Abstract:Body weight and standard length traits are complex and important economic traits, and are also targets for selective animal breeding. Our objective was to identify QTL associated with body weight (BW) and standard length (SL) traits. We conducted a whole genome scan on 190 progeny from a full-sib family using 940 microsatellite markers. We conducted half-sib mapping using GridQTL software. We obtained 8 QTL distributed across 5 linkage groups (LG) during sire-based QTL analysis. For BW, 5 QTL were identified, of which 1 QTL occurred at the 95% genome-wide level, and was located at LG26. The remaining 4 QTL were at the 95% chromosome-wide level, explaining 12.5%–32.6% of phenotypic variance. For SL, 3 QTL overlapped with the BW QTL intervals. One QTL was identified at the 99% genome-wide level, and 2 QTL were at the 95% chromosome-wide level, explaining 18.4%–40.9% of phenotypic variance. During dam-based QTL analysis, we identified 11 QTL that were distributed across 7 LGs. Six QTL were associated with BW, of which one was at the 99% genome-wide level and was also located at LG26. Two QTL were identified at the 99% chromosome-wide level, leaving 3 QTL at the 95% chromosome-wide level, accounting for 15.7%–37.6% of phenotypic variance. For SL, 5 QTL were identified, of which 4 were the same marker or had a similar confidence interval with BW. Among these, 1 QTL was identified at the 99% genome-wide level, 1 QTL was at the 99% chromosome-wide level, and 3 QTL were at the 95% chromosome-wide level, explaining 16.7%–39.5% of phenotypic variance. Our results suggest that the most significant QTL maps to LG26 and is significant at the genome-wide level in both the sire and the dam-based analyses. The minimum confidence interval was only 3 cM, which can in mirror carp. Our results provide a useful reference for further candidate gene research and MAS in mirror carp.

Abstract:) is an important cultured marine fish species in northern China. Females grow three to four times faster than males. The low growth rate of males leads to an overall reduction in production, thus reducing their value. Given this, the development of all-triploid stocks would be a significant benefit to the commercial aquaculture of half-smooth tongue sole. We developed a method for in this species. The optimal initiation time for pressure shock of fertilized eggs was 21.5 min after fertilization at 23C. The optimal pressure and treatment duration were 40 MPa and 4.5 min, yielding a tetraploid rate in fry of 68.3%. We analyzed the ptetraploid DNA relative content was two times that of chromosomes in triploid fry, whereas normal diploid fry have 42 chromosomes. Our method provides

Abstract:, is widely distributed throughout China, Japan, Korea, and Burma. This species is of economic importance in China where about 209 000 t are produced annually by intensive culture. However, the economic value of the species has declined significantly in recent years due to genetic retrogression. To facilitate genetic improvements, we constructed a genetic linkage map for oriental river prawn using SRAP and SSR markers and pseudo-testcross mapping.A total of 175 makers including 27 microsatellite and 148 SRAP makers were mapped in 53 linkage groups. The number of markers per group ranged from 2 to 8 and thirty-five groups included no less than three markers. The average number of markers per group was 3.3. The length of groups ranged from 6.7 cM to 91.2 cM (Kosambi). The maximum space between adjacent markers was 49.0 cM while the minimum space was 1.4 cM, with an average distance between markers of 13.1 cM. The framework map contained 16 groups with a length of 997.2 cM. The total length of the map was 2 270.5 cM. The average estimated genome size for oriental river prawn was 4 380.6 cM. Based on the estimated genome lengths, the map accounted for 51.83% of the genome. This is the first genetic linkage map of oriental river prawn. Our data may be used to aid quantitative trait loci (QTL) mapping, gene cloning, and genetic selection. The map also provides a basis for the construction of a higher density genetic linkage map for oriental river prawn.

