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月刊，1984年创刊
主管：内蒙古自治区教育厅
主办：包头医学院
主编：赵云山
特邀主编：高长青
编辑出版：包头医学院学报编辑部
国际刊号：ISSN 1006－740X
国内刊号：CN 15－1182/R
邮发代号：16-292

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2020 Vol. 39, No. 2 Published: 2020-03-25

Research and Application Overview and Specific Topic

Research and Application

	151	Cloning and Expression of Interleukin 21 Gene in Bastard Halibut Paralichthys olivaceus
		XUE Tingting, ZHENG Jinhui, ZHOU Mi, PAN Baoping, SUN Jinsheng, GAO Hong
		DOI: 10.16378/j.cnki.1003-1111.2020.02.001
		The coding sequence of interleukin-21 (IL-21) gene was cloned and expressed in bastard halibut Paralichthys olivaceus by using transcriptome sequencing data and PCR technology, and analyzed by bioinformatics analysis. The results showed that the open reading frame of IL-21 gene was 429 bp, encoding 142 amino acids with a molecular weight of 16.0 ku, and had a 19 bp signal peptide sequence at the N-terminal. Molecular phylogenetic tree indicated that IL-21 protein of bastard halibut had the closest relationship with IL-21 of perch Lates calcarifer and Stegastes partitus. Real-time fluorescent PCR revealed that IL-21 gene was expressed in all seven healthy tissues of bastard halibut, with the maximal expression level in liver. The expression of IL-21 was found to be up-regulated in head kidney and spleen of bastard halibut immunized with the extracted lipopolysaccharide from Edwardsiella tarda, indicating that IL-21 was involved in the immune response induced by lipopolysaccharide. When MyD88 gene was silenced by RNA interference, the expression of IL-21 was down-regulated, and the expression of MyD88 and IL-21 genes began to increase gradually in the bastard halibut immunized with the extracted lipopolysaccharide from E. tarda, indicating that that IL-21 is related to MyD88 pathway.
		2020 Vol. 39 (2): 151-159 [Abstract] ( 385 ) HTML (1 KB) PDF (16396 KB) ( 454 )

	160	In Vitro Effect of Alcohol Extracts of 5 Traditional Chinese Medicines on Leukocyte Immune Activity in Peripheral Blood of Nile Tilapia
		CHENG Min, LI Zhongqin, ZHAI Shaowei, LAI Xiaojian, YANG Qiuhua, JIANG Xinglong
		DOI: 10.16378/j.cnki.1003-1111.2020.02.002
		Chinese gall (Galla Chinensis), Chinese pulsaiilla root (Radix Pulsatillae), garden burnet root (Radix Sanguisorbae), fructus chebulae (Terminalia chebula), and giant knotweed rhizome (Rhizoma Polygoni Cuspidati) were powdered and sieved through a 160 mesh sieve, and then mixed with 60% aqueous solution of ethanol at the ratio of material to liquid 1∶10,finally ultrasonicated by an ultrasonic pulverizer for 1 hour. The filtrate was collected by filtration through a filter paper, and concentrated in a multi-sample parallel evaporator to obtain a Chinese medicine extract. About 0.5 mL of blood was collected from the caudal vein of Nile tilapia (Oreochromis niloticus) using a sterile syringe with 0.2 mL of anticoagulant, and mixed with L-15 cell medium at a ratio of 1∶9 by volume to form plasma. The Chinese herbal medicine extract was incubated with the Chinese herbal medicine extract alone and in combination and the effects of Chinese herbal medicine extract on the respiratory burst activity and leukocyte phagocytic activity in peripheral blood leukocytes of Nile tilapia were determined by nitrogen blue tetrazolium reduction method and flow cytometry. Single use of Chinese gall, Chinese pulsaiilla root, garden burnet root, fructus chebulae, and giant knotweed rhizome was shown to lead to significantly enhance the leukocyte oxygenation burst activity by 128.68%, 123.96%, 28.37%, 44.44%, and 78.93%, and the phagocytic rate elevate by 44.04%, 44.66%, 95.00%, 10.35% and 64.93%, respectively. In the double-use experiment of two traditional Chinese medicines, the combination showing synergistic effect on the leukocyte oxygen respiratory burst activity was Chinese pulsaiilla root + garden burnet root, with the combined respiratory burst index of 1.28. There were 4 combinations showing synergistic effects on phagocytic activity of leukocyte, including Chinese pulsaiilla root + giant knotweed rhizome, fructus chebulae + giant knotweed rhizome, Chinese gall + giant knotweed rhizome, and Chinese pulsaiilla root + fructus chebulae, with the phagocytic combined index of 11.45, 6.20, 3.03, and 1.06, respectively.
		2020 Vol. 39 (2): 160-167 [Abstract] ( 234 ) HTML (1 KB) PDF (14430 KB) ( 196 )

