Abstract:Aggregation is a typical behavior of Antarctic krill (Euphausia superba, thereafter krill). The distribution and type of aggregation is also the focus of krill behavior study. Based on acoustic data collected by Antarctic krill resource survey, the aggregation of krill around the South Orkney Islands from January to February 2018 was investigated using the Simrad EK60 (38 and 120 kHz) echosounder. The results indicated (1) a total of 3224 krill aggregations were detected, and the depth, length, thickness, area and density of krill aggregation were (218.52±455.66m), (11.19±13.98m), (1894.40±9345.72m2), (96.00±64.33m) and (114.11±159.60 ind/m3), respectively. (2) in different periods of a day, significant differences were found between depth, length, thickness and area of krill aggregations, but density of krill aggregation hadn’t significant different. In different depths of krill aggregation, there were significant differences between depth, length, area of krill aggregation, but no significant differences were found between thickness and area of krill aggregation, respectively. (3) three distinct types of krill aggregation were classified. Type I had the highest density (325.90±221.30m), smallest area (379.64±433.73m2) and deepest depth (158.06±67.54m); type II had the longest length (1089.60±1189.56m) and the area (15601.25±30243.33m2) were much larger than other two types; type Ⅲ had the lowest depth (78.91±52.88m) and smallest density (48.87±50.33 ind/m3), but it had the highest number of krill in the aggregation.

Abstract:leptin is an important hormone involved in the regulation of feeding, reproduction and energy consumption in animals, it also can maintain body energy homeostasis by curbing appetite and promoting energy metabolism in vertebrates. Most fish have the double leptin genes. In this research, the coding region of leptin A was cloned using PCR reaction in Micropterus salmoides, the results showed that it's open reading frame (ORF) was 486 bp, encoding 161 amino acid proteins. Comparing with other species, it was found that the conservative property of leptin in perciformes reach up to 91.46%, there is almost no gene specific mutation site in leptin A of Micropterus salmoides, and the amino acid sequence of leptin A in Micropterus salmoides had the highest homology with the Siniperca chuatsi (92.59%), following with the Lateolabrax japonicus(89.51%), Trachinotus blochii (87.04%) and Epinephelus coioides (83.87%). Then, leptin A gene was also detected to be highly expressed in liver by fluorescence quantitative PCR (qPCR), subsequently in heart, head kidney, brain, middle kidney, intestine, spleen, gill, muscle and gonad. In addition, acute hypoxic stress was designed to detect the expression of leptin A [(1.2±0.2) mg/L and (3.5±0.2) mg/L]. the results showed that at the beginning of hypoxia, the expression level of leptin A in the extreme hypoxia group and the moderate hypoxia group was significantly higher than that in the control group, it indicates that acute hypoxia can induce leptin A expression in liver. In summary, leptin A of Micropterus salmoides has the highest homology with Siniperca chuatsi(92.59%); leptin A was significantly expressed in the liver of Micropterus salmoides; acute hypoxic stress can significantly induce the expression of leptin .

Abstract:Diptychus maculates steindachner is a unique species of the Muzati River in Xinjiang. This fish has been classified as a national secondary protected animal.The construction of cascade hydropower stations has had a great impact on fish resources. The construction of fish passage facilities is currently major protection measures. In order to provide reliable parameters and data for the design of fish facilities, the swimming capability of wild Diptychus maculates steindachner (total length TL=12 ~ 16 cm) from the Muzati River in Xinjiang was measured at 16.6 ± 1.6 °C water temperature. Results showed that the induction velocity was 0.18±0.02m/s (relative induction velocity was 1.40 ± 0.23 BL/S); the critical swimming speed was 1.02 ± 0.15 m/s (relative critical swimming speed was 8.58 ± 1.65 BL/S); the burst swimming speed was 1.39 ± 0.17 m/s (relative burst swimming speed was 10.92 ± 1.86 BL/S); the maximum sustained swimming speed was 0.87 m/s and the maximum prolonged swimming speed was 1.37 m/s, which was close to the average burst swimming speed. The swimming time was negatively related to swimming velocity( )．When the target fish of fishway is Diptychus maculates steindachner,it is recommended the flow rate at entrance was from 1.02 to 1.39 m/s for attracting fish into the fishway, and the main flow rate in the rest pool ranged from 0.2 to1.02 m/s．The highest velocity in the fishway should be less than0.85m/s. When the length of the fishway is 1000m, the average water flow velocity in the fishway should be less than 0.78m/s. This investigation provided a reference for the study of swimming capability of fish in the Xinjiang Muzhati River and are of great significance for the protection of endangered fish.

