[Josh H.]

a day or so ago i saw some fry in my 5.5 gal tank, i only have zebra danios and a couple cherry shrimp, so i figured it was from the danios. then suddenly i saw none, figured they got eaten. then i wondered if some got into the filter, so i dumped the water from the filter into a bucket. after everything settled down, i saw no fry, but did see a bunch of tiny black dots darting around at the bottom. its not that i'm worried they might be parasites or anything, just curious as to what they might be. thinking about getting a microscope (really its just an excuse to get one) to see what they are. anyone ever see something similar?

 

[steven p]

Seed shrimp against a white background?

 

[Josh H.]

looked into it, apparently red cherry shrimp dont go through a larval stage, so i ruled that out, as they dont look anything like a shrimp.

 

[steven p]

Cyclops? Daphnia? Moina? Likely no reason to fret and some people may be interested in them depending on what they are.

 

[papwalker]

Chuck 'em back in. They are likely harmless and might even be useful.
Tom over at seriouslyfish has a tank full of little gribleys and it's thriving.

http://www.seriouslyfish.com/forums/my-aquarium/toms-bucket-o-mud/

He rarely feeds anything nor runs a filter and all the micro-flora, fish, inverts and plants are doing great.

Scroll down his thread the brilliant video of the tank.