Abstract:agglutinative and hemolytic properties. We used affinity chromatograph, SDS-PAGE, far-western-blotting, MALDI-TOF/MS, and bioinformatics to determine the target of hemocyanin binding. Hemocyanin bound specifically to an ~The protein shared high homology withhrimp hemocyanin bound to human thioredoxin peroxide following the “lock - key model” at the tertiary structure level. Together, our data suggest that thioredoxin peroxide mediates, at least in part, the interaction between erythrocytes and shrimp hemocyaninagglutination and hemolysis

Abstract:We evaluated the effect of salinity on the metabolism of female Chinese crabs (). The crabs, body weight (55.59 ± 6.24) g, were held at salinities of 0, 6, 12, 18 and 24, (16 ± 1) production, and ammonia-N excretion. Using this data, we calculated the respiratory quotient, oxygen-nitrogen ratio, energy consumption rate, and metabolic substrate ratio. Salinity had a significant effect on the oxygen consumption rate and ammonia–N excretion rate (<0.05). Between salinity 0–24, the rates of oxygen consumption and ammonia–N excretion both decreased as salinity increased. We observed a similar pattern for CO₂ production and energy consumption, but the differences were not significant relative to the control group at salinity 6 >0.05). Between salinity 12–24, CO₂ production and energy consumption were significantly lower than in the control group. Salinity had no effect on the respiratory quotient and oxygen–nitrogen ratio . Our results suggest that lipids are used preferentially as an energy source. Furthermore, proteins were utilized to a much greater extent than carbohydrates. The proportion of lipids in the metabolic substrate increased as salinity increased. Conversely, the carbohydrate metabolic substrate ratio decreased as salinity increasedwhereas the protein metabolic substrate ratio remained constant. At salinity 24, the ratio of protein, carbohydrate, and lipid used as metabolic substrate was 6.479.0. During the reproductive migration, the female Chinese crab migrates from fresh water into the Yangtze River estuary. Thus, individuals must adjust to the higher salinity and modify their energy metabolism. Our results suggest that energy consumption decreases after entering salt water, allowing female crabs to divert energy into reproduction.

Abstract:We investigated the relationship between the eyed rate and the biochemical composition of eggs and ovarian fluid in , amino acids, vitamins, and minerals in stage V eggs and ovarian fluid. We used each of these parameters as an independent variable in a regression model to predict the eyed rateATPase activity, phosphorus levels, and amino acids in the eggs. There was no correlation between the eyed rate and the remaining parameters (protein, , succinate dehydrogenase, calcium ions, iron ions, vitamin C, and vitamin E). Egg batches with high viability (μmolPi/(min·mgprot), levels of phosphorus between 12.97 and 23.03 μmol/g egg, and levels of amino acids between 574.89 and 1 195.40 μmol/g egg. In contrast, in the ovarian fluid only Egg batches with high viability (spartate aminotransferase activity >18.14 μmol/min/L ovarian fluid.

Abstract:in the Guishi reservoir Guangxi Province using scales, opercula, and anal-fin spines. We collected 688 specimens between September 2008 to August 2009. The interpretation of age based on scale readings was reliable. Annual rings were formed primarily by the pattern of sparseness-denseness and the cut of the scales. The pattern of sparseness-denseness was visible in the prezone region whereas the cut pattern was present on the rear-side region. Annuli formation took place primarily between April and June each year, likely related to the timing of reproduction. The estimated ages ranged between 0 and 4 years old, but were dominated by the younger age classes (age 0 and 1). The body-length of specimens ranged from 11.25 to 40.50 cm, with the majority (70.49%) being 15–21 cm. Body weight ranged from 29.1 to 2 257.8 g, but most fish (62.12%) were between 100–300 g. The body length-scale radius relationship was 9, =623) therefore, was considered to be isometric. The growth equations for body length and weight were 3.087 6, respectively. The inflexion age on the growth rate curve for weight was 3.93, and corresponded to a body-length of 39.89 cm and weight of 1 554.81g. Our data suggest thatpopulation had been overexploited. To protect the population and allow for sustainable utilization, we suggest only fish greater than 990 g (age 3) should be harvested.

Abstract:in the Guishi reservoir Guangxi Province using scales, opercula, and anal-fin spines. We collected 688 specimens between September 2008 to August 2009. The interpretation of age based on scale readings was reliable. Annual rings were formed primarily by the pattern of sparseness-denseness and the cut of the scales. The pattern of sparseness-denseness was visible in the prezone region whereas the cut pattern was present on the rear-side region. Annuli formation took place primarily between April and June each year, likely related to the timing of reproduction. The estimated ages ranged between 0 and 4 years old, but were dominated by the younger age classes (age 0 and 1). The body-length of specimens ranged from 11.25 to 40.50 cm, with the majority (70.49%) being 15–21 cm. Body weight ranged from 29.1 to 2 257.8 g, but most fish (62.12%) were between 100–300 g. The body length-scale radius relationship was 9, =623) therefore, was considered to be isometric. The growth equations for body length and weight were 3.087 6, respectively. The inflexion age on the growth rate curve for weight was 3.93, and corresponded to a body-length of 39.89 cm and weight of 1 554.81g. Our data suggest thatpopulation had been overexploited. To protect the population and allow for sustainable utilization, we suggest only fish greater than 990 g (age 3) should be harvested.

