Abstract:. We cultured oocytes with mandibular organ (MO)as group 1, and oocytes with MO and X-organ-sinus gland (XO-SG) as group 2 . Oocytes cultured with medium were set as control. MO excretion promoted oocyte maturation by increasing the oocyte diameter at the 1^st, 3^rd, 6^th, and 14^th day after eyestalk ablation, particularly on the 6^th day (<0.01). Incubation with XO-SG significantly inhibited oocyte development (FAMeT expression. Levels were 265% higher than 6 and 14 days after eyestalk ablation, and were significantly higher than that in the control group (without MO) expression levels were lower on day 14 than that on day 6 and there was no change on day 1 and day 3 after eyestalk ablation>0.05). Our results suggest that the functional material in MO induces oocyte maturation, with the effect being strongest 6 days after eyestalk ablation. MO mRNA was downregulated by the XO-SG causing inhibition of oocyte maturation .

Abstract:We evaluated the combined effects of temperature and salinity on the energy metabolism of Nile tilapia juveniles (GIFT strain). We used a two-factor central composite experimental design (CCD) and response surface methodology (RSM) to test the effects of temperature (13–36excretion rate () under laboratory conditions. The linear effects of temperature and salinity, the quadraticsalinity, and the interaction between salinity and temperature had significant effect on ). The quadratic effect of temperature was not associated with changes in >0.05, <0.01), and could be used for prediction. The were influenced more by temperature than by salinity. At lowerOR, were higher around the iso-osmotic point. However, when salinity exceeded the iso-osmotic point, but vary with salinity ( and salinity range of 0–10, tilapia juveniles utilized protein-lipirespiratory quotient value was 0.752. Our results provide insight into the joint influence of temperature and salinity on the metabolism of tilapia juveniles and provides a bioenergetic basis for the study of how environmental factors govern the spatial and temporal pattern of energy distribution in this species.

Abstract:As in all other lower vertebrates, sex differentiation in fish is susceptible to environmental and steroidogenic stimulation or inhibition. Alteration of the sex differentiation process is possible in many fishes through the manipulation of the environment and steroid function. Some chemicals, which have androgenic or estrogenic function, are known to alter the gonadal sex in fish from female to male or vice versa if administered during the period of gonadal sex differentiation. Other than direct androgenic or estrogenic effects, there are chemicals which are capable of disrupting the enzymatic pathway of natural androgenic-estrogenic balance in fish. Among the non-steroidal aromatase inhibitors (AI), letrozole is typically used as an effective human drug in the treatment of estrogen-dependent disease, including breast cancer, and was found to be effective in suppression of all estrogens after oral administration. )]. Gonadal development was observed histologically using a microscope, and the expression of CYP19A and CYP19A was expressed in female, and A quantitative real-time PCR analysis revealed that the expression of the gene in female was significantly inhibited after treatment with LE. Though expression of was higher at 22 days post hatch (dph) than at 9 dph, it was only 2.11 the level of the control female. gene expression was up-regulated gradually in LE treated female fry during sex differentiation, and reached the same level as control males at 150 dph. In LE treated female fry, degeneration of the ovarian cavity and primary spermatocytes were observed in sections of the gonad. The functional testes were developed at 150 dph. Our research demonstrates that aromatase activity is necessary for ovarian formation and development during sex differentiation in T. obscures during sex differentiation.

Abstract:We evaluated the genetic variation and genetic structure of northern largemouth bass(N), Florida largemouth bass, (F), and their obverse (N♀×F♂) and inverse (F♀×N♂) crosses, using 18 pairs of microsatellite primers. We generated between 2–8 alleles at each locus, with a mean allele number of 5.0. Six subspecies specific loci (Jzl48, ) could be used to distinguish parents and their reciprocal hybrids. The number of effect alleles (), and polymorphic information content were all highest in F♀×N♂ (3.199 70.570 6, respectively). The observed heterozygosity ( analysis of all groups and loci revealed that both reciprocal hybrids had lower genetic differentiation with N species. The UPGMA clustering analysis suggested that the offspring was nearest to the female brood stock for the obverse cross and nearest to the male brood stock for the inverse cross, suggesting that northern largemouth bass pass more genetic material than Florida largemouth bass.

