Abstract:Cross experiments between the artificial pigmentation mutants and the wild type in Porphyra haianensis Chang et Zheng, were＂ carried out to examine the occurrence of meiosis in its life history, according to the appearance of color segregation and colorsectored blades in the F1 gametophytic blades developed from the conchospors of the heterozygous conchocelis. Two red types of pigmentation mutants （ SPY- 1 and R-10） were used as female parent, and their blades show red or red orange in color, thin and weak elasticity and have no denticles on their marginal parts. The wild type （wt） was used as male parent, and its blades show wild-type color, thick and good elasticity and have many marginal denticles. Among the Fl gametophytic blades from the crosses of SPY- 1 （ ♀ ） ? wt（♂） and R - （ ♀ ） ? wt（♂）, two parental colors （R and W） and two new colors （R＇, fighter in color than R; W＇, wild- type-like color and redder than W） appeared. Linear segregation of colors occurred in the blades, and therefore, the color-sectored blades with 2 - 4 sectors were formed. In the color-sectored blades, the sectors of R and R＇ were thinner than sectors of W and W＇, showing weak elasticity and without marginal denticles. However, the sectors of W and W＇ were thick, showing good elasticity with many marginal denticles. 95.2% -96.7% of the F1 gametophytic blades were color-sectored blades, and only 3.3% -4.8% of them were single-colored blades. These results indicated that the meiosis of P. haitanensis occurs during the first two cell divisions of the germinating conchospore, and thus it was considered that the initial four cells of the developing sporeling constitute a linear genetic tetrad leading to the formation of the color-sectored blades. The new colors of R＇ and W＇ were recombinant colors because the occurrence of chromosome recombination during the first cell division of the meiosis. It was certain that the color phenotypes of two mutants used in this paper resulted from two or more mutations in different genes, and that they also have mutations relative to blade thickness and formation of the marginal denticles, which is linked with color mutations. The recombinant colors of R＇ and W＇ were better in contents of chlorophyll a （ Chl. α ）, phycoerythrin （PE） and phycocyanin （PC）, and growth and maturation, indicating that the improved varieties probably could be obtained through crosses between the pigmentation mutants or between the pigmentation mutant and the wild type in P. haitanensis.

Abstract:Vibrio harveyiis a causative agent of vibriosis that infects large yellow croaker（ Pseudosciaena crocea） as well as some other marine fish and brings severe loss to their culture. The development of vaccines against vibrio is recognized as a priority to the complement of existing control measures. Recent studies emphasized the role of the outer membrane protein （OMP） of pathogenic bacteria in protective anfigenicity. A target of protective immunity, OmpK, is the receptor for KVP40 which is a broad-host-range vibriophage. To investigate the possibility of OmpK as vaccine candidate, primes were designed according to OmpK gene sequence published in GenBank, and a piece of DNA sequence about 800 bp was amplified by PCR from genomic DNA of V. harveyi isolated fi＇om infected P. crocea. The gene was cloned into pGEM-Teasy vector and sequenced. The Blast alignment result indicated that it was indeed the outer membrane protein（OmpK） gene of V.hameyi. After its signal papfide sequence was discarded by PCR and the remains was inserted into E. coli expression vector pGEX-4T-2, a fusion expression vector pGEX-4T-OmpK was constructed, which can amply the expression of a 53 kD fusion protein GST-OmpK in E. coli BL21 when induced by IPFG. The fusion protein was purified and used as antigen to immunize the New Zealand rabbit, the antiserum with high antibody value was acquired. The Western-blotting shows that the anti-recombinant OmpK serum can specifically react to the 27 kD comtponent of natural Omps extracted fi＇om V. harveyi. This result indicates that the OmpK may be one of the important protective antigens of V. harveyi, and may play a role in protecting fish from infection of V. harveyi.

Abstract:Hyriopsis cumingii, which produces pearl oftbe highest quality, is a kind of freshwater species unique in China. The development of microsateUite markers of H. cumingii has not been reported. However, many microsateUite markers have been developed from Crassostrea gigas. The conservativeness of the side sequences of the microsatellite in species of close genetic relationship has already been discovered. In order to determine the applicability of micmsatellite primers developed from C. gigas to genomic analysis in H. cumingii, 32 polymorphic micmsatellite primers identified in the Pacific oyster were employed to amplify in the genome of mussel. The conditions of polymerase chain reaction（PCR） were optimized for the fidelity of DNA synthesis during PCR amplification. It was found that 19 loci failed to be amplified and 13 loci （about 41% ） amplified specific products successfully. Among 13 loci, 3 （Cgi-6, Cgi-27and Cgi-28） were monomorphic and 10 （about 31% ） （Cgi-l,Cgi-10,Cgi-18,Cgi-22,Cgi-24,Cgi- 25, Cgi-26, Cgi-29, Cgi-30 and Cgi-32） were polymorphic. The analysis of the genetic diversity showed the average heterozygosity of l0 microsateUites loci of H. cumingii ranged betwen 0. 125 and 0.693 and 7 loci （Cgi-10, Cgi-22, Cgi-24, Cgi-26, Cgi-29, Cgi- 30, Cgi-32 ） are high polymorphic（He 〉 0.500）, whereas 3 loci （Cgi-1, Cgi-18 and Cgi-25 ） are low polymorphic（He 〈0.500）. This study confirmed that 10 Pacific oyster pimers could be used for the analysis of the genetic diversity in H. cumingii. This result showed some of the microsateUite primers can be used for genetic analysis of mussel without high coat costing and time consuming. And it suggested that this method could be useful in genetic analysis of other species of mussel.

