Abstract:The ultrastructure of spermatogenesis and spermatozoon of Coelomactra antiquata was observed with transmission electron microscope. Detailed observations and descriptions of morphological and structural changes of cells as well as transformat ion of cell organells were made submicroscopically from spermatogonia to spermatozoa. The spermat id differentiat ion can be divided into six stages. During spermatid differentiation, the main changes are as follow: elongation of nucleus, condensation of chromatin( in granular pattern) , acrosome format ion, development and fusion of mitochondria centriole shifting, and flagellar formation cytoplasmic sloughing. Mature sperms are of typical primitive type, consisting of three regions: head, middle piece and tail. The acrosome is conical. Acrosomal materials w ith a lampshade-shaped structure lie round its base. The subacrosome space is conical w ith materials of low density. The nucleus is ellipsoidal. Four large ellipsoidal mitochondria and two centrioles make up the middle piece. The flagellum is a standard / 9+ 20 microtubular structure.

Abstract:This paper deals with the morphologic and histological studies on the ovary of Parapenaeopsis hardwickii. According to its morphologic and histological characters, the development of the ovary was divided into six phases as follows: forming phase, small developing phase, great developing preliminary phase, great developing anaphase, ripe phase and recovery phase. The period of the ovary development in Zhejiang sea area is one year. The female spawns from May to September, and the peak is June to July. The type of spawn is several times.

Abstract:The gonadosomatic indexes (GSI) of the triploid crucian carp , produced by crossing the alloteraploid hybrids ( ♂) of red crucian carp ( Carassius auratus red var. ) ×common carp ( Cyprinus carpio L . ) with the diploid Japanese crucian carp ( ♀)( Carassius auratus cuvieri T. et S. ) , and the diploid Japanese crucian carp were compared. The indexes of the ovaries , testes and the fat tissue“gonad”found in the triploid crucian carp were respectively lower than those of the ovaries , testes and the average value of the ovaries and testes found in the Japanese crucian carp. The indexes of the ovaries and the testes in the Japanese crucian carp were respectively 2.85 and 1.94 times of the indexes of the ovaries and the testes in the triploid crucian carp. The index of the average value of the ovaries and testes in the Japanese crucian carp was 5. 60 times of that of the fat tissue found in the triploid crucian carp. In the triploid crucian carp , the fish with the fat tissue“gonad”grew faster than the others. The females grew faster than the males. No germ cells in the fat tissue “gonad ”were observed , suggesting that the development of the germ cells was completely repressed. The repressed degree of the ovaries in the female triploids was higher than that of the testes in the male triploids due to the absence of the yolk in the oogonium2like cells that occupy most space of the ovaries. Considering the sterility and the fast growth rate , the triploid fish with the fat tissue“gonad”were the best ones .

Abstract:The present paper deals with the early development of Tor brevifilis brevifilis. The development characters of embryos and larvae in every stage have been carefully observed for three times. The experiment obtained the sum of heat and the product of effective temperature by time in all stages of embryonic development. The growth digits in 105 days during larval development were measured. The fertilized eggs are sticky , their diameters are 1. 7～1.9mm and 2.5～2. 7mm after being expanded in water. While the water temperature is 20. 5～23. 0 ℃,thewholeprocessofembryonicdevelopmentlastedfor 71 hoursand 7minutes. Themeanlength of newly hatched larva is 6. 6mm. After 65 to 72 days , the development of larvae has nearly completed. The desired lowest temperature during embryonic development and several obvious characters in its total early development have been discussed.

Abstract:Employing PCR method , the cloned grass carp IGF2 Ⅰgene was modified to be a mature IGF2I peptide gene and then subcloned into fusion expression vector pGEX24T21 to construct expression vector pGEX2IGF. Restriction endonuclease analysis and sequencing confirmed the corrected construction. The vector was transformed into Escherichia coli BL21 cell which can be induced by IPTG to produce a special protein of 34kD in molecular weight. The special protein can be mainly in form of soluble protein or inclusion body when induced at 30 and 37 ℃ respectively. The cells induced at 30 ℃ were digested by lysozmye and disrupted by sonication. After being centrifuged the supernatant was purified by glutathione sepharose column. GST2IGF fusion protein could be absorbed specifically on this column. The high purified protein was used as antigen to immune rabbits directly and high quality antiserum was obtained , which showed that the fusion protein possesses good immunogenicity.

