Abstract:Grey relational analysis was considered to be a useful method to define the relationship among the agronomic characters and yield of different crop populations. But for aquatic animal, there were only few reports that evaluated the relationship among multiple growth traits with the method. To broaden the application of grey relational analysis in fish species, Japanese flounder () was used as targeted animal to demonstrate the statistical efficiency of this method introduced here. This flounder is an important marine fish species and widely cultured in China, Korea and Japan because of its fast growth and delicious taste. In this study, 10 selective and breeding families were produced by crossing wild individuals of Japanese flounder. A total of 9 growth traits and body weight were measured in these families. Grey relational analysis method was used to examine the relationship between main growth traits and body weight in Japanese flounder. The relational coefficients and degrees between each weight were determined according to grey system theory. Based on grey relational degree, a matrix compared with paired comparison was constructed to quantitatively analyze the impact of each growth trait on body weight. The grey relational degrees between each growth trait and body weight were calculated and ranked as follows, total length depth (0.830 7), trunk length (0.827 7), head length (0.803 5), tail length (0.781 2), body depth (0.740 2), snout length (0.665 7), and length (0.654 0). The main controlling factors included total length, body length, peduncle, their affective degrees were as follows, 28.51%, 21.62%, 16.41% and 11.69%, respectively, and the total effective degree reached 78.23%. The analyzed results showed that the values of total length, body length, depth and trunk length had the closest relationship with body weight and these traits significantly influenced body weight. So the four growth traits could be used as important evaluation factors for the Japanese flounder breeding on high yield to improve the selection efficiency. This study provide scientific basis for the Japanese flounder breeding selection on growth traits

Abstract:In Nile tilapia, the mRNA expression level of various sex differentiation-related genes can be affected by high-temperature induction during the critical period of sexual differentiation, triggering sex-reversal from female to physiological male. However, it is unknown whether the effect of high temperature on Nile tilapia () sex differentiation-related genes is period-specific. In this study, the expression of eight sex differentiation-related genes, four heat shock protein genes and two methyltransferase genes were in 8-month-old Nile tilapia under high-temperature (36) treatment by quantitative real-time RT-PCR techniques. The results showed that the expression levels of , which are ovary development-related genes, were down-regulated (, which are testis development-related genes, were not significantly changed (>0.05) under high-temperature treatment. The results differed from those for high-temperature treatment of Nile tilapia during the critical period of sexual differentiation. The expression level of DNAJB1 was significantly down-regulated. The expression levels of were not significantly changed in the gonads of females and males under high-temperature induction. Furthermore, it was also found that high temperature significantly up-regulated the expression level of in the female gonad.

Abstract:In China, is the shellfish of choice for cultivating freshwater pearls; however, there has been very little research on cell and mantle tissue culture. Based on DMEM), this study attempted to optimize modified formula of medium and buffer for mantle tissue and cell culture. The ratio of RNA/DNA as an evaluation index of cell proliferation was determined and, using microscopic observations, tissue culture cells versus time, speed and cell energy were established. Hoechst fluorescent staining of DNA was carried out using 24-, 108- and 120-h cells of culture, and then the three marked cell groups were implanted into the mantle for culture . fter optimization, the buffer and medium improved cell migration from the mantle, the velocity of migration and the significantly increased cell number (<0.05).Cell vitality also increased with incubation time. Cell vitality was maximal for culture at 108 h, with a RNA/DNA ratio of 24.53, but was followed by a significant decline (<0.05).Microscopic observations of cells were in agreement with the determined RNA/DNA index values. When in vitro activity improved and culture conditions increased cell activity, with RNA/DNA values up to 25.45, but vitality declined significantly after 168 h when injected into the cell for activity of cells, it would appear that a living environment has no significant effect on cell viability. Our study provides basic but valuable information for further research on mantle cell proliferation and the establishment of cell lines

Abstract:Hemocyanin is a copper-binding protein that plays a crucial role in the physiological processes of crustacean. In this study, the cDNA-encoding hemocyanin subunit , was cloned using expressed sequence tag (EST) analysis and a rapid amplification of cDNA ends (RACE) approach. The full-length cDNA of MnHc was 2 235 bp, consisting of a 5′ untranslated region of 10 bp, a 3′ untranslated region of 151 bp, and an open reading frame of 2 064 bp. The deduced protein had 688 amino acid residues with a molecular mass of 79.16 kD. Based on a protein similarity comparison, the two copper-binding sites and six histidine residues necessary for stabilization of oxygen-binding were highly conserved. Phylogenetic tree analysis indicated that Exopalaemon carinicauda. Quantitative real-time RT-PCR analysis showed that the gene was expressed in hemocytes, the hepatopancreas, muscles, testis and intestines, with the highest level of expression in the hepatopancreas and the lowest in muscles. After environmental hypoxia and reoxygenation challenge, the relative expression level of in the hepatopancreas was significantly higher compared with the control group at 12 h, 24 h post-hypoxia and 6 h reoxygenation, followed by a gradual recovery at 24 h reoxygenation. The highest titer of antiserum was up to 1120 000, as revealed by ELISA assay. The specificity of antibodies against hemocyanin was verified by westernblotting. The study indicates that the expression levels of in the hepatopancreasmay be affected by environmental dissolve oxygen, and hemocyanin may potentially be involved in the hypoxia stress response of .