Abstract:Using artificial spawning and dry insemination, two hybrid experiments between cyprinus carpio vat. specularis ♀and Mylopharyngodon piceus ♂ were conducted. A total of 8789 thousand fertilized eggs and 3580 thousand 4-day old larvae were obtained. The fertilization rate was 94.15% and the hatching rate was 51.4%. The fertilized eggs took 5 min after fertilization to develop into formation of blastoderm, about 58 min into 2-cell, 1 h 10 min into 4-cell stage , 1 h 25 min into 8-cell stage, stage 1 h 43 min into 16-cell, 1 h 53 min into 32-cell stage, 2 h 20 min into morula stage, 2 h 49 rain into early-blastula stage, 4 h 30 min into middle- blastula stage, 5 h 18 min into late-blastula stage, 6 h 30 min into early-gastrula stage, 7 h 30 min into middle -gastrula stage, 9 h 30 min into late-gastrula stage, 10 h 20 rain into neurula stage , 12 h 00 rain into blastopre closing stage, 14 h 30 min into optic vesicle stage, 18 h 20 min into tail-bud stage, 23 h 30 min into eye lens formed stage, 25 h 00 min into muscular effect stage, 27 h 55 min into heart working stage, the hatched larvae stage was from 40 h 33 min to 45 h 30 rain after fertilization. The embryonic development was observed until the fourth day then the 4-day old larva were put into the pond for breeding. The embryonic development time of the hybrid is between their parents＇. Meanwhile the abnormal phenomena from fertilized eggs division, organ forming to hatched larva during each embryonic development stage of hybrid were observed. The malformation rate was 51.8%.

Abstract:Artificial diploid gynogenesis, a form of all-female inheritance, was considered as one of the most effective techniques for the rapid establishment of inbred lines, mono-sexual broods or clones, as well as for examining sex-determination and gene-centromere recombination. Induction of gynogenetic diploid in many mollusks has been performed recently, but few cytological studies have depicted the fertilization and early cleavage events in eggs inseminated with ultraviolet （UV）-irradiated sperms. The aim of the experiment was expected to examine the differences of nuclear behavior on early development between normal and artificially induced gynogenetic diploid eggs of Chlamys farreri. In this study, a large number of gynogenetic diploids in Chlamys farreri were generated by activation of eggs with UV-irradiated spermatozoa and subsequent diploidization of the maternal chromosome set by blocking the second polar body extrusion. The optimal dose of UV light irradiation at intensity of 800 μW?cm^- 2?s for 50 s and the best treatment condition of 60 mg?mL^-1 6-dimethylaminopurine（6-DMAP）for 20 rain were obtained on the basis of the preceding trials. Then, to treat normal and gynogenetic diploid eggs of C. farreri fixed in Bouin＇ s fixative, nuclear changes were observed carefully under an optical microscope during fertilization and early cleavage. The results of cytological observation indicated that the female and male pronuclei of normal eggs fused into zygotonuceus, but their behaviors of gynogenetic diploid eggs were considerably complicated. The sperm nucleus of gynogenesis had at least two situations： One was that it kept dense and could not develop into male pronucleus, and another was that it expanded again after the second meiosis but did not reach its maximum as a normal male pronucleus. In the process of the first and second cleavages. The sperm nucleus of gynogenesis, which became a dense chromatin body （DCB）, did not participate in the karyokinesis and was located between the two maternal chromosomes. At the completion of cleavage, DCB was seen either in the region of the first cleavage furrow or in the cytoplasm of one of the two blastomeres. Treatment with 6-DMAP, the formation of the second polar body was inhibited effectively and diploid female pronucleus was formed. In addition, the phenomena of polysperm and polyspindles in the experiment were also observed and analyzed.