Abstract:The requirements and optimum ratio of calcium to phosphorus in the compound feed of grass carp ( Ctenopharyngodon idellus) were studied. Results were analysed based on the two biological indexes of weight gain,feedconversionratioandfeedefficiency. Resultsshowthecalciumrequirementis 0.473 %-0.788 %, Phosphorus requirement is 1. 419 % -1. 577 % , total requirement is 2. 1 % -2. 7 %. The optimum ratio of calcium to phosphorus changed with the levels in feed. When calcium and phosphorus levels were lower , but total level was different , the optimum ratio of calcium to phosphorus is 1∶3. When calcium and phosphorus levels were higher , but total level was same , the optimum ratio of calcium to phosphorus is 1∶2. When the phosphorus value is below 2 in the ratio,higher total level of calcium and phosphorus can decrease the stress of grass carp because of imbalance of calcium and phosphorus. When the ratio of calcium to phosphorus is not 1∶2, or 1∶3, higher or lower total levels of calcium and phosphorus can affect the growth and feed conversion ratio of grass carp .

Abstract:The experiments were conducted to investigate the effect of ice fresh trash fish , formulated feed and mixed feed (30 % ice fresh trash fish + 70 % formulated feed) on the nutrient components of Chinese soft2shelled turtle Trionyx sinensis. Raised for five months , six turtles per group (about 600g , male) were selected to check nutrient components. The results showed that no significant differences were found between them in percentage of dissected fat , content of crude protein and fatty acids ( P > 0. 05) in muscle and soft apron. However , crude lipid , total amino acids and flavor amino acids in the muscle of turtle fed by ice fresh trash fish were significantly higher than those of others ( P < 0. 01) . There was highly relativity between the content of total amino acids , essential amino acids , flavor amino acids in muscle and soft apron of turtle and the content of them in feed (r1= 0. 7843 , r2 =0.9062 , P < 0. 01) . The results showed that there were some effects of feed on the flavor and nutritional value of turtle.

Abstract:By means of capillary gas chromatography column , fatty acids composition in diploid and trploid Japanese scallop ( Patinopecten yessoensis) was studied. The main results were as follows : ①The composition of fattyacidsinmuscleandmantlewassimilartobothscallops.Theywereall PUFA >SFA >MUFAandn23PUFA >n26PUFA. The main fatty acids were 22∶6n23(23.9%-28.9%) ,20∶5n23(17.6%-20.6%) ,16∶0(11. 0 % -19.4%) ,18∶0(7.3%-8.1%) and 20∶4n26(2.8%-5.5%); ②Diploid and triploid scallop had similar kinds of fatty acids in gonad ,but there were significant differences in the contents of fatty acids between the two scallops ,in which triploid scallop had significantly higher levels of SFA and MUFA ,but lower level of PUFA in gonad than those of diploid scallop ( P < 0. 01) .

Abstract:The lipopolysaccharide ( LPS) was isolated from the cell wall of a bacterial pathogen Pseudomonas maltophilia which was separated from Trachinotus ovatus cultured in Hainan Province. And then, it was immunized to healthy Trachinotus ovatus by the single i. p. injection, double i. p. injection and oral administration, respectively . The result s showed that, w ithin 2- 12 weeks after the f ish was inoculated with LPS, its agglutinating antibody titers against dead Pseudomonas maltophilia and its resistance to the bacterial pathogen Pseudomonas maltophilia increased signif icant ly. Moreover, the phagocytic act ivity of the leucocytes of Trachinotus ovatus also increased after it was immunized with LPS prepared from Pseudomonas maltophilia.

Abstract:A survey on the massive death of cultured scallop , Chlamys f arreri was carried out in Jiaozhou Bay in 2000. The environmental factors including salinity, temperature, dissolved oxygen, pH, COD, and NH4+ 2N were investigated , also the pathology of diseased scallop sampled in the period of massive death was studied. The diseasefirst occurred on 6Julyandreacheditspeakstagefrom 21 to 27 July, thensubsidedinthe earlyAugust. The results showed that the cumulative mortality of cultured scallop reached 90. 0 % on 3 August and the monthly highestmortalitywhichnormallyappearedinJulywas 58.0%. Thehighestdailyprevalencewhichoccurredon 24 Julywas 14.5%. Indoorexperimentsprovedthatthe diseasedscallops diedcompletelywithin 2to 3days. The shell height of scallop averaged 5. 0 ±0. 9 cm in the period of massive death. Half of the cultured scallop died on 23 July. The results of investigating and analyzing of the environmental factors , causes of disease and observation of pathology showed that the massive death of scallop was possibly caused by a certain factor of organism such as virus , whereas it has no direct relations with environmental factors.

