Turkish Journal of Fisheries and Aquatic Sciences
2017, Vol 17, Num, 2 (Pages: 231-243)
Ultrastructure of Haemocytes of the Freshwater Crab Travancoriana schirnerae
2 Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India 560 029 DOI : 10.4194/1303-2712-v17_2_01 Viewed : 3888 - Downloaded : 3401 The light and ultrastructural observations on haemocyte profile of the freshwater crab Travancoriana schirnerae demonstrated three cell types: agranulocyte, granulocyte I and granulocyte II. Agranulocytes are the smallest of the haemocyte types, comprised 38% of the haemocytes, devoid of granules and showed high nucleoprotoplasmic ratio. Their cytoplasm contained numerous free ribosomes, vesicles of smooth endoplasmic reticulum, few mitochondria with parallel cristae and vacuoles. Granulocytes I (37%) are the largest of the haemocyte types, characterized by the presence of numerous granules (26 to 61) of varying size, shape and densities and organelles like mitochondria, free ribosomes and peripheral vacuoles and displayed low nucleoprotoplasmic ratio. Granulocytes II (25%) contained large electron dense granules (10 to 23) and organelles like free ribosomes and vacuoles and showed intermediate nucleoprotoplasmic ratio. Unlike granulocytes, agranulocytes exhibited prominent pseudopodial projections suggesting a phagocytory function. This study revealed the unusual occurrence of a binucleate agranulocyte and a rare phenomenon called clasmatosis of granulocyte II, wherein part of the cell fragments off along with cytoplasmic contents devoid of nucleus. Keywords : Agranulocyte, Clasmatosis, Granulocyte, Nucleoprotoplasmic ratio