Abstract:Using hematology analyzer, hematological parameters of 5 age groups （ 1 - 5 years old） of cultured Amur sturgeon, Acipenser schrenckii, were studied. Blood samples were collected using 5 mL medical injectors from the artery or vein near the anal fin of the fish, and the samples were put into tubes with anticoagulant for examination. For each age group, 5 individuals of fish were sampled. Before blood sampling, fish was immobilized using MS-222 at the concentration of 200 mg? L^-1. Examination data were analyzed using software STATISTICA version 6.0 （ Statsoft, Inc. ）, and using one-way ANOVA to test the significance of group differences, using LSD for multi comparison, and using GRM for the correlative analysis. The examination results showed that red blood cell （RBC）, haematocrit （HCT）, hemoglobin （ HGB ）, mean corpuscular hemoglobin （MCH）, mean corpuscular hemoglobin concentration （MCHC）, white blood cell count （WBC） increased with the age. WBC and HCT of 5 years old group were significantly higher than that of 1 - 4 year-old groups （ P 〈 0.05 ）, however, there was no significant difference of HGB, MCH and MCHC among all groups. Among 1 - 4 year-old groups, there was no significant difference in mean corpuscular volume （MCV）, platelet （PLT） count and hemoglobin distribution width （HDW）, but the MCV and PLT of 5 years old group increased significantly and HDW reduced significantly. RDW did not change much with the age, but mean platelet volume （MPV） slightly reduced with the age. For the change of differential leukocyte count （DLC）, the proportional order of the number of different kinds of cells in the leucocyte indicated lymphocyte （Lym） 〉 basophil （Baso） 〉 neutrophil （Neut） 〉 monocyte （Mon）. With the increase of age and Lym reduced, however, Baso and Mono increased. Comparison with other fish species, HCT and RBC of Amur sturgeon were lower than that of most freshwater fish species. MCV of culaued Amur sturgeon was lower than those of wild ones, but MCHC of culaued Amur sturgeon was much higher than that of wild ones. This result is similar to the test of rainbow trout and tilapia. Lym number of culaued Amur sturgeon was high, so was that of the most fish species. Similarly, Baso number of culaued Amur sturgeon was high also, just below the Lym number. This is quite different from that of most freshwater fish species. MCV, PLT and HDW of 5 years old culaued Amur sturgeon were significantly different from those of 1 - 4 year-old groups. This result may imply that these parameters may be related to the age of maturation because 5 years old culaued Amur sturgeon reached maturity.

Abstract:Based on the continuous samples of the larvae development of Harpiosquilla annandalei Kemp, the morphology and the development features were observed under microscope and dissecting microscope and their pictures were drawn. The result showed that after experiencing 11 molts at water temperature 24 - 27 ℃ and salinity 25.4 - 29.0, the pseudozoea of H. annanda/ei. . metamorphose into juvenile squilla and this process takes 49 days to complete. The body length at pseudozoea Ⅰ is 1.75 - 1.83 mm. Its head has a long rostrum. The shape of the carapace with one pair of ventral teeth in edge, a spine in each comers and a long spine in the middle of retral part is similar to a turtle shell. At pseudozoea stage Ⅵ, the carapace with 5 pairs of lateral abdomen teeth in edge gradually developed, and then looks like a trapezium. The mesial flagellum bud appears on the first antenna and the endopodite in the second antenna develops into a short bud. The telson appendage presents when the larva develops into pseudozoea Ⅶ. The two edges of carapace begin to bend and cover downwards when the larva is pseudozoea Ⅶ. At pseudozoea Ⅺ, its body length is 15.10- 17.20 mm. The endopodite in the second antenna develops and become a long flagellum divided into 14- 16 segments. The exopodite of telson has 2 segments and the endopodite has 1 segment. The body length of juvenile squilla at stage I is 14.5 - 16.10 mm. The long rostrum disappears and the carapace is still in trapezium shape while smooth and without ventral teeth. Its anterior cumu is rounded and its posterior comu has two nicks which are the distinguishing feature for this species. Then the mid spines in the retral carapace disappear. The rate of carapace length compared to body length decreases obviously. The larvae in this stage look like a miniature adult squilla. The larval morpha of H. annandaiei has some differences from those of O. kempi and O. oratoria. The differences can be identified by the rate of the carapace length compared to the body length, the rate between the length and width of carapace, the scale seta numbers in the second antenna and the lateral, mid, sub-mid tooth numbers in the telson.

