Friday, 18 February 2011

There's life in the old pond yet

After a couple of months covered in ice, the pond sprang back into life last week. As well as some old familiars, the boatmen for example, the lack of larger bugs meant I was aware of some of the smaller (about 1mm) creatures on the surface of the pond. I think the photos here are copepods -- small crustaceans -- at the limit of what my camera can do.
The mustachioed animal on the right is probably Diaptomus castor, whilst the smaller fellow below may be Canthocampus staphylinus. If you think you know better let me know! Both are described as common in pools over the winter, and they move in a series of little jumps, which means that just as I focus the camera to take a picture they disappear from the view-finder.
 There ought to be a nice dimensional analysis argument to determine how light you have to be (and what size shoes you wear) before you can jump from the water surface. Too heavy and your foot would go through the surface. Presumably the surface is either solid or like a trampoline to these little fellas. Isn't surface tension wonderful!

Other denizens are more familiar. I think the bug on the right is a very young dragonfly larva, it was really small, about 2-3mm. Given the squat body and the dragonflies that laid eggs last autumn my guess would be that it is Libellula depressa, the broad bodied chaser, but that is only a guess.

The bug below is a lesser water boatman, Corixa; a very small specimen again but looking fine.

Note added later: I take back my first thought about the possible dragonfly larva -- no idea what it is!!

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