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Sample records for flounder paralichthys olivaceus

  1. Genetic Linkage Map of Olive Flounder, Paralichthys olivaceus

    PubMed Central

    Kang, Jung-Ha; Kim, Woo-Jin; Lee, Woo-Jai

    2008-01-01

    Olive flounder, Paralichthys olivaceus, is an important fish species in Asia, both for fisheries and aquaculture. As the first step for better understanding the genomic structure and functional analysis, we constructed a genetic linkage map for olive flounder based on 180 microsatellites and 31 expressed sequence tag (EST)-derived markers. Twenty-four linkage groups were identified, consistent with the 24 chromosomes of this species. The total map distance was 1,001.3 cM based on Kosambi sex-average mapping, and the average inter-locus distance was 4.7 cM. Linkage between the loci was identified by an LOD score of ≥3. This linkage map may be used to map quantitative trait loci associated with important traits of the species and may assist in breeding programs. PMID:18497873

  2. Transcriptional Responses of Olive Flounder (Paralichthys olivaceus) to Low Temperature

    PubMed Central

    Hu, Jinwei; You, Feng; Wang, Qian; Weng, Shenda; Liu, Hui; Wang, Lijuan; Zhang, Pei-Jun; Tan, Xungang

    2014-01-01

    The olive flounder (Paralichthys olivaceus) is an economically important flatfish in marine aquaculture with a broad thermal tolerance ranging from 14 to 23°C. Cold-tolerant flounder that can survive during the winter season at a temperature of less than 14°C might facilitate the understanding of the mechanisms underlying the response to cold stress. In this study, the transcriptional response of flounder to cold stress (0.7±0.05°C) was characterized using RNA sequencing. Transcriptome sequencing was performed using the Illumina MiSeq platform for the cold-tolerant (CT) group, which survived under the cold stress; the cold-sensitive (CS) group, which could barely survive at the low temperature; and control group, which was not subjected to cold treatment. In all, 29,021 unigenes were generated. Compared with the unigene expression profile of the control group, 410 unigenes were up-regulated and 255 unigenes were down-regulated in the CT group, whereas 593 unigenes were up-regulated and 289 unigenes were down-regulated in the CS group. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that signal transduction, lipid metabolism, digestive system, and signaling molecules and interaction were the most highly enriched pathways for the genes that were differentially expressed under cold stress. All these pathways could be assigned to the following four biological functions for flounder that can survive under cold stress: signal response to cold stress, cell repair/regeneration, energy production, and cell membrane construction and fluidity. PMID:25279944

  3. Metabolite and gene expression responses in juvenile flounder Paralichthys olivaceus exposed to reduced salinities.

    PubMed

    Wu, Huifeng; Liu, Jialin; Lu, Zhen; Xu, Lanlan; Ji, Chenglong; Wang, Qing; Zhao, Jianmin

    2017-04-01

    Seawater salinity is one of the most important changeable environmental factors influencing the behavior, survival, growth and production of marine organisms. In this work, metabolite and gene expression profiles were used to elucidate the biological effects of reduced salinities in juvenile flounder Paralichthys olivaceus. Metabolic profiling indicated that both reduced salinities (23.3‰ and 15.6‰) enhanced proteolysis and disturbed osmotic regulation and energy metabolism in juvenile flounder P. olivaceus. Furthermore, the low salinity (15.6‰) enhanced anaerobic metabolism indicated by the elevated lactate in flounder tissue extracts. Gene expression profiles exhibited that reduced salinities could induce immune stress and oxidative stress and disturb energy metabolism in juvenile flounder P. olivaceus. In addition, reduced salinities might promote the growth and gonadal differentiation in juvenile flounder P. olivaceus.

  4. Hybrids between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus: karyotype, allozyme and RAPD analyses

    NASA Astrophysics Data System (ADS)

    You, Feng; Wang, Wei; Xu, Dongdong; Zhu, Xiangping; Ni, Jing; Wu, Zhihao; Xu, Yongli; Wang, Xincheng; Zhang, Peijun

    2009-05-01

    The hybrid between olive flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus was produced by artificial insemination of olive flounder eggs with stone flounder sperm. Sinistral and dextral are two types of hybrid progeny after metamorphosis. Karyotypes of both hybrid flounders are the same as those of the two parental species. Of the 22 loci examined from 12 allozymes, 12 confirmed hybridization of the paternal and maternal loci in hybrids and no difference was found in allozyme patterns of sinistral and dextral hybrid fishes. RAPD patterns of these specimens were also studied with 38 primers selected from 104 tested. Among them, the PCR products of 30 primers showed hybridization of the paternal and maternal bands. Genetic variation between hybrids and their parental stocks was analyzed by RAPD using 10 of the above 38 primers. The average heterozygosity and genetic distance were calculated. The results suggested that the filial generation could inherit a little more genetic materials from paternal fish than that from maternal fish.

  5. Cloning and expression of prion protein encoding gene of flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiwen; Sun, Xiuqin; Zhang, Jinxing; Zan, Jindong

    2008-02-01

    The prion protein (PrP) encoding gene of flounder ( Paralichthys olivaceus) was cloned. It was not interrupted by an intron. This gene has two promoters in its 5' upstream, indicating that its transcription may be intensive, and should have an important function. It was expressed in all 14 tissues tested, demonstrating that it is a house-keeping gene. Its expression in digestion and reproduction systems implies that the possible prions of fish may transfer horizontally.

  6. Expression of let-7 microRNAs that are involved in Japanese flounder (Paralichthys olivaceus) metamorphosis.

    PubMed

    Fu, Yuanshuai; Shi, Zhiyi; Wang, Guyue; Zhang, Junling; Li, Wenjuan; Jia, Liang

    2013-06-01

    The let-7 microRNAs (miRNAs), a class of small noncoding RNAs, are phylogenetically conserved and temporally expressed and control the proper timing of events during development as heterochronic genes in many animals. Japanese flounder (Paralichthys olivaceus) undergoes a metamorphosis from the larval to juvenile form. Here, we identified 21 let-7 miRNA precursors from different genome loci in Japanese flounder. P. olivaceus let-7 miRNAs are widely expressed in adult tissues, highly expressed during metamorphosis, but weakly during embryonic development. Exogenous thyroid hormone (0.1 mg/L), which induces premature metamorphosis, significantly promotes the expression of let-7 miRNAs, while thiourea (30 mg/L), which affects metamorphic arrest, inhibits the expression of let-7 miRNAs in metamorphosis in P. olivaceus. These results show that let-7 miRNAs widely participate in tissue development and metabolism during development and are also involved in regulation of temporal transitions associated with cell proliferation and differentiation during metamorphosis, in P. olivaceus.

  7. Identification of candidate piRNAs in the gonads of Paralichthys olivaceus (Japanese flounder)

    PubMed Central

    WANG, Chun-Lei; WANG, Zhi-Peng; WANG, Jia-Qi; Li, Ming-You; CHEN, Xiao-Wu

    2016-01-01

    Piwi-interacting RNA (piRNA) plays an important role in the gonadal development and maintenance of Teleostei. In this study, piRNA libraries derived from the adult gonads of Japanese flounder (Paralichthys olivaceus) were generated using next-generation sequencing technology. Using zebrafish piRNAs as a reference, 5 865 unique candidate piRNAs were identified; 289 candidate piRNA clusters (PRCs) were generated from the above piRNAs. Among the isolated candidate PRCs, a total of 38 ovary-specific, 45 ovary-bias, 24 testis-specific, and 131 testis-bias PRCs were found. The relative expression levels of seven PRCs were validated through quantitative reverse transcription-polymerase chain reaction. The results of this study will help facilitate exploration of the development and maintenance of the phenotypic sex mechanism in P. olivaceus. PMID:27686790

  8. Vertebral deformities in hatchery-reared and wild-caught juvenile Japanese flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Lü, Hongjian; Zhang, Xiumei; Fu, Mei; Xi, Dan; Su, Shengqi; Yao, Weizhi

    2015-01-01

    The present study compared vertebral deformities of hatchery-reared and wild-caught juvenile Japanese flounder, Paralichthys olivaceus. A total of 362 hatchery-reared flounder (total length 122.5-155.8 mm) were collected from three commercial hatcheries located in Yantai, East China, and 89 wild fish (total length 124.7-161.3 mm) were caught off Yangma Island near Yantai City (37°27'N, 121°36'E). All the fish were dissected, photographed, and images of the axial skeleton were examined for vertebral deformities. Compared with wild-caught flounder in which no deformed vertebrae were detected, 48 (13.3%) hatcheryreared fish had deformed vertebrae. The deformities were classified as compression, compression-ankylosis, and dislocation-ankylosis. The vertebral deformities were mainly localized between post-cranial vertebra 1 and 3, with vertebrae number 1 as the most commonly deformed. The causative factors leading to vertebral deformities in reared Japanese flounder may be related to unfavorable temperature conditions, inflammation, damage, or rupture to the intervertebral ligaments under rearing conditions. Furthermore, no significant difference in the total number of vertebral bodies was observed between wild-caught (38.8±0.4) and hatchery-reared flounder (38.1±0.9) ( P>0.05). However, the number of vertebral bodies of hatchery-reared and wild-caught flounder ranged from 35 to 39 and from 38 to 39, respectively.

  9. Establishment and characterization of a testicular Sertoli cell line from olive flounder Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Peng, Limin; Zheng, Yuan; You, Feng; Wu, Zhihao; Zou, Yuxia; Zhang, Peijun

    2016-09-01

    The culture of Sertoli cells has become an indispensable resource in studying spermatogenesis. A new Sertoli cell line (POSC) that consisted predominantly of fibroblast-like cells was derived from the testis of the olive flounder Paralichthys olivaceus and sub-cultured for 48 passages. Analysis of the mtDNA COI gene partial sequence confirmed that the cell line was from P. olivaceus. Cells were optimally maintained at 25°C in DMEM/F12 medium supplemented with fetal bovine serum, basic fibroblast growth factor, and epidermal growth factor. The growth curve of POSC showed a typical "S" shape. Chromosome analysis revealed that the cell line possessed the normal P. olivaceus diploid karyotype of 2n=48t. POSC expressed dmrt1 but not vasa, which was detected using RT-PCR and sequencing. Immunocytochemistry revealed that the cells exhibited the testicular Sertoli cell marker FasL. Therefore, POSC appeared to consist of testicular Sertoli cells. Bright fluorescent signals were observed after the cells were transfected with pEGFP-N3 plasmid, with the transfection efficiency reaching 10%. This research not only offers an ideal model for further gene expression and regulation studies on P. olivaceus, but also serves as valuable material in studying fish spermatogenesis, Sertoli cell-germ cell interactions, and the mechanism of growth and development of testis.

  10. The toxic mechanism of high lethality of herbicide butachlor in marine flatfish flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Guo, Huarong; Yin, Licheng; Zhang, Shicui; Feng, Wenrong

    2010-09-01

    The toxic mechanism of herbicide butachlor to induce extremely high lethality in marine flatfish flounder, Paralichthys Olivaceus, was analyzed by histopathological examination, antioxidant enzymes activities and ATP content assay. Histopathological examination of gill, liver and kidney of exposed fishes showed that gill was a target organ of butachlor. The butachlor seriously impaired the respiration of gills by a series of lesions such as edema, lifting and detachment of lamellar epithelium, breakdown of pillar cells, and blood congestion. The dysfunction of gill respiration caused suffocation to the exposed flounder with extremely high acute lethality. Antioxidant enzyme activity assay of the in vitro cultured flounder gill (FG) cells exposed to butachlor indicated that butachlor markedly inhibited the antioxidant enzyme activities of Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Furthermore, along with the decline of antioxidant enzyme activities, ATP content in the exposed FG cells decreased, too. This infers that the oxidative stress induced by butachlor can inhibit the production of cellular ATP. Similar decrease of ATP content was also observed in the exposed flounder gill tissues. Taken together, as in FG cells, butachlor possibly induced a short supply of ATP in pillar cells by inhibiting the antioxidant enzyme activities and then affecting the contractibility of the pillar cells, which in turn resulted in the blood congestion and suffocation of exposed flounder.

  11. Production and verification of a 2nd generation clonal group of Japanese flounder, Paralichthys olivaceus

    PubMed Central

    Hou, Jilun; Zhang, Xiaoyan; Wang, Yufen; Sun, Zhaohui; Si, Fei; Jiang, Xiufeng; Liu, Haijin

    2016-01-01

    Clonal fishes are useful tools in biology and aquaculture studies due to their isogenicity. In Japanese flounder (Paralichthys olivaceus), a group of homozygous clones was created by inducing meiogynogenesis in eggs from a mitogynogenetic homozygous diploid. As the clones reached sexual maturity, meiogynogenesis was again induced in order to produce a 2nd generation clonal group of Japanese flounder. After 3 months, there were 611 healthy, surviving individuals. Twenty-four microsatellite markers, that covered all the linkage groups of Japanese flounder, were used to identify the homozygosity of the 2nd generation clones; no heterozygous locus was detected. This indicates that the production of a 2nd generation clonal group of Japanese flounder was successful. Restriction-site DNA associated sequencing at the genomic level also confirmed the homozygosity and clonality of the 2nd generation clonal group. Furthermore, these 2nd generation clones had a small coefficient of variation for body shape indices at 210 days of age and showed a high degree of similarity in body characteristics among individuals. The successful production of 2nd generation clones has laid the foundation for the large-scale production of clonal Japanese flounder. PMID:27767055

  12. A Vibrio anguillarum strain associated with skin ulcer on cultured flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Mo, Zhao-Lan; Tan, Xun-Gang; Xu, Yong-Li; Zhang, Pei-Jun

    2001-12-01

    The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to the species Vibrio anguillarum. Challenge by I.M. (intramuscular injection), bath, and oral administration with M3 showed that it was highly pathogenic for Paralichthys olivacues. The LD50 dose was 5.144×103 CFU/ per fish infection by I.M. injection. Recovered inoculated bacteria from the surviving fish revealed that the asymptomatic carriers could be a latent contagious source. Study of the effect of bacterial culture CFS (cell-free-supernatant) showed that the exotoxins produced by M3 play an important role in its pathogenicity for flounder. The resistance of M3 to 36 out of 41 antibiotics indicated that the bacterial disease outbreak was mainly attributable to the frequent and excessive use of antimicrobial agents; and that vaccination would be an effective precaution against bacterial disease.

  13. Analysis of new microsatellite markers developed from reported sequences of Japanese flounder Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Yu, Haiyang; Jiang, Liming; Chen, Wei; Wang, Xubo; Wang, Zhigang; Zhang, Quanqi

    2010-12-01

    The expressed sequence tags (ESTs) of Japanese flounder, Paralichthys olivaceus, were selected from GenBank to identify simple sequence repeats (SSRs) or microsatellites. A bioinformatic analysis of 11111 ESTs identified 751 SSR-containing ESTs, including 440 dinucleotide, 254 trinucleotide, 53 tetranucleotide, 95 pentanucleotide and 40 hexanucleotide microsatellites respectively. The CA/TG and GA/TC repeats were the most abundant microsatellites. AT-rich types were predominant among trinucleotide and tetranucleotide microsatellites. PCR primers were designed to amplify 10 identified microsatellites loci. The PCR results from eight pairs of primers showed polymorphisms in wild populations. In 30 wild individuals, the mean observed and expected heterozygosities of these 8 polymorphic SSRs were 0.71 and 0.83 respectively and the average PIC value was 0.8. These microsatellite markers should prove to be a useful addition to the microsatellite markers that are now available for this species.

  14. Feeding and growth of juvenile Japanese flounder Paralichthys olivaceus in relation to temperature and food supply

    NASA Astrophysics Data System (ADS)

    Fonds, Mark; Tanaka, Masaru; Van der Veer, Henk W.

    The growth of juvenile Japanese flounder Paralichthys olivaceus (Temming et Schlegel) exposed to various feeding and temperature regimes was studied in the laboratory. The temperature limits for growth were estimated from about 9 to 32°C, and highest growth rate was observed at a temperature of 25°C. For fish of an initial total length of about 3 cm, exposed to temperatures between 10 and 30°C with unlimited food, the daily growth rate in length (dL; mm·d -1) was described as a function of temperature (T,°C) by the equation: dL=0.005 T 2 - 0.0000046 T 4 - 0.35. Fish fed with mussel meat or mysids displayed similar protein conversion efficiencies. The relationship between condition factor of the fish and the proximate body composition of the fish is reported.

  15. In vitro acute cytotoxicity of neonicotinoid insecticide imidacloprid to gill cell line of flounder Paralichthy olivaceus

    NASA Astrophysics Data System (ADS)

    Su, Feng; Zhang, Shicui; Li, Hongyan; Guo, Huarong

    2007-04-01

    In vitro acute cytotoxicity of neonicotinoid insecticide imidacloprid (IMI) to the gill cell line of flounder (FG) that collected in the gill of Paralichthys olivaceus, was examined by 3 widely used endpoint bioassays: NR (neutral red), MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) and TCP (total cell protein). The result shows that the IMI increased at concentrations ≥0.5 μg/ml. The IC50 value of NR. MTT, and TCP was 41.86, 38.46, and 39.08 μg/ml, respectively. The ultrastructural observation revealed that the mitochondria of the cells exposed to 60 μg/ml IMI for 48 h were severely damaged, swollen or disrupted, while their nuclei and rough endoplasmic reticulum (RER) remained normal. This would suggest that the mitochondria are probably the primary target of IMI.

