 actinopterygii , or the ray-finned fishes, constitute a class or subclass of the bony fishes. the ray-finned fishes are so called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays"), as opposed to the fleshy, lobed fins that characterize the class sarcopterygii which also, however, possess lepidotrichia. these actinopterygian fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the link or connection between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). in terms of numbers, actinopterygians are the dominant class of vertebrates, comprising nearly 99% of the over 30,000 species of fish.(davis, brian 2010). they are ubiquitous throughout freshwater and marine environments from the deep sea to the highest mountain streams. extant species can range in size from paedocypris, at , to the massive ocean sunfish, at , and the long-bodied oarfish, at . ==characteristics==  ray-finned fishes occur in many variant forms. the main features of a typical ray-finned fish are shown in the diagram at the left.  {| class="wikitable collapsible collapsed" style="text-align: left;" |- ! width=300px | fin arrangements |- | width=800px | ray-finned fish are varied in size, shape and the arrangement and number of their ray-fins. see fish fin. file:bluefin-big.jpg|tuna are streamlined for straight line speed with a deeply forked tail file:xiphias gladius1.jpg|the swordfish is even faster and more streamlined than the tuna file:salmo salar glerl 1.jpg|salmon generate enough thrust with their powerful tail fin to jump obstacles during river migrations file:atlantic cod.jpg|cod have three [[dor
Animal_classes Ray-finned_fish