Sharks

"It's tail swayed slowly from side to side, pushing the hunters body through the murky water. All signs of motion were non-existant, except for the rhythmic movement of the water over the five gill slits on either side of it's head. Slowly gaining speed, the shady figures unmoving eyes fixed on it's target, a lost harbor seal pup. As the distance between the predator and it's prey grew closer, the jaws of the massive fish …

…skeletal system reduces the weight tremendously and less force is exerted. A less obvious difference is the extra set of fins on the shark. The pelvic fins are located just below the dorsal fin on either side of the shark. The fish does not have the extra set of fins. It is determined that the extra fins are used to stabilize the shark during migratory swimming and hunting. [Editor's note: Bibliography not included by submitter.]