Coelom vs. Haemocoel

Coelomnoun

(zoology) A fluid-filled cavity within the body of an animal. The digestive system is suspended within the cavity, which is lined by a tissue called the peritoneum.

Coelomnoun

a cavity in the mesoderm of an embryo that gives rise in humans to the pleural cavity and pericardial cavity and peritoneal cavity

Coelom

The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium.

Haemocoelnoun

(biology) The cavity, between the organs of arthropods and molluscs, through which the blood etc. circulates.