Abstract:In order to study the potential functions of DEAD-box family genes p68 and p110 in germ cell proliferation and diffemtiation, using in situ hybridization on tissue sections with DIG labeled antisense RNA probe, we detected the location of goldfish （Carassius auratus） DEAD-box family genes p68N and p110 RNA during gametogenesis. The results are as follows： during goldfish oogenesis, the expression of p68 RNA was observed in oocytes at all stages, and its expression was higher in stage Ⅰ , Ⅱ oocytes than in stage Ⅲ, Ⅳ oocytes. The expression of p110 RNA could not be found in stage Ⅰ oocytes and strong signals could be detected in stage Ⅱ oocytes, but the signals became much weaker in stage Ⅲ, Ⅳ oocytes. During goldfish spermatogenesis, the expression of p68 RNA could only be detected in spermatogonia and primary spermatocytes. The expression of p110 RNA was visible throughout spermatogenesis, and its expression was much higher in spermatogonia and primary spermatocytes than in spermatids. Based on the active expression of p68 and p110 during goldfish gametogenesis, we speculated that they may play potentially important roles in germ cell development of both sexes.

Abstract:The enzyme aromatase P-450（P450arom） catalyzes the conversion of androgen to oestrogen. A cDNA encoding P450arom was derived from yellow catfish （Pelteobagrus fulvidraco） brain, using RT-PCR and RACE. The cDNA was 2080 bp with 25 bp 5′ UTR, 555 bp 3′ UTR（ excluding poly（A） ） and 1500 bp ORF, which encodes 500 amino acids and has a predicted mol wt of,56 kDa. The yellow catfish brain-derived P450arom shares above 70% sequence identity with brain-derived aromatases of other fish species, but only about 60% with ovarian aromatases of other fishes, about 50% with human placenta and chicken ovarian aromatases. But the percentage of identity/similarity was higher in the regions of high homology, including the Ⅰ-helix, an aromatase-specific conserved region Ⅱ, and the heme-binding region Ⅲ, their homology being 823% - 96%, 78% - 86% and 85% - 100% respectively. Phylogenetic analysis of the P4.50arom gene family indicated the yellow catfish brain-derived P450arom was clustered with other fishes brain-derived P450arom, and is the closest with channel catfish. This result is consistent with the result of traditional classification. The fluorescent real time quantity RT-PCR analysis revealed HP450arom B is expressed in fore-brain , hypothermia, pituitary, ovary and testis, but is high in brain and low in gonad. There is no expression in liver. There is no significant difference between male fish and female fish brain.

Abstract:QM homologs, associated with tumor suppression, cell growth, differentiation, development and apoptosis, were isolated from human and many other organisms. However, QM derived from fish was not reported. Through integrated analysis of public database such as EST, TIGR Gene Index in silico, a full-length eDNA encoding QM homologue of human QM protein was identified from Danio rerio, which is 769 bp length and has a putative protein of 215 amino acids with a predicted mol. wt. of 24.6 kD and isoelectric point of 10.6. It was found that Danio rerio QM amino acid sequence includes 1 Ribosomal protein L10e signature, 2 Amidation sites, 1 Tyrosine sulfation site, 1 N-myristoylation site and 1 Protein kinase C phosphorylation site by scanning PROSITE motifs. The Danio rerio QM shares an 66% - 92% amino acid sequence identical to other proteins of the QM family, including human etc, respectively. Study showed that Danio rerio QM gene expressed in all Danio rerio embryo and adult tissues by digital differential display based on UinGene. The experiment provided us with a feasible bioinformatics method for cloning new functional genes, thereby preparing for further research on fish QM gene function.

