2: CARDIOVASCULAR SYSTEMS IN PRIMITIVE FISHES: 5. DETAILS OF THE CIRCULATORY SYSTEMS IN POLYPTERIDS, GARS, AND BOWFINS.

Chapter 2 Section 5 of the book "Primitive Fishes" is presented. This chapter offers an overview of the various patterns of change evident among primitive fishes. It outlines the primitive fishes' anatomical patterns like the heart, branchial circulation; and, the physiological patterns. A high-proportion of primitive fishes are air-breathers, and this has resulted in numerous cardiovascular modifications that allow varying degrees of functional separation.