	168	Growth and Single Nucleotide Polymorphism Loci Analysis of Myostatin Gene in ENU Mutagenesis Grass Carp Family
		WANG Chenglong, CHEN Jie, JIANG Xiayun, ZOU Shuming
		DOI: 10.16378/j.cnki.1003-1111.2020.02.003
		Juveniles of mutagenesis grass carp (Ctenopharyngodon idellus) by N-ethyl-N-nitrosourea (ENU) in four families were reared in a 6 m × 4 m × 1.5 m cement pond for 175 days to compare the growth. Significant comparisons, partial correlation analysis, and factor analysis statistical methods were used to analyze body weight, total length, body length, head length, body depth, caudal peduncle length, caudal peduncle height, and body width and single nucleotide polymorphism (SNP) loci of myostatin (MSTN) gene MSTN1 and MSTN2 genes in families with significant differences screened by two-way sequencing. There was significantly better growth in family 4 than that in family 3, with significantly higher 8 characters in family 4 than in the other families (P<0.05). The partial correlation analysis of the relationship between the morphological traits and body weight indicated that there were correlation coefficient of 0.357 between total length and body weight, 0.619 between body length and body weight, 0.608 between caudal peduncle length and body weight, and 0.396 between body width and body weight in family 1; there were correlation coefficient of 0.348 between total length and body weight, 0.360 between body length and body weight, 0.687 between head length and body weight, and -0.384 between body width and body weight in family 2; in family 3 there were correlation coefficient of 0.529 total length, 0.449 body length, -0.351 caudal peduncle length, and 0.384 caudal peduncle height; and in family 4 there were 0.629 total length, 0.543 body length, and 0.590 body width, showing the significat difference in growth between family 4 and family 3. For MSTN1, 465 nt C/G and 467 nt G/A in family 3, and 465 nt C/G in family 4 were found missense mutations; For MSTN2, 912 nt C/T in family 3 and family 4 was found synonymous mutation, 1027 nt G/A in family 3,and 366 nt A/G and in family 4 were found missense mutations, and SNP sites were found in both noncoding regions 1390 nt A/T and 1401 nt G/A in both families. The findings indicate that the SNPs of MSTN1 and MSTN2 genes are closely related to the growth traits of ENU mutagenesis grass carp.
		2020 Vol. 39 (2): 168-174 [Abstract] ( 174 ) HTML (1 KB) PDF (12833 KB) ( 123 )

	175	Effects of Different Dietary Carbohydrate Sources on Growth Performance, Body Composition and Digestive Enzyme Activities of Juvenile Green Crab Scylla paramamosain
		XU Mingzhu, ZHANG Qin, DONG Lanfang, TONG Tong, XIE Da, SU Qiong
		DOI: 10.16378/j.cnki.1003-1111.2020.02.004
		Juvenile green crab Scylla paramamosain with average body weight of (0.012±0.000) g were reared in plastic buckets (20 cm in diameter and 20 cm in depth) with 1—2 cm fine sand and 5 cm² tiles at bottom and fed diets containing seven carbohydrate (CBH) sources (glucose, sucrose, dextrin, tapioca starch, corn starch, gelatinized tapioca starch, and gelatinized corn starch) for 3 weeks to investigate the effects of dietary CBH sources on growth performance, body composition and digestive enzyme activities of green crab. The results showed that the growth performance of the juvenile was significantly influenced by different CBH sources (P<0.05), the maximal weight gain rate (WGR) and specific growth rate (SGR) in the green crab fed gelatinized tapioca starch, significantly higher than those in other groups (P<0.05) and with the descending order of WGR and SGR as: gelatinized cassava starch > gelatinized corn starch > cassava starch > corn starch > dextrin > sucrose > glucose. The minimal survival ratio (SR) was observed in glucose group, significantly lower than that in the other groups (P<0.05). The body composition analysis indicated that dietary CBH sources had significant effects on body ether extract content and body protein contents (P<0.05), without significant differences in moisture, and ash content (P>0.05). There were significant effects of different dietary CBH sources on digestive enzyme activities in the green crab juveniles (P<0.05), indicating that green crab had higher bioavailability of macromolecule carbohydrate sources than that of micromolecule CBH sources. It is concluded that gelatinized cassava starch is the optimal carbohydrate sources for green crab juveniles.
		2020 Vol. 39 (2): 175-181 [Abstract] ( 230 ) HTML (1 KB) PDF (11033 KB) ( 611 )