Abstract:Nonylphenol (NP) is the environmental endocrine disruptor that widely presents in water, which affects the growth and development of species. In order to explore the mechanism of nonylphenol-induced developmental malformation in red crucian carp (Carassius auratus red var.), red crucian carp was used as the research model, transcriptome sequencing (RNA-seq) of normal embryos in neural stage (NC), normal embryos in 21 somite stage (SC), monstrous embryos in neural stage and monstrous embryos in 21 somite stage that exposed to 5 μmol/L NP (SNP) were performed on Illumina HiSep 2500 platform. Furthermore, differentially expressed genes (DEGs) were verified by quantitative real-time PCR (qRT-PCR). A total of 89,166 high-quality Unigenes were obtained from RNA-seq, of which 30,319 Unigenes were annotated. Pairwise comparison among NC, SC, NNP and SNP showed that there were 153 DEGs in NC/NNP, 10 DEGs in SC/SNP, 6121 DEGs in NC/SC, and 7270 DEGs in NNP/SCP. KEGG pathway analysis revealed that most of these above DEGs were enriched to cellular processes, environmental information processing and metabolism signal pathways. 25 DEGs related to growth, development, cytoskeleton and cardiovascular circulation were verified by qRT-PCR. Their expression changes are consistent in qRT-PCR and RNA-seq. On the one hand, this consistency indicates that the RNA-seq results are reliable, on the other hand, the candidate genes of developmental malformation caused by NP stress are preliminarily excavated, which provides prophase data for further study on the molecular mechanism of NP teratogenesis.

Abstract:Effects of water temperature (4, 18, 25 and 37 °C) on deep-sea bacterial biofilms and subsequent effect on metamorphosis of larvae of the mussel Mytilus coruscus were studied. The confocal laser scanning microscopy technique was used to clarify the characteristics of biofilms including biofilm thickness and the distribution of extracellular polymeric substances. The biofilms formed by the deep-sea bacteria could promote the metamorphosis of larvae under four temperature conditions. Virgibacillus sp.1 showed the highest inductive activity (35%), with high α-extracellular polysaccharide secretion. The Virgibacillus sp.1 biofilm inducing activities on larval metamorphosis were correlated to seawater temperature and bacterial density. Temperature was significantly correlated with bacterial density, induction activity and biofilm thickness (P<0.05).The densities of bacteria in the biofilms of the two Pseudoalteromonas strains were significantly correlated with the induced activity. This present study shows that deep-sea bacteria exhibited good potential on temperature change to form the biofilms, and impacted larval metamorphosis.

