• Volume 40,Issue 12,2016 Table of Contents
    Select All
    Display Type: |
    • >目录
    • CONTENTS

      2016, 40(12):0-0. DOI: 10.11964/jfc.20161200

      Abstract (1659) HTML (0) PDF 250.13 K (1370) Comment (0) Favorites

      Abstract:

    • >PAPERS
    • Molecular cloning, expression pattern and prokaryotic expression of anti-Müllerian hormone (amh) gene in Osteoglossum bicirrostum

      2016, 40(12):1801-1812. DOI: 10.11964/jfc.20160410355

      Abstract (1800) HTML (758) PDF 2.69 M (1715) Comment (0) Favorites

      Abstract:In order to explore the function and expression pattern of anti-Müllerian hormone (amh) gene in Osteoglossum bicirrostum, this study cloned the whole cDNA of amh gene in O. bicirrostum using RACE method, and found that O. bicirrostum had two different hypotypes——amh1 and amh 2(Genbank no.:KU378662, KU378663) of this gene. The result of sequence analysis showed that Amh1 had the full-length of 2277 bp, and encoded 623 amino acids; Amh2 had the full-length of 2181 bp, and encoded 355 amino acids. The homology analysis showed that the Amh in O. bicirrostum shared little conservation, and the similarity compared with its coordinal Scleropages formosus was the highest (85.64%), but that with fishes in other families was lower than 42%. Phylogenetic analysis showed that Amh came to be a cluster with Osteoglossiformes Amh and was closely related with lower teleost species such as Clupeiformes and Cypriniformes, which agreed with the evolutionary position of O. bicirrostum. The real-time fluorescent quantitative PCR results showed that amh was expressed generally in many tissues. The expression of amh1 was the highest in the testis, and much higher than that in ovary and other tissues. The expression of amh2 was also the highest in the testis, and much higher than that in other tissues, but much lower than the expression of amh1 in the testis. We constructed prokaryotic expression vectors pColdⅠ-amh1 and pColdⅠ-amh2, and successfully induced proteins of 68 and 48 ku in Escherichia coli, which laid the foundation for further study of amh in O. bicirrostum.

    • Indirect enzyme-linked immunosorbent assay (ELISA) for rapid detection of Streptococcus agalactiae isolated from tilapia

      2016, 40(12):1906-1914. DOI: 10.11964/jfc.20160110254

      Abstract (1655) HTML (442) PDF 1.19 M (1632) Comment (0) Favorites

      Abstract:A bacterium LB110808-2 was isolated from the spleen of a moribund tilapia in August 2011 in Guangxi Province, and identified as Streptococcus agalactiae by 16 S rRNA gene. The antisera against strain LB110808-2 were obtained from the New Zealand white rabbit. The titer of the polyclonal antibody was 1:2560. This polyclonal antibody was used as primary antibody in indirect enzyme-linked immunosorbent assay (ELISA). The goat anti-rabbit IgG-HRP was used as secondary antibody. The indirect ELISA method of rapid detection of S. agalactiae was developed. The basic procedure of the indirect ELISA was as follows:S. agalactiae antigen was diluted with 0.05 mol/L Carbonate buffer (pH 9.6) and 100 μL diluted antigen was added to each well of the 96 well plate, followed by drying out at 60℃. The plate was washed three times with 300 μL of PBST (PBS+0.2% Tween 20) buffer, and 300 μL of 1% BSA blocking buffer (1% Albumin from bovine serum in PBST) was added to each well and the plate was incubated at 37℃ for l h. Subsequently, the plate was washed three times with PBST buffer, and each well was added with diluted positive serum or negative serum before incubating the plate at 37℃ for l h. Each well of the plate was added with goat anti-rabbit IgG-HRP after the plate was washed with PBST buffer three times. The plate was then incubated at 37℃ for l h, and was washed three times with PBST buffer. Each well was added 100 μL single-component TMB soluble substrate solution. The plate was then incubated at 37℃ for 20 min in dark place. The reaction was terminated with 50 μL 2 mol/L H2SO4. The value of OD450 was determined by the ELISA reader.
      The optimum coated concentration of the antigen was determined to be 106 CFU/mL using chessboard titration method. The optimum antiserum concentrations of the primary antibody and the enzyme linked secondary antibody were determined to be 1:10 000 and l:1000, respectively. The sensitivity of the serum was tested, and the sensitivity of S. agalactiae that can be detected was 103 CFU. Cross reactions of the antiserum with the strains of other common aquatic pathogenic bacteria were detected, and all the results were negative. Inhibition rate was 72.02% in inhibition test. The cross assay and the inhibition assay indicated that this method had high specificity. The method was optimized and standardized to detect the infected S. agalactiae isolated from the diseased tilapia from 2007 to 2013. All the 44 bacterial strains tested were positive, with a 100% positive detection rate. Next, we conducted the test of artificial infection using the S. agalactiae. Seventy percent of the fish were dead. Among the dead fish, 30 samples were detected from the brain tissue, and the positive detection rate was 100%. Among the live fish, 20 samples were detected from the brain, liver and spleen. None was positive from the brain tissue, but the liver and spleen were detected as positive, accounting for 25% and 50%, respectively. These results indicated that this assay can be used to detect not only the dead fish, but also the carrier. Thus, the established indirect ELISA method is very important for rapid and accurate diagnosis of tilapia infected by S. agalactiae at the early stage.