Abstract:Cold-water fish culture first began in China in 1959 with a shipment of eyed eggs and fry of rainbow trout from the Democratic People's Republic of Korea. Since then, rainbow trout culture has expanded rapidly into more than 22 provinces. However, further advances depend on accelerating the process of selective breeding and preventing the genetic degeneration of this species. We evaluated the utility of PIT marker assisted selection using a generation one (G1) of a rainbow trout superior strain population which was being selectively bred by the Heilongjiang River Fishery Research Institute (HRFRI) of the Chinese Academy of Fishery Sciences (CAFS). We developed 72 rainbow trout families using PIT marker assisted technology. All pedigreed fry were implanted with PIT markers and cultured in the same pond. Body weight and body length were measured for all the market size rainbow trout individuals 850 days after fertilization to screen for rapid growth families. The family effect was highly significantly for both body weight and body length (<0.01). We obtained 8 rapid-growth families in which the family effects for body weight and body length were both significant (<0.05). The family numbers were 682BABB, 6717B7A, 6828308, 682A50A, 6829C24, 6829DC7, 682A382, and 68284DA. Our results may be compared with our previous work based on BLUP analysis of individual estimated breeding values. Our study provides insight into methods for improving the accuracy of genetic selection for growth traits in rainbow trout, and for genetics and breeding research into quantitative traits in other aquatic animals.

Abstract:Morphological characteristics and elemental fingerprints were compared in Chinese mitten crabs () from three lakes (Taihu Lake, Shijiu Lake and Gucheng Lake) in Jiangsu Province. Truss network analysis using 16 length measurements suggested that crabs from the three lakes could not be characterized based on morphological characteristics. The accuracy rates yielded by discriminant analysis were 70% for crabs from Taihu Lake, 90% for those from Shijiu Lake, and 80% for those from Gucheng Lake. An Agilent 7500ce ICP-MS was used to of 21 chemical elements (Na, K, Ca, Fe, Mg, Sr, Ag, Al, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Tl and Zn) in the third pereiopod of the crabs from the three lakes. The concentrations of Cr, Co, As, Se, Cd, Pb, Tl, Ag, Mo, and Ni were below the detection limit. However, in contrast to the morphological analysis, the origin of the crabs from the three lakes could be consistently identified from their elemental fingerprints. The corresponding accuracy rates yielded by discriminant analysis were 100% for crabs from Taihu Lake, 80% for those from Shijiu Lake, and 100% for those from Gucheng Lake. We conclude that the approach of using environmentally determined elemental fingerprints in the third pereiopod of the crabs is a potentially valid method for identifying the

Abstract:) has declined since the 1970s. Despite the decline, little is known about the Our objective was to document the dietary composition of large yellow croaker. We collected 579 specimens from the sea near Guanjing Yang, Fujian province during June 2010. We documented the stomach contents of each individual and calculated the occurrence frequency (%), and an index of relative importance (IRI). In addition, we compared diet composition of the zooplankton and nektonic assemblages in the ambient water. We identified 32 species in the diet. The most abundant were decapoda, fish, amphipoda, crabs, copepoda, and stomatopoda. Decapoda (%IRI=49.14%) and fish (%IRI=20.47%) were the most important prey groups in the diet. %IRI=2.34%) constituted the second most important prey groups. were the most important prey species. Our data suggest that the large yellow croaker is carnivorous and feeds primarily on decapods, fish, and macro zooplankton. The trophic level of the wild large yellow croaker is lower than nektonic-animal feeders but higher than planktonic-animal feeders. The dominant species of the zooplankton assemblage was copepoda, primarily =0.06). The percent mean abundance of was 0.83%. Fish, crabs, and decapods were the most abundant nektonic organisms. exhibits selectivity for food, preferring small decapods, fish larvae,

Abstract:We evaluated the trophic ecology of fish on the Xuwen Coral reef. We collected samples of representative species and quantified levels of δ¹³C and δ¹⁵N. There was significant variation in the δ¹³C and δ¹⁵N values. δ¹³C ranged from –20.98 and δ¹⁵N ranged from 11.66. The levels of δ¹³C and δ¹⁵N were generally higher than in fish from other regions. We estimated the trophic level based on the δ¹⁵N values. The majority of fish species in the Xuwen Coral Reef were lower and mid-level carnivores. The remainder were omnivores and higher carnivores. Among all fish species, more than half were lower carnivores (70 species, 52% of the total species). The mid-level carnivores (47 species) accounted for 35% of the total species. The omnivores (11 species) and higher carnivores (8 species) accounted for 8 and 5%, respectively, of the total species count. We compared these results to those of gut-contents analysis for 54 species. For the majority of species (85%), the trophic level estimated by the two methods differed by less than 0.5 units. Thus, stable isotope analysis provides a rapid, reliable method for documenting ocean food webs.

Abstract:We evaluated the relationship between environmental indices and succession in the algal communities of artificial reefs near Lidao, Rongcheng. We documented species diversity and biomass on a quarterly basis between August 2009 and August 2010, about 3 years after the reefs were installed. We documented thirteen algal species belonging to three divisions. Of these, six species belonging to Rhodophyta dominated the flora numerically. Conversely, Phaeophyta had the highest biomass density (92.724 g/m²) The algal community had reached maturity after three years of development. The number of species and biomass were higher in summer and autumn than in spring and winter. Both cluster analysis and detrending correspondence analysis revealed 83.1% similarity between algal communities in rock reefs and natural reefs. Both the biomass and diversity index were higher in algal communities in rock and natural reefs than in concrete reefs. PCA and DCA analysis suggested that temperature was the major environmental factor affecting the algal communities, explaining 47.6% of the variation. Nitrogen and phosphorus constituted secondary factors in the natural reef area whereas pH and dissolved oxygen (DO) levels were secondary in artificial reef areas.

