Abstract:Morphological and histological studies on the digestive system of the Amur sturgeon, Acipenser schrenckii showed that it has stomach, pyloric caeca and valvula intestine, and its pancreas has developed into an independent organ and also disperses into the porta hepatis of liver. There are some differences between A. schrenckii and A. sinensis in the number and shape of mucous membrane pleat in oral cavity, and also in the number of the subsection of esophagus, i. e. A . schrenckii has three subsections but A. sinensis has two subsections. A . schrenckii. s valvula intestine has seven spiral valves, less than those of A . sinensis. The pyloric caeca of A. sinensis is composed of seventeen little bursa, and A . schrenckii is between ten and twelve ones.

Abstract:The development of the digest ive system and its associated glands was examined histologically in Epinephelus coioides from the f irst day ( f irst day pos-t hatch) until 60th day after hatching. Specimens for this study were hatched f rom naturally spawned into artificially broodstock and maintained indoor cement tanks( 22. 0 - 27. 8 e ) . During the f irst 4 days after hatching, the formation of the oral jaw apparatus, lengthening of the digestive tube, the resorption of yolk sac, the digestive glands ( liver, gal-l bladder and pancreas) appearance, and muco sae differentiation are the most conspicuous elements of development . The larval digestive system is morphologically ready to process external food at the time of mouth opening ( 4 days after hatching) . The most noticeable events occurring during the following period of independent life are an increase in mucosal folding, cellular differentiation in the luminal epithelia, gut segmentation, liver growth and pancreas development. The digestive tract consists of clearly distinguishable oesophagus, stomach, intest ine and rectum. The major digestive glands include liver, gal-l bladder and pancreas. Then, these digest ive tract and digest ive glands become mature gradually, and complete the morphological digestive features characteristic of the juvenile stage with increasing age and feeding activity. The pancreas is composed of small independent masses in 4 days in larvae, and spread along the upper intestine with the larvae growth, but in the adult, it is difficult to discern. Although the entire larval period, from hatching to metamorphosis ( from larvae and juvenile stage to fry ) , was under consideration, the observations were concentrated on the most dynamic early stages of development occurring after hatching. It is expected that this information will improve our understanding of larval or juvenile digestion physiology and will be useful in design of opt imal rearing techniques and in the development of art ificial food for the larvae.

Abstract:Based on 6 morphological characters of Cristaria plicata, Hyriopsis cunimgii , Anodonta woodiana pacif ica, A . woodiana elloptica and A . globosula in Unionidae, multivariate morphometrics were used to investigate their morphological variations among 5 species and 6 region populations. In the result of principal component analysis, two principal components ( PC) were constructed by factor loadings, in which the first principal component ( PC1) was affected by 4 characters and the PC2 was affected by 1 character, and the contributory ratio of two PC was 54. 17% and 34. 08% respectively. The results of principal component analysis and cluster analysis revealed that the morpho logical character of C . plicata and H . cunimgii was similar and the morphological character was similar between A . woodiana elloptica and A. globosula. ANOVA and t-test indicated that different region populations of C. plicata and H . cunimgii showed some morphological variations respectively. The discriminant functions of f ive unionid species were established, and the discriminant accuracy was 100% for H . cunimgii and A . woodiana pacif ica, 98. 92%, 86. 36% , 96. 88% for C. plicata, A. woodiana elloptica and A. globosula in turn, so the average discriminant accuracy was 97. 83%.

Abstract:Based on the bottom trawl surveys in the waters off southern Shandong Peninsula in spring 1986, 1998 and 2000, the yearly variat ions of nekton, dominant species were analyzed. The mult ivariate gradient analysis was used in the study of community characteristics. The result s indicate that the period of shifts of species was reduced, the species dominance decreased and the diversity increased in the surveyed areas of the Yellow Sea. Therefore, the community structure has greatly changed, and succession increased.