  16. Recombination-activating gene 1 and 2 (RAG1 and RAG2) in flounder (Paralichthys olivaceus).

    PubMed

    Wang, Xianlei; Tan, Xungang; Zhang, Pei-Jun; Zhang, Yuqing; Xu, Peng

    2014-12-01

    During the development of B and T lymphocytes, Ig and TCR variable region genes are assembled from germline V, D, and J gene segments by a site-specific recombination reaction known as V(D)J recombination. The process of somatic V(D)J recombination, mediated by the recombination-activating gene (RAG) products, is the most significant characteristic of adaptive immunity in jawed vertebrates. Flounder (Paralichthys olivaceus) RAG1 and RAG2 were isolated by Genome Walker and RT-PCR, and their expression patterns were analysed by RT-PCR and in situ hybridization on sections. RAG1 spans over 7.0 kb, containing 4 exons and 3 introns, and the full-length ORF is 3207 bp, encoding a peptide of 1068 amino acids. The first exon lies in the 5'-UTR, which is an alternative exon. RAG2 full-length ORF is 1062 bp, encodes a peptide of 533 amino acids, and lacks introns in the coding region. In 6-month old flounders, the expression of RAG1 and RAG2 was essentially restricted to the pronephros (head kidney) and mesonephros (truck kidney). Additionally, both of them were mainly expressed in the thymus. These results revealed that the thymus and kidney most likely serve as the primary lymphoid tissues in the flounder.

  17. Effects of ocean acidification on the larval growth of olive flounder (Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Kim, K.-S.; Shim, J. H.; Kim, S.

    2013-04-01

    Little is known about how marine fishes respond to the reduced pH condition caused by the increased CO2 in the atmosphere. We investigated the effects of CO2 concentration on the growth of olive flounder (Paralichthys olivaceus) larvae. Newly hatched larvae were reared in three different concentrations of CO2 (574, 988 and 1297 μatm CO2) in temperature-controlled water tanks until metamorphosis (4 weeks). Body lengths, weights, and the concentration of some chemical elements in larval tissue were measured at the completion of each experiment, and experiment was repeated three times in May, June, and July 2011. Results indicated that body length and weight of flounder larvae were significantly increased with increasing CO2 concentration (P < 0.05). Daily growth rates of flounder larvae were higher (0.391 mm) from the high CO2 concentration (1297 μatm) than those (0.361 mm and 0.360 mm) from the lower ones (988 and 574 μatm).The measurement on some chemical elements (Ca, Fe, Cu, Zn and Sr) in fish tissue also revealed the increasing tendency of element concentration with increasing CO2 in seawater, although statistical significance cannot be tested due to the single measurement. It suggests that there are enrichment processes of these cations in larval tissue in the low pH condition.

  18. Comparison of proteome typing and serotyping of Streptococcus parauberis isolates from olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Si Won; Jang, Ho Bin; Lee, Jung Seok; Im, Se Pyeong; Lazarte, Jassy Mary S; Seo, Jong Pyo; Lee, Woo Jai; Kim, Jae Sung; Jung, Tae Sung

    2015-11-01

    The olive flounder (Paralichthys olivaceus) is a cultivated marine species that is economically important in Korea and Japan. Several bacterial pathogens have caused severe mortalities in farmed olive flounder, especially Streptococcus parauberis. We collected 145 S. parauberis isolates from diseased olive flounders from 2003 to 2008 in Jeju Island, South Korea and characterized them by Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI TOF MS) and by serology. The serological analysis divided the isolates into serotype I (62.1%) and serotype II (36.6%) and the proteome analysis divided the isolates into cluster 1 (43.4%) and cluster 2 (56.6%). All cluster 1 isolates had serotype I, but cluster 2 consisted of serotype I (32.9%), serotype II (64.6%), and others (2.5%). Further detailed analysis of the mass spectra led to identification of several specific m/z peaks that enabled discrimination between cluster 1 and 2 and between serotype I and II within cluster 2. Our results suggest that MALDI TOF MS analysis has potential as an alternative method for the rapid and reliable identification of the fish pathogen S. parauberis.

  19. Single nucleotide polymorphism of FSHβ gene associated with reproductive traits in Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    He, Feng; Wen, Haishen; Yu, Dahui; Li, Jifang; Shi, Bao; Chen, Caifang; Zhang, Jiaren; Jin, Guoxiong; Chen, Xiaoyan; Shi, Dan; Yang, Yanping

    2010-12-01

    Follicle stimulating hormone β (FSHβ) of Japanese flounder ( Paralichthys olivaceus) plays a key role in the regulation of gonadal development. This study aimed to investigate molecular genetic characteristics of the FSHβ gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of FSHβ on reproductive traits in Japanese flounder. We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the FSHβ gene in 60 individuals. We identified only an SNP (T/C) in the coding region of exon3 of FSHβ. The SNP (T/C) did not lead to amino acid changes at the position 340 bp of FSHβ gene. Statistical analysis showed that the SNP was significantly associated with testosterone (T) level and gonadosomatic index (GSI) ( P < 0.05). Individuals with genotype TC of the SNP had significantly higher serum T levels and GSI ( P < 0.05) than that of genotype CC. Therefore, FSHβ gene could be a useful molecular marker in selection for prominent reproductive trait in Japanese Flounder.

  20. Molecular cloning and sexually dimorphic expression of wnt4 in olive flounder (Paralichthys olivaceus).

    PubMed

    Weng, Shenda; You, Feng; Fan, Zhaofei; Wang, Lijuan; Wu, Zhihao; Zou, Yuxia

    2016-08-01

    WNT4 (wingless-type MMTV integration site family, member 4) is regarded as a key regulator of gonad differentiation in mammalians. However, the potential role of wnt4 in teleosts during gonad differentiation and development is still unclear. The full-length cDNA sequence of wnt4 in olive flounder (Paralichthys olivaceus) was obtained using RACE (rapid amplification of cDNA ends) technique. The wnt4 ORF contains 1059 nucleotides, encoding a protein with a signal peptide domain and a wnt family domain. Expression in tissues of adult flounders was analyzed by real-time RT-PCR. The results showed that wnt4 was widely expressed in multiple tissues of flounders, and the expression level was significantly higher in ovary than in testis. Then wnt4 expression pattern was investigated during gonadal differentiation period and at gonadal development stages (I-V). The results showed the expression levels were significantly higher in testis than in ovary during gonadal differentiation. Notably, wnt4 expression had a very significant increase before testis differentiation. At gonad different developmental stages, there was no expression signal at stage I or stage II, and the expression of wnt4 was much stronger in ovary than in testis at stage III and stage IV, followed by a faint expression in stage V in both sexes. Our results imply that cloned wnt4 could be wnt4a. It is a sex-related gene and its expression pattern in gonadal differentiation period of flounder is different from that in mammalians or other teleosts. Flounder wnt4 might play more important role in testis than in ovary during gonadal differentiation.

  1. Development of a multiplex PCR assay to detect Edwardsiella tarda, Streptococcus parauberis, and Streptococcus iniae in olive flounder (Paralichthys olivaceus).

    PubMed

    Park, Seong Bin; Kwon, Kyoung; Cha, In Seok; Jang, Ho Bin; Nho, Seong Won; Fagutao, Fernand F; Kim, Young Kyu; Yu, Jong Earn; Jung, Tae Sung

    2014-01-01

    A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea.

  2. Lectin histochemistry of Kudoa septempunctata genotype ST3-infected muscle of olive flounder (Paralichthys olivaceus)

    PubMed Central

    Kang, Jaeyoun; Park, Changnam; Jang, Yeounghwan; Ahn, Meejung; Shin, Taekyun

    2016-01-01

    The localization of carbohydrate terminals in Kudoa septempunctata ST3-infected muscle of olive flounder (Paralichthys olivaceus) was investigated using lectin histochemistry to determine the types of carbohydrate sugar residues expressed in Kudoa spores. Twenty-one lectins were examined, i.e., N-acetylglucosamine (s-WGA, WGA, DSL-II, DSL, LEL, STL), mannose (Con A, LCA, PSA), galactose/N-acetylgalactosamine (RCA12, BSL-I, VVA, DBA, SBA, SJA, Jacalin, PNA, ECL), complex type N-glycans (PHA-E and PHA-L), and fucose (UEA-I). Spores encased by a plasmodial membrane were labeled for the majority of these lectins, with the exception of LCA, PSA, PNA, and PHA-L. Four lectins (RCA 120, BSL-I, DBA, and SJA) belonging to the galactose/N-acetylgalactosamine group, only labeled spores, but not the plasmodial membrane. This is the first confirmation that various sugar residues are present in spores and plasmodial membranes of K. septempunctata ST3. PMID:27169676

  3. Hematological Responses, Survival, and Respiratory Exchange in the Olive Flounder, Paralichthys olivaceus, during Starvation

    PubMed Central

    Park, I.-S.; Hur, J. W.; Choi, J. W.

    2012-01-01

    A 12-wk experiment was conducted to examine the hematological changes, survival, and respiratory exchange in the olive flounder, Paralichthys olivaceus, during starvation. The growth, survival and respiratory exchange rates of the starved group were lower than those of the fed group during the experiment. Blood analysis, including hematocrit, hemoglobin, red blood cells, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and mean corpuscular volume, did not differ significantly (p>0.05) between the fed and starved groups at the end of the experiment. There were no significant differences in plasma cortisol, glucose, Na+, Cl−, K+, or aspartate aminotransferase between the fed and starved groups (p>0.05). Alanine aminotransferase levels were higher in the starved group than in the fed group, whereas plasma osmolality was lower in the starved group than in the fed group. It was shown that starved fish had various problems after four weeks, which did not occur in the fed group. Long-term starvation is infrequent in aquaculture farms. However, starvation studies of this kind are very useful for a basic understanding of how physiological changes affect fish health, life expectancy, and growth. PMID:25049691

  4. Cloning and expression analysis of three novel CC chemokine genes from Japanese flounder (Paralichthys olivaceus).

    PubMed

    Zou, Gang-gang; Nozaki, Reiko; Kondo, Hidehiro; Hirono, Ikuo

    2014-10-01

    Chemokines are small cytokines secreted by various cell types. They not only function in cell activation, differentiation and trafficking, but they also have influences on many biological processes. In this study, three novel CC chemokine genes Paol-SCYA105, 106 and 107 in Japanese flounder (Paralichthys olivaceus) were cloned and characterized. Paol-SCYA105 was mainly detected in gill, kidney and spleen, Paol-SCYA106 was detected in all tissues examined and Paol-SCYA107 was mainly detected in the spleen and kidney. Paol-SCYA105 and Paol-SCYA106 gene expressions peaked in kidney at day 3 after viral hemorrhagic septicemia virus infection and decreased at day 6, but Paol-SCYA106 still remained at a high level at day 6. Paol-SCYA107 gene expression was significantly up-regulated in kidney at day 6 after viral hemorrhagic septicemia virus infection. In response to infection by Gram-negative Edwardsiella tarda and Gram-positive Streptococcus iniae in kidney, only Paol-SCYA106 gene expression significantly increased. Together, these results indicate that these three novel CC chemokines are involved in the immune response against pathogen infections.

  5. Evolution history of duplicated smad3 genes in teleost: insights from Japanese flounder, Paralichthys olivaceus

    PubMed Central

    Du, Xinxin; Liu, Yuezhong; Liu, Jinxiang; Zhang, Quanqi

    2016-01-01

    Following the two rounds of whole-genome duplication (WGD) during deuterosome evolution, a third genome duplication occurred in the ray-fined fish lineage and is considered to be responsible for the teleost-specific lineage diversification and regulation mechanisms. As a receptor-regulated SMAD (R-SMAD), the function of SMAD3 was widely studied in mammals. However, limited information of its role or putative paralogs is available in ray-finned fishes. In this study, two SMAD3 paralogs were first identified in the transcriptome and genome of Japanese flounder (Paralichthys olivaceus). We also explored SMAD3 duplication in other selected species. Following identification, genomic structure, phylogenetic reconstruction, and synteny analyses performed by MrBayes and online bioinformatic tools confirmed that smad3a/3b most likely originated from the teleost-specific WGD. Additionally, selection pressure analysis and expression pattern of the two genes performed by PAML and quantitative real-time PCR (qRT-PCR) revealed evidence of subfunctionalization of the two SMAD3 paralogs in teleost. Our results indicate that two SMAD3 genes originate from teleost-specific WGD, remain transcriptionally active, and may have likely undergone subfunctionalization. This study provides novel insights to the evolution fates of smad3a/3b and draws attentions to future function analysis of SMAD3 gene family. PMID:27703851

  6. Immigration, settlement and mortality of flounder ( Paralichthys olivaceus) larvae and juveniles in a nursery ground, Shijiki bay, Japan

    NASA Astrophysics Data System (ADS)

    Tanaka, M.; Goto, T.; Tomiyama, M.; Sudo, H.

    The occurrence, distribution and abundance of larvae and juveniles of a Japanese flounder, Paralichthys olivaceus, were investigated in Shijiki Bay, south-western Japan, from 1982 through 1987, with special reference to immigration, settlement and mortality in this nursery ground. Sampling for pelagic larvae and settling and settled juveniles revealed that immigration and settlement occur during the late phase of metamorphosis, when flounders immigrate from coastal waters and settle in the near-shore sandy nursery area. Immigration of metamorphosing larvae begins in early April and continues until early June. The recruitment of flounders into the nursery ground was found to occur in several distinct phases, coinciding with spring tides. The semi-lunar periodicity found in the immigration of flounders may be due to the combination of landward tidal currents during spring tides and the tide-related vertical movements of metamorphosing flounders. Population size appeared to decrease rapidly during the first week after settlement, when lengths ranged from 11 to 14 mm. Field evidence demonstrated that heavy mortality may occur during the early phases of settlement, the extent depending on annual flounder densities and food abundance. Cannibalism of early-settled larger flounders on late-settled smaller flounders seemed to occur frequently in the nursery ground, and was more likely to occur under conditions of food deficiency and higher population densities. Thus, predation related t starvation could be one of the most important future research targets in determining recruitment dynamics in nursery areas.

  7. Transcriptome analysis of vertebral bone in the flounder, Paralichthys olivaceus (Teleostei, Pleuronectiformes), using Illumina sequencing.

    PubMed

    Ibaraki, Harumi; Wu, Xiaoming; Uji, Susumu; Yokoi, Hayato; Sakai, Yoshifumi; Suzuki, Tohru

    2015-12-01

    The processes underlying vertebral development in teleosts and tetrapods differ markedly in a variety of ways. At present, the molecular basis of teleost vertebral development and growth is poorly understood. Understanding vertebral development at the molecular level is important for aquaculture to prevent vertebral anomalies that can arise from a variety of factors, including excess vitamin A (all-trans retinol, VA) in the diet. To facilitate studies on teloest vertebral development, we performed transcriptome analysis of four month old flounder, Paralichthys olivaceus, vertebrae using next-generation sequencing. Expression profile obtained demonstrates that some members of the hh, bmp, fgf, wnt gene families, and their receptors, hox, pax, sox, dlx and tbx gene families and ntl, which are known to function in notochord and somite development in embryos, are expressed in the vertebrae. It was also showed that in addition to the retinoic acid receptor (Rar), the vertebrae express alcohol dehydrogenase 1 and retinal dehydrogenase 2 which convert VA to all-trans-retinoic acid (RA). The assembled contigs also included cytochrome p450 family members, which inactivate RA, as well as phosphatidylcholine-retinol O-acetyltransferase, which converts VA to all-trans-retinyl ester, a stock form of VA. These data suggest that in teleost vertebrae, expression of various signals and transcription factors which function in the notochord and somite development is maintained until adult stage, and RA metabolism and signaling are active to regulate transcription of RA-responsible genes, such as hedgehog and hox genes. This is the first transcriptome analysis of teleost fish vertebrae.

  8. Immunization of olive flounder (Paralichthys olivaceus) with an auxotrophic Edwardsiella tarda mutant harboring the VHSV DNA vaccine.

    PubMed

    Choi, Seung Hyuk; Kim, Min Sun; Kim, Ki Hong

    2012-09-01

    The aims of the present study were to find more powerful promoter for DNA vaccines in olive flounder (Paralichthys olivaceus) and to evaluate the availability of the auxotrophic Edwardsiella tarda mutant (Δalr Δasd E. tarda) as a delivery vehicle for DNA vaccine against VHSV in olive flounder. The marine medaka (Oryzias dancena) β-actin promoter was clearly stronger than cytomegalovirus (CMV) promoter when the vectors were transfected to Epithelioma papulosum cyprini (EPC) cells or injected into the muscle of olive flounder, suggesting that marine medaka β-actin promoter would be more appropriate promoter for DNA vaccines in olive flounder than CMV promoter. Olive flounder immunized with the Δalr Δasd E. tarda harboring viral hemorrhagic septicemia virus (VHSV) DNA vaccine vector driven by the marine medaka β-actin promoter showed significantly higher serum neutralization titer and higher survival rates against challenge with VHSV than fish immunized with the bacteria carrying VHSV DNA vaccine vector driven by CMV promoter. These results indicate that auxotrophic E. tarda mutant harboring marine medaka β-actin promoter-driven DNA vaccine vectors would be a potential system for prophylactics of infectious diseases in olive flounder.

