I used to fish a 35 acre lake in New England that had zooplankton large enough that you could see them with the naked eye. In fact they would actually come up into your ice hole bouncing around and apparently were quite active even in winter. The brook trout we caught through the ice were full of them.

I took some to school in seventh grade and we observed them with a microscope. Not sure how much the teacher knew, but she identificed them as "water fleas" which I'm sure is generic term. Bill?

Addtionally our local biologists here in northern Indiana maintain that zooplankton is an important food source for the trout that are planted in local lakes. One article says that rainbow trout can get to 3 to 5 pounds on zooplankton alone. However I personally don't see as fast a growth rate and as good a holdover in strictly zooplankton lakes vs. lakes that have gizzard shad or perch as forage fish.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.