Yes, prawns have blood. However, it's more accurately described as hemolymph.
Hemolymph Instead of Blood
Unlike humans and other vertebrates with closed circulatory systems containing blood, prawns (and other crustaceans and many invertebrates) have an open circulatory system. This means they don't have veins and arteries that confine blood to specific vessels. Instead, they have hemolymph, which circulates freely throughout their body cavity (hemocoel), bathing the organs directly.
Hemocyanin: The Oxygen Carrier
The oxygen-carrying molecule in prawn hemolymph is called hemocyanin. Unlike hemoglobin in human blood, which uses iron to bind oxygen and gives blood its red color, hemocyanin uses copper. When oxygenated, hemocyanin gives the hemolymph a bluish tint. That's why prawn blood is blue-ish!
Key Differences Summarized:
| Feature | Prawns (Hemolymph) | Humans (Blood) |
|---|---|---|
| Circulatory System | Open | Closed |
| Primary Fluid | Hemolymph | Blood |
| Oxygen Carrier | Hemocyanin (Copper) | Hemoglobin (Iron) |
| Color (Oxygenated) | Blue | Red |
| Vessels | Absent | Present |
In summary, while not "blood" in the traditional sense, prawns have a fluid called hemolymph that serves the same function of transporting oxygen and nutrients throughout their bodies. Its bluish color comes from the copper-containing molecule, hemocyanin.
