The circulatory system of bony fishes, rays, and sharks is ...

[luvbio]

The circulatory system of bony fishes, rays, and sharks is similar to
A)  that of birds, with a four-chambered heart.
B)  the portal systems of mammals, where two capillary beds occur sequentially, without passage of blood through a pumping chamber.
C)  that of reptiles, with one pumping chamber driving blood flow to a gas-exchange organ, and a different pumping chamber driving blood to the rest of the circulation.
D)  that of sponges, where gas exchange in all cells occurs directly with the external environment.
E)  that of humans, where there are four pumping chambers to drive blood flow.

[coco]

Choose B

GL