	182	Effects of Salinity Regulation Methods on Establishment of Marine Biological Flocculation Culture System
		WU Huifang, LUO Guozhi, TAN Hongxin, MENG Haoyan
		DOI: 10.16378/j.cnki.1003-1111.2020.02.005
		Effects of three salinity addition methods on culture flocs and the start-up efficiency of bioflocculation system were investigated in nine cylindrical aquaculture buckets with a volume of 100 L and with eel feed as raw materials, in which salinity was adjusted to 30 at the beginning of the experiment in the first group, the salinity was increased by 5 degrees every day after the end of the depression, adding 1 degree every 3 hours in the second group, and the salt was added into cultured freshwater biological flocculation system according to the way of adding salt in the second group in the third group. After startup, the removal efficiency of 10 mg/L ammonia nitrogen in three treatment groups was monitored.The results showed that the contents of ammonia nitrogen and nitrite nitrogen in the second and third groups were decreased to low level before the salinity was adjusted to 30 in first group. During the culture period, there was better settleability of flocs in the second and third groups than that in the first group. The high-throughput sequencing revealed that Flavobacteria was the dominant class in the biological flocculation system with salinity of 30, and Sphingobacteria was the dominant class in the flocculation system with initial salinity of 30. Actinomycetes is the dominant class in the biological flocculation system of freshwater culture and redomestication into seawater. Leptobactrrium and norank_f_Segniliparacea were the dominant genus of marine biological flocculation system with salinity of 30.It was concluded that the second salt regulation method was the most beneficial to cultivate marine biological flocculation system combined with the continuous monitoring of the removal effect of ammonia nitrogen in the three treatment groups after start-up, without significant difference (P>0.05).
		2020 Vol. 39 (2): 182-192 [Abstract] ( 197 ) HTML (1 KB) PDF (23787 KB) ( 136 )

	193	Effect of Three Types of Water Quality Control Methods on Sediment Enzyme Activity in Sea Cucumber Pond
		WEI Yanan, ZHANG Dongsheng, LIN Qing, SUN Guangwei, LEI Zhaolin, ZHANG Jinyuan, GUO Chao, CHEN Jifeng, ZHOU Wei
		DOI: 10.16378/j.cnki.1003-1111.2020.02.006
		This paper reported the annual changes in the activities of amylase, protease, alkaline phosphatase and dehydrogenase in sea cucumber sediments under three types of water quality control methods from October 2015 to September 2016. The results showed that under the three water quality control methods, the annual change in amylase activity in the pond sediments was 0.126—0.880 mg/g, the annual mean value (0.410±0.180) mg/g, the annual change of protease activity was 0.024—0.472 mg/g, the annual mean value (0.190±0.103) mg/g, the annual change in alkaline phosphatase activity was 0.068—1.042 mg/g, the annual mean value (0.340±0.196) mg/g, and the annual change in dehydrogenase activity was 12.092—52.794 mL/g, annual mean value (26.980±8.295) mL/g.The activities of protease, alkaline phosphatase and dehydrogenase in the pond sediments under the three water quality control methods were the highest in the natural tidal water quality control method ponds with the largest variation range.The mean value of amylase activity was the lowest in natural ponds and the highest in the water regulating machine system ponds.This is related to the lowest organic matter in the water regulating machine system ponds, the highest content of organic matter in the natural pond, and the highest bacterial diversity and the highest number of fungi in the water regulating machine system ponds. This indicates that the water regulating machine system can quickly remove the organic compounds of nitrogen and phosphorus from the sediments, which is beneficial to the normal material circulation of the pond. In this paper, from the perspective of sediment enzyme activity, the mechanism of the difference between the effect of the water regulating machine system and the other two water quality control methods was discussed.
		2020 Vol. 39 (2): 193-199 [Abstract] ( 143 ) HTML (1 KB) PDF (12635 KB) ( 122 )

