Toxic and Invasive Hammerhead Flatworm Species Discovered in Texas

A highly invasive species of hammerhead flatworms known for their toxic threat to humans has been discovered in Texas.

Director of Research and Education/Outreach at the Texas Invasive Species Institute Ashley Morgan-Olvera confirmed with Newsweek that the invasive hammerhead flatworm has been found throughout the state. Although she noted the species, known scientifically as Bipalium kewense, is most commonly found in the southeastern region of Texas, it has since been traced to other areas of the state like Dallas.

"Our Institute started tracking this flatworm in 2017 when we started receiving occasional reports around Houston, and some citizens provided anecdotal evidence of 'growing up with them' around Beaumont and east Texas—so we estimate it arrived in [Texas] in the 1980s but there is not much historical data," she told Newsweek.

"What we have learned for Texas in the past week is Bipalium kewense is well-established in natural habitats throughout east, north, central and coastal regions of the state."

According to the Texas Invasive Species Institute's website, the hammerhead flatworm originates in Southeast Asia and have an affinity for warm climates. Its name comes from the hammerhead shark, given its rounded "half-moon shaped head." Their body is also considered "snake-like," as the average hammerhead flatworm can grow between eight and 15 inches long.

According to a report from KTVT, the institute credits a viral Facebook post with raising awareness of the invasive species' presence in Texas. Debbie Meyers-Shock wrote on June 22 about the discovery of a flatworm in Dallas in a post that has since been shared over 71,000 times on the platform.

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"This species preys on earthworms and has no known predators due to the neurotoxic slime and therefor destroys the quality of our Texas soils, like the Zebra Mussels have done to our Texas lake waters," Meyers-Shock warned.

Morgan-Olvera confirmed with Newsweek these flatworms can be dangerous to humans. She explained that as the hammerhead flatworms prey on earthworms, it causes the invasive species to secrete a neurotoxin that poses a great threat to anyone that touches them or eats them.

"This invasive flatworm harms our ecosystem by preying on earthworms that are necessary for the health of our forests, rangelands, gardens, etc.," she said. "It also secretes noxious chemicals for predatory defense and earthworm digestion. Those chemicals can cause skin irritation on humans and make domestic and range animals nauseous and sick for several days if they eat them.

"Furthermore, many invasive flatworms, slugs and snails transmit harmful nematode parasites. All of these reasons are why we stress the removal of this species from your property and are tracking its distribution," she added.

The Texas Invasive Species Institute website also encourages anyone who accidentally touches one of the hammerhead flatworms to wash their hands "in warm soapy water, and rinse in alcohol or a standard hand disinfectant."

"If you do touch the flatworm please wash your hands...especially before touching your mouth," Morgan-Olvera added.

Meyers-Shock also shared tips with her Facebook following on how to properly dispose of one of the worms should they find one on their property.

"If you find one, take a picture and send to [the Texas Invasive Species Institute], then destroy it BUT DON'T CHOP IT UP!!! EVERY PIECE WILL REPRODUCE !!" she claimed. "[The Texas Invasive Species Institute] says to insure disposal to place it in a sealed baggie with salt and freeze it for 48hrs then trash it."

Toxic invasive hammerhead flatworm in Texas
After a concerned citizen flagged on Facebook she had found an invasive and toxic species of worm in her yard, the Texas Invasive Species Institute has issued guidance should citizens come into contact with the worm. LEFT TO RIGHT: GENEVIEVE ROLLAND-MARTINEZ/AFP/Getty Images, LILLIAN SUWANRUMPHA/AFP/Getty Images

Morgan-Olvera confirmed with Newsweek it is key that the worms be disposed of properly, else it could continue to invade Texas.

"For proper removal it is important that you do not cut up the flatworm, it will regrow from the segments!" she said. "Flatworms normally reproduce by splitting, so if you just cut off the head of the flatworm, it will regrow another one and continue to survive.

"When you see a hammerhead flatworm use gloved hands, a paper towel or a stick to pick up the whole creature and place as many as you see in a Ziploc bag with some salt, seal the bag and throw them away," Morgan-Olvera added. "What is most important is to get the whole flatworm and seal the bag before disposal so it cannot crawl out."

Newsweek reached out to Meyers-Shock for additional comment on her viral post, but she did not immediately respond in time for publication.

This is the latest invasive species to threaten Texas. A highly invasive species of jumping worm first spotted in Wisconsin in 2013 was reportedly found in more than a dozen Midwestern states in April.