Abstract:(Objective)(Method)Compare of the growth, the ratio of RNA/DNA,digestive enzyme and related immune enzyme activities in normal growth seahorse(8.57±0.61cm,1.51±0.38g) and slow growth seahorse(6.68±0.35cm, 0.81±0.14g)of Hippocampus erectus were studied at 110d raising, respectively. (Result)The results showed that the average daily gain, rate specific growth, condition factor and viscera index in the normal growth seahorse were significantly higher than that of the slow growth seahorse(P<0.05) , respectively.The normal growth seahorse grew more faster than that of the slow growth seahorse when the body length was 5.026cm. The amylase ,protease and lipase activity in normal growth seahorse were as the same tendency as that of the slow growth seahorse under different reaction temperatures (5 ℃, 15 ℃, 25 ℃, 30 ℃, 35 ℃, 45 ℃ and 55 ℃)and pH (2.0、3.0、4.0、5.0、6.0、7.0、8.0 and 9.0), however, the digestive enzyme activity of the former were much higher than that of the latter except amylase activity at 35~55 and protease activity at 5~25. ℃.The activities of ACP、AKP、T-AOC and SOD in normal growth seahorse were more 12.83%、48.21%、44.71%and 65.75% than that of the slow growth seahorse(P<0.05), respectively.The MDA of the normal growth seahorse was only 61.09% of that in the slow growth seahorse(P<0.05),and the ratio of RNA/DNA in the normal growth seahorse was higher 23.75% than that of the slow growth seahorse(P<0.05). (Conclusion) There were significantly different between in two growth status seahorse in growth, digestive enzyme and related immune enzyme activities.

Abstract:To investigate the effects of microplastics and phenanthrene on the growth, energy storage, stable isotope composition and stoichiometry of the discus fish (Symphysodon haraldi), here we set three microplastics concentrations (0, 100 and 1000 μgL-1) and two phenanthrene levels (0and 50 μgL-1), forming a total of six exposure combinations with three replicates per group for eight weeks. The results showed that: 1) Single exposure to microplastics or phenanthrene reduced the condition factor of the fish. The microplastics and phenanthrene in culture water had significant interaction with the hepatosomatic index of the juvenile discus fish, when the phenanthrene concentration was 50 μgL-1, 100 μgL-1 microplastics caused the hepatosomatic index of juveniles to increase. 2) The protein content of juvenile fish increased with the increase of phenanthrene concentrations. Microplastics and phenanthrene exposure had an interaction effect on the carbohydrate and crude fat contents of juvenile fish. When the phenanthrene concentration is 0 μgL-1, the increase in microplastics concentration would increased the crude fat content and reduced the carbohydrate content, but when the phenanthrene concentration is 50 μgL-1, the microplastics exposure would increased the crude fat and carbohydrate content. 3) The δ13C of juveniles increased with the increase of phenanthrene concentrations and decreased with the increase of microplastics concentrations. When co-exposed of microplastics and phenanthrene interacted with the δ15N value of juveniles, but the difference was not significant under different conditions. 4) Exposure to phenanthrene increased the N content and reduced the C/N of the fish. Co-exposed of both microplastics and phenanthrene had an interaction effect on the C and P content of juvenile fish: exposure to microplastics alone increased the C content and decreased the P content, when the concentration of microplastics is 50 μgL-1, phenanthrene exposure reduced P content. The results of this study suggest that exposure to microplastics and phenanthrene show no significant effect on the growth and survival of juvenile discus fish, but it might affect the energy storage status of the fish body, leading to changes in their stable isotope turnover and C, N and P stoichiometry characteristics and thus affecting the relative fatness and body quality of the discus fish. The results of this study can provide scientific basis for ecological risk assessment of microplastics and PAHs in fishery water environment.