Abstract:Big-eye mandarinfish Sirdperca kneri is a commercially valued species that naturally lives in the Pearl River water system and the Yangtse River upriver water system. In order to study the reproductive biology of S. kneri, 322 mature individuals captured from the Pearl River water system were measured. By means of biological survey and experimental ecology, the annual change of development of gonad and gonadosomatic index （GSI）, the percentage of gonadal maturity and the fecundity of this fish were determined. And the whole process of embryonic development was observed and photographs were taken continuously. Based on the annual change of gonadosomatic index （GSI） and percentage of gonadal maturity in whole year, it was concluded that the reproductive season of the S. kneri was from April to August, with a busy season from May to June. The individual absolute fecundity ranged from 11 036 to 106 022 eggs, increasing with the body length and body weight and age increased. But the individual relative fecundity did not change even if the body length, body weight or age changing, and kept the level of 100 eggs per gram or so. The eggs of the fish was buoyant and the diameter was 1.2- 1.5mm. There were several or dozen guttules in the yolk sac, and only one was even bigger among them. At the temperature of 24 - 25 ℃, the fertilized eggs hatched to fries in about 69 hours and 23 minutes. These results would provide the imtportant scientific basis for the large-scale artificial reproduction and protection resources of the fish. And the optimal season of artificial reproduction is from May to June.

Abstract:The opinion that the specific dynamic action （SDA） is caused by the growth of animals dominates the studies in this field. But there are still evidences for the positive correlation between SDA and feeding. In order to investigate the relation between the growth and SDA of Chinese shrimp, Fermeropenaeus chinensis, three experiments were designed. In the first experiment, shrimps of four different body weight were fed with formulated diet at different ration levels for 28 d and the data of growth, food ingestion, and exuviations were acquired. In another experiment, the shrimps were fed with six different diets （fish muscle, shrimp muscle, clam muscle, polychatte worm, formulated diet, and an equal mixture of them） for 30 d and the same data as the first experiment were acquired. Then the energy budget of the shrimp in each experiment was constituted. The respiration energy consumption of Chinese shrimp was calculated using methods of reckoning from energy budget respectively and the energy cost of growth after ingesting formulated diet was calculated. It was found that the energy cost of 1 g wet weight, l g dry weight, 1 g protein, and 1 kJ energy body weight gain were 12.660- 17.785 kJ, 21.600-31.292 kJ, 31.572- 45.537 kJ, 1.089- 1.453 kJ, respectively, when the shrimp fed with formulated diet. The compound relationship among body weight （W）, weight gain （G）, and energy consumption （Re） was well simulated with equation Re= r? G＋ b? Wc. It was inferred that the energy cost of Chinese shrimp was higher than fishes after comparing the data of the present experiment with previous studies on fishes. Significant differences were found among the energy costs of unit body growth of the shrimp fed with different feed. Shrimps fed on polychaete worm expended least energy and shrimps fed on fish flesh consumed most energy for unit body growth. It was found that food conversion efficiencies （ FCEd, FCEp and FCRe） were highest at polychatte worm fed shrimps and the poorest food conversion efficiencies were observed in fish flesh fed shrimp. The relationship between the apparent specific dynamic action and growth was explored. It is indicated that the energy allocated to growth was negatively related to the apparent specific dynamic action, thus indicating that the growth of animals was not the direct causal factor for apparent specific dynamic action. A credible explanation of the nature of SDA is still in need. To achieve this explanation, further studies to understand the energy cost of feeding and the energy expense of growth simultaneously must be conducted.

Abstract:This experiment was conducted to investigate the effects of three different temperatures and salinities on spermatophore regeneration and sperm quality in shrimp Litopenaeus vannamei. The spermatophores weights were weighed and sperm qualities were evaluated through dyeing and observing under fight-microscope when shrimps were cultured in different temperature and salinity conditions. Results showed that total sperm count and normal sperm count of shrimps held at 26 ℃ were significantly higher than that of shrimps at 22 ℃ and 30 ℃. Normal sperm count of shrimps held at 30 ℃ reduced from 14.0 million to 4.3 million, and abnormal sperm increased from 6.1% to 56.6%. The higher the temperature was, the shorter the intermoult cycle became, but the sperm quality of shrimps maintained at higher temperature （30 ℃ ） was worse than those of shrimp at lower temperature （26, 22 ℃ ）. Spermatophore weight of shrimps held at a salinity of 30 was significantly higher than those of shrimp at 5 and 15, but total and normal sperm count of shrimps held at a salinity of 15 was significantly higher than those of shrimps at 5 and 30. With the experiment period lasting, percentage of abnormal sperm of shrimps held at three different salinities increased, especially at 5. The research will he helpful to the shrimp hatcheries for shrimp reproduction in male broedstock selection and culture.

