Abstract
A study was made on the hemocyte morphology of freshwater snails Physa aorta and Bellamaya bengalensis. The hcmolymph directly obtained from the heart was allowed to settle for 30 minutes before fixation and staining. Both snail species showed two basic types of hemocytes known as spreading hcmocytes and round hemocytes. Light microscopy of these hcmocytes revealed behavioural distinctions. In both the snails studied, the spreading hemocytes predominates. Mean percentage of these cells constitutes 90.51+3.71 and 93.38+2.03 for P. acuta and B. &rigatonis respectively. Similar values for round hcmocytes were 6.62+1.22 and 9.48+1.01 percent. Majority of the spreading hemocytes were mononucleated. However, less than 2% of the total blood cells were binucleated or multinucleated, with unequal nuclei termed as m9ther nucleus and daughter nucleus. Round hemocytcs were always mononucleated. The mean size of the tflononucleated spreading hcmocytes was 1378.42+578.08 and 1745.26+990.39 fumy, while that of the binucleated cells•was 1843+ 1171 and 3202.0+ 164679 (am) for P. aorta and B. bengaknsis. The nucleus of spreading hemocyte was rounded to oval, kidney shaped or lobulated. Only spreading hcmocytes produced filopodia and pseudopodia in almost all directions and were capable of exhibiting rapid changes in shape, but no net motion. The number of pseudopodia produced by Treading hcmocytes lie between 9-27 with an average value of 17.47+5.77 and 13.+4.89 for P. acuta and B. bengalensis respectively. Maximum average length of pseudopodia of a single spread hemocyte was 327.37+ 143.67um and 226.84+95.6811m for P. aorta and B. bengalensia. The round hemocytes were characterized by the presence of more of less circular or wcavy boundry, and no pseudopodia. They also posses comparatively hyaline (clear) cytoplasm alongwith few granules and vacoulcs of various sizes. Plc mean area occupied by round hemocytes was 416.0+140.22 and 950.0±-928.10 (urn)4 for P. acuta and B. bengalensis. with a typical rounded to oval nucleus. Only spreading hcmocytes fuse with one another to form synctia but round hemocytcs did not fuse either with each ot.hcr or with spreading hemocytes. However, fusion among spreading hemocytes was reversible. The present findings are discussed in the light of available studies on the molluscan blood in general and gastropod hemolymph in particular
AKHTAR TANVEER . (1991) STUDIES ON THE MORPHOLOGY OF HEMOCYTES OF PHYSA ACUTA AND BELLAMAYA BENGALENSIS, Punjab University Journal of Zoology, Volume 6, Issue 1.
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