The freshwater perch demonstrates the characteristic anatomy of the class Osteichthyes—the bony fish. This is the largest class of vertebrates both in number of species and number of individuals. Like the cartilaginous fish, the bony fish possess a two-chambered heart but differ in the development of a complete bony skeleton and a buoyancy-regulating swim-bladder. The gray perch is a less expensive alternative to the yellow perch. Dissection manuals for the yellow perch can be used. Measured from the tip of the head to the tip of the tail. Flinn-Preferred™ preserved specimens are safe, non-toxic alternatives to formaldehyde preparations. These specimens retain a more lifelike and natural appearance and have not been exposed to formaldehyde at any point. Look for the Flinn-Preferred™ symbol!