What have we here?

My mystery object turned up in a sample of aquatic invertebrates and it's really quite tiny. This was taken at x 2.5 magnification. to show the detailed structure. It's been hanging around in the water for a while, hence the discolouration.

I'm afraid it's been a gloomy autumnal day here, so it was either this or one of the hordes of grey squirrels, feral pigeons and collared doves that are hoovering up our bird food. I counted at least eight squirrels in the garden today - they're all busy burying food in our lawn, which is beginning to have more gaps than grass!