Abstract:Gut hormones immunoactivities were studied in the gut of grey mullet ( Mugil cephalus L. ) using ant isera against mammalian 5..hydroxytryptamine ( 5..HT) , somatostatin ( SST) , gastrin ( GAS) , P substance, vasoactive intestinal peptide ( VIP) , insulin and glucagon. 5..HT, SST, VIP, GAS, P substance immunoactive cells were detected in the gastroenteric muco sa of grey mullet, but the immunoactivity of glucagon and insulin in the gut mucosa was not detected. In the present paper, the morphological characteristics and the distribution density in all stomach intestinal segments of immunoreactive endocrine cells in the gastrointestinal tract were described. At the same time, the possible way of secretion and the physiological function of these endocrine cells were discussed.

Abstract:Total RNAs were extracted from eyestalks of the shrimp Trachypenaeus curvirostris . Eyestalk complementary DNAs were obtained from these total RNAs by reverse transcription. Based on the amino acid sequence of the neuropeptide Pe-j SGP- . which has mol-t inhibit ing activity from Marsupenaeus jap onicus, two degenerate primers were designed. Polymerase Chain Reaction ( PCR) was performed using these primers and these eyestalk cDNAs. A specific cDNA was amplified under proper conditions. The specific cDNA was cloned into vector for sequencing . The sequencing results demonstrated that the specific cDNA from the shrimp T. curvirostris consisted of 213 base pairs. The alignment of the deduced amino acid sequence from eyestalk cDNA of the shrimp T . curvirostris with neuropeptides of CHH family from various crustaceans demonstrated that it had the highest identity and homology with most MIHs from various crustaceans. It suggested that the deduced amino acid sequence from eyestalk cDNA of the shrimp T . curvirostris was a part of MIH neuropeptide of T. curvirostris. The sequence corresponded to the amino acid sequence from 5 to 75 residues of MIH.

Abstract:RAPD analysis amplified by ten 10- mer random primers including Z2 and Opp17 was used to compare the genetic variations among three mitten crab populations from Skokely in Holland ( Europe) , San Jose of California in United States, and the Yangtze River in China. The results showed ( 1) The Z2700bp band, genet ic identification marker in mitten crab Eriocheir sinensis, can be amplified in both Europe and North America populations. However, the Z2880bp band, genetic identif ication marker in mitten crab Eriocheir Japonica , can not be amplified in these two populartions. It indicated that the mitten crab in Europe, USA, and China were the same species of Eriocheir sinensis but not the Eriocheir japonica; ( 2) The frequency of 947bp band amplif ied by primer Opp17 all reached 100% in above three populations. Combining of results from primer Opp17 with results from primer Z2, it indicated that it is most possible that examined mitten crab populations from Europe and USA were immigrated from the popualtion of the Yangtze River of China.

Abstract:Moina mongolica continuously reproduced 24 generations through parthenogenetic reproduction in 105 days during which M. mongolica were individually reared in laboratory under constant temperature ( 25 e ) , salinity ( 10) , and food condit ion ( 3 @ 106cell #ml- 1 Chlorella spp. ) . There was not significant decline in reproduction capacity for the progenies that were parthenogenetically reproduced. 74. 1% individuals in the experiment reproduced four broods. Time for the first brood was 4. 28 ? 0. 37days ( mean ? SD) . Interval between two broods was 2. 30 ? 0. 41 days within 1 to 4 broods while number of offspring per brood was 7. 52 ? 1. 39. This experiment indicated that there was not significantly negat ive effect on reproduction capacity of M. mongolica following 24 generations of continuously parthenogenetic reproduction.