Abstract:Traditional morphological data and truss network data were combined to conduct a multivariate analysis to study the morphological variations and phylogenesis of four strains in red common carp （ Cyprinus carpio ） ： C. c. vat. color, C. c. vat. singguonensis, C. c. vat. wananensis and C. c. vat. wuyuanensis. The results indicate that： （ 1 ） In the aspect of meristic characters, there were no significant differences（ P 〉 0.05） among the four strains; （2） In the aspect of traditional measurable characters plus truss network characters, there were significant differences（ P 〈 0.05 ） among the four strains. Cluster analysis showed that C. c. var. wuyuanenis was separated from the other three strains which are close to one another; discriminate functional analysis based on 28 ratio variables showed that there were highly significant differences among the four strains（ P 〈 0.01 ）; discriminate functional analysis with 8 selected morphological ratio variables gave a synthetic discriminating accuracy of 92% ; principal component analysis indicated that morphological differences among the four strains were mostly due to variations in the frontal part of the body. （3） Using various multivariate analysis techniques to analyze the combination of traditional morphological data and truss network data greatly enhances the study capacity for morphological variations and phylogenesis among populations or strains under a species of fish.

Abstract:The applicability of microsatellite primers from Gyprinus carpio to Monopterus albus population was studied in the present paper. The results showed that 11 of the 31 pairs of microsatellite primers from Cyprinus carpio could amplify Monogpterus albus DNA and produce special allele patterns. The allele numbers for each primer ranged 3 to 13, and a mean of 5.6 alleles were found for each locus, which indicated a higher polymorphism. P1 was the most perfect primer among all these 11 pairs, which could distinguish the 3 Monopterus albus populations collected from Hunan, Guangdong （China） and Bengal. The results of the polymorphisms of genetic DNA of Monopterus albus populations from the 3 different locations showed that the average similarity of the 3 Monopterus albus populations from Hunan, Guangdong and Bengal was 95.5 %, 95.8 % and 93.5 %, respectively, and the average variability was 0. 045,0. 042 and 0.063, respectively. The average similarity and variability between every two of the three populations were： 91.0 % and 0. 045 between Hunan and Guangdong populations, respectively, 55.7 % and 0. 443 between Hunan and Bengal populations, respectively, and 58.6 % and 0. 414 between Guangdong and Bengal populations, respectively. By summarizing all the data from microsatellite analysis, morphological characteristics and geographic distribution, the authors could deduce that the Monopterus albus populations from Hunan and from Guangdong were the same species, and the population from Bengal belongs to another species.

Abstract:Skin, gill and intestinal epithelial cells were developed using primary cultures of mucosal cells （isolated from healthy Nile tilapia） to study the adhesion of Aeromonas hydrophila to fish epithelial cells and the effects of Cu beating montmorillonite （Cu-MMT） on the adhesion of bacteria and on cell membrane injury due to Aeromonas hydrophila. The three primary-culture cells are susceptible to Aeromonas hydrophila attachment, with the greatest binding affinity found in gills, and to a lesser extent, in skin and intestine epithelial cells. Cu-MMT significantly inhibited （P 〈 0. 05） adhesion of bacteria to skin, gill and intestinal epithelial cells. The cell membrane was injured due to Aeromonas hydrophila. The activity of cytosolic free calcium concentration and membranous phospholipase A2 were increased （ P 〈 0, 05 ） significantly. Cu-MMT can significantly reduced （ P 〈 0.05 ） cell membrane injury caused by the adhesion of Aeromonas hydrophila. Our study shows that Cu-MMT showed a strong ability to inhibition adhesion of pathogenic strains to fish epithelial cell and open the possibility of applying Cu-MMT in aquaculture.