Abstract:The complete gene of RTV DNA methyltransferase ( MTase) was amplif ied, cloned and sequenced. The ORF consists of 642 bp which codes for a protein of 214 aa with a predicted molecular mass of 24. 8kD. Sequence analysis of MTase gene shows much higher identity to the species of genus Ranavirus ( 96% - 97%) than to lymphocystis disease virus( 56% ) , the type species of the genus Lymphocystivirus, indicating again that RTV was the member of the genus Ranavirus; just as the other vertebrate iridoviruses, the MTase gene of RTV contains the first four highly conserved motif s of cytosine MTases but the fifth motif, reponsible for DNA binding specif icity, is missing; Among the virus of RTV, doctorfish iridovirus and largemouth bass ranavirus, the very different identity between MTase and MCP gene suggests that the gene used as target to estimate the evolution of the iridoviruses should be suitable.

Abstract:The current status and importance of preserving fish germplasm resources were described. The basic principle of cryobiology and its application potentials in preservation of aquatic germplasm resources were examined. The mechanism of cryodamage was discussed. The recent advances and major problems in finfish gamete and embryo cryopreservation were reviewed. The prospects for cryopreservation research in fish gametes and embryos were looked into. The important research directions in cryopreservation of aquatic organisms were proposed.

Abstract:Geographic information system (GIS) is a powerful tool to store, to manipulate and to analyse large spatiotemporal data and it has been applied to the research for marine fisheries since late 1980. s. The development of marine fishery geographic information system can be divided into three phases: mapping, electronic atlas and information system. It has been used in evaluation of fish habitats, relating fish distributions to environment, site selection for mariculture and building the position related fishery database, etc. And it can also be applied to the fishery modeling, artificial enhancement, fishing quotas management, etc.

Abstract:The natural parent f ish of Engraulis japonicus was caught with bottom trawler f rom Haizhou Bay in the Yellow Sea and the eggs were artif icially fert ilized. The fertilized eggs began to divide in 40min, to be 16-cell stage in 1h30min, late cleavage stage in 2h50min, blastula stage in 5h, closure of the blastopore in 17h10min, hatching in 37h50min after fertilization, and the process of embryonic development was about 38h at 21. 6~ 24. 0 e .

Abstract:Electron microscopic examinations of ultrathin sections reveal the presence of spherical virus-like particles in the digestive gland, kidney, and the intestine of moribund scallop Chlamys farreri collected during a severe mortality in Jiaozhou Bay ( Qingdao , China) in 2000. The virions are approximately 130 to 170 nm in diameter and have a bilaminal envelope, while the nucleocapsids are 90 - 140 nm. The virus occurs and distributes in the cytoplasmic vesicles of infected cells, and it is arranged in a scattered form without occluding protein. The viral part icles are consistent in size and morphology in preparations derived from the isolation and also from ultrathin sections. The spikes of envelope are clearly observed with negative staining. By the same methods, this virus was not found in the healthy scallop, indicating that this virus might be the causative aetio logy for the abnormal mortality.

Abstract:A reverse transcription polymerase chain reaction ( RT-PCR) was used for detection of infectious hypodermal and haematopoietic necrosis virus ( IHHNV) from the gills and subcutaneous tissue of Penaeus vannamei ( 10- 15cm in body size) without clinical signs. With primers 77012R and 77353F, a fragment of 356bp of IHHNV was amplif ied in RT-PCR. The amplified product was sequenced and showed more than 98% homologue with the sequences of other IHHNV strains in Gene Bank.

Abstract:According to the biological investigation of Zhongjieshan Islands tideland and on the base of advanced principle of dividing of the benthic algae , we studied the species composition and the limits distribution of the benthic algae. The paper also advances some suggestions about how to process the ecology protecting and realize sustained exploitation of those recourse after analysing some interrelated questions about resource peculiarity , exploitation and utilization of the benthic algae in Zhongjieshan Islands tideland.