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Blue flatworm

Caenoplana coerulea


Usually 30mm long but incredibly stretchy.
Very dark blue (black-blue) with a single dorsal line of yellow to white.
The underside is paler but all colours can vary with the angle of light.


Found under a large wet log in an outer urban back yard along with another geoplanid species and many other small creatures.


Several of these found today which is no surprise considering the good rains we have had lately.
Although native to this part of the world they have been introduced to many other places now. Sorry overseas people but we have a lot of your lost critters too.
They prey on woodlice, small snails and slugs, other small arthropods everting their stomaches to ingest externally.

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Mark Ridgway
Mark Ridgway a year ago

I'd love to find a video of it in action.

Neil Ross
Neil Ross a year ago

Cool spotting and notes, Mark! It does what with it's stomach? I must check this out!

Tukup a year ago

Ooh. That's even prettier than the other one. I would imagine the slime is the same color though :-) Great shots. Thanks Mark. I appreciate your good precise notes too.

Mark Ridgway
Spotted by
Mark Ridgway

Victoria, Australia

Spotted on May 23, 2020
Submitted on May 23, 2020

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