Abstract:The metamorphosis and skin melanophores of turbot , Scophthamus maximus ( Linnaeus ) , were investigated. The morphological developments and changes of body color at different stages of 1 to 60 days old larvae were observed and photographed. The whole period of early development of turbot lasted about 60 days in spawning water at 14 -17 ℃. The morphological development of larvae could be divided into three stages : development of organs (1 -14 days old) , development of morphology (14 -40 days old) and completion of metamorphosis (40 -60 days old) . Metamorphosis occurred about 25 days after being hatched , and the larval melanophores of fry body were distributed symmetrically , with an increase of the density firstly and a decrease of the density followed. When metamorphosis occurred, the body color of fry became asymmetrical. On ocular side, larval melanophores of fry body disappeared and were replaced by adult ones. On blind side, the larval melanophores disappeared and no adult ones appeared. Albinism would occur if the development of adult melanophores on the ocular side of turbot was blocked.

Abstract:Total RNA was isolated from silver carp ( Hypophthalmichthys molitrix ) pituitaries. The cDNA fragment of 1. 2 kb encoding growth hormone ( GH) was amplified by reverse transcription polymerase chain reaction (RT- PCR) using total RNA as template. The amplified cDNA was inserted at the EcoRI site in vector pBluescipt KSII + and resulted in plasmid pBS - scGHcDNA. GH cDNA fragment of 1 kb w ithout signal peptide sequence was amplified using pBS - scGHcDNA as template and introduced to expression vector pRSET5b, generating scGH expression plasmid pRSET5b - scGH. The bacteria BL21 ( DE3) plys were transfected with pRSET5b- scGH. The expression of scGH peptide of 22kD in the transfected BL21( DE3) plys was detected by PAGE. Western blotting demonstrated that the recombinant scGH could specially react with monoclonal antibody to grass carp ( Ctenopharyngodon idellus ) GH.

Abstract:Somatostatin secreting cells ( named D cells also) in whole digestive tract of mud eel were showed with ABC immunohistochemical method in cured gut paraff in section. The somatostatin secreting cells were only presented in gastric body, scattered mainly in gastric gland and a few were showed in mucous epithelium. According to cytoplasmic process of their bottom , four endocrine cell types could be distinguished in digestive tract and they all were presented in stomach of mud eel, but the number of type ó was the largest , types . and . were next, type ò was the smallest. D cells producing somatostatin had the most functions and the most complex types among endocrine cells in digestive tract, so stomach of mud eel was also an important endocrine organ. Epithelial cell of gastric gland observed with electron microscopy contained lots of tubuloresicular systems and some zymogen granules, which showed it could secrete acid and produce zymogen, so it belonged to oxynticopeptic cell. Apical membrane of intestinal epithelial cell contained lots of microrillis. Microrillis of juvenile mud eel were longer, denser and t idier that those of adult mud eel, which showed absorbability of juvenile mud eel was stronger than absorbability of adult mud eel.

Abstract:Use of a vitrified solut ion ( composition 10) as a cryoprotectant for the cryopreservation of loach embryos is studied in this paper. Using this vitrif ied solution, embryos were preserved at a temperature of - 196 e for 17 hours. Afterward, the preserved embryos were thawed using thawing so lution in warm water ( 38 e ) , and revival embryos were successfully obtained. During thawing, we compared 3 kinds of thawing solution compositions ( B1, B2 and B3) , and the survival rates of the preserved embryos after thawing in B1, B2 and B3 thawing solutions were 26. 7% , 15. 0% and 3. 0% respectively. After thaw ing, it took 50 hours for the development of revival embryos from the interval of blastopore closure to the interval of caudal fin appearance.

Abstract:The ecological conversion efficiencies of 8 fish species in the Yellow Sea and the Bohai Sea and main influence factors were studied by laboratory and in situ methods. Moreover, results determined by laboratory method were compared with those by in situ one. The results showed that : (1) There were significant differences among ecological conversion efficiencies of 8 fish species. The change range of food or energy conversion efficiencies of the fishes were 12. 9 % -39. 0 % or 14. 8 % -46. 1 % respectively. (2) Both of the specific growth rates and ecological conversion efficiencies changed along with differences of following ecological and physiological factors , such as temperature , body weight , feeding level , food species and social behavior etc. The ecological conversion efficiencies tended to show inverted ”U ”change with rise of temperature and feeding level , and decelerating decrease with body weight increment. The feeding levels and specific growth rates could be significantly changed by differences of food species and social behavior , but energy conversion efficiencies could not. (3) There were significant differences , which changed with different fish species , between the results determined by laboratory and in situ methods.

