Hemocyte types and some plasmatic properties of two edible crabs Cancer borealis and Cancer pagurus

Cancer pagurus and Cancer borealis and are edible crabs produced by economically relevant aquaculture. In this study the hemocytes and some plasmatic parameters of Cancer borealis and Cancer pagurus were examined. The cell features of the hemocytes were observed using light and scanning electron microscopy (SEM). Granulocytes, semigranulocytes and hyalinocytes were mainly identified on the basis of size, presence/absence and quantity of the cytoplasmic granules and the nucleus-to-citoplasma (N/C) ratio. SEM observations were useful for disclosing the surface features of these cells, and the same characteristics were found in both crab species. A smooth surface distinguishes elongated hyalinocytes and a rough texture the irregular surface of spherical/ovoid granular cells. Total (THC) and differential hemocyte counts (DHC) were performed, and the differences between the two crab species were disclosed. Also we were valuated pH and osmolarity values, agglutinating activity and different protein contents of the hemolymph