Circulatory System in Finfish and Shellfish

---

Circulatory System in Finfish 
and Shellfish 

---

Fishes are cold-blooded aquatic vertebrates and can be 
found in both saline and fresh water. The circulatory 
system of fishes is responsible for transporting blood and 
nutrients throughout the body. It has a closed circulatory 
system, i.e. blood travels across the body through the 
network of blood vessels. 
 
Fish heart carry only deoxygenated blood that is why it is 
called as 
Venous heart
. 
Circulatory system in fishes 

---

There are 3 basic type of heart found in animals: a 
2 chambered 
heart, a 
3 chambered 
heart, and a 
4 chambered 
heart. 
Fish have 2 chambers, one 
atrium and one ventricle
. Amphibians and reptiles have 3 chambers: 2 
atria and a ventricle. Crocodiles are the one reptilian exception, as they 
have 4 chambers (2 atria, 2 ventricles). Birds and mammals have 4 
chambers (2 atria and 2 ventricles).

---

Two type of circulatory system found in animal 
Closed circulatory system
Open circulatory system 
Vertebrates, 
and 
a 
few 
invertebrates, have a closed 
circulatory 
system. 
Closed 
circulatory systems have the 
blood closed at all times within 
vessels of different size and 
wall thickness. In this type of