  9. Toxicity and dose determination of quillaja saponin, aluminum hydroxide and squalene in olive flounder (Paralichthys olivaceus).

    PubMed

    Vinay, Tharabenahalli-Nagaraju; Park, Chang-Su; Kim, Heung-Yun; Jung, Sung-Ju

    2014-03-15

    Adjuvants are substances added to vaccines to enhance the immune response of a given antigen. Most of the adjuvants are toxic at certain doses, and toxicity varies in different species. Moreover, there are no standard dosage limits set for adjuvant use in fish vaccines. We evaluated the acute toxicity, serum enzymes (AST/ALT) indicating hepatic injury and histopathological changes due to intra-peritoneal administration of different concentrations of a panel of adjuvants including quillaja saponin, aluminum hydroxide, squalene emulsion and Freund's incomplete adjuvant (FIA) with a dose ranging study of saponin (500, 160, 50, 16 and 5μgfish(-1)), aluminum hydroxide (5000, 1600, 500, 160 and 50μgfish(-1)), squalene emulsion (20, 10 and 5%), and FIA to determine the acceptable dosage for vaccination in olive flounder (Paralichthys olivaceus) fingerlings measuring 4.66±0.41g, 8.47±0.42cm. Saponin was highly toxic with a LD50 of approximately 105μgfish(-1) (22.4mgkg(-1)) causing severe histological damage and AST level was high at dose above 16μgfish(-1) and ALT, specific for liver damage was high only at 160μgfish(-1) (11U/L) and was safe at 5μgfish(-1). Aluminum hydroxide was toxic at 5000μgfish(-1) and was acceptable at dose below 1600μgfish(-1) with moderate histology and AST/ALT levels similar with control. Squalene emulsion showed increased inflammation at 20% and 10% emulsions and the inflammatory response was mild at a concentration of 5% oil emulsion and AST/ALT levels being similar to control in 10% and 5% emulsions and elevated in 20% on both sampling days. FIA was not lethal, but induced severe inflammation at injection site and around blood vessels. In comparison to FIA, saponin found to be safe at dose of 5μgfish(-1), aluminum hydroxide below 1600μgfish(-1), and squalene at 5% emulsion and could be accepted for vaccination studies. These results provide an insight for the selection of safer dose of adjuvants for intra-peritoneal vaccination of

  10. Detection of lymphocystis disease virus in Japanese flounder Paralichthys olivaceus and other marine teleosts from northern China

    NASA Astrophysics Data System (ADS)

    Zhan, Wenbin; Li, Yongqin; Sheng, Xiuzhen; Xing, Jing; Tang, Xiaoqian

    2010-11-01

    We isolated a strain of lymphocystis disease virus (LCDV) from Japanese flounder ( Paralichthys olivaceus) cultured in northern China. Based on published sequences of major capsid protein (MCP) gene of LCDV-cn (GenBank: AF126405), we designed two primer sets P1/P2 and P3/P4. We then used one-step or nested PCR and in-situ hybridization (ISH) to detect LCDV and identify the target tissues or cells in infected Japanese flounder. The PCR products were positive in purified viral supernatant, skin nodules, gut, gill, kidney, spleen, stomach, heart, and liver of Japanese flounder. We compared the DNA sequence with 14 MCP nucleotide sequences from GenBank, including Megalocytivirus (OFIV and RSIV), Iridovirus (CzIV and WIV), Ranavirus (TFV and FV3), and Lymphocystivirus (8 LCDV). Based on the alignment, we confirmed the PCR product was from Lymphocystivirus (GenBank accession number DQ279090 (LCDV-HD)). Using ISH, we noted the presence of LCDV in the skin nodules, gut, gill, spleen, stomach, and heart of spontaneously infected Japanese flounders. We successfully amplified LCDV fragments from Schlegel’s black rockfish ( Sebastes schlegeli Higendorf), redwing sea robin ( Lepidotrigla microptera Günther) and turbot ( Scophthalmus maximus) using the one-step and nested PCR, suggesting the target genes can be widely detected in fish using this method.

  11. cDNA clone and expression analysis of α-Tropomyosin during Japanese flounder (Paralichthys olivaceus) metamorphosis.

    PubMed

    Zhang, Hong-Mei; Su, Yan-Fang; Shi, Zhi-Yi; Fu, Yuan-Shuai

    2014-07-01

    Tropomyosin (TM) plays a critical role in skeletal and cardiac muscle development and function. To assess the functional significance of α-TM in Japanese flounder (Paralichthys olivaceus) development and metamorphosis, cDNA from Japanese flounder was cloned and α-TM mRNA measured during development and metamorphosis. The full-length cDNA is 1 191 bp, including a 5'-untranslated region of 114 bp, a 3'-UTR of 222 bp, and an open reading frame of 855 bp encoding a polypeptide of 284 amino acids. Real-time quantitative PCR revealed that α-TM mRNA is initially expressed in unfertilized ovum, indicating the α-TM gene is maternal. Relatively low mRNA levels were observed in different embryonic stages. A higher level of α-TM mRNA was detected 3 days post hatching (dph), while the highest level was measured at 29 dph (metamorphic climax) after which it declined towards the end of metamorphosis. The expression of α-TM mRNA was up-regulated in thyroid hormone-treated larvae at 36 dph, but there was no marked difference at other stages when compared to control animals. After thiourea treatment, the expression of α-TM mRNA declined slightly. These data provide basic information that can be utilized in further studies into the role of α-TM in P. olivaceus development and metamorphosis.

  12. Cloning and expression of partial Japanese flounder (Paralichthys olivaceus) IgD.

    PubMed

    Choi, Dae-Han; Jang, Han-Na; Ha, Dae-Mang; Kim, Jae-Wha; Oh, Chan-Ho; Choi, Sang-Hoon

    2007-07-31

    The cDNA sequence of the Japanese flounder (Paralychthys olivaceus) IgD has been previously reported (GenBank accession no. AB052658) and this was followed by the detection of IgD mRNA expression in some flounder organ tissues. However, it has not been determined whether the flounder IgD gene is virtually expressed into IgD protein. To characterize the flounder immunoglobulins utilized in elucidating the mechanism, evolution and diversity of the flounder immune system, antibodies specific to IgD and IgM were necessary. In the present study, partial flounder recombinant IgD (rIgD), IgM (rIgM) and the conserved regions of IgD and IgM (rCIg) were produced by cloning the cDNA sequence using isotype specific primers which were designed to produce unique fragments of IgD and IgM specific amino acid sequences. The production of recombinant Igs was ascertained by SDS-gel electrophoresis and immunoblot analysis using anti-T7 d Taq antibody. The produced recombinant Igs were purified using affinity columns, and used as immunogens. Antibodies specific to the isotype of flounder Igs were generated by immunizing rabbits with rfIgs and the antibodies produced were identified by enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Specificities of the generated antibodies were evaluated by testing cross-reactivity between recombinant IgM and IgD. By ELISA, rabbit antibodies against the rfIgD fragment (anti-rfIgD) failed to recognize any kind of flounder serum Igs, whereas respective antibodies against rfCIg (anti-rfCIg) and rfIgM fragments (anti-rfIgM) reacted with serum Igs. Likewise, in immunoblot assays, though anti-rfIgD did not, both anti-rfCIg and anti-rfIgM bound with the ~85 kd flounder IgM heavy chain. By flow cytometry analysis, anti-rfCIg, anti-rfIgD and anti-rfIgM reacted with 6%, 3% and 6.5% of cells, respectively, suggesting that flounder IgD is not secreted in serum but expressed on flounder B-like cell surfaces as in mammals. Antibodies produced against

  13. Origin of adult-type pigment cells forming the asymmetric pigment pattern, in Japanese flounder (Paralichthys olivaceus).

    PubMed

    Yamada, Toshiyuki; Okauchi, Masanori; Araki, Kazuo

    2010-12-01

    The flatfish-specific asymmetric pigment pattern depends on the asymmetric appearance of adult-type pigment cells after the late metamorphic stages. To understand the mechanism enabling the formation of this asymmetric pattern, we investigated the behavior of pigment cell latent precursors in postembryonic Japanese flounder, Paralichthys olivaceus, by analysis of the expression patterns of pigment lineage markers (colony stimulating factor 1 receptor, dopachrome tautomerase, kit) and the DiI (DiO) labeling test for latent precursors. We found that, throughout the larval stages, pigment cell latent precursors were predominantly localized along the dorsal and ventral margins of the flank symmetrically and migrated continuously from these regions to the lateral sides symmetrically, and after late metamorphic stages these precursors differentiated into adult-type pigment cells on the lateral side asymmetrically. We conclude that adult-type pigment cells that form the asymmetric pigment pattern are continuously derived from the dorsal and ventral margins of the flank during larval development.

  14. The stimulatory effect of neuropeptide Y on growth hormone expression, food intake, and growth in olive flounder (Paralichthys olivaceus).

    PubMed

    Li, Meijie; Tan, Xungang; Sui, Yulei; Jiao, Shuang; Wu, Zhihao; Wang, Lijuan; You, Feng

    2017-02-01

    Neuropeptide Y (NPY) is a 36-amino acid peptide known to be a strong orexigenic (appetite-stimulating) factor in many species. In this study, we investigated the effect of NPY on food intake and growth in the olive flounder (Paralichthys olivaceus). Recombinant full-length NPY was injected intraperitoneally into olive flounder at the dose of 1 μg/g body weight; phosphate buffered saline was used as the negative control. In a long-term experiment, NPY and control groups were injected every fifth day over a period of 30 days. In a short-term experiment, NPY and control groups were given intraperitoneal injections and maintained for 24 h. Food intake and growth rates were significantly higher in fish injected with recombinant NPY than in the control fish (P < 0.05). Higher growth hormone (GH) and NPY mRNA transcript levels were observed in both experiments, indicating a stimulatory effect of NPY on GH release. These findings demonstrate that NPY is an effective appetite-stimulating factor in olive flounder with the potential to improve the growth of domestic fish species and enhance efficiency in aquaculture.

  15. Post-release feeding and growth of hatchery-reared Japanese flounder Paralichthys olivaceus: relevance to stocking effectiveness.

    PubMed

    Tomiyama, T; Watanabe, M; Kawata, G; Ebe, K

    2011-05-01

    The feeding and growth of hatchery-reared (HR) Japanese flounder Paralichthys olivaceus of c. 100 mm total length (L(T) ) released off the coast of Fukushima, Japan, were investigated. From 2 to 15 days after release, the HR P. olivaceus frequently exhibited high empty-stomach frequency (>40%), low stomach-content mass (<1% of body mass), reduced somatic condition from release (c.-10%) and negligible growth. Thereafter, empty-stomach frequency decreased, the stomach-content mass of HR fish increased to 2-8% of body mass, the somatic condition recovered and growth rate increased to 0·5-1·5 mm day(-1) . Prey items were initially mysids, shifting thereafter to fishes such as the Japanese anchovy Engraulis japonica, as observed similarly in wild counterparts. The proportion of mysids decreased with time after release irrespective of size at release, indicating the importance of mysids for adaptation to natural food. Recapture rates at age 1 year, derived from fish market surveys, varied greatly among release years (4-11%). The variation in the recapture rates was largely accounted for by the post-release growth rates (r(2) = 0·5), suggesting a relationship between the post-release growth of HR fish and their survival and subsequent stocking effectiveness.

  16. Mutations in exons of the CYP17-II gene affect sex steroid concentration in male Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Ma, Ruiqin; He, Feng; Wen, Haishen; Li, Jifang; Shi, Bao; Shi, Dan; Liu, Miao; Mu, Weijie; Zhang, Yuanqing; Hu, Jian; Han, Weiguo; Zhang, Jianan; Wang, Qingqing; Yuan, Yuren; Liu, Qun

    2012-03-01

    As a specific gene of fish, cytochrome P450c17-II ( CYP17-II) gene plays a key role in the growth, development an reproduction level of fish. In this study, the single-stranded conformational polymorphism (SSCP) technique was used to characterize polymorphisms within the coding region of CYP17-II gene in a population of 75 male Japanese flounder ( Paralichthys olivaceus). Three single nucleotide polymorphisms (SNPs) were identified in CYP17-II gene of Japanese flounder. They were c.G594A (p.G188R), c.G939A and c.G1502A (p.G490D). SNP1 (c.G594A), located in exon 4 of CYP17-II gene, was significantly associated with gonadosomatic index (GSI). Individuals with genotype GG of SNP1 had significantly lower GSI ( P < 0.05) than those with genotype AA or AG. SNP2 (c.G939A) located at the CpG island of CYP17-II gene. The mutation changed the methylation of exon 6. Individuals with genotype AA of SNP2 had significantly lower serum testosterone (T) level and hepatosomatic index (HSI) compared to those with genotype GG. The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder. However, the SNP3 (c.G1502A) located in exon 9 did not affect the four measured reproductive traits. This study showed that CYP17-II gene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.

  17. Comparison of growth characteristics between skeletal muscle satellite cell lines from diploid and triploid olive flounder Paralichthys olivaceus

    PubMed Central

    Wu, Zhi-hao; Tan, Xungang; Jiao, Shuang; Zhang, Pei-jun

    2016-01-01

    Objectives. According to myosatellite cell lines (MSCs) established in vitro from diploid and triploid flounder, we compared the characters of growth and differentiation of their MSCs. The results would be useful for learning the muscle development mechanism in teleosts. Materials and Methods. The skeletal muscle cells from the diploid and triploid olive flounder Paralichthys olivaceus were isolated and cultured in vitro, respectively, and the cells were characterized at the morphology and molecular level; meanwhile, the performance of these cells’ proliferation and differentiation were analyzed. Results. Two new skeletal muscle cell lines (POMSCS(2n) and POMSCS(3n)) from diploid and triploid flounder have been respectively subcultured for 67 times and 66 times. The cultured cells were mostly spindle-like mononuclear cells. They have normal flounder diploid karyotype (2n=48t) and triploid karyotype (3n=72t), respectively. Muscle satellite cell gene marker (pax7b) and myogenic cell protein marker (Desmin) were all expressed in cells of two cell lines. Both of the cells could differentiate into the large polynucleated muscle fibre cells, and immunofluorescence reactions of myosin heavy chain (MyHC) were positive. There were more cells of POMSCS(3n) to differentiate into the muscle fibre cells than that of POMSCS(2n). However, POMSCS(2n) cells proliferated more rapidly than those of POMSCS(3n) (P < 0.05). The significant fluorescent signals were observed in both POMSCS(2n) and POMSCS(3n) cells after transfected with pEGFP-N3 reporter plasmid. Conclusions. The two cell lines have been established and characterized as MSCs. We suppose that it might be the differentiation capacity, rather than the proliferation activity of MSCs to play a key role in the better growth of triploid ones than diploid. Both cell lines will become the ideal tools to learn the mechanism of fish MSCs proliferation, differentiation and regeneration during muscle development in the future. PMID

  18. Effects of dietary soy isoflavones on feed intake, growth performance and digestibility in juvenile Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Mai, Kangsen; Zhang, Yanjiao; Chen, Wei; Xu, Wei; Ai, Qinghui; Zhang, Wenbing

    2012-12-01

    An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake, growth performance, and digestion of juvenile Japanese flounder ( Paralichthys olivaceus). Four isonitrogenous (49% crude protein) and isoenergetic (20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones, namely, 0, 1, 4 and 8 g soy isoflavones in 1 kg of diet. Each diet was randomly fed to triplicate tanks of fish (Initial average weight: 2.58 g ± 0.01 g), and each tank was stocked with 35 fish. No significant difference was observed among diets with levels of 0, 1 and 4 g kg-1 soy isoflavones in feed intake, weight gain, feed efficiency ratio (FER), proximate composition of fish whole body and apparent digestibility coefficients (ADC) of nutrients and energy ( P>0.05). However, high dietary soy isoflavones level (8 g kg-1) significantly depressed weight gain, FER, whole-body crude lipid content of fish and ADC of nutrients ( P<0.05). These results indicate that high level of dietary soy isoflavones (above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder. However, as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1, the adverse effects might be neglected when soybean products are used as a fish feed ingredient.