Abstract:In order to screen the high-quality combination of donor and host mussels, explore the difference and correlation on the growth traits of different pearl mussels after graft operation, compare the difference of the pearl-forming percentage and size in each combination, by using Hyriopsis cumingii, Hyriopsis schlegeli, Kangle clam[Hyriopsis cumingii(♀) x Hyriopsis schlegeli(♂)] and Cristaria plicata as donor and host mussels respectively, 16 pearl mussels combinations were obtained. In addition, 4 species pearl mussels without graft operation were taken as control group. 16 combinations and 4 control groups were compared by measuring the growth traits (body weight, shell length, shell height and shell width) at the first year after grafting, and as the same time the correlation of growth traits of each combination was analyzed. The number and size of non-nucleated pearl in each combination was measured, the pearl formation percentage and roundness were calculated and the difference among different combination was analyzed. The results showed that the growth traits were greater than corresponding values of control group when H.cumingii, H.schlegeli were host mussels. However, the growth of C.plicata groups was inhibited; Except for the C-C group, the correlation coefficient between shell length and body weight was the largest (0.824~0.972) among each group. The correlation coefficient between shell width and body weight of C-C group was largest(0.782); The combinations among H.cumingii, H.schlegeli and Kangle clam had higher pearl formation percentage (98.75%～100%). And the pearl formation percentage of S-S, S-C and C-C groups reached 100%. The pearls when H.cumingii, H.schlegeli were host mussels were larger in size and rounder in shape. There was a significant positive correlation between the size of pearls and the percentage difference of diameters in all pearl combinations. The results showed that S-S、S-C、C-C groups worked best. The results provided an important basis for the exploration of the correlation between the growth traits of different pearl mussels and the comparison of the pearl-forming rate and size of the seedless pearls produced.

Abstract:Taking Enteromorpha prolifera from Zhejiang coast as raw material, continuous extraction and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) were used to analyze the content of aluminum in Enteromorpha prolifera from different sea areas. The distribution and speciation of aluminum in Enteromorpha prolifera were investigated, and the extraction conditions were optimized. The optimum extraction parameters were as follows: crushing Enteromorpha prolifera to 20-30 meshes, HCl and NaOH concentration was 1 mol.L_^-1, and the extraction temperature was 60℃. The results showed that the total aluminium content in Enteromorpha prolifera ranged from 1585.25 mg.kg_^-1 to 1776.48 mg.kg_^-1, mainly in the form of stable aluminium and active aluminium. The stable aluminum is mainly soluble polysaccharide-bound aluminum (Al_osu), small molecule protein aluminum (Al_pros), alginate-bound aluminum (Al_swg), macromolecule protein aluminum (Alpro), and fibrous aluminum (Al_ofi), accounting for 1.77%~2.70%, 12.65%~17.11%, 39.76%~42.08%, 20.31%~22.23%, 11.99%~14.51% of the total aluminum, respectively; the active aluminum is mainly hydroxyl aluminum(Al(OH) _²⁺, Al_³⁺), AlF and Al_ofi. Soluble organic aluminium (Al_osm) accounts for 8.57% to 11.38% of total aluminium. These results may provide scientific basis for the edible safety of Enteromorpha prolifera and the standard formulation of aluminum.

Abstract:Data-limitation is a difficult issue in fishery stock assessment and management. Base on length frequency data of Parargyrops edita collected from otter trawl survey in the Beibu Gulf in 2006–2018, we used length-based Bayesian biomass (LBB) method to estimate population parameters, namely asymptotic length (L∞), optimal length-at-first-capture (Lc_opt), relative natural mortality (M/k), and relative fishing mortality (F/k). The L∞ was estimated to be 21.0 cm, Lc_opt to be 12.6 cm, and M/k, F/k, Z/k and E to be 1.49, 3.65, 5.15, and 0.67, respectively. L∞ and Lc_opt showed the similar downward trend, and fish growth tended to be increasing. The Lc_opt and exploitation rate estimated by LBB were close to those estimated by independent full stock assessments. This case study suggested that if the length frequency represents length composition of a stock, the estimation by LBB will perform properly, and the method based on LBB can provide informative reference for fishery stock assessment under the data-limited conditions.