Abstract:According to the theory of developmental genetics, genes are expressed selectively at different growth stages in a time- and/or space-specific manner. The whole process of genetic control during development cannot be revealed by data collected at one single time-point; the dynamics of gene expression need to be monitored at various developmental periods during ontogeny. Genetic analyses for body weight trait turbot, at different developmental stages, and statistical methods, including additive and dominance effects for quantitative traits. At the same time, the growth curves of six mating combinations of turbot were divided into four, i.e. slow-growing period, fast-growing early period, fast-growing late period and asymptotic growing period, based on the von Bertalanffyvariance components and the proportion of phenotype variance at the different developmental stages. The results showed thatslow-growing period, fast-growing early period and fast-growing late period of the six mating combinationsslow-growing period, new net additive/he components to phenotype variance of net dominant significantly different. In the fast-growing early period, net additive/significant differencesproportions of net additive/dominant significantly differentfast-growing late period, net additive/dominant were proportions of net additive/dominant significantly different.

Abstract:, is an important genetic resource. To preserve the species, experimental trials were carried out to find suitable sperm cryopreservation methods by comparing the effects of four extenders, D-15, D-17, Ringer’s and M-Hank’s, and five cryoprotectants, dimethyl sulfoxide (DMSO), glycerol (Gly), ethylene glycol (EG), propylene glycol (PG) and dimethylformamide (DMF), on sperm motility after thawing. The present study demonstrates that DMSO and D-17 are a suitable choice as cryoprotectant and extender, respectively. Using a protocol of diluting a sperm sample with D-17 at a sperm/extender ratio of 13, adding DMSO to a final concentration of 10% in volume, loading to 2-mL cryotubes as containers, following the three-step method to cool the mixture and thawing the frozen semen in a 37 water bath for 80 s, a post-thaw motility of >80% could be obtained using computer-assisted sperm analysis (CASA). Single cell gel electrophoresis showed that >70% of sperm DNA was intact and practically no sperm nuclear DNA was severely damaged. Flow cytometric analysis showed that 26.74% of the frozen-thawed sperm had intact membrane and functional mitochondria. The highest fertilization rate was (39.6±6.5)% in the hybridization of (♂). The hatching time was 38 h after fertilization at 24–28 and body parameters after being fed for 7 day were (0.045±0.020) g in weight, (1.346±0.255) cm in length and (0.438±0.103) cm in depth. Thus, it is recommended that D-17+10% DMSO be used for cryopreservation of S. scherzeri germplasm resources and promote crossbreeding with (♀) through the successful application of sperm cryopreservation skills.

Abstract:Clones serve as an important function in immunological, endocrinological, developmental biological, molecular biological and genetic studies; however, poor fertility of doubled haploids effectively hinders the production of homozygous clones, with the result that only a few laboratories have succeeded in producing homozygous clones. Protocol studies and studies into the biological characteristics of clonal fish are well known and ongoing but, to the best of our knowledge, there have been no hematology studies. This research study is a comparative analysis of the hematology of clonal and common Japanese flounder using 10 physiological parameters and 17 biochemical indices. At Beidaihe Central Experiment Station, clonal flounder were produced by gynogenesis that suppressed cleavage of the eggs in mitosis and then blocked the extrusion of the second polar body in meiosis. The results showed that red blood cells (RBC), hemoglobin (HGB), mean corpuscular hemoglobin (MCH) and hematocrit (HCT) of clonal Japanese flounder were significantly lower than that of common Japanese flounder (indices between clonal and common Japanese flounder. In addition, blood biochemical indices – alkaline phosphatase (ALP), cholesterol (CHO) and blood urea nitrogen (BUN) – for clonal Japanese flounder were significantly lower than for common Japanese flounder (<0.01). However, albumin/globulin (ALB/GLB), aspartate aminotransferase/ (AST) were significantly higher for clonal Japanese flounder than for common Japanese flounder. The average coefficient of variation (CV) for the physiological was 5.50% for and 9.21% for common Japanese flounder. The mean corpuscular volume (MCV) coefficient of variation for clonal was only 1.52%. The average blood biochemical indices between clonal and common Japanese flounder were 10.56% and 27.23%, respectively.