	200	Structural Characteristics of Intestinal Microbiota in Black Rockfish Sebastes schlegelii during Early Life Stage
		JIANG Yan, CAO Yanan, LIU Xuezhou, XU Yongjiang, LI Dejun, SHI Bao, WANG Bin
		DOI: 10.16378/j.cnki.1003-1111.2020.02.007
		V3 and V4 variable regions of 16S rDNA of intestinal microbiota were sequenced in black rockfish Sebastes schlegelii larvae and juveniles with 1, 9, 20, 54 and 95 day after hatching (DAH) using Illumina MiSeq PE300 system. A total of 1039 operational taxonomic units (OTU) and 667 genera were obtained. At the genus level, there were higher microbial abundance and mean value (higher than 1%) (86%) in intestinal microbiota in wild fish than that in juvenile stage (73.5%), with the most abundances dominant genus of Acinetobacter (26.2%—45.3%), and followed by genus Brevibacillus. Meantime, the combined analysis of shared microflora revealed that there were 11 core microbiota. With growth of the larvae and juveniles, successional abundances for Bacillus, Brevibacillus, Acinetobacter and Rhizobium, belong to the core microbiota, were increased firstly and then declined rapidly, the maximal abundances of these four genera were all appeared on 54 DAH. However, Vibrio as one of the core microbiota, with abundances of 0.37%—12.41%, showed the opposite trend during the early life stage, with the minimal value on 54 DAH. There were only 14 shared genera in intestines between larvae and juveniles and wild ones, the minimum abundance of Brevibacillus and Massilia in intestine of larvae and juveniles being 9 times and 32 times as the maximum value of these two genera in wild fish, showing the obvious difference. The findings will provide the theoretical reference for the regulation of intestinal physiological health during the life stage.
		2020 Vol. 39 (2): 200-208 [Abstract] ( 204 ) HTML (1 KB) PDF (15907 KB) ( 145 )

	209	Growth and Reproductive Biology of Chinese Spined Loach Cobitis sinensis
		YANG Jun, HE Xingheng, SUN Zhiyu
		DOI: 10.16378/j.cnki.1003-1111.2020.02.008
		In July 2012 and May 2013, 70 Chinese spined loach Cobitis sinensis were caught in traps and electrical fishing in Donghe River of Wangcang County, Guangyuan City, Sichuan Province and fixed in 10% formalin solution and then stored in 5% formalin solution, and another 43 samples were transported to the laboratory with plastic bag oxygenation. After routine biological measurements, the viscera of the tested fish were taken out, and the intestinal length, eviscerated weight and gonad weight were measured to investigate the growth and reproductive biology of the fish including food item analysis, male and female identification and sperm longevity. The Chinese spined loach had body length (L) of 34.92—102.85 mm, body weight (m) of 0.34—9.84 g, and eviscerated weight of 0.31—8.09 g, and was divide into 5 age classes, determined by vertebra, with dominant 2—4 age classes. The Chinese spined loach had good growth before 3 year old, low growth afterwards, with function between body length and body weight of m₁=0.00001215L^2.896, r²=0.939, nearly isometric growth. The relative condition factor was generally found to be less than 1, without significant difference in Fulton condition factor between female and male (P>0.05), even though smaller in males than in females. For the over 1 year old loach, however, there was slightly larger Clark condition factor in males than that in females. The Chinese spined loach had sexual ratio (♀∶♂) of 1∶1.69, and maturity at two years old age. The sperm survived for 14 seconds in distilled water, and longevity of the sperm was shown to be increased first and then decreases with the increase in NaCl concentration, with the maximal longevity (184 s) at NaCl concentration of 0.25%. The Chinese spined loach had absolute fecundity of 427—4047 eggs per female, with mean value of 1949.82 eggs, and relative fecundity of 107.56—566.09 eggs/g, with mean value of 356.07 eggs/g. The peak period of spawning was observed from mid-June to mid-August, spawning in batches, and roughly the same fecundity each batch, and the zygote is demersal and slightly viscous.
		2020 Vol. 39 (2): 209-217 [Abstract] ( 334 ) HTML (1 KB) PDF (14074 KB) ( 211 )

