Microanatomical study of the spleen in beluga (Huso huso)

Objective: The aim of this study was histological survey on spleen of 15-month old beluga (Huso huso). Method & Materials: In this study, six 15-month old Huso huso underwent histological studies. At first the fish were autopsized and spleen specimens were fixated in 10% formalin. Fixed tissue were dehydrated in graded ethanol solutions, cleared in xylene, embedded in paraffin Then 6 μm sections were prepared and stained with Hematoxylin – eosin (H&E) method. The specimens were analyzed under a light microscope. Results & Conclusion: This study showed that spleen was covered with a thin layer of connective tissue. External surface of spleen was covered by simple squamous cells. Parenchyma of spleen had a large amount of lymphatic nodules that formed the white pulps. The central articles were located in the centre of the nodules. There were red pulps, contained a great number of RBCs with nodules and lymphatic cells, among lymphatic nodules. In the middle of spleen, the pancreas was evident. In extremities of spleen lymphatic nodules were not seen but in some spots splenic cords and in some other spots lymphatic cells along with RBCs were observed. It was shown that the spleen of Huso huso like those of other fish was rich in lymphatic cells and RBCs. In contrary, splenic nodules in the body and first part of left and right lobes were evident that like those of white pulp of mammalians.