Abstract:A proteinase, which has important work on turbot digestive, was purified from turbot （ Scophthalmus maximus L. ） and its major physical and chemical characteristics were studied and reported in this article. The intestine proteinase extraction was prepared through homogenate and centrifugation by Tris-HCl buffer at low temperature. The supematant was purified through ammonium sulfate grading precipitation further and the active component was dialyzed and concentrated. Then the condensed proteinase was purified by means of DEAE-Sepharose Fast Flow anion-exchange chromatography with an elution of a linear gradient of 5 mmol?L^-1 Tris-HCl buffer （pH 8.5） containing 1.0 mol?L^-1 NaCl. At last, the. pure enzyme was obtained through Sephadex G-100 chromatography with an elution of 5mmol?L^-1 Tris-HCl buffer （pH 8.5）. The purity of the purified intestine proteinase was confirmed by the presence of a single band on SDS-PAGE. The relative molecular mass of this enzyme was determined to be about 58 kD. By using casein as substrate to measure proteinase activity, the characterization of turbot intestine proteinase was made. The enzyme is stable at pH 6.0 - 11.0 and temperature below 30℃. When the temperature rose, there was a rapid decline of its stability. The enzyme showed maximum activity at pH 9.0 and 50℃. When the temperature declined, the optimum pH of enzyme showed a trend of moving to alkaline. And when the action time prolonged, the optimum temperature of enzyme showed a fiend to decline. Furthermore, the enzyme is activated by Mn^2＋ and inactivated by Cu^2＋ ,Zn^2＋,Ag^＋,Fe^3＋ . In further studies, it was inhibited by SH-enzyme inhibitors such as p-Hydroxymercuribenzoate （ PCMB ） and N-bromosuccinimide （ NBS ） remarkably, and partially inhibited by tosyl-lysine chloromethyl ketone （TLCK）. Using casein as the substlate, the Km value of enzyme is 2.92g?L^-1 at pH 9.0,50℃. The result showed the enzyme seemed to be a SH-enzyme.

Abstract:The activities of ACP and ALP in hepatopancreas and gonads of immature, precocious and normally mature Eriocheir sinensis were assayed at 520nm wave length. Firstly, the activities of ACP and ALP in hepatopancreas were significantly higher than those in gonads. Secondly, the activities of ACP in hepatopancreas of precocious crabs were significantly higher than those of immature crabs, but lower than those of normally mature crabs, and no sexual difference existed. However, the activities of ACP in ovaries of precocious and normally mature female crabs were correspondingly lower than those in testes of precocious and normally mature male crabs. There was no difference between precocious and normally mature crabs. Thirdly, the activities of ALP in hepatopancreas of precocious female crabs were significantly higher than those of immature and normally mature female crabs, but at the same level as three groups of male crabs. However, there was no significantly difference between the activities of ALP in gonads of precocious and normally mature crabs. Therefore, the following could be concluded： （1）mobilization or synthesis of those nutrients required by gonads was related to ACP in hepatopancreas; （2）onset of precocity was related to significant elevation of activities of ACP and ALP.

Abstract:The morphology of an isolate of parasitic ciliate Cryptocaryon irritans obtained from cage-cultured snubnose pompano （Trachinotus blochii）from Huidong, Guangdong Province in China, was examined by observation of scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The strains were maintained in experimentally infecting snubnose pompano from which the sample used for ultiastructural observation was collected. The general structural organization of the pellicles resembles that of the freshwater holotrich lchthyophthirius multifiliis, consisting of three membranes： outer limiting membrane, the outer alveolar membrane and the inner alveolar membrane. The pellicular alveoli are characterized by the accumulation of election dense material in the trophont, tomite and theront, this material being lost in the newly-encysted tomont. The theront, tomite and tiophont possess a complex oral apparatus, being composed of cytopharynx, oral rib, dikinetids and nematodesmata, without an organelle of Lieberkuhn which is considered as a synapomorphy of the suborder Ophryoglenina. The monokinetid somatic cilia appear in rows longitudinally on the theronts, tomites and trophonts, but being lost at early stage of tomonts. There are mitochondria, Golgi apparatus and lipid droplets in the cytoplasma of all stages of parasite, and mucocysts, contractile vacuoles and endosymbiotic bacteria in theronts and trophonts. The size, shape and distribution of mucocysts in C. irritans are different from thoseof I. multifiliis. The present study suggests that the taxonomic affinities of C. irritates should lie with prostome ciliates by analysis of its different morphological characteristics from I. multifiliis.

