PDN Photo of the Day website says:
Here we present ten of the finalists from Nikon’s 35th Annual Small World Photomicrography Competition, which recognizes photographs shot through a microscope. Contest winners will be announced on October 8. Until October 2, the public can select their favorites in the “Popular Vote” section of the Nikon Small World web site.
Above image: © Shamuel Silberman, Ramat-Gan, Israel
Embryo of guppy fish (40X)
Reflected light by fiber-optics