Abstract:The effects of environmental factors on the filtration rate of the constricted tagelus ( Sinonovacula constricta) were studied in laboratory. The results showed that the water temperature , salinity and pH had distinct effectsonthefiltrationrateoftheconstrictedtagelus. Themaximumfiltrationrateappearedattemperature 20 ℃. The filtration rate increased with the increase of salinity in the range of 6～30. It increased with the increase of p H value in the range of 6～8, and decreased at 9. The maximum appeared at pH 8.

Abstract:The variation of chemical environmental factors in the water ecosystem , bacterial population and cultured organisms in the freshwater fishponds was studied after applying salt2resistant Rhodospirillaceae bacteria to culture Ictalurus punctatus and Pengze crucian. The results showed that the NH4 + -N ,NO2 --N ,NO3 --N and COD content decreased and dissolved oxygen and pH increased in the water ecosystem after sprinkling Rho. capsulata in the fishponds. The change of bacterial population and quantity was as follow : The amount of photosynthetic bacteria , nitrous bacteria and nitric bacteria rose 3 -50 (majority 15 -20 times ) , 3 and 4 -5 times respectively. The amount of major heterotrophic bacteria Enterobacteriaceae rose 9. 4 % and Aeromonas reduced 7. 5 % in the Ictalurus punctatus fishponds ; Pseudomonas reduced 16 % and Enterobacteriaceae rose 21 % in the Pengze crucian fishponds. The cultured effect of the cultured organism was that the average increasing rate of weight of every Icthlurus punctatus fry and Pengze crucian fry rose 15. 7 % and 12. 8 % respectively.

Abstract:Glucose to lerance test was performed with allogynogenetic silver crucian carp( Carassius auralus gibelio a @ Cyprinus carpio ` ) , whose initial weight was 46 ? 5g, after the f ish had fasted for 4 weeks. Blood and liver were collected before and 1, 2, 3, 4, 5, 6, 8, 10, 14, 18 and 24h af ter being administered orally with 167mg glucose per 100g body weight . The results showed that the plasma glucose level increased sharply during 3h and reached a peak at 3h after oral administration, and then decreased slowly. Plasma triglyceride peaked at 1h after administration and thereafter started to decrease, which re-increased after 8h. During the first 2h after glucose administration the liver glycogen content decreased significantly, and thereafter increased to a peak value, which was reached 6h after glucose administration. Different doses of glucose were administered to the same species , which had fasted for 4 weeks and whose initial average body weight was 164 ? 12g, to investigate the change of plasma glucose level and liver glycogen content. The results showed that with the dose of glucose increasing , the plasma glucose level increased. However, the liver glycogen content decreased with the increasing of glucose dose. These results indicated that there is native difference in secretion of insulin between allogynogenetic silver crucian carp and mammals.

Abstract:A 3 ×3 factorial feeding trial was made to determine the effect of dietary protein level and lipid level on growth and body composition of Sciaenops ocellatus. Juvenile fish whose initial mean weight was 2.73g were randomly distributed in 27 nets (2. 5m ×1. 5m ×1. 3m) and were fed with test diets containing gradual protein levels (38 %, 42 %, 46 %) and lipid levels (5%, 8%, 12 %) for 8 weeks. It is found that specific growth rates (SPR) and feed conversion ratio (FCR) were significantly higher in fish fed with high protein diets (HP, 46 %) thanthosefedwithmediumproteindiets (MP, 42 %) andlowproteindiets (LP, 38 %) ( P <0.05). No significant difference was found among groups fed with different lipid levels diet in the same protein level ( P > 0. 05) . Viscerosomatic and hepatosomatic index increased with reducing of the dietary DP/ DE. Lipid content of whole body and hepatocrease increased with increasing of the dietary digestable energy. However , protein and ash content and amino acid composition of whole body were not affected by dietary treatment. It is recommended that the optimal dietary protein level and the ratio of protein and digestible energy (DP/ DE) of juvenile Sciaenops ocellatus are 46 % and 119mg·kcal -1.

Abstract:Grass carps (8. 49 ±0. 04g) were randomly assigned to 12 tanks (30 fish/ tank) and fed with three experimental diets , which contained 30 % different types of starch (corn starch , wheat starch and rice starch) for 80 days. Daily feeding rate was 3 % wet weight. The results showed that there was no significant difference in growth of fish fed with wheat starch , corn starch and rice starch , even though highest carbohydrate apparent digestibility coefficients occured in wheat starch fed fish. While viserosomatic index , hepatopancreatic fat content , plasma trigliceride level and percentage mesenteric fat were significantly higher in fish fed with wheat starch than in those fed with rice starch. The differences in body composition were small except that the body fat content of fish fed with rice starch was relatively lower than those fed with corn starch or wheat starch.