Abstract:Ultrastructure of mature spermatozoon of Purpura clavigera K?ster was observed by transmission electron microscopy. The mature spermatozoon contains two parts： head and tail. The head comprised an acrosome and a nucleus. The slim-cone shaped acrosome is about 2μm in length. The content in the acrosome is homogeneous and highly electron-densed. The morphology of subacrosomal space which is filled with highly electron-densed materials is similar to the shape of acrosome. The cylinder nucleus is about 16 μm in length. The content of the nucleus is highly densed. The nucleus is homogeneous. The endonuclear channel extends to the front part of nucleus from caudal nucleus. The inner diameter of the endonuclear channel is about 0.2 μm. The basal body is formed by a single centriole which is located at the apex of endonuclear channel. The “9 ＋ 2” arrangement of axoneme emitting from basal body run through the whole sperm. The tail is composed of mid-piece, principal piece and end piece. The chondriosomal mantle which is formed by filar mitochondria enwraps the “9＋2” arrangement in the middle piece. The thickness of every mitochondrial gyration is about 0.1μm . The distance between gyration is equidistant. No chondriosomal mantle exists in the principal piece, only glycogen particle mantle surrounds axoneme. In the end piece, only plasma membrane surrounds the axoneme. The similarities and differences of the sperm ultruastructure between Purpura clavigera K?ster and other Prosobranchia including Archaeogastropoda, Mesogastropoda and Neogastropoda are discussed. The evolving trend of Prosobranchia sperm can be seen obviously by comparing the structure. The sperm structure of Prosobranchia changes from “primitive type” which was found in Archaeogastropoda to “modified type”, the latter were found in Mesogastropoda and Neogastropoda. The head of Archaeogastropoda sperm that undergoes external fertilization tapers. The rear part of the nucleus has a posterior nuclear pocket. The proximal and distal centrioles are located in posterior nuclear pocket. The distal contrioles emits axoneme and finally forms the tail. The simple tail contains a short mid-piece and a slim end piece. Several mitochondria enwrap centriole in middle piece. In the end piece, only plasma membrane surrounds the axoneme. The head of sperm in Mesogastropoda and Neogastropoda animals which undergoes intemal fertilization is slim. The tail is composed of middle piece, principal piece and end piece. The chondriosomal mantle which is prolonged and originated from mitochondriasurrounds the axoneme. In the principal piece, the “9＋2” axoneme was surrounded by glycogen particles. The ultrastructure of the end piece is the same as Archaeogastropoda animals. Chondriosomal mantle is formed to cumulate more energy and the glycogen particle mantle can supply more energy. The formation of chondriosomal mantle and glycogen particle mantle in the sperm tail meets the energy requirement for the intemal fertilization, and it also shows us an important morphological feature during the sperm evolution. Purpura clavigera sperm ranks higher evolutionary status in Prosobranchia than other species. The following aspects should be considered when we pursue Prosobranchia species evolution： The existence or not of acrosome, the fine feature of acrosome, the shape and the length of nucleus, the number, morphology and the arrangement of mitochondria in the mid-piece, and the existence or not of glycogen particle mantle. The comparative study on representative species sperm structure in different order, family, genus of Prosobranchia can help us in revealing the evolutionary trend of Prosobranchia, and also in analysing the evolutionary relationship of different order, family, genus and species.

