A blue colored respiratory pigment called hemocynanin is found in:

Explanation

A blue-colored respiratory pigment called hemocyanin is found in mollusks. Hemocyanin is a copper-based oxygen-carrying protein that plays a vital role in oxygen transport within the circulatory system of many mollusks. In most vertebrates, oxygen is transported by the iron-containing protein hemoglobin found in red blood cells. However, in some invertebrates, including certain mollusks, the oxygen transport is achieved by hemocyanin. Hemocyanin is found dissolved directly in the blood plasma, rather than within specialized cells like hemoglobin. When mollusks are exposed to oxygen, hemocyanin binds with the oxygen molecules, forming a blue-colored complex. This oxygenated form of hemocyanin is responsible for transporting oxygen from the gills (or other respiratory structures) to various tissues throughout the body.