    • Expression analysis of two I-type lysozyme genes from Ruditapes philippinarum under temperature and salinity stress and Vibrio anguillarum challenge

      2016, 40(12):1813-1822. DOI: 10.11964/jfc.20160110249

      Abstract (1911) HTML (504) PDF 2.33 M (1611) Comment (0) Favorites

      Abstract:I-type lysozymes have been found to play significant roles in the innate immune responses of mollusk. In the present study, the full-length cDNA of an I-type lysozyme (designated RpiLYZ-2) was cloned from Ruditapes philippinarum by RACE approaches. The open reading frame of RpiLYZ-2 was 471 bp and encoded a polypeptide of 156 amino acids. The RpiLYZ-2 transcript was expressed in all detected tissues with the highest expression level in mantle and the lowest expression level in muscle. After being exposed to temperature[(29±1), (21±1), (13±1)℃, salinity (32, 22 and 12) stress and Vibrio anguillarum challenge, the expression of RpiLYZ-1 and RpiLYZ-2 displayed distinct pattern in the detected tissues. After being stimulated by elevated temperature (21℃) or salinity 22 stress, the expression pattern of RpiLYZ-1 transcript was decreased after the initial increase, while the expression pattern of RpiLYZ-2 transcript displayed an opposite trend. After being stimulated by elevated temperature 29℃ or salinity 12 stress, the expression pattern of RpiLYZ-1 transcript was down-regulated as time progressed on, while the expression of RpiLYZ-2 mRNA showed an opposite trend. After being challenged with V. anguillarum, a significant up-regulation of RpiLYZ-1 was observed except 12 h, while the expression of RpiLYZ-2 mRNA was significantly inhibited at the early stage of bacterial challenge and recovered at 72 h. The above results suggested that environmental factors and pathogenic stimulation affected the clam's innate immune responses and the expression of RpiLYZ-1 and RpiLYZ-2, and functional division perhaps existed between RpiLYZ-1 and RpiLYZ-2.