Abstract:Individuals of Portunus trituberculatus were collected from Shipu Port, Xiangshan, Zhejiang Province from March 2033 to June 2004. The chromosomal number and karyotype of the swimming crab were studied by the tissue slice techniques applied to the mature oocytes and the air-drying method applied to the testes, embryos and zoeae. The spread plates were examined and the chromosomes at the mitotic or meiotic metaphase were photographed under an Olympus microscope. The chromosomes pairing were processed according to the relative lengths and the centromeric indexes. The chromosome pairs was classified following the method of Levan et al （ 1964）. The results indicate that the testes are the best materials to be used in chromosome count and the egg-zoeae are the best materials to be used in karyotype analysis. The chromosomal numbers for P. trituberculatus are 2n = 106, n = 53. All chromosomes （2n= 06） were matched in 53 pairs. They were divided into 3 groups. Group Ⅰ contains 20 pairs （ lst- 20th） that are metacentric chromosomes（m）. Group Ⅱ has only 3 pairs （21st - 23rd） of submetacentric chromosomes（ sin）. And group Ⅲ includes 30 pairs （24th - 53rd） which are telocentric chromosomes（t）. Therefore, the karyotype formula of P. trituberculatus is 2n = 106 = 40m ＋ 6sm ＋ 60t, NF= 152. No sex-chromosome of heteromorphism was observed.

Abstract:Lectin was purified from Apotichopus japonicus Selenka by extraction with PBS, followed by 20% - 75% ammonium sulfate fractionation and molecular sieve chromatography on the Sephadex G-200 . The Lectin had a molecular weight of 85 652 Da on Sephadex G-200 and contained saccharied of 20.9%. The lectin was nonspecific in agglutination for any type of human erythrocytes, and the hemagglutinating activity for human（ A） was the highest, the agglutination for chicken was the highest, among erythrocytes of humans（ A, B, AB, O）, rabbits, mouse and common carp. The hem,agglutinating activity for rabbit could not be inhibited by D-galactose, glucose, sucrose, mannan, gamma-globulin（human）, but inhibited by bovine-thyroglobulin. The minimum inhibitory concentration was 1.55 mg?mL^-1. The hemagglutinating activity was not inhibited by treatment with EDTA and Ca^2＋ ,Mg^2＋ . This lectin had the maximum hemagglutinating activity at pH 4.4 - 7.5, with activity at pH 4.0 - 10.14. The lectin still showed aggllutinating activity after being treated with 90℃ for 30 minutes, indicating that it had a high heat resistance.

Abstract:Growth performance, oxygen consumption rate and biochemical composition of young sea cucumbers were studied at constant and fluctuating temperatures. Groups of young sea cucumber, Aposticchopus japonicus, were reared at fluctuating temperatures of 15?2, 18?2 , 21?2℃ and others were reared at constant temperatures of 12, 15, 18, 21 and 24℃ as controls. Specific growth rates （SGR） were measured under different treatments. Results showed that temperature had significant effects on the growth of sea cucumber. At constant temperatures, growth of young sea cucumbers increased with the increasing of temperature from 12 to 18℃. The subsequent increase of temperature led to the comparative deceleration of the growth rate. Therefore, the appropriate temperature for the growth of sea cucumber was from 12 ℃ to 21℃, and the thermal optimum for growth was about 18℃. Within the ecological tolerance range for the species, the growth rate in fluctuating temperature groups increased compared to the growth rate in the control groups with a constant temperature equal to the average oscillating one. SGR significantly decreased when the temperature fluctuating occured around 21℃. Analysis of covariance （ANCOVA） was used to test the relationship between temperature and body composition of young sea cucumber. The effects of different temperature treatments on body contents of crude protein, crude lipid and energy of sea cucumber were significant. The contents of crude lipid of young sea cucumber reared at fluctuating temperatures decreased compared to those reared at constant temperatures. Among three constant temperature groups, oxygen consumption rates of sea cucumbers increased along with the increasing of temperature treatments. However, there were no significant differences among oxygen consumption rates of sea cucumbers under three constant temperature treatments （ P 〉 0.05 ）. In three fluctuating temperature groups, oxygen consumption rates also increased along with the increasing of temperature treatments. The oxygen consumption rate of sea cucumber in 21＋2℃ was significantly higher than that in 15?20℃（ P 〈 0.05）. Temperature fluctuation enhanced the oxygen consumption of sea cucumbers in the 18?20℃ and 21?2℃ when compared to rates of animals subjected to constant temperattLre. However, the differences of oxygen consumption rates between fluctuating temperature treatments and constant temperattLre treatlnents were not significant （ P 〉 0.05）. Temperature in the sea cucumber culttLre pond can be controlled in the range of 15-18℃, and with a fluctuating amplitude of ＋2℃. By this kind of temperature control mode, growth of young sea cucumber will he accelerated.