Abstract:Seasonal investigations were carried out for 3 cultured areas ( of algae, oyster and fish ) and noncultured area in Xiangshan Bay. 71 species from study areas were identif ied. 45 species of them were collected in cultured areas, 61 species in non-cultured area, 35 species from both cultured and non-cultured areas. The biomass and density in oyster and f ish cultured areas were 433. 53g ..m- 2 and 155ind..m- 2, 91. 92g..m- 2 and 115ind..m- 2 respect ively. It was higher than that in algae cultured area and non-cultured areas. The biomass and density in algae cultured area were 1. 55g..m- 2 and 27. 5ind..m- 2, which was lower than that in non-cultured area ( 5. 24g..m- 2 and 53. 04 ind..m- 2) . No macro-benthic species was found in the center of f ish cultured area. The relativity of the benthos with sediment, reared biology and hydrographic factors is discussed.

Abstract:Studies on culture of parent crayf ish, winter rearing, hatching and indoor artificial breeding of the red crayfish ( Cherax quadricarinatus ) were carried out from 1996 to 1998 in the northern region of Zhejiang Province. Results showed that the red crayfish is appropriate for farming and breeding in Zhejiang Province. In the northern region of Zhejiang Province, the juvenile crayfish ( sizes of 2. 8- 4. 9g) can grow to sexual maturity and the survival rate in pond was over 70% during the winter seasons because of warm water supply from a local power plant. In February, when the water temperature went up to 20 .. , the parent red crayf ish began to copulate and breed, but the epacme were observed in April to June. The red crayfish can spawn four times a year, but only the first and the second hatches are useful for juvenile nursing purpose. A female brood normally ovulate 400- 500 eggs, but the spawning rate of the population in a pond is commonly high. The red crayfish develops from fertilized egg to juveniles directly, which is quite different from crabs and shrimps. The hatch need stay on the pleopod of the female brood for 7 to 10 days, and then begin to leave and live on extraneous foods. The juveniles do not need live food absolutely. A formulated feed has been developed successfully for nursery stage juvenile. Temperature regulation and intensive management during the indoor nursery stage are very important for juvenile nursing success, and the survival rate can reach up to 60%.

Abstract:Three experiments were conducted to study the effect of adding xanthophyll on body color of Clarias fuscus. In experiment A, walking catfish were collected from natural river, common pond and concrete pond, representing wild, semi..cultured and cultured walking catf ish. The xanthophyll content in skin and muscle of each group was 8. 01, 4. 64, 1. 61 and 2. 06, 1. 83, 0. 96 mg..kg - 1 respectively. In experiment B, adult walking catfish, with an average weight of 52g, were divided into 4 groups and fed w ith artif icial diet without ( control) or with 100, 150, 200mg..kg- 1 xanthophyll for 6 weeks. The xanthophyll content in skin and muscle of each group was 1. 07, 5. 88, 7. 02, 7. 81 and 0. 64, 1. 35, 1. 81, 1. 86 mg ..kg - 1 respectively. In experiment C, f ingerling walking catfish, with an average weight of 3. 2g, were divided into 4 groups and fed with artif icial diet w ithout ( control) or w ith 50, 100, 150mg..kg- 1 xanthophyll for 6 weeks. The xanthophyll content in skin and muscle of each group was 3. 2, 8. 73, 11. 49, 12. 51 and 0. 87, 1. 71, 1. 97, 2. 03 mg..kg - 1 respectively. The results showed that the dif ferences of body color between wild and cultured f ishes come from the different xanthophyll content in diets, the addit ion of xanthophyll could improve body color of walking catfish and the feeding strategy for pigment was adding xanthophyll 100 mg..kg- 1 in diet for adult walking catfish or xanthophyll 50 mg..kg- 1 for fingerling.

