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Hammerhead worm

Bipalium adventitium


A voracious predator of earthworms, this species is distinguished by the single maroon line running down its yellow body. It crawled slowly and left a track of shiny, mucoid secretions on the plank.


I found it underneath a decomposing wood plank that housed a termite and carpenter ant colony.


Bipalium is an invasive species in the US. Although found on land, this hammerhead worm produces tetrodotoxin to paralyze its prey, the same compound in pufferfish and a few other fish.

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Tukup 5 months ago

I did and I just posted it. It's a different species, but the second reference shows the head and stripes that identify both mine and yours. Thanks for the help Mauna..

mauna Kunzah
mauna Kunzah 5 months ago

Thanks for sharing that, Tukup! Did you happen to get a picture of it?

Tukup 5 months ago

I had no idea what a "Hammerhead Worm" was til this spotting. Then shortly after seeing it, I found one at my daughter's place. I'd never have noticed it without this spotting. Thanks.

mauna Kunzah
Spotted by
mauna Kunzah

NYC, New York, USA

Lat: 40.60, Long: -74.12

Spotted on May 11, 2019
Submitted on May 19, 2019

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