	218	Growth of Hybrid F₁ of Burnt-end Ark Scapharca broughtonii between Chinese and Korean Populations
		WU Yingying, LIU Tong, WANG Yingjun, ZOU Yan, SONG Aihuan, LIU Hongjun
		DOI: 10.16378/j.cnki.1003-1111.2020.02.009
		Four groups of hybrid F₁ of burnt-end ark Scapharca broughtonii, including Chinese population ♀×Korean population ♂ (HZ-1), Chinese population♀ ×Chinese population ♂ (ZZ), Korean population ♀×Chinese population ♂ (HZ-2), and Korean population ♀×Korean population♂ (HH), were established by reciprocal cross between Chinese population and Korean population. The juvenile shellfish were reared in a cage in the sea area (N 35°32′41.85″, E 119°41′29.49″) and sampled at the ages of 4, 5, 7, 9, 11 and 13 months to evaluate growth, survival and heterosis of juvenile shellfish. The variation trend of heterosis of shell length, shell height, shell width and wet body weight was found to be the same in HZ-1, with increase with the increase in age at the early stage, and the maximal at the age of 11 months (heterosis rate of 7.73% in shell length, 4.80% in shell height, 8.84% in shell width, and 27.44% in wet body weight, the maximal heterosis rate in body weight), and then significant decrease at the age of 13 months. The 7-month old and 11-month old HZ-2 had the basically positive values of the heterosis rate in the 4 traits, with the maximal value of 2.61%, and with heterosis rates in survival of 5.89% in HZ-1 and 4.15% in HZ-2, showing higher in HZ-1 than in HZ-2. Comprehensive analysis indicated that HZ-1 as an ideal breeding candidate had obvious heterosis in growth performance and survival rate. The findings provide theoretical support and technical reference for the development and utilization of germplasm resources and cross breeding of burnt-end ark.
		2020 Vol. 39 (2): 218-223 [Abstract] ( 155 ) HTML (1 KB) PDF (9203 KB) ( 114 )

	224	Microsatellite Screening and Genetic Diversity Analysis of Gudgeon Pseudohemiculter dispar in Pearl River Basin
		SU Yuling, LI Min, YANG Yongchun, LIU Jiahao, LI Zhenhai, RUAN Huiting, DAI Jiage, LIU Li, ZOU Keshu
		DOI: 10.16378/j.cnki.1003-1111.2020.02.010
		Thirty-six polymorphic microsatellite markers were screened in gudgeon Pseudohemiculter dispar (Peters 1880), a small economical wild fish distributed in various freshwater drainages of south Yangtze River, by RAD-Seq technology, including 29 high polymorphism (polymorphic information content, PIC>0.50), 6 moderate polymorphism (0.25<PIC<0.50), and 1 low polymorphism (PIC<0.25). Six highly polymorphic microsatellite loci were used to analyze the genetic diversity and genetic differentiation of 8 populations of gudgeon in Pearl River basin including Beijiang, Guijiang, Duliujiang, Rongjiang, Zuojiang, Youjiang, Qianjiang and Yujiang, with alleles of 98.17, observing allele number of 12.2713, effective allele number of 6.0575, observed heterozygosity of 0.5389, expected heterozygosity of 0.7679, Shannon′s Information Index of 1.8974 and PIC of 0.7379, indicating that there was high level of genetic diversity among 8 populations of gudgeon in Peal River basin. The analysis of molecular variance showed that average populations differentiation (Fst) was 0.1028 and the inbreeding coefficient (Fis) was 0.2987, which implied that 10.28% genetic variation was between populations and 89.72% variation within population, showing the moderate level of genetic differentiation. The gene flow varying from 1.0075 to 4.7308 suggested that 8 populations be stable enough to resist genetic drift. The findings provided scientific basis for genetic resource preservation and management in gudgeon.
		2020 Vol. 39 (2): 224-233 [Abstract] ( 167 ) HTML (1 KB) PDF (16374 KB) ( 125 )

