What is the difference between the human circulatory system and fish circulatory system?

Hint: Circulatory system is the network of organs that allow the circulation of blood throughout the body. It is essential for the transport of blood to all parts of the body as it carries nutrients, oxygen, carbon dioxide, hormones and waste in the body. Major components of the circulatory system include- the heart, blood and blood vessels.

Complete answer:
Following are the differences between the human circulatory system and fish circulatory system-


Additional Information:
FISH CIRCULATORY SYSTEM
The circulatory system in fishes consists of heat, gills, blood and blood vessels. Heart of a fish is two chambered with one atrium and one ventricle. There is unidirectional flow of blood. The atrium receives deoxygenated blood from the body and passes it to the ventricle, which pumps the blood to the gills where gaseous exchange occurs and the blood becomes oxygenated; this is called gill circulation. The oxygenated blood travels through the body and returns to the atrium; this is called systemic circulation. This unidirectional flow of blood limits the amount of oxygen reaching some tissues and organs, thus, reducing the overall metabolic capacity of fish.

Note:
There are following two types of blood circulatory system-
1. Open circulatory system- Blood flows from lacunae, large open spaces and through sinuses among the tissues. Tissues are in direct contact with blood so the exchange of gasses and nutrients takes place directly. It is found in amphibians.
2. Closed circulatory system- Blood does not come in direct contact with the tissues. The blood flows through a closed system of arteries, veins and capillaries. Nutrients and gasses pass through capillary walls to tissue fluid. It is more efficient than an open circulatory system. It occurs in molluscs, echinoderms and all vertebrates.