Abstract:The objective of this study was to investigate the effects of 17α-methyltestosterone （17α-MT） on gonadal development, serum steroids and aromatase activities in 2-year-old female red-spotted grouper（ Epinephelus akaara ） during reproductive season. Groupers were divided into two groups, one implanted with 17α-MT （ 10 mg? kg^-1 body weight） and the other elastomer without 17α- MT into peritoneal cavity once every four weeks for 8 weeks. Blood samples were obtained from 6 fish of each group every 4 weeks for later analysis of sex steroids. After blood samples were collected, forebraln, midbrain, hindbrain, and gonads were collected and stored at - 70 ℃ for later aromatase activity measurement and gonadal histological study. Significantly lower gonadosomatic index （GSI） was observed in 17α-MT-treated group. Fish implanted with 17α-MT once showed complete degradation of oocytes and sex inversion with developing testicular tissues at the 4th week, while all fish in the control group were still female with developing ovaries. 17α-MT induced females to develop into functional males with authentic testes similar in structure to those in normal males, and no significant difference in sperm motility rate and concentration was observed between them. 17α-MT elevated the aromatase activities both in forebraln and midbrain but reduced that in hindbrain, with no difference in gonad before and after 17α-MT implantation. Serum 11-ketotestosterone （11-KT） levels increased significantly on the 4th week, while no differences of serum testosterone （T） and estradiol-17β （E2） levels were observed in control and 17α-MT-treated group. Present results suggested that the elevation of brain aromatase activities was associated closely with sex reversion, and the increasing 11-KT levels may be important for sex inversion induced by 17α-MT in red-spotted grouper.

Abstract:The most abundant neuropeptide, crustacean hyperglycemic hormone （CHH） has been first extracted from sinus glands of Eriocheir sinensis, and purified to homogeneity by reverse-phase high performance liquid chromatogram （RP-HPLC）. The sinus glands of Eriocheir sinensis are the organs to store neuropeptides, which are quite perfect to do research for the neurosecretory system of Eriocheir sinensis. For the crab Eriocheir sinensis, CHH accounts for （ 153.63 ? 32.23） ng（n = 4） per SG, while the extracts of one sinus gland reach （ 1252.63 ? 298.40） ng（ n = 4）. In crustaceans, the CHH and the structurally related peptides MIH （ moltinhibiting hormone）, VIH （ viteUogenesis inhibiting hormone） and MOIH （ mandibular organ inhibiting hormone）, are classically considered as the major physiological regulators involved in the control of carbohydrate metabolism and in different functions such as molt, reproduction and hydromineral metabolism. The amino acid sequences of these neuropeptides hormones are similar to each other： they consist of 72 - 78 residues with six conserved cysteine residues arranged in three disulfide bridges. CHH shows obviously hyperglycemic activity, which can make the haemolymph of the crab Eriocheir sinensis reach the highest level （56.14 ? 10.58） mg?100 mL^- 1 ） only in 30 minutes, while the CHHs from any other species that have been examined show hyperglycemic activity in about 2 hours. The molecular weight of CHH was examined by SDS-PAGE under the indication of protein Marker （BBI, from 4.1 kD to 66 kD）, the result was 5.1 kD with the use of GDS Microsoft to analyze, which is much lower than any other CHH （7 - 9 kD） that has already been known. In recent years, the amino acid sequences of the CHHs from many species of orustaceans have been determined, however, no sequence data for CHH from Eriocheir sinensis has been reported so far, and will be reported later. In this paper CHH from Eriocheir sinensis has been separated and its biological activity has been examined, the results of the experiment will be helpful for the further research in the synthesis and secretion of the neuropeptides, as well as have laid the foundation to determine the physiological function of other neuropeptides hormones in the sinus glands.

Abstract:Horizontal starch gel electrophoresis was used to detect the genetic variation of PGM and GPI in five marine organisms, sea urchin（ Strongylocentrotus intermedius ）, sea cucumber（ Apostichopus japonicus Selenka）, sole （ Cynoglossus semilaevis ）, hard clam （ Meretrix meretrix ） and scallop（ Pecten yessoensis ）. For sea urchin, the PGM showed high expression activity in muscle and mature gonad and the loci number was different in the two tissues, while the activity of GPI was rather low. The isozyme demonstrated the same number of loci in the muscle and intestines of sea cucumber, but their activity was quite different. Two PGM loci and three GPI loci were detected in sole＇ s muscle. For the hard clam adductor, the PGM showed high polymorphism and GPI showed monomorphism. One PGM locus and one GPI locus were detected in adductor muscle of the scallop, indicating the low variation of two enzymes. The genetic parameters and genetic variation of PGM and GPI were analyzed for these marine cultured species in Northern China. The genetic structure and relationship between genetic parameters and economic waits were discussed, which will be important in selective breeding programs.

