Unidentified tank critters

[TJ]

Can anybody tell what these are or might be? They're on the glass in one of my tanks that contains newts, a couple of big snails and some Yamato shrimp. They may look big in the pic but they're actually quite small, say just a bit larger than a grain of salt. They don't seem to be moving. I haven't encountered them before.

 

[mark]

Could they be eggs from your snails or shrimp?

 

[TJ]

Hi, Mark. Well, I mentioned the snails and shrimp being in the same tank precisely because I was wondering the same thing

Shrimp, I highly doubt, but snails...maybe. They're much much smaller than these annoying organisms that have long been infesting my P.waltl tank:

I forgot what these are. Somebody, Ralf I think it was, identified them for me once. They're supposed to be harmless. They crawl all over the place and multiply rapidly.

 

[john]

Mark - what you have there is a sort of fresh-water limpet. They're harmless (and quite hard to get rid of without drying out a tank for a few weeks). I had them for years in Bristol but no longer since I moved countries (the tanks were dry for too long). They actually should help to clean the glass.

Tim - those are planaria (free-living flatworms).

 

[jennifer]

Tim, thank you for letting me use these photos in the "Tank Critters" article on Caudata Culture.
http://www.caudata.org/cc/articles/Tank_critters.shtml

 

[TJ]

Sure thing Jen

Here's more:

I found this caterpillar-like critter crawling around in my P.caudopunctatus tank this evening. Identification anyone?

 

[john]

Heh, that is a caterpillar. There are several species of moth whose larvae feed on aquatic plants - it wouldn't surprise me if it turned out to be one of those.

 

[TJ]

An aquatic caterpillar? Thanks for the identification, John. It must have hitched a ride in on a plant. Don't know if it would pose any danger to the newts, but I removed just in case. Surprised it hasn't been eaten because it sure looks tasty!

 

[ralf]

Looks like a larva of some kind of caddisfly to me. The species are quite different in appearance. I am no expert though on these macroinvertebrates, especially not the Japanese ones.

Found pics on the following sites whilst googling:

http://life.bio.sunysb.edu/marinebio/fc.4.fauna.html

http://www.kidfish.bc.ca/caddis_cycle.htm

http://web.utk.edu/~tcampbel/InvertFieldTripRiver.html

Ralf

 

[john]

I would agree with you Ralf but for the leg configuration - it perfectly matches a Lepidoptera caterpillar.

 

[ralf]

Guess you are right John. Found a pic of an aquatic caterpillar larva of the genus Synclita on the following website:

http://www.nature.ca/rideau/b/b5b-e.html

Ralf

 

[sari]

Just out of curiosity, how big is that caterpillar?

 

[francesco]

I think the creatures in tim's 1st picture could be aquatic snails that have just hatched. When just hatched their shell isn't spiralised but after a while it undergoes "torsion" becoming spiralised.

 

[TJ]

Sara, it was about 1.6 cm long.

Francesco, limpet, snails...your guess is as good as mine...probably better!

John & Ralf, thanks for the investigative work!

 

[kaysie]

Francesco, just a bit of semantics: torsion is the act of the shell turning in a horizontal fashion, making the back of the shell into the front of the shell. coiling is what causes the shell to spiral.

 

[francesco]

Well the italian word for what I meant is "torsione" don't know if the equivalent in english is torsion or coiling.
Ciao

 

[s1ren]

I have those limpet/snail deals, too. I thought they were young snails, as well. I wonder, now, though - if they were young snails, wouldn't they get bigger, eventually? My large tank has had those for four years, and I've never seen one longer than about 2mm.

 

[TJ]

 

[a]

Ive still got the limpets with my paramesotritrons, and it seems to entertain the newts, they spend hours trying to eat them when theyre on the rocks, when theyre on the glass they cant get them off!

AJfr0ggy