| Shellfish aquaculture is the pillar industry of the marine economy in our country. Because the extensive death of the shellfish takes place occasionally in recent years, the disease has already become the choke point of development of shellfish aquaculture. The immune system of shellfish plays an extremely important role in defending the disease. So the research in immunology of shellfish is particularly important for understanding the disease in shellfish cultivating and the mechanism of the shellfish immune defense system deeply. In hope of knowing about the defending system of shellfish and try to improve the defense capability of the shellfish from the immunology angle, we had following experiments, including the classification of the shellfish haemocytes, cellular immune function research on shellfish, properties of hemagglutinin of the ark shell Scapharca subcrenata, effect of copper on the lysosome membrane of scallop, immune modulation to the cytological and humoral immunological activities of the scallop by some oligosaccharides and amylose, and comparison of the immune function of the triploid and diploid scallop.The form, structure and function of the blood cells should be clearly understood, which is very essential for the further research in defending mechanism of the immune system, because the blood cell plays an important role in defending the pathogen. Classification of the haemocytes of scallop Chlamys farreri and ark shell Scapharca subcrenata were carried out in this study by FCM and Wright's staining. It was revealed that four groups of haemocytes were present in ark shell Scapharca subcrenata: (1) Erythrocyte with the size of 18.4+0.97μm is dominant cell in the blood; (2) Hyaline leucocyte with the size of 5.63?.49μ.m possesses a heavily stained nucleus but no granules in the cytoplasm when treated by wright's staining; (3) Granulocyte which has granules in the cytoplasm, could be divided into two groups according to the staining of granules, one is orange, 8?.06μm, the other is blue, 6.3+1.253m; (4) The fourth group has a large nucleus, 5.17?.69um. Two kinds of haemocytes were mainly found in scallop Chlamys farreri: (1) Hyaline leucocyte with the size of 7.3?.97μm, which has no granules in the cytoplasm underobservation with optical microscope; (2) Granulocyte with the size of 10.24?.64jim, which has granules in the cytoplasm.The in vitro phagocytosis property of scallop Chlamys farreri and ark shell Scapharca subcrenata were studied here. It showed that: (1) In Scapharca subcrenata, granulocyte, hyaline leucocyte, and erythrocyte could phagocytize Candida albicans cells in vitro. The optimal temperature of phagocytosis was 30?C, and the phagocytic rate was 62.11%. When the ark shell was challenged with Vibrio anguillirum, the phagocytic activity of the haemocytes increased markedly in comparison with those treated with saline or sterilized Vibrio anguillirum. (2) In Chlamys farreri, the haemocytes could also phagocytize Candida albicans cells in vitro. Some Candida albicans cells was adhered to the membrane of the haemocytes, and there was a sunken at the interface on the membrane, some was phagocytized into the haemocytes through amoeban locomotion. The optimal temperature of phagocytosis was 20?C, and the phagocytic rate was 38.05%.Reactive oxygens of Chlamys farreri haemocytes were detected by modified NET assay, the color of NBT negtive haemocytes was rose pink, and no dark blue formazan deposit granules was observed in the haemocytes. In NBT positive haemocytes, formazan deposit granules could be observed in the rose pink haemocytes under optical microscope. It was concluded that reactive oxygen intermediates of Chlamys farreri could be detected under natural condition, and the NBT positivity rate was 20-35%.Three endoenzymes, alkaline phosphatase (ALP), peroxidase (POD), phenoloxidase (PO), associated with haemocyte in three kinds of scallops, Chlamys farreri, Patinopecten yessoensis and Argopecten irradians were researched by immunocytochemical localization meth...
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