Abstract:Low-temperature acclimation is recognized as one of the most important methods of improving cold tolerance. The physiological response and immune function of the fish body could be changed through proper low-temperature acclimation. To elucidate the immune-protective mechanisms of various tilapia strains during low-temperature acclimation, four different strains (GIFT tilapia,hybrid tilapia, red tilapia and Aurea tilapia) were reared at 26. Three weeks later, individual tilapia (body weight 50.73 g ± 4.23 g) were selected and low-temperature acclimation experiments performed. Water temperature was decreased from 26 to 8/d. Blood and head kidney of three fish from each tank were sampled at 26, 20, 14 and 8, and the change in serum cortisol (COR) and immunity indices of the head kidney were compared in the four different tilapia strains over the course of the low-temperature acclimation. The results showed that the levels of serum COR in GIFT and red tilapia at 8 were significantly higher than the other strains. The levels of serum complement 3 (C3), complement 4 (C4), immunoglobulin M (IgM) and the level of c-type lysozyme mRNA in head kidney at 8. COR may play an important role in the regulation of immunity activity and higher levels of COR may inhibit immunity in the fish body. Higher levels of serum COR, C4 and IgM and the expression levels of hepcidin antimicrobial peptides-1 (HAMP1) were observed at 8. The levels of serum COR, C4 and IgM, and expression levels of c-type lysozyme in the head kidney of Aurea tilapia were similar at water temperatures of 8 and 26. At the end of the low-temperature acclimation trial, cumulative mortality of the four different tilapia strains was compared at 8for 48 h. Cumulative mortalities for the GIFT and red tilapia strains were 43.3% and 40.0%, respectively, and were higher than for the hybrid and Aurea tilapia strains. The cumulative mortality of Aurea tilapia was lowest (20.0%). The higher IgM levels in serum and c-type lysozyme and HAMP1 mRNA levels in the head kidney may have enhanced the resistance of the hybrid and Aurea tilapia strains to low-temperature stress and improved survival to cold stress.

Abstract:2 hybrids of ♂ were comprehensively analyzed in six countable morphological parameters, 10 meristic parameters and 24 truss framework parameters. ANOVA showed that the countable parameters of the F₁ and F₂ hybrids were intermediate betweenexcept for the same number of spines in the anal fin. For the meristic and truss framework parameters, the F₁ hybrid was larger than 3-5/total length, 5-7/total length, and O. niloticus in body width/total length, body height/total length, truss parameter /total length, and caudal peduncle height/total length. The F₂ hybrid showed no significant difference with the F₁ hybrid in 16 meristic and truss framework parameters; however, the F₂ hybrid was larger than the F₁ hybrid in head length/total length, truss parameter /total length, and hybrid in body length/total length, caudal peduncle length/total length, truss parameter /total length, and 2 hybrid stock was initially clustered with the F₁ hybrid stock, then they were clustered with . Discriminant fomulations for the four stocks were developed with countable and measurable parameters, and the order of discriminant accuracy for these stocks was 2 hybrid. More F₁ hybrid individuals were assigned to (92.9% in countable formula, 57.1% in measurable formula) than and hybrid individuals were assigned to F₁ hybrids by the discriminant formula of hybrid (68.6% in countable formula, 77.2% in measurable formula). Principal component analysis showed that the scatter plots of the F₁ and F₂ hybrids were distributed between hybrid showed more overlapping with S. melanotheron. The above results showed that the hybrid inherited the morphological traits of their parents with some maternal inheritance. The F₂ hybrid inherited some morphological parameters from the F₁ hybrid, but also showed some distinct variations in other parameters.

Abstract:The potential target of ipu-miR-143 was predicted and identified using a luciferase reporter gene assay with HEK293 and CCK cell lines . Bioinformatic analyses indicated that the 3) contains an ipu-miR-143 target site, which perfectly complements the smature ipu-miR-143 sequence. Therefore, we speculate that the gene might act as a direct regulatory target of miR-143 in channel catfish. The pMIR-EB1 report vector containing the ipu-miR-143 complementary sequence was constructed to investigate the target of ipu-miR-143 in channel catfish. Then, pMIR-EB1 and miR-143 mimics were co-transfected into the HEK293 and CCK cells to detect the biological activity of ipu-miR-143. In comparison with the control groups, the miR-143 mimic groups showed significantly lower levels of luciferase expression in the two cell lines (0.05). Luciferase activity of the ipu-miR-143 inhibitor groups was significantly higher than that of the control groups in the CCK cell line (<0.05). Contrarily, there were no significant differences between the inhibitors and control groups in the HEK293 cell line ( gene could be a target gene of ipu-miR-143 and provide valuable information for further research on the post-transcriptional mechanisms of ipu-miR-143 in channel catfish.

