| This paper is a comparative study in functional morphology excretory organs of 6 species of economical aquatic crustaceans. They are antennary glands of Penaeus monodon, Macrobrachium nipponense, Exopalaemon carinicanda,Holhuis, Panulirus homarus, Procambarus clarki and maxillary gland of Oratosquilla oratorio. There is no similar undergoing study in our country yet. The study of above applied areas, the exploring of basic theory of crustacean biology and disclosing the fundamental mechanism and adaptability of osmoregulation and excretion of aquatic crustaceans in different aquatic environment (chiefly the half-salty water ) during their production. Now we promote our findings as follow:1 .The maxillary gland and antennal gland are consist of same 3 parts, they are coelomosac, labyrinth and nephridial canal, the rear two parts make the canal portion.2.The chief site of excretion (especially the filter role) is coelomosac and its podocytes,and the osmoregulatory site in excretory organs is the canal portion. Because the osmotic pressure in the freshwater species isgreatly different with the osmotic pressure in their environment, while it's almost the same to those seawater species. So in freshwater species, the structure related to osmoregulation in canal portion of excretory organ such as microvilli, basolateral infoldings, mitochondria and so on, are more abundant and more developed than those in seawater species. So do the structures related to excretion because the environment of freshwater species is more complicated even heavily polluted. These specified the unity of structure and function in crustaceans. For crustaceans, feature are chiefly the result of long term adaptibility to their environment, and it's no close relation to evolution. 3.The filtration barriers of excretion in developed or less developed crustaceans are consist of podocytes (their foot processes), slit membrane, basal lamina and the pores of endothelia cells. 99 percent of ingredients of blood through these barriers into coelomosac and become the initiative filtrate solution. From this solution, the podocytes reabsorbed, digested and utilized glucose and part of proteins, peptides and amino acids. The rest of proteins, peptides and amino acids are reabsorbed by podocytes and labyrinth cells, then become formed bodies and secreted into urinary space again and flow with the urine. These nutritions are digested in formed bodies and then reabsorbed and utilized by cells of nephridial canal. At the same time, the labyrinth cells reabsorbed a small part of ions and water through isomostic wayfrom initiative filtrate solution,then the most of ions and water of this solution are reabsorbed by the cells of nephridial canal through active transport. And the cells of nephridial canal secreted H+ into urine to regulation its pH. At last, the waste of metabolism and hetero-materials such as toxical materials which are invaded into the organisms accidentally are excreted with the urine. Then the role of holding organisms' homeostasis of excretory organs is accomplished. 4.We observed septate junctions in adjacent podocytes or their processes in first time. We also observed a new kind of junction which is different from all reported junctions in adjacent podocytes or their processes of Macrobrachium nipponense and Exopalaemon carinicanda, Holthuis - two species of Palaemonidae. Its characteristic feature is the two membranes are connected by two rows of granules which are staggered each other. Button-shaped and septate junctions are usual observed in adjacent podocytes or their processes. And adjacent cells of canal portions are connected by an intermediate junction in apical and followed a septate junction, sometimes also followed a gap junction. These confirmed again that there is not tight junction in invertebrate but intermediate junctions and septate junctions. Those junctions in canal portions can prevent macromolecules invading into urinary space from blood space through those large intercellular space of cells of ca...
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