Classification, Based on Autonomous Fluorescence, of the Blood Cells of Several Ascidians that Contain High Levels of Vanadium

Ascidians are known to have the unique ability to accumulate vanadium in their blood cells. Classification of the various types of blood is, however, the subject of some controversy. In the present study we found that the various types of blood cell can be classified on the basis of their autonomous fluorescence upon excitation with blue‐violet light. This method was of particular practical value in the classification of the vacuolated cells that account for about 80% of the total population of cells and are distinguished by their ability to accumulate vanadium.