Splenic Erythropoiesis and Thrombopoiesis in Elasmobranchs: An Ultrastructural Study

Zapata, A. 1980. Splenic erythropoiesis and thrombopoiesis in elasmobranchs: an ultrastructural study. (Department of Anatomy, School of Medicine, University of California, Los Angeles, U.S.A.) — Acta zool. (Stockh.) 61(1): 59–64. Erythropoiesis and thrombopoiesis occured in splenic red pulp of Raja clavata and Torpedo marmorata (Elasmobranchs, Batoidea). Both processes are intravascular and later developmental stages of erythrocytes can be also found in peripheral blood. Stages of erythropoiesis showed a successive increase of nuclear condensed chromatin and cytoplasmic hemoglobin content. Aspects of cytoplasmic granules suggested the existence of two thrombocytic precursors in these elasmobranchs. The importance of hemopoietic microenvironments for blood formation is emphasized in this work.