Do Fish Have Blood and Hearts, What Color Is Fish Blood, and Why Don’t Fish In Stores Have Blood?

Fish do have blood, and it is red.

Other cold-blooded animals, like amphibians and reptiles, also have red blood.

Fish have a circulatory system with blood and a heart as the pump just like that of humans, and just like that of humans, fish blood is red because it contains hemoglobin, the iron compound that carries oxygen.

If a fish is fresh and is cut near major vessels, you will see blood.

In muscle tissue, which becomes fillets, the vessels are so small that the blood may not be evident, or if the fish is not fresh, the blood may have coagulated or collected in one part of the body.

Fish from the fish market may have already been gutted and beheaded and so may be drained of most blood.

Even so, you might see blood around the spine, because a major blood vessel goes right under the arches of the vertebral column.


  1. Jacob says

    Fact: fish blood is not red, it is blue, just like any other living animal, what turns it red is oxygen, if u bleed in water, notice it is blue, because there is no oxygen, but out water, the oxygen turns it red. So fact is, the blood is blue

  2. DenHardy says

    Blood is not blue, I’m afraid that’s a bit of a myth and not at all factual, the air that we all breathe in true fact contains oxygen and this oxygen is transported around the body in our blood this means our blood is already oxygenated regardless of exposure to external oxygen sources. The arteries contain bright red blood as they carry the oxygen to vital organs and body locations, whereas veins carry significantly lower amounts of oxygenated than the arterial blood thus resulting a much darker however still red colour, that’s a real fact for you.

  3. Judith Brydon says

    Why do we say that Royalty has ‘Blue Blood’ when I was little I saw that the blood looked blue in my veins so I beleived I was also from Royalty

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