Abstract:Differentially expressed cDNAs subtracted female from male gametophytes of Laminaria japonica were obtained by suppression subtractive hybridization （SSH）. The differentially expressed cDNAs from the male gametophytes were ligated into the pGEM-T vector and the latter was consequentially transformed into Escherichia coli JM109 competent cells. The subtracted cDNA libraries of male gametophytes were constructed. One hundred randomly selected clones were amplified by PCR using T7 and SP6 primers for primary screening. The length of inserted fragments assayed by PCR amplification was mostly from 200 to 1000 base pairs. Ten clones obtained after dot-blot Southem hybridization were sequenced and analyzed for homology comparison using BLAST. Seven of the ten clones showed no sequence homology in the GenBank database, suggesting that they or at least some of them with longer base pairs might represent novel gene sequences. The other three clones shared 88% and 98% sequence homologies with understood Fop and Lhcfs genes, respectively.

Abstract:The temperate bass,Lateolabrax maculatus, collected by a seine net from the mouth of Hangzhou estuary, China, and Ariake Bay and Shimanto estuary of Japan were described and compared based on morphological characteristics, the number of vertebrae, dorsal and anal pterygiophores in postflexion larval and juvenile stage. The results were revealed that specimens from the mouth of Hangzhou estuary and Ariake Bay were very similar, not only on morphological characteristics but also on internal skeleton above. However both differed markedly from the specimens of Shimanto estuary in the pattern of pigmentations, proportion of the snout and body depth to standard length, the mean number of vertebrae and dorsal pterygiophores. These morphological characteristics proved the similarity of temperate bass from the mouth of Hangzhou estuary and Ariake Bay. There are some obvious morphological differences between the Chinese and Japanese temperate bass either the early developmental stages or adult. These morphological differences suggested that Chinese temperate bass should be distinct species. The scientific name of Chinese temperate bass should be changed to Lateolabrax maculatus （McClellan）.

Abstract:n the paper, the quantitative variation and distribution of microorganism population in shellfish culture shoal of south bank in Hangzhou Bay was studied, The samples were collected from 3 different sites in Hangzhou Bay. The results indicate that heterotrophic bacteria variation is from 1.62?10^3-6.62?10^5cfu?g^-1, mean 4.28?10^4cfu?g^-1, and there is a low quantity in spring and summer, rising in October and reaching the peak in November in the sample sites. About bacteria populations, dominant species is gram-positive bacteria, which is characterized with an obvious origin from land. Denitrifying bacteria, ammonifying bacteria and sulfate-reduction bacteria all were found in these sites and maintain a high level although there was a difference in quantity between bottom and surface layers in the shoal, surface layer being higher than bottom.

Abstract:In China, studies on the artificial inducement of reproduction in eel （Anguilla japonica） have been carried out since 1973. The silver migrated eel has been previously used as material fish for experiments on artificial inducement. Since the acquisition of wild silver eel has become difficult in recent years, the cultivated eels have been used as our experiment animals. Although the study on the process of the development of the embryo from the wild eel by artificial induction has been reported, the development of the embryo and larva from cultivatedeel has not been published. In this paper, the characters of embryos and early larvae of cultivated eel by artificial induction in every stage were observed and photographs were taken, the whole process of embryonic development lasted for about 49 h at 20.5℃, 39 h at 22.5℃ and 34 h at 24.5℃. The fertilized eggs of the fish are spherical and orange-yellowish, the diameter of swollen egg is 1.0 - 1.2 mm in water. Fertilized eggs were kept in seawater at 22.5 ℃. The first cleavage occurred at 1 h, epiboly began at 11 h, the embryonic body was formed at 28 h and hatching occurred at 39 h after insemination. Newly hatched larva were approximately 3.1 - 3.7 mm （total length） and similar to those of wild eel in terms of external features.

