Abstract:The effects of different temperatures and photoperiods were studied on growth, feed conversion rate and relative expressions of growth hormone receptor Ⅰ (GHR1),growth hormone receptor Ⅱ (GHR2),insulin-like growth factor (IGF)and insulin-like growth factor binding protein (IGFBP) of young Amphiprion ocellaris.The results showed that there was no significant difference among the survival rate of young Amphiprion ocellaris under different temperature and photoperiod conditions(P>0.05). The growth rate and feed conversion rate of fish in 27℃ group were higher than those in other groups. In the photoperiod test, the growth rate and feed conversion rate of fish in 24L:0D group were significantly higher than those in other groups(P<0.05). At the end of the experiments, the expressions of several growth-related genes were investigated. The fish in 27℃ group showed the highest expressions of all the genes investigated(P<0.05). In the photoperiod test, the fish in 24L:0Dgroup showed the highest expressions of all the genes investigated(P<0.05).These results indicated that the most suitable temperature and photoperiod for growth were 27℃ and 24L:0D.

Abstract:As a member of DEAD-box family, Vasa is considered to be one of the molecular markers of germ cells. In this study, full length of Vasa cDNA in discus fish (Symphysodon haraldi) was cloned and expression in different tissues was analyzed. The results showed that the full-length of cDNA was 2 370 bp, containing a 123 bp 5'-untranslated region, a 279 bp 3'-untranslated region and a 1 968 bp open reading frame, encoding 655 amino acids. Alignment analysis indicated that the amino acid sequence of Vasa gene in discus fish was most identical with tilapia (Oreochromis niloticus). PCR analysis showed clearly that the Vasa gene was especially expressed in the gonads of mature fish, while it was not expressed in the other tissues. qRT-PCR analysis indicated that the Vasa gene was expressed from the whole embryonic developmental stages to the first 50-days juveniles. The Vasa gene expression increased continuously from fertilized eggs to blastula stage, then decreased from blastula stage to hatching. At larval stages, Vasa exhibited the lowest and highest expression on 25 dph (days post hatching) and 40 dph, respectively. By comparison, the expression in testis increased after reproduction which is contrast to the ovary. The findings in this study can provide information to study sexual differentiation, molecular markers and development of germ cell in discus fish.

Abstract:Goldfish Tgf2, a transposon of Hobo/Activator/Tam3(hAT) superfamily, encodes active transposase which is capable of mediating gene insertion and mutagenesis in a series of fish species. Therefore, it has great potential in applications such as screening master genes of important traits, functional explanation of genes and fish breeding. For existence of many rare codons in Tgf2 transposase cDNA (Tgf2TP, JN886591), Tgf2TP was optimized based on codon preference of E. coli. The synthesized Tgf2TP was then cloned into pET-28a(+) and transformed into BL21(DE3) cells. After incubation at temperature (37℃) and induction when OD₆₀₀≈0.5, the cells produced high yield of recombinant proteins, which accounted for 8.8% of total proteins in cells and 4.0% of supernatant proteins in lysates. By affinity chromatography purified recombinant protein (70 ku) was obtained, subjected to MALDI-(TOF)/TOF and identified as Tgf2 transposase (Tgf2TP). Then size exclusion chromatography was applied to evaluate DNA-binding activity of Tgf2TP. The results showed that recombinant Tgf2TP recognized and bound specific DNA probes containing sub-terminal repeat sequences of Tgf2, which means start of transposition. The prokaryotic expression system for Tgf2TP not only provided soluble and active transposase efficiently, but also laid a foundation for Tgf2TP used as enzyme tools in a variety of fish biology research.

Abstract:Comprehensive studies on triploid induction technology will greatly improve the development of Takifugu bimaculatus industry. This study applied hydrostatic pressure method to induce T. bimaculatus triploidy and investigated optimal inducing conditions of the starting time, the pressure and the treatment duration. Results showed that 96.67% triploid rate and 77% hatching rate were achieved under such condition:treatment temperature as 18-20℃, starting at 5 min after fertilization, hydrostatic pressure as 10-15 Mpa and treatment duration as 5-7 min. This is the first report for T. bimaculatus triploidy by hydrostatic pressure,which may provide an efficient technological process for T. bimaculatus triploidy. It also can offer a good reference for triploid induction in other Takifugu species.

