Hemovanadin

Hemovanadin is a pale green vanabin protein found in the blood cells, called vanadocytes, of ascidians (sea squirts) and other organisms. It is one of the few known vanadium-containing proteins.

The German chemist Martin Henze first detected vanadium in ascidians (sea squirts) in 1911. Unlike hemocyanin and hemoglobin, hemovanadin is not an oxygen carrier.