Abstract:The histological development and ultrastructure of larval turbot skin were studied by both light and transmission electron microscopes.The early larvae showed a complete bisymmetry of skin.The skin of 1-25days old larvae developed slowly and was composed of the thin epidermis of 1-2layers epidermal cells and undeveloped dermis before the metamorphosis.But the skin developed significantly when the.metamorphosis began.Till the completion of metamorphosis(about 60days old),the skin contained 3-4layers epidermal cells and very developed collagenous strata.Wisth the process of metamorphosis,the ocular side skin and blind side skin became different in ultrastructure.Ultrastructural observation showed the epidermis of turbot contained three types of epidermal cells;filament-containing cells,mucus cells and chloride cells.The ocular side epidermis with looser structure consisted one type of filament-containing cells,but the blind side epidermis was structured densely and two types of filament-containing cells were observed in it.Melanophores,iridophores,fibroblasts and other cell types and tisssues were found in the spongiosum of dermis.The distribution of melanophores depended on the larval developing stage and the pigmentation of skin.The differentiation of skin seems to be an adaptation for the change of life style of turbot larvae from pelagic living to benthonic living after the metamorphosis.

Abstract:Some changes of growth rate, pigment content, SOD act ivity , POD activity, CAT act ivity and ultrastructure of Haematococcus pluvialis exposed to different dosage ultraviolet radiation have been studied, the results showed that only little ultraviolet radiation is lethal for H . pluvialis, and more microalga be died with longer illumination time till all microalga died after 8 minutes exposure, while the survivors exposed shorter than 4 minutes have higher growth rate than the control group. There is more chlorophyll and carotenoid content in the cell with longer radiation time, and remarkable increase of astaxanthin content after being radiated between 4- 5 minutes has also been discovered. Contrary to the decrease of CAT activity, SOD activity has much increased to resist the ultraviolet radiation till both losing activity after 5 minutes exposure when some of their organelles were damaged inreversibly by ultraviolet radiat ion, such as chloroplast, plastosome and Golgi body, and POD activity has also much increased after 3- 5 minutes exposure.

Abstract:The major histocompatibility complex ( MHC) of fish was used to study the genet ic structure as a molecular genetic marker of four populations of red common carp. Based on reported common carp MHC class .. gene sequences, a pair of specific primers was designed, MHC class .. molecular ..2 gene fragments were amplified from Xingguo red common carp ( Cyprinus carpio var. singguonensis ) , purse red common carp ( C. carpio var. wuyuanensis ) , glass red common carp ( C. carpio var. wananensis) , and Oujiang color common carp ( C. carpio var. color ) , then cloned and sequenced. The polymorphism of encoded MHC class ..molecular ..2 chain gene was rich, with 106 variable loci in 234bp in length. The percentage of polymorphism was 45. 3%, among the four populations, purse red common carp was significantly dif ferent from the other red common carps. The phylogenet ic trees constructed by encoded MHC class ..molecular ..2 chain gene and its amino acid sequences indicated identically, and the relationship between Xingguo red common carp and Oujiang color common carp was clo ser, belonging to one evo lutionary branch, whereas glass red common carp and purse red common carp belonged to the other two different evolutionary branches respectively. The purse red common carp is a more specialized group. The rich polymorphism of encoded MHC class .. molecular ..2 chain gene is suitable as a molecular genetic marker for different populations of common carp.

Abstract:This paper deals with the digestive enzymes activities change of Haliotis diversicolor diversicolor and H .diversicolor aquatilis in different stages .The results suggest that the activities of cellulase increase with the growth of H .diversicolor diversicolor and H .diversicolor aquatilis , while the activities of amylase decrease with the growth of the H .diversicolor diversicolor and H .diversicolors aquatilis .Also , the activity of digestive enzymes in H .diversicolors aquatilis is higher than that in H .diversicolor diversicolor .And the activity of lipase is very low in both H .diversicolor diversicolor and H .diversicolor aquatilis .

Abstract:With the technology of PCR, the completed ..-hemolysin gene AHL316HEM was obtained from the amplification of an Aeromonas hydrophila strain ML316 ( isolated from diseased Anguilla anguilla ) . The gene was cloned into pGEM-T Easy Vector. After analysis, the gene was inserted into pcDNA3. 0 vector to construct the recombinant plasmid PDLH. The E . coli DH5..w ith PDLH could lead to obvious ..-hemolysis plaque in blood-Agar. The hemolysis activity of crude purif ied transformant.. s extracellular products( ECP) was 1. 28 .. 104HU..mg- 1. Furthermore, the transformant.. s ECP could be recognized by ant-i serum which was raised against original bacterial strain. The above results demonstrated that the ..-hemolysin gene of ML316 had been cloned and the recombinant plasmid PDLH could express the product with native bio logical function. The success of cloning and expressing the ..-hemolysin gene of A . hydrophila will speed up the development of DNA vaccine against A . hydrophila.

