What are the little white moving cells on Saltwater tank glass

Question

I just looked at the side of my fish tank up close, and saw some very minescule, white specs and they were moving!! I have a 55g saltwater aquarium with a porcupine puffer, green spotted puffer, snowflake eel, scooter blenny, lawnmower blenny, and a yellow tailed damsel. There are also snails and crabs. Anyone think that it is possible that they could be snail larvae. Are snail larvae mobile? I don't know what else it might be? My Scooter blenny is a big male, and I only added the lawnmower blenny a couple of weeks ago. The male scooter has been following the lawnmower blenny non stop raising his dorsal fin in what looks like a mating ritual, However, I doubt that the 2 species can breed successfully. Any thoughts would help!

Answer 1

Could be snail larvae but a much more likely guess would be copepods. do you have any liverock or live sand in the tank (they hitchhike in). They are harmless detrivors that will assist in the maintenance of the tank, reproduce like crazy and provide a nice food source for the livestock. Copepods are a normal and natural sign of a stable, running marine tank.

More information here.http://en.wikipedia.org/wiki/Copepods