The circulatory system of the crayfish is an open system where the blood is contained in vessels for only part of the system. The heart is located in a pericardial sinus located in the upper part of the thorax (a sinus is a sac or cavity). The heart pumps the blood into the arteries.

How many hearts does a crayfish have?

How many hearts does a crayfish have? You have four; two right chambers and two left chambers. Your two right chambers are called the right atrium and the right ventricle. The right chambers are blue, standing for deoxygenated blood.

Do crayfish have chambered hearts?

Describe it/them. You have four; two right chambers and two left chambers. Your two right chambers are called the right atrium and the right ventricle. The right chambers are blue, standing for deoxygenated blood.

Crayfish have two body segments, the cephalothorax, which is the fused head and thorax, and the abdomen. Past the head region, internally the cephalothorax contains major organs like the heart, liver, and gills. Externally we find the walking legs and chelipeds.