    • The expression analysis of immune genes and microscopic morphology of CCF cells in response to Cyprinid herpesvirus 2 infection

      2016, 40(12):1915-1922. DOI: 10.11964/jfc.20160110240

      Abstract (1849) HTML (578) PDF 2.04 M (1691) Comment (0) Favorites

      Abstract:The aims of the current study were to investigate the primary culture of dorsal fin from Prussian carp, Carassius auratus gibelio and its susceptibility to Cyprinid herpesvirus 2 due to the lack of commercial cell line supporting CyHV-2 infection. The cells detached from the tissues in 10 days and fully covered the bottom of 25 cm2 culture bottle in 3 weeks. Cyprinid herpesvirus 2 (CyHV-2) continuously propagated in the cultured cells, as confirmed by a quantitive real time PCR, with the highest viral concentration of 106 copies/mL at 3 days post infection. In addition, cell death was observed in the dorsal fin cells upon CyHV-2 infection. Cytopathic effects (CPE) were observed as early as 6 days post-inoculation, and as the infection progressed, CPE became more apparent with cell debris and cellular exudates in inoculated cultures. The expression levels of 8 immune important genes including IL-11, ITLN, PNP5a, MPO, KRT-8, DUSP-1, MHCⅠ and LYZ-C were significantly different after viral challenge, which were determined to be involved in host response to CyHV-2 infection previously. The results above should be helpful in further studies on CyHV-2, including elucidation of pathogenesis, host-pathogen interaction and development of anti-viral drugs that can ultimately lead to prevention of this viral disease.

    • Phylogenetic relationship and taxonomic status of eight Brachionus species (Rotifera) inferred from ND4 and ND5 genes

      2016, 40(12):1823-1829. DOI: 10.11964/jfc.20160110245

      Abstract (1700) HTML (485) PDF 3.69 M (1742) Comment (0) Favorites

      Abstract:Partial portions of ND4 and ND5 genes from Brachionus caudatus, B. diversicornis, B. forficula, B. quadridentatus, B. rubens, B. falcatus, B. leydigi, B. patulus were amplified and sequenced. Combined with ND4 and ND5 genes of B. plicatilis, B. calyciflorus, Rotaria rotatoria and Philodina citrina from GenBank, phylogenetic trees of neighbor-joining (NJ), minimum-evolution (ME) and unweighted pair-group method using an arithmetic average (UPGMA) methods were built with MEGA6.0 software to reveal their phylogenetic relationships and resolve some taxonomy problems. The results showed that the average percentage of divergence for ND4 and ND5 genes sequences in 12 samples was 40.3%. ND4 and ND5 genes were suitable for researching the phylogenesis and evolution of rotifera species in the genus. The relationships of Brachionus showing from the phylogenetic trees were basically consistent with morphological studies. All the three trees showed that B. patulus and B. diversicornis were confirmed to belong to the genus Brachionus.

    • Preparation and preliminary application of a monoclonal antibody against MCP COE protein of Andrias davidianus iridovirus

      2016, 40(12):1923-1930. DOI: 10.11964/jfc.20160110243

      Abstract (1690) HTML (522) PDF 2.64 M (1334) Comment (0) Favorites

      Abstract:This work was to prepare and characterize a monoclonal antibody against MCP COE protein of Chinese giant salamander (Andrias davidianus) iridovirus (CGSIV), so as to provide a valuable tool for CGSIV diagnosis and further researches on CGSIV pathogenesis. After being purified by nitrilotriacetic acid (Ni-NTA) agarose resin, the recombinant MCP COE of CGSIV was used to immunize the BALB/c mice. Three days after the last immunization, spleen cells were removed and fused with myeloma cells. One hybridoma cell strain against the recombinant protein of MCP COE was obtained by screening with the indirect ELISA and limiting dilution assays, which was named 1M6. The McAb of 1M6 was identified to be IgG2b isotype with κ light chain and showed specific reactivity with CGSIV and the recombinant protein of MCP COE. The McAb was largely produced in mouse ascites and then depurated with saturated ammonium sulfate. Indirect ELISA assay showed that the valences of the McAbs in the cells culture supertanant and in mouse ascites were 1:1600 and 1:2×106 respectively. Affinity constant of the McAb of 1M6 was 2×105. By immunofluorescence assay, the presence of CGSIV was observed in not only the cytoplasm but also the nucleus of CGSIV infected EPC cells. In conclusion, the prepared McAb has high titer and good specificity, which will lay the foundation for further studies on the control of CGSIV.

