Tiny little things in tank

[JamesBenjamin]

We have a 10g tank that was a birthing/grow out tank that we recently moved all the babies out of, then tossed in a small sponge filter, and a large snail to keep the tank 'cycled' till we need it again. (there's one swordail in there too)

Well, today we noticed that there are a whole bunch (hundreds?) of little tiny things that look like tadpoles, they're white, and are about as long as the head of a pin is wide.

The sponge filter came out of a tank that had 5-6 ghost shrimp in it, could these be baby ghost shrimp? I know they're not baby snails, cause there's a few of those in there too, and they look totally different. They move really quickly too.

Any clue what these could be? I would post a pic, but you wouldn't be able to see them in it!

Thanks!

[JamesBenjamin]

=(

anyone?

[wetmanNY]

Copepods? They taper like tadpoles and they're real small.

[kveeti]

This is a bookmarked page I have, it is really neat:
http://www.microscopy-uk.org.uk/pond/index.html
Go down to 'anthropods' page and then 'tadpole shrimp' there are much magnified pictures, maybe that could be what you have?
(or go directly to it here)
http://www.microscopy-uk.org.uk/mag/artjul00/dwtriops.html

[wetmanNY]

That's a brilliant website, isn't it kveeti? Inspired me to get a microscope.... as a gift! Not a fancy one though... like a nice toy... Just right for peering and lurking...

Triops are fairly rare, I think...