Worm ID?

[mike]

One of my tanks has an outbreak of these brownish worms:

They are very soft, do not appear to be segmented, crawl with the pointed end forwards, come in a range of sizes up to about 1.25 inches and emerge to crawl up the glass after dark or if I water the substrate heavily. I realize this is very difficult from just a photo, but can anyone ID these, and are they likely to be harmful?
Thanks.

 

[john]

I've no idea what they are but I do think they're very interesting little beasties. I wonder if one could culture them for live food? That's assuming of course that they're harmless.

 

[cataldo]

It reminds me of Ascaris lumbricoides. I know this doesnt help much and Im not right.

Is it a type of roundworm? (Nematoda)?

With over 4,000 worms out there, it's hard to know.

 

[john]

4,000 worms? Maybe 4,000 nematodes described (not sure) but I'm sure there are a lot more.

 

[mike]

Aha, the following information from Lars Österdahl via frognet:
They are nemerteans. Some call them snoot worms. Your measurement is a little high for the most common one;
and they use to be white-ish, not brown), Then they are not dangerous to the frogs, but they eat fruitflies, springtails (and also earthworms), so they will compete for the food.
What they do when they find frogs eggs is uncertain...
There is little chance that you will ever get rid of them.
Nemerteans are mainly marine animals. Some get pretty big, but these semi-terrestrial species don't get bigger than this.