    • Effect on antioxidant defense in hepatopancreas of Carassius auratus after poly I:C injection under hypoxia

      2016, 40(12):1830-1841. DOI: 10.11964/jfc.20160110241

      Abstract (1988) HTML (509) PDF 2.78 M (1543) Comment (0) Favorites

      Abstract:A natural triploid Qihe crucian carp, Carassius auratus, is an important commercial fish, with the twice thickness of common crucian carp in the back. Hypoxia always produces the important effects on fish physiological and biochemical function and immune protection, and assessing the effect of poly I:C stimulation on antioxidant defense in fish under hypoxia is helpful to understand the oxidative stress and immune ability, as well as the susceptibility to pathogen in fish under hypoxia. The experimental fish, with the body weight of (23±2) g, and the body length of (11±1) cm were cultivated at different dissolved oxygen levels (6, 4, 2 and 1 mg/L) respectively for 7 days. Then, each fish was injected 2 mg/mL poly I:C 100 μL in the treated group and was injected 0.75% NaCl 100μL in the control group. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and the mRNA relative expression of Cu/Zn-SOD, Mn-SOD, CAT and GPx, as well as the content of malondialdehyde (MDA), were measured after injection at 0, 12, 24, 48, 96 and 168 h. The activities of antioxidant enzymes and the levels of mRNA expression in hepatopancreas of fish, under hypoxia for 7 days, were more significantly increased at DO 4 mg/L than at the normal DO 6 mg/L. It implies that fish can reduce the adverse effects at low oxygen level to a certain degree. The activities and the mRNA relative expression of SOD, CAT, GPx in hepatopancreas were more significantly decreased at DO 1 and 2 mg/L than at 6 mg/L. It was suggested that the capacities of antioxidant defense decreased under hypoxia and showed that oxidative stress occurred when the generation rate of ROS exceeded the removal rate, and lead to the accumulation of MDA, a lipid peroxidation product, in hepatopancreas. Therefore, the content of MDA increased with the decreasing of dissolved oxygen concentration. After poly I:C stimulation in hypoxia, antioxidant enzyme activities and mRNA relative expression levels were significantly reduced, compared to the corresponding control, at 48, 96 and 168 h. It is indicated that antioxidant defense ability was reduced in hepatopancreas of C. auratus after poly I:C infection in hypoxia and then caused serious oxidative stress. MDA content was significantly higher in the treated group than that in the control group. It was implied that oxidative stress was intensified in hepatopancreas of C. auratus after poly I:C injection in hypoxia. In this study, it is demonstrated that the antioxidant defense ability decreased under hypoxia and caused oxidative stress. Pathogenic analogues poly I:C stimulation under hypoxia condition could further weaken antioxidant defense ability and aggravate the degree of oxygen stress. In the cultivation of C. auratus, when DO decreased to less than 4 mg/L, dissolve oxygen should be supplemented and increased to maintain the normal level of antioxidant defense in fish.

    • Analysis of volatile components in various cured hairtail by electronic nose and HS-SPME-GC-MS

      2016, 40(12):1931-1940. DOI: 10.11964/jfc.20160410346

      Abstract (1776) HTML (638) PDF 1.95 M (1935) Comment (0) Favorites

      Abstract:The impacts of various processing techniques on volatile compounds of cured hairtail were studied using an electronic nose and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The obtained results indicated that the contributions of the first and second principal components were 96.44% and 2.60%, respectively, which contained sufficient sensory information to different samples. Totally 27, 45 and 56 volatile compounds were detected from hairtail samples that were fresh, traditional cured and fermented cured, respectively, and most of volatile compounds were aldehydes, alcohols and ketones. Hexanal, benzaldehyde, octanal, (E, E)-2, 4-heptadienal, 1-octen-3-ol, hexanol, 3-methyl-1-butanol, 3-hydroxy-2-butanone and trimethylamine were found involved in the formation of characteristic flavor of hairtail. Fresh hairtail exhibited mainly fishy and fruity flavors, and traditional cured hairtail showed fatty, mushroom-muddy and fruity flavors, while the main flavor of fermented cured hairtail were buttery, grassy-fatty and fruity, and these flavors were more intense and better-distributed.