Abstract:The impacts of some inducing substances on the settlement and metamorphosis of planktonic larvae of the abalone Haliotis discus hannai were studied. According to the composition of amino acid in 6 monocultured benthic diatom, 15 artif icial synthetic amino acids were chosen as the inducer. The results of the inducing experiments showed that the highest settlement rate appeared in the group with L..aspartic and the second in L.. glutamic test group. These two rates were a little lower than that of benthic diatom test group and much higher than control group. About inducing metamorphosis rate, L..aspartic test group and L..glutamic test group are same. Both are a little higher than benthic diatom test group and are much higher than the control test group. The experiments w ith different concentration of inducing substances indicated that the highest inducing rates occurred when the concentration was 10- 5mol..L- 1for both L..aspartic and L..glutamic acid.

Abstract:This article reports the morphology, densit ies and distribution characteristic of 13 dinoflagellate resting cysts in sediment of Xiamen Harbor. The preliminary study showed that the average abundance of dinof lagellate cysts is 3360 ind..kg - 1 ( wet sediment ) . Among them 2 species are toxic ( Alexandrium tamarenes, A. minutum) and 2 species are harmful ( Gonyaulax spinif era, Scripp siella trochoide) . These 4 toxic and harmful dinof lagellate cysts are rich in the sediments of Xiamen Harbor. They will be harmful to the aquaculture in Xiamen Harbor and human health when the environmental factors are appropriate.

Abstract:Pneumatophorus japonicus and Decapterus maruadsi are the main pelagic f ishes in the East China Sea, the formation and the spatio-temporal variety of its fishing ground is restricted by the change of environmental factors. It is very significant to research the formation mechanism of central fishing ground and explore their relation for knowing the law of migration and distribution of Pneumatophorus japonicus and Decapterus maruadsi and rationally using and protecting marine fishery resources. Based on the data of marine environmental investigation in the west of 29- 32bN, 124. 5bE from 1987 to 1990, in the platform of GIS, using moderate statistic method, the study has been conducted on analyzing the relation between central fishing ground and some factors of marine environment and its alterat ion as the time and space change, then on determining the main effectual factors of fishing ground formation, and researching the mechanism of the formation of f ishing ground. On this basis, a mathematical model is established by using fuzzy set theory. Numeric examination educed that of using the grade of membership of 75% as the criterion. Using the data f rom 1987 to 1990 and that of 1997 to check the model, it is found that, applying the model to f ishing production, a good result would be gotten. The conclusion is that, the characteristics parameters, bottom temperature ranges from 19. 0 e to 21. 0 e , bottom salinity ranges f rom 33. 0 to 34. 5, and the prey biomass ranges from 137 to 409mg#m- 3 and the square of correlative coeff icient of bottom temperature and salinity can reach 0. 9935 and 0. 9988 respectively, which indicates their relation is very consanguineous. The method, that establishes the mathematical model and applies it to study the formation mechanism of central f ishing ground of Pneumatophorus japonicus and Decapterus maruadsi in the North of East China Sea so as to predict the parameters of f ishing ground as the change of time and space, will, to some extent, compensate for the deficiency of qualitative analysis.

Abstract:Penaeus vannamei juvenile was cultured making use of the system of treating circulation water with ozone and bio-filter indoor at estuary area. The circulation water was treated with ozone and bio-f ilter for 2h at 48 - 72h intervals, then aired for 2h. The water circulation among treating pond and shrimp ponds was temporarily stopped, filtering system continually ran during treating water. The quality criteria of the circulation water for the shrimp juvenile culture was controlled within suitable range for 52d. The average values of the criteria are as follows: NH3- Nt 0. 41mg#L- 1, NO- 2 - N 0. 057mg#L- 1, COD 10. 12 mg#L- 1, oxidat ion-reduction potential ( ORP) 379mv, turbidity 0. 6 NTU, bacterial total 10 200 cell#mL- 1, vibrio total 6cell#mL- 1, juvenile survival rate 78. 3% - 80. 2%. The mode of treating circulation water of indoor shrimp culture at estuary area is put forward according to the test result and the characteristic of estuary water.