Abstract:Four experiment diets were designed (purified diet , practical diet and practical diet with lysine uncoated or coated ) . Grass carp (mean weight of 7. 27 ±0. 5g) were fed separately in 12 fiberglass tanks (100cm ×50cm ×50cm) with 30 fish per tank. Every experiment diet was taken three repeats. The experiments lasted 9 weeks. Results indicated that grass carp fed with the purified diet showed a significantly higher growth ratio and protein synthesis rate ( Ks) than fish fed with the practical diet ( P < 0. 05) . Practical diet with coated lysineimproved the growth rate, feed conversion, balance of essential amino acid in plasma (BEAAp ) and protein synthesis rate ( Ks) in comparison with diet with lysine uncoated or deficiency. Coated lysine , but not free lysine , proved to be a significantly better way of dietary protein supplementation.

Abstract:The effects of DL -carnitine and L -carnitine with different supplement doses (200mg·kg -1DL carnitine , 400mg·kg -1 DL -carnitine and 200mg·kg -1 L -carnitine) on the growth and composition of body of hybrid tilapia ( Oreochromis nilotica ♀× Oreochromis aurea ♂) were studied with a mean body weight of 38. 65 ±0.21g per fish over 34 days. The study showed that the two isomers of carnitine neither improve the growth rate nor alter the composition of whole fish and muscle significantly , but it was observed that the relative weight of viscus was changed and the liver fat decreased significantly ( P < 0. 05) . No clear difference of supplement effects between DL -carnitine and L -carnitine with same supplement dose (200mg·kg -1) was found under the experiment conditions .

Abstract:From June to July 2000, specimens of Meretrix meretrix Linnaeus suffering from the / red muscle disease0(RMD) were co llected from Qinhuangdao District of Hebei Province, China. Abundant virus particles and their virogenic stroma were observed in the cytoplasm of the epithelium of digestive diverticula. The spherica-l shaped virions with the size of 50~ 80nm in diameter lack capsula. The inclusion bodies forming in the cytoplasm are multivesicular which assemble virus particles. In the infected cells w ith virus, the cellular organelles presented obvious pathological changes, e. g. the endoplasmic reticulum swelling and most ly turning into vesicles, the mitochondria dissolving or condensing, the nuclear membrane expanding, dissolving and forming nuclear vesicles, and the number of lysosome increasing.

Abstract:The samples of Penaeus chinensis and Penaeus vannamei were the third and the first generation respectively by selective breeding which have been artificially infected with WSSV. Random amplified polymorphic DNA (RAPD) technique was employed to analyze such samples that were still very healthy over tendayswith 220 primers. 99 distinctivegeneticmarkersaffiliatedwithdiseaseresistanttraitwereobtained,as analyzed , 18 were from P. chinensis disease resistant team with the molecular weight varying from 460 2305bp , and 81 were from P. vannamei disease resistant team with the molecular weight varying from 435 2287bp. Of 220 primers, 77 primersobtaineddistinctivegeneticmarkersfromthetwoteams,amongwhich 3, 2 and 1 distinctive fragments could be obtained from 4 , 13 and 61 primers , respectively.

Abstract:Quality control of fishery product is of importance has been evaluated utmost to fishery product processing industry. fishery product chromatography that are expensive , time consuming and not suitable for real2time application. Development of an efficient and objective technique to monitor the quality of fish is therefore of increasing interest. Electronic nose Traditionally, the freshness of either by sensory organs or by gas has proven to be a rapid , automatic and non2destructive technique for measuring volatile compounds that exhibit spoilage odors in fish. The principle of electronic noses and the development of chemical sensor technology were described in this paper. The application of electronic noses in freshness assessment of fishery product and future prospect were discussed as well .

Abstract:Von Bertalanffy equation was analyzed in theory and compared for fitting with a lot of present data between the power2exponential equation of growth and von Bertalanffy ’s. It was discovered that power2 exponential growth equation was more applicable and fitting than von Bertalanffy’s and was also deduced by modifying von Bertalanffy equation. Comparing with other eight growth mathematical models , the relation index for fitting and applicable range of the power2exponential growth equation was the best in all models.

Abstract:The activity and location of phendoxidase ( PO) in lymphatic organ of Penaeus chinensis were studied by enzyme cyto-chemical technique of electronic microscope. The results showed: 1. Few PO positive reaction in lymphat ic organ of health individual was observed. 2. In the sick, the activity of PO in lymphatic organ appeared in different degree. Observed by electronic microscope, the multiplying and expanding of smooth endoplasmic reticulum in the endothelial cell of lymphat ic tubules were induced by virus invading. Meanwhile, the activity of PO appeared; Many PO positive granular and myelinef igure existed in the cells of lymphatic tubule wall; In the exterior lymphatic tubule, the quantity of virus reduced obviously. PO positive granular in the hemal sinuses can be found secreted from tubule cell. It is inferred: ( a ) PO can destroy virus. ( b) Lymphatic tubules have the effects of filtering haemo- lymph and secreting PO granular.