Abstract:The morphological features of spermafids at different stages, and the structural dynamic changes of organelle during spermatogenesis of Octopus tankahkeei were investigated by transmission electron microscope. Spermatogonium is elliptic in shape with large nucleus. Less mitochondria and Golgi bodies in cytoplasm of spermatogonium. The primary spermatocyte is round or oval in shape, with more mitochondria in cytoplasm. The endoplasmic reticulum is more developed and is rope-like in shape, and the Golgi bodies accumulated and the centriole is also seen in the cytoplasm in the primary spermatocyte. The secondary spematocyte is round, elliptic or irregular in morphology. The cristae in mitochondria in the secondary spermatocyte are well developed, and the matrix of mitochondria is rich; also the electron density materials were accumulated in Golgi vacuoles and the ＂9 ＋ 2＂ arrangements of axoneme are extended from centriole at this stage. The spermiogenesis can be divided into 6 continuous steps based on the morphological changes of acrosome, nucleus and mitochondria. Three main events happen during spermiogenesis. （ 1 ） The chromatin in spermafid undergoes a process of granulation, fibrosis, and stratification, and finally is highly condensed with high electron density. At the same time, the morphology of nucleus changes gradually from ellipse, and long ellipse to slim column. Endonuclear channel was formed by the concave of the posterior nucleus. The coagulation of chromatin and the pressure posed by peri-nuclear microtubules help the formation of the morphology of the nucleus. （2） Golgi vacuoles accumulate density materials, fuse into acrosoml vesicle, and finally, the pre-acrosome becomes an aiguiUe-like acrosome. The striations and spikes can be seen on acrosome. Endoplasmic reticulum also participates in acrosome biogenesis. （3） Mitochondria move posteriorly to the nucleus and form the chondriosomal mantle of the tail. The formation of the chondriosomal mantle is the biological adaption to internal fertilization of this species. Because of the long chondriosomal mantle, the sperm of Octopus tankahkeei supply more energy than the sperm of bivalves and Archaeogastropoda, the later undergo exterior fertilization. The features of six stages during spermiogenesis are summarized as follows： From stage Ⅰ to stage Ⅱ, the chromatin transforms from conglomeration to granulation, the later which distribute evenly in the nucleus, and also, the peri-nuclear microtubules appear, the posterior nuclear pocket invaginates deeply, the nucleus elongates, and the acrosomal vesicle heaves up; at the third stage, the chromatin is flocculent in shape. Endonuclear channels are formed; at the fourth stage, the chromatin is long fibroid in shape, acrosomal cone is formed; at the fifth stage, the chromatin become stratification, acrosomal vesicle is long cystiform in shape; at the sixth stage, the nucleus is long columned in shape, with condensed chromatin inside, acrosomal vesicle has developed to long cone acrosome and the chondriosomal mantle is formed at mid-piece of tail.

Abstract:Comparing solutions of different pH （5.5 - 9.5） and different salinity to develop suitable basic solution for spermatozoa cryopreservation of pearl oyster Pinctada martensii, we chose the basic solution, which could inhibit the activation and had less influence on the physiological characteristics （such as activity, life span and fertilizing capability） of the spermatozoa, and adopted dimethyl sulfoxide （DMSO） as antifreeze to compound diluents for protecting the spermatozoa. After combination of natural seawater with DMSO （10%） and seminal fluid at the ratios of 1 ： 10 and 1：20, the specimens were transferred into LN2 by 4 temperaturelowering processes. The conclusion showed that cryopreservation processes were effective in which the samples were pre-frozen in 0- 8 ℃ within 30 minutes, swung at 15 cm above for 5 min and then at 5 cm above LN2 for 10min, transferred them into LN2 for prolonging period （24 h, 48 h and 5 months ）, and then thawed them with water at 35-40 ℃, the survival rate of spermatozoa could exceed 60% when activated with 0.25‰ ammonia seawater and the fertilization rate could reach 80%.

Abstract:Heterosis and genetic correlations were analyzed for body weight and 10 morphometric traits flora three variants of red carp, Cyprinus carpio vat. singuonensis , Cyprinus carpio vat. wuyuanensis and Cyprinus carpio vat. color, based on diallel cross data at their adult stage. The results indicated that obvious heterosis was observed in C. carpio vat. singuonensis ? C. carpio vat. wuyuanensis, but no obvious heterosis was found in C. corpio vat. singuonensis ? C. carpio var. color and C. corpio var. wuyuanensis ? C. corpio var. color ; Significant additive correlations existed in body weight and total length, body weight and standard length （ rA 〉 0.9）, but dominance correlations were not significant between them. Significant additive and dominance correlations were found between total length and standard length, total length and caudal peduncle length, standard length and caudal peduncle length （ rA 〉 0.9; rD 〉 0.9）. Meanwhile, significant negative additive correlations existed between total length, standard length and body depth, caudal peduncle depth （ rA 〈 -0.9）. Furthermore, significant negative additive correlation （ rA = -0.896） between body weight and caudal peduncle length, and significant positive dominance correlation （ rD = 0. 970） were also found between body weight and caudal peduncle depth.

Abstract:Metaphase chromosome specimens of Acipenser gueldenstaedti Brandt injected with PHA and colchicin, were prepared from short-term culture of kidney cells with air-drying technique. It diploid chromosome number is 2n = 236?2. The kinetic bodies of the 120 chromosomes were watched and the others are microchromosome. Karyotype consists of 80m ＋ 16sin ＋ 24st, t ＋ 116mc,NF = 332. Diploid nucleus DNA content was measured from the somatic cell of Acipenser gueldenstaedti Brandt, using flow cytometer （ Partec pasⅢ ,made in Germany） and the DNA content （2.3 pg?N^-1） of erythrocytes of chick （ Gallus sp） as standard. It DNA content is 12.24 pg?N^-1, which corresponds with the result measured chromosome number as ploidy. Synthesizing above results, the conclusion was obtained that Acipenser gueldenstaedti Brandt is octalpoid. Compared with the reports about sturgeons and paddlefishes, the results of this paper were identical with the one measured by Song Shu-xiang et al. about A. schrenckii（DNA content is 11.73 pg ? N^-1 ; chromosome number is 238 ?） using flow cytometer, but is different from the ones of P. spathuta （3.96 pg）, P. gladius （4. 11 pg）, A. dabryanus （8. 26 pg）, A. schrenckii （6. 07 pg）, A. sinensis （9. 07 pg） by Zhang siming using microspectrophotometer. These differences are relevant to the methods used （ flow cytometer or microspectrophotometer）, standard DNA（erythrocytes of chick or human lymphocyte）and the DNA absolute content （for example, the DNA absolute content of erythrocytes of chick is 2.3 pg or 3.22 pg）.

