Visit Science News to read breaking news about the latest discoveries in science, health, the environment, technology and more.

Please Join Us On Facebook and Twitter

Tuesday, 30 July 2019

What are the different colors of blood in the animal kingdom?

Biological fluid tirelessly traversing our arteries and veins, we are used to the symbolic color of blood: red. It is the color of the blood in humans and in vertebrates, so much so that we would be tempted to believe that it would be the only color that it can take. However, this is not the case; on Earth, the blood actually comes in five different colors.

About 6 liters for a man and 5 liters for a woman: this is the amount of blood that runs through our body permanently in a network of blood vessels with a length of 100'000 km. He perfuses all the organic tissues in order to bring them oxygen. It consists of red blood cells (or erythrocytes, Greek erythros for red) which carry a very particular protein: hemoglobin.

Hemoglobin is more precisely a metalloprotein because it contains iron. The iron atoms are capable of fixing oxygen, and this bond between iron and oxygen gives oxyhemoglobin. Oxyhemoglobin thus appears red under the oxidation of the iron contained in hemoglobin. This is why the blood of most vertebrates is red in color. However, not all animals have blood based on hemoglobin.

Hemoglobin is a metalloprotein containing four iron atoms to fix oxygen. The oxidation of iron gives it its red color. Credits: aboutkidshealth

Some species of beetles, ascidians and holothurians, have vanadocytes: cells very rich in vanadium (concentration 100 times higher than in seawater) acting as blood cells. Inside vanadocytes are vanabine, a vanadium-fixing metalloprotein; it is also called hemovanadine. Vanabine does not fix oxygen, so its role is still unknown. But it is she who gives a pale green and yellow color to the haemolymph of these animals.

Vanabine is a metalloprotein that binds vanadium. The oxygenated form, hemovanadine, confers a green or yellow color to certain species of ascidians ( Didemnum soft on the picture). Credits: Bernard Dupont

In annelids (marine worms, leeches, etc.), a large amount of chlorocruorine is found in the blood plasma (and not in the blood cells themselves). It is a metalloprotein whose affinity with oxygen is very low. When oxidized, it appears green in normal plasma concentrations; and pale red in high plasma concentrations.

Spiders, crustaceans, octopus and squid, as well as some species of molluscs, have a haemolymph (circulatory liquid of arthropods) containing hemocyanin. It is a metalloprotein containing copper (two Cu + cuprous cations ) to bind oxygen. The oxygenated form of hemocyanin is blue. This is why the hemolymph of these invertebrates appears blue.

Hemocyanin is a metalloprotein that binds oxygen through cuprous ions. Its oxygenated form takes on a blue color. This is particularly noticeable in the horseshoe crab. Credits: Mark Thiessen

The hemolymph of brachiopods and certain marine worms is made up of hemerythrin, an oligomeric metalloprotein made of iron that transports oxygen. Unlike other ferric hemoproteins, hemerythrin binds oxygen by forming a hydroperoxide complex ROOH. When the hemerythrin fixes the oxygen, it takes on a purplish purple / pink color. The hemolymph of these invertebrates appears purple.


    Most traditional methods of roots and herbs today have been scientifically proven to cure almost all drugs resistant diseases without after effect.
    It worked for me years ago when I was depressed with herpes. After trying numerous other methods, It was actually an old Ibo lady who brought to my notice the healing effect of natural medicines. She too was permanently cured from HERPES long time ago through Dr Utu @ "" who among few, specialises in African roots and herbs for medicinal cure. Apparently roots and herbs have well been known as effective key treatment for herpes. She introduced me to Dr Utu who till date remain my savior, and he truly cleared my doubt. After taking his medication on the fourth week, I contacted him again who asked me to go for test and I was negative. From then till now I do my normal business no outbreak. I may not be a herbal fan but it definitely worked for me!


    I am from USA i was diagnosed with HSV TPYE 2 while I was pregnant .I cried for days. I was devastated and looking up info on it just made it worse. I don't know how long I have had it for. I don't know if my partner has it or if he was the one who transferred it to me. I had one outbreak while pregnant. That's how I found out I had the virus. I started taking and antiviral and took it everyday twice a day to make sure I wasn't able to get an outbreak. I debated whether I wanted to have my daughter natural or c- section. I was terrified. Stress wasn't helping my situation. I ended up having her natural and she is a beautiful healthy 2 month old baby girl. I try not to think about me having the virus because of my depression i couldn't. so I have to focus more on how to get rid of HSV TPYE 2 because i don't want anything to happen to my daughter and thank God she was born fine. i visited different hospital but they gave me list of drugs like acyclovir, Zovirax, and (valacyclovir)Valtrex without without get rid of my virus. one day i decide to surf the internet for cure so i  saw a testimony  total cure of HERPES by Dr. EHIAGWINA with  NATURAL HERBS so  i pick up the email Address: and contact he an hour later he reply explain to me how am going to get the herbs and how am going to use it  to cure my virus i give a try believe me it work perfectly i used it within seven days now am tested negative i am free from the virus thanks Doc. for so many passing through this contact Dr. EHIAGWINA to help you get rid of the  virus. here is his email address:  you can also call or add him on whats app +2348162084504 He can as well cure so many diseases like...........

    1. ALS

    2. HPV


    4. CANCER

    5. HIV/AIDS

    6. BREAST AND PENIS ENLARGEMENT and others diseases i can't remember now.Thanks Doc am so happy today

  3. Just wanna say a big thank you patrice cythia for introducing me to Dr Idedia the great HERBALIST that helped me prepare home remedies that cured my herpes simplex virus (HSV1&2)
    I was infected with herpes for the past two years and i was not happy all day so i was desperate to get a cure so that i can live normal and get healthy.One day i was less busy so i decided to make latest research on herpes  cure  and i found a site were everyone was talking about Dr Idedia and has ability to cure Herpes, HIV, HPV, Cancer, ALS, COPD, Anthrax, genital wart, cold sore, Arthritis skin tag and all manners of diseases and virus.So i discussed with cythia and she explained to me that its very easy working with Dr Idedia  so i contacted Dr Idedia via email and he helped me just as he has helped others now I am  now cured from herpes am very happy now.and i can also assure you that he can also help you. so if you need the service of DR Idedia kindly contact him or whatsapp +2349074505296.
    visit his websites Or Or 

  4. Thank you so much as you have been willing to share information with us. We will forever admire all you have done here because you have made my work as easy as ABC. geckos for sale

  5. God bless Doctor abaka for helping me cure my herpes disease. Brethren, i have suffered herpes for a long period of time, i have tried so many remedy, but known seems to work. But i had contact with a herbal doctor who i saw so many people testifying on how they were all cured of their various disease and viruses by this doctor. So i explained my entire problem to him, and he promised to cure me. So i gave him all benefit of doubt, and behold he prepared the herbal mixture, and send it to me in my country. Today, i am proud to say i am herpes free, and my life has been restored to normal. So in case you are out there suffering from herpes and other diseases or virus, i want to tell you to quickly contact: abaka for your cure. His email is or call +2349063230051.