Abstract:The development of germ cells of peanut worms, Sipunculus nudus , proceeding with seasonal alternating was observed by optical microscope to study reproductive cycle of the population in the sea of Guangxi. Samples were co llected monthly from January 1999 to February 2000 at three sites along the coastal sea f rom Daguansha to Baihutou in southern Beihai. Observations in this study have bring to light as follow: All individuals observed were dioecious. The earliest germ cells of both males and females were small in size and appeared in clumps attached to nurse cells of motive activity . The oocytes underwent f ive stages of development: cell multiplication ( 1- 2..m in diameter) , plasmic growth ( 3- 30..m) , follicle format ion( 30- 70..m ) , jelly coat formation( 70- 160..m) and mature egg w ith germinal vescle disappeared ( ..160..m) . The spermatocytes underwent 4 stages: cell multiplication, plasmic growth, cell dif ferentiation and maturity. The germ cells were found in the coelom all the time of a year. The spawning of this population in Guangxi.. s sea area took place several times from April to September each year and peaked from May to August.

Abstract:The sediments immediately under the cage once rearing Oreochromis niloticus showed significantly higher content s of organic matter ( OM) and phosphatase hydrolyzable phosphorus ( PHP) , and alkaline phosophatase act ivity ( APA) as well. In interstitial water, both APA and orthoposphate ( o-P) concentrations were signif icantly higher, while PHP was significantly lower, at vertical and horizontal scales. These results suggested that the enhancement of o-P release from sediment, resulted f rom the enrichment of OM, might be controlled by an enzymatical mechanism. The Langmuir isotherm approach revealed that, in interstitial water under the cage, sorption capacity was signif icantly higher, while the corresponding sorption strength was signif icant ly lower in the upper layers, which lends an additional explanation to the enhancement of o-P release in the sediments as affected by the cage culture. A remarkably seasonal variation in vertical patterns of kinetics of APA was observed in interstitial water.

Abstract:Based on the Newton. s second law and the conservation law of angular momentum, the hydrodynamic equations of the SeaStation cage under the action of both waves and currents were derived, and their numerical solut ion has been obtained. Given the current velocity of 1. 5 m#s- 1, wave length of 50 m, period of 8 s, depth of 30 m, the results showed that the force of waves of heights over 5. 5 m was greater than current force, and that the force varied periodically and asymmetrically. On the contrary side the current force became dominant force. Under the same case, the maximum force decreased from the 21. 1t of sea surface to 10. 4t, when the cage lowered 5 m, so it is possible to decrease the force acted on SeaStat ion by lowering its depth. Some parameters used in the paper need verifying and modifying through further survey .

Abstract:8 species of shellfish which were collected from Jiangsu and Zhejiang Provinces in Feb. 1992 , were detected for okadaic acid by high performance liquid chromatography with 92chloromethylanthracene (92CA) and tetramethylammonium hydroxide ( TMAH) . The result showed that the range of okadaic acid content is from 15. 75～218. 95ng·g -1 , and the average of content is 37. 10ng·g -1. 48 % samples were detected okadaic acid , and the content of one sample was beyond the critical limit (200ng·g 1) . It suggests that the diarrhetic shellfish poison is widely distributed in China , and shellfish from some areas contain high toxicity.

Abstract:1982day feeding trials were conducted to determine the reciprocal physiological effects on Chinese mitten2handed crabs Eriocheir sinensis female broodstock by feeding with four experiment diets and one control group diet for: diet 1 supplementing HUFA and vitamin E, C; diet 2 supplementing only vitamin E and C; diet 3 supplementing neither HUFA nor vitamin E and C; diet 4 supplementing only HUFA , diet 5 (control group diet) was fresh clam. The results showed that vitamin E, vitamin C and HUFA were essential components in broodstock diets. Fecundity and hatchability of eggs from broodstock crabs fed with diet 1 in which HUFA and vitamin E, C were supplemented were 3790 egg cell·g 1 and 86. 17 % respectively , were the very significantly higher than those of broodstock crabs fed with HUFA2deficient diet like diet 2 and 3 (2317egg cell·g-1, 36.06 % and 2129egg cell ·g-1, 29. 18 %) ( P < 0. 01) , and significantly higher than those of and fecundity and hatchability of eggs (3050 egg cell·g 1 and 25. 73 % in diet 4 treatment) from the crabs fed with diet 4 were also lower than those of control group (3010 egg cell·g 1 and 71. 12 % respectively) ( P < 0. 05) . When the broodstock crabs were fed with vitamin E and C2deficient diets like diet 3 and 4 , lipids of crabs were peroxidized with decreasing SOD activity and increasing MDA content. Meanwhile , the effect of total lipid content , fatty acid composition and vitamin E and C concentrations of experimental diets on those of corresponding eggs , and the lipid peroxidation in eggs are discussed. The results of this study indicate both HUFA and vitamin E , C are indispensable and cooperative to egg developing of crab and must be supplemented in the broodstock crab diet.