Abstract:This paper f irst reports the splenomegaly disease of seawater-cage cultured Lateolabrax japonicus. The main symptom of diseased fish is splenomegaly. Mortality rate of diseased f ish reaches 50%. Neither parasites were found on body surface, gill filament s and other organs by microscope exmination, nor pathogenic bacteria isolated from internal organs. However, under an electron microscope, a lot of virus part icles were observed in spleen and liver of the diseased f ish. The virus was a non-envelope with hexagon in section and about 180- 220nm in diameter. The virus was assigned to Iridoviridae. Cytopathological changes showed that the cells swelling and ultrastructure broke w ith large area vacuoles in cytoplasm. A lot of distinctive lymphocytes were found in blood cells, which occupies 50% of the total number of the lymphocytes.

Abstract:The nutritional components and proteolysis of oyster meat were investigated. The result s showed that the gross protein and glycogen in oyster meat were 50. 63% and 22. 41% respectively. The distribution of amino acids was perfect, and the total quantity of 8 essential amino acids accounted for 40 percent of total amino acids. The 537 acid protease was suitable for the proteolysis of oyster, and the optimal conditions were: E/ S= 1700U ..g - 1 protein, pH4, 50 .. and 2 hours. In the optimal condition , the yield of soluble protein and glycogen reached 78. 23% and 50. 58% based on that in raw material respectively, and the total free amino acids and taurin were 39. 27% and 12. 47% based on the total amino acids in the hydrolysate respectively.

Abstract:As lower vertebrates, f ishes have complex modes of sex determination. From the cytogenet ic perspective, only a small proportion of f ish species have heteromorphic sex chromosomes. At the present stage sex determination can only be explained via .. genetics.. rather than .. genes.. in most species. Nevertheless, genes associated with sex determination and male development were identified in a model fish medaka, Oryzias latipes. Sequences or genetic markers specif ic to certain sex chromosomes were reported in some f ishes. These f indings lay the groundwork for further studies on the function and regulat ion of sex genes aiming at elucidation of the mechanism of sex determination, and provide potential tool for sexing f ish. In this mini..review , progress in the past few decades in both cytogenetic and molecular genetic studies on sex determination of f ish were summarized. Prospects, signif icance and possible future directions of the studies on fish sex determination were also discussed.

Abstract:Larval digestive organs of Amur sturgeon, Acipenser schrenscki and hybrid sturgeon(Huso Huso .. .. A. schrenscki .. ) hatched out at 17~ 21 .. were successively observed under Olympus microscope after being sectioned. Histological development of yolk- sac, pharyngeal cavity, esophago, stomach, intestine, pyloric caecum, liver and pancreas is described. It shows that the development of the digest ive organs of the two f ishes is similar to several other Acipenseridae f ishes. Characters of the digest ive organs about the two fishes and the relationships among earlier development period, ingestion, digestion and absorption are discussed.

Abstract:The histology , evolution of the structure , composition and morphology of oogonia and primary oocytes in different phases during the ovary development of snakehead , Channa scopoli , were studied .The traditional method of wax section was employed to perform the hematoxylineosin staining .The ovary of snakehead is overlaid by the 2-layer membrane featured with abundant veins .The primordial germ cell of ovary extends into the ovary together with the inner connective tissue membrane to develop into many ovarial lamellae that arrange radiately around the ovarium cavity .With regard to the developing snakehead , the pattern and structure of its oogonia and early primary oocyte are of fundamental homology with most of the osteichthyes , while the nutrimental composition , accumulation , distribution and the composition of ova membrane for the primary oocyte in phase Ⅲ and Ⅳ are of preferable difference with them.The nutriment of its oocyte is primarily composed of glucoprotein which is included in the vesicle .But the amount of yolk which is primarily composed of protein is comparatively small , even the same for the oocyte developing into the phase Ⅳ which is featured with the deviation of nucleus .So the amount of nucleoli in the primary oocyte of the snakehead is significantly limited than most of the osteichthyes .The primary oocyte in phase Ⅲ and Ⅳ of the snakehead only have 1 layer of ova plasmalemma which is covered by another 2 layers follicular membrane developed from the follicle cell , but there is not any radiated belt of jelly membrane between the membrane and the follicular membrane which is developed from the primary ova membrane and the secondary one in most of the osteichthyes cases .

Abstract:The mature parent fish of Trichiurus lepturus was caught with bottom trawl on board R/ V .. Beidou.. in the Haizhou Bay, Yellow Sea. The running eggs were artificially fertilized. The fertilized eggs began to divide in 1h30min, to be 16-cell stage in 2h55min, late cleavage stage in 4h25min, blastula stage in 10h30min, closure of the blastopore in 25h45min, hatching in 78h45min after insemination, and the process of embryonic development was about 79h at 20. 6- 22. 6 .. .