Abstract:Far east wrasse Pseudolabrus eoethinus (Richardson, 1846) was previously synonymized with a Japanese wrasse P. japonicus (Houttuyn, 1782). Due to their morphological similarities, there are taxonomic confusions with both, which results in erroneous records and misidentifications in taxonomy. A redescription of P. eoethinus was given based on the specimen collected from Fujian Province. Through the comparison of P. eoethinus and P. japonicus, we identified several clear characteristics to distinguish them. P.eoethinus can be distinguished from P. japonicus by (1) the surface of head with a darkly curve stripe extending from the margin of the upper jaw to the base of pectoral fin through the lower edge of eye (the stripe on the surface of head is straight, not up to the base of pectoral fin); (2) the muciferous canals on lateral line scale were formed of bifurcations thrice repeated (the bifurcated canals on each scale were more than thrice repeated); (3) predorsal scales 8 (predorsal scales 5); (4) dorsal spines without blotch (a dark blotch between third to sixth dorsal spines).

Abstract:Micropercops swinhonis is a freshwater sleeper widely distributed in the Yangtze River drainage and other main drainages in northern China. We collected individuals from Songhua Jiang, Liao He, Hai He, the lower drainage of Yellow River (Puyang), Gaoyou Hu and the Yangtze River drainage (Shaoyang Zishui, Honghu, Jingzhou, Jiangjiang, Chaohu, Taihu, Langxi and Dongting Hu). Population genetic structure and divergence of M. swinhonis among different areas were investigated by analysing the sequences of mitochondrion cytochrome b (cyt b) and control region (D-loop). Concatenating sequences of cyt b and D-loop of 88 individuals resulted in 63 haplotypes and 133 variable sites. AMOVA, SAMOVA, analysis of haplotype network and phylogenetic reconstruction all supported splitting M. swinhonis into three groups:Shaoyang (Zishui; clade A), Taihu (clade B) and the population of other areas (clade C), which could be further divided into three subclades. Mismatch distribution revealed that populations from Jingjiang (Fu's FS:-4.119, P=0.009) and Honghu (Fu's FS:-2.814, P=0.016) probably experienced a recent expansion.

Abstract:In in-situ and non-situ modes, new GIFT tilapia (Oreochromis niloticus) was cultured with biofloc technology (BFT) for 120 d. Initial body mass of tilapia was (19.76±2.44) g, (21.01±1.23) g, and initial culture density was (2.63±0.33) kg/m³, (2.80±0.17) kg/m³. At the end of the experiment in situ group (control group) and non-situ group (treatment group),the weight of experimental fish were (306.21±18.64) g, (338.49±19.35) g. The culture density reached (33.29±0.83) kg/m³, (37.99±2.34) kg/m³. Ammonia nitrogen and nitrite nitrogen were accumulated in the early stage, but in the middle and late stages, the concentration of ammonia N was maintained below 3 mg/L and nitriter N maintained below at 2 mg/L. Nitrate nitrogen concentration has been accumulated in the whole experiment. The water quality of the treatment group was more stable than that of the control group. There was no significant difference in crude protein concentration between the two groups. There was no significant difference in stomach protease activity in each period, but the final activity was slightly lower than the initial activity. The trypsin activity in the intestinal tissues of the control group was higher than that in the treatment group during the whole breeding period. There was no significant difference in stomach lipase activity and intestinal lipase activity in the two groups.The experiment provides reference for the application and improvement of biofloc technology in production practice, through studying the effects of two kinds of bioflocculation modes on the production of new GIFT tilapia.

Abstract:In order to understand the effect of domestic fish meal with exogenous additives replacing the imported fish meal on China soft-shelled turtle (Trionyx sinensis), six groups of soft pellet feeds were designed and formulated with 67% of imported fish meal group(IFM), 34% of domestic fishmeal +32% imported fish meal group (DFM+IFM), 67% of domestic fish meal group (DFM), 67% of domestic fishmeal based group added 0.2% yolk antibody Group (DFM-Y), 0.05% sodium butyrate (DFM-S) group and 0.05% Bacillus subtilis group, (DFM-B), respectively. Relative weight gain rate and survival rate of Chinese soft shelled turtle(Trionyx sinensis) were calculated at 15 d, 30 d and 60d respectively. Meanwhile, in feeding behavior test, the above feeds were individually marked with one of the rare earth oxides (La₂O₃,Dy₂O₃,Sm₂O₃,Nd₂O₃,Yb₂O₃ and Y₂O₃) at 100 mg/kg, and the feeding preference was measured by the concentration of rare earth elements in feces and in the feed determined with inductively coupled plasma atomic emission spectrometry. Results showed that, 6 different diets did not affect the survival rate of Chinese soft shelled turtle; the growth of the turtle fed with the diet containing Bacillus subtilis could be significantly better than DFM group in 60-day feeding period, even not significantly different for IFM group in 30-day feeding period, while with yolk antibody and sodium butyrate enhancing growth performance only in the early feeding stage(15 d) of the juvenile soft-shelled turtle; feed containing mixture of domestic fish meal and imported fish meal was easier to attract juvenile soft-shelled turtle ingestion. There was no improved feeding effect of egg yolk antibodies, sodium butyrate and Bacillus subtilis in domestic fish meal. There was also no corresponding relationship between initial feeding preference and the growth of juvenile turtle, illustrating the feed ingestion was not the determinant for growth.

