Look out for invasive hammerhead flatworms following recent rains, report sightings

Invasive species can cause declines to native species populations, Texas State University Invasive Species Institute says

Hammerhead flatworm (Bart Everson, Flickr)

SAN ANTONIO – Be on the lookout for invasive hammerhead flatworms following the recent rainy weather.

The invasive species have been well-established in Texas for many years and are easy to spot due to their half-moon head shape. Invasive species can cause declines to native species through competition for habitat and food or disease and parasitic transmission, among other things.

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According to the Texas State University Invasive Species Institute, the hammerhead flatworm preys on earthworms, which are necessary for the health of forests, crops, gardens and compost piles.

Matt McClure with the TSUISI, previously told KSAT the only direct danger hammerhead flatworms pose to humans is if they’re ingested. They might also be eaten by an animal and then that animal might contaminate a surface if they become infected with nematode parasites.

These parasites are known to cause abdominal angiostrongyliasis in humans, which has symptoms like fever, abdominal pain and tumor-like lesions, according to Science Direct.

McClure stated that this can occur with other invertebrates as well and encouraged people to always wash their hands after encountering any organisms in general.

“Hammerhead flatworms also release a toxin presumably used to help them catch prey and avoid predators, which can cause irritation when handled,” McClure said.

Currently, there are no other known methods of control or bait that can eliminate the invasive flatworm without harming the ecologically-friendly earthworm, according to the Texas A&M AgriLife Extension.

Anyone who finds one is asked to submit a photo and the location coordinates to Asley Morgan-Olvera at invasives@shsu.edu so the university can track the spread of the invasive species.


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