	234	Community Structure and Spatio-temporal Variation of Fish in Liuxi River Reserve
		WU Qian, LI Chao, GAO Tianyang, LI Wei, ZHANG Wenjun, WANG Junjie, ZHAO Jun
		DOI: 10.16378/j.cnki.1003-1111.2020.02.011
		Fish were sampled at 3 monitoring sites in Spinibarbus hollandi National Aquatic Germplasm Reserve in Liuxi River in winter (December 2017), spring (April 2018), summer (June 2018) and autumn (October 2018) by the combination of gill nets, trap cages and electric fishing in order to understand the structure of fish community in Liuxi River National Aquatic Germplasm Resources Reserve and the changes in fish community diversity in different river sections and seasons. During this survey, 57 species of fish were collected, belonging to 5 orders, 14 families and 50 genera, including 43 species in Cypriniformes, 6 species in Perciformes, 5 species in Siluriformes, 2 species in Synbgranchiformes and 1 species in Cyprinodontiformes. The relative importance index (IRI) showed that Nile tilapia Oreochromis niloticus, Acheilognathus tonkinensis and common carp Cyprinus carpio were the annual dominant species from 2017 to 2018. The Shannon-Wiener (H′), richness (D) and evenness (J′) revealed that there were the maximal species diversity and uniformity of fish communities in downstream, and that there were higher species diversity, richness, and uniformity of fish communities in summer than those in the other seasons. The Jaccard′s similarity index between the monitoring sites showed that the composition of fish species in the upstream and midstream, and upstream and downstream were medium dissimilar and the midstream and downstream were moderately similar. The fish species composition was found to be medium dissimilar in spring and summer, spring and winter, summer and winter, summer and autumn and moderately similar in spring and autumn, autumn and winter. ABC curve analysis revealed that the fish community in spring, summer and winter was in a stable state, and in a state of moderate disturbance in the autumn.
		2020 Vol. 39 (2): 234-244 [Abstract] ( 226 ) HTML (1 KB) PDF (16633 KB) ( 208 )

	245	Analysis and Evaluation of Nutritional Composition in Muscle of Hybrid Grouper Epinephelus akaara♀×E. lanceolatus♂
		WU Shuiqing, LUO Huiyu, ZHENG Leyun, WU Huihuang, LIN Kebing, GE Hui, JIANG Shuangcheng, ZHANG Zhe, QIU Fengyan
		DOI: 10.16378/j.cnki.1003-1111.2020.02.012
		Approximate nutrient compositions, and levels of amino acid and fatty acid in muscle were analyzed and evaluated in hybrid grouper Epinephelus akaara♀×E. lanceolatus♂ with body weight of (182.84±29.35) g by route methods, and the national standard in order to verify the nutritional characteristics of the hybrid grouper. It was found that the hybrid grouper had muscular moisture of (74.07±0.71) %, lipid content of (21.52±0.78) %, crude protein content of (4.03±0.15) % and crude ash content of (1.29±0.07) %. Seventeen amino acids were detected from the muscle, with the total quantity of (19.88±0.15) %, essential amino acids (EAA) content of (8.64±0.13) %, delicious amino acids (DAA) of (7.64±0.16) %, essential amino acid index (EAAI) of 85.19, and the amino acid composition ratio accorded with the standard of FAO/WHO. There were 17 main fatty acids detected in the muscle of hybrid grouper, saturated fatty acid (SFA) content of (27.63±1.15) %, monounsaturated fatty acid (MUFA) content of (22.75±1.22) %, and polyunsaturated fatty acid (PUFA) content of (32.59±1.90) %, especially DHA+EPA accounting for (19.27±1.27) % in total fatty acids. The finding indicates that hybrid grouper is a kind of fish with high nutritive value and a potential aquaculture candidate.
		2020 Vol. 39 (2): 245-250 [Abstract] ( 170 ) HTML (1 KB) PDF (9457 KB) ( 175 )

	251	In Vitro Antibacterial Effect of Combination of Antimicrobial Agents against Pathogen Shewanella algae
		CAO Haipeng, YANG Lijun, CHEN Sijia, GUO Cheng, YANG Xianle
		DOI: 10.16378/j.cnki.1003-1111.2020.02.013
		The in vitro antibacterial activity of gentamicin sulfate and cefotaxime sodium against pathogenic Shewanella alage SFH3 isolated from Pacific white leg shrimp Litopenaeus vannamei with black spot disease was assayed in comparison with the six fishery antimicrobials, then the in vitro combined inhibitory effect of gentamicin sulfate and cefotaxime sodium was determined at different combined proportions by the tube double broth dilution method, and the in vitro combined bactericidal effect was further confirmed by time-kill curve assay in order to assess the potential of gentamicin sulfate and cefotaxime sodium in combination against aquatic pathogen S. alage SFH3. It was found that minimum inhibitory concentration (MIC) was 80 mg/L in gentamycin sulfate and 160 mg/L in cefotaxime sodium against the pathogen SFH3, significantly lower than thiamphenicol, doxycycline, oxolinic acid, sodium sulfamonomethoxine, sulfamethoxazole, and enrofloxacin hydrochloride. The combination of gentamicin sulfate and cefotaxime sodium showed synergistic inhibitory activities against S. alage SFH3 at combined proportions of 8∶2, and 7∶3 with MICs of 40 mg/L. In addition, 40 mg/L gentamicin sulfate and 80 mg/L cefotaxime sodium had synergistic bactericidal effect against the pathogen SFH3. This finding confirms that the combination of gentamicin sulfate and cefotaxime sodium can contribute to the in vitro antibacterial activity, which provides scientific reference with the drug control of aquatic pathogen S. alage.
		2020 Vol. 39 (2): 251-257 [Abstract] ( 196 ) HTML (1 KB) PDF (11861 KB) ( 110 )