Abstract:

Abstract:We conducted this experiment to determine the optimal dietary methionine requirement of red swamp crayfish (), as was based on the evaluation of growth performance, feed utilization, body composition, muscle amino acids composition and digestive enzyme activities. Six isonitrogenous (28.25% crude protein) and isocaloric (16.07 kJ/g gross energy) diets were formulated with the protein sources originated from casein, gelatin, fish meal, wheat and and crystalline amino acid (AA) mixture. The measured methionine levels of the experimental diets were 0.39%, 0.53%, 0.71%, 0.86%, 0.98%, and 1.13%, respectively. The dietary AA pattern, except for methionine, was applied to the muscle AA pattern of this apecies. Each diet was fed to four groups of 12 crayfish with an average initial body weight of (9.80±0.15) g in floating net cages (60 cm × 60 cm × 60 cm). Crayfish was fed three times daily for 56 d. The results indicated that weight gain rate, specific growth rate and feed efficiency ratio all increased significantly (<0.05) as dietary methionine levels increased from 0.39% to 1.13% with their maximum values all being attained 0.86%, respectively. However, they all decreased with further increasing dietary methionine levels. Survival rate ranged from 83.33% to 91.67%, and showed no significant difference (>0.05) among all the dietary treatments. The highest whole-body protein content was observed in crayfish fed 0.86% dietary methionine. It was significantly (<0.05) higher than that of crayfish fed 0.39% dietary methionine, but showed little difference (>0.05) with that of the other treatments. No significant difference (>0.05) was found in whole-body moisture, ash and lipid content and liver composition and muscle AA contents among all the treatments. The muscle lipid content of crayfish fed 0.98% dietary methionine was significantly (<0.05) lower than that of crayfish fed 0.39% dietary methionine, but showed little difference (>0.05) with that of the other treatments. Intestinal protease activities were significantly (<0.05) affected by dietary methionine levels, whereas the opposite was true for lipase and amylase activities. The second-order regression analysis of WGR against dietary methionine levels indicated that the optimal dietary methionine requirement of red swamp crayfish was 0.94% of diet (and 3.36% of diet protein).

Abstract:An 8-week feeding experiment was conducted to evaluate the effects of galactomannan oligosaccharides (GMOS) on the growth, digestion, nutritional composition of the body wall and immunity of ). A basal diet of 38% crude protein and approximately 1.6% crude lipid was used as the control. The four experimental diets were formulated containing five GMOS levels of 0.2%, 0.4%, 0.8%, 1.2%, 1.6% feed. Each diet was randomly allocated to triplicate groups of sea cucumber maintained in indoor fiberglass tanks (80 cm × 70 cm) with circulating seawater (18.0± 0.5) and constant aeration. Each tank was stocked with 40 individuals with an initial average weight of 1.79 g ± 0.06 g. The results showed that GMOS supplemented at the experimental levels significantly enhanced the weight growth rate (WGR) and specific growth rate (SGR, <0.05); however, there was no significant difference for ). WGR and SGR peaked at the 1.2% (E4) GMOS supplementation level. In addition, GMOS supplemented at experimental levels had no significant influence on intestinal pepsin, amylase and cellulase content (0.05) or on body wall acid mucopolysaccharide level of juvenile sea cucumber (0.05). sea cucumbers fed a diet with 0.2%–1.2% GMOS had a significantly higher body wall amino acid content, including glutamine, glycine and arginine, than the control (<0.05), while those in the 1.6% GMOS group showed no significant difference from the control (0.05). Furthermore, experimental levels of GMOS supplementation significantly influenced superoxide dismutase (SOD), alkaline phosphatase (AKP) and lysozyme (LZM) activity in the body wall and coelomic fluid (<0.05). In conclusion, sea cucumber fed with a GMOS-supplemented diet not only displayed improved immunity but also an enhanced specific growth rate and amino acid composition of the body wall. Considering all parameters, the optimum level of GMOS in the diet of sea cucumber (1.79 g ± 0.06 g) was 1.2%.

