| Open circulatory system | Closed circulatory system |
|---|
| Hemolymph directly washes the organs and tissues. | The blood flows inside the closed vessels. |
| The blood & the interstitial liquid can’t be identified. | Blood & interstitial fluid are different. |
| Present in mollusks & arthropods. | Present in annelids & vertebrates. |
| Blood is pumped into the body cavity. | Blood is pumped through the vessels by the heart. |
| Dorsal blood vessels present. | Dorsal & ventral blood vessels are present. |
| Blood is in direct contact with the tissues. | Blood is not in direct contact with the tissues. |
| Nutrients are transferred directly among blood and tissues. | The nutrients are exchanged via tissue fluid. |
| No transportation of gases takes place. | Transportation of gases takes place. |
| The fluid that is circulating in the system is described as “hemolymph”. | The Fluid which is circulating in this system is called blood. |
| No respiratory pigments are present. | Presence of Respiratory pigments. |
| The volume of blood cannot be managed. | Volume of blood can be controlled by compression and relaxation of blood vessels. |
| The flow of Blood is slow. | The Blood flow is fast. |
| The open sections are termed as sinuses and lacunae. | The closed spaces involve arteries and veins. |
| Organisms with OCS: Snails, clams, cockroaches and spiders. | Organisms with CCS: Humans, squids, Cats, earthworms. |