What Chemical Element Gives the Blood of a Lobster and Octopus a Bluish Tint?

The blood of crustaceans like lobsters, octopuses, snails, spiders, and other insects contains copper, which is used to carry oxygen. Hemocyanin describes this substance.

The oxygenation process turns copper from its original colourless state to a bluish-green hue. Vertebrates, including humans, have blood that is rich in iron.

What Chemical Element Gives the Blood of a Lobster and Octopus a Bluish Tint?

Why is Lobster Blood Colorless Until Exposed to Oxygen?

Even though their blood is full of the pigment hemocyanin, the blood of lobsters newly dragged out from a trap at the ‘ocean’ bottom will seem colourless.

It’s true that oxygen is scarce near the ‘ocean’s’ bottom, therefore this statement makes sense. Because of the high oxygen titer near the surface.

Lobsters maintained in floating lobster totes or in shallow lobster pounds will have oxygen charged hemocyanin.

There are many species, both little and huge, that consume oxygen, therefore its supply decreases fast as one descends to the ocean floor.

Low oxygen levels do not harm lobsters as much as high CO2 levels. They are more motivated to breathe in order to exhale the CO2 that is produced during breathing.

They thrive in colder climates because low temperatures result in lower O2 use. They migrate offshore to deeper colder water as the summer heats the inshore water up.

At 15 degrees Celsius (59 degrees Fahrenheit), their oxygen requirements are minimal. If they are housed at the surface in a keeper.

They will require a higher oxygen concentration, and their hemocyanin will be fortified to meet this demand.

Hemocyanin is a hexameric protein, with distinct components that load O2 under conditions of surface temperatures and behave differently at the bottom ocean temperatures.

Arthropods Blood Uses Different Protein Called Hemocyanin

Hemocyanin, a different protein, binds oxygen in the blood of these insects. Due to the involvement of a copper atom in the binding process rather than an iron atom.

Oxygenated blood appears blue and deoxygenated blood appears nearly colourless. Horseshoe crab blood contains a molecule called coagulogen.

Which may detect bacterial contamination at extremely low concentrations, completely independently of the colour.

As seen in the PBS documentary Crash, corporations actively seek out horseshoe crabs and bleed them to death since their blood is so valuable in drug testing.


Hemocyanin, which includes copper, gives lobsters’ blood its distinctive blue colour, much as it does in snails and spiders.

Hemoglobin, an iron-rich molecule, gives the blood of vertebrates and other animals its distinctive red colour.

For both liver and pancreatic functions, lobsters rely on a single organ, the green hepatopancreas (also known as the tomalley by chefs).