Abstract:Microsatellite enrichment by magnetic beads is a fast and efficient method for isolating this molecular genetic marker. Some microsatellite markers of Silurus meriaionalis were obtained by using the method. First, the genomic DNA was cut by the enzyme of Sau3AI, and targeted segments were collected with the size of 400 - 900 base pairs by centrifugation of sucrose density gradient. Then the segments were purified in a low melting agarose gel and ligated with a short linkers （20 bp）, from which, the ＂genomic PeR library＂ was created. These genomic DNA fragments were hybridized with a biotin-labeled SRS （simple repeat sequence） probe （CA）15. The hybrid mixture was incubated with magnetic beads coated with streptavidin. After washing to remove the non-SRS fragments, the eluted single-stranded DNA contained the selected microsatellite DNA. The selected DNAs were then amplified using primers designed complementary to the linkers, cloned into the pMD18-T vector and wansformed into competent E. coli DH5α. In this experiment, we performed the second screening with a radio labeled （CA）15 probe and obtained 178 positive clones. From these clones, 173 microsatellite sequences （about 97.19% ） were isolated, among which 90.60% microsatellites repeated more than 10 times and 75.98% microsatellites were perfect repeats. This allowed us to design 120 pairs of primers with the software Primer Premier 5.0. In addition, 40 pairs of primers were composed and screened. 38 pairs were used successfully to amplify special fragments,among which 31 pairs were polymorphism within species. These show microsatellite enrichment by magneticbeads is a suitable method to acquire microsatellite and it should become a main way to develop this molecular maker. At the same time, the microsatellite obtained can offer useful genetic markers for studying Silurus meriaionalis in the future.

Abstract:Sea cucumber （Apostichopus japonicus ） is regarded as a tonic food and traditional medicine in China. In order to aid in investigation of the population structure and marker assisted breeding, 11 microsatellite markers were developed and evaluated with sixty individuals caught from the offing in Shandong Province, China. In the NCBI database, 20 sequences of Apostichopus japonicus were found to contain microsatellites when data mining was performed. Eight microsatellite-containing sequences were chosen for designing the PCR primers. The results showed that six primer pairs successfully amplified scorable PCR products and revealed polymorphism with 5.2 alleles per locus. The locus AJMS007 had the greatest number of alleles （9）, while the locus AJMS004 had the lowest number of alleles （3）. The average Ho and He values of six loci were 0.3611 and 0.6402, respectively. PIC value was 0.4862 for locus AJMS004, and more than 0.5 for the other five loci. Five microsatellite markers developed and characterized in Parastichopus californicu were used to assess for transferability analysis in Apostichopus joponicus. The results showed that all the five primer pairs could amplify clear and scorable PCR products with expected size in Apostichopus japonicus. A total of 22 alleles were obtained for the five loci, with 4.4 alleles per locus. The locus Psc 2 had the greatest number of alleles （9） and the locus Psc 3 had the lowest number of alleles （2）. The average Ho and He values of the five transferred loci were 0. 1733 and 0.4201, respectively. And Psc 2 showed the highest PIC value of 0.8500.

Abstract:The major histocompafibility complex （ MHC ） was used to study the genetic variation and differentiation in five populations （Yellow River population, Huai River population, Dongting Lake population, Poyang Lake population and Taihu Lake population） of Trionyx sinensis. The major results indicated that the polymorphism of the gene encoding MHC class Ⅰ molecule α2 domain in five populations of T. sinensis was rich. They were： （1） Some nucleotide sequences showed deletions or insertions. Seven different length sequences were obtained, of which 222 bp and 231 bp sequences were the major ones, existing in 42, 23 individuals respectively. （2） 41 different nucleotide sequences were got from 102 clones. The range of similarities of nucleotides was 0.386- 0.995, indicating relatively high difference. （3） Totally, there were 250 usable loci, of which 174 ones were polymorphic sites, accounting for 69.6 %. But there were some differences among populations as follows： ① The percentage of polymorphic loci was： Poyang Lake population（71.2 % ） 〉 Taihu Lake population（58.05 % ） 〉 Huai River population （57.69 % ） 〉 Yellow River population （55.32%） 〉 Dongting Lake population（48.09% ）. ② The range of nucleotide diversity index （π） was： Poyang Lake population （0.4273） 〉 Taihu Lake population（0.2872） 〉 Dongfing Lake population（0.2840） 〉 Yellow River population（0.2727） 〉 Huai River population（0.2463）. （4） The results of analysis of molecular variance （AMOVA） showed that there was significantly genetic differentiation between Taihu Lake population and Yellow River population, Huai River population, respectively, also between Huai River population and Dongting Lake population （ P 〈 0. 001 ）. （5） Yellow River and Huai River population, Dongting Lake and Taihu lake population clustered first respectively, then they clustered with Poyang Lake population by UPGMA and NJ method according to their nucleotide sequences average genetic distances, indicating an obvious divergence between Poyang Lake population and the other four populations on MHC.

