en Biology & physiology Biology & physiology پژوهشي Orginal research papers <span lang="TR" style="font-size:11.0pt"><span calibri="" style="font-family:"><span style="color:black">The aim of this study was to determine the hemocyte type of medicinal leeches, <i>Hirudo sulukii </i>and <i>H. verbana</i>. </span></span></span><span lang="TR" style="font-size:11.0pt"><span calibri="" style="font-family:"><span style="color:black">It was also determined the fractions of hemolymph proteins in these leech species. According to the analyses, </span></span></span><span lang="TR" style="font-size:11.0pt"><span calibri="" style="font-family:"><span style="color:black">four types of hemocyte (prohemocyte, plasmatocyte, granulocyte, and eleocyte) were detected in two species. The prohemocytes have large nuclei, and their cytoplasm occupies a small area. The plasmotocytes are the most abundant hemocyte type. They are polymorphic cells and are found together as aggregations. The granulocytes are generally rounded in shape and typically have large granules in their cytoplasm. The eleocytes are the least found cells in hemolymph and have few granules in their cytoplasm. The areas of hemocyte types did not differ between the two species. Using polyacrilamid disc gel electrophoresis, it was determined that the hemolymph proteins of <i>H. verbana</i> were separated into 11 fractions or fraction groups. On the other hand, they were separated into 10 fractions or fraction groups<i> </i>in<i> H. sulukii</i>. In addition to qualitative differences, there were important quantitative differences between electropherograms of the two leech species. Therefore, these findings made a contribution to studies considering <i>Hirudo sulukii</i> as a new species different from <i>Hirudo verbana</i>.</span></span></span> Medicinal leech, Hirudo sulukii, Hirudo verbana, Hemocyte, Hemolymph 555 564 http://jifro.ir/browse.php?a_code=A-10-4745-1&slc_lang=en&sid=1 Z. Kürtüral zalihe-14@hotmail.com 100319475328460056748 100319475328460056748 No Ege University, Science Faculty, Biology Department, Zoology Section 35100 Bornova, Izmir, Turkey Ö. Çakıcı ozlem.cakici@ege.edu.tr 100319475328460056749 100319475328460056749 Yes Ege University, Science Faculty, Biology Department, Zoology Section 35100 Bornova, Izmir, Turkey