Abstract:This experiment was conducted to assess the effects of dietary protein (44%,48% and 52%) and antibacterial peptide (0.01% and 0.02%) on growth performance, serum biochemistry, digestive enzyme and antioxidant abilities of grouper (Epinephelus akaara). The experimental diets were named as:D1 (44%, 0.01%), D2 (48%, 0.01%), D3 (52%, 0.01%), D4 (44%, 0.02%), D5 (48%, 0.02%) and D6 (52%, 0.02%). Each diet was fed to 3 replicates and the experiment lasted for 8 weeks. The results show as follows:In certain range, Weight gain (WG), specific growth rate (SGR) and feed conversion ratio increased with protein level and ABP concentration increasing, and D5 was significantly higher than D1 (P<0.05). The morphological indexes, Hepatosomatic index (HSI), Viscerosomatic index (VSI) and Intraperitoneal fat index (IPF) of D6 were significantly lower than D5 (P<0.05). Crude fat content of fish fed diet D4 was significantly lower than D1 (P<0.05). Serum total protein (TP) and albumin (ALB) increased with protein and ABP increasing (P<0.05), glutamic-pyruvic transaminase (ALT), glutamic oxalacetic transaminase (AST) and glucose (GLU) were lower in D3 and D5 (P<0.05). Trypsase of D5 was higher than other groups (P<0.05), and Peroxidase (POD) of D1 was significantly lower than other groups (P<0.05). ABP could increase Pepsin, Catalase (CAT), POD and decrease Malondialdehyde (MDA) content (P>0.05). The result shows 0.02% ABP supplementation at 48% protein level can improve growth, increase digestive enzyme activities and antioxidant abilities, and decrease FCR.

Abstract:To improve the disease-resistant ability and maintain good aquatic environment, experiments were carried out in 12 ponds in Beiyang Aquafarm located in Dongsheng Town of Zhongshan City by combination use of inoculating quadrivalent vaccine and beneficial microorganisms in grass carp (Ctenopharyngodon idellus) aquaculture. The results indicated that when grass carp was inoculated, antibody titer was detected 7 days later, with maximum value in 30 days, and even sustained until the experiments ended. The average survival rate of grass carp in quadrivalent vaccine immunized group was 29.7%, significantly higher than control group (P<0.01), and the relative percent survival was 90.9%. Use of beneficial microbes was useful to improve water quality, optimize the aquaculture conditions, and raise the average survival rate (7.9%, P<0.01). The average survival rate of grass carp in combination use of inoculating quadrivalent vaccine and beneficial microorganisms group was 31.7% (P<0.01) higher than control group, and the relative percent survival was 96.6%. All the average daily gain, net gain, weight gain rate and specific growth rate were increased, and the food coefficient was declined in 3 treatment groups. The profits of the 3 treatment groups were 875,1854,2 255 yuan higher than control group respectively (P<0.05). The results showed that the disease-resistant ability, the average survival rate and the growth rate of grass carp were raised, and the aquatic environment was improved by using quadrivalent vaccine and beneficial microorganisms together, showing a great synergistic effect and opening up a new way of cooperative application.

Abstract:Overuse of antibiotics, such as erythromycin through different ways go into the water, then into the sediment, causing harm to aquatic ecosystems. The benthic animal Cipangopaludina chinensis exposed to roxithromycin, were detected the ERND in the stomach, liver, kidney and ovary, examining the impact of roxithromycin on the activity of ERND enzyme in C. chinensis. The results showed that with the P450 isoform of cytochrome P450 activity, but they are in the distribution and activity of tissues and organs does not show difference in C. chinensis. Continuous administration to the C. chinensis,The ERND activity in liver, kidney, stomach, ovary and muscle tissue increased obviously, the dose effect relationship to reach the highest point in 3 days, and began to decline in 4 days. The overall trend is promoting more than restraining, but the inhibitory effects of different concentrations of roxithromycin have not great difference. From the point of view of the survival status of the control group and the experimental group of each snail, roxithromycin as an antibiotic, has no lethal effect on C. chinensis, but 250 times the concentration used in this experiment, 500 times and 750 times the concentration of environment can produce concentration has obvious influence on the ERND activity in tissues of C. chinensis.