Abstract:Abandoned, lost or otherwise discarded fishing gear (ALDFG) is one of the most serious hazards of marine ecology and fisheries. The problems triggered by ALDFG have attracted increasing attention from many countries and international organizations around the world. This paper reviews the harm of ALDFG to marine ecology and fisheries, the primary causes of ALDFG, the steps proposed by states and relevant international organizations to remove ALDFG, and the commonly used ALDFG survey and evaluation methods in recent years. It has been found that in recent years, most of the studies on ALDFG used statistical models to quantify ALDFG, or combined with statistical tests to assess the harmfulness of ALDFG (ghost fishing) and to evaluate the ecological and economic benefits of clearing ALDFG, etc. This paper suggests that: (1) the questionnaire survey and underwater field survey should be used to assess the amount and harm of ALDFG in the national jurisdictional area, and analyze the trajectory of ALDFG by ocean dynamics models combining with the hydrodynamics of fishing gear; (2) the new materials should be developed and the design of fishing gear and ancillary gear should be improved to reduce the ALDFG；(3) the physical change in the process and the change of ghost fishing capacity of underwater ALDFG should be studied by field survey；(4) the positive role to the marine ecological system diversity and fishery resources should be studied after the underwater ALDFG removed, and the social and economic benefit should be evaluated by the economic model analysis after the underwater ALDFG removed.

Abstract:Individual length frequency is an important structural feature of fishery resource population. Generally, analytical indicators such as average individual body length or average body weight are used in studies, which is difficult to fully reflect the population composition differences with multiple age structures and different individual growth rate. These study analyzed the temporal and spatial variation of individual size composition of Oratosquilla oratoria, according to the bottom trawl survey data collected in October 2016 and January, May and August 2017 in the marine area of Shandong, using the Finite mixture model to analyzed the length frequency distribution characteristics of individual size of O. oratoria with different time and depths. The research shows that, the O. oratoria in the marine area of Shandong can be distinguished as high and low age cohorts except autumn, and there is a certain difference in the distribution of male and female body length. The proportion of female O. oratoria in the low age cohorts decreased first and then increased from winter to summer, while the proportion of male O. oratoria decreased gradually. In terms of different depths, the individuals in the low age cohorts are mainly concentrated in the offshore areas, and the proportion decreases gradually from offshore to the open sea. The distribution of age cohorts showed seasonal differences. In spring, the proportion of O. oratoria in high age cohort was the largest in the offshore area, and the proportion gradually decreased from offshore to open sea. The percentage of O. oratoria in the high age cohort in summer was the highest in water depth of 20-30 meters. The percentage of O. oratoria in the high age cohort in winter increased gradually from offshore to open sea. This paper preliminarily analyzed the temporal and spatial distribution of O. oratoria in different age cohorts in the marine area of Shandong, and the research results are of great significance for in-depth understanding of population distribution dynamics and scientific fishery management.Previous studies on the size composition of O. oratoria were only grouped according to the size of body length, ignoring the differences in the growth rate among individuals of different O. oratoria, and there might be overlap of body length frequency among different age groups. Therefore, a Finite Mixture Model was used in this study to divide the body length frequency of O. oratoria into subgroups of different sources (different age groups) according to the statistical test results. This is a new exploration of the distribution of O. oratoria resources. In future studies, the proportion of different age cohort obtained by the Finite Mixture Model can be used to infer the spawning area of O. oratoria. Meanwhile, the distribution of different age cohorts of O. oratoria can be studied in depth by combining Lipofuscin analysis. It is of great significance to fully understand the temporal and spatial changes of O. oratoria distribution, and is helpful for the scientific development and management of O. oratoria resources.