Abstract:We evaluated the chronic toxicity of zinc sulphate in the crayfish 2+ for 21 days. Each day, we randomly selected five crayfish in each group and collected samples of the hepatopancreas, gill, and muscle tissue from males and females and ovarian tissue from each female. The tissues were placed in Bouin’s fixative for 24 h,rick red particles in the hepatopancreasantennal gland in animals exposed to . The number of these particles was positivelyand exposure time. There was no obvious . We observed bleeding and necrosis in hepatopancreas, antennal gland, and gills in the group exposed to 4.04 mg/L after 7 d. The proportion of necrotic cells increased as the concentration of Zn²⁺ and time of exposure increased. We observed spermatocyte necrosis after 14 d in exposure to 40.37 mg/L Zn²⁺. After 21 d, we observed bleeding of the spermary and ovary and necrosis of the ootid and spermatocyte cells. A large number of hepatocytes exhibited necrosis and had dropped from the hepatic ducts. The connective tissue exhibited hyperplasia, with large numbers of cells blocking the hepatic ducts, resulting in in the hapatopancreas of the group exposed to pathological changes in the hepatopancreas, antennal gland, gills, and gonad tissue of . Given that zinc sulphate interferes with the metabolic, respiratory, and reproductive systems, chronic exposure is likely to threaten the survival of

Abstract:Two pairs of specific primers were designed based on the grass carp reovirus (GCRV) VP6 coding gene sequence. Using GCRV genomic total RNA as a template, we developed a reverse transcription-loop mediated isothermal amplification (RT-LAMP) assay. After optimizing the reaction conditions, we were able to successfully amplify the targeted GCRV VP6 coding gene at 63 in 1 h. Analysis of the amplified products by agarose electrophoresis revealed that the band pattern resembled that of the ladder diagram in a gel. After adding SYBR Green I fluorescent dye to the reaction system, the green positive amplification could be viewed by eye. Our assay was highly sensitive to grass carp reovirus with a lower detection limit of 33 pg, which was 10-fold higher than that of traditional RT-PCR for GCRV. Moreover, the assay was specific for the detection of GCRV and was not susceptible to cross reaction with other viruses, including Channel catfish reovirus (CCRV), Spring viremia of carp virus (SVCV), Koi herpesvirus (KHV), and giant salamander iridovirus (GSIV). In conclusion, the RT-LAMP assay is convenient, rapid, sensitive, and specific for GCRV detection. Our assay provides a novel approach for the detection of GCRV and the diagnosis of grass carp hemorrhage.

Abstract:We evaluated the effects of suspended solids on the survival and physiology of the Kumamoto oyster, . The oysters were exposed to 0, 50, 100, 500, 1 000, or 5 000 suspended solids (SS) for 15 d then returned to clean seawater, without SS, for 15 d. We monitored survival and measured -ATPase, SOD, CAT, and DNA damage in the gills and the RNA/DNA ratio in the muscle tissue+-ATPase, were significantly lower in the groups exposed to SS after 15 d. Furthermore, there were obvious signs of DNA damage in these groups. We observed some recovery in these indices following transfer to clean seawater. However, recovery was incomplete and levels did not return to those of the controls. Our results suggest that these physiological and biochemical indices may be more sensitive than survival as indicators of exposure to increased SS in .

Abstract:yeast to complexes with thallus and extracellular bacterial . We investigated the effects of the antigen complexes on the cellular immune response of tilapia by. In addition, tHsp70 alone and its complexes significantly stimulated growth and attachment of peritoneal macrophages and enhanced of peritoneal macrophages.treatment with and led to cell death, while reduced the cell death. tHsp70 alone or tHsp70-antigen complexes significantly increased the expression of immune related genes () in tilapia peritoneal macrophages compared to antigen only and control groups. Our results suggest that tHsp70 has an immunoadjuvant and immunopotentiator function, and provides experimental data for development of a