Abstract:To clone.the differential expressional genes between the pre-metamorphosis （17 day post hatching, DPH） and prometamorphosis stage （23 DPH）, we used suppression subtracfive hybridization （SSH） to construct a cDNA library of prometamorphosis flounder Paralichthys olivaceus, when the RNA from pre-metamorphosis larvae was used as the driver. The lengths of inserted cDNA fragments in the library ranged from 215 to 774 bp, and the average length was about 558bp, which is much close to the cut frequency of restrict endonuclease Rsa Ⅰ. The percentage of positive clones in the SSH library was 81.8%. Total 45 clones Were sequenced randomly. Using relative quantafive RT-PCR to check the gene expressional level, we thought that the positive clones should express＇at higher level in pro-metamorphosis flounder than that in pre-metamorphosis larvae, otherwise, they should be regarded as false positive clones. Total22 genes represent positive clones including 13 homologue genes with unknown proteins, of which most have high similar sequences with other organisms, and 9 homologue genes with known proteins like prolactin receptorlike, COL1A1,M3-muscarinic receptor, Sfrs3, tropomyosin, ribosomal protein L27, ribosomal protein S12, GAPDH, COL1A3. Among all the 22 positive genes, the frequency of COL1A1 clone was highest as 22.2%, the prolactin receptor-like was next to the highest as 8.9%, most genes distributed with lowest frequency 2.2% in SSH cDNA library. The results of RT-PCR showed that the 11 representative genes all expressed in the heads of pre-metamorphosis and pro-metamorphosis flounder larvae.

Abstract:Based on the catch data of yellowfin tuna captured by Chinese tuna longline fleet in the west-central Indian Ocean from January to June in 2003 and 2004, the basic biological characteristics of catch composition of yellowfin tuna captured were investigated. The result indicated that the processed body weight of yellowfin tuna captured varied between 7 - 81 kg （2003） and 20- 78 kg（2004） respectively, and the dominant processed body weight varied between 20- 50 kg （2003） and 30 - 60 kg （2004） respectively. The fork length of yellowfin tuna captured varied between 70 - 180 cm and 110 - 170 cm in 2003 and 2004 respectively. Mean sex ratio remained some 0.71 and 1.00 in all months in 2003 and 2004 respectively. Monthly sex ratio had an insignificant difference among all months in 2003, however, the ratio varied remarkably during 2004. To frequency of monthly feed fullness, grade 1 and 2 dominant in every month of 2003 and insignificant difference existed among all months. Grade 1 dominant in every month of 2004, and large differences existed in 2004. The sex ratio fluctuates remarkably at a LJFL of less than 100 cm. The variation on sex ratio is insignificant and maintaining to some 0.5 when LJFL falls into 100 - 150 cm. All samples are males at LJFLs larger than 160 cm. The processed body weight and fork length of yellowfin tuna captured had the relationship curves W = 2 ? 10^- 5 L2.9269 between them.

Abstract:Based on the data of 1986- 1990 and 1997- 2001 shrimp resource surveys and monitoring in recent years in the East China Sea, a biological characteristics study of Solenocera koelbeli fishery was given. 6122 Solenocera koelbeli were measured, in which 3077 were female, 3045 male. Survey was condncted at altogether 115 stations in May, Aug., Nov. 1998 and Feb. 1999 in the area between 26?00′N and 33?00′N and west of 127?00′E. The survey vessel was a shrimp-trawl ship, with its tonnage being 100 and power 183.87 kW. The fishing tool was beam shrimp trawl net. The beam length was 20 m and trawl speed was 2 knots; i.e. from one station to adjacent one it only needed one hour. Results showed that the average fishing rate of the shrimp was 562. 3 g? h^-1. The rate hit 1283.8 g? h^- 1 in autumn. The shrimp belongs to the high-thermal and high-saline species and mainly dominated in the water areas in east of 60 isobath and of over 34 salinity and 12 - 24 ℃. On the basis of annual statistics, its community average length and weight of female were 76.0 mm,7.0 g, respectively; of male, 72.8 mm,5.5 g,respectively. Both reached their maximum in June - September and went down to their minimum in Feb- April. The breeding period was in June- Nov., with flourishing period being Aug- Sep.. There were two fast [growth periods every year. The first one was in Aug - Nov, with the relative growth rates being 12.9% - 11.2% for female,7.9% - 5.9% for male. The other one was in April- June next year, the corresponding rates were 22.4% - 13.4% ,14.8% - 14.1%. Female was a little hit more than male, with its ratio being 1：0.99. It took food all the year round and the food taking grade was 1 - 2. The food taking reached its top in summer.

