Cytological observations on the blood and hemopoietic tissue in the crab, Callinectes sapidus. I. The fine structure of hemocytes from intermolt animals.

A fine structural analysis of hemocytes recovered from the pericardial sinus of the blue crab (Callinectes sapidus) demonstrates that hyaline cells, intermediate cells, and granulocytes are present in the hemolymph. A detailed consideration of their shared and differing cytological features suggests that the various blood cells represent different stages of cytogenesis along a common or single path of cellular differentiation. The potential functional complexity of the hemocytes is attested to by the occurrence within their cytoplasm of three and/or possibly four morphologically distinct types of inclusion bodies, and other membrane-bounded compartments (e.g., lysosome-like structures, autophagic vacuoles, peroxisome-like bodies) whose function is unknown. Preliminary examination of the well-developed Golgi organelle in the intermediate cells and granulocytes indicates its probable participation in the elaboration of the inclusion bodies; however, the details of its role in granulogenesis and in the known plurifunctional capacities of these cells remain obscure.