Abstract:We evaluated the effects of salinity on the growth, molt, and energy utilization of juvenile The crabs were held at five salinities (15, 20, 25, 30, and 35) and cultured in rectangular aquariums. Each treatment group was quadruplicated, with each replicate consisting of 3 stages (7 juveniles/stage). During the 50-day experiment, mortalities and incidence of “molt death syndrome” were recorded daily, while the intermolt period, carapace length, carapace width, and wet weight were measured at each molt. Salinity had a significant effect on growth and energy utilization. At salinities of 20, 25, and 30, food intake (FI_d) was lower and food conversion efficiency (FCE_d) was higher than in the control. At 30, FCE_d was significantly higher than in crabs held at 15 and 35, but not different from those held at 20 and 25. The assimilation efficiency ) of crabs held at 20, 25, and 30 were significantly higher than in the remaining groups. At the end of the experiment, crabs held at 25 and 30 had a higher wet body weight, relative body weight gain, and SGR. The difference was significant when compared to crabs held at 15 and 35 ppt, but not 20 and 25 ppt. Regression analysis suggested that maximum would occur at salinity 26.3. The molt recycle (MC) between instars 18.9 to 23.5 d, and was not different among the groups. Nevertheless, was 3.1−4.6 d shorter in crabs held at 30 than the remaining groups. MDS was observed at 15, suggesting that the lower salinity plays a role in inhabiting the molt of . Conversely, new shell hardening was inhibited by higher salinity. Our results indicate that the culture water should be maintained at about 25 salinity to improve growth and molt success.

Abstract:We evaluated the effects of fishmeal substitution with alfalfa protein concentrate on growth, body composition, and blood biochemistry in juvenile starry flounder. We formulated six isonitrogenous and isoenergetic diets, in which fishmeal protein was replaced by alfalfa protein concentrate in the following proportions: 0% (S0), 10% (S10), 20% (S20), 30% (S30), 40% (S40), 50% (S50). Specific growth rate (SGR), daily feed intake (DFI), feed efficiency (FE) and protein efficiency ratio (PER) were unchanged in fish fed S0, S10 or S20, but were significantly lower in fish fed S30, S40, or S50 (<0.05). The condition factor (CF) was lower and the digestive tract index (DTI) was higher in fish supplemented with alfalfa protein concentrate (<0.05). The apparent digestibility of dry matter, protein, and lipid were all linearly decreased by the addition of alfalfa protein concentrate (<0.05). Broken line analysis based on SGR . The levels of muscle lipid were significantly lower in fish fed S40 than those fed diets S0 and S20, while there was no obvious effect on the other proximate constituents. Liver moisture increased significantly in fish fed diets S0, S10, and S20, and then leveled off in fish fed diets S30, S40, and S50. The reverse was true for liver lipid content. Crude protein was significantly higher in the liver of fish fed diets S30 and S50 than in fish fed S0. Liver crude ash content was not affected by fishmeal replacement. The whole fish moisture content was increased whereas crude lipid content was decreased by dietary fishmeal substitution with alfalfa protein concentrate . Whole fish crude protein content was highest in fish fed S30 and lowest in fish fed S40. There was no change in whole fish crude ash content . Triglycerides were significantly reduced by replacement of >20% fishmeal. Cholesterol content and (LSZ) activity were both linearly decreased by alfalfa protein concentrate supplementationphosphate (ALP) . AST and ALT activities were enhanced by experimental diets with a replacement ratio of >20% and >40%, respectively. There was no difference in (MDA) content in fish fed diets S10 to S50, which were lower than fish fed diet S0 (SOD) activity and the fishmeal replacement ratio. In summary, our results suggest that alfalfa protein concentrate can replace up to 19.0% fishmeal protein in the diets of