Abstract:The development of the fertilized eggs and the development and growth of yolk-sac larvae of Tinca tinca in the period of starvation were observed and the point of no return ( PNR) was also studied. The results show that : ( 1) The embryo was hatched for about 52 h before hatching out with water temperature 21. 5 e . ( 2) After hatching, the larvae started to feed on the seventh day with low initial feeding rate, the initial feeding rate reached the highest figure 100% on the ninth day , and then decreased to 50% on the twelfth day, while the larvae reached the poin-t of-no-return. ( 3) After hatching, the highest yolk-sac consuming rate happened on the f irst day, while the highest growth rate of total length of larvae occurred on the second day. ( 4) On the eighth day after hatching, the yolk sac was absorbed completely, from then the starved larvae decreased in total length.

Abstract:In this paper we study and compare growth pattern of Oratosquilla oratoria and Oratosquilla kempi , evaluate and compare nutrit ive value, and investigate relationship between biochemical composition and growth, reproduction by measuring body length and weight , biochemical composition and content, respectively. Results show that both the body length relation and the body weight relation between two species can be expressed in the signif icant linear correlation, body weight bears power function relation to length, and during the growing period two body shapes are mainly stable. The content s of water, lipid and ash in muscles are not of signif icant difference, except for that of crude protein ( P < 0. 05) . During the test months lipid contents have litt le f luctuation but contents of water, ash and protein are all on the rise. The differences in amino acids( AA) and fatty acid composions in muscles of Oratosquilla oratoria and Oratosquilla kempi were found. The values of AA, EAA and Asp+ Glu Gly of the latter are higher( P < 0. 01) than those of the former, and unsaturated fatty acids of the former are higher than those of the latter.

Abstract:The hepatopancreas index ( HI) , lipid content ( LC) and fatty acid composition in Eriocheir sinensis before and after the precocity, were compared by gravimetry and gas chromatography. The results showed that HI and lipid content both decreased after the precocious molt, regardless of their sex. As for fatty acid composition of hepatopancreas, immature male and female individuals were very similar, except for C20..5n- 3 significantly higher in the latter ( P < 0. 05) . However, it varied with the sex when the precocious and immature crabs were compared. In female, the percentage content of C16..1n- 7, C16..0 and C18..0 were signif icantly higher in precocious individuals, but that of C20..4n- 6, C20..5n- 3( EPA) and C22..6n- 3( DHA) signif icant ly lower( P < 0. 01) . And in male, there was only C18..1 signif icant ly higher ( P < 0. 05) in precocious individuals while C14..0 ( P < 0. 05) , C16..1n- 7( P < 0. 05) and C20..5n- 3( P< 0. 01) lower. According to the results, it might come to the conclusions that EPA is very important during precocious molt and construction of membranes, while DHA mainly participates in the development of ovary and vitellogenesis.

Abstract:Cultured trials lasting 198 days were conducted to determine the physiological effects of dietary vitamin C and E on reproductive performance of the Chinese mitten-handed crabs Eriocheir sinensis, with mean weight of 78. 21 ± 25. 68g, and female broodstocks were fed with four experimental diets of varying composition. The control group was fed with fresh clams. The gonadosomatic index ( GSI) , fecundity, hatchability of eggs, activities of SOD and the content of MDA in the different tissues, were used to evaluate the performance of the crabs fed w ith different diets. The results showed that the fecundity and hatchability of groups 1, 2 and 3 were 3 620 cell#g- 1( body weight) and 83. 03% ; 3 540 cell#g- 1 ( body weight ) and 84. 06% and 3 790 cell#g- 1 ( body weight) and 86. 27% respectively, which were very signif icantly higher than those of group 4 ( 2 490 cell# g - 1 body weight and 29. 28%) ( P < 0. 01) , and tho se of group 5 ( 3 010 cell#g - 1 body weight and 71. 12%) ( P < 0. 05) . The SOD activities in ovaries of groups 1, 2 and 3 were 56. 35Nu#mL- 1, 53. 61Nu#mL- 1 and 39. 87Nu#mL- 1 respectively, significantly lower than those of group 4 and 5 ( P < 0. 05) , and MDA contents were 6. 03nmol#mL - 1 , 5. 65nmol#mL - 1 and 5. 57nmol#mL - 1 respectively. Though the SOD activity in ovaries of group 4 was 79. 25Nu#mL- 1, peroxidation still took place because of def iciency in VC and VE, so MDA content in ovaries of group 4 was high, 23. 18nmol#mL- 1, resulting in very low hatchability of group 4. This experiment demonstrated that VC, VE supplemented in the diet s of female broodstocks can improve the reproductive performance.