  19. Effects of CO2-induced ocean acidification on the growth of the larval olive flounder Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Kim, Kyung-Su; Shim, Jeong Hee; Kim, Suam

    2015-06-01

    It widely thought that ocean acidification processes that caused by atmospheric CO2 increase and accordingly lower seawater pH conditions might cause serious harm to marine food webs in certain ecosystems in the near future. Little is known about how marine fishes respond to reduced pH conditions. We investigated the effects of CO2 conditions on the growth of olive flounder ( Paralichthys olivaceus) larvae. Newly hatched larvae were reared at three different levels of pCO2 (574, 988 and 1297 µatm) in temperature-controlled (21 ± 0.5°C) water tanks for four weeks until metamorphosis. The experiment was repeated three times in May, June, and July 2011, and body lengths and weights were measured at the completion of each experiment. The results indicated that the body length and weight of flounder larvae significantly increased with increasing CO2 concentrations (P < 0.05). A higher daily growth rate during the early larval stage (hatching to 14 days) was found among the larvae reared in low pCO2 conditions, while a significantly lower growth rate was found among larvae in higher pCO2 water conditions. On the other hand, in the late larval stage (18 days after hatching to metamorphosis), the daily growth rate of larvae was much higher in high CO2 water. Bone density of larvae, however, decreased with increasing CO2 concentration in the water

  20. An outbreak of VHSV (viral hemorrhagic septicemia virus) infection in farmed Japanese flounder Paralichthys olivaceus in Japan.

    PubMed

    Isshik, T; Nishizawa, T; Kobayashi, T; Nagano, T; Miyazaki, T

    2001-11-08

    A rhabdoviral disease occurred in farmed populations of market sized Japanese flounder (hirame) Paralichthys olivaceus in the Seto Inland Sea of Japan in 1996. The causative agent was identified as viral hemorrhagic septicemia virus (VHSV) based on morphological, immunological, and genetic analyses. Diseased fish that were artificially injected with a representative virus isolate showed the same pathological signs and high mortality as observed in the natural outbreak. This is the first report of an outbreak of VHSV infection in cultured fish in Japan. Clinical signs of diseased fish included dark body coloration, an expanded abdomen due to ascites, congested liver, splenomegaly, and a swollen kidney. Myocardial necrosis was most prominent and accompanied by inflammatory reactions. Necrotic lesions also occurred in the liver, spleen and hematopoietic tissue, and were accompanied by circulatory disturbances due to cardiac failure. Hemorrhagic lesions did not always appear in the lateral musculature. Transmission electron microscopy revealed many rhabdovirus particles and associated inclusion bodies containing nucleocapsids in the necrotized myocardium. The histopathological findings indicated that the necrotizing myocarditis could be considered a pathognomonic sign of VHSV infection in Japanese flounder.

  1. Comparison of antigenic proteins from Lactococcus garvieae KG- and KG+ strains that are recognized by olive flounder (Paralichthys olivaceus) antibodies.

    PubMed

    Shin, Gee-Wook; Nho, Seong-Won; Park, Seong-Bin; Jang, Ho-Bin; Cha, In-Seok; Ha, Mi-Ae; Kim, Young-Rim; Dalvi, Rishikesh S; Joh, Seong-Joon; Jung, Tae-Sung

    2009-10-20

    Lactococcus garvieae is an important etiological agent of lactococcosis in various fish species including olive flounder (Paralichthys olivaceus). In this study, proteomic and immunoproteomic analyses were employed to compare the antigenic profiles of strains KG9408, MS93003, and NSS9310 strains of L. garvieae. Proteomic analysis using two-dimensional gel electrophoresis (2-DE) revealed differences in five protein spots among the different L. garvieae strains. In immunoproteomic analysis, there was a significant difference in the 2-DE immunoblot profiles of the L. garvieae strains using sera collected from fish surviving infection with either L. garvieae strains KG9408 or NSS9310. These sera reacted with 8 and 7 unique antigenic protein spots, respectively. Heat shock protein (HSP) 70 and DNA-directed RNA polymerase were among the specific antigens recognized by the anti-NSS9310 serum. In addition, the anti-NSS9310 and anti-KG9408 olive flounder sera reacted with 25 common antigenic protein spots of all the L. garvieae strains, which included elongation factor (EF)-Tu, arginine deiminase (AD), inosine-5'-monophosphate dehydrogenase (IMPD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphomannomutase (PMM), L-lactate dehydrogenase (L-LDH), 6-phosphofructokinase and UDP-galactose 4-epimerase (UDP-galactose). Based on the present results, the 8 antigens recognized by the anti-KG9408 serum and the 25 common antigens recognized by both sera may serve as potential markers for developing an effective vaccine against this bacterium.

  2. Histopathological changes of Korea cultured olive flounder, Paralichthys olivaceus due to scuticociliatosis caused by histophagous scuticociliate, Philasterides dicentrarachi.

    PubMed

    Jin, Chang-Nam; Harikrishnan, Ramasamy; Moon, Young-Gun; Kim, Man-Chul; Kim, Ju-Sang; Balasundaram, Chellam; Azad, I S; Heo, Moon-Soo

    2009-05-12

    Recently, mass mortality due to histophagous scuticociliate, Philasterides dicentrarachi in olive flounder, Paralichthys olivaceus occurred in aquaculture farms of Jeju Island, South Korea. We have artificially induced infection through immersion on day 12, the density of ciliates slowly decreased in the experimental tanks; on day 28 to 2300cells/ml in 3cm group and 1800cells/ml in 5cm group. The survival rate of P. olivaceus on days 24 and 28 of infection in the 3cm group was decreased to 4 and 6, respectively; however, no mortality was recorded in the 5cm group. In the control group 100% survival in the chosen period of both groups occurred except in the 3cm group whereas on days 24 and 28 the death rate was 1 and 2, respectively. Many ciliates with ingested red blood cells were observed in the gills, skeletal muscle, skin, fins and brains of infected flounder. The parasites were also observed in the lamina propria of the digestive tract, pharynx, peritoneal fluid, cerebrospinal fluid and cornea. Histopathological and inflammatory changes were characterized by swelling and generalized erythema and muscle tissue necrosis. Affected fish showed varying levels of tissue damage including severe epidermal and dermal necrotic lesions. Loss of scales, appearance of bleached spots that coalesced to form brownish patches, haemorrhagic and severe dermal necrotic lesions were the major clinico-pathological manifestations. The parasite was also seen distributed extensively in the entire brain causing widespread nerve necrosis after a prolonged period of infection. These results appear to support the hypothesis that the P. dicentrarchi may be penetrating via the gills or the skin, and then travel via the bloodstream to other parts of the body, including the body cavity.

  3. Quantitative trait loci detection of Edwardsiella tarda resistance in Japanese flounder Paralichthys olivaceus using bulked segregant analysis

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoxia; Xu, Wenteng; Liu, Yang; Wang, Lei; Sun, Hejun; Wang, Lei; Chen, Songlin

    2016-11-01

    In recent years, Edwardsiella tarda has become one of the most deadly pathogens of Japanese flounder ( Paralichthys olivaceus), causing serious annual losses in commercial production. In contrast to the rapid advances in the aquaculture of P. olivaceus, the study of E. tarda resistance-related markers has lagged behind, hindering the development of a disease-resistant strain. Thus, a marker-trait association analysis was initiated, combining bulked segregant analysis (BSA) and quantitative trait loci (QTL) mapping. Based on 180 microsatellite loci across all chromosomes, 106 individuals from the F1333 (♀: F0768 ×♂: F0915) (Nomenclature rule: F+year+family number) were used to detect simple sequence repeats (SSRs) and QTLs associated with E. tarda resistance. After a genomic scan, three markers (Scaffold 404-21589, Scaffold 404-21594 and Scaffold 270-13812) from the same linkage group (LG)-1 exhibited a significant difference between DNA, pooled/bulked from the resistant and susceptible groups (P <0.001). Therefore, 106 individuals were genotyped using all the SSR markers in LG1 by single marker analysis. Two different analytical models were then employed to detect SSR markers with different levels of significance in LG1, where 17 and 18 SSR markers were identified, respectively. Each model found three resistance-related QTLs by composite interval mapping (CIM). These six QTLs, designated qE1-6, explained 16.0%-89.5% of the phenotypic variance. Two of the QTLs, qE-2 and qE-4, were located at the 66.7 cM region, which was considered a major candidate region for E. tarda resistance. This study will provide valuable data for further investigations of E. tarda resistance genes and facilitate the selective breeding of disease-resistant Japanese flounder in the future.

  4. Anesthetic Effect and Physiological Response in Olive Flounder (Paralichthys olivaceus) to Clove Oil in a Simulated Transport Experiment

    PubMed Central

    Gil, Hyun Woo; Ko, Min Gyun; Lee, Tae Ho; Park, In-Seok; Kim, Dong Soo

    2016-01-01

    The optimum concentrations of clove oil as an anesthetic for olive flounder (Paralichthys olivaceus) and the stress response of the fish to clove oil anesthesia were determined over a range of water temperatures, and investigated in a simulated transport experiment using analysis of various water and physiological parameters. While the time for induction of anesthesia decreased significantly as both the concentration of clove oil and water temperature increased, the recovery time increased significantly (P<0.05). The plasma cortisol concentration in fish at each temperature increased significantly up to 12 h following exposure (P<0.05), then decreased to 48 h (P<0.05). The DO dissolved oxygen concentrations, pH values, and the fish respiratory frequencies decreased over 6 h following exposure to clove oil in all experimental groups (P<0.05), whereas the NH4 + and CO2concentrations in all experimental groups increased up to 6 h (P<0.05). The pH values and DO concentrations increased with increasing clove oil concentration (P<0.05) in the 6 h following exposure, and the CO2 and NH4 + concentrations and the respiratory frequencies decreased with increasing clove oil concentration (P<0.05). The results of this experiment suggest that clove oil reduced the metabolic activity of olive flounder, thus reducing NH4 + excretion and O2 consumption. In conclusion, clove oil appears to be a cost-effective and efficient anesthetic that is safe for use and non-toxic to the fish and users. Its use provides the potential for improved transportation of olive flounder. PMID:27796007

  5. Anesthetic Effect and Physiological Response in Olive Flounder (Paralichthys olivaceus) to Clove Oil in a Simulated Transport Experiment.

    PubMed

    Gil, Hyun Woo; Ko, Min Gyun; Lee, Tae Ho; Park, In-Seok; Kim, Dong Soo

    2016-09-01

    The optimum concentrations of clove oil as an anesthetic for olive flounder (Paralichthys olivaceus) and the stress response of the fish to clove oil anesthesia were determined over a range of water temperatures, and investigated in a simulated transport experiment using analysis of various water and physiological parameters. While the time for induction of anesthesia decreased significantly as both the concentration of clove oil and water temperature increased, the recovery time increased significantly (P<0.05). The plasma cortisol concentration in fish at each temperature increased significantly up to 12 h following exposure (P<0.05), then decreased to 48 h (P<0.05). The DO dissolved oxygen concentrations, pH values, and the fish respiratory frequencies decreased over 6 h following exposure to clove oil in all experimental groups (P<0.05), whereas the NH4(+) and CO2concentrations in all experimental groups increased up to 6 h (P<0.05). The pH values and DO concentrations increased with increasing clove oil concentration (P<0.05) in the 6 h following exposure, and the CO2 and NH4(+) concentrations and the respiratory frequencies decreased with increasing clove oil concentration (P<0.05). The results of this experiment suggest that clove oil reduced the metabolic activity of olive flounder, thus reducing NH4(+) excretion and O2 consumption. In conclusion, clove oil appears to be a cost-effective and efficient anesthetic that is safe for use and non-toxic to the fish and users. Its use provides the potential for improved transportation of olive flounder.

  6. Immunoglobulin Tau Heavy Chain (IgT) in Flounder, Paralichthys olivaceus: Molecular Cloning, Characterization, and Expression Analyses

    PubMed Central

    Du, Yang; Tang, Xiaoqian; Zhan, Wenbin; Xing, Jing; Sheng, Xiuzhen

    2016-01-01

    Immunoglobulin tau (IgT) is a new teleost immunoglobulin isotype, and its potential function in adaptive immunity is not very clear. In the present study, the membrane-bound and secreted IgT (mIgT and sIgT) heavy chain genes were cloned for the first time and characterized in flounder (Paralichthys olivaceus), and found the nucleic acid sequence were exactly same in the Cτ1–Cτ4 constant domains of mIgT and sIgT, but different in variable regions and the C-terminus. The amino acid sequence of mIgT shared higher similarity with Bovichtus diacanthus (51.2%) and Dicentrarchus labrax (45.0%). Amino acid of flounder IgT, IgM, and IgD heavy chain was compared and the highest similarity was found between IgT Cτ1 and IgM Cμ1 (38%). In healthy flounder, the transcript levels of IgT mRNA were the highest in gill, spleen, and liver, and higher in peripheral blood leucocytes, skin, and hindgut. After infection and vaccination with Edwardsiella tarda via intraperitoneal injection and immersion, the qRT-PCR analysis demonstrated that the IgT mRNA level was significantly upregulated in all tested tissues, with similar dynamic tendency that increased firstly and then decreased, and higher in gill, skin, hindgut, liver, and stomach in immersion than in the injection group, but no significant difference existed in spleen and head kidney between immersion and injection groups. These results revealed that IgT responses could be simultaneously induced in both mucosal and systemic tissues after infection/vaccination via injection and immersion route, but IgT might play a more important role in mucosal immunity than in systemic immunity. PMID:27649168

  7. Effects of dietary soybean stachyose and phytic acid on gene expressions of serine proteases in Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Mi, Haifeng; Mai, Kangsen; Zhang, Wenbing; Wu, Chenglong; Cai, Yinghua

    2011-09-01

    Soybean stachyose (SBS) and phytic acid (PA) are anti-nutritional factors (ANF) which have deleterious effects on the growth and digestibility in fish. The present research studied the effects of dietary SBS and PA on the expression of three serine protease genes in the liver of Japanese flounder ( Paralichthys olivaceus). These genes are trypsinogen 1 (poTRY), elastase 1 (poEL) and chymotrypsinogen 1 (poCTRY). Eight artificial diets with graded levels of supplemented ANFs were formulated to 4 levels of SBS (0.00, 0.40, 0.80 and 1.50%), 4 levels of PA (0.00, 0.20, 0.40 and 0.80), respectively. Japanese flounder (initial weight 2.45 g ± 0.01 g) were fed with these diets for 10 weeks with three replications per treatment. At the end of 10 weeks, supplementation of 0.40% of dietary SBS or PA significantly increased the gene expression of poTRY and poCTRY ( P<0.05). The same level of dietary SBS significantly decreased the gene expression of poEL. In comparison with the control group (ANF-free), dietary PA (0.2% and 0.8%) significantly decreased the gene expression of poTRY, poCTRY and poEL ( P<0.05). However, excessive supplement of dietary SBS (1.5%) has no significant effects on these gene expressions ( P>0.05). These results suggested that dietary SBS and dietary PA could directly affect the serine protease genes at the transcriptional level in Japanese flounder, and these genes' expression was more sensitive to dietary PA than to SBS under the current experimental conditions.

  8. Effect of heavy oil exposure on antibacterial activity and expression of immune-related genes in Japanese flounder Paralichthys olivaceus.

    PubMed

    Song, Jun-Young; Nakayama, Kei; Kokushi, Emiko; Ito, Kazuki; Uno, Seiichi; Koyama, Jiro; Rahman, M Habibur; Murakami, Yasunori; Kitamura, Shin-Ichi

    2012-04-01

    Heavy oil (HO) pollution is one of the most important environmental issues globally. However, little is known about the immunotoxicity of HO in fish. We therefore investigated the effects of HO exposure on immunocompetence and expression of immune-related genes in Japanese flounder, Paralichthys olivaceus. To test immunocompetency, serum collected from the fish was mixed with Edwardsiella tarda, plated, and the resultant numbers of bacterial colonies were counted. Plates with serum from HO-exposed fish (5 d postexposure [dpe]) had significantly higher numbers of colonies than those of the untreated control group, suggesting that HO exposure suppresses immunocompetency. Downregulation of the immunoglobulin light chain (IgM) gene in HO-exposed fish at 5 dpe was detected by real-time polymerase chain reaction. These results suggest that IgM-mediated immunity is suppressed by HO exposure. We measured polycyclic aromatic hydrocarbon (PAH) concentrations in the liver of the fish. Low molecular weight PAHs were found to be taken up at high concentrations in fish liver; therefore, they are likely the cause of immune suppression in the fish.

  9. Distribution and expression in vitro and in vivo of DNA vaccine against lymphocystis disease virus in Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Zheng, Fengrong; Sun, Xiuqin; Liu, Hongzhan; Wu, Xingan; Zhong, Nan; Wang, Bo; Zhou, Guodong

    2010-01-01

    Lymphocystis disease, caused by the lymphocystis disease virus (LCDV), is a significant worldwide problem in fish industry causing substantial economic losses. In this study, we aimed to develop the DNA vaccine against LCDV, using DNA vaccination technology. We evaluated plasmid pEGFP-N2-LCDV1.3 kb as a DNA vaccine candidate. The plasmid DNA was transiently expressed after liposome transfection into the eukaryotic COS 7 cell line. The distribution and expression of the DNA vaccine (pEGFP-N2-LCDV1.3kb) were also analyzed in tissues of the vaccinated Japanese flounder by PCR, RT-PCR and fluorescent microscopy. Results from PCR analysis indicated that the vaccine-containing plasmids were distributed in injected muscle, the muscle opposite the injection site, the hind intestine, gill, spleen, head, kidney and liver, 6 and 25 days after vaccination. The vaccine plasmids disappeared 100 d post-vaccination. Fluorescent microscopy revealed green fluorescence in the injected muscle, the muscle opposite the injection site, the hind intestine, gill, spleen, head, kidney and liver of fish 48 h post-vaccination, green fluorescence did not appear in the control treated tissue. Green fluorescence became weak at 60 days post-vaccination. RT-PCR analysis indicated that the mcp gene was expressed in all tested tissues of vaccinated fish 6-50 days post-vaccination. These results demonstrate that the antigen encoded by the DNA vaccine is distributed and expressed in all of the tissues analyzed in the vaccinated fish. The antigen would therefore potentially initiate a specific immune response. the plasmid DNA was injected into Japanese flounder ( Paralichthys olivaceus) intramuscularly and antibodies against LCDV were evaluated. The results indicate that the plasmid encoded DNA vaccine could induce an immune response to LCDV and would therefore offer immune protection against LCD. Further studies are required for the development and application of this promising DNA vaccine.