Abstract:JI Tilapia is a new hybrid and salt tolerant species developed for culture and published in the 1 339th announcement of Agriculture Ministry of China in February 2010. We investigated the dynamics of total particular matter (TPM) and particular organic matter (POM) in 3 shrimp-tilapia poly-culture ponds (406, 407, and 408) in Dianbai, Maoming City, Guangdong province between August and October, 2010. In addition, we evaluated the effects of POM on the growth and survival of tilapia. The concentration of TPM ranged between 35.0 and 153.8 mg/L, (83.1±34.1) mg/L. The concentration of particular inorganic matter (PIM) ranged between 19.0 and 54.0 mg/L, (34.3±11.8) mg/Land constituted 41.28% of TPM. The dry weight of plankton (PZ) ranged between 2.43 and 22.48 mg/L, (9.63±5.91) mg/L, and constituted 11.59% of TPM. The dry weight of phytoplankton (DWP) ranged from 2.298 to 22.105 mg/L, (8.99±5.98) mg/L, and constituted 10.81% of TPM. The dry weight of zooplankton (DWZ) ranged from 0.018 to 2.724 mg/L, (0.65±0.61) mg/L, and constituted 0.78% of TPM. Particular debris and bacteria ranged from 14.339 to 97.958 mg/L, (38.97±25.53) mg/L, and accounted for 81.77% of POM. weight gain and specific growth tilapia cultivated in the cages within Pond 407 than in the other two ponds. However, there were no significant differences in tilapia survival among the three ponds.

Abstract:We evaluated the effects of replacing fish meal with housefly maggot meal (HMM) on the nutritional composition, amino acids, and inosine monophosphate content in the muscle of juvenile white shrimp (). Six isonitrogenous and isoenergetic diets (G0, G20, G40, G60, G80, and G100) were formulated by replacing 0, 20%, 40%, 60%, 80%, or 100%, respectively, of the fish meal with HMM (protein basis). The shrimp initial body weight (0.56±0.03) g, were fed the experimental diets for 45 d. There was a positive correlation between crude protein and ash content in the muscle and the proportion HMM in the diet. The crude protein content in G100 and the ash content in G80 and G100 were significantly higher than in the control group (0.05). Similarly, there was no difference in free delicious amino acid (DAA) content () and total free DAA among the groups. Total free essential amino acid (FEAA) content was significantly higher in groups G40 to G100 than in G0 (0.05). Increasing amounts of HMM were associated with a significant increase in free arginine content (0.05). The total free amino acid content was significantly higher in G20, but not in G40>0.05). The inclusion of HMM only had an effect on inosine monophosphate (IMP) content at the highest level (G100: 0.05). There was no significant difference in the content of combined DAA (aspartate, glutamate, glycine, alanine), EAA, or total amino acids in the muscle of groups fed HMM compared to the control (0.05). Overall, inclusion of HMM had no significant effect on the nutritional composition, EAA, DAA, and IMP content in the muscle, with the exception that the free arginine content increased significantly when HMM was substituted at levels below 60%.

Abstract:Little is known about the biogenetics of gastropods. To address this, we measured the standard metabolic rate (SMR) of at different water temperatures, salinities, and time regimes. We measured SMR every 6 h using the bottle-incubation method. Individuals were incubated at six temperatures (from 10 to 35 consumption rate, ammonia excretion rate, and CO₂ emission rate of the two gastropods were significantly affected by water temperature (B. aeruginosa varied significantly with changes in temperature and salinity, causing changes in enzyme activity. We calculated the consumption rate, ammonia excretion rate, and CO₂ emission rate. These indices can be used to indicate energy sources and provide insight into how individuals cope with environmental changes. The ratio of O:N and the respiratory quotient, indicators of protein consumption, were lowest at 25°C suggesting this is the optimal temperature for values suggest that to changes in temperature. Increases in salinity were associated with an increase in metabolism (e.g., O₂ consumption and CO₂ emission) due to the extra energy required for regulation of ionic equilibrium. The reduced sensitivity towards changes in temperature suggests that these gastropods are minimizing energy consumption during changes in temperature, thus preserving energy for ionic homeostasis. The metabolic activity of , was significantly affected by the interaction between temperature and salinity. The metabolic rate of both gastropods fluctuated diurnally, being higher during the night. This likely reflects the diurnal pattern of activity in both species, which tend to feed and compete for dissolved O₂ during the night.