Abstract:An 8-week feeding trial was conducted to evaluate the effects of dietary potassium (K⁺) on growth performance, nitrogen metabolism and osmoregulation of the Pacific white shrimp () reared in low-salinity well-water (4 ppt) with a Na⁺/K⁺ of 41.6. A total of 720 juvenile shrimps, with an initial body weight of 0.372 g ± 0.006 g, were randomly divided into six groups. Six experimental semi-purified diets were formulated, containing 0.59, 0.96, 1.26, 1.48, 1.74 and 2.17 g (K⁺) /(100 g diet) as feeding treatments and designated as D0, D1, D2, D3, D4 and D5 group, respectively. After a 56-day feeding trial, the results showed that the weight gain rate (WGR) of shrimps fed with D2 [1.26 g(K⁺)/(100 g diet) ] was the highest (<0.05), but there was no significant difference between D2 and D0 (control). The protein efficiency ratio (PER) of D1 showed the highest value among all treatments (<0.05). There were no significant differences in body moisture, crude fat, ash and protein content (> 0.05) among all treatments. However, body potassium content in D1 had the significantly highest value and D5 the lowest in all treatments (<0.05). increased, the oxygen consumption rate of shrimps fed with the 1.48 g (K⁺)/(100 g diet)<0.05), while the ammonia-N excretion rate of D2 was also the significantly lowest (<0.05). The D1 diet group had the significantly lowest arginase activity (<0.05). However, there were no significant differences in hemolymph ammonia, urea or uric acid levels among all treatment groups ( values decreased and then increased significantly with increased dietary K⁺ (-K⁺-ATPase activity revealed a reverse trend and shrimps fed with the 1.48( K⁺)/(100 g diet) (D3 group) had a relatively higher value than other treatment groups (<0.05)., hemocyanin levels tended to increase and then decrease significantly (<0.05). There were no significant differences between hemolymph osmolarity or potassium ()/(100 g diet) can improve dietary protein utilization and maintain a balance in the nitrogen metabolism and osmoregulation of + of 41.6. Excessive supplementation of potassium [1.5%, total 2.17 g (K⁺)/(100 g diet)] may disturb metabolism and limit the growth of .

Abstract:), was tested attreatment with the was not adjusted and acted as the control. There were group. The n and were recorded breeding cycle, treatments had a significantly better effect on of water In T1 and T2, tsignificantly T3 and T4 , T3 and T4 alkalinity wasinterval of adjustment in adding In the late breeding period, the high alkalinity of the water and filler layer and thus total number of bacteria and nitrogen cycle bacteria were significantly higher than the number in low-alkalinity water. This trend was more obvious with increasing water depth. The mechanism of the ecological impact of mainly affects the number of microbes and microbial decomposition efficiency. The growth of microorganisms and increase in decomposition efficiency reduces ammonia nitrogen and inorganic nitrogen concentrations, and thereby maintains a better growth environment for shrimp and thus the growth of shrimp. In conclusion, in a , ) can effectively increase the number ofthereby improving the amount of alkalinity)

Abstract:To investigate the effects of chlorogenic acid on the antioxidant activity and resistance to low-salinity stress in , 360 shrimps were randomly divided into four groups and fed four diets containing 0, 100, 200 and 400 mg chlorogenic acid/kg(diet). After feeding for 28 days, all shrimps were subjected to an acute salinity change from 32 to 10 for 72 h. Total antioxidant status (TAS), glutathione peroxidase (GPx) and catalase (CAT) levels, and expression of the , were analyzed. The results demonstrated that supplemental chlorogenic acid had no effect on TAS or on GPx activity in the hepatopancreas when shrimp were cultured in natural seawater. Compared with the D0 control group, however, dietary supplemental chlorogenic acid significantly increased GPx and CAT activities, and expression of the gene in the hepatopancreas after feeding the shrimp for 28 days ( in the D2 group [200 mg (chlorogenic acid)kg(diet) ] were higher than in the other groups, at 164.29 U/mg(prot) and 1.61 and 2.14 fold, respectively. After low-salinity stress for 24 h, the antioxidant response was characterized by higher TAS, greater GPx activity and higher gene expression of , i.e. an increase of 31.30%, 27.96% and 170%, respectively. Moreover, TAS, GPx activity and gene expression in the hepatopancreas in shrimp that were fed diets supplemented with chlorogenic acid were lower than those of the D0 group (. The results indicate that chlorogenic acid could effectively inhibit dramatic changes in antioxidant enzyme system activities of shrimp exposed to low-salinity stress. After low-salinity stress for 72 h, TAS, GPx and CAT activities and gene expression in the hepatopancreas of shrimp that were fed chlorogenic acid were higher than the D0 group. In conclusion, chlorogenic acid induces antioxidant system activity and plays an important role in resistance to low-salinity stress in .

