Studies on the erythrocytes of larval and adult lampreys (Lampetra fluviatilis)

The erythrocytes of larval and adult Lampetra fluviatilis were examined in suspensions of whole blood, solutions of various ionic strengths, scanning electron photomicrographs and air dried smears. Although a wide range of shapes were observed in hyper- and hypotonic solutions, the cells in whole blood and isotonic solutions were predominantly biconcave with an eccentric nucleus. The biconcave shape was also seen in scanning electron photomicrographs of erythrocytes fixed with glutaraldehyde in lamprey Ringer. The mean diameter of larval and adult cells in whole blood suspensions was 11.2 and 11.6 μm respectively. Although in air dried smears the areas of the larval and adult erythrocytes were virtually identical, the erythrocyte nuclear area was markedly higher in ammocoetes with only a small amount of overlap between the values obtained for the two stages in the life cycle.