Centipede? Worm? Larvae? Any ideas?

[Deadeye]

Just found this crawling around one of my tanks - not sure how it got in but I’m curious what on earth it is.

It gives me centipede vibes but doesn’t move like one. It acts like a marine bristleworm or a similar annelid.
If I see it again I can try to get a good shot of it’s head.

 

[tlindsey]

centipede

That's exactly what it looks like to me also.
Never seen anything aquatic like that.

 

[duanes]

I wonder if its Scolopendra cataracta, a recently discovered amphibious centipede?
Venomous and a carnivore, from South East Asia.
Did you get any S E Asian plants, that an egg could have hitched in on?

 

[Deadeye]

There’s a few Java ferns, but those would have been in there for a long time. Everything else is either an American or African plant (Val, hornwort, Anubias, duckweed, aponogeton). All of those have been in there for just as long though.

 

[Fallen_Leaves16]

It looks like a garden/greenhouse millipede that either hitchhiked or got into the tank somehow. Sometimes they fall into my tanks, though I've never seen one wander about underwater, just flail and drown instead.

 

[fishhead0103666]

I can confirm that is a millipede, one of the flat millipedes, which one I don’t know unfortunately.

 

[Deadeye]

It does look a lot like the garden millipede.