[asquirrel]

Got these things in my tank. Fast movers. They move super fast in spurts. Tiny. About the ¼ of the size of a BB.

Slugs. Two types. Black slugs and white slugs.

Here’s videos.

In a cup

In my 5 gallon bucket. 1st 15 seconds you can see it. Black slugs.

White slug on side of tan glass.

Used Prazipro. Dosed then waited 7 days and dosed again. Thought they were all dead. Didn’t see any the following week but now they are back.

I have one mystery snail, one black racer snail and one striped nerite snail.

One emerald corycat.

Three amano shrimp and 12 red cherry shrimp.

Tank:

20 gallon long.
Water temp is about 70f.
PH – 7.2 – 7.5. Ammonia – 0. Nitrites – 0. Nitrates – 0-5. GH – 6. KH – 2-3. Phosphates. 0.5 – 1.0 ppm. Water change of about 8 gallons every 7 days. I add seachem safe, equilibrium, flourish and excel. Also scrape some mineral stone in there.

Feed them 1x a night. One shrimp pellet (wardley). Two hikari crab cuisine pellets. One quarter of omega one veggie rounds. A few wardley fish flakes. ¼ of Tums generic calcium tablet. Have couple of eggshells. Oak leaves. Cinnamon sticks. Cassia and Ceylon.

Plants – amazon sword (2). Wisteria and Java moss.

Was losing 2-3 shrimps a week from a group of about 50-70 (started with 2). Temp was in high 70’s – low 80’s. Had algae problem even with scrubber (either algae or cyanobacteria. It was non-hair type). Lowered temp to 70f. Added leaves, egg shells cinnamon sticks. Generic tums. No further shrimp deaths.

Have had this 20 gallon running for three years. Have had this funky worm / fast mover thing for at least 3 months now. Probably longer.

Question – what the heck are these things? Detritus worms? The fast movers can’t be detritus worms – they’re too small and fast. They aren’t hydra. No spikey things. Flatworms? Emerald corycat is okay.

I find these things on the side of tank glass in the morning when I turn the light on. The worms / slugs don’t seem to like light. I won’t see them that much during the day. I see them but not many. When I turn the light on they usually go down into the substrate. The fast movers don’t care whether there is light on or not. They’re easily as fast as the shrimp when the shrimp do their leap thing to get away from danger.

What else can I do to get rid of these things? More prazipro? I heard if I use febendazole it will kill my shrimp and snails. Thanks for whatever info you can provide.

 

[Zoidburg]

I can't tell what any of them are, but the white ones could be either freshwater limpets (move very slowly, they are snail relatives) *or* rhabdocoela flatworms - both of which are harmless.

Black or dark ones might be some sort of tiny Procrustean or? Like a scud or gammarus?

 

[asquirrel]

I can understand why you'd think the white one might be a limpet My phone video recorder really sucks. The image is fuzzy so the thing looks round. The white thing looks more cylindrical / torpedo shaped in real life. I think you might be right on the second guess rhabdocoela flatworms, at least for the white guys. I wonder if they come in different colors? The black ones I took video of a long time ago. The white ones were just today.

Now I wonder what those fast mover things are. They move really fast. As easily as a fast as a shrimp when they flap their tail thingy to escape.

Any ideas on how to kill them? Maybe just keep redosing the prazipro every 7 days until there are no more eggs?

 

[Zoidburg]

The flatworms are at least harmless.

The others, if scuds, well, depends on who you talk to.

Fish that hunt may eat them (guppies, bettas or?). Other than that, well, what may kill them may also kill the other inhabitants. Could always try setting up traps or using a turkey baster to suck them out?

 

[asquirrel]

I was thinking of maybe getting a betta or a guppy to seek and destroy these things. My concern is that I've read bettas and guppies would see my red cherry shrimp and consider them an appetizer until their evening dinner arrives. Trap maybe. I don't think that planaria tube trap would work on the scuds. They seem to be having a blast zooming around the tank and enjoying the utter indestructibility. It would be nearly impossible to catch those fast movers (scuds?) with a turkey baster. They're more fast and agile than an Olympic gymnast.

Soooo . . . bad idea to put a guppy or betta in there? I remember when I had a betta way back when he would terrorize all my other fish, but made a pet project out of my buddy Emerald Corycat. Funny thing was that the betta was about 1/3d the size of Emerald. A guppy isn't a total aggressive loon like a betta but would probably hunt and kill my red cherry shrimp. Not sure what I should do.

 

[Zoidburg]

If you don't mind removing the shrimp temporarily, go for the fish! If you don't want to, then get something like an endler, although I don't know if they'll go after the scuds. They are good at getting the other small bugs though, like copepods (cyclops).

 

[asquirrel]

Hi Zoidberg,

Just wanted to give you a quick update. I used the Prazipro a couple of days ago and those worms and fast movers were nowhere to be found when I turned the lights on this morning. Going to dose again next week and see if these things stay dead. Thanks for your help!