  10. Oral immunization of olive flounder (Paralichthys olivaceus) with recombinant live viral hemorrhagic septicemia virus (VHSV) induces protection against VHSV infection.

    PubMed

    Kim, Min Sun; Kim, Dong Soo; Kim, Ki Hong

    2011-08-01

    A recombinant viral hemorrhagic septicemia virus (rVHSV-ΔNV-EGFP) that has enhanced green fluorescent protein (EGFP) gene instead of NV gene was previously generated using reverse genetics technology. In this study, potential of the rVHSV-ΔNV-EGFP to be used as a live oral vaccine candidate was assessed. The presence of the recombinant virus in internal organs of orally administered olive flounder (Paralichthys olivaceus) was analyzed by semi-quantitative RT-PCR. Although the recombinant VHSV-specific band was detected only when the number of PCR cycle was increased to 35, the band was detected from internal organs, such as kidney, spleen, and liver of fish that were reared at either 15 °C or 20 °C till even 20 days, suggesting that a few orally administered rVHSV-ΔNV-EGFP might be transported to internal organs, and might keep weak replication ability in the organs. VHSV-neutralizing activity was induced by oral immunization of olive flounder with the NV gene knock-out recombinant VHSV not only in skin and intestinal mucus but also in serum, suggesting that mucosal and systemic adaptive immune responses were elicited by oral immunization. In challenge experiment, groups of fish immunized with 10⁴, 10⁵, and 2 × 10⁵ PFU of rVHSV-ΔNV-EGFP/fish showed 25%, 50%, and 70% of relative percent survival (RPS), respectively. The RPSs were elevated to 60%, 75%, and 90% by a boost immunization in fish boost immunized with 10⁴, 10⁵, and 2 × 10⁵ PFU of rVHSV-ΔNV-EGFP, respectively. The cumulative mortality of fish in the control groups was 100%. Conclusionly, the present results demonstrate that the NV gene knock-out recombinant VHSV administered orally to olive flounder can induce dose- and boosting-dependent VHSV-neutralizing antibody in mucus and serum, and can provide a high protection in olive flounder against a virulent VHSV challenge.

  11. Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Liu, Guangxing; Xu, Donghui

    2009-12-01

    Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods ( P<0.01). Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods ( S. poplesia) had significantly higher growth rate than those fed with the other two organisms ( P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others ( P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia ( P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.

  12. The effects of combined dietary probiotics Lactococcus lactis BFE920 and Lactobacillus plantarum FGL0001 on innate immunity and disease resistance in olive flounder (Paralichthys olivaceus).

    PubMed

    Beck, Bo Ram; Kim, Daniel; Jeon, Jongsu; Lee, Sun-Min; Kim, Hui Kwon; Kim, Oi-Jin; Lee, Jae Il; Suh, Byung Sun; Do, Hyung Ki; Lee, Kwan Hee; Holzapfel, Wilhelm H; Hwang, Jee Youn; Kwon, Mun Gyeong; Song, Seong Kyu

    2015-01-01

    The effects of a dietary probiotic mixture containing Lactococcus (Lc.) lactis BFE920 isolated from bean sprout and autochthonous Lactobacillus (Lb.) plantarum FGL0001 originally isolated from the hindgut of olive flounder (Paralichthys olivaceus) were investigated for the purpose of improving the probiotic effects of Lc. lactis BFE920 on the olive flounder. The immunostimulatory, disease protective, and weight gain effects of Lc. lactis BFE920 were significantly improved when olive flounder (average weight 37.5±1.26 g) were fed the probiotic mixture (log10 7.0 CFU each/g feed pellet) for 30 days. Flounder fed the mixture showed improved skin mucus lysozyme activity and phagocytic activity of innate immune cells compared to flounder fed a single probiotic agent or a control diet. While the levels of neutrophil activity in flounder fed the single probiotic agent or the mixture were similar, they were significantly higher than levels in a control group. Additionally, probiotic-fed flounder showed significantly increased expressions of IL-6, IL-8, and TNF-α in the intestine compared to the control group. Following a 30-day period of being fed probiotics or a control diet, the olive flounder were challenged with an i.p. injection of Streptococcus iniae (log10 6.0 CFU/fish). The groups fed the mixed probiotics, Lc. lactis BFE920, Lb. plantarum FGL0001, and the control diet had survival rates of 55%, 45%, 35%, and 20%, respectively. Flounder fed the probiotic mixture gained 38.1±2.8% more body weight compared to flounder fed the control diet during the 30-day study period. These data strongly suggest that a mixture of Lc. lactis BFE920 and Lb. plantarum FGL0001 may serve as an immunostimulating feed additive useful for disease protection in the fish farming industry.

  13. Compensatory growth of juvenile brown flounder Paralichthys olivaceus following low temperature treatment for different periods

    NASA Astrophysics Data System (ADS)

    Peng, Yinhui; Liu, Xiujia; Huang, Guoqiang; Wei, Liuzhi; Zhang, Xiumei

    2017-04-01

    We investigated the effects of low temperature (8.5°C) on the growth and feeding rates and feed conversion efficiency of juvenile P. olivaceus with an average initial weight of 3.87 ± 0.06 g (mean ± SE). Fish were exposed to 8.5°C for 0 (control), 1, 2, 3 and 4 weeks, and then to 20°C for 10, 9, 8, 7 and 6 weeks, respectively. Low temperature clearly led to growth depression. The weight of fish exposed to low temperature for 1 week was restored to that of control, while that of fish exposed to low temperature longer was significantly decreased ( P < 0.05). During the entire low-temperature period, specific growth rate, feeding rate and feed conversion efficiency of the fish were significantly lower ( P < 0.05) than those of control, while in the whole recovery period, specific growth and average feeding rate were markedly higher ( P < 0.05) than those of control. At the end of experiment, only the feeding rate of the fish exposed to low temperature for 1 week was not significantly different from that of control ( P > 0.05). Feeding rate and feed conversion efficiency were reduced at low temperature in juvenile P. olivaceus. The compensatory growth of juvenile P. olivaceus may therefore be attributed to the improvement of feeding rate. Our results suggested that growth depression occurs when juvenile P. olivaceus are exposed to low temperature for more than one week.

  14. Characterization of F-spondin in Japanese flounder (Paralichthys olivaceus) and its role in the nervous system development of teleosts.

    PubMed

    Hu, Hongshuang; Xin, Nian; Liu, Jinxiang; Liu, Mengmeng; Wang, Zhenwei; Wang, Wenji; Zhang, Quanqi; Qi, Jie

    2016-01-10

    F-spondin was originally isolated from the developing embryonic floor plate of vertebrates, secreting numerous kinds of neuron-related molecules. The protein performs a positive function in nervous system development, which is attributed to the high conservation of F-spondin protein, an extracellular matrix (ECM) protein in several species. However, its precise function remains unknown, especially in marine fish. In this study, the F-spondin of Japanese flounder (Paralichthys olivaceus). was cloned, and its expression pattern and structural characteristics were analyzed. The 2421bp-long cDNA ORF of PoF-spondin was obtained and divided into 14 exons spread over 61,496bp of the genomic sequence. Phylogenetic analysis showed that PoF-spondin was actually the ortholog of the human spon1 gene and shared high identities with other teleost spon1a genes. Quantitative RT-PCR analysis showed that PoF-spondin was maternally expressed, and transcripts were present from one-cell stage to hatching stage, peaking at tailbud stage. Tissue distribution analysis indicated that PoF-spondin was detectable mainly in the gonads (especially in the ovary) and the brain. Whole mount in situ hybridization analysis revealed that the PoF-spondin transcription distributed throughout the cleavage of the ball in the early stage and expressed at a high level in the floor plate of the trunk at tailbud and pre-hatching stages. Furthermore, the expression of genes related to nervous system development (spon1b, foxo3b, and foxj1a) was significantly increased after the injection of PoF-spondin into the embryos of wild-type zebrafish. Furthermore, PoF-spondin significantly suppressed the expression of the chordamesoderm marker gene ntl, increased the expression of otx2/krox20, ectoderm mark genes, and left the expression of dorsal mesodermal marker gene gsc unaffected at 50% epiboly stage in zebrafish. In short, our results suggest that PoF-spondin functions in the development of the teleost nervous

  15. Genetically similar VHSV isolates are differentially virulent in olive flounder Paralichthys olivaceus.

    PubMed

    Cho, Mi Young; Lee, Unn Hwa; Moon, Chang Hoon; Bang, Jong Deuk; Jee, Bo Young; Cha, Seung Ju; Kim, Jin Woo; Park, Myoung Ae; Do, Jeong Wan; Park, Jeong Woo

    2012-11-08

    Two viral hemorrhagic septicemia virus (VHSV) isolates, VHSV-KR-CJA and VHSV-KR-YGH, were isolated from viral hemorrhagic septicemia disease outbreaks in flounder farms in South Korea. The VHSV-KR-CJA isolate was isolated from a flounder farm with high mortality (80%), while the VHSV-KR-YGH isolate was isolated from a flounder farm with low mortality (15%), suggesting that these isolates differ in virulence. The virulence of these isolates was evaluated in juvenile flounder via intraperitoneal injection. Consistent with their virulence in the field, mortality data revealed that the VHSV-KR-CJA isolate was highly pathogenic (cumulative mortality of 80%), while the VHSV-KR-YGH isolate was less pathogenic in flounder (cumulative mortality of 20%). To characterize the genotypes of these viruses, the full open reading frames (ORFs) encoding nucleoprotein N, phosphoprotein P, matrix protein M, glycoprotein G, nonstructural viral protein NV, and polymerase L of these viruses were sequenced and analyzed. Sequence analysis revealed that both isolates are genetically very similar (identical amino acid sequences for P, M, NV, and L and >99.7 and 99.8% amino acid sequence identity for N and G, respectively). Phylogenetic analysis indicated that both of these viruses belong to the Genotype IVa group, suggesting that they originated from a common ancestral virus. The low pathogenicity VHSV strain may potentially evolve to become a more pathogenic strain through only a few nucleotide substitutions. Further functional analyses of mutations in VHSV genes are necessary to identify factors that determine VHSV pathogenicity in flounder.

  16. Molecular cloning and expression of PoIR2, a novel gene involved in immune response in Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Li, Chunmei; Wang, Xubo; Wang, Yanan; Liu, Zhipeng; Zhai, Teng; Zhang, Quanqi

    2010-03-01

    A novel immune-related gene was expressed in Japanese flounder ( Paralichthys olivaceus) injected with Vibrio anguillarum. The complete cDNA contained a 169 bp 5’UTR, a 336 bp open reading frame (ORF) encoding 111 amino acids and a 556bp 3’UTR. Six exons and five introns were identified in the PoIR2 gene. Blastp similarity comparison showed its encoding protein had 50% similarity to Danio rerio neuromedin S (NMS), but further alignment indicated they did not have NMS C-terminal conservational signature domain. So it was not defined as an NMS homologue. Protein structure analysis indicated it had a 26aa signal peptide and was a secretory pathway protein. RT-PCR demonstrated that the expression of PoIR2 was quickly induced and drastically increased in liver, kidney, spleen, gills, intestine, heart, and skeletal muscle after infected with V. anguillarum. These results indicated that the PoIR2 might play some important role in Japanese flounder immune response system. This gene was named PoIR2 ( P.olivaceus immune-related gene 2, GenBank accession number: EU224372). The mature PoIR2 peptide was expressed in BL21(DE3) pLysS using pET-32a(+) vector and a great part of the recombinant mature peptide existed as soluble type.

  17. Expression Analysis of Cathepsin F during Embryogenesis and Early Developmental Stage in Olive Flounder (Paralichthys olivaceus)

    PubMed Central

    Lee, Jang-Wook; Lee, Young Mee; Yang, Hyun; Noh, Jae Koo; Kim, Hyun Chul; Park, Choul-Ji; Park, Jong-Won; Hwang, In Joon; Kim, Sung Yeon; Lee, Jeong-Ho

    2013-01-01

    Cathepsins are members of the multigene family of lysosomal cysteine proteinases and have regulated function in several life processes. The potential role of cathepsin F cysteine gene was expected as protease in the yolk processing mechanism during early developmental stage, but expression analysis was unknown after fertilization. The alignment analysis showed that amino acid sequence of cathepsin F from olive flounder liver expressed sequence tag (EST) homologous to cathepsin F of other known cathepsin F sequences with 87-98% identity. In this study, we examined the gene expression analysis of cathepsin F in various tissues at variety age flounder. Tissue distribution of the cathepsin F mRNA has been shown to be ubiquitous and constitutive pattern regardless of age in each group, although derived from cDNA library using liver sample. The mRNA level of cathepsin F more increased as developmental proceed during embryogenesis and early developmental stage, especially increased in the blastula, hatching stage and 3 days post hatching (dph). As a result, it may suggest that the proteolysis of yolk proteins (YPs) has been implicated as a mechanism for nutrient supply during early larval stages in olive flounder. PMID:25949137

  18. Pharmacokinetics, pharmacokinetic-pharmacodynamic relationship, and withdrawal period of amoxicillin sodium in olive flounder (Paralichthys olivaceus).

    PubMed

    Park, Ji-Yong; Awji, Elias Gebru; Suh, Joo-Won; Park, Seung-Chun

    2016-01-01

    1. The pharmacokinetics (PK) and withdrawal period of amoxicillin sodium in olive flounder and its activity against pathogenic bacteria of olive flounder were investigated. 2. Intramuscular administration (12.5 or 125 mg/kg, n = 160) and HPLC analysis of sera were used. 3. Rapid absorption (Tmax 2.6 and 2.2 h), prolonged action (terminal half-life, 15.52 and 10.42 h; MRT, 18.79 and 14.44 h), and dose-proportional exposure (AUC0-∞, 273.69 and 2755.37 h. μg/ml) were observed after 12.5 and 125 mg/kg doses. 4. The withdrawal period of amoxicillin sodium from muscle plus skin of olive flounder (n =40, water temperature, 23 °C) was 12 d (276 degree days). 5. Amoxicillin sodium had small MICs against Streptococcus iniae (0.008-0.06 μg/ml) and Streptococcus parauberis (0.03-1.0 μg/ml), whereas higher concentrations were required to inhibit Edwardsiella tarda isolates (0.06-16 μg/ml). 6. While large AUC0-24 h/MIC90 and Cmax/MIC90 ratios were obtained for S. iniae and S. parauberis, with drug concentrations in serum greater than MICs for the entire dosing interval (T > MIC90 of 100%), the lower dose (12.5 mg/kg) could not achieve target values of the PK-pharmacodynamic (PD) indices for E. tarda isolates, suggesting the need for higher doses to combat pathogenic bacteria with large MICs.

  19. Possible Involvement of Photoperiodic Regulation in Reproductive Endocrine System of Female Olive Flounder Paralichthys olivaceus

    PubMed Central

    Kim, Hyun Chul; Lee, Chi Hoon; Hur, Sung Pyu; Kim, Byeong Hoon; Park, Jun Young; Lee, Young Don

    2015-01-01

    This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis. PMID:25949205

  20. Possible Involvement of Photoperiodic Regulation in Reproductive Endocrine System of Female Olive Flounder Paralichthys olivaceus.

    PubMed

    Kim, Hyun Chul; Lee, Chi Hoon; Hur, Sung Pyu; Kim, Byeong Hoon; Park, Jun Young; Lee, Young Don

    2015-03-01

    This study investigated possible involvement of photoperiodic regulation in reproductive endocrine system of female olive flounder. To investigate the influence on brain-pituitary axis in endocrine system by regulating photoperiod, compared expression level of Kisspeptin and sbGnRH mRNA in brain and FSH-β, LH-β and GH mRNA in pituitary before and after spawning. Photoperiod was treated natural photoperiod and long photoperiod (15L:9D) conditions from Aug. 2013 to Jun. 2014. Continuous long photoperiod treatment from Aug. (post-spawning phase) was inhibited gonadal development of female olive flounder. In natural photoperiod group, the Kiss2 expression level a significant declined in Mar. (spawning period). And also, FSH-β, LH-β and GH mRNA expression levels were increasing at this period. However, in long photoperiod group, hypothalamic Kiss2, FSH-β, LH-β and GH mRNA expression levels did not show any significant fluctuation. These results suggest that expression of hypothalamic Kiss2, GtH and GH in the pituitary would change in response to photoperiod and their possible involvement of photoperiodic regulation in reproductive endocrine system of the BPG axis.

