| Popis: |
Light, transmission and scanning electron microscopical studies were carried out to characterize the hemocytes of the scallop Chlamys farreri (Jones & Preston). Five types of hemocytes were recognized: type 1 small hyalinocytes (2.44 +/- 0.11 mu m, 45% to 50%), type 2 large hyalinocytes (4.83 +/- 0.28 mu m, 15-20%), type 3 small granulocytes (4.07 +/- 0.15 mu m, 15% to 20%), type 4 medium granulocytes (7.20 +/- 0.26 mu m, 20-25%) and type 5 large granulocytes (13.87 +/- 0.73 mu m, 3% to 5%). Granulocytes showed larger sizes and smaller N/C ratios than hyalinocytes. The mean hemocyte concentration was about (3.03 +/- 0.11) x 10(7) cells mL(-1). Among hemocytes, 42.6% are granular cells and 57.4% are agranular cells. These gave a relatively systematic classification scheme for hemocytes of Chlamys farreri. Three kinds of granules were identified: high electron-dense granules, low electron-dense granules and medium electron-dense granules based on TEM studies. Both granulocytes and hyalinocytes showed phagocytic response to the two strains of bacteria, E. coli and Rickettsia-like organisms. The phagocytic ability of granulocyte was significantly higher (30% to 40%) than that of hyalinocyte (4.8% to 14%). |