    • Transcriptomic profiling of Pyropia haitanensis blade in responding to low-salinity stress

      2016, 40(12):1842-1849. DOI: 10.11964/jfc.20160410374

      Abstract (2247) HTML (553) PDF 2.09 M (1660) Comment (0) Favorites

      Abstract:In order to probe the physiological mechanisms of Pyropia haitanensis blade responding to low-salinity stress, in this paper, the next-generation high-throughput sequencing technology was applied to compare transcriptome data of P. haitanensis blades being cultured at normal salinity of 26 (control group) and at low-salinity of 3 (stress group) for 3, 6, and 9 hours, respectively. Results revealed that the de novo assembly of sequence data generated 33 872 unigenes, of which average length was 612 base pairs. Compared with control group, 1 108, 1 638 and 1 881 differentially expressed genes were produced from three stress groups, respectively. The analysis of gene ontology functional enrichment revealed that some important biological processes related to low-salinity stress, such as single-organism metabolic process, monosaccharide biosynthetic process, monosaccharide catabolic process, gluconeogenesis, organic substance catabolic process, etc., got significantly enriched. The results of KEGG pathways enrichment showed that metabolic pathway varied mostly with different treated time. Differentially expressed genes produced from LS 3 h vs LS 0 h group tended to cluster into three KEGG metabolic pathways, one of which related to photosynthesis, and the other two were both interrelated with amino acid biosynthesis. However, under low-salinity stress for 6 and 9 hours, most differentially expressed genes were enriched in metabolic pathways carbohydrate involved. Quantitative real-time PCR validation results showed that expression levels of eight selected differentially expressed genes were consistent with high-throughput sequencing results. All the results above revealed that stress responses of P. haitanensis were time-specific when exposed to low-salinity. In the early stage, P. haitanensis mainly synthesizsed or degraded protein to resist low-salinity environment. With low-salinity stress carried on, cells changed the content of soluble substances and slowed down energy metabolism to resist low-salinity adversity.

    • Analysis of genetic diversity and genetic bottleneck in Oreochromis niloticus populations under domestication and selective breeding

      2016, 40(12):1850-1865. DOI: 10.11964/jfc.20160110219

      Abstract (1906) HTML (508) PDF 1.63 M (1929) Comment (0) Favorites

      Abstract:Domestication and selective breeding become one of the main driving force of adaptive evolution for domestic animals. The introduced populations of Nile tilapia(Oreochromis niloticus) in China mainland have experienced a long-term domestication and selective breeding, which provide a unique opportunity to study adaptive evolution of fish species under domestication and selective breeding. In this study, we screened 12 polymorphic microsatellite loci in nine independent-reared strains (four of which were used for selective breeding and five for ranching) and their wild progenitor population of Nile tilapia to assess genetic diversity and genetic bottleneck across native, domesticated and selective breeding populations. The parameters of genetic variability in native, domesticated and selective breeding populations were summarized as follows:the average number of effective alleles (AE) was 5.433, 5.113-6.515, 3.239-6.734; the value of average expected heterozygosity (HE) was 0.812, 0.796-0.859, 0.657-0.858; the value of average polymorphism information content (PIC) was 0.768, 0.753-0.819, 0.601-0.818; the value of average Wright's inbreeding coefficient (FIS) was 0.323, 0.166-0.342, 0.249-0.314. LSD-t test showed that no significant differences were detected between native population and populations under artificial selection(domesticated and selective breeding populations) in terms of AE and HE. The HE values in three domesticated populations (EGY,WY and GD) were significantly higher than that in one selective breeding population(XJF).Analysis of bottleneck revealed that all populations have experienced a historical population bottleneck. Moreover, recent genetic population bottleneck was detected in native population, two domesticated populations (WY and EGY) and two selective breeding populations (JNM and XJF). The size of other historically bottlenecked populations may have been restored through new mutations and gene flow. The effective population sizes (NE) of native, domesticated and selective breeding populations were 177, 29-117 (an average of 57.4), 84-123 (an average of 102.8), respectively. The results of this study provided valuable information not only for the sustainable use of domesticated populations, but also for further genetic improvement of selective breeding populations of Nile tilapia. More importantly, the findings of this study provided a new reference basis for population structure and population dynamics of fish species under domestication and selective breeding.

