What are these worm-like creatures?!

[Spongiform]

I built a small terrarium earlier this year. It's a 20 Gallon-Long with a divider splitting it up into 2/3 water 1/3 land. I keep the water about 6 inches deep.

Everything that's ever been put into it came from local creeks, ponds and rivers.

I live in Northern Virginia (bout 2 miles from the Potomac). I've put several small fish caught from local creeks. It's had a crayfish or two. A garter snake. Snails and various tadpoles. I re-released alot of the critters as they got too big.

Right now all I have in it is a water turtle, some snails and a bunch of worm-like creatures.

They live in small muddy spots in the tank. They poke up from the mud and wriggle endlessly back and forth. They're anywhere from to small to really see to a bout 1.5CM. I havn't seen any larger then that.

They're always doing 1 of 3 things that I can see.

1: Buried, nothing that I can see
2: Wriggly frantically back and forth for hours on end.
3: Sticking out but completely still.

I've tried to capture one before, but they just retreat down into the gravel and move amazingly fast for their size.


So any idea what in the world these are? I don't think they're harmful or dangerous.. they're actually pretty neat to watch. I just want to know what they are.

~
Spongiform

 

[angel51431]

are they white-clearish? Sounds like planaria. They are harmless flatworms that reside in the substrate. Every tank has them, they usually live in the gravel and aren't seen unless the gravel is stirred up). Though when you see them out in the open chances are that you have a rather big population. Planaria populations grow large when there is an abundance on food and decomposing stuff in the substrate. Though the planaria themselves are harmless, the fact that there are a lot of them means that you need to vacuum that gravel and clean up a bit, because your fish and other creatures might suffer from dirty water more than anything.

Speaking of which, how big are those fish? If the fish are only getting 2/3 of the length of the tank and its only filled about 6 inches, it doesn't sound like there is much room for them. Do you have a filter for the water? With all those creatures in there, its essential that you keep your water very clean, because its likely that it'd get messed up very quickly. That might be why you've got all those planaria.

 

[MissFishy]

Yeah, I second what angel said about keeping the tank water clean. It also sounds like whatever creatures you're catching are not getting a proper home. Garter snakes are living in 1/3 of a 20 gallon, so essentially they're living on the surface area of a 6 gallon tank? I'm no snake expert, but it sounds like you need to rethink stocking this thing...it's not fair to take animals from the wild and keep them in such small dirty quarters.

 

[angel51431]

Hmm, yeah - I know you said that you rerealease the creatures when they outgrow the residence, but in general just for keeping all those animals - turtles, tadpoles, crayfish, fish, etc happy, you'd need much bigger quarters. I mean alright, you take them from the wild - a lot of pet store fish are wild caught too for example (not all species are willing to breed captively). But since they're coming from seemingly boundless environments, it'd be much more... moral, if anything, to give them some room to move about. I'd say you definitely need a 30 gal + tank at the very least. And with wild caught creatures, you really need to try and keep the water crystal clean.

 

[Dan Steveo]

sorry but arent planaria really really tiny like 7mm max????

 

[Spongiform]

Well, couple things here. I never had all those critters at the same time. Just over a period of a year. Like the tadpoles, once they matured into frogs I released into a local pond. The snake was a tiny thing when I caught it, but once he was about a foot or so I let him go too.

Right now all I have in there is a water turtle and some insects (snails, etc.) and these worm critters.

Also to Missfishy - Garter snake's are at home in or near water as much as dry land. That snake spent atleast half his time soaking in the water among some plants.

The reason I mentioned it all was to provide background as to where the worms possibly came from to help identify them.

So I did a little research on Planaria. I have seen a couple TINY white worms crawling around on the tank walls so thats what those must be.

The larger ones are around an inch long (that can be seen sticking out from the bottom).

I used a flashlight to get a better look at them. They're pretty much clear/see-through. They're segmented and you can see a little line at each segment but otherwise they're completely clear.

I also think they might have a shell they retract into - I can't seem to catch them.

They're roughly as thick as a human hair (mine anyway). I drew a little picture to help illustrate.

 

[Spongiform]

Soooo.. any clue what these are?

 

[big54bob]

parisites or worms from the dirt

 

[Purple]

Definately not Planeria - they tend to stick underground unless stirred up (at which point they assume the logical position in the food chain in a tank full of worm eating fish).

Sounds like you've got yourself a varied eco-system going on in there.

 

[Spongiform]

Today I spotted the largest one i've seen yet. Somewhere around 1.5 - 2 inches long (that was visible).

I tapped the side of the tank and it stopped moving completely... I tapped again a little harder and it retracted down into the dirt in the blink of an eye.

It's definately not a slow moving creature!

There's quite a few of them now but most are pretty small (smaller the planaria I see). Just a couple of them are about 1 inch and that one giant one.

 

[Spongiform]

aquatic worms

Ok, last post. Finally figured out what these things are.

They're called "Aquatic Worms" Simple eh?

aquatic worm

The pictures shown there really don't look like anything recognizable. But the videos at the bottom(where are HUGE in size for some reason 150-322 megs) but are exactly what I have in my tank and the description fits them.

So in a nutshell these are aquatic earthworms. They bury their heads in the dirt and shake their rears in the water to poop. Supposed to be beneficial for the ecosystem and a good food source for small fish or other critters.

Case Closed!

Now all you fish tank pros know what to tell the next guy who has these!

~
Spongiform