Anemia and its mechanism in goldfish Carassius auratus infected with Trypanosoma danilewskyi

Abstract

Trypanosoma danilewskyi Laveran & Mesnil, 1904 caused anemia in goldfish Carassius auratus . The severity of the anemia was associated with high parasitemia. At least 2 factors are responsible for the anemia; hemolysin: a secretory/excretory product of living trypanosomes which lyses red blood cells (rbc) in the absence of antibody (in vitro study) and hemodilution (in vivo study). No significant hemolysis was detected when rbc were added to sonicated trypanosomes. The hemolysis and hemodilution were correlated with numbers of parasites. Secretion/excretion of hemolysin by living trypanosomes was associated with declining pH in the incubation medium but the pH itself was not involved in hemolysis.