Abstract:The pathogens from ill turtles, eels and Ictiobus cytrinellus were separated, purified and identif ied to prove up the biocontrol function of Photosynthetic bacteria ( PSB ) on diseases of aquatic animals. The pathogenicity of pathogens is examined by artificially infecting the healthy animals. And the antibacterial abilities of sal-t resistant Rhodospirillaceae bacteria against those separated pathogens were studied. At the same time, the phases that PSB produces ef fective antibacterial action were determined. The results show that the separated pathogens from aquatic animals are Vibrio , Aeromonas, and Pseudomonas. The metabolic products of sal-t resistant Rhodospirillaceae bacteria show the bacteriostastic activity to those separated pathogens: the diameter of ant ibacterial zone is 1. 2- 1. 4cm, the minimal inhibitory concentrat ions ( MIC) are mostly at the diluted times 4 - 8. The antagonistic substances of sal-t resistant Rhodospirillaceae bacteria are produced in the exponential phase initially and reached maximal concentration in the contabescence phase.

Abstract:The pathology and tissue concentrat ion of the chronic olaquindox poisoning in common carp, Cyprinus carpio , were studied. The test was conducted for 90 days, with doses of 10, 25, 50, 100, 150 and 200mg#kg- 1 feed. The morbidity and mortality were 17. 5% , 27. 5%, 35. 0% , 42. 5%, 47. 5% , 55. 0% and 5. 0% , 10. 0%, 12. 5% , 17. 5% , 20. 0%, 30. 0% respectively. The clinic symptom of the poisoned fish was characterized by / the stress hemorrhage syndrome0. The lesions of poisoned cases showed hyperplasia, degeneration , necrosis and desquamation in the gill lamella epithelia, fatty or vacuolar degeneration and necrosis in the liver cells, the catarrhal enteritis, vacuolar degeneration in renal tubular epithelial cells, cardiac muscle cells and the adrenal gland cells. Ultrastructurally, the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells were swollen with disintegration and lysis of caritas. The fat drops increased in liver cells. The intestinal epithelium microvillis collapsed and desquamated at the first stage of the test , and then many intestinal epitheliums necrosed and desquamated. Hematologically , the Hb concentration and the RBC numbers dropped; the serum AST and ALT activity were raised. The olaquindox concentration in the liver, kidney and muscle of the test groups was signif icantly different from the control group.

Abstract:This paper analyses some practices of maritime delimitation of coastal countries and judicial practices of the International Court or Arbitration Court after the brief introduction of the general geography and resources conditions of East China Sea. On the basis of above analysis, the author sums up some main factors considered by relevant states when they delimitate the maritime boundaries, such as geography, geology, the unity resources, economy, historical rights ( traditional fishing right) . The author analyses these factors combined with Chinese, actual conditions, then expounds the possible delimitation: delimitating the Exclusive Economic Zone (EEZ) and the Continental Shelf on respective length proportionality of coastal lines. At last, some viewpo ints are expounded about the marine boundary between China and Japan.

Abstract:Fish thymus is phylogenetically the first well..developed lympho..epithelial structure for most fish species. It supplies microenvironment for T..cell differentiation and is directly involved in defense mechanism. The current status of the f ish thymus research was reviewed in the fo llowing aspect s: 1) structure and possible funct ions; 2) origin, histogenesis and degeneration; 3) ontogeny and function of T..lymphocyte obtained with monoclonal antibody.