    • Study on predatory effect of Ischnura heterosticta larvae on Misgurnus anguillicaudatus larvae

      2016, 40(12):1866-1873. DOI: 10.11964/jfc.20151210211

      Abstract (1874) HTML (697) PDF 1.74 M (1921) Comment (0) Favorites

      Abstract:To investigate the influence of the predator, Ischnura heterosticta larvae on survival rate of Misgurnus anguillicaudatus larvae, we studied the predatory effect of I. heterosticta larvae on M. anguillicaudatus larva based on the predator-prey relationship theory. Results of experiments showed that:the predation functional response of I. heterosticta larvae to M. anguillicaudatus larvae belonged to type Holling-Ⅱ. With the increase in daily age of M. anguillicaudatus larvae, the moment attack (a') and the largest preying amount per day (1/Th) declined. The preying amount increased as prey density increased. The predatory function of different sizes of I. heterosticta larva to M. anguillicaudatus larva had significant differences. For I. heterosticta larvae with different body lengths (16.3±0.2), (13.1±0.3), (9.8±0.2) and (5.8±0.3) mm to 3-day-age larvae of M. anguillicaudatus, the moment attack and the largest preying amount per day were 0.8349, 0.5724, 0.2002, 0.0432, and 27.39, 18.99, 9.49, 3.14, respectively. With the density of I. heterosticta larvae increased, the mutual interference between the individuals led to reduction in the time of a single I. heterosticta larva looking for prey. Under intraspecific competition, predatory effect rate (E) as a function of density (P) was E=0.1403×P-0.2361. With the increase of M. anguillicaudatus larvae and I. heterosticta larvae density, interference effect increases obviously, predatory efficiency rate (E) drops, but had little impact on preying amount, and the model of interspecific interference was Na=(0.7841×P-0.1560×N)/(1+0.0305×N). The results demonstrated that I. heterosticta larva is important predator, which can remarkably reduce the survival rate of M. anguillicaudatus larvae.

    • Effects of stocking density on growth, sexual differentiation and gonad development of Macrobrachium rosenbergii

      2016, 40(12):1874-1882. DOI: 10.11964/jfc.20140609340

      Abstract (1867) HTML (518) PDF 1.74 M (1815) Comment (0) Favorites

      Abstract:The effects of stocking density on growth, sex differentiation and early gonadal development of M. rosenbergii were analyzed by the indexes (such as growth, survive, sex differentiation and gonadal development) at four stocking densities (7.50×104, 12.75×104, 42.00×104 and 97.50×104 ind/hm2). The result showed that:at the stocking densities from 7.50×104 to 97.50×104 ind/hm2, the growth, specification uniformity, sex differentiation and gonadal development of M. rosenbergii were significantly influenced by stocking density. With the time prolonged, the greater growth inhibitory effects from stocking density appeared. The ratio of body weight gain acceleration of M. rosenbergii in groups of 7.50×104 ind/hm2 to 97.50×104 ind/hm2 increased from 2.3 at 10 d to 3.4 at 80 d; the sex differentiation and gonadal development time of low stocking density groups is about 10d earlier than that of the high stocking density group, but the sex differentiation and gonadal development specification of low stocking densities is greater than that of the high stocking densities. The initial average body length of female M. rosenbergii in group of 7.50×104 ind/hm2 (4.158±0.592) cm is 1.09 cm longer than that in group of 97.50×104 ind/hm2; sex ratio was not influenced by stocking density, but the survival rate of female M.rosenbergii was significantly influenced. The external morphology scale and age were delayed by the influence of stocking density. The result showed that the growth and gonadal development were significantly influenced by stocking densities. Suitable stocking density is an effective measure to prevent the precocity of M. rosenbergii. These results may provide a basis for the breeding production and genetic breeding of M. rosenbergii.

