| Cromileptes altivelis is a senior marine economic fish, it has high nutrition and highprices. In recent years, the increased demand for Cromileptes altivelis, its high price tobring good economic benefits for the farmers. Therefore, Cromileptes altivelislarge-scale breeding has been developing rapidly in the South Sea of China. To learnmore about the studies on digestion mechanismin and the morphological structure ofimmune organs in Cromileptes altivelis, the main contents of this paper: effects oftemperature and pH on the activities of digestive enzymes and on the morphology andhistology of immune organs in Cromileptes altivelis, histological studies on digestivesystem of young Cromileptes altivelis. The main results were showed as follows:1Effects of temperature and pH on the activities of digestive enzymes in CromileptesaltivelisThe effect of reaction temperature and pH on the activities of3main digestiveenzymes (protease, lipase, amylase) of Cromileptes altivelis were studied usingenzymology analysis method. The results show that: the activities of all digestiveenzymes in Cromileptes altivelis increased at first and then decreased with temperatureand pH increasing in the designed temperature and pH ranges. In stomach, the optimaltemperature for protease was40～45℃, whereas all in intestine, pyloric caecum andliver were40℃. The optimum temperature for lipase in stomach was35℃, theoptimum temperature for the pyloric caecum was40～45℃, the others were all40℃respectively. The optimum temperature for amylase in stomach was40℃, The otherswere all35℃respectively. The optimum pH for protease in stomach was3.2, theoptimum pH in intestine, pyloric caecum and liver were all8.2.The optimum pH forlipase in stomach and liver were7.2,8.2, the others were all6.2respectively. Theoptimum temperature for amylase in stomach was pH7.2～8.2and others were all7.2.Under optimum temperature and pH, the activity of lipase in different organs wasin the order of anterior intestine> stomach> liver> pyloric caecum, and the activities ofamylase were intestinal> the pyloric caecum> stomach> liver.Under optimumtemperature and pH,the order of protease were intestine> stomach> liver> pyloriccaecum and intestine> stomach> pyloric caecum> liver.2Histological studies on digestive system of young Cromileptes altivelisWe studies the histological structure in the digestive system of young Cromileptesaltivelis by using HE in this paper. The results showed that: Mucous cells and taste budswere founded both in the lips and tongue, goblet cells were not founded in lips, but abundant in tongue; The mucosa layer of esophagus, esophagus was short and think,was covered with wrinkles and folds with numerous mucous cells and goblet cells,taste buds were not founded, muscle layer of esophagus were well developed which wasstriated muscle; The stomach consisted of cardiac portion，blind sac and pylorus portion.The account of mucosa layer’s folds: cardiac portion> blind sac> pylorus portion, theaverage height of mucosa layer’s folds: blind sac> cardiac portion> pylorus portion.Concave-shaped structure was observed in stomach without goblet cells be founded,The gastric gland were well developed; The intestine was divided into fore intestine、mid intestine and posterior intestine. The number and average height of mucosa layer’sfolds in intestine: foregut> midgut> hindgut, The striated border was obvious inintestine with numerous goblet cells and mucous cells; The results of observation inpcyloric caeca were similar with the results in intestine. Lobuli hepatis were obvious.The distribution of central vein was irregular. Hepatic sinusoid was abundant. Thehepatic cell cords were obvious, Hepatic artery and bile duct could be observed. Thepancreas was disperse around the liver. Langerhans’ islet was oval cluster, the pancreaticacinus were abundant, the pancreatic cells could be observed obviously.3On the morphology and histology of immune organs in Cromileptes altivelisThe microstructure of the head-kidney and spleen of Cromileptes altivelis wasobserved using light microscope. The results showed that the surface of the head-kidneywas covered with a very thin layer of fibroid connective tissue capsule but with noobvious trabcula and nephron.There were red blood cell centers and leukocyte centersin head-kidney, it was mainly composed of lymphoid tissue, blood vessels and sinuses,melano macrophage centres were found. The surface of the spleen was also coveredwith a very thin layer of fibroid connective tissue capsule but with no obvious trabcula,mainly composed of red pulp and white pulp. The spleen was chiefly composed of largequantities of lymphocytes，granulocytes, ellipsoids, blood cells and melano macrophagecenters. Many arteries，veins and nerve bundles in parallel arrangement were found inspleen．... |
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