Abstract:Based on the1840 samples of Japanese Common Squid (Todarodes pacificus) collected during January to March in the Spring season in the La Ni?a year of 2018 in the East China Sea, the fisheries biological characteristics of T. pacificus was studied. The result indicated that the mantle length (ML) range was from 92 mm to 270 mm and 103 to 267 mm with a dominated concentration in180 mm to240 mm and 140 mm to 220 mm accounting for about 71.44 and 89.31percentages for females and males, the body weight (BW) range was from 21 g to 453 g and 21 g to 465g with a dominated concentration in120 g to270 g and 60 g to 180 g accounting for about 66.54 and 81.26 percentages for females and males, respectively. The ration of the somatic body weight (SBW) to BW ranged from 21.89 to 87.76 percentages with an average of 49.14 percentages. There was no significant difference between the BW and SBW growth in sex, and the relationships between the ML to BW and ML to SBW were both best described by the power functions by the result of Akaike’s information criterion (AIC). The ration of females to males was 1:1.255, and the samples were most composed of maturity individuals accounting for about 50.85 and 54.81 percentages for females and males. The feeding stage were mainly in 1 and 2 grade accounting for 64.24 percentages all of the specimens and the prey was mainly composed of squids, pelagic fishes, mollusc and crustacean and so on. It seemed that the fisheries biological feature of T. pacificus was affected by La Ni?a year with a decrease in the body size, a faster growth speed and advanced gonad maturity stages.

Abstract:GnIH (gonadotropin inhibitory hormone) has been proven to be a hypothalamic neuropeptide that regulates the reproductive negatively, which is related to reproduction. In this study, the full-length cDNA sequences of gnih and gnihr3 genes of diploid red crucian carp and allotriploid crucian carp were obtained by PCR and RACE technology. Real-time PCR was used to analyze the expressions of gnih and gnihr3 genes in different tissues of different ploidy Cyprinids. The results showed that the expression level of gnih gene in the hypothalamus of red crucian carp was higher than that of allotriploid crucian carp; the gnihr3 gene was expressed differently on the hypothalamic–pituitary–gonad axis (HPG). Nevertheless, it was noteworthy that regardless of non-breeding or breeding season the expression of gnih in the hypothalamus from red crucian carp was higher than that of allotriploid crucian carp. Simultaneously, the expression level of gnihr3 gene in hypothalamus and pituitary of red crucian carp was higher than that of allotriploid crucian carp, but the expression of gnihr3 in the ovary of allotriploid crucian carp was higher than that of red crucian carp. Through in situ hybridization, the locations of gnih and gnihr3 in brain or pituitary of different ploidy fishes were analyzed. Strong hybridization signals of gnih could be detected in Npp, Npo, NLT in the brain of red crucian carp and allotriploid crucian carp. Strong hybridization signals of gnihr3 were located mainly in the PPD and RPD regions of the pituitary, and weak hybridization signals were distributed in NH and PI regions. Meanwhile, the signal of gnihr3 hybridization of allotriploid crucian carp in the pituitary was much weaker than that of red crucian carp. The results showed that gnih is mainly expressed in the hypothalamus, combining with the receptors distributed in HPG widely and acting through multiple pathways, which participate in the regulation of gonad development of different ploidy cyprinids through multiple ways. There are differences in the expression of gnih and gnihr3 mRNA in different ploidy fish tissues. This study provides molecular evidence for sterility of allotriploid crucian carp, which is important for fish reproduction and genetics breeding.

Abstract:The continental slope is a relatively steep transition zone between a low-gradient marine shelf and the deep seafloor. It has unique geographic ecological enviroment and actively exchange of energy and matter fluxes. Based on the survey data of fishery resources and marine ecological environment in the continental slope of northern South China Sea during 2015-2016, we developed a mass-balance model, which consists of 22 functional groups, using Ecopath with Ecosim software. Based on the model, we analyzed the trophic structure, energy flow and system attribute. The fractional trophic levels of these ecological groups ranged from 1 to 4.47, with the highest TLs reached by dolphins in the food-web system. The Keystone Index (KSi) analysis indicated that the mesozooplankton and Sthenoteuthis oualaniensis are considered as key species in the system. The energy flow of this ecosystem was mainly dominated by detritus food chain, which accounts for 52% of the energy source. Using network analysis, the system network was mapped into a linear food chain and 6 integrate trophic levels were found with a mean transfer efficiency of 21.94%, of which 21.26% from primary producer and 22.39% from detritus within the ecosystem．The results suggest that the continental slope of northern South China Sea ecosystem has a high ecological conversion efficiency.