Abstract:Cytochrome P450s (CYPs) widely distribute in the liver of aquatic organisms and play a key role in drug metabolism. CYPs catalyze the N-deethylation of (CIP). However, there is limited information regarding the action of CYPs in fish. We evaluated the of baicalin (100 mg/kg). We measured the enzymatic activity of cytochrome P450 1A (CYP1A) and 3A (CYP3A) in liver microsomes. In addition, we documented the pharmacokinetics of decreased significantly over time and both CL inceased after oral administrated of elimination was accelerated. The was 1.48% and 2.22% for the BL and GZ groups, respectively (control: 0.95%). The AUC_{was 2.16% and 1.76% for the BL and GZ groups, respectively (control: 1.7%). Thus, BL and GZ contributed to induce N-deethylation of . Pretreatment with significant erythromycin-N-demethylation (ERND) activity, the specific probes for CYP1A and CYP3A, BL and GZ accelerated the elimination of metabolite was related to the induction of CYP1A and CYP3A enzymatic activity.}

Abstract:infects a number of cultured fish species, causing heavy economic loss in Guangdong province. We evaluated the prevalence of infection with in tilapia ( ( ( using a standard microbiological assay and specific PCR. Using PCR, we detected in all three species (30.21%, 23.53%, and 14.55% of individuals, respectively). However, was only isolated from using the traditional microbiological assay. was detected in all tissues, includingmuscle were more susceptible to than the other tissues in tilapia (infection rate: 20.65%bass (infection rate: 12.1% , respectively). There was no difference in the susceptibility of the tissues in . Moreover, our results suggested that body length was inversely correlated with the infection rate by

Abstract:tissue quality during freezing and thawing processes. Silver carp is one of the primary freshwater fish species in China. With high nutritional values, fast growth rate, and high yield, this species forms the basis of an important industry. Because of the negative effects associated with microbiological growth and biochemical processes, frozen storage is widely used to preserve fish and fish products. However, the melting and reformation of ice crystals causes osmotic removal of water, mechanical damage, and denaturation of proteins. The extent of the loss in tissue quality is dependant on the rate of freezing, thawing methods, storage temperature and temperature fluctuations during storage, transportation, retail display, and consumption. Repeated freezing and thawing processes are common in storage and at retail outlets, in homes, and restaurants. Despite this, the effects of freezing/thawing on changes of color, muscle texture and protein physicochemistry have not been fully investigated. We stored fresh silver carp at C for 10 days. After being thawed by flowing water, the thawed carp were refrozen at the same temperature for another 5 days. This freeze-thaw cycle was repeated five times. After the first, third, and fifth cycles, we randomly selected three silver carp and measured changes in thawing loss, cooking loss, hardness, chewiness, resilience, thiobarbituric acid (TBA), L* value, b* value, salt soluble protein (SSP) content, Ca²⁺-ATPase activity, total sulfhydryl groups (SH) content, surface hydrophobicity, and sensory scores. During the first freeze-thaw cycle, hardness, chewiness, resilience, salt soluble protein (SSP) content, and Ca²⁺-ATPase activity whereas b* and surface hydrophobicity <0.05). After the third freeze-thaw cycle, thawing loss, L*, and TBA levels significantly increased (after the fifth freeze-thaw cycle. In contrast, there was no significant change (>0.05) in cooking loss following five freeze-thaw cycles. After the fifth freeze-thaw cycle, the sensory scores were 47, which were unacceptable. Our results confirm that the freeze-thaw process causes thawing loss, discoloration, softening of muscle tissue, lipid oxidation, decrease in SSP content, and protein conformational changes. These changes have a detrimental effect on the quality of silver carp tissue. So it is important to prevent fluctuation of temperature during storage, transportation, and retail to avoid the negative effects of freeze–thaw cycles on silver carp tissue quality.

Abstract:) is an important marine flatfish with significant potential for in China. This species exhibits a typical sexual dimorphism in which males grow significantly slower and smaller than females. Thus, there is little economic benefit to culturing males. To improve our understanding of this sex-associated dimorphic growth phenomenon, we screened differentially expressed genes from the pituitary tissues of female and male half-smooth tongue sole using the Affymetrix zebrafishmicroarray. d. Based on standards for the relative strength of the difference (i.e., a ratio of the male to female hybridization signals of >1.5 or <0.6), we identifed 39 differentially expressed genes, including col1a2, slc25a5, . Our results provide a foundation for investigating the molecular mechanisms controlling differential growth among the sexes.

Abstract:juveniles. The results of acute toxicity test showed that the median 96 h lethal concentration (LC₅₀) for Cu²⁺ was 309.74 μg/L. We also measured catalase (CAT) and superoxide dismutase (SOD) activity and malondialdehyde (MDA) content in the soft tissue of clams exposed to 10, 30, or 40 μg/L Cu²⁺, respectively, at 6,12, 24, 48, 72 and 96 h of exposure. CAT activity of the maximum exposed group was lower after 48 h relative to the controls whereas both CAT and SOD activity of all exposure groups were higher at 6, 24, 72 and 96 h. The MDA content was higher in fish exposed to Cu²⁺ than in the control group after 96 h. Our results suggest that exposure to Cu²⁺ causes oxidative damage in juveniles.