Abstract:In order to understand the direct and indirect effects of Daphnia magna on phytoplankton composition in unfiltered raw water that contained in situ zooplankton, and which densities of Daphnia magna will control phytoplankton effectively, we carried out a simulated experiment in May 2016. The experiment had one control (C0) group and four treatment groups C1, C2, C3 and C4. We added D. magna at five different levels (0, 5, 15, 25 and 50 ind./L). Each treatment had triplicates and lasted for 10 days. The results indicated that both low (C1 and C2) and high (C3 and C4) densities of D. magna could suppressed phytoplankton abundance, but the latter is more effective. Daphnia magna prefer grazing green algae and phytoplankton whose particle size is between 20 μm and 30 μm. Moreover, it can suppress abundance of Bosminopsis deitersi, Diaphanosoma leuchtenbergianum, Cyclops, rotifers and protozoa, and the higher the density is, the stronger inhibitory effect (except protozoa), affecting phytoplankton community indirectly. Additionally, we found addition of D. magna at 25 ind/L performed best, which reduced the abundance of algae dramatically, fell by 75.1%, on the fourth day.

Abstract:The heart rate and feeding behavior of one-day and 12-day-old Daphnia magna were studied at eight pH values (4-11) and eight salinities (1-8). The effects of pH and salinity on two ages of Daphnia magna exhibited the similar tendency——to promote at low and to suppress at high. The adaptability to alkaline water is greater than that to acidic water. The optimum requirement of young and old Daphnia magna were 6-8 and 7-9 for pH, 2 and 3 for salinity, respectively. The metabolism of young individuals was higher than the old, and the young were more sensitive to pH and salinity change, but less adaptable to adverse external environment. The heart rate of the young Daphnia at pH 10 and at salinity 5 was (372.1±15.1) and (365.3±10.2) with highly significant difference from the control (P<0.01), higher than the old but narrower adaptability. At pH 8, the filtration rate and feeding rate of the young Daphnia reached maximum and the feeding rate was significantly higher than the control (P<0.05), just as the regularity of the old at pH 9. At the salinity of 2, the filtration rate and feeding rate of young population were the highest, both significantly higher than the control, similar to the old at the salinity of 3. It can be concluded that different ages of Daphnia magna have different optimum pH and salinity, so pH and salinity should be reasonably adjusted to maximize the production.

Abstract:Chlorella pyrenoidosaChick and Photosynthetic Bacteria were immobilized by sodium alginate and calcium chloride for aquaculture wastewater purification, and the purification capacity was investigated. The conditions of its immobilization were studied by orthogonal experiments.The results showed that algae-bacterium immobilized balls which were embedded by 2% sodium alginate and cross-linked for 24 h by 6% calcium chloride improved orthophosphate and ammonia-nitrogen removal efficiency, which respectively reached 84% and 95% at 24℃. It was higher than immobilization algae and bacterium separately (P<0.05) for orthophosphate during the periods of first-forth days and for ammonia nitrogen during the periods of fifth-eighth days. The studies indicate that the purification capacity of algae and bacterium can be improved significantly for aquaculture waste water by using algae-bacteria combination and to be fixed reasonably. Applying algae-bacterium immobilized balls has better effect than adopting algae and bacterium separately in purification efficiency of aquaculture wastewater.

Abstract:A survey of seasonal distribution characteristics of nutrients in the East China Sea standard sections was carried out in 2015. Based on the survey data in four seasons from East China Sea standard sections (mean values in May, August, November and February represent values in spring, summer, autumn and winter, respectively), seasonal distribution characteristics and variations in contents of five nutrients at the surface, at the depth of 10 m and at the bottom were comprehensively analyzed. The main impact factors were also discussed in this paper. The results show that the highest inorganic nitrogen, phosphate and silicate contents occurred at the bottom of the content, almost with an increasing trend from surface to the bottom. In the East China Sea in 2015, the distribution of nutrients has obvious seasonal variations, and phosphate content and inorganic nitrogen content are higher in autumn and winter than those in spring and summer. Silicate content is higher in summer and winter than that in autumn and spring. The main source of nutrients in the East China Sea is the Changjiang river diluted water, and the Taiwan Warm Current also carries a portion of nutrients into the East China Sea. The combined effect of the Changjiang river diluted water and Taiwan Warm Current makes the nutrients concentration in East China Sea decrease from west to east.