Abstract:Dissolved oxygen （DO） is an important water quality parameter in fishery water. Dissolved oxygen condition has great influence on water quality and growth of cultured organisms. With rapid development of pond cultivation, the dissolved oxygen concentration in pond is gradually attached importance to as factor of water environment. At present we mainly adopt timing and fixed point measurement for dissolved oxygen in pond, so the accurate predication of DO in fishpond has been the key to aquatic breeding. The factor which influences dissolved oxygen in pond is complicated. For a certain pond, the dissolved oxygen is relative to different seasons, measuring time, the position, the depth of tneasturing point, wind speed, the depth and surface area of the pond. The prediction for dissolved oxygen in pond is a problem of multi-variable, non-liuearity and 10ng-time lag. Due to complexity and nonlinearity of influence factor of dissolved oxygen, it is difficult to use precise mathematics model to describe dissolved oxygen quantitatively. The artificial neural network is a nonlinear, optimization tool. By its good characteristics of high nonlinear mapping, self-organization, the ability of high parallel processing, the artificial neural network connects various affected factors. After synthetically analyzing and considering the measurability of all variables, we selected water temperature, nitrite, ammonia value （NO2-N）, and total nitrogen value in the pond as input .variable of the neural network, and dissolved oxygen in pond as output variables of the neural network. This paper applied fuzzy neural networks to predict dissolved oxygen in pond. Fuzzy neural network not only possesses the advantages of the fury system and artificial neural network, but also offsets disadvantages caused by their individual modeling. It collects learning, associating, self-adaptive and fuzzy information processing as a whole. On the basis of this, the project selected fuzzy neural network technology as modeling method of predictiori for dissolved oxygen in the pond. Fuzzy neural networks have nice approximation ability. However, the training of NNs by conventional back-propagation method, i.e. the BPNNs, has intrinsic vulnerable weakness in slow convergence and local minima. Thus it becomes one of the research directions in fuzzy neural network to adopt global searching algorithms to optimize the parameters of fuzzy neural network. A great deal of bibliography adopt genetic algorithm to optimize fuzzy neural network. In this research we adopted the easier global optimization algorithm （particle swarm optimization algorithm） to optimize fuzzy neural network. Particle swarm optimization （PSO） is an evolutionary conaputation technique developed by Kennedy and Eberhart in 1995 and successfully used for nonlinear function optimization and neural network training. It is easy to be achieved and need not adjust lots of pararneters and has characteristics of rapid convergence. In this work, PSO algorithm was applied to training of fuzzy neural network and then compared with BP algorithm, showing faster convergence rate. The experimental results show that the proposed method is effective and more accurate than BP-NNs and the real-world application is potential. The method proposed lays foundation for developing intelligent measuring instrument and applying industrialized mariculture.

Abstract:In order to study immunoregulation role of dietarypolysaccharide and probiotics, the fish Fugu obscurus weighing （ 167.8 ? 24.4） g were randomly divided into 6 groups. The immunosuppression control group（positive control） was given an intraperitoneal dose of 8 mg? kg^- 1 body weight cyclophosphamide（Cy） every 5 days for three times and fed on the basal diet , and the normal control group（ negative control） was injected with 0.9% NaCl solution and fed on the basal diet according to the same procedure. The other 4 groups Were intraperitoneaUy injected of 8 mg?kg^-1 .body weight Cy every 5 days for three times and fed on basal diets supplemented 0.2% chitosan, 0.1% probiotics, mixture of mannan ohgosaccharide, hadde and probiotics, mixture of chitosan and probiotics for 30 d respectively. The number of white cells in peripfieral blood, phagocytic percentage of the peripheral blood leucocytes, activity of lysozyme in hepatopanereas, proliferation responses of T and B lymphocytes from spleen and head kidney stimulated by PHA and LPS, IgM and IFN-α content from super-natants generated from spleen and bead kidney cultivated in vitro were determined. The dose of 8 mg?kg^-1 body weight Cy depressed the non-specific immunity of the fish, and all the above four immunoenhaneers had potential immunomodulationg role on the immunodepressed, fish. During the period of test, every immunity parameter examined could return to the level between depressed level and normal level or to the normal level, even exceeding the normal level. It seemed likely that different immunoenhancers may have different ways in stimulating immune organs, immune cells or immune molecules, and same immunoenhancer may also have different effects upon different immune organs, different immune cells and immune molecules. Nevertheless, according to the overall effect, the.mixture of mannan ollgosaccharide had the least immunomodulatory effect among the four immunoenhancers.

Abstract:Argopecten irradians were stimulated by injection with β-1,3-glucan and its carboxylmethyl-glucan （CMG） with different degrees of substitution （DS） （ including CMG 1, CMG 2, CMG 3 and CMG 4 with DS of 0. 335, 0. 556, 0. 732 and 0. 857, respectively）. The immunological stimulation aclivity of β- 1,3-glucan and CMG was compared by determining the contents of the serum protein and phenoloxidase （PO）, superoxide dismutase （SOD）, lysozyme （LSZ） activity in the serum and blood corpuscle of Argopecten irradian after injection for 24, 48 and 72 h, respectively. The results showed as follows： 1 ） Compared with the control, the serum protein contents had no significant differences in Argopecten irradians injected with β-1,3-glucan. After injection for 48 h, the serum protein contents in group CMG 2, CMG 3 and CMG 4 were significantly higher than those in the control. 2）β-1,3-glucan and CMG 4 could quickly enhance the PO activity in the serum. The bigger DS of CMG , the higher immunological stimulation activity on the PO activity in the blood corpuscle. 3） CMG 4 group was more effective on adding the SOD activity in the serum and blood corpuscle of Argopecten irradiand 4） After injection with CMG 4 for 24 h and 48 h, the LSZ activity in the serum was very significantly higher and higher than that in the control respectively, but there were no significant differences in each treatment at 72 h after injection. As far as the LSZ activity in the blood corpuscle, CMG 3 group was very significantly higher than that in the control at 24 h after injection, and CMG 4 group was significantly higher at 24, 48, 72 h after injection. The results indicated that carboxylmethyl modification could not only enhance the water-solubility of β- 1,3-glucan, but also affect the immunological function. CMG 4 with DS of 0.857 had the most obvious effect on the immunological function in Argopecten irradians.

