Effects Of Calcium Concentration On The Photoreceptor In The Penaeus Monodon Fabriciu

The Influence of Light Adaptation on the Ultrastructure of the Photoreceptor in Penaeus monodon FabriciuThe form and the fine structure of compound eyes in Penaeus monodon Fabriciuwere studied by e lectron microscopy. The result show the ommatida that form the compound eye in Penaeus monodon Fabriciu were composed of cornea, four cone cells, eight retinular cells and some pigment cells. During light adaptat ion the arrangement of microvillus in the rhabdom was in disorder, and the diameter of rhabdom was reduced. At the same adaptation the area of the perirhabdomal vacuole was reduced and the number of the multi vesicular body was increased. Besides that the d i str i but i on and the amount of the p i gment granule, the lamellar body were influenced by light adaptation. During the dark adaptation the result contrasted on that of light adaptation. The result showed that different Light adaptation influent the Ultrastructure of the Photoreceptor.Effects of Different Calcium Concentration on Ca2+ in Ca2* - Sequester ing Organelles of Photoreceptor Cell in Penaeus monodon FabriciuBy the combined oxalate-pyroantimonate technique, We observed the subcellular distribution of calcium in the photoreceptor cells of Penaeus monodon Fabricius, by changing the extracellular calcium concentration. The result showed that, in vitro, in presence of 50mmol/l, the quantity of calcium antimonate deposit in the multivesicular bodies, pigment and lamellar body were more than that of photoreceptor incubated in lower calcium solution, which contained 50mmol/l EGTA. In higher calcium solution, we ecu Id not f i nd the depos i t in the mitochondr ia, but in lower calcium solution, there was a little deposit in the mitochondria. Theresult of deposit distribution in the physiological saline was the same as lower calcium solution.Effects of Different Calcium Concentration on the Fine Structure of dark adapted Photoreceptors in Penaeus monodon FabriciuThe relationship of extracellular Ca concentration and the fine structure of dark -adapted photoreceptors in the Penaeus monodon Fabr iciu was studied with electron microscopy. The result showed that in vitro, in presence of 50mmol/l calcium, the diameter of rhabdoms and the dimension of perirhabdomal vacuoles extremely reduced than that of photoreceptor incubated in physiological saline. The dimension of the cytoplasm, located around the rhabdom, increased in the high extracellular Ca solution. Meanwhile, like the morphological structure of the retinular cells during light adaptation, the diameter and number of multivesicular bodies reduced, while the number of lamellar bodies increased in the retinular. The pigment granules were more and located in distol part of the retinular cell. However, in presence of 50 mmol/l EGTA, the diameter of the rhabdoms, the dimension of perirhabdomal vacuoles and the number of mult i vesicular bodies was increased, but the pinocytotic vesicles were few and the pigment granules located in the proximal region.