Abstract:Ocean environmental data are urgently needed in the exploitation, management and protection of marine fisheries resources. The large-area, long-time-period and near-real-time ocean environmental data can be collected by using satellite remote sensing and the technology of satellite remote sensing is playing an increasingly important role in the exploitation, management and protection of marine fisheries resources. In this paper, we reviewed the applications of satellite remote sensing data in fishery stock assessment, fishery forecasting, classification and conservation of marine fish habitat, vessel monitoring, fishery safety and fishing gear and methods. Meanwhile, we also discussed the problems of the applications in fisheries and presented prospects for the future development. The review is presented as a reference for scholars to understand the role of satellite remote sensing in the exploitation, management and protection of marine fishery resources.

Abstract:Squid is one of the important economic species in the northwestern Pacific. Using Catch per Unit Effort and V% as the target of central fishing ground and adopting BP artificial neural network, we forecast fishing ground in the northwest Pacific Ocean. The study was based on the data of squid fishing and relevant marine environment factors, including longitude, latitude, SST and SSHA from July to November from 1995 to 2001.The input factor is marine environment factor, the output factors are CPUE and V% and 4-3-1 and 4-2-1 model total 4 kinds models were used to compare which is the best suitable model for fishery forecast. The minimum fitting residual of model is the best one. Result shows that 4-3-1 is the best suitable model for each month, but the best suitable model for July and August is 4-3-1 with output V% and best suitable model for September, October and November is 4-3-1 with output CPUE, the minimum overall average error is 4-3-1 model output V%. Research suggests that there are differences as a center of fishery forecast targets by CPUE and V%, and the 4-3-1 model output V% can be used as forecasting model of squid fishing ground.

Abstract:Based on the 362 samples of Octopus ocellatus collected during August to October of 2015 in the continental shelf of northern South China Sea,the biological characteristics were studied.The result indicated that the mantle length (ML) ranged from 24 mm to 67 mm, with an average of 43.2 mm, with a high concentration of 35 mm to 50 mm, accounting for about 70.9% of all the samples, and the body weight (BW) ranged from 9 g to 124 g, with an average of 37.0 g, and with a dominative weight from 13 g to 52 g, accounting for about 83.8%, respectively. The composition of ML and BW was different among different waters, and the samples in the Beibu Gulf waters smaller than those in the north of South China Sea. The relationship between the ML to BW was best described by the power function by the Akaike's information criterion (AIC), respectively. The ratio of females to males was 0.66:1. However, individual in the north of South China Sea waters is given priority to with maturity stage, accounted for 66.44%, while in Beibu gulf waters, almost all in the immaturity stage. The feeding stage was mainly in 0 and 1 grades, accounting for 91.4% of all the samples and the food was mainly composed of crustacean.

Abstract:As the idea of the 200-nautical mile fisheries jurisdiction has been widely supported by third world countries, forced by the development of the world situation, the United States announced the establishment of 200-nautical-mile fishery protection zone in 1976, and set up eight fishery management councils within 3-200 nautical miles for the need of fishery management. The council is a quasi-official organization. The members of each council must be individuals with occupational or other experience, and are knowledgeable regarding the conservation and management, or the commercial or recreational harvest. It changes the fishery management model of the United States, from the government-oriented to the government and fishery stakeholder group to consult. The paper analyzes the historical background, function, organizational structure and decision-making procedures of the councils. Finally, it is proposed that our country should make the decision-making process procedural requirements, perfect the support mechanism and establish a process to ensure public participatiton, to improve the fisheries decision-making mechanism.

Abstract:Consumers' demand for freshness and safety of live aquatic products has become stricter and stricter in recent years, and live products transportation has become an effective way of keeping products fresh. However, there are some problems about domestic live products transport technology, such as the low degree of informative and intelligence control plus single monitoring factor, which are all urged to be solved. In view of the above, one intelligent monitoring system was designed for live aquatic products transportation. By the design of hardware and software, it realized the real-time monitoring of water temperature, pH, dissolved oxygen and other water quality parameters as well as the video data storage in the transport carriage. This system constructs three levels of Internet of Things (IoT), which are bottom sensor detection and control, center data controlling and processing, remote terminal management. It realized the remote intelligent monitoring of live aquatic products transportation by using wireless transmission technology. In addition, the system has designed an host monitoring interface by using LabVIEW, it is not only able to monitor the real-time water quality parameters and video data storage in the transport carriage, but also established a database of aquatic products which can be used to inquire the historical data. The system has been tested by small transport vehicles for live tilapia, which proved that the system is easy to operate and stable, reliable and practicable.