WEBVTT - Are Hammerhead Worms Really Dangerous?

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<v Speaker 1>Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren

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<v Speaker 1>Vogelbaum here. Every now and again, Americans get word that

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<v Speaker 1>a new killer creature is invading our country. Killer bees,

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<v Speaker 1>murder hornets, fire ants, and on and on. It keeps

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<v Speaker 1>the news. Spicy hammerhead flat worms commonly called hammerhead worms,

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<v Speaker 1>occasionally make their way into the rotation because they're not

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<v Speaker 1>native to many places in the world, and they're toxic

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<v Speaker 1>and aggressive predators, and they're slimy and leech like with

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<v Speaker 1>anvil shaped heads. But unlike many other terrestrial worms, they

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<v Speaker 1>can grow to around eighteen inches or forty five centimeters long.

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<v Speaker 1>People sometimes mistake them for snakes, but hammerhead worms aren't

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<v Speaker 1>anything to get too fussed about. They're not a new

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<v Speaker 1>thing in the US nor in most other places in

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<v Speaker 1>the world. They've been common residents of American gardens the

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<v Speaker 1>early nineteen hundreds. These predatory planarians are native to tropical

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<v Speaker 1>and subtropical regions of the globe. Over the course of

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<v Speaker 1>the past couple hundred years, a global commerce has helped

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<v Speaker 1>the hammerhead worm wriggle its way into most suitable habitats

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<v Speaker 1>in the world, and there are a lot of suitably warm,

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<v Speaker 1>wet habitats out there, though you're unlikely to find them

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<v Speaker 1>in a desert or at the top of a mountain.

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<v Speaker 1>For the article, this episode is based on how Stuff Works.

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<v Speaker 1>Spoke with Matt Bertone, an entomologist at NC State University.

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<v Speaker 1>He said, as some have been here for over a

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<v Speaker 1>hundred years, so they're well established. They easily hide among

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<v Speaker 1>objects and in soil where there's moisture, so moving any

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<v Speaker 1>type of container or plants around the world has allowed

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<v Speaker 1>them to colonize new areas. Thus, they are highly invasive

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<v Speaker 1>and frequently show up in new regions. Hammerhead worms are

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<v Speaker 1>carnivorous and often cannibalistic. They're sensitive to light and our

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<v Speaker 1>active mostly at night, feeding on a variety of small,

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<v Speaker 1>soft bodied animals snails, slugs, and earthworms mostly, though they

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<v Speaker 1>occasionally feed on other small invertebrates like insects. Bertone explained

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<v Speaker 1>they wrap around their prey with sticky mucus and use

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<v Speaker 1>a mouth located on their belly in the middle of

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<v Speaker 1>the body to consume prey. They use special enzymes to

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<v Speaker 1>digest the prey outside of their body after the digestive

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<v Speaker 1>juices have done their business effectively turning prey into a

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<v Speaker 1>puddle of goo. The hammerhead worm sucks its victim in

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<v Speaker 1>with the help of a bunch of tiny hair like

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<v Speaker 1>structures on its underside, called cilia. The cilia also helped

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<v Speaker 1>the worms in locomotion, acting like hundreds of microscopic legs

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<v Speaker 1>to pull them along on a thin film of slime

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<v Speaker 1>that the worms excrete. The life cycles of flatworms are

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<v Speaker 1>complex and differ from species to species. Hammerhead worms are hermaphroditic.

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<v Speaker 1>They have both male and female productive organs, and can

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<v Speaker 1>reproduce either sexually or asexually, though asexual reproduction is more common.

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<v Speaker 1>For instance, a species native to Southeast Asia but common

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<v Speaker 1>worldwide typically reproduce by fission, especially when they're outside their

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<v Speaker 1>native range. In this process, a small portion of the

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<v Speaker 1>body near the tail pinches off and becomes a new worm,

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<v Speaker 1>a clone of its parent. Another species, Eggs are produced

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<v Speaker 1>when they mate with other worms, self fertilize or clone themselves.

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<v Speaker 1>But why are they considered so hazardous? Bertone explained. Species

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<v Speaker 1>of hammerhead flatworms are the only known terrestrial invertebrates that

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<v Speaker 1>produce to trototoxin, the poison that makes pufferfish deadly. However,

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<v Speaker 1>they do so only in small amounts and are not

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<v Speaker 1>dangerous to humans in less eaten in large numbers. Thus

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<v Speaker 1>their danger is often overexaggerated. Hammerhead worms do pose a

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<v Speaker 1>real threat to earthwork populations, however. For instance, researchers are

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<v Speaker 1>concerned about the populations in France, where the presence of

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<v Speaker 1>hammerhead worms had somehow gone undetected by scientists and gardeners

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<v Speaker 1>alike for more than twenty years. The concern is that

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<v Speaker 1>hammerhead worms, which don't aerrate and fertilize the soil the

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<v Speaker 1>way that earthworms do, have been eating earthworms and other

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<v Speaker 1>helpful soil fauna in scarcity. Today's episode is based on

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<v Speaker 1>the article hammerhead worms are toxic and invasive, But are

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<v Speaker 1>they dangerous? On holstaffworks dot com written by Jesslyin Shields.

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<v Speaker 1>Brainstuff is production of by Heart Radio in partnership withhustaffworks

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<v Speaker 1>dot com, and it is produced by Tyler Klang. Four

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