Flatworm or Snail Larva?

[dapellegrini]

Well I just torn down my 3g again -- seems to become a snail breeding tank, instead of a RCS breeding tank. Last time, I thought I removed all the ramshorn and pond snails...

Two things I have noticed in this tank, and I am wondering if either of them are snail larva. Here are the inhabitants (that I know about) in the tank:

- Red Cherry Shrimp
- Bee Shrimp
- Olive Nerite Snails
- 1 Large MTS
- 1 Small MTS
- Misc Ramshorn (Red ones and brown speckled ones)
- Pond Snails

(I have just made another attempt at eradicating the Ramshorn and Pond Snails)

I have pics of one of the two creatures that I would like to identify. The non-pictured creature is is a free-swimming, very white, round, worm thing. Perhaps 5mm in length. Wiggles violently in open water until it lands on something... I was wondering if this might be the Nerite hatchlings (eggs everywhere) that never survive... If not, what could it be?

The 2nd one is here in a series of pics so you can see it moving. I suspect this to be a flatworm, but am not sure:

 

[Zezmo]

They look very much like leeches. It looks a bit large to be common planaria relative to snail size. Those look like the same creature in all pictures.

 

[dapellegrini]

Ya, the series of pics are all of one of the #2 creatures moving. You can see the pool filter sand there too for reference to size...

 

[CHBGator]

That looks like a Planaria, they range from about 3 to 12 mm.

 

[dapellegrini]

Hitchhikers? Last time I tore down this tank, I rinsed and removed all signs of snails, etc but somehow these guys survived... Thus my pondering as to whether these or the small white things might be snail larvae.

This time around most everything, including the driftwood, filter, rocks, etc was placed in near-boiling water for about 25 minutes

They do look like pics of planaria and leeches, but I am guessing planaria at this point.

Does anyone know where I can find pics of Nerites in their Larvae stage? Unknown #1 is a small (~5mm), round, white worm that wriggles violently in the water until it lands on something. Seems to be its mode of transportation. Unfortunately my camera is incapable of photographing these guys... I am suspecting them to be nerite babies, as they never seem to be around for long, but I could be completely wrong...

 

[JDogg]

hard to tell for sure without a closer picture, but i am voting leech... planaria have more a defined "head" and two light sensing spots that make them look cross-eyed (at least the ones i use in my Biology labs do)

 

[Zezmo]

planaria
http://www.eeob.iastate.edu/faculty/DrewesC/htdocs/planaria-Lv3.JPG

other stuff you might not wish to find in your aquarium.
http://www.eeob.iastate.edu/faculty/DrewesC/htdocs/invert-thumbs.htm

Here is an AA thread about "hitch hikers"
http://www.aquariumadvice.com/viewtopic.php?t=87363&highlight=nightmare+hitchhikers


BTW.... Do snails have larva? I was under the impression they hatch from the egg as miniature versions of adults.

 

[dapellegrini]

That planaria pic looks nothing like the one I was looking at:

http://en.wikipedia.org/wiki/Image:Smed.jpg

I guess many different types...

I think some snails do have a larvae stage. Here the refer to a nerites larvae stage for instance:

"Apparently the larval period and requirement for planktonic food limits the successful recruitment of nerite larvae"
http://www.advancedaquarist.com/issues/sept2003/invert.htm