Abstract:The relationship between the diversity of protozoan community and water quality in ponds for the culture of Siniperca chuatsi was studied through the detection of pond water physicochemical factors and the observation of plolyurethane foam unit（PFU） protozoan community. The experiment was conducted from September to November in 2004 at Shunde, Guangdong Province. Water physicochemical factors were determined by common method and water quality index was constructed according to GB3838 - 88. Protozoan samples were collected by PFU method and protozoan community diversity index was calculated by Margalef formula. The results showed that some factors such as TN （ NH4 - N, NO2 - N and NO3 - N） and chemical oxygen demand （COD） increased gradually as cultivation progressed. The results also showed that the water quality index increased in cultivation progress. The opposite trend was observed for the diversity of protozoan community. The water quality index and protozoa community diversity index can he used for evaluating water quality. The relationship between PFU protozoan community diversity index（y） and water quality index（ x ） could be expressed by y = 2.45 - 2. 54Inx, that is to say, the higher water quality index is, the lower the protozoan community diversity index is. Through correlation and regression analysis, coefficient of correlation and regression is significant at 0.01 level. It is also found that there is a relationship between protozoan community diversity index and S. chuatsi diseases. Protozoan community diversity index would become a good biofactor for prediction of S. chuatsi diseases.

Abstract:A study on the effect of stocking density and water temperature on the growth of juvenile white spot pike Esox lucius was conducted. During the expedraental period, water temperature, pH, dissolved oxygen （DO） and ammonia- N level were measured once a day respectively. The major environmental factors were controlled at the same levels in each experimental tank where DO was beyond 5.5 mg? L^-1. White spot pikes weighing （20 ?0.31 ） g（ mean ?SE） were reared in different stocking density（ 8, 16, 24, 32 and40 ind?m^- 3） and water temperatures（18 ℃,21 ℃,24 ℃,27 ℃ and CT）in greenhouse for 30 days. At the end of the experiment, fishes were weighed and data analyzed by ANOVA and correlation methods using SPSS software. Growth performance of the fish was significantly affected by water temperature and stocking density. Daily weight gain, specific growth rate, growth efficiency,ration were significantly decreased with increasing densities, maximum SGR（6.282 ?0.022） occurred in 8 ind?m^- 3. But for net yield, they were much higher in group 24 and 16 ind?m^- 3; With temperature increased, daily weight gain, specific growth rate, growth efficiency increased firstly and then decreased, and reached a maximum （ SGR = 5. 667 ? 0. 041 ） at 24 ℃. There was significant（ P 〈 0.01 ） negative correlation between density and SGR [ SGR = 7.30 - 0. 122SD, r^2 = 0. 9927 ], and there was significant correlation between temperature and SGR[SGR = -0. 047T^2 ＋ 2. 169T- 19.56, r^2 = 0. 8342]. Based on the regression equation, the fish achieved the biggest SGR （5. 396 % ） at 23.11 ℃. Compared with previous studies, the optimal water temperature is generally lower for white spot pike cultured in greenhouse, and it can be raised in greenhouse successfully if the water temperature and stocking density are well controlled. During the experiments living food were fed, but commercial food for white spot pike is still a problem to be solved.

Abstract:The sulfide in rnariculture environments could not only influence directly the seawater environmental qualities and result in impairments of the organisms cultured, but also induce the aging of rnariculture environments. In this paper a simulation experiment was carried outto study the effect of clam （Ruditapes philippinarum） culture on the acid voatile sulfide（AVS） in sediments and to analyze the relations between AVS and other experimental factors. The aim of this study was to offer theoretical base for ecological rehabilitation in aging mudflat of mariculture areas. In this paper the experimental ecology method was used in laboratory. The period of the simulation experiment persisted for 4 months from August 23 to December 24 in 2003. The experiment site was located in the scientific base of Yellow Sea Fisheries Research Institute in Xiao-maidao, Qingdao. The 7 plastic experimental containers（60 cm ?35 cm ? 25 cm） were filled with 15 cm mud fetched from Rushan Bay. The mean weight and length of the clams tested were 5.87 g and 3.19 cm respectively. The clam culture densities were classified into high （5 233 g?m^-2）, middle （3 733 g?m^-2）, low （2 233 g?m^-2） densities and the control （0 g?m^-2）. The intervals of the sampling were 10 day （3 times）, 15 day （4 limes） and 30 day respectively. The items of determinations included AVS, temperature, redox potentials （Eh）, organic matter （OM）, active iron, heavy metals, sulfate reducing-bacteria （SRB） and the simultaneous extracted metals （SEM）. The mean values were used to illuminate the effect of clam cultures on the AVS. The results showed that the clam culture activities could affect the concentration of AVS. The AVS concentrations of the 3 tests were higher than that of the control, and he.came higher with the increase of the culture densities. Meanwhile, the tendencies of the AVS concentration were just the same at different temperatures.The relation between Eh and AVS was negative correlation, the coefficients of them in middle and high densities tests were r = -0. 6867（ P 〈 0.05 ） and r = - 0.6621 （ P 〈 0.05）, respectively. The relation between OM and AVS was positive correlation, the coefficients of them in high densities tests was r = 0. 6919 （ P 〈 0.05）. Both of the highest value of Fe^3＋/Fe^2＋ and the concentration of AVS appeared at the middle of the experimental period. The relation between SRB and AVS was positivly correlated, the coefficient of them in low and middle densities tests were r = 0.7591 （ P 〈 0.05 ） and r = 0.8317 （ P 〈 0.05 ）, respectively. The values of SEM/AVS among all the 3 tests and the control were lower than 1. It was concluded that the clam culture could increase the concentration of AVS in the sediments, and that the concentrations of AVS became higher with the increase of culture density. It was the values of temperature, redox potential, organic matter, Fe^3 ＋/Fe^2 ＋ and the number of sulfate reducing-bacteria in the sediments that were correlative with the concentration of AVS. The clam culture induced decrease in the ratio of SEM to AVS, which became lower than 1, so that the biological activity and/or toxicity of these heavy metals were restricted. There are many factors that may affect AVS in shellfish culture environments. To quantify the relationships among them exactly, a lot of field mud flat simulation experiments need to be practiced.