Abstract:To investigate the feasibility of applying plant eco-filtration method in recirculating aquaculture systems, four 3.0 m?0.5 m?0.05 m （L ? W ? H） plant filters were used to provide 4 replicates for treatment of wastewater from a Colossoma brachypomum intensive system. 0.8m^2 NFT （nutrient film technology） Lolium perenne was planted on each filter. Wastewater was loaded at a rate of 25.4 liter per week for an investigation of 40 day. After a recirculating irrigation of 7 days, the plant filer removed 96.1% of nitrate nitrogen, 86.2% of total nitrogen, 90.5% of total phosphorus, and 88.7% of COD, respectively, pH was raised from 6.4 to 8.4 and only 29.7 % of water was used. All parameters conformed to qualifications of China water quality standard for fisheries except unionized ammonia nitrogen as a result of high pH. The grass height increased at a rate of 2.3 mm?d^-1, significantly slower than that irrigated with commercial nutrient solution with a growth of 13.2mm?d^-1. Total ammonia nitrogen and nitrate nitrogen concentration of the fresh grass leaves were 107.9 and 42.5μg?g^-1, respectively. At the end of this experiment, 582.9 g?m^-2 fresh grass was produced and then was turned over to 102.5 g?m^-2 dry mass with a dry weight to fresh weight ratio of 0.176. It can be concluded that the plant filter is an environment-friendly way to solve accumulation of N, P, and COD, and descent of pH in recirculating aquaculture systems. With a view to healthy growth of grass, it＇s recommended that grass in plant filters should be periodically returned to breeding systems for a certain term irrigation of commercial nutrient solutions.

Abstract:The functional characteristics of native fish protein can be changed under conditions of extrusion cooking, depending upon the operational variables used. A Clextral BC-45 laboratory-scale twin-screw extruder was used together with response surface methodology to study the effect of process parameters on functional properties of textured fish protein, Parameters examined were： barrel temperature in the last zone, screw speed, teed moisture; each at 5 levels. Water holding capacity and texture profile assessments of the resultant extmdates were made, Results had shown that all of three operational variables did not affect wet extrusion cooking in the same way. Polynomial regression equations of process variables with two functional properties were obtained with R^2 = 1.000, and R^2 = 0.933, respectively. Both of regression equations are hightly credible.

Abstract:Fishing-ground analysis and fishing condition forecasting are important research focuses of fisheries oceanography in recent decades. Theoretic basis of fishing-ground analysis and fishing condition analysis are summarized firstly, then the ways of data acquired, technologies for fishery mapping and visualization analysis, as well as new analysis and predicting methods are descrihed, such as spatial analysis models and geostatistics, artificial intelligence, rough set, fuzzy logic, Bayesian probability forecasting, numerical simulation and so on.

Abstract:Branchiostegus is a demersl fish in warm water. It is documented that there are four species of the fish in China water areas. Here are reported the biological characteristics and stock situation of Branchiostegus japonious and Branchiostegus albus mixcommunity which were captured by deep water drift net in the west of 27?00′ - 34?00′N, 128?00′E in the period ranging from Aug. 1998 to June 2004. The captured fish length was 100 - 390 mm, with the average length being 223.9 mm. Individual weight was 30 - 1470 g, with the average weight being 231.5 g. The captured fish was 1 - 9 yearling and predominant group was 1 - 3 yearling. The length was a power function of the weight. The average length and weight of male fish were greater than the female, while the female showed a little bit fatter. In the natural community, the ratio of female to male was approximately 1 ： 1.2. There were spawning areas, and its period was from April through to Aug, The Branchiostegus is eury-carnivore. It would not stop taking food when breeding. The habitat areas of the main Branchiostegusjaponious were in the east of 126?00′E, while B. a/bus in the west of 124?00′E, both communities were found in 124?00′ - 126?00′E. The landing of Branchiostegus was about 30% of its total production, much more than other species. For the time being, Branchiostegus stock has not been found declining apparently. However, as compared with earlier time, its production rate in its total landing has declined a lot. Hence, it is imperative to exploit it wisely to realize sustainable development.