Abstract:Japanese sea bass ( Lateolabrax japonicus ) were fed by six diets for 8 weeks to study the effects of different diets on the growth, nutrient composition, fatty acids composition and serum biochemistry indexes of f ishes. Five formulated diets all contained about 9. 79% lipid content with different lipid sources: fish oil, mixture of f ish oil and corn oil ( 1. 34..1) , mixture of fish oil and soybean oil ( 1. 34..1) , the rest two formulated diets contained fish oil and more choline ( 100g..kg - 1 ) and carnitine ( 350mg..kg - 1 ) added respect ively. .. Iced trash fish.. ( Saurida tumbil ) were used as control diet . The results showed the tolerance to fat liver of Japanese sea bass was weak and the detrimental effects would be seen if f ishes were fed by a large quantity of .. iced trash f ish.. for long time. Different lipid sources made no significant difference on the growth of Japanese sea bass when its EFA requirements were met, but they could take some effects on the lipid deposit in f ishes. Choline and carnitine had some effects to reduce the lipid of the fish.

Abstract:Allogynogenetic crucian carp( body weight 1. 6- 2. 2g ) were fed with formulated diet which had been added w ith Chinese herb ( additive ., additive ò) at different contents of 0. 5% , 1% and 2% respectively. Growth rate, apparent digestibility of protein and protease activity in intestine and hepatopancreas were determined in two months. The results showed that Chinese herb additives signif icantly increased growth rate, protease activity in intestine and hepatopancreas, and apparent protein digestibility of allogynogenetic crucian carp( P < 0. 01) . The growth rates of the treated groups 1% of additive ., 2% addit ive . and 2% additive ò were 23. 74% , 32. 74% and 47. 06% higher than those of the control respectively. The effect of the additives on protease activity in intestine and hepatopancreas, and apparent digestibility of protein was the same as the growth rate. Protease act ivities of the control and the treated groups 1% of additive ., 2% addit ive . , 2% additive ò in intestine were 10. 54, 20. 33, 22. 79, 25. 68, and those in hepatopancreas were 8. 54, 14. 13, 16. 59, 20. 36 respectively. Apparent protein digestibities of these groups were 78. 15%, 84. 38%, 86. 98% and 88. 19%. Therefore the increase of the protease activites and absorbabilities was an important factor to increase fish gro

Abstract:Leptocephalus larvae are the unique stage of larval development in all groups of fishes from the superorder Elopomorpha ( Anguilliformes, Elopiformes and Notacanthiformes) . To explain the leptocephalus strategy of larval development, various attempts have been made on the morphology, physiology and biochemistry of leptocephalus larvae. However, the feeding mechanism of leptocephalus larvae is st ill unknown. The Japanese eel ( Anguilla japonica ) larvae were found to have well developed scotopic vision, mechanoreception and chemoreception. Both early and leptocephalus larvae of Japanese eel actively ingested a kind of paste food by first touching the food with their snout and then tearing off a big mouthful of the paste with their sharp teeth. Chemoreception was shown to be critical to elicit the feeding response. Feeding by S-f lex posture from a distance might be of some significance for the early larvae to catch movable food. It is proposed that that the natural food of Japanese eel larvae would be relatively large, rather soft, inactive and negatively phototactic. The developmental mode of sensory system and behavior of Japanese eel larvae seems to be similar to some deep sea fishes but contrast w ith most marine teleost fishes.

Abstract:This paper presents the effects of harmful algae on f ish based on the studies in recent years. The results show that the harmful algae can affect the survival, enzyme, cell, tissue and behavior of fish directly or indirectly, also the phycotoxin can be accumulated in the tissue and organ of fish, and inf luence the organisms of higher level. At last, we have discussed the elements that affect the toxicity of harmful algae.