The Dying Observation And Classification On Haemocytes Of Familiar Shrimps And Crabs

Diseases are critical barriers to the continuous and healthy development of shrimp and crab aquiculture, so diseases control is nowadays a priority. The defence mechanisms of crustaceans are poorly understood, but knowledge of which is a prerequisite for the development of diseases control. Shrimps and crabs do not possess an adaptive immune system as vertebrates do. The defence systems of shrimps and crabs are often described as based only in innate immunity, which includes the cellular immunity and lymph immunity.Haemocytes play important roles in the immune activities of shrimps and crabs, such as clotting, phagocytose, encapsulated, formation of nodus and healing of wound. By now, the defence mechanisms of haemocytes in shrimps and crabs have not been well understood. A universal classification scheme of the circulating haemocytes is a prerequisite for comparative functional studies, but it is still not available for haemocytes of shrimps and crabs. The various methods and criterias of haemocyte classification lead to a multiplication of names, making comparisons very difficult.By the dying tests of haemocytes in 12 species of shrimps and crabs which are important in aquaculture, we found out a reliable and simple dying protocol suitable for the dying of haemocytes in these shrimps and crabs. The 12 species are Macrobrachium nipponense, Macrobrachium rosenbergii, Penaeus vannamei, Penaeus monodon, Penaeus japonicus, Metapenaeus ensis, Procambarus clarkii, Eriochier sinensis, Scylla serrata, Charybdis feriata , Portunus trituberculatus and Oratosquilla kempi.We observed the dying characters of haemocytes in 12 species of shrimp and crab by light microscope(LM), and observed the ultrastruture of haemocytes in Macrobrachium rosenbergii by transmission electron microscope(EM). Two criterias can be obviously observed in EM and LM both: the amount and relative size of granules; the nucleolus/plasm (N/P) ratio of haemocytes. According to these criterias, haemocytes of shrimps and crabs were divided into hyaline cell (HC) , semigranular cell (SGC) ,and granular cell (GO .We observed the morphology of haemocytes in 12 species of shrimps and crabs by LM, measured the size of haemocytes, made differential counts of the percentage of three kinds of haemocytes and the total haemocyte counts (THC) .The size of haemocytes in the 12 species of shrimps and crabs varies greatly. The long axes ranges from 5um to 20 urn, and short axes ranges from 4urn to 14um. Considering one kind of shrimps or crabs, the size of haemocytes has a rule: HC GC.Considering the percentage of three kinds of haemocytes, the GC is the major type of haemocytes in Penaeus vannamei, Macrobrachiwn nipponense and Oratosquilla kempi. SGC is the major type of haemocytes in other shrimps and crabs.The HC takes the lowest percentage of three kinds of haemocytes in all observed shrimps and crabs. The THC of 12 species of shrimp and crab range from 0.4 X 107/ml to 2.5 X 107/ml.The dying protocol used in this thesis has been successfully used in haemocytes dying of 12 species of shrimps and crabs, it suggested that this dying protocol should be useful to haemocytes dying in other crustaceans. The data of haemocytes in 12 species of shrimps and crabs provided the fundation for the immunological researches of these shrimps and crabs.