Abstract:We evaluated the individual and joint toxicity of zinc and cadmium during the early embryonic development of the zebrafish (2+ and Cd²⁺ 24 h post-fertilization (24 hpf). We monitored the number of embryonic coagulated eggs and the rhythm of the heart at 48 hpf and the number of embryonic coagulated eggs, hatching rate, and malfomation rate at 72 hpf. The effects of Zn²⁺ and Cd²⁺ differed among the stages of development. In general, Zn²⁺ was more toxic than Cd²⁺. The embryos were most sensitive to Zn²⁺ and Cd²⁺ toxicity at 72 hpf. Regardless of the ratio of Zn²⁺ and Cd²⁺ during joint exposure (11), the two chemicals tended to act synergistically. However, the joint toxicity was defendant on the endpoints and the ratio of each metal. For example, at equal concentrations of Zn²⁺ and Cd²⁺ (1the effect was synergistic at 48 hpf but antagonistic at 72 hpf. Furthermore, at a ratio of 2) the effect on egg coagulation was synergistic whereas the effect on the rate of hatching was antagonistic. Thus, our results suggest that joint toxicity is affected by both the concentration of each chemical and the exposure time.

Abstract:Effects of BDE-47 on gene expression levels of AhR, CYP4, GST-pi and Pgp of the gills and digestive glands of clam were studied in a 21-day exposure test. The results showed that the no significant change in the control clams during the exposure. AhR mRNA expression levels reached maximum and minimum at day 6 and day 1. mRNA gene expressionreached the peak value at . GST-pi mRNA expression levels in 0.25 µg/L BDE-47 group are significantly higher than control levels, while in 6.25µg/L BDE-47 treatments are significantly lower than Pgp mRNA expression levels in all BDE-47 treatment groups are significantly higher than Significant dose and time-dependent relationship between the expression levels of GST-pi mRNA and BDE-47 exposure doses were found in the results, indicating that GST-pi mRNA expression in the gills and digestive glands of can be considered as a potential biomarker which can be used to evaluate BDE-47 pollution in seawater.

Abstract:The commercial culture of shrimp has expanded rapidly in China in recent decades and is now one of the most important agricultural industries. However, shrimp production decreased significantly between 1992−1997 due to the outbreak of white spot syndrome (WSS). WSS is of serious concern to shrimp farming throughout the world as mortality can approach 100% within 3−10 d of infection with WSSV. There is currently no effective treatment for this disease. We measured the variation in infection intensity of WSSV carried by shrimp (Litopenaeus vannamei) among six ponds in Hongtai Farm in Shanwei of GuangDong province between July and November 2010. In addition, we measured several environmental indices, water quality indicators, and the population structure of planktonic algae. We used real-time PCR to quantify the number WSSV copies in each shrimp. All the shrimp larvae carried WSSV at concentrations ranging from 1.3×103 to 1.7×104 copies/g. Furthermore, the shrimp were infected with WSSV throughout the entire farming period. The mean number of WSSV copies was higher in the gill tissue (2.3×109 copies/g) than in the muscle tissue (3.2×108 copy/g), but the difference was not significant (P>0.05). The number of WSSV copies tended to increase in both tissues throughout the farming period, and was characterized by a number of peaks. During the early rearing period, the number of copies ranged from 1.3×103–3×107copies/g, whereas in the mid and latter stages of rearing the number of copies increased to 1.5×106−1.2×1011 copies/g. In some ponds, outbreaks of WSS forced an end to farming. Rapid changes in water temperature, algae population structure, and weather were also associated with changes in the number of WSSV copies in shrimp. Our results suggest that shrimp can be cultured even when infected with WSSV. The intensity of infection with WSSV varied temporally and was affected by culture time and envi-ronmental factors. We suggest that maintaining the population structure of planktonic algae, keeping water quality constant, and decreasing stress can significantly reduce the likelihood of WSS outbreak.

Abstract:It was formerly believed that there were 3 populations of Larimichthys crocea distributed in the China Sea. Among these, individuals in the waters of Daiquyang, Zhejiang province and Guanjingyang were thought to belong to different populations. We reviewed the delineation of populations of L. crocea in the East China Sea and Yellow Sea based on a suite of methodologies, including geographical isolation, population dynamics, and ocean hydrology, so as to provide a rigorous basis for the division and to improve our ability to track declines in a given population. We used catch statistics of L. crocea from 1971 to 1982 from several major fishing companies. We identified two over-wintering grounds in the northern offshore and the southern near-shore regions of the East China Sea. The over-wintering resources in the Mindong-Wentai fishing grounds played a dominant role in the southern near-shore region of the East China Sea. The Guanjingyang L. crocea population overwintered in the waters of Mindong. Given this, the Guanjingyang L. crocea population was assigned to the East China Sea & Yellow Sea population. Two additional lines of evidence support this assignment. First, during a mark recapture study, a male large yellow croaker that was tagged at Daiquyang on May 20, 1958 was caught in Lianjiang (26°21′5″N, 119°50′E, 32 meters) on April 21, 1959. Thus, the populations in both Mindong and Daiquyang waters should be the same population with mutual inhabitation. Second, the East China Sea coastal current and the Taiwan Warm Current affect the coastal waters of Fujian and Zhejiang year round. Therefore oceanographic conditions are unlikely to cause population isolation.

