What is this Aquarium worm? (Solved! Drain Fly Larvae)

[Naidisbo]

I'm no artist but I had to draw them with MSpaint because I couldn't get a decent picture.
Small, fast, wriggly little things.

Alright so I've already had to fight with Callamanus worms that were in some platies and nuke the tank with Fish Fenbendazole and do three 100% water changes, which ended up killing the snails I had in there which caused an ammonia spike because I couldn't find all the corpses, which killed the last two Platies I had that survived the Callamanus infection! ... Are these just what Detritus worms ACTUALLY look like up close? Or is this ANOTHER parasite that I should be worried about?? They seem to be slightly thicker and shorter than the pictures of detritus worms I've seen. They also have a very dark black head and rear that I haven't seen in pictures of Detritus worms. They almost look like thin, elongated gnat larvae?? I haven't been able to find anything that looks like them online and I already checked the "Common Hitch-hikers" thread.

I grabbed one out with tweezers, and an hour later it's still alive! There's a ton of them, but they retreated into the rocks when I grabbed the one.


Here's some tank information if needed.
Zebra Danios x5 (Full grown | Replaced the 5 Platies, been in tank for about three weeks)
Young Tyretrack Eels x2 (A bit more than 3 inches each | Original tank members)
Young Albino BN Pleco x1 (Probably only an inch 1/2, maybe two inches. | Original tank member)

I know I'm overstocked as I was told by Petsmart it's Inch-per-LITER! I didn't know it was inch-per-GALLON. I do frequent water changes however, 30% - 40% water changes every couple days. I've had the tank for a little over a month, and I'm already planning on getting a 35 gallon for everyone in my 10 gallon, and I'm probably going to breed live food in the 10 gallon.
I haven't tested my water in awhile but I'm going to be getting it tested in a couple days.
The last test came out with fine PH and Ammonia levels, but Nitrate was a bit high.

 

[Naidisbo]

I've been grabbing them out whenever I see them. They're actually pretty interesting. They last a long time out of water as long as they aren't completely dry, I held one in my hand and they don't do damage. I'm thinking they're just a decomposer, but I'd still like to know if anyone can figure out what these are?? I found microscope views of Detritus worms and they DO NOT look like whatever these are, they are most DEFINITELY not Detritus OR Planaria.... Which worries me a lot! These things survived the Fenbendazole treatment, as I had seen them before I used the stuff thinking they were Callamanus larvae or something (They are not). As far as I know, an overdose of Fenbendazole would kill a whole tank - But I dropped some pure Fenbendazole into the cup I had the worms/larvae in, AND IT DIDN'T KILL THEM! The amount I used would have even killed a fish. What ARE these things??

 

[LyraGuppi]

Could they be mosquito larvae?

Also, even the inch-per-gallon rule is outdated, unfortunately.

 

[Naidisbo]

Could they be mosquito larvae?

No, they're far too worm-like and don't move as erratically... But it DOES look more like some type of larvae than a worm. Just a few minutes ago I spotted a tiny fly of some sort inside the tank, so it's possible it's some type of fly I've never heard of? Most insect larvae I see in water keeps to either the top or middle sections, but these never really leave the gravel so I'm not sure.

Also, even the inch-per-gallon rule is outdated, unfortunately.

I've started to notice that. The Danios I have in there seem really cramped and stressed, and one's starting to get picked on quite a bit. The eels seem alright. They're wiggly and happy, and they don't do much swimming around so much as playing in the plants... But I'll definitely try to get that 35 Gallon as soon as I can, replace the gravel with sand as well.

 

[LyraGuppi]

Odd! I'm sorry, I have no clue. Hopefully someone else can figure this out.

 

[Naidisbo]

Odd! I'm sorry, I have no clue. Hopefully someone else can figure this out.

Very odd... Thanks for trying to help though!
The community here seems very polite~

 

[cowgirluntamed]

Google drain fly larvae. I had these in an hob filter at one point. They seem similar to what you drew. And when you mentioned a fly going there it could very well be it. I never did see them in my gravel I had at the time though, they hung out in my filter sponge. But to get rid of them basically means lots and lots of really good cleaning. Inhad to break my hob apart and clean it really good. Changed the sponge out and cleaned that off regularly and the flies weren't attracted to it any more.

 

[Naidisbo]

Google drain fly larvae. I had these in an hob filter at one point. They seem similar to what you drew. And when you mentioned a fly going there it could very well be it.

Ah, that's DEFINITELY them!! I've only seen them in the second larvae stage... Hah, I don't think the Eels and Danios let them get big enough to really be noticeable outside the gravel! I've only ever seen a couple of the adult flies before.

Thanks so much~!
I'll up the gravel cleaning to see if I can lower the amount in there, but I don't think the fish mind them very much after all. Because I've never seen them get any bigger, I think they're just simply getting eaten once they leave the gravel. That could be why the Danios look like they're getting fatter.

It's a load off my mind though, Thank You so much!

 

[cowgirluntamed]

No problem! Glad I could help!