  1. Preparation and Characterization of an Olive Flounder (Paralichthys olivaceus) Skin Gelatin and Polylactic Acid Bilayer Film.

    PubMed

    Lee, Ka-Yeon; Song, Kyung Bin

    2017-03-01

    Olive flounder skin gelatin (OSG) was used as a film base material. A bilayer film of OSG and polylactic acid (PLA) was prepared using solvent casting method to enhance the film properties. Physical properties of the OSG-PLA film were increased compared with the nonaugmented OSG film. In particular, the PLA lamination decreased water vapor permeability from 2.17 to 0.92 × 10(-9) g·m/m(2) ·s·Pa, as well as of the water solubility from 16.62% to 9.27%, in the bilayer film relative to the OSG film. The oxygen permeability of the OSG-PLA bilayer film was held low by the OSG film, compensating for the high oxygen permeability of the PLA layer. Therefore, the OSG-PLA bilayer film with its enhanced physical properties and high water and oxygen barrier properties can be applied as a food packaging material.

  2. Selection of normalization factors for quantitative real time RT-PCR studies in Japanese flounder (Paralichthys olivaceus) and turbot (Scophthalmus maximus) under conditions of viral infection.

    PubMed

    Zhang, Jian; Hu, Yong-hua; Sun, Bo-guang; Xiao, Zhi-zhong; Sun, Li

    2013-04-15

    Disease outbreaks caused by iridoviruses are known to affect farmed flounder (Paralichthys olivaceus) and turbot (Scophthalmus maximus). To facilitate quantitative real time RT-PCR (qRT-PCR) analysis of gene expression in flounder and turbot during viral infection, we in this study examined the potentials of 9 housekeeping genes of flounder and turbot as internal references for qRT-PCR under conditions of experimental infection with megalocytivirus, a member of the Iridoviridae family. The mRNA levels of the 9 housekeeping genes in the brain, gill, heart, intestine, kidney, liver, muscle, and spleen of flounder and turbot were determined by qRT-PCR at 24h and 72h post-viral infection, and the expression stabilities of the genes were determined with geNorm and NormFinder algorithms. The results showed that (i) viral infection induced significant changes in the mRNA levels of the all the examined genes in a manner that was dependent on both tissue type and infection stage; (ii) for a given time point of infection, stability predictions made by the two algorisms were highly consistent for most tissues; (iii) the optimum reference genes differed at different infection time points at least in some tissues; (iv) at both examined time points, no common reference genes were identified across all tissue types. These results indicate that when studying gene expression in flounder and turbot in relation to viral infection, different internal references may have to be used not only for different tissues but also for different infection stages.

  3. Stage and Tissue Specific Expression of Four TCR Subunits in Olive Flounder (Paralichthys olivaceus).

    PubMed

    Lee, Young Mee; Lee, Jeong-Ho; Noh, Jae Koo; Kim, Hyun Chul; Park, Choul-Ji; Park, Jong-Won; Hwang, In Joon; Kim, Sung Yeon

    2013-12-01

    TCR subunits are members of membrane-bound receptors which allow the fast and efficient elimination of the specific fish pathogens have regulated function in adaptive immunity. Sequence structure of TCR subunits have been reported for various teleosts, but the information of each TCR subunit functional characterization through expression analysis in fish was unknown. In this study, we examined the gene expression of TCR subunits in the early developmental stages and observed transcript levels in various tissues from healthy adult olive flounder by RT-PCR. The mRNA expression of alpha subunit was already detected in the previous hatching step. But the transcripts of another TCR subunit were not observed during embryo development and increased after hatching and maintained until metamorphosis at the same level. It was found that all TCR subunits mRNAs are commonly expressed in the immune-related organ such as spleen, kidney and gill, also weak expressed in fin and eye. TCR alpha and beta subunit were expressed in brain, whereas gamma and delta were not expressed same tissue. The sequence alignment analysis shows that there are more than 80% sequence homology between TCR subunits. Because it has a high similarity of amino acid sequence to expect similar in function, but expression analysis show that will have may functional diversity due to different time and place of expression.

  4. Suppression subtractive hybridization coupled with microarray analysis to examine differential expression of genes in Japanese flounder Paralichthys olivaceus leucocytes during Edwardsiella tarda and viral hemorrhagic septicemia virus infection.

    PubMed

    Matsuyama, Tomomasa; Fujiwara, Atushi; Takano, Tomokazu; Nakayasu, Chihaya

    2011-10-01

    Transcriptional changes in the peripheral blood leucocytes (PBL) of Japanese flounder Paralichthys olivaceus challenged by Edwardsiella tarda and viral hemorrhagic septicemia virus (VHSV) were investigated using suppression subtractive hybridization (SSH) coupled with cDNA microarray analysis. First, we constructed an SSH cDNA library using mRNA samples isolated from PBL of P. olivaceus that had been experimentally infected with E. tarda. We then examined the transcriptional changes occurring in the PBL due to E. tarda and VHSV infection using a cDNA microarray produced using clones produced from the SSH library. A total of 565 and 180 cDNA sequences corresponding to mRNA species that are either up- or down-regulated by E. tarda infection were isolated by SSH. While host gene expression responses in response to E. tarda and VHSV infection share several response elements, distinct patterns of gene expression were also observed. Specifically, E. tarda infection enhanced the expression of cell adhesion molecules while VHSV enhanced the expression of interferon and proteasome-related genes. In challenge trials of the two infectious agents, expression profiles of chemokines were also observed to differ. The results indicated that distinguishing between viral and bacterial infection is possible based on the RNA expression profiles of PBL from infected fish.

  5. Characterization of CD3(+) T lymphocytes of Japanese flounder (Paralichthys olivaceus) and its response after immunization with formalin-inactivated Edwardsiella tarda.

    PubMed

    Tang, Xiaoqian; Qin, Yinghui; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2017-04-01

    The CD3 complex is an important cell surface marker of T lymphocytes and essential for T lymphocytes activation in higher vertebrates. In the present work, the CD3ε of Japanese flounder (Paralichthys olivaceus) was recombinantly expressed in E. coli BL21 (DE3) and used as an immunogen to produce mouse anti-rCD3ε polyclonal antibodies, which could specifically recognize a 20 kDa protein in the membrane proteins of peripheral blood lymphocytes (PBL) of Japanese flounder by co-immunoprecipitation assay. Mass spectrometric analysis showed the 20 kDa protein was the native CD3ε of Japanese flounder. Both the flow cytometric analysis and double immunofluorescence assay (DIFA) showed that the CD3(+) T lymphocytes could be identified specifically by the mouse anti-rCD3ε polyclonal antibodies, which didn't cross-react with the sIgM(+) lymphocytes. Immunohistochemistry showed that CD3(+) T lymphocytes could be detected in gill, skin, stomach, intestine, spleen, liver, head-kidney and mid-kidney. Flow cytometric analysis showed the percentages of CD3(+) T lymphocytes in the PBL, spleen lymphocytes (SL) and head-kidney lymphocytes (HKL) of Japanese flounder increased rapidly after immunization with formalin-inactivated Edwardsiella tarda, and reached their peak levels at 5th day with 12.6%, 9.7% and 8.7%, respectively, and then decreased gradually. These results suggested that CD3(+) T lymphocytes play important roles in mucosal and cell-mediated immunity, and the results would deepen our understanding on the roles of teleost T lymphocytes in the immune response.

  6. Montanide IMS 1312 VG adjuvant enhances the efficacy of immersion vaccine of inactivated viral hemorrhagic septicemia virus (VHSV) in olive flounder, Paralichthys olivaceus.

    PubMed

    Hwang, Jee Youn; Kwon, Mun-Gyeong; Kim, Yu Jin; Jung, Sung-Hee; Park, Myoung-Ae; Son, Maeng-Hyun

    2017-01-01

    Vaccination by immersion is suitable for mass vaccination of small size fish. However, no viral vaccine has been developed for immersion applications, because of low efficacy. In this study, we evaluated the efficacy and safety of immersion vaccine against viral hemorrhagic septicemia (VHS) containing Montanide IMS 1312 VG adjuvant in olive flounder (Paralichthys olivaceus). Healthy fish were vaccinated by an immersion method with a heat-inactivated FP-VHS2010-1 strain of VHS virus (VHSV) in combination with Montanide IMS 1312 VG for 5 min at 20 ± 2 °C. The control group was vaccinated with sterile PBS. No toxicity of immersion vaccine with Montanide IMS 1312 VG adjuvant was observed by hematological and histopathological analysis. Immersion vaccine with adjuvant enhanced gene expression of immune-associated genes, i.e., genes encoding interleukin (IL)-1β, IL-6, IL-8, and Toll-like receptor (TLR) 3. Relative percent survival (RPS) of fish was measured on weeks 4 and 8 post vaccination. In fish vaccinated with adjuvant, RPS was significantly higher than that of fish vaccinated without adjuvant. The results of the present study provide evidence that the VHSV immersion vaccine with Montanide IMS 1312 VG induces protective immunity in olive flounder against VHS.

  7. Changes in microRNAs expression profile of olive flounder (Paralichthys olivaceus) in response to viral hemorrhagic septicemia virus (VHSV) infection.

    PubMed

    Najib, Abdellaoui; Kim, Min Sun; Choi, Seung Hyuk; Kang, Yue Jai; Kim, Ki Hong

    2016-04-01

    To know the effect of viral hemorrhagic septicemia virus (VHSV) infection on the cellular microRNA expression profile in olive flounder (Paralichthys olivaceus), fish were infected with VHSV, and cellular microRNAs expression was analyzed at 0 (control), 6, 12, 24, 48 and 72 h post-infection (h.p.i.) by the high-throughput sequencing. A total of 372 mature miRNAs were identified, and, among them, 63 miRNAs were differentially expressed during VHSV infection. The differentially expressed microRNAs number was greatly increased from 24 h.p.i. compared to the number at 6 and 12 h.p.i., suggesting that the alteration of microRNAs expression by VHSV infection may be related to the progression of VHSV disease. The target prediction analysis, the GO enrichment analysis, and the KEGG pathway analysis of the predicted target genes showed that various biological pathways could be affected by VHSV infection through the down-regulation or up-regulation of host miRNAs. The present results provide a basic information on the microRNAs related to VHSV infection in olive flounder. Considering broad effects of microRNAs on various biological pathways, data in this study can be used to interpret the mechanism of VHSV pathogenesis, which, vice versa, can be used to develop control measures against VHSV.

  8. Detection of Kudoa septempunctata 18S ribosomal DNA in patient fecal samples from novel food-borne outbreaks caused by consumption of raw olive flounder (Paralichthys olivaceus).

    PubMed

    Harada, Tetsuya; Kawai, Takao; Jinnai, Michio; Ohnishi, Takahiro; Sugita-Konishi, Yoshiko; Kumeda, Yuko

    2012-09-01

    Kudoa septempunctata is a newly identified myxosporean parasite of olive flounder (Paralichthys olivaceus) and a suspected causative agent of several food-borne gastroenteritis outbreaks in Japan. Here, we report the detection of K. septempunctata 18S ribosomal DNA in fecal samples of outbreak patients using an efficient method based on real-time PCR. We first performed a spiking experiment to assess whether our previously developed real-time PCR assay was applicable to detect K. septempunctata in feces. Simultaneously, we compared the relative extraction efficacy of K. septempunctata DNA using three commercial kits. Finally, our detection method was validated by testing 45 clinical samples obtained from 13 food-borne outbreaks associated with the consumption of raw flounder and 41 fecal samples from diarrhea patients epidemiologically unrelated to the ingestion of raw fish. We found that the FastDNA Spin Kit for Soil (MP Biomedicals) was the most efficient method for extracting K. septempunctata DNA from fecal samples. Using this kit, the detection limit of our real-time PCR assay was 1.6 × 10(1) spores per g of feces, and positive results were obtained for 21 fecal and 2 vomitus samples obtained from the food-borne outbreaks. To our knowledge, this is the first report to describe the detection of K. septempunctata DNA in patient fecal samples. We anticipate that our detection method will be useful for confirming food-borne diseases caused by K. septempunctata in laboratory investigations.

  9. Effects of NV gene knock-out recombinant viral hemorrhagic septicemia virus (VHSV) on Mx gene expression in Epithelioma papulosum cyprini (EPC) cells and olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Min Sun; Kim, Ki Hong

    2012-03-01

    To determine whether the NV gene of viral hemorrhagic septicemia virus (VHSV) is related to the type I interferon response of hosts, expression of Mx gene in Epithelioma papulosum cyprini (EPC) cells and in olive flounder (Paralichthys olivaceus) in response to infection with either wild-type VHSV or recombinant VHSVs (rVHSV-ΔNV-EGFP and rVHSV-wild) was investigated. A reporter vector was constructed for measuring Mx gene expression using olive flounder Mx promoter, in which the reporter Metridia luciferase was designed to be excreted to culture medium to facilitate measurement. The highest increase of luciferase activity was detected from supernatant of cells infected with rVHSV-ΔNV-EGFP. In contrast cells infected with wild-type VHSV showed a slight increase of the luciferase activity. Interestingly, cells infected with rVHSV-wild that has artificially changed nucleotides just before and after the NV gene ORF, also showed highly increased luciferase activity, but the increased amplitude was lower than that by rVHSV-ΔNV-EGFP. These results strongly suggest that the NV protein of VHSV plays an important role in suppressing interferon response in host cells, which provides a condition for the viruses to efficiently proliferate in host cells. In an in vivo experiment, the Mx gene expression in olive flounder challenged with the rVHSV-ΔNV-EGFP was clearly higher than fish challenged with rVHSV-wild or wild-type VHSV, suggesting that lacking of the NV gene in the genome of rVHSV-ΔNV-EGFP brought to strong interferon response that subsequently inhibit viral replication in fish.

  10. Expression of insulin-like growth factor I receptors at mRNA and protein levels during metamorphosis of Japanese flounder (Paralichthys olivaceus).

    PubMed

    Zhang, Junling; Shi, Zhiyi; Cheng, Qi; Chen, Xiaowu

    2011-08-01

    Insulin-like growth factor I (IGF-I) is an important regulator of fish growth and development, and its biological actions are initiated by binding to IGF-I receptor (IGF-IR). Our previous study has revealed that IGF-I could play an important role during metamorphosis of Japanese flounder, Paralichthys olivaceus. The analysis of IGF-IR expression thus helps further elucidate the IGF-I regulation of metamorphic processes. In this study, the spatial-temporal expression of two distinct IGF-IR mRNAs was investigated by real-time RT-PCR. The spatial distribution of two IGF-IR mRNAs in adult tissues is largely overlapped, but they exhibit distinct temporal expression patterns during larval development. A remarkable decrease in IGF-IR-2 mRNA was detected during metamorphosis. In contrast, a significant increase in IGF-IR-1 mRNA was determined from pre-metamorphosis to metamorphic completion. These indicate that they may play different function roles during the flounder metamorphosis. The levels and localization of IGF-IR proteins during larval development were further studied by Western blotting and immunohistochemistry. Immunoreactive IGF-IRs were detected throughout larval development, and the IGF-IR proteins displayed a relatively abundant expression during metamorphosis. Moreover, the IGF-IR proteins appeared in key tissues, such as thickened skin beneath the migrating eye, developing intestine, gills and kidney during metamorphosis. These results further suggest that the IGF-I system may be involved in metamorphic development of Japanese flounder.

  11. Development of a reverse transcription loop-mediated isothermal amplification assay for detecting nervous necrosis virus in olive flounder Paralichthys olivaceus.

    PubMed

    Suebsing, Rungkarn; Oh, Myung-Joo; Kim, Jeong-Ho

    2012-07-01

    In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the rapid, sensitive, and inexpensive detection of nervous necrosis virus (NNV) in olive flounder, Paralichthys olivaceus, in Korea. A set of six specific primers was designed to target the RNA 2 gene encoding the coat protein of Korean NNV strains. The RT-LAMP reaction successfully detected NNV after 30 min at 65 degrees C. When the sensitivities among RT-LAMP, RT-PCR, and nested RTPCR were compared, the RT-LAMP was shown to be able to detect the RNA template at 2.58 × 10(-2) TCID50/ml, whereas the RT-PCR and nested RT-PCR were only able to detect the RNA template at 2.58 × 10(2) TCID50/ml and 2.58 TCID50/ml, respectively. Thus, the sensitivity of the RT-LAMP assay was higher than those of the RT-PCR assays. In the specificity test of the RT-LAMP, 2 genotypes of NNVs (SJNNV and RGNNV) were positive; however, no other fish viruses were positive with the primers, indicating that the RT-LAMP assay is only specific to NNV. A total of 102 olive flounder were collected from hatcheries between 2009 and 2011. The occurrence of NNV in olive flounder was determined to be 53.9% (55/ 102) by the RT-LAMP. On the other hand, the prevalence based on the nested RT-PCR and RT-PCR results was 33.8% (34/102) and 20.6% (21/102), respectively. This result indicates that the RT-LAMP assay developed in this study is suitable for early field diagnosis of NNV with high sensitivity.

