[peterl]

I have recently noticed small (~.1 or .2 mm) creatures in my 15 gallon planted shrimp tank. They are whitish and swim with really jerky movements. I occasionally notice them on the back glass or in the java moss.

If they are live daphnia, how did they get into the tank? There has been nothing new added (livestock or plants) in at least 6 months.

TIA

Peter

 

[Malawidolphin]

They are probably "cyclops". They can come in on wood, plants, sand, rocks.....pretty much anything. They are harmless and if there are any fish in the tank the cyclops will soon disappear. they seem to magically appear. Ihad them appear in a 55 gal and I scooped some out and took them to the science lab at the high school I worked at. We put them under a microscope and sure enough they were cyclops. Very cool lookin under close up. Mine disappeared after I added a giant blue Gourami to the tank.

 

[peterl]

I figure they are some sort of copepod. The only inhabitants of the tank are A LOT of red cherry and tiger shrimp, and a trio of breeding otocinculus (plus fry). I expect these copepods are a new permanent resident of the tank.