Question

The coelom in arthropods is reduced and known as 'haemocoel' because

• A. Coelomic fluid flows in the blood vessel.
• B. Blood flows in the blood vessels present in the coelom.
• C. Coelom is filled with haemoglobin.
• D. Blood flows in the coelom.

Answer 1

The correct option is D Blood flows in the coelom.

The body cavity or the coelom of arthropods and molluscs is filled with blood. The haemocoel is an enlarged blastocoel, which greatly reduces the coelom (this is restricted to the cavities of the gonads and excretory organs). The haemocoel can act as a hydrostatic skeleton. It is the characteristic feature of arthropods.