Abstract:The fatty acid composition and their changes at main developmental stages （ prophase-larvae, anaphase-larvae, juvenile and young） of the Pseudosciaena crocea were analyzed by means of GC/MS, and the comparison of fatty acids composition of the diseased juvenile with the normal juvenile was made. The fatty acids were detected, including 12 SFAs,6 MUFAs and 6 PUFAs. C14：0,C16： 0 （SFA） and C16：1,C18：1 （MUFA） were main source of energy metabolism during internal nutrition. The essential fatty acids C20：4（ n- 6）（AA） have existed in the larvae before its first feeding, while the DHA and EPA were only detected after feeding, and were affected by the bait kinds. The ranges of DHA and EPA content variety were 7.26% - 25.36% and 3.41% - 8.40% respectively. Compared with FA composition of the normal juvenile of the same period, the content of DHA and EPA in the juvenile with ＂swim bladder bnlge＂disease decreased clearly,with the DHA content being only 1/3 of the normal one, while the contents of AA,C18：1,C18：2,C18：3 and EPA/DHA specific value increased markedly,being 1.5- 3 times of those in normal juvenile. The inside reason that＂swim bladder bulge＂diseasc took place may be lack of DHA and EPA and higher AA.The research result can offer a theoretical foundation to prevent the ＂swim bladder bulge＂disease.

Abstract:A series of growth experiments was conducted to examine the effect of dietary protein on protein systhesees parameters [protein synthesis rate （Ks）, protein degradation rate （Kd） and protein accumulation rate （Kg） and protein deposition efficiency （PDE） ] in muscle and hepatopancras of topmouth culter, Erythroculter ilishaeformis Bleeker juveniles by using brown fishmeal as the protein source in formulated diets. Tested fish with initial weight （ 12.84 ?0.60 g wet weight）were fed 5 isoenergetic（20 MJ?kg^-1 gross energy ） and the same relativity of essential amino acid balance experimental semi-purified diets containing different protein levels （31.04% ,35.51% ,40.89% ,46.62% ,50.33%dry matter ） in 5% increments. And five isonitrigenous （40% protein） and isoenergefic（20 MJ?kg^-1 gross energy） and different relativity of essential amino acid balance experimental semi-purified diets with soybean protein replacing 0%, 13.5% ,27% ,40.5% ,54% of fish meal protein were formulated. After 8-week trial, The results showed that with increasing dietary protein level, specific growth rate was significantly influenced by dietary protein levels （ P 〈 0.05）. Specific growth rate of the fish fed the 40.89% protein diets was significantly higher than that of the fish fed 31.04% and 35.51% protein diets （ P 〈0.05）, but them was no significant difference from that of the fish fed the 46.62% and 50.33% protein diets （ P 〉 0.05）, Effect of dietary protein levels on protein accumulation rate in muscle followed the similar pattem as that of hepatopancras, protein accumulation rate in muscle and hepatopancras in fish fed the 40.89% protein diets were 2.13%?d^-1 respectively. The specific growth rate of the fish fed the 40.89% protein diets was significantly higher than that of the fish fed 31.04% and 35.51% protein diets （ P 〈 0.05）, but them was no significant difference from that of the fish fed the 46.62% ,50.33% protein diets （P〉0.05）. Protein synthesis rate （Ks） and protein degradation rate （Kd） in white muscle increased with the ubcrease of dietary protein level（ P 〈 0.05） ,protein increase in white muscle was much more due to the increase of Ks than Kd, the muscular protein deposition efficiency （ the proportion of growth to synthesis） had a maximal value in optimistic dietary protein level. When the replacement level for fish meal protein with soybean protein was 13.5%, 27%, 40.5%, them were no significant difference in specific growth rate among the diets compared with control group（ P 〉 0.05） ,and were significantly higher than specific growth rate in fish fed with 54% replacement of soybean protein （ P 〈0.05）. Replacement of fish meal by soybeaa cake also affected significantly the protein accumulation rate （Kg） in white muscle（ P 〈 0.05）. When the replacement level for fish meal protein with soybean protein was 40.5%, there was significant decrease of Kg compared with control group（ P 〈0.05）. When the replacement level for fish meal protein with soybean protein was 54.0%, there was significant decrease of Ks compared with control group（ P 〈0.05）. In white muscle, increased replacement level for fish meal protein with soybean protein did not change PDE （ P 〉 0.05 ）. With the increase of replacement level for fish meal protein with soybean protein, worse EAA balance decreased gradually with the growth, but the change of EAA pattern in diets did not affect PDE of white muscle.

