Diamond Darter

From U.S. Geological Survey (USGS):

Diamonds -- not just a girl’s best friend. The Diamond Darter is a rare species of freshwater fish, with a single population living in the lower Elk River, West Virginia. The species used to be found throughout the Ohio River basin in, Ohio, Tennessee, West Virginia and Kentucky. It was named the Diamond Darter by USGS researcher Stuart Welsh, because it sparkles like a diamond, especially when viewed at night with lights.

Adults grow to between 3 and 4 inches. A new finding from recent research is that Diamond Darter larvae have large teeth, but the adults do not, so the teeth may be embedded or lost during development from juvenile to adult. Diamond Darters sometimes bury into the sand on the bottom of the stream bed, possibly as a method to escape or avoid predation. (Photo by Stuart Walsh, USGS)