Abstract:We evaluated the population structure, growth and fecundity of Saurida undosquamis (Richardson) in the Beibu Gulf using biological data obtained from bottom trawls conducted during 1959−1960, 1992−1993, 1997−1999 and 2009−2010. The mean body length of S. undosquamis decreased from 185.5 mm in 1959−1960 to 163.1 mm in 1992−1993, 133.2 mm in 1997−1999, and 130.5 mm in 2009−2010. Similarly, mean body weight decreased from 66.5 g in 1959−1960 to 46.4 g in 1992−1993, 23.8 g in 1997−1999, and 22.6 g in 2009−2010. The asymptotic length (L), growth coefficient (k), and zero-length age (t0) in the von Bertanaffy growth equation during the periods 1959−1960, 1992−1993, 1997−1999, and 2009−2010 were 497.8 mm, 0.26, -0.49; 424.1 mm, 0.28, -0.48; 385.3 mm, 0.33, -0.41, and 342.5 mm, 0.39, -0.36, respectively. The inflexion age of body weight decreased from 4.05 years between 1959−1960 to 3.66 years between 1992−1993, 3.05 years in 1997, and 2.43 years between 2009−2010. Body length at 50% sexual maturity (L50) decreased from 111.2 mm between 1959−1960 to 105.2 mm between 1992−1993, 95.6 mm between 1997−1999, and 96.7 mm between 2009−2010. For the same body length, the current individual relative fecundity of S. undosquamis increased by 56.4% compared to the early 1960s. The changes in the life history traits of S. undosquamis in the Beibu Gulf during the last five decades suggest that the stock has undergone fishing-induced evolution (FIE), characterized by miniaturization, an increase in the speed of growth, and a decrease in time to maturity.

Abstract:Outbreaks of grass carp hemorrhage have caused widespread economic loss to the freshwater aquaculture industry in China. The disease is caused by grass carp reovirus (GCRV). Currently, strain HZ08 is responsible for the majority of outbreaks of grass carp hemorrhage. We developed a rapid, efficient, and specific method for detection of GCRV epidemic causing strains. We designed a pair of specific primers and TaqMan probes targeting the HZ08 strain S7 gene. The standard curve was established using the standard template plasmid PVAX1-S7, which exhibited a corresponding relationship between the Ct and the copies of plasmid. We then evaluated the specificity, sensitivity, and repeatability of this approach. The linear relationship of copies was excellent within the range 6.0×1010−6.0 (r=0.999 9). Using FQ-PCR we were able to detect at least 6.0 copies of the S7 gene in the plasmid suggesting this method has high sensitivity. The coefficients of variation were 0.82 and 0.41%−0.52% for intragroup and intergroup, respectively, indicating that this method had high repeatability. Furthermore, the method had high specificity, based on the lack of amplification of other aquatic viruses. We tested 32 suspected grass carp hemorrhage specimens and returned 28 positive samples using FQ-PCR but just 23 positive samples using conventional RT-PCR. In summary, we developed a FQ-PCR method for the detection of HZ08 strain GCRV that has high specificity, sensitivity, and repeatability. Our method may also be applied to GCRV rapid detection and preliminary quantification.