Abstract:The mucus layer is the most outer defence barrier of fish. The bacterial attachment to mucus layer is a critical step in the host colonization and subsequent occurrence of infection. Adhesion of Vibrio alginolyticus to the intestinal mucus of Pseudosciaene crocea has been investigated in order to understand the characteristics and mechanisms involved in the adherence of bacteria onto fish mucus so that preventive measures can be devised to reduce infection. In vitro adhesion assay was carried out by bacterial counting. The adhesive bacteria were stained with SYBR Green Ⅰ , observed under fluorescent microscope, counted on computer display after taking pictures. The results showed that the adhesive quantity of V. alginolyticus increases with bacterial concentrations and reached equilibrium after being incubated 1 - 1.5 h;the higher adhesive quantity was achieved at 15 - 30 ℃ and acid condition; adhesion of V. alginolyticus to the mucus of foregut was not obvious variety with salinity（5 - 35） ,but adhesive quantity to the hindgut mucus enhances while salinity increases; V. alginolyticus could not adhere to intestinal mucus without salinity; adhesive quantity reduced remarkably after heat treatment of the germ（56 ℃ 5 min, 60 ℃ 1 h）, which indicated that heat sensitive structure of V. alginolyticus might play an important role in adhesion. The conclusions of this paper showed V. alginolyticus could adhere to intestinal mucus of P. crocea facilely in seawater; this adhesion was remarkably affected by environmental factors, such as temperature, pH and salinity; V. alginolyticus adhered to the intestinal mucus of P. crocea by specific adhesion, some heat-sensitive structures on V. alginolyticus surface played a crucial role in adherence of the bacteria to gill mucus. The results indicated that the bacterial adhesion of V. alginolyticus to intestinal mucus of P. crocea was govemable. The results obtained are useful for the epidemic control in fish culture.

Abstract:A rare kind of parasitic turbellarian, parasitizing Sciaenops ocellatus, causing serious gill damages, and causing high mortality of the host fish, was reported for the first time by our previous study at Luoyuan Bay in October 2000. The subsequent survey revealed that this disease had the characters of large scale, high incidence and high intensity. In 2002 this disease took place in a company at Zhangpu County of Fujian Province, where Paralichthys olivaceus was cultured. It was not diagnosed and controlled immediately. The infection rate was over 50%. The mortality ranged from 20% to 50%. The loss was approximately 40 million yuan. This disease also caused the death of as many as twenty thousand Pseudosciaena croceas within a week at net cages of No. 350 cultured in Luoyuan Bay. The mortality was higher than 50%. Therefore,it is urgent to study the epidemiology of this disease and to discover the method to control it. The biological characteristics of this turbellarian were studied by field survey, biostatistics, experimental infection, observation of living specimen, histological method, and so on. The results showed that the disease prevailed all over the cultural sea area in eastem Fujian, including Luoyuan County, Ningde City, Lianjiang County and Xiapu County, and southem Fujian, including Zhangpu County, Xiamen City and Tong＇ an County. This kind of turbellarian was found in both the cultural cages and the cultural tanks. It infected not only S. ocellatus but also P. crocea, Miichthys miiuy, P. olivaceus, Sparus macrocephalus and Takifugu oblongus. These mrbellarians parasitized the gill, fins and the body surface of many kinds of marine cultured fishes. They made great lesion to the place where they lodged, causing asphyxiation or the secondary infection of bacteria which resulted in a high mortality of 20% - 60%. This disease prevailed mainly in autumn, from August to November, at the water temperature of 22 - 26 ℃ and the salinity of 25 - 30. A coincidence of high incidence area and the nearby seashell culture area, such as abalone and oyster culture area, was found. The primary experimental infections showed the cornmensul associations of the turbellarian with clam and oyster. However, it needs further confirmation on which kind of mollusc could serve as the reservoir host of the turbellarian. This study could provide scientific bases to control the diseases. According to the results of survey and experiments, several treatments to the disease were provided. Cupric sulfate, formaldehyde, trichlorphon can have a certain curative measure by spilling, bathing and hanging bag in the water. The using of underwater, reducing salinity and temperature, improving nutrition and using medicine reasonably and so on were also proved to be effective in the control of the disease.

Abstract:Fish vaccines play an important role in the control of fish diseases, especially in the control of some malignant infectious diseases, such as the prevention and cure of some viral diseases like hemorrhage disease of grass carp, spring viremia of carp, infectious pancreatic necrosis, etc., bacterial diseases like furunculosis, etc., and the control of diseases happening in large waters like lakes and reservoirs, etc. ; they are also able to avoid the inefficacy of disease treatment caused by resistance of pathogens to drugs, therefore, their use in the control of fish diseases is considered as most important means by harmless fishery. The history of fish vaccines is only a little more than 30 years in China, fortunately, they went through a rapid development period and now are at a new age during which high technologies expand rapidly, vaccines evolve sharply and traditional and new generation vaccines clash repeatedly, however, still many obstacles appeared during their development, Some of which brought more difficulties to their development, such as the variation of pathogens, diversity of antigens and limited understanding of immunity functional genes; others affected their applications, such as the ambiguity of immune response mechanism, the lack of convenient effective methods and measures in administration and immunization efficacy enhancement; still others caused no commercial fish vaccines available now in China, such as the failure in the establishment of effective evaluating systems and methods. Hence, it points out in this review that first, the development trends of vaccinology must be catered for by researchers; second, basic theories of fish vaccinology should be further perfected; then, the application and innovation offish vaccines in China should be further intensified by means of one or two grave aquatic animal diseases successfully cured; and then, the development of traditional vaccines and that of new generation vaccines should be combined; finally, in order to quicken the development of fish vaccines, new technologies should also be applied to their development of fish vaccines, depending on the research achievements of human and animal vaccinology.