Abstract:A high-performance liquid chromatography (HPLC) method was optimized for the determination of the free amino acids and flavor-enhancer nucleotides in aquatic products. The flavor-enhancer nucleotides and amino acids of ) were determined to provide basic data for exploiting shellfish seasoning compounds. After sample preparation using purified water, free amino acidsDabs-Cl) pre-column derivatization and reversed-phase HPLC. The best separation was obtained using a 17 mmol/L citric acid solution (pH 6.4, containing 4% dimethylformamide (DMF)) and acetonitrile (containing 4% DMF), gradient elution and a detection wavelength of 436 nm. Flavor (pH 4.5, 5 mmol/L tetramethylammonium hydroxide (TMAOH)) and acetonitrile, and a detection wavelength of 254 nm. This method displayed better precision and higher accuracy in meeting the analytical requirements. Recoveries varied from 90.2% to 108% and RSD varied from 0.7% to 7.1%. The results showed that high levels of taurine, and glutamic acid were found in Pacific oyster; glycine, taurine and alanine were the principal free amino acids in Farrer’s scallop and high percentages of glycine, taurine and alanine were detected in sunray surf clam. The taste activity values (TAVs) of alanine and glutamic acid in the three shellfish were >1; only the TAVs of glycine in Farrer’s scallop and sunray surf clam were >1, indicating that they make a significant contribution to taste. Regarding flavor-enhancing nucleotides, Pacific oyster contained more (IMP), accounting for 80%, while Farrer’s scallop contained the highest adenosine monophosphate (AMP) level followed by IMP; sunray surf clam contained IMP only. Although the concentration of flavor-enhancing nucleotides in three shellfish were low and TAVs were <1, the synergistic effect between nucleotides and amino acids has an important impact on shellfish flavor. Pacific oyster, Farrer’s scallop and sunray surf clam from offshore Yantai are rich in taste, and the flavor-enhancing nucleotides and amino acids, such as taurine, are valuable for human health. The study also provides basic data for the extraction of active substances for the preparation of seafood seasoning compound

Abstract:As the last undammed tributary of the upper Yangtze River, Chishui River is an important protected aquatic habitat. There is a very close relationship between phytoplankton and the aquatic environment. Changes in phytoplankton composition and distribution are regularly used as indicators in environmental monitoring. Furthermore, phytoplankton community structure can be affected by changes in the environment. In this paper, the relationship between the phytoplankton community structure and aquatic environmental factors in the Chishui River was analyzed. Phytoplankton data and aquatic environmental factors were obtained from research investigations in the Chishui River National Nature Reserve for Rare and Endemic Fishes in the Upper Reaches of the Yangtze River during 2007 to 2010. The investigations were usually carried out each year in June, September and December. The investigations recorded 517 phytoplankton species belonging to eight phyla. Species of Chlorophyta and species accounted for 17.83% and 10.61%, respectively, while species totaled 1.98% and 1.34%, respectively. Phytoplankton species of accounted for 0.70%, 0.93% and 0.50%, respectively. Regarding phytoplankton density and biomass, to 28.31×10⁴ cell·L^{, respectively, at the fish breeding stage. At the fish fattening stage, average value for density and biomass ranged from 10.32×104 to 33.73×104 cell·L, respectively, while at the wintering stage the average values ranged from 11.53×104 to 26.38×104 cell·L, respectively. For phytoplankton community biodiversity, the average Shannon–Wiener’s diversity index (J) were 4.42, 6.93 and 0.84, respectively. The community biodiversity results indicate that most sampling sites in the Chishui River were unpolluted, except for the Tucheng sampling site. The relationship between phytoplankton community structure and aquatic environmental factors was analyzed by canonical correlation analysis (CCA). The result of CCA indicated differences in the phytoplankton community structure at the three sampling stages. The aquatic environmental factors, including -N) and total nitrogen (TN), had a major influence on the phytoplankton community structure at the fish breeding stage,) was the main influencing factor at the fish fattening stage, while ) and water temperature (WT) were significant factors at the fish wintering stage.}