Abstract:Large（394.5 - 401.8 g）, middle（283.8 - 324.3 g）and small（94.5- 112.3 g） flounder（ Paralichthys olivaceus ）juveniles were stocked into 8 tanks of each 10.0 m ? 10.0 m ?0.8 m and fed the diets containing Chinese herbs including Lonicera japonica Thumb, ginseng root, and hawthorn at a water temperatures of 16 - 22℃ for 28,56 and 83 days, respectively. The results showed that the large, middle and small fish fed the diet containing Chinese herbs had significantly 22.4 %, 18.9 % and 2.9 % （ P 〈 0.05） higher specific growth rate, 3.0% - 36.4% ,23.53% and 11 . 1% （ P 〈 0.05） higher feed conversion efficiency and 20.77 % , 4.26 % - 39.42 % and 12. 14 % lower feed conversion ratios than the control fish, respectively. There were 11.66% , 13.49% and 9. 13% higher pepsin activities in the stomach and 11.3%, 16.64% and 8.55% higher proteinase activities（ P 〈 0.05） in the intestines in the large, middle and small fish fed the diets containing Chinese herbs than those in the same size fish in the control, respectively. For the amylase activities, however, there were no significant differences among the treatment groups（ P 〉 0.05）. The superoxide dismutase （SOD）activities were 9.53%, 9.09% and 15.14% （ P 〈 0.05） higher in the large, middle and small fish fed the diet containing Chinese herbs than those in the same size fish in the control, respectively, while the lysozyme activity and total protein contents were found not significantly different in the serum among the experimental groups.

Abstract:The research of probiotics for aquatic animals is increasing with the demand for environment friendly aqnaculture. The probiotics were defined as live microbial feed supplements that improve health of man and terrestrial livestock. Most attempts to propose probiotics have been undertaken by isolating and selecting strains from aquatic environment. These microbes were vibrionaceae, pseudomonads, lactic acid bacteria, Bacillus spp. and yeasts. Some corrunercial products are referred to as probiotics used in eel culture, though they were commercial preparations devised for land animals. This paper focuses on selection of probiotics from bacterial strains which were isolated from intestinal tract of cultured healthy eels （ Anguillla anguilla and A. japonica）, then use the selected probiotics as supplement of eel feed. 477 bacterial strains of intestinal tract of cultured eel were used for testing the antagonistic against Edwardsilla tarda, Vibrio anguillarum Non O1 Vibrio cholera, Acinectobacter lwoffii, Aeromonas hydrophila and Aeromonas sobria etc. commonly eight strains of pathogenic bacteria of of cultured eel, and gelatinase, lipase, amylase, lecithinase, casease and chitinase production. 47 bacterial swains were selected as candidates. Then, by evaluating the BOD value of the 47 strains in the liquid eel-feed-medium, 19 bacterial strains which could effectively using eel feed as their nutrients for growth were selected as candidates. After identification, 5 strains as Pseudomonas cavie, P. stutzeri, P. fluorescens （ 2 strains）, Staphylococcus lentus were pathogenic bacteria to cultured eel, 5 strains were no identification, these isolations were abandoned. Selected one strain from two Bacillus subtilis isolations and two Bacillus pumilus isolations, combined with other isolations, 7 bacterial strains were selected as candidates. By tested the degrade fish meal and tested free amino acid of 7 candidates, strain A40209CDC4 and strain A31009NA were selected as probiotics for supplement of eel feed. By oral administration （A31009NA） and injection infection （A40209CDC4 and A31009NA） test, the results of acute toxicity to European eel showed that there were no toxicity to European eel in 7days at dosage 10^9CFU?mL^-1 concentration of strain A40209CDC4 and strain A31009NA. Strain A40209CDC4 and strain A31009NA used as supplement of formulated eel feed at dosage 10^6 CFU?g^-1, the test eel was cultured at 22 ? 1 ℃, 100% water changed daily for forty days, the digestibility of dry matter and crude protein increased 30.96 and 10.04 percentage of strain A40209CDC4 respectively, and the digestibility of dry matter and crude protein increased 42.96 and 13.11 percentage of strain A31009NA respectively. From all of test items, the selected isolations were suitable used as probiotics for eel. The exploration and application of the selected isolations using as supplement of eel feed were significant.