    • Evaluation of phenotypic traits of two strains of the Kumamoto oyster (Crassostrea sikamea)

      2016, 40(12):1883-1888. DOI: 10.11964/jfc.20151110150

      Abstract (1821) HTML (516) PDF 1.59 M (1794) Comment (0) Favorites

      Abstract:The phenotypic traits of two strains the Kumamoto oyster Crassostrea sikamea were evaluated by the reproductive biology method according to the number of radiation ribs from left shell with the Zhangjiang population as base stocks in May 2013. Results showed that the fresh weight, shell weight and fecundity of mulit-radial ridge parents were significantly greater than those of non-radial ridge, while no significant difference in the egg diameter, fertilization rate, hatching rate, D larval size and metamorphic size was found between two strains. However, the survival ability and growth potential of multi-radial ridge strain were both better than those of non-radial ridge strain. Growth traits of two strains were affected by the culture conditions, while hardly any effect was observed on the viability of the environment during grow-out stage at two different sites. The radial ridge of the left shell of oyster is dominant and it is mainly controlled by a dominant gene, while the multi-ridge trait is recessive trait, which can be stably inherited. This study provided a solid theoretical foundation and practical experience for the cultivation of the multi-ridge culture and the genetic mechanism of the left shell of the oyster.

    • Estimates of genetic parameters for golden shell color and correlation with growth traits in the golden shell strain of Pacific oyster (Crassostrea gigas)

      2016, 40(12):1889-1896. DOI: 10.11964/jfc.20160110269

      Abstract (2063) HTML (513) PDF 2.84 M (1596) Comment (0) Favorites

      Abstract:The Pacific oyster (Crassostrea gigas) accounts for the largest production of all bivalve species in the world, and shows a wide range of between- and within-individual variation of shell colour trait. However, little is known about the genetic parameters of its shell color trait. Four generations of family selection and mass selection were carried out to develop the excellent strains of C. gigas with golden shell colour and rapid growth traits. A total of 25 full-sib families from 10 male and 30 female parents were established successfully by using the method of nested design in 2014. These parental breeders were collected from the fourth-generation selective strain of C. gigas produced in 2013.At the age of 9 months, we measured and compared the phenotypic growth traits and the shell colour parameters based on the CIE 1976 Lab colorimetric system among progeny. The genetic parameters of shell color pigmentation and correlation with growth traits were estimated using ASReml 3.0. The results showed that the average values of the colour parameters of the L*(lightness), a*(redness), and b*(yellowness) were greater than those of the control group except ΔE (colour difference), especially b* which represented the difference between the golden breeding strain and the common population, evidencing the expected selection effect of the golden shell color trait.Coefficients of variation of the progeny were 13.14%~31.84% for growth traits, and 12.34%-63.89% for color parameters, suggesting that there was great genetic variation. Heritabilities of L*, a*, b* and ΔE were 0.13±0.09, 0.69±0.19, 0.30±0.13, 0.38±0.15, respectively. The phenotypic correlations and genetic correlations of L*, a*, b* and ΔE had significant differences, with the ranges of -0.19~0.80 and -0.25-0.37 respectively. The phenotypic correlations and genetic correlations between the growth traits and color parameters were very low, ranging from -0.10 to 0.13 and -0.04 to 0.26 respectively. The results demonstrated that the heritability of the golden-colour shell trait of C. gigas was significantly moderate and high except L*, suggesting the potential for the selection of the golden shell color trait was high. However, indirect selection of the shell color trait using growth traits is infeasible due to their low correlations. Furthermore, only the color traits and growth traits were selected as the targets of selective breeding at the same time, and the traits could be improved. The present study provides important information for future selective breeding programmes for C. gigas with golden shell color trait.

