chlorocruorin

biochemistry

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June 24, 2026

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Chlorocruorin is a respiratory pigment found in the blood of certain polychaete worms. Unlike hemoglobin, which is red, chlorocruorin appears green in dilute solutions and red in concentrated ones. It has a lower affinity for oxygen compared to hemoglobin. While hemoglobin is more common in annelids, chlorocruorin is present in groups like Flabelligerida, Terebellomorpha, and Serpulimorpha. In some cases, like in the polychaete Serpula vermicularis, blood can contain both hemoglobin and chlorocruorin. These pigments are crucial for transporting oxygen in annelids, especially in environments where oxygen availability might be limited.12

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annelid
Respiratory system
…respiratory pigment, either hemoglobin or chlorocruorin. Hemoglobin, the most common pigment, is present in most free-moving and some sedentary polychaetes and in most oligochaetes and leeches. Chlorocruorin is found in several polychaete groups (Flabelligerida, Terebellomorpha, and Serpulimorpha). A few free-moving polychaetes, some oligochaetes, and rhynchobdellid leeches have colourless blood. The…
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…respiratory pigment, either hemoglobin or chlorocruorin. Hemoglobin, the most common pigment, is present in most free-moving and some sedentary polychaetes and in most oligochaetes and leeches. Chlorocruorin is found in several polychaete groups (Flabelligerida, Terebellomorpha, and Serpulimorpha). A few free-moving polychaetes, some oligochaetes, and rhynchobdellid leeches have colourless blood. The…
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circulatory system
Blood
The green chlorocruorins are also iron–porphyrin pigments and are found in the blood of a number of families of marine polychaete worms. There is a close resemblance between chlorocruorin and hemoglobin molecules, and a number of species of a genus, such as those of Serpula, contain both,…
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The green chlorocruorins are also iron–porphyrin pigments and are found in the blood of a number of families of marine polychaete worms. There is a close resemblance between chlorocruorin and hemoglobin molecules, and a number of species of a genus, such as those of Serpula, contain both,…
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