The image is showing a Shorthead Redhorse, Moxostoma macrolepidotum. The species is commonly found in large creeks and rivers across most of Illinois.  It is a member of the "sucker" family, Catostomidae, whose name originates from the ability to use their mouths to suck up small food items usually found on creek and river bottoms.  It can reach a maximum size up to 2 1/2 feet in length. The image sequence from top to bottom shows 3D volume rendering at different opacities/modules to show external surface (top), internal skeleton (middle) and psuedocolored Isosurface objects with range of ellipticity (prolate, color coded) from Xray CT data. The sample was scanned using the NSI X5000 High Resolution MicroCT and rendered in 3D using Imaris 3D visualization program at the Carl R. Woese Institute for Genomic Biology Core Facility.