of combination tooth and tongue structure.
Speaker 1: It's often a ribbon like structure with many tiny teeth,
Speaker 1: and it helps them scrape up or cut down food.
Speaker 1: In the case of cone snails, the radula has a
Speaker 1: venom sack at its base and it's barbed at the
Speaker 1: other end it can dart out. It's some four hundred
Speaker 1: miles an hour. That's about six hundred and fifty kilometers
Speaker 1: an hour instantly incapacitating passing prey, so it doesn't really
Speaker 1: matter that conesnails are slow pokes. All the snail has
Speaker 1: to do is reel its prey into its mouth. Other
Speaker 1: cone snails, like the aforementioned geography cone creep up on
Speaker 1: sleeping fish and shoot out a cloud of chemicals, one
Speaker 1: of which is insulin that numbs their prey and sends
Speaker 1: them into a sort of hypoglycemic coma before swallowing them whole.
Speaker 1: Yet other cone snails will strike a fish but won't
Speaker 1: tether it with their harpoon. The fish will swum away,
Speaker 1: but will fall under the influence of the snail's venom
Speaker 1: pretty quickly. All the snail has to do is follow
Speaker 1: its prey and gobble it up. These are just a
Speaker 1: few con snail strategies, but with so much diversity in
Speaker 1: conesnail venom, we have a lot to learn, Safavi said.
Speaker 1: We know very little about the various ways that conesnails
Speaker 1: use their venom in the wild. A colleague of mine
Speaker 1: recently showed that some con snails use toxins that mimic
Speaker 1: mating pheromones to lure worms out of their It's really
Speaker 1: fascinating what these animals are capable of. Today's episode is
Speaker 1: based on the article the con snail is a slow
Speaker 1: but highly venomous predator on how stuffworks dot Com, written
Speaker 1: by Jesslynshields. Brain Stuff is production of iHeartRadio in partnership
Speaker 1: with HowStuffWorks dot Com and as produced by Tyler Klang.
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