	258	Genetic Polymorphism Analysis of Cytb and COⅠ Gene Sequences of Icefish Protosalanx hyalocranius and Neosalanx taihuensis in Lake Gaoyou
		LI Daming, SUN Wenxiang, XU Fei, TANG Shengkai, LIU Yanshan, GU Xiankun, LIU Xiaowei, ZHANG Tongqing
		DOI: 10.16378/j.cnki.1003-1111.2020.02.014
		The genetic diversity and genetic structure were analyzed in two populations of icefish Protosalanx hyalocranius and Neosalanx taihuensis in Lake Gaoyou by sequencing the Cytb and COⅠ genes in the mitochondrial DNA in order to understand the current situation of wild resources of the wild populations of icefish in the Lake Gaoyou. The full Cytb gene sequences (1141 bp) were obtained from 40 individuals of P.hyalocranius,14 variable sites were detected and 12 haplotypes were defined, with haplotype diversity of 0.871±0.031, and the nucleotide diversity of 0.00172±0.00019, showing a type of high haplotype diversity and low nucleotide diversity. The partial COⅠ gene sequences (630 bp) were obtained, 5 variable sites were detected and 6 haplotypes were defined in 40 individuals of P.hyalocranius, with haplotype diversity of 0.747±0.041, and the nucleotide diversity of 0.00202±0.00019, showing a type of high haplotype diversity and low nucleotide diversity. The full Cytb gene sequences (1141 bp) were obtained,13 variable sites were detected and 9 haplotypes were defined from 40 individuals of N. taihuensis, with haplotype diversity of 0.609±0.078, and nucleotide diversity of 0.00094±0.00027, which had a type of high haplotype diversity and low nucleotide diversity. The partial COⅠ gene sequences (630 bp) were obtained, 2 variable sites were detected and 3 haplotypes were defined in 40 individuals of N. taihuensis, with haplotype diversity of 0.232±0.085, and nucleotide diversity of 0.00038±0.00014, indicating that it had a type of low haplotype diversity and low nucleotide diversity. The neutrality test revealed that icefish P. hyalocranius and N. taihuensis in Lake Gaoyou had negative Tajima′s D and Fu′s F_s values, with significant difference, and mismatch distribution analysis map showed a peak type, suggesting P. hyalocranius and N. taihuensis have experienced population expansion in the history. The findings indicate that it should take much more measures to protect the icefish resources in Lake Gaoyou.
		2020 Vol. 39 (2): 258-264 [Abstract] ( 162 ) HTML (1 KB) PDF (11869 KB) ( 228 )

	265	Isolation, Identification and Nitrogen Removal Effect of Nitrifying Bacteria in Sediment and Water of Pacific White Shrimp Litopenaeus vannamei Culture Ponds
		ZHANG Dajuan, ZHANG Shulin, DAI Wei, KONG Xin, WANG Zebin, BI Xiangdong
		DOI: 10.16378/j.cnki.1003-1111.2020.02.015
		Five strains of bacteria were isolated and purified from water and sediment in Pacific white leg shrimp Litopenaeus vannamei culture ponds using dilution-plate method and streak plate method, after Gram staining, and identified as Pseudomonas mendocin, Methylobacterium aminovorans, Rhizobium radiobacter, P. stutzeri and Microbacterium oxydans by morphological observation, physiological and biochemical characteristics and 16S rDNA sequence analysis to investigate the component of bacteria of water and sediment in the Pacific white leg shrimp culture pond. The water from the shrimp ponds was filtered into 250 mL conical flasks and inoculated with the five strains (with final density of 2 ×10⁷ cfu/mL) and cultured at 30 ℃ and 120 r/min for 48 hours to study their nitrification function and ammonia nitrogen removal rates.The ammonia nitrogen removal efficiency was shown to be all above 85%, 88.83% in P. mendocin and 91.73% in P. stutzeri; the removal efficiency of nitrite nitrogen were all above 90%, 95.08% in P. mendocin and 97.39% in P. stutzeri; and the removal efficiency of nitrate was above 90%, 90.49% in P. mendocin and 91.22% in P. stutzeri. The findings indicated that Pseudomonas has higher removal efficiency of ammonia nitrogen and nitrite nitrogen, and has potential application in treatment of shrimp effluent.
		2020 Vol. 39 (2): 265-270 [Abstract] ( 219 ) HTML (1 KB) PDF (12357 KB) ( 179 )

