Anatomy of finfish and shellfish

Unit 5 - Circulatory System

5.2.4. Arterial system in Bony fishes
Heart is similar to that of shark. But there is no “conus arteriosis” . However, the base of the ventral aorta is enlarged to form a non-contractile “bulbus arteriosis”.
Arterial system
The ventral aorta is comparatively shorter. It gives off 4 pairs of afferent brachial arteries through which venous blood is supplied to the gills ( 4 pairs) for purification. The blood from the gills is collected by 4 pairs of “efferent branchial arteries” In the bony fishes each gill arch has a single efferent artery unlike the condition in shark. The four efferent branchial arteries unite to form the lateral aorta on each side. The two lateral aorta are joined together both anteriorly and posteriorly forming a ring shaped vessel known as the “circular cephalicus”. In the anterior end, the external and internal carotids arise on each side form the circular cephalicus posteriorly the two laterial aorta fuse together to produce the dorsal aorta which supplies all the organs of the abdomen and ends in the tail.