Presence of blood cells in rainbow trout milt

Abstract

Blood cells were found in milt, collected at the end of spawning, of 2-years-old rainbow trout. Among blood cells, lymphoid cells dominated, followed by erythrocytes and phagocytic cells. Lymphoid cells were mainly present in clusters rather than as individual cells. Erythrocytes usually accompanied lymphoid cells. At present it is not clear if the presence of blood cells in milt is related to normal physiology of semen or rather to milt contamination.