	271	Path Analysis of Quantitative Traits of Shellfish Solenaia oleivora Population in Ganjiang River
		ZHANG Genfang, ZHANG Wenfu, FANG Aiping, YANG Shoubao
		DOI: 10.16378/j.cnki.1003-1111.2020.02.016
		Seven quantitative traits including shell length, shell width, shell height, body height, body weight, shell weight and soft part weight were measured in 40 wild shellfish Solenia oleivora collected from Poyang Lake randomly to analyze the correlation between quantitative traits and the main traits influencing soft part weight by correlation analysis, path analysis, multivariate regression analysis, and optimal regression equation. The results showed that the shellfish had 65.62% of dressing rate and very significant phenotypic correlation between various quantitative traits (P<0.01). Body weight, as the main factor, had the greatest direct effect on soft part weight, and the effects of shell length, shell width, shell height, body height and shell weight on soft part weight were mainly indirect through body weight, with the comprehensive determining effect of 96.08%, the most important factor affecting flesh weight and had breeding significance. The optimal regression equation of quantitative traits on soft part weight was expressed as: y=-18.548+0.690x₁-0.442x₂+6.804x₃, through stepwise regression analysis, where y is soft part weight (g), x₁ is body weight (g), x₂ is shell weight (g), and x₃ is body height (cm).
		2020 Vol. 39 (2): 271-276 [Abstract] ( 158 ) HTML (1 KB) PDF (9853 KB) ( 117 )

	277	Analysis of Current Situation and Spatial Layout of National Aquatic Germplasm Reserves in Heilongjiang Province
		CUI Kangcheng, LIU Wei, LI Peilun, GAO Wenyan, WANG Jilong, TANG Fujiang
		DOI: 10.16378/j.cnki.1003-1111.2020.02.017
		The rationality of the spatial layout of the national aquatic germplasm reserves (referred to as the reserves) were evaluated to provide scientific basis for management agencies to make regulations in this study. Based on the list data of the reserves, classification, meta-analysis and spatial overlapping methods were employed to analyze the current situation and then assessed the rationality of its spatial layout. The results showed that by the end of the year 2016, there were 25 reserves in the Heilongjiang Province with an area of 1428.8 km², where 41 species of fish distributed in these 25 reserves, which are protecting endangered fishes with high economic value and genetic value. From 2011 to 2016, the newly established reserves were mainly distributed in the central and southern area in Heilongjiang Province, which meant the distribution of reserves became more rational. Although the layout of fish habitat types tended to be rational, the structural imbalance was serious. Based on natural zoning, the habitat types and main species showed good complementarity between each eco-geographic area and vegetation zone. However, the proportion of protected areas varied greatly in each zone (belt), and the spatial layout needed to be optimized. According to these results, several suggestions are discussed.
		2020 Vol. 39 (2): 277-285 [Abstract] ( 174 ) HTML (1 KB) PDF (16983 KB) ( 138 )

Overview and Specific Topic

	286	Pond Culture of Edible Jellyfish Rhopilema esculentum in North China Coast: Research Progress
		LI Yunfeng, LI Yulong, ZHOU Zunchun, TIAN Meilin, BAO Xiangbo, HE Chongbo
		DOI: 10.16378/j.cnki.1003-1111.2020.02.018

		2020 Vol. 39 (2): 286-291 [Abstract] ( 372 ) HTML (1 KB) PDF (10329 KB) ( 196 )

	292	Sources and Applications of Poly-β-hydroxybutyrate in Aquaculture
		YANG Jing, BAI Lu, MA Hongli, WANG Yiting, GUO Sicong, YE Shigen
		DOI: 10.16378/j.cnki.1003-1111.2020.02.019

		2020 Vol. 39 (2): 292-298 [Abstract] ( 243 ) HTML (1 KB) PDF (11384 KB) ( 164 )