Abstract:An epizootic in seawater cage-reared large yellow croaker, Pseudesciaena crocea, in China from September to November 2003 was caused by a Nocardia sp. The cumulative mortality was 15% and diseased fish were 16 months old with total length from 20 to 30 cm. Multiple, white nodules, 0.1 - 0.3 cm in diameter, were scattered on the heart, spleen and kidney. The morphology of isolated bacteria from Lowenstein-Jensen medium （LJM） and trypfic soy agar （TSA） were Gram-positive, branching, bead-like or long, slender, filamentous rods. Experimental infection indicated that the isolated bacterium was pathogen responsible for the mortalities and the bacterium colonizes the fish via skin or gill, and intragastric exposure to the pathogen was less effective as a route of infection. Based on the symptom of diseased fish and the growth characteristics, morphological, physiological, and biological properties of the bacterium, the isolated were identified as Nocardia sp.

Abstract:The results of pathological research in haemolymph on WSS of Litopenaeus vannamei are as follows： pathological changes in WSS are evident and similar among diseased shrimps by different infecting manner. First, total haemocyte count in diseased shrimps is lower heavily than that in healthy shrimps. The percentage of the hyaline cell in diseased shrimps is lower heavily than in healthy shrimps. The percentages of small and large granule haemocytes of diseased shrimps are all higher heavily than those in healthy shrimps. Second, the main micro-pathological changes of haemocyte showed that there was an abnormal distribution of hemocytes in haemolymph smear from diseased shrimps. Broken and disintegrated cells can often be seen in the haemolymph smear. Third, the ultla-micro-pathological changes showed that there were necrotic changes in every kind of haemocytes, and there were atypical apoptosis phenomena in certain hemocytes; There were also many WSSV in certain hemocyte nucleus. All above showed that hemocyte cell was the main target cell of WSSV.

Abstract:An indirect Enzyme-Linked Immtmosorbent Assay （ELISA） for the rapid diagnosis of Vibdo parahaemolyticus, the pathogen of the red body disease of Litopenaeus vannmei, has been developed. The best working concentration of antigen and antiserum were 10^6 CFU?mL^-1 and 1：2000 separately, determined by using checkerboard titration. The sensitivity of the serum was tested, and the lowest V. parahaemolyticus suspension was 10^4 CFU. Cross reactions of antisera with other bacteria were detected, all results were negative. Inhibition rate was 75.88 % in inhibiton test. The cross assay and the inhibiton assay indicate this method is differential. The method was optimized to detect the infected Litopenaeus vannamei and the normal ones, the positive detecting rate were 93.3 % and 13.3% separately. The results indicated that this assay can be used to detect not only the infected unhealthiness of L. vannamei, but also the carriers. This is very important to diagnose the disease in the early stage.

Abstract:The temperate sea cucumber species, Apostichopus joponicus, naturally distributed in Bohai Bay and Yellow Sea, is a valuable one due to its nutritional and medicinal properties. In recent years, sea cucumber aquaculture has developed rapidly along the northern coast of China, while the expansion and intensification of A. japonicus farming has led to the occurrence of some diseases. In the spring of 2003, the cultured sea cucumber suffered from serious disease in many farms along the coast of Qingdao, Shandong Province, which was infectious and lethal, causing 30% losses around the area. The symptom displayed as anorexia, shaking head, mouth tumidity, viscera ejection, general atrophy, and skin ulceration, the disease was tentatively termed as ＂skin ulcerative syndrome＂. The bacterium KL-1 was isolated from the focal area of the infected sea cucumber, and it was dominant amongst the isolates. Artificial infection test proved that KL-1 was the causative pathogen associated with the disease. The bacterium KL-1 was identified as Vibrio splerdidus, by the means of morphological, physiological and biochemical tests, and 16S rDNA sequence analysis. This paper revealed for the fisrst time that the causative pathogen leading to the mass mortality of the sea cucumber in the area, which will be helpful in the disease control and health management during sea cucumber cultivation.

