Bradley S. Klapper of the AP, in HappyNews.com:
Mature females of the Paedocypris progenetica, a member of the carp family, only grow to 7.9 millimeters (0.31 inches) and the males have enlarged pelvic fins and exceptionally large muscles that may be used to grasp the females during copulation, researchers wrote in the Proceedings of the Royal Society, published Wednesday by the Royal Society in London.
“This is one of the strangest fish that I’ve seen in my whole career,’ said Ralf Britz, zoologist at the Natural History Museum in London, who helped analyze the fish’s skeleton. “It’s tiny, it lives in acid and it has these bizarre grasping fins. I hope we’ll have time to find out more about them before their habitat disappears completely.”
The previous record for small size, according to the Natural History Museum in London, was held by an 8-millimeter species of Indo-Pacific goby.
More here.