    • Effects of social hierarchy on the growth, survival and related enzyme activities of Sepia pharaonis

      2016, 40(12):1897-1905. DOI: 10.11964/jfc.20160110247

      Abstract (1710) HTML (494) PDF 1.49 M (1746) Comment (0) Favorites

      Abstract:To explore whether big individuals can affect small individuals' growth for cuttlefish Sepia pharaonis under the stress of social hierarchy, this study was conducted indoors in small cages (Φ=60 cm, h=20 cm), and the survival rate, specific growth rate, oxygen consumption rate, ammonia excretion rate and metabolic enzyme (ATP enzyme, pyruvate kinase and hexokinase) changes were measured after 40 days of cultivation, to analyze the effects of different body sizes (large size L:body weight of 4 to 5 g, middle size M:body weight of 2.5 to 3.5 g, small size S:body weight of 1 to 2 g, with separate cultivation and mixed cultivation (LMS ratio 1:1:1), using single factor design. The results showed that:the L S. pharaonis' special growth rate was not significantly different between separate cultivation and mixed cultivation, but the growth rates of groups M and S S. pharaonis' were significantly lower with separate cultivation, specific growth rates for each group were LMS-M (3.12±0.35)%/d, M (5.21±0.24)%/d, LMS-S(1.39±0.28)%/d and S (4.37±0.42)%/d; after 10 days of cultivation, the survival rates of S. pharaonis were not significantly different between separate cultivation or mixed cultivation, but after 20 days of cultivation, the survival rate of mixing cultivation was significantly lower than that of separate cultivation; after 40 days, the survival rate for each group were LMS(41%±5.35%), M(60%±4.58%), L(61%±6.43%) and S (63%±5.57%). The oxygen consumption rate showed no significant difference for separate cultivation and mixed cultivation, but groups M and S with mixing cultivation oxygen consumption rate was lower than the single standard breeding groups M and S S. pharaonis' oxygen consumption rate, oxygen consumption rate in each group were LMS-M[(0.48±0.03) mg/(g·h)], M[(0.69±0.02) mg/(g·h)], LMS-S[(0.75±0.04) mg/(g·h)], S[(0.94±0.04) mg/(g·h)]; L S. pharaonis' ammonia excretion rate showed no significant difference under seperate cultivation and mixed cultivation, but the ammonia excretion rates of mixed cultivation of groups M and S were lower than the single standard breeding groups M and S S. pharaonis' oxygen consumption rates, ammonia excretion rates in each group were LMS-M[(0.057±0.004) mg/(g·h)], M[(0.082±0.007) mg/(g·h)], LMS-S[(0.085±0.007) mg/(g·h)], S[(0.135±0.007) mg/(g·h)]; L S. pharaonis' ATP enzyme, pyruvate enzyme and hexokinase activities showed no significant difference between separate cultivation and mixed cultivation, but mixing cultivation of groups M and S, S. pharaonis' ATP enzyme, pyruvate kinase and hexokinase activity were lower than the single standard breeding group M and S S. pharaonis' oxygen consumption rate, ATP enzyme activity in each group were LMS-M[(1.25±0.16)U/mg prot], M[(2.74±0.26) U/mg prot], LMS-S[(0.77±0.11) U/mg prot], S[(1.94±0.09) U/mg prot]; pyruvate kinase activity in each group were HET-M[(51.14±6.24) U/mg prot], M[(78.05±8.38) U/mg prot], LMS-S[(27.94±6.65) U/mg prot], S[(55.92±2.81) U/mg prot]; hexokinase activity in each group were LMS-M[(10.71±1.24) U/mg prot], M[(23.59±1.67) U/mg prot], LMS-S[(5.91±0.83) U/mg prot], S[(13.82±1.66) U/mg prot]. Thus, L S. pharaonis have a significant impact on the normal growth rates of M and S S. pharaonis under mixed cultivation, which is bad for cuttlefish farming.

Current Issue


Volume , No.

Table of Contents

Archive

Volume

Issue

Most Read

Most Cited

Most Downloaded