Abstract:In this study, ATP and its related compounds, free amino acids, polyamines and monoamines, glycogen and glycolytic intermediates and organic acid were analyzed in the dorsal, ventral and caudal muscles of snakehead Channa argus together with the liver and gonad immediately after death. Total levels of ATP and its related compounds in the muscle ranged from 7.5 μmol?g^-1 to 8.0μmol?g^-1. ATP concentrations were 3.9,4.1 and 4.7μmol?g^-1 in the dorsal, ventral and caudal muscles, respectively. ATP level was high （63 % ） in the caudal muscle which moves hard. Small amounts of adenosine was detected in the liver together with inosinic acid. It can be considered that there exist two metabolic pathways of ATP degradation in the liver of snakehead. The total amounts of free amino acids were 436.0,405.0 and 356.3 mg?（100g）^-1 in the dorsal, ventral and caudal muscles. Taurine and glycine were major free amino acids and accounted for 68% to 73%. Alanine and glutamic acids were detected in fairly large amounts. Spermine and spermidine were detected in fairly high amounts in the muscle. In the liver and gonad putrescine was detected in the highest amounts, followed by sperrnidine and spermine. Immediately after death glycogen level was about 0.5 % and fairly large amounts of glucose and glucose-6-phosphate, and large amounts of lactic acid were detected.

Abstract:A strategy to improve aquaculture mollusks in genetics, which involve the theory, method, material and application system, is very important for the sustainable development of the marine molluscan breeding and industry. Selection and hybridization as the traditional way have proved effective in the genetic improvement of mariculture mollusks. The growth had increased significantly by selective breeding in oysters as well as the resisitance to MSX and QX disease. A frame chart of genetic improvement of mollusks had been derived from the breeding application of abalone and scallop. The systematic breeding with selection and hybridization has a substantial progress based on the family establishment in Haliotis discus hannai, H. diversicolor, Argopecten irradians, Chlamysfarreri and Pinctada martensii. The first self-fertilized family of bay scallop had been established in the 1999 and then a series of family lines with different traits have been succeed and formed the basic element of genetic breeding. The hybridization of Pacific abalone between diffeent populations with a large genetic distance has showed a remarkable traits. The hybrid of Pacific abalone has applied to improve the traits of growth and resistance in the aquaculture and 98 % seed used in the farming is hybrid. The hybridization among populations has used in other mariculture mollusks such as zhikong scallop, bay scallop, pearl oyster and small abalone. Hybridization among different populations and systematic and massive selection are the dominant approaches in the genetic improvement of mollusks. So far in China the material system for molluscan genetics and breeding is more considerable as well as the basic theory of beritabilily, hetemsis, inbreeding depression, genetic-environment interaction for the genetic improvement. The different lines have been produced by self-fertifization, inbreeding and crossing and some serf-fertilized lines of bay scallop have been bred to F4 successively. The color traits heritable are useful as the marker of selective breeding. It is necessary to deal with the molecular marker-assisted selection and design breeding. The molluscan mortality happened in aquaculture was mainly resulted from the physiological depression under the interaction of genetics and environment. So the phenomena of minimization and abnormal mortality in the mariculture mollusks should be described as ＂trait depression＂.

Abstract:This article reviewed the advance in aquatic animal pigmentation, including theory and practice of pigmentation. Color plays a very important role in determining quality and price of cultured fish, shrimp and other aquatic animals. The beautiful color of red, orange, yellow is due to a group of pigments named carotenoids, which could not be obtained from de novo synthesis by these animals, but directly from diets. Astaxanthin and lutein are main pigments existing in aquatic animals, so adding such carotenoids in artificial diets is an important way to improve the color of skin and flesh. On the basis of where astaxanthin is biosynthesized, aquatic animals could be divided into 3 types, red carp type, sea bream type and prawn type. For prawn type, including prawn, crab, lobster and other crustaceans in which astaxanthin is the main carotenoid, color could be improved by feeding β - carotene, astaxanthin, canthaxanthin, zeaxanthin and lutein, but astaxanthin and canthaxanthin are more effective. For red carp type, including red carp, goldfish, fancy red carp and most freshwater fishes, astaxanthin, canthaxanthin, zeaxanthin and lutein could be fed, but only astaxanthin, canthaxanthin could be fed to the third type including sea bream and salmonids, and the adding level of these pigments is about 50 - 100 mg? kg^- 1. There are 2 kinds of pigments could be used in aquatic feeds, carotenoids additives and natural feedstuffs rich in carotenoids, such as green alga, yeast Phaffia rhodozyma, and shrimp waste. Many factors affect the pigmentation of aquatic animals, which includes the species, size and physiological situation of animals, diets composition, source and kinds of pigments. Other factors such as feeding rate, water temperature, and brightness also play some roles in color formation of aquatic animals. So, attention must be paid to satisfy pigmentation for aquatic animals. Compared with Western countries, the research and use of aquatic animals pigmentation in China are late and superficial, but develop rapidly in recent years. In the future, more attention should be paid to metabolism, regulation and affecting factors of pigmentation based on characteristics of cultured conditions, species and feedstuffs, to promote pigmentation theory and practice of aquatic animals in China.