  12. Cloning and stage-specific expression of CK-M1 gene during metamorphosis of Japanese flounder, Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Chen, Yanjie; Zhang, Quanqi; Qi, Jie; Wang, Zhigang; Wang, Xubo; Sun, Yeying; Zhong, Qiwang; Li, Shuo; Li, Chunmei

    2010-05-01

    The symmetrical body of flatfish larvae changes dramatically into an asymmetrical form after metamorphosis. The molecular mechanisms responsible for this change are poorly understood. As an initial step to clarify these mechanisms, we used representational difference analysis of cDNA for the identification of genes active during metamorphosis in the Japanese flounder, Paralichthys olicaceus. One of the up-regulated genes was identified as creatine kinase muscle type 1 (CK-M1). Sequence analysis of CK-M1 revealed that it spanned 1 708 bp and encoded a protein of 382 amino acids. The overall amino acid sequence of the CK-M1 was highly conserved with those of other organisms. CK-M1 was expressed in adult fish tissues, including skeletal muscle, intestine and gill. Whole mount in-situ hybridization showed that the enhanced expression of CK-M1 expanded from the head to the whole body of larvae as metamorphosis progressed. Quantitative analysis revealed stage-specific high expression of CK-M1 during metamorphosis. The expression level of CK-M1 increased initially and peaked at metamorphosis, decreased afterward, and finally returned to the pre-metamorphosis level. This stage-specific expression pattern suggested strongly that CK-M1 was related to metamorphosis in the Japanese flounder. Its specific role in metamorphosis requires further study.

  13. Generation of G gene-deleted viral hemorrhagic septicemia virus (VHSV) and evaluation of its vaccine potential in olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Min Sun; Park, Ji Sun; Kim, Ki Hong

    2015-08-01

    Generation of recombinant viruses lacking an essential gene for the production of infective viral particles would be a way to produce safety-enhanced live viral vaccines. The rhabdoviral envelope-spiked glycoprotein (G) plays critical roles in the attachment of viruses on the cell surface receptor and in the transfer of endocytosed viruses to the cytoplasm by fusion to the endosomal membrane. In the present study, we produced a G gene-lacking recombinant viral hemorrhagic septicemia virus (rVHSV-ΔG) that has no ability to form plaques in the cells without a trans-supply of the G protein, which suggests that rVHSV-ΔG is a single cycle virus and progenies of rVHSV-ΔG are not infectious. One of the major advantages of attenuated vaccines is the maintenance of replication ability in the host, which enforces the adaptive immune responses. However, in spite of lacking an ability to produce infective viral particles, immunization with the present rVHSV-ΔG induced significantly higher serum neutralization titers and survival rates against virulent VHSV challenge in olive flounder (Paralichthys olivaceus) fingerlings, indicating that the present rVHSV-ΔG has a high potential as a prophylactic vaccine.

  14. Molecular characterization of heat shock protein 70 (HSP 70) promoter in Japanese flounder (Paralichthys olivaceus), and the association of Pohsp70 SNPs with heat-resistant trait.

    PubMed

    Qi, Jie; Liu, Xudong; Liu, Jinxiang; Yu, Haiyang; Wang, Wenji; Wang, Zhigang; Zhang, Quanqi

    2014-08-01

    Ambient temperature is one of the major abiotic environmental factors determining the main parameters of fish vital activity. HSP70 plays an essential role in heat response. In this investigation, the promoter and structure of Paralichthys olivaceus hsp70 (Pohsp70) gene was cloned and predicted. 2558 bp upstream regulatory region of Pohsp70 was annotated with four potential promoter elements and four putative binding sites of transcription factors heat shock elements (HSE, nGAAn) in the upstream of the transcription start site. In addition, one intron with 454 bp in the 5'-noncoding region was found. Quantitative Real Time PCR analysis indicated that the transcript level of Pohsp70 was raised markedly after 1 h by heat shocked. Furthermore, 25 SNPs were identified in Pohsp70 by resequencing, seven of which was associated with heat resistance. In addition, two of the seven SNPs, namely SNP14 and SNP16, were observed in strong linkage disequilibrium. The haplotype with association analysis showed TAGGAG haplotype was more represented in heat susceptible group while (DEL/T) GAATA haplotype was more frequent in heat resistant group. The heat resistant SNPs and haplotype could be candidate markers potentially serving for selective breeding programs of Japanese flounder aimed at improving anti-stress and production.

  15. Inactivated vaccine against viral hemorrhagic septicemia (VHS) emulsified with squalene and aluminum hydroxide adjuvant provides long term protection in olive flounder (Paralichthys olivaceus).

    PubMed

    Vinay, Tharabenahalli-Nagaraju; Kim, Ye-Ji; Jung, Myung-Hwa; Kim, Wi-Sik; Kim, Do-Hyung; Jung, Sung-Ju

    2013-09-23

    Viral hemorrhagic septicemia (VHS) in olive flounder (Paralichthys olivaceus) remains an unsolved health problem in Korean aquaculture. Vaccination plays a significant role in modern aquaculture, and the duration of protection provided is of vital importance. Here, we have demonstrated the efficacy, duration of protection and safety of an inactivated vaccine emulsified with squalene (5%) and aluminum hydroxide (0.5%). The inactivated VHS vaccine provided a moderate protection of 37% and 47% relative percent survival (RPS) at 4 and 10 weeks post vaccination (wpv). Addition of squalene and aluminum hydroxide into inactivated VHS vaccine clearly enhanced the level of protection showing 58% and 83% RPS at 4 and 10 wpv, respectively, indicating the need for adjuvants to enhance the efficacy. The vaccinated fish showed significant protection at 3, 6, 12, 18, 24, and 40 wpv (except week 57) than non-vaccinated fish to an intraperitoneal challenge of 10(7.1)TCID₅₀/fish at 15 °C, with RPS of 60%, 64%, 71%, 55%, 52% and 50% (45% at 57 week), respectively, covering the duration of natural outbreak. Fish challenged at 18 wpv at 6 °C showed 56% RPS and protection at a low temperature. The antibody titer was high at 3 wpv with an OD of 1.08 ± 0.13, but decreased gradually and was undetectable by 24 wpv. The vaccine formulation was safe without injection site reactions, adhesions, or pigmentation observed at 6, 12, 18, or 24 wpv. Inflammatory reactions were observed in the spleen intestine at 6 and 12 wpv but were similar as control by 24 wpv. These results confirm that this vaccine is efficient and safe for olive flounder and could offer an appropriate strategy to prevent VHS without causing side effects.

  16. Effects of different light wavelengths from LEDs on oxidative stress and apoptosis in olive flounder (Paralichthys olivaceus) at high water temperatures.

    PubMed

    Kim, Bong-Seok; Jung, Seo Jin; Choi, Young Jae; Kim, Na Na; Choi, Cheol Young; Kim, Jae-Woo

    2016-08-01

    We investigated how different light spectra affect thermal stress in olive flounder (Paralichthys olivaceus), using light emitting diodes (LEDs; blue, 450 nm; green, 530 nm; red, 630 nm) at two intensities (0.3 and 0.5 W/m(2)) at relatively high water temperatures (25 and 30 °C, compared to a control condition of 20 °C). We measured the expression and activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), and the levels of plasma hydrogen peroxide (H2O2) and lipid peroxidation (LPO). Furthermore, the levels and mRNA expression of caspase-3 were measured, and terminal transferase dUTP nick end labeling (TUNEL) assays of liver and comet assays were performed. The expression and activity of antioxidant enzymes, as well as plasma H2O2 and LPO levels were significantly higher after exposure to high temperatures, and significantly lower after exposure to green and blue light. Caspase-3 levels and mRNA expression showed a similar pattern. The TUNEL assay showed that apoptosis markedly increased at higher water temperatures, compared with the 20 °C control. In contrast, green light irradiation decreased apoptosis rate. Furthermore, the comet assays showed that nuclear DNA damage was caused by thermal stress, and that green light irradiation played a role in partially preventing this damage. Overall, these results suggest that light with green and blue wavelengths can reduce both high temperature-induced oxidative stress and apoptosis, and that particularly green light is efficient for this. Therefore, green light can play a role in protecting in olive flounder from thermal stress damage.

  17. Dietary Hizikia fusiformis glycoprotein-induced IGF-I and IGFBP-3 associated to somatic growth, polyunsaturated fatty acid metabolism, and immunity in juvenile olive flounder Paralichthys olivaceus.

    PubMed

    Choi, Youn Hee; Kim, Kang-Woong; Han, Hyon-Sob; Nam, Taek Jeong; Lee, Bong-Joo

    2014-01-01

    This study was aimed to examine the effect of dietary glycoprotein extracted from the sea mustard Hizikia fusiformis (Phaeophyceae: Sargassaceae) as a dietary supplement on growth performance in association with somatotropin level, proximate compositions, and immunity in juvenile olive flounder Paralichthys olivaceus. Water-ethanol extracted glycoprotein from H. fusiformis was supplemented to three fishmeal-based diets at the concentration of 0, 5, and 10gkg(-1) diet (designated as H0, H5, and H10, respectively). After a 12week-long feeding trial, growth performance and biochemical responses were analyzed including proximate composition, and whole body amino acids and fatty acids. We also measured plasma insulin like growth factor (IGF), IGF-binding protein (IGFBP) and interleukin (IL). The fish fed H5 showed the greatest weight gain among the dietary treatments. In parallel with the growth, the fish fed the diets containing H. fusiformis glycoprotein showed an increased plasma IGF-I activity and increased expression of 43-kDa IGFBP-3 compared to that in the control, whereas an opposite trend was observed for 34-kDa IGFBP-1. Although no differences were found in the level of whole body linoleic acid (C18:2n-6) and linolenic acid (C18:3n-3) among treatments, increases in arachidonic acid (ARA, C20:4n-6), eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3) were observed in fish fed H5 compared to control. IL-2 and -6 levels increased significantly in fish fed H10 compared to those in the control indicating increased immunity. These results suggest that supplementation of H. fusiformis glycoprotein in fish diet may be beneficial for fish growth and immunity in juvenile olive flounder.

  18. Molecular Characterization and Expression Analysis of ATP-Gated P2X7 Receptor Involved in Japanese Flounder (Paralichthys olivaceus) Innate Immune Response

    PubMed Central

    Li, Shuo; Li, Xuejing; Coddou, Claudio; Geng, Xuyun; Wei, Junli; Sun, Jinsheng

    2014-01-01

    ATP-gated P2X7 receptor (P2RX7) channel is a key component for purinergic signaling and plays important roles in the innate immune response in mammals. However, the expression, molecular properties and immune significances of P2RX7 in lower vertebrates are still very limited. Here we identified and characterized a novel bony fish P2RX7 homologue cDNA, termed poP2RX7, in Japanese flounder (Paralichthys olivaceus). PoP2RX7 protein shares about 60–88% sequence similarity and 45–78% sequence identity with known vertebrate P2RX7 proteins. Phylogenetic analysis placed poP2RX7 and other P2RX7 proteins within their own cluster apart from other P2RX members. While the functional poP2RX7 channel shares structural features in common with known P2RX7 homologs, electrophysiological studies revealed that BzATP, the more potent agonist for known mammalian and fish P2RX7s, shows similar potency to ATP in poP2RX7 activation. poP2RX7 mRNA constitutively expressed in all examined tissues from unstimulated healthy Japanese flounder with dominant expression in hepatopancreas and the lowest expression in head kidney, trunk kidney, spleen and gill. poP2RX7 mRNA expression, however, was significantly induced in Japanese flounder head kidney primary cells by Poly(I:C) and bacterial endotoxin LPS stimulations. In vivo experiments further revealed that poP2RX7 gene expression was substantially up-regulated by immune challenge with infectious bacteria Edwardsiella tarda and Vibrio anguillarum. Moreover, activation of poP2RX7 results in an increased gene expression of multifunctional cytokines IL-1β and IL-6 in the head kidney primary cells. Collectively, we identified and characterized a novel fish P2RX7 homolog which is engaged in Japanese flounder innate immune response probably through modulation of pro-inflammatory cytokines expression. PMID:24796752

  19. Histological change and heat shock protein 70 expression in different tissues of Japanese flounder Paralichthys olivaceus in response to elevated temperature

    NASA Astrophysics Data System (ADS)

    Liu, Yifan; Ma, Daoyuan; Xiao, Zhizhong; Xu, Shihong; Wang, Yanfeng; Wang, Yufu; Xiao, Yongshuang; Song, Zongcheng; Teng, Zhaojun; Liu, Qinghua; Li, Jun

    2015-01-01

    High temperature influences the homeostasis of fish. We investigated the effects of elevated temperature on tissues of Japanese flounder ( Paralichthys olivaceus) by analyzing the histology and heat shock protein 70 ( hsp70) expression of fish reared in warm conditions. In this study, temperature was increased at 1±0.5°C/day starting at 24±0.5°C, and was kept at that temperature for 5 days before the next rise. After raising temperature at the rate up to 32±0.5°C, tissue samples from midgut, spleen, stomach, liver, muscle, gill, heart, trunk kidney and brain were collected for histological analysis and mRNA assay. Almost all the tissues showed changes in morphological structure and hsp70 level at 32±0.5°C. Histological assessment of the tissues indicated that the gill had the most serious damage, including highly severe epithelial lifting and edema, curved tips and hyperemia at the ending of the lamellars, desquamation and necrosis. The next most severe damage was found in liver and kidney. The hsp70 levels in all the tissues first increased and then decreased. The gut, stomach, muscle, heart, and brain had the highest expressions in 6 h, whereas the spleen, liver, gill and kidney had the highest expressions in 2 h. Therefore, tissues with the most significant lesions (especially gill and liver) responded much earlier (2 h) in hsp70 expression than other tissues, and these tissues demonstrated the most marked histological disruption and elevated mRNA levels, making them ideal candidates for further studies on the thermal physiology of this species.

  20. Temperature-dependent viral replication and antiviral apoptotic response in viral haemorrhagic septicaemia virus (VHSV)-infected olive flounder (Paralichthys olivaceus).

    PubMed

    Avunje, Satheesha; Kim, Wi-Sik; Oh, Myung-Joo; Choi, Ilsu; Jung, Sung-Ju

    2012-06-01

    The olive flounder (Paralichthys olivaceus) shows a high rate of mortality to viral haemorrhagic septicaemia virus (VHSV) in the winter and spring but has zero mortality over 20 °C. In this experiment, we studied the effect of rearing temperature on viral replication, viral transcription and antiviral apoptotic immune response in VHSV-infected olive flounder by real-time polymerase chain reaction. Olive flounder were given intra-peritoneal injections of VHSV (10(7.8) TCID(50)/ml) and were reared at 15 °C or 20 °C. Five fish were randomly sampled for head kidney at 3, 6 and 12 h post-infection (hpi) and 1, 2, 4 and 7 days post-infection (dpi). Total RNA extracted from the tissue was reverse transcribed and used as template for real-time PCR. In the 15 °C group, the number of viral gRNA copies peaked after 2 dpi and remained high through 7 dpi, while in the 20 °C group, the copy number was at the highest at 1 dpi but drastically declined at later stages. Viral mRNA levels in the 15 °C group gradually increased starting at 3 hpi to reach their maximum value at 12 hpi and remained high until 2 dpi, whereas the other group showed much lower copy numbers that were undetectably low at 4 and 7 dpi. Type II IFN expression increased as the viral copies increased and the 20 °C group showed quicker and stronger expression than the 15 °C group. The MHC class I and CD8 expression was high in both the groups at early stage of infection (3-6 hpi) but at later stages (2-7 dpi) in 15 °C group expression reduced below control levels, while they expressed higher to control in 20 °C group. The expression of granzyme in 15 °C fish showed a single peak at 2 dpi, but was consistently expressing in 20 °C fish. Individuals expressed very high levels of perforin expressed very high levels of caspase 3. In 15 °C fish, TNFα, FasL and p53 expressed significantly higher than 20 °C only at initial stages of infection (3-6 hpi). Caspase 3 expression found to be low in 15 °C fish

  1. Characterization of flounder ( Paralichthys olivaceus) FoxD5 and its function in regulating myogenic regulatory factor

    NASA Astrophysics Data System (ADS)

    Tan, Xungang; Zhang, Yuqing; Sun, Wei; Zhang, Peijun; Xu, Yongli

    2012-03-01

    As one member of winged helix domain transcription factors, FoxD5 was reported to be a trunk organizer. Recent study showed that zebrafish foxd5 is expressed in the somites. To further understand the function of FoxD5 in fish muscle development, the FoxD5 gene was isolated from flounder. Its expression pattern was analyzed by in situ hybridization, while its function in regulating myogenic regulatory factor, MyoD, was analyzed by ectopic expression. It showed that flounder FoxD5 was firstly expressed in the tailbud, adaxial cells, and neural plate of the head. In flounder embryo, FoxD5 is expressed not only in forebrain but also in somite cells that will form muscle in the future. When flounder FoxD5 was over-expressed in zebrafish by microinjection, the expression of zebrafish MyoD in the somites was reduced, suggesting that FoxD5 is involved in myogenesis by regulating the expression of MyoD.

  2. Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis.

    PubMed

    Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

    2015-04-01

    High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1-8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species.

  3. Up-regulation of hepatic receptor for growth hormone in the flounder ( Paralichthys olivaceus) after oral administration with exogenous GH

    NASA Astrophysics Data System (ADS)

    Liu, Zong-Zhu; Wang, Jin-Bao; Xu, Yong-Li; Wang, Yong; Zhang, Pei-Jun

    2001-06-01

    The iodination efficiency of salmon GH(sGH) was 38.82%, using a modification of the chloramine-T method. The specific activity of the125I-sGH was about 40 μCi/μg protein. The results of binding assay showed a single class of high affinity and low-capacity binding site in flounder liver. Long-term administration with exogenous GH can induce the up-regulation of hepatic GH receptor in total binding capacity though there was no significant difference in capacity of free binding sites of livers from control and experimental fish, this result also indicated that the liver from experimental fish, compared to that from control fish, had more occupied binding sites.

  4. Lactococcus lactis BFE920 activates the innate immune system of olive flounder (Paralichthys olivaceus), resulting in protection against Streptococcus iniae infection and enhancing feed efficiency and weight gain in large-scale field studies.

    PubMed

    Kim, Daniel; Beck, Bo Ram; Heo, Saet-Byeol; Kim, Jungjoon; Kim, Hyun Duk; Lee, Sun-Min; Kim, Youngchan; Oh, So Young; Lee, Kyungro; Do, HyungKi; Lee, KwanHee; Holzapfel, Wilhelm H; Song, Seong Kyu

    2013-11-01

    The protective effect of a food-grade lactic acid bacterium Lactococcus lactis BFE920 against disease of olive flounder (Paralichthys olivaceus) cultivated on a large scale was studied. Initially, antimicrobial activity of L. lactis against several fish pathogens was evaluated in vitro; the probiotic showed strong antibacterial activity against Streptococcus iniae, Streptococcus parauberis and Enterococcus viikkiensis, and moderate activity against Lactococcus garviae. When olive flounders were fed for two weeks with experimental diets containing varying concentrations of L. lactis (1 × 10(6), 5 × 10(6), 2.5 × 10(7) and 1.25 × 10(8) CFU/g feed), all the experimental feed groups showed 68-77% survival upon challenge with S. iniae. A field-scale feeding trial with L. lactis dietary supplement was conducted in a local fish farm (n = 12,000) for three months, and disease resistance, innate immune parameters and growth performance were evaluated. The average weight gain and feed efficiency were increased up to 6.8% and 8.5%, respectively. At the end of the feeding trial, the olive flounders were challenged with S. iniae. The L. lactis-fed group was protected from S. iniae challenge with a 66% survival rate. This disease protection is due to the flounder's innate immunity activated by the L. lactis administration: increased lysosomal activities and production of IL-12 and IFN-γ. These data clearly indicated that L. lactis BFE920 may be developed as a functional feed additive for protection against diseases, and for enhancement of feed efficiency and weight gain in olive flounder farming.

  5. Evolutionary Conservation of pou5f3 Genomic Organization and Its Dynamic Distribution during Embryogenesis and in Adult Gonads in Japanese Flounder Paralichthys olivaceus

    PubMed Central

    Gao, Jinning; Wang, Xubo; Zhang, Quanqi

    2017-01-01

    Octamer-binding transcription factor 4 (Oct4) is a member of POU (Pit-Oct-Unc) transcription factor family Class V that plays a crucial role in maintaining the pluripotency and self-renewal of stem cells. Though it has been deeply investigated in mammals, its lower vertebrate homologue, especially in the marine fish, is poorly studied. In this study, we isolated the full-length sequence of Paralichthys olivaceus pou5f3 (Popou5f3), and we found that it is homologous to mammalian Oct4. We identified two transcript variants with different lengths of 3′-untranslated regions (UTRs) generated by alternative polyadenylation (APA). Quantitative real-time RT-PCR (qRT-PCR), in situ hybridization (ISH) and immunohistochemistry (IHC) were implemented to characterize the spatial and temporal expression pattern of Popou5f3 during early development and in adult tissues. Our results show that Popou5f3 is maternally inherited, abundantly expressed at the blastula and early gastrula stages, then greatly diminishes at the end of gastrulation. It is hardly detectable from the heart-beating stage onward. We found that Popou5f3 expression is restricted to the adult gonads, and continuously expresses during oogenesis while its dynamics are downregulated during spermatogenesis. Additionally, numerous cis-regulatory elements (CRE) on both sides of the flanking regions show potential roles in regulating the expression of Popou5f3. Taken together, these findings could further our understanding of the functions and evolution of pou5f3 in lower vertebrates, and also provides fundamental information for stem cell tracing and genetic manipulation in Paralichthys olivaceus. PMID:28124980

  6. Screening of eye-position related genes with DD-RT-PCR and RDA in the hybrids between Japanese flounder Paralichthys olivaceus and stone flounder Kareius bicoloratus

    NASA Astrophysics Data System (ADS)

    Chen, Yanjie; Zhang, Quanqi; Qi, Jie; Sun, Yeying; Zhong, Qiwang; Wang, Xubo; Wang, Zhigang; Li, Shuo; Li, Chunmei

    2009-02-01

    Flatfish or flounder moves one eye to change body proportion into vertebral asymmetry during metamorphosis, during which some become sinistral while others dextral. However, the mechanism behinds the eye-position has not been well understood. In this research, hybrids between Japanese flounder(♀) and stone flounder (♂) show mixed eye-location in both dextral type and sinistral type, and thus become good samples for studying the eye-migration. mRNAs from pro-metamorphosis sinistral and dextral hybrids larvae were screened with classical differential display RT-PCR (DD-RT-PCR) and representational difference analysis of cDNA (cDNA-RDA); 30 and 47 putative fragments were isolated, respectively. The cDNA fragments of creatine kinase and trypsinogen 2 precursor genes isolated by cDNA-RDA exhibited eye-position expression patterns during metamorphosis. However, none of the fragments was proved to be related to flatfishes’ eye-position specifically. Therefore, further studies and more sensitive gene isolated methods are needed to solve the problems.

  7. Stability and efficacy of the 3'-UTR A4G-G5A variant of viral hemorrhagic septicemia virus (VHSV) as a live attenuated immersion VHSV vaccine in olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Sung-Hyun; Kim, Meesun; Choi, Go-Eun; Lee, Jeong Ho; Kang, Jung-Ha; Evensen, Øystein; Lee, Woo-Jai

    2016-02-17

    Viral hemorrhagic septicemia virus (VHSV) is the causative agent of viral hemorrhagic septicemia in fish, a disease that affects a number of teleost fish species including olive flounder (Paralichthys olivaceus). In this study, we assessed the safety and efficacy of two recombinant attenuated VHSV strains, termed A4G-G5A and ΔNV, with the purpose to select the most suitable vaccine strain. The virus strains were passaged in two commercially available cell lines, EPC and RTG-2, and the strains were also tested for residual virulence in zebrafish (Danio rerio). The A4G-G5A strain showed an attenuated growth profile in both the EPC and RTG-2 cell lines compared to wild-type (WT) VHSV (JF-09, genotype IVa), whereas the growth profile of ΔNV was comparable to the WT strains in RTG-2 cells in contrast to EPC cells. Moreover, ΔNV had higher residual virulence compared to A4G-G5A and was highly pathogenic to zebrafish. The A4G-G5A strain was chosen as vaccine candidate and tested for efficacy in in vivo fish studies in the target species, olive flounder, using an immersion vaccine scheme. Groups of fish were immunized with 10(2.5), 10(3.5), 10(4.5), and 10(5.5) TCID50/ml of A4G-G5A giving 5-13.3 cumulative percent mortality (CPM) post immunization. Immunization was followed by a challenge experiment using VHSV-WT. The relative percent survival (RPS) in immunized groups ranged from 81.6% to 100%, correlating with vaccination dose. This study demonstrates that while strain A4G-G5A has retained some residual virulence it confers high level of protection in immunized olive flounder.

  8. Study on embryonic development and early growth of triploid and gynogenetic diploid left-eyed flounder, Paralichthys olivaceus (T. et S.)

    NASA Astrophysics Data System (ADS)

    You, Feng; Liu, Jing; Wang, Xin-Cheng; Xu, Yong-Li; Huang, Rui-Dong; Zhang, Pei-Jun

    2001-06-01

    The early effects of chromosomal manipulation of eggs and sperm on the yields of triploid and gynogenetic diploid larvae of Paralichthys olivaceus were investigated Triploidy was achieved by cold shocking fertilized eggs at 0 2°C for 45 minutes duration 5 minutes after, fertilization, and the induced triploidy rates were 31.2% 50% and the relative hatching rates were 53.3% 99%. Gynogenetic diploids were obtained when eggs were inseminated with irradiated sperm and cold shocked at 0 2°C for 45 minutes duration 5 minutes after fertilization. The induced gynogenetic diploid rates and the relative hatching rates were 94% 96% and 48.5% 68.5% respectively. The embryonic development of the triploid experimental group and of the gynogenetic diploid experimental group was delayed at first compared with the control group. But from the gastrula stage, it was not delayed anymore. There were no significant differences in the growth of the triploid experimental group larvae and the control group larvae, and in the growth of the gynogenetic diploid experimental group larvae and the control group larvae according to Student’s t-test (α=0.05). The relationship between the early growth of the triploid experimental group larvae and that of gynogenetic diploid experimental group larvae was also studied.

  9. Comparison of the efficacy of Poly(I:C) immunization with live vaccine and formalin-killed vaccine against viral hemorrhagic septicemia virus (VHSV) in olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Hyoung Jun; Park, Jeong Su; Choi, Min Chul; Kwon, Se Ryun

    2016-01-01

    Viral hemorrhagic septicemia (VHS) in olive flounder, Paralichthys olivaceus, causes significant economic loss for the flounder aquaculture industry in Korea. In this study, the immunogenicity of Poly(I:C) immunization with a live vaccine against the VHS virus (VHSV) was compared with that of a formalin-treated vaccine in the olive flounder. In vaccine trial I, fish pre-injected with Poly(I:C) were highly protected from VHSV infection 2 d later (survival rate: 96%) and the surviving fish (Poly(I:C)-VHSV group) showed a 100% survival rate against VHSV re-challenge. Mortality in fish pre-injected with diethylpyrocarbonate-treated water followed by injection with formalin-treated VHSV was only 2% (1 of 50 fish), whereas survivors (DEPC-FT VHSV group) showed an 80% survival rate. In vaccine trial II, 100% survival was observed in all Poly(I:C) vaccination groups-Poly(I:C)-VHSV 6, Poly(I:C)-VHSV 5, and Poly(I:C)-VHSV 4. In contrast, the survival rates of the groups administered the formalin-treated VHSV at a dose of 10(6), 10(5), and 10(4) TCID50 100 μL(-1) fish(-1) (DEPC-FT VHSV 6, DEPC-FT VHSV 5, and DEPC-FT VHSV 4) were only 8%, 12%, and 12%, respectively. The differences in the survival rates of the formalin-treated vaccine groups in trial I and trial II were attributed to the difference in the formalin-treatment period: the formalin-treated VHSV administered in trial I was not completely inactivated and worked as a live vaccine, which explains the 80% survival rate against VHSV challenge. Specific antibodies against VHSV were detected in sera from all vaccinated survivors, except the DEPC-VHSV 4 group. Furthermore, the specific antibody titers of fish vaccinated with the live and dead VHSV vaccines were similar, but the protective effects of the live and dead vaccines varied considerably. Our findings show that Poly(I:C) immunization with the live vaccine offers better protection than the formalin-treated vaccine against VHS in olive flounder and revealed that

  10. Effect of G gene-deleted recombinant viral hemorrhagic septicemia virus (rVHSV-ΔG) on the replication of wild type VHSV in a fish cell line and in olive flounder (Paralichthys olivaceus).

    PubMed

    Kim, Min Sun; Choi, Seung Hyuk; Kim, Ki Hong

    2016-07-01

    In an earlier study, we generated a replicon viral hemorrhagic septicemia virus (VHSV) particle that was lacking the G gene in the genome (rVHSV-ΔG), and proved the potential of it as a protective vaccine through the immunization of olive flounder (Paralichthys olivaceus) fingerlings. Safety is the most important preconsideration for the development of recombinant live vaccines, and a major concern of propagation-incompetent viral particles would be the possible harmful effect to hosts through the interaction with wild-type viruses. Thus, in the present study, we analyzed the replication of rVHSV-ΔG in the presence of wild-type VHSV and the effect of rVHSV-ΔG on the replication of wild-type VHSV in Epithelioma papulosum cyprini (EPC) cells and in olive flounder fingerlings. The replication of wild-type VHSV in EPC cells was severely suppressed when the MOI of rVHSV-ΔG was 0.1 or 0.01, on the other hand, the titers of rVHSV-ΔG were not increased and stayed in a relatively constant according to time lapse. Furthermore, the replication of other novirhabdoviruses, IHNV and HIRRV, was also inhibited by co-infection with high titers of rVHSV-ΔG. There were no big differences in mortalities between groups infected with wild-type VHSV plus rVHSV-ΔG and groups infected with wild-type VHSV alone, when the challenged wild-type VHSV was more than 10(2) PFU/fish. However, a group of fish infected with 10 PFU/fish of wild-type VHSV plus rVHSV-ΔG showed significantly lower and slowly progressing cumulative mortality than a group of fish infected with 10 PFU/fish of wild-type VHSV alone. This result suggests that rVHSV-ΔG has an ability to attenuate the disease progression caused by wild-type VHSV when co-infected with relatively low titers of wild-type VHSV. These results indicate that the propagation-incompetent rVHSV-ΔG would not worsen but attenuate the progression of a disease caused by wild-type VHSV infection. Therefore, rVHSV-ΔG-based vaccines can provide a

  11. RNA-Seq transcriptome analysis of the olive flounder (Paralichthys olivaceus) kidney response to vaccination with heat-inactivated viral hemorrhagic septicemia virus.

    PubMed

    Hwang, Jee Youn; Kwon, Mun Gyeoung; Jung, Sung-Hee; Park, Myoung Ae; Kim, Dong-Wook; Cho, Wang Sik; Park, Jeong Woo; Son, Maeng-Hyun

    2017-03-01

    Viral hemorrhagic septicemia (VHS) is a highly contagious disease of cultured flounder caused by VHS virus (VHSV). To develop effective VHSV vaccines, it is essential to understand the molecular mechanisms underlying the host's protective response against VHSV. The purpose of this study is to clarify which genes are involved in the protective response of olive flounder after VHSV vaccination. We first injected olive flounder intraperitoneally with 10(7) TCID50 heat-inactivated VHSV vaccine and evaluated the vaccine efficacy at 20 °C. Fish vaccinated with heat-inactivated VHSV were significantly protected compared to non-vaccinated fish, with a relative percentage survival of 83%. To analyze the vaccination-induced changes in the expression profiles of genes, kidneys were collected from control and vaccinated fish at days 1, 3, and 7 after vaccination and global gene expression profiling was carried out by RNA sequencing. The analysis revealed that 15,001 genes were differentially expressed by at least 2-fold between vaccinated fish and non-vaccinated controls. Of these, 58 genes clustered into the acute phase response, Toll-like receptor, interferon-inducible/regulatory proteins, and apoptosis pathways. These data provided insights into the molecular mechanisms underlying the protective immune response of olive flounder against heat-inactivated VHSV vaccine and might aid future studies to develop a highly immunogenic vaccine against VHSV in flounder.

  12. Molecular cloning, expression pattern, and 3D structural prediction of the cold inducible RNA-binding protein (CIRP) in Japanese flounder ( Paralichthys olivaceus)

    NASA Astrophysics Data System (ADS)

    Yang, Xiao; Gao, Jinning; Ma, Liman; Li, Zan; Wang, Wenji; Wang, Zhongkai; Yu, Haiyang; Qi, Jie; Wang, Xubo; Wang, Zhigang; Zhang, Quanqi

    2015-02-01

    Cold-inducible RNA-binding protein (CIRP) is a kind of RNA binding proteins that plays important roles in many physiological processes. The CIRP has been widely studied in mammals and amphibians since it was first cloned from mammals. On the contrary, there are little reports in teleosts. In this study, the Po CIRP gene of the Japanese flounder was cloned and sequenced. The genomic sequence consists of seven exons and six introns. The putative PoCIRP protein of flounder was 198 amino acid residues long containing the RNA recognition motif (RRM). Phylogenetic analysis showed that the flounder PoCIRP is highly conserved with other teleost CIRPs. The 5' flanking sequence was cloned by genome walking and many transcription factor binding sites were identified. There is a CpGs region located in promoter and exon I region and the methylation state is low. Quantitative real-time PCR analysis uncovered that Po CIRP gene was widely expressed in adult tissues with the highest expression level in the ovary. The mRNA of the Po CIRP was maternally deposited and the expression level of the gene was regulated up during the gastrula and neurula stages. In order to gain the information how the protein interacts with mRNA, we performed the modeling of the 3D structure of the flounder PoCIRP. The results showed a cleft existing the surface of the molecular. