Recent Advances in Population Genomics of Marine Fishes

In recent years, advances in high-throughput sequencing technique and capacity of big data analysis have facilitated genomics research in many species. Genome sequencing, single nucleotide polymorphism （SNPs） identification and population transcriptomics are conducive to understanding the evolutionary progress and regulatory mechanisms of genes related to adaptive traits in organisms, which poses great significance to the theoretical research and productive practice. Fur- thermore, population genomics of marine fishes can deepen the understanding of important microevolution events, such as genetic differentiation, hybridization and speciation. Therefore, the related research contributes to better understanding of the evolutionary process of marine organisms and provides theoretical evidences for the development of aquaculture industry and nmnagement and protection of marine fishery resources.

Recent progress in the understanding of the gut microbiota of marine fishes

As the significance of the gut microbiota has become increasingly realized,a large number of related studies have emerged.With respect to the gut microbial composition of fish,the predominant gut microbes and core gut microbiota have been reported by many researchers.Our understanding of fish gut microbiota,especially its functional roles,has fallen far behind that of terrestrial vertebrates,although previous studies using gnotobiotic zebrafish models have revealed that the gut microbiota performs a significant role in gut development,nutrient metabolism and immune responses.Given that environmental factors of marine habitats are very different from those of freshwater habitats,a distinct difference may exist in the gut microbiota between freshwater and marine fish.Therefore,this review aims to address the advances in marine fish gut microbiota in terms of methodologies,the gut microbial composition,and gnotobiotic models of marine fish,the important factors(host genotype and three environmental factors:temperature,salinity and diet)that drive marine fish gut microbiota,and significant roles of the gut microbiota in marine fish.

ARTIFICIAL PROPAGATION AND BREEDING OF MARINE FISH IN CHINA

Since the 1990s, artificial propagation and breeding technique of marine fish in China have developed by way of increasing species and fry numbers, with special stress laid on valuable species. Large quantities of artificial fry can meet the needs of both marine cage culture and pond culture for most species. Experimental results obtained by scientists have been put into use in actual production. Fish fry production has entered a period of sustainable development. So far, at least 44 species (21 families) of marine fish have been successfully bred in China. The artificial fry number of large yellow croaker (Pseudosciaena crocea) exceeded 300 million in 1999. The species whose artificial fry numbers have each surpassed 10 million annually are red drum (Sciaenops ocellatus), Japanese seabass (Lateolabrax japonicus), cuneate drum (Nibea miichthioides), spring spawning red seabream (Pagrosomus major) and threebanded sweetlip (Plectorhynchus cinctus). Millions of artificial fry are bred annually in the species of black porgy (Sparus macrocephalus), Russell’s snapper (Lutjanus russelli), javelin grunt (Pomadasys hasta), miiuy croaker (Miichthys miiuy) and skewband grunt (Hapalogenys nitens). The fish in the family Sciaenidae are the main species in artificial propagation and breeding. Some problems and prospects on marine fish culture and stock enhancement are also discussed and some proposals for sustainable development are put forward in this article.

Transaction of Marine Fishing Right: Theoretical Analysis

The difference between fishermen’s fishing catch and the optimal fishing catch is the basic reason for the transaction of marine fishing rights (TMFR). The effects of productive cost, non-productive cost, use-cost, transaction cost, productive revenue and non-productive revenue on the TMFR and the optimal fishing catch are analyzed. This paper draws following conclusions: the non-productive revenue has a positive effect on the TMFR, and other factors, such as non-productive cost, usecost and transaction cost, have a negative effect; the TMFR will promote the resource allocation; the high transaction cost may affect the implementation of TMFR.

Consumer Preference and Consumption Pattern of Marine Fish Species in Ibadan Metropolis, Oyo State, Nigeria

Despite the nutritive value of finfish, the domestic production is inadequate to meet the national demand. Due to the high demand of 2.66 million metric tons per annum for fish, Nigeria imported 740,000 tons in 2007 to supplement the domestic production of 615,507 tons. A study was conducted in Ibadan Metropolis of Oyo State （a land locked state） to determine the consumer preference and pattern of marine fish species consumed. Stratified sampling method was used to select respondents from three income earning levels of the five local government areas in Ibadan Metropolis. Questionnaires were administered to 51 marine fish retailers and 151 households. Data collected was analyzed using descriptive statistics and Tobit regression model. Marine fish sellers ranked horse mackerel （Scomberjaponicus） first and croaker （Pseudotholithus species） the least because it is more priced. Only 10.6% and 13.2% of the households preferred express （Brevortia species） and croaker respectively, but Hake （Gadus gadus） was the least preferred （41.7%）. The household consumed varying proportions of fish species every week. The regression result （R2 = 0.65） showed that married household heads with large household size having lower years/level of education, younger in age and earning lower income are likely to consume more of marine frozen fish species （P 〈 0.01） than others.

Current Situation and Problems of Marine Fishery in China

Marine fishery plays an essential role in promoting the employment of labor force,ensuring food safety,promoting the construction of ecological civilization and safeguarding the maritime rights and interests. The development of marine fishery is of great significance. This paper analyzed the current situation and existing problems of marine fishery in China and came up with some pertinent recommendations and measures. The area of marine fishery with authentic right is increasing year by year,and pelagic fishery constantly grows and the industrial structure is becoming more and more reasonable. However,there are still problems such as serious pollution of marine environment,frequent occurrence of marine disasters,shrinking space of fishery development,which seriously affect healthy development of the marine fishery. In this situation,it came up with recommendations including strengthening monitoring of marine fishery resources and protection of marine environment,optimizing the industrial structure,and raising the scientific and technological level of marine fisheries,to protect the sustainable development of marine fishery. It is expected to provide references for the development of marine fishery in China.

Evaluation of the “fishing down marine food web” process in the north-west of Persian Gulf(Khuzestan Province) during the period of 2002–2011

The worldwide increase in commercial fisheries and its impact on ecosystems as well as inefficient fishery management have led to overfishing and frequent breakdown of traditional fish stocks. In this context, an analysis of Khuzestan inshore fisheries data covering the years 2002-2011, was conducted in reliance on testing for occurrence of the fishing down marine food webs （FDMFW） phenomenon in the North of Persian Gulf Large Marine Ecosystem （LME）. In this study, the mean trophic level （mTL） and the fishing-in-balance （FIB）-index of Khuzestan landings during this period of time were estimated using the trophic level of 47 fishery resources. Increase in total landings （I1） was observed, which explained the high fishing yield in major fishery resources （especially demersal）. Moreover, the moderates decreasing trend in mTL per decade, and the increasing trend in FIB-index were observed. The status of fishery resources in Khuzestan inshore waters （under exploited but not overexploited）, the rise in Y, FIB and slightly drop in mTL can be considered as indirect indicators of the fishing impacts on the trophic structure of marine communities. Based on this result, probability occurrence of FDMFW process in Khuzestan inshore waters is low to some extent. However, we suggest that the goal of management programs in Khuzestan inshore waters should prevent the continuance of this trend in the long-term using an ecosystem-based approach.

The Law of Marine Fishing:Challenges and Coping Strategies for Sustainable Marine Fishing in Ghana

Waters off the coasts of West Africa are very rich with many different types of fish and marine life.Some species like sardines,tuna,mackerel,tilapia and shrimps are important to many local communities and economies in West Africa.However,the current overfishing of these fish affects the sustainability of fishery industry.Despite Ghana ratifying to a number of international marine laws to ensure a sustainable marine fishing,there seem to be some challenges that are associated with marine fishing in Ghana.This paper further examines the strategies that have been employed by the fishing community and the fisheries ministry in Ghana as a response to restrictive measures for the challenges identified and discussed in literature.This paper is fundamentally an extensive review of marine fisheries literature.In general terms,it was found that,Ghana has ratified to a number of international marine laws including the UNCLOS.

Mineral Uptake of Heavy Metals by Some Marine Organisms along the Limbe Coastline in Cameroon and Health Risk Assessment

This study aimed at investigating the content of heavy metals in some marine organisms of the Cameroon Atlantic coast and assessing the health risk due to their consumption by the population. Nine fish and one shrimp species were collected for this study. These fish species were Ethmolosa fimbriata, Drepane africana, Dentex moroccanus, Arius latiscotatus, Scarus hoefleri, Cynoglossus browni, Sardinella madorensis, Pseudotolithus elongatus, Pseudotolithus typus. The shrimp species was Macrobranchium macrobranchium. The elements investigated in this study were: Fe, Co, Cu, Cd and Pb. For seven fish species it was found that the concentration of heavy metals followed the order Fe > Co > Cd > Cu > Pb. For most fish species the Target Hazard Quotient (THQ) value calculated showed the following trend Cd > Co > Pb > Fe ≥ Cu. Cadmium was found to be the main contributor to health risk that may result from the consumption of the fish species under study. The THQ for this element was in the range 0.7 - 1.2 while the Target Cancer Risk (TR) due to ingestion of this metal was in the range (3 × 10-4 - 6 × 10-4). These values are slightly above the threshold limits established for both carcinogenic and non carcinogenic risks by the United States, Environmental Protection Agency. The estimated weekly intake of cadmium due to consumption of some fishes under study was greater or equal to the Provisional Tolerable Weekly Intake (PTWI) determined by Food and Agriculture Organization/World Health Organization.

An assessment of “fishing down marine food webs” in coastal states during 1950–2010

Mean trophic level of fishery landings（MTL） is one of the most widely used biodiversity indicators to assess the impacts of fishing. Based on the landing data compiled by Food and Agriculture Organization combined with trophic information of relevant species in Fish Base, we evaluated the status of marine fisheries from 1950 to 2010 for different coastal states in Pacific, Atlantic and Indian Oceans. We found that the phenomenon of ＂fishing down marine food webs＂ occurred in 43 states. Specifically, 27 states belonged to ＂fishing-through＂ pattern, and 16 states resulted from ＂fishing-down＂ scenario. The sign of recovery in MTL was common in the Pacific, Atlantic and Indian Oceans（occurred in 20 states）, but was generally accompanied by significantly decreased catches of traditional low trophic level species. In particular, 11 states showed significant declining catches of lower trophic levels. The MTL-based assessment of ＂fishing down marine food webs＂ needs to be interpreted cautiously.

Studies on HUFA Biosynthesis in a Marine Teleost Siganus Canaliculatus

Marine fish are incapable or have a deft- cient capacity to synthesize highly unsaturated fatty acids （HUFA） from C18 precursors, and thus fish meal and fish oil （FO） are needed in their formulated diets.

UPLC-Q-TOF MS分析海洋鱼类血清皮质醇

A sensitive analytical method on cortisol in marine fish serum was established using ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry(UPLC-Q-TOF MS).The cortisol in marine fish serum was extracted with chloroform,dried under nitrogen gas,and solved in 1:1 methanol-H2O for analysis,with dexamethasone as internal standard.The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization in negative mode,with m/z 407.2 for cortisol and 437.2 for dexamethasone,respectively.The results showed efficient separation of cortisol and dexamethasone are achieved on BEH C18 column.The linearity was good with the equation : Y=0.0154X+0.0451,from 0 to 200 ng/mL,with correlation coefficient of 0.999 3 and low detection limit of 1.64 pg.The average recovery was from 93.3% to 98.1%,with SD less than 10%.Using this method,corsitol in yellow croaker and Japanese sea bass collected in Ningbo China,were determined with content ranged from 0 to 15.81 ng/mL.

Observation and analysis of morphology abnormalities in development of Oryzias melastigma embryos

Fish embryos are widely used as models in toxicology,drug development,and human disease research because of their high sensitivity,observability,and operability,providing the basis for an in-depth understanding of the embryogenesis.Increasing studies have indicated that birth defects are hereditary.In this study,we used Oryzias melastigma as a model to conduct a study of 185-day embryogenesis and observed self-induced non-pathological abnormal embryogenesis.O.melastigma experienced pre-puberty stage,adolescence stage,and senescence stage,and individuals produced up to 102 eggs per day.However,the fecundity was markedly reduced during the senescent stage.During the active egg and blastodisc stages,pseudo-fertilization and pseudo-blastocysts were observed.During cleavage at the 4-to 32-cell stages,we observed blastomeres separation or dislocation.Excessively separated blastomeres formed double blastoderms,eventually resulting in conjoined twins.During the blastula stage,we observed abnormally increased cell volume,narrowed and elongated blastocysts,and abnormally coated blastoderms.At the organogenesis stage,we observed abnormal numbers of Kupff er’s vesicles and conjoined twins.Abnormality in the location and number of oil droplets were observed in various development stages.Abnormal development was more commonly observed in fertilized eggs produced by broodstock in pre-puberty or senescence stages,which is probably related to the age of fish and the egg quality.This study can provide the materials for comparative analysis in toxicological and molecular studies of O.melastigma,and may provide evidence for other economic fish that produce sticky eggs.

Estimation of Mercury Intake from Consumption of Fish and Seafood in Russia

Data on the mercury concentration in freshwater and marine fish and seafood on the territory of Russia are presented. The level and pattern of the fish and seafood consumption in various regions of Russia are found from the analysis of open statistics. Regions with the maximum and minimum consumption of fish products are established. Mercury intake from these products in a human organism is calculated. It is shown that at the current level and pattern of the diet in Russia fish cannot be a source of high mercury concentrations in a human organism.

Parasite Fauna of Lutjanus synagris Commercialized in the Fish Market from Bragança-PA,Brazil

Studies about the parasite fauna of marine fish highlights as an important problem for public health with zoonotic parasites or affecting the fish quality.Thus,this study evaluated the parasite fauna of Lutjanus synagris commercialized in the fish market from Bragança-PA.In laboratory,58 fish were measured,weighted and conducted to parasitological analysis to determine parasitological indexes and relative dominance.Every parasite was fixed and identified until to the lowest taxonomic level.Through the parasitological analysis,it found Cymothoidae,Digenea,Cucullanus sp.and Procamallanus(Spirocamallanus)sp.,with total prevalence 67.24%.Digenea showed the highest prevalence and mean intensity values.For nematode,Cucullanus sp.obtained the greater prevalence and relative dominance,while Procamallanus(Spirocamallanus)sp.showed the greater mean intensity and abundance.Cymothoidae showed the lowest prevalence and mean intensity values.As conclusion,the parasite fauna of L.synagris has been noted with low diversity,reporting the nematode occurrence Procamallanus(Spirocamallanus).

Tissue-specific trace elements concentration and human health risk assessment in three marine fish species from Visakhapatnam to Kakinada coasts

Purpose The current study was aimed to evaluate the bioaccumulation of elements(As,Cd,Cu,Fe,Mn,Se and Zn)in the gills,liver and muscle of three distinct marine fish species,namely Nemipterus japonicas,Upeneus vittatus and Pampus argenteus species were collected from Visakhapatnam to Kakinada coastal waters.Methods The fish tissues were analyzed for trace metals using energy-dispersive X-ray fluorescence(EDXRF).To ensure the quality control,reliability of the experimental validation,two certified reference materials(CRMs)procured from National Institute of Standards and Testing(NIST SRM 1577c-Bovine Liver)and European Commission-Joint Research Centre,Institute for Reference Materials and Measurements(ERMBB422-Fish muscle)were analyzed using EDXRF.Results The evaluated estimated daily intake(EDI)values for each metal are below the reference dose levels established by World Health Organisation(WHO).The target hazard quotient(THQ)values of both the locations of the present study are lower than one(<1)except for arsenic and the combined target hazard quotient(CTHQ)values are higher than one(>1)showing the presence of health risk.The cancer risk(CR)factor value for arsenic was below the acceptable lifetime carcinogenic risk(10^(–5)).The levels of heavy metals varied significantly among three fish species and organs.The mean concentrations of As,Cd,Cu,Fe,Mn,Se and Zn were slightly higher than the Ministry of Agriculture,Fisheries and Food(MAFF),Food and Agriculture Organization(FAO),Turkish food codex and Brazilian Legislation standard levels.The findings of this study revealed that muscles possessed the lowest concentrations mostly of all the metals when compared with liver and gills.Conclusion The study concluded that consumption of the muscle tissue may not pose severe health risk to human health but should be consumed moderately to prevent bioaccumulation of the metals especially As.

Bioaccumulation and the expression of hepatic cytochrome P450 genes in marine medaka(Oryzias melastigma)exposed to difenoconazole

This study was conducted to assess the effects of difenoconazole（DFZ）, a triazole fungicide,on the hepatic biotransformation system and its bioaccumulation in marine medaka（Oryzias melastigma）. Fish were exposed to DFZ（1, 10, 100, 1000 ng/L） for 180 days. The results showed that：（1） The m RNA levels of hepatic CYP1A1, CYP1 B, CYP1C1, CYP27 B and CYP3A40 were up-regulated, but those of CYP3A38 and CYP27A1 were down-regulated.（2） The activity of ethoxyresorufin-O-deethylase（EROD） and the content of reduced glutathione（GSH） in the liver were increased in the DFZ-treated groups, and glutathione S-transferase（GST） activity was increased in the 100 and 1000 ng/L groups.（3） DFZ was accumulated in the muscle and the biological concentration factors in the 10, 100, and1000 ng/L groups were respectively 149, 81 and 25. These results suggested that long-term exposure to DFZ at low concentrations would result in a bioaccumulation of this compound and disturb the biotransformation system.