Abstract:In fishery research, the study of ichthyoplankton is important in evaluating the ecological restorative effect of artificial reefs. During 2010 and 2011, the species composition and distribution patterns of ichthyoplankton on two artificial reefs in the Laizhou and Zhaoyuan area and in Laizhou Bay were investigated to provide reference data for research on the fish attraction and ichthyoplankton shelter effects of artificial reefs. Within the Laizhou (37°15′–37°18′N, 119°49′–119°53′E) and Zhaoyuan (37°31′–37°33′N, 120°11′–120°13′E) investigation areas, six sampling stations were established inside the artificial reef areas and, as references, three and one stations were established outside the reef areas, respectively. The distribution patterns of ichthyoplankton were investigated by horizontal tows associated with vertical tows via a zooplankton net (145 cm in length, mouth diameter 50 cm, and mouth area 0.2 m²). The horizontal tows were carried out at a speed of 2.0 nmile/h for 10 min at the sea surface, while the vertical tows were carried out from the bottom to the surface at a speed of 0.5 m/s at each sampling station. The results indicated that 16088 eggs and 2487 fish larvae, belonging to seven orders, 14 families, 19 genera and 19 species, were collected in 2010. Among fish eggs, the majority were Clupeiformes, followed by Mugiliformes. Among fish larvae, the majority were Mugiliformes samples, followed by Beloniformes. In 2011, 9 948 eggs and 1 778 fish larvae, belonging to four orders, 14 families, 21 genera and 21 species, were collected, of which the majority were Perciformes for both fish eggs and larvae, followed by Clupeiformes. The unique dominant fish egg species in both the Laizhou and Zhaoyuan investigation area was had the highest dominance but was not the dominant fish larval species in the two areas. Ichthyoplankton community stability was greater in summer, followed by spring. According to the distribution pattern of ichthyoplankton resources, the biomass of ichthyoplankton was higher inside the artificial reef areas than the outside areas. Comparative analysis showed that the biodiversity of the ichthyoplankton community within the artificial reef areas was higher than the outside areas. However, species with low trophic levels and small-sized adult fish formed the majority of ichthyoplankton within the study areas, indicating that a long-term process is involved in monitoring and evaluating the conservation and restorative effect of artificial reefs on marine biological resources.

Abstract:during the reproductive behavioral ecology, its reproductive behavior such as the first time of sexual maturity, mating system, mating behavior, reproduction season, hole behavior and care of young features was studied in this paper. In the main breeding season of original crayfish, such as shrimp mating and spawning of the field natural acquisition samples are into experimental observation statistics, the number of every batch collection shrimp samples is more than 30, body mass ranged between 15 g and 40 g. Our results show that: 1) With fast growth and early sexual maturity, the individual can reach sexual maturity after 612 months. 2) It spawn generally in autumn and winter, but its mating and breeding period are extensive; mating behavior can be ob the mating rate was 20% and the egg laying was zero in July (12.56 g); the mating rate was 45% and the egg laying was 5% in August (1the results of experiments showed that Aug., Sept., and Oct. are its mostly mating seasons, and Oct., Nov. and Dec. are its spawning fastigium. 3) there was sexual in mating system, male and female sex ratio showed loosely, and repeated mating generally. 4) it showed a hole tendency obviously. Burrowing feature is one of the most significant outstanding habits in . It seems as a survival and reproductive strategy on adaption, mating, spawning, hatching, care and so on. Holing behavior in different season indicates different biological function. The aim of this study is to supply theoretical basis for its artificial breeding and breeding production.

Abstract:The culture of fish in cages has been shown to be economically efficiency; however, it produces large amounts of fish feces and uneaten food. These organic waste materials, containing significant levels of carbon, nitrogen, phosphorus, etc., can cause environmental damage and may result in decreased dissolved oxygen levels within cages, negatively affecting fish production. During an exploration of benthic taxa beneath cage culture, numerous nereids were recorded, including , an important seashore species of polychaete, feeding in the sediments. In the present study, a system of fish cage culture and were combined in a 40-day laboratory experiment to investigate the carbon/nitrogen budget and its effect on environmental optimization. The experimental design involved four treatments at the same fish density within the cage (Japanese flounder, , about 21 g/ind, 5 ind/cage) and different densities of (0, 50, 70 and 90 g; designated C, S1, S2 and S3). There were three replicates for each treatment. The cage was 60 cm in diameter by 30 cm deep. The fish and were starved for 24 h before being weighed. Five Japanese flounders and 20 g of were in the initial sample. All specimens were fed twice a day with artificial pellets at 07:30 and 18:00 during the experimental period. The amount of food was similar in each group and was adjusted according to the uneaten food in the control group. Uneaten food and fish feces were left in the system. The system had a steady flow rate of 250–300 L/day and light aeration was provided continuously. A simulated natural photoperiod (14:10, light/dark) was used throughout the experiments. At the end of the experiment, all animals were sampled, weighed after 24 h starvation, and oven-dried at 70 for 48 h for analysis. The results showed that the levels of carbon and nitrogen in the sediment were higher in the control (C) than in other treatments. There was no significant difference among treatments in the amount of carbon lost in respiration, or for the net output of organic carbon and nitrogen in water (> 0.05). The input of carbon and nitrogen was principally from food. In addition, there was no significant difference among treatments of the proportion of nitrogen for net output in water (> 0.05). The proportion of nitrogen output from the system was highest in the control, but there was no significant difference between C, S1 and S2 (> 0.05). The proportion of nitrogen accumulated in sediment was higher in the control than in either S2 or S3 (0.05). The proportion of carbon accumulated in sediment was highest in the control (0.05). The proportion of organic carbon for net output in water was higher in C and S1 than in S3 (0.05). The proportion of carbon output for the system was significantly lower in S3 than in S1 or the control (0.05). Both the carbon and nitrogen output ratios were lowest in the control. In the present experiment, was shown to be a significant consumer of uneaten food and feces in our model of “Japanese flounder cage culture and ”. Our novel model could be valuable in reducing carbon and nitrogen accumulation in the sediment beneath Japanese flounder cage culture and thereby improving the environment and enhancing fish production.