Abstract:Degenerate primers were designed according to the conserved sequences of NADH dehydrogenase subunit 2 （ND2） gene in mitochondrial tRNAMet and tRNAvrp gene respectively, and the complete sequence of the ND2 gene of Eriocheir japonica was determined. The results indicated that the length of ND2 gene of Eriocheir japonica was 1009 bp. The A, T, G, C contents of the gene were 28.54% （288 bp）, 44.20% （446 bp）, 8.23% （83 bp）, and 19.03% （ 192 bp） respectively; and the sequence was AT rich and biased. The start and stop codons were ATC and A respectively. The homology analysis of nucleotide sequence showed that the similarities in NEE gene between Eriocheir japonica and other crustacean were comparatively low, which suggested that ND2 gene could be effective molecular marker for further study on phylogeny of Eriocheir species.

Abstract:The metallothionein （MT） concentration in hepatopancreas of Litopenaeus vannamei changed significantly with the increasing of metal ions concentration and prolongation of exposure time （ P 〈 0.05 ）, whereas that in the control groups had no marked changes （ P 〉 0.05 ）. Exposed to three heavy metal ions, the MT concentration in hepatopancreas changed very significantly in 6 h （P〈0.01）. The MTconcentration inducted by Cu^2＋（0.1, 0.2, 0.5, 1 mg?L^-1）, Zn^2＋（1, 2, 5 mg?L^-1） and Cd^2＋ （0.05, 0.1 mg?L^-1 ） increased in 96 h with time and changed stably after 48 h. In addition, the MT concentration inducted by Zn^2＋ （ 10 mg?L^-1 ） and Cd^2＋ （0.25, 0.5 mg?L^-1） was up to max. at 48 h, began to decrease with time passing by, and still higher than that in the control groups. Meanwhile the inductive ratio of three heavy metal ions on metallothionein concentration were Cd^2＋ 〉Cu^2＋ 〉Zn^2＋ in experimental time.

Abstract:The water treatment effect of a protein skimmer with different ozone concentrations for recirculation system of industrial fish farming was studied in this paper. Foam separation principle and ammonia nitrogen removing theory of the protein skimmer was described. A protein skimmer with a discharge of 50 m^3?h^-1 was designed. The skimmer was used in a recirculation system, and relative water quality parameters：protein, ammonia nitrogen, nitrite, nitrate, organic nitrogen, suspended solid, dissolved oxygen, were tested. The results showed that the egesta of the fish reared and the feedstuff residual could be removed efficiently. The removal efficiency of ammonia nitrogen and protein in the recirculation system was very high by entering ozone into the protein skimmer. The removal rate of protein, ammonia nitrogen, nitrite, nitrate, organic nitrogen, suspended solid were various along with the different ozone concentrations. And the dissolved oxygen was greatly increased.

Abstract:In this paper, six specimens made by four kinds of fiber materials used in sea cage were selected, the percentage of elongation of them were measured by two methods. The two forms regression equation of percentage of elongation and relatively load rate were established, one of them expressed the power function, and another expressed the linear function. The constant load elongation of new ropes and simulated loaded ropes, and the method to estimate at breaking elongation were brought forward. The attenuation of extensibility of rope during load and unload test according to 50% rated breaking load of it was discussed. The result of test and study on the elongation performance of the fiber ropes show that it may be the reference for the design, to calculate the length of the ropes used in the sea cage as traction cordage or anchor hawser.