Meeting Abstract

P3.139  Wednesday, Jan. 6  Morphology of the heart-kidney complex in Megathura crenulata, the giant keyhole limpet: the hunt for hematopoietic tissue and HCN storage sites MARTIN, G.G.; MARTIN, A.M.*; WATANABE, K.; Occidental College, Los Angeles; Occidental College, Los Angeles; Occidental College, Los Angeles gmartin@oxy.edu

The intricate anatomy of the heart and kidney complex in prosobranch gastropods has been investigated in several species. In vetigastropods, the left kidney is highly reduced and its function is unclear although it may be involved with ion, pH, and water balance. The right kidney is enlarged and wraps around most organs in the body creating the largest cavity in the body. This space is continuous with the pericardium which receives an ultrafiltrate that passes through the auricles via pericardial glands. The heart and kidney are therefore involved with filtration and excretion and both organs release fluid into the mantle cavity. We describe the morphology of these tissues in the giant keyhole limpet, Megathura crenulata. Our interest is in specialized regions within this complex which are possibly involved with hematopoesis and the storage of the respiratory pigment KLH (keyhole limpet hemocyanin). Hemocytes are important for immune defense reactions and KLH is the protein of commercial value extracted from limpets in culture. KLH shows promise in the treatment of cancer and allergy. Non-lethal bleedings of cultured limpets remove up to 20% of the body weight. The body weight returns to original levels within 12 hours and by 24 hours KLH levels in the blood are back to normal. The goal of this poster is to describe the anatomy, histology and ultrastructure of regions of this complex highlighting areas where it has been proposed and where we have found sites of hematopoiesis and KLH storage.