Worm ID?

[Kayla]

Hi all, I found 2 of these crawling on the glass of one of my tanks tonight (I’m sure there’s more but I didn’t see them). The head doesn’t look pointed to me, any ideas? It was hard to catch on camera since it’s so small so it might be a little blurry. The blue line is the head as it was moving down the glass.

Edited January 9, 2021 by Kayla

[Colu]

It could be a planeria worm

[David Ellsworth]

If you watch it does it stretch out to be really thin (like double their body length or more) and flat and scrunch much smaller as it crawls along the glass? Do you ever see them free swimming like little flat ribbons in the water? I have some just like I described from plant hitchhikers in a dirted tank. Mine is a type of leech. The type I have look to be harmless to fish, but they predate on the microfauna in the tank. 

 

I'm not an expert, but my internet research tells me that if they are wormlike and stretch out and contract it is almost always a leech of some type. Not much else that has that characteristic. If they are always on the glass, never free swim, and inch along the glass without contracting, then it could be planarian like the above poster mentioned. If it is a leech some fish will eat them. 

Edited January 9, 2021 by David Ellsworth

[Kayla]

@David Ellsworth It like wiggled down the glass, wish I could post the video lol. I attached pictures that I took from the video and you can see it’s moving side to side kinda. Not sure if it’s ever in the water column as it’s so tiny idk how I even saw it last night plus my substrate is white so it’s even harder lol. One of my Ranchus tried to eat it tho

[Daniel]

@Lizzie Block had a good post on how to attach video:

 

[Kayla]

@Daniel thank you so much!

[David Ellsworth]

I really lucked out in my video. I started recording and he swam away. Is your like this? If not I'd google Freshwater Aquarium Hitchhikers and several sites have a very exhaustive list of anything you are likely to see from a purchase for your tank.

https://youtu.be/RqNf9fvKKhw 

[Kayla]

@David Ellsworth no it’s much smaller then that. From researching maybe planaria or Rhabdocoela? I can’t tell if the head is pointed or not cause of how small it is

[Sapere_Ceta]

I think it is Rhabdocoela, as they have a wider and rounder head and a much rounded end. Although unsightly, they are harmless and clean up waste in the substrate. You could see if cleaning the substrate more often could deplete it’s food source, therefor killing it eventually. Some chemical means are used to eradicate them, but it might not be the best route to go. 
You could also use a siphon to suck it up possibly and then kill it. You could also take a plastic container and put it over them and wait [very] patiently until they go to the back of it. Then gently slide it along the glass and lift it out of the water when you’re able to. 

[Kayla]

@Sapere_Ceta thank you! I was leaning towards that too, since I couldn’t make out a pointed head. I don’t see a lot so that’s good lol. I’m definitely going to try gravel vacuuming more often.