Abstract:Biogenic amines are basic nitrogenous compounds with low-molecule-mass, and occur universally in animals, plants and femented foods. Biogenic amines possess the function of physiology and toxicity. Biogenic amines are formed by decarboxylation of their precursor amino acids, as a result of the action of either endogenous amino acid decarboxylase activity or by the growth of decarboxylase positive microorganisms. The content of biogenic amine depended on the characteristic of food and the varieties of microorganisms in it. A lot of proteins existed in aquatic products, and peptides and amino acids were produced in the course of processing and storing. Subsequently biogenic amines were transformed easily by these low-molecule-mass matters. The varieties and the biosynthetic mechanism of biogenic amines, and the factors affecting the formation of biogenic amines in diferent aquatic product were summarized. The analytical methods for the detemfining of biogenic amines were introduced, and the control measures preventing the formation of biogenic amines were discussed.

Abstract:Sanggou Bay is one of the most important cultural areas in China. The scallop Chlamys farreri is a dominant cultural species in this Bay. To examine the effect of the cultural scallops on the suspension particle organic carbon （POC） of the Bay, field surveys on the living environmental conditions of the scallop in the bay were conducted in spring in 1999 and 2000. The main parameterclearance rate that can respond to the physiological condition of scallop was measured in laboratory. The clearance rate was determined using the method of food degression in static system. Meanwhile, the relationship of clearance rate and temperature that changed from 1 ℃to 30 ℃ was measured in the experiment. Results showed that the relation of clearance rate and temperature was same as Gaussian curve, and the relationship can be expressed as the following ： CR = {234.7 ? [ 7.17 ? （ 6.283）^0.5 ] } ? EXP { - 0.5 ? [ （ T ? 22.14） ? 7.174）^2}. The average concentrations of POC in May and April were 432 μg? Cl^-1 and 139.92μg? Cl^- l, respectively. The range of primary production in May and April of the bay were 79.3- 220.8 mg?cm^-2?d^-1 and 57.2- 196.6 mg?cm^-2?d^-1 respectively. In respect of the temperature of sea water, there was no significant difference among the stations in April, but difference was observed among the stations in May（ P 〈 0.05）. The grazing impacts of the cultural scallops on POC stocking in May and April were between 10.2% - 73.4% and 6.2% - 25.2%, respectively; the mean grazing impacts were 40.8% and 18.8%, respectively. 10.9 % -49.9% and 39.8 % - 186.2 % stocking of the carbon coming from primary production were circulated into the main food web through scallop filtration in April and May respectively. There are significant differences between the stations and temperature is the mainly reason causing the difference.

Abstract:The consumption of seafood is widespread in China. The increase in the rate of seafood allergies, as well as their persistence and severity, become an important food safety issue. To improve seafood allergy patients＇ life quality, it is important to find a kind of seafood which has little or even none allergens. Different kinds of seafood live in different circumstances, it may have different allergens. This study compared the difference among varieties of shrimp. In the experiments, three kinds of shrimp were selected and the protein profiles were analyzed using SDS-PAGE. Then Immunoblotting and EAST inhibition were used to determine the allergenicity of them. The results show that main allergens of the three kinds of shrimp have molecules - 36 kD, similar allergcnicity, and critical cross-reactivity.

Abstract:This paper described the preparation and characterization of monoclonal antibodies （Mab） against mandarin fish（ Sinipewa chuatsi） immunoglobulin（Ig）, using the Mabs as a tool for analyzing the structure of S. chuatsi Ig, and monitoring the humoral immunity level of S. chuatsi. The purified serum Ig of S. chuatsi was used as antigen to immunize Balb/C mice, after cell fusion and screening the antibody secreting cell, eleven hybridoma cell lines which secreting Mab against S. chuatsi Ig had been established. The characteristics of these Mabs had been analyzed. In isotyping analysis, the results showed that two of them were IgM, three of them were IgG3, five of them were IgG1 and one of them belonged to IgA; Further experiments proved that Mab 7F12-F6 only specifically bound to the Ig of S. chuatsi; MablF12-A3,4D3-A7,3F8-H3,3A5-D11,5C3-A7,5D11-F9 and 6G6-All were able to recognise the Ig of S. chuatsi, Anguilla anguilla and Auguilla japonica. And Mab3D5-H7,3D3-A6,4Cl-H11 had the cross reaction with the Ig of A. anguilla, A. japonica and Colossoma brachypomum. All of Mabs did not have any cross reaction on the Ig of Pseudosciaena crocea, Epinephelus drummondhayi, Carrassius auratus, Hybrid tilapia, Clarias fuscus, ornamental carp, Micropterus salmonoides and the fish common bacterial pathogens, such as Aeromonas, Edwardsiella, Vibrio, Salmonella and Escherichia coli. And their ELISA titer ranged from 104 to 106, the sensitivity of the Mabs purified Siniperca chuatsi Ig was at least lower than 39 ng? mL^ - 1. These results suggested that the different fish species had both species specific epitopes and the common epitopes on their Ig. These common epitopes not only existed between the close relative species, such as the Japanese eel and European eel, but also existed between the distant relative ones such as S. chuatsi, eel and C. brachypomum cuvier. The studies revealed that the Ig of S. chuatsi had evolutionary relationship with the Ig of eel and C. brachypomum cuvier, and the specific Mab has the potential to be used for detecting the humoral immunity level and the pathogen of S. chuatsi.