Abstract:Polycyclic aromatic hydrocarbons (PAHs) have two or more benzene rings, are persistent in the environment, and are carcinogenic, teratogenic, and mutagenic to most organisms, including humans. We evaluated the distribution and source of PAHs near Lingdingyang in the Pearl River Estuary. We measured the concentration of sixteen polycyclic aromatic hydrocarbons (PAHs) in the surface sediments collected at 20 sites in June, 2010 using GC-MS. We detected 15 PAHs at all sites, but the distribution of the remaining PAHs was uneven. Concentrations ranged from 143.9–522.67 ng/g (mean: 287.05 ng/g), and were not particularly high when compared with other developed areas throughout the world. The highest levels occurred near the NanSha port of GuangZhou and Shenzhen Baoan district. This is likely due to discharge from logistics, oil, and auto manufacture. The PAHs were divided into five groups based on the number of rings (maximum = 3). We used the isomer ratios (e.g., phenanthrene/anthracene and fluoran- thene/pyrene) to assess the origins of PAHs. The ratio of fluoranthene/pyrene was below 1 at 85% of sites, suggesting that the contribution of petroleum to PAHs was high, and that coal fuel combustion contributed relatively little. To confirm this, we used the Pyr/B(a)P ratio method and obtained similar results. We used the low-mid level of the effect range and the quotient of the mid-value of the mean effect to assess the ecological risk. Our analysis suggests that the risk to organisms is small if the PAH content is lower than the ERL. However, if the PAH content is between the ERL and ERM, there may be some risk and if the content is >ERM, the risk is high. The levels of two PAHs (Ace and Fl) were between the ERL and ERM at three sites. All other PAHs were below the ERL, so posed little risk. We detected high molecular weight PAHs [I(1,2,3)P] at 9 sites. These PAHs have no minimum safety value so likely pose a risk to organisms living at these sites. All MERM-Q values were below 0.1 indicating that the risk was low at all sites.

Abstract:We used stable carbon and nitrogen isotope analysis to identify the proportion of aquaculture-derived organic matter in the sediment in and around a coastal fish farm in China. The mean δ13C values were (17.72 ± 1.2)‰ and (12.73 ± 0.38)‰ in the regions around the fish farm (within 100 m from the edge of cages) and the control area (500 m from the edge of cages), respectively. The mean δ15N values were (6.44 ± 0.2)‰ and (5.61 ± 0.2)‰, respectively, for the same areas. The sediment near the fish farm contained a high proportion of waste feed and fish feces (47.70% and 27.71%, respectively). As the distance from the cages increased, the amount of aquaculture-derived organic matter decreased exponentially (y=97.167e-0.0074x, R2=0.848 1). The spatial extent of waste dispersal extended to an area up to 400 m due to bioturbation by wild or escaped fish and resuspension events. The waste organic matter generated by fish cage aquaculture is the primary source of organic pollution in the sediment of Nansha bay.

Abstract:We sequenced and analyzed partial nucleotide sequences of Cyt b and COⅠgene for Nemipterus species,including Nemipterus virgatus, N. japonicus, N. bathybius, N. nemurus, N. mesoprion, and the COⅠgene of N.hexodon, N. peronii and N. furcosus from GenBank. The results show that there are little different in nucleotide base of Cyt b (425 bp) and COⅠ (507 bp) . The divergence of sequences and genetic distances are tiny in N. japonicus and N. nemurus (COⅠ0.25% and 0.003, Cyt b 0 and 0) which suggest they have very closed relationship. And the Nemipterus species belongs to one genus, including N.peronii since the N. japonicus and N.mesoprion are in different branches. From the NJ phylogenetic trees, N. japonicus and N. nemurus are the latest differentiation species, N. virgatus is the oldest one . Molecular evolution rate (2% every million year in Cyt b ) showed the divergence of Nemipterus species occurred during the middle pleistocene epoch. It is a reference of the classification of Nemipterus species.

Abstract:We developed a growth model for Panulirus ornatus by measuring the length of individuals during different growth periods during rearing in the laboratory. Growth was explained by the following equation: W= 0.035 8× L3.043 2. The body immortal length was explained by the equation Lt=56.0×[1-e−0.053 1(t−1.1944)]. The relationship between body length and carapace length was L=2.772 2CL + 0.337 9. The body weight growth equation was Wt= 7 481.2×[1-e−0.0531(t−1.1944)]3. The rate of change in body immortal length was explained by Dl/Dt=56.0×0.0531× е−0.0531(t−1.1944). The rate of change in body weight was explained by dW/dt=3×7 481.2×0.053 1×е−0.053 1(t−1.1944)× [1-е−0.053 1(t−1.1944)]2 . The inflection point age of P. ornatus was 14.56 months, calculated using the formula Tr = ln3/K+t0. Body length increased more rapidly during the early period. Conversely, body weight increased more rapidly in the later period. The body weight growth curve was represented by an asymmetrical S curve, but had an inflection point. The body weight increased up to a maximum of 79.24 g•month−1 at the inflection point.