What Type of Worm is This? Harmful?

[brubakec]

Video: What Type of Worm is This?

Can you help me to identify this worm?

I'm a new aquarist and I've never seen this before.  It is in a 10 gallon planted tank with snails (ramshorn and bladder) and red cherry shrimp.  Previously there were rummy nose tetra and, on another occasion, 2 reticulated hillstream loaches (temporary quarantines).  The substrate is mixed sand and gravel.

In the video the worm appears to pulse or breathe with the skinny end, reaching up towards the surface, possibly searching for food.  The stumpy end anchors it down until it decides to move on.  Turning up the lights or moving something around causes it to retreat into the gravel.  I managed to capture it by scooping that section of gravel.

Would this be harmful to fish?  That is my primary concern.  If it ate snails it wouldn't be that bad.  I wouldn't like it eating shrimps, but if it just ate fish poop and uneaten food I could possibly live with it 

Thanks.

[brubakec]

See pic.  It moves around by stretching the skinny end and then contracting body to pull stubby end forward.

[Daniel]

Looks like a leech.

[lefty o]

2 minutes ago, Daniel said:

Looks like a leech.

agree.

[NanoNano]

This might be helpful- https://aquariumscience.org/index.php/10-13-4-aquarium-leeches/.  An Asian Leech (Barbronia weberi) would be high on my list of suspects.