Abstract:) is one of the most important commercial freshwater species in China and, in recent years, its aquaculture has developed rapidly. However, with the expansion in cultivation scale, promiscuity and mixing between different populations has necessitated research on the genetic diversity of this species. A Japanese breed and Qingxi black mutant population are two new varieties of now found in China. Molecular research on these two new varieties is of great importance in the identification, germplasm protection and guidance of breeding studies on In this study, the 16S rRNA gene from 80 individuals of four populations (Yellow River, Japanese, Qingxi black mutant and Taiwan) of was amplified and sequenced for analyses of mutations, diversity parameters and s. A total of 53 mutation sites were detected in the studied gene including nine specific sites. A total of three specific sites were detected in the Qingxi black mutant population, one in the Japanese breed, one in the Yellow River population and four in the Taiwan population. The Qingxi black mutant population displayed the highest haplotype genetic diversity (0.821) followed by the Taiwan (0.484), Yellow River (0.195) and Japanese populations (0.100). The detected mutant sites added up to 16 haplotypes, including three in the Yellow River population, two in the Japanese, eight in the Qingxi black mutant and three in the Taiwan population. and genetic distance analyses showed a similar result in that the Yellow River and Qingxi black mutant population reflected a relatively closer relationship to the Japanese and Taiwan population, trees of haplotypes indicated that the four populations showed clear differentiation and can be identified effectively. The Japanese and Yellow River populations displayed a close relationship, indicating that the Japanese breed possibly originated in the Yellow River basin of China.

Abstract:Sessile organisms inhabiting the intertidal zones of rocky shores are exposed to constantly fluctuating and dramatic environmental changes on a daily basis. During low tide, they may be exposed to desiccation, hyper-or hypo-osmotic shock, extreme temperatures or prolonged light exposure, depending on season and latitude. The frequency and duration of these stresses increases with tidal elevation. Desiccation is the most important stress factor, and seaweeds that live in these zones are well adapted to significant water loss, displaying full physiological recovery during rehydration. Although the mechanisms of environmental tolerance in intertidal seaweeds are not completely understood, it has been suggested that reactive oxygen metabolism may play a key role. , a typical middle or high-intertidal species originally found in the south of China, is widely cultivated along the coasts of Fujian and Zhejiang Provinces. Owing to its high desiccation tolerance, simple morphology and ease of culture in the laboratory, is an ideal material for environmental adaption studies. In this study, we observed the physiological responses of blades of during desiccation stress. Reactive oxygen species (ROS), including superoxide anion free radical (, reduced glutathione (GSH) and ascorbate (ASA) content, were measured, as were the activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and ascorbate peroxidase (APX). The results show that an important boundary was reached at 60% water loss from the blades. When water loss was below 60%, the major constituent of ROS produced in the , which has a lower relative toxicity than the more toxic , which did not change significantly. The activity of APX and levels of ASA and GSH did not change significantly, while the activities of SOD, CAT and GR were significantly down-regulated. When water loss was below 60%, as the H₂O₂ content decreased, the levels of the more highly toxic were significantly increased and it became the major constituent of ROS in cells. Under these conditions, the activities of SOD, CAT and APX were still not significantly increased, while the activity of GR and levels of ASA and GSH were significantly up-regulated. These results suggest that GR, ASA and GSH play important roles in removing ROS during serious desiccation stress, while the antioxidant enzymes SOD, CAT and APX are not involved.