Abstract:In order to know the spatial and temporal distribution of fishery resource and their relations with the environment in island and reef area of Ma’an Archipelago, BioSonics DT-X echosounder was used to conduct three acoustic surveys with a trawl sample in December 2016, March and May 2017. The results showed there were 46, 32 and 43 species estimated respectively in December 2016, March and May 2017, the average abundance density were 2.7×104 ind /km2, 1.98×104 ind /km2 and 1.45×104 ind/km2, and the average biomass density were 0.38 t/km2, 0.42 t/km2 and 0.34 t/km2. The fish abundance density decreased gradually over 3 times, the biomass density and biomass were the highest in March, followed by December and May. There was no significant linear relationship between depth and resource density, which were the highest at the bottom layer, followed at middle layer and the least value at surface layer. There was a significant positive correlation between the abundance density of the bottom layer and the silty content of the sediment (R2>0.75). There was no significant linear relationship with fishery abundance density and temperature and salinity of each month, and there was significant linear relationship with dissolved oxygen (R2=0.72) in the nearly reefs area, where the fishery abundance density was much higher than that in the far reefs. There was a significant linear relationship between fishery abundance density and temperature (R2=0.91), and the linear correlation with the dissolved oxygen was weak (R2=0.63), and there was no significant linear relationship with the salinity. The research confirmed that the acoustic method showed good effects in island and reef area of Ma’an Archipelago of fishery resources assessment, providing the scientific basis and realistic foundation to further study the effect and assessment of island and reef and artificial reef area.

Abstract:Brook trout (Salvelinus fontinalis) belongs to Salmoniformes and Salmonidae. It is native to northeastern North America with fast growth rate and high feed efficiency. Since it was introduced into China, it has become an important cultured species in cold-water. In order to study the population genetic structure and germplasm resource status of the introduced S. fontinalis population, 108 1 pairs of tetranucleotide repetitive microsatellite primers were designed by screening the transcriptome data of S. fontinalis. A total of 200 pairs were selected for primer synthesis, and 111 microsatellite markers with good specificity and high amplification efficiency were obtained through PCR amplification. Twenty-seven pairs of microsatellite primers were selected and used to analyze the polymorphism and genetic diversity of the introduced and cultured populations of S. fontinalis. The results were shown as fellows: a total of 171 alleles were detected in 27 microsatellite markers in two populations. The polymorphism information content (PIC) ranged from 0.426 0 to 0.877 4, with an average of 0.673 1, of which 23 loci were highly polymorphic (PIC ≥ 0.5). The average number of alleles (Na) was 5.555 6 and 4.444 4, the average number of effective alleles (Ne) was 3.914 5 and 3.108 2, the average observed heterozygosity (Ho) was 0.356 2 and 0.265 0, the average expected heterozygosity (He) was 0.700 2 and 0.621 0, and the average PIC was 0.640 9 and 0.555 5, respectively. The genetic parameters of the introduced population were tested by paired sample t test. The results showed that the five genetic diversity parameters of the cultured population were significantly or extremely significantly lower than those of the introduced population, indicating that although the PIC of the cultured population was still at a high polymorphic level (PIC ≥ 0.5), serious allele enrichment had occurred after multiple generations of self-breeding. Using a test of the Hardy-Weinberg principle (χ2 test) and Bonferroni calibration, all except 8 and 4 loci had deviated equilibrium in the introduced and cultured populations respectively, and most loci were heterozygote deficiency. There was high genetic differentiation (Fst=0.164 2), genetic similarity coefficient was 0.582 2 and genetic distance was 0.540 9 between the two populations, which indicated that there was significant genetic differentiation between introduced and cultured populations. These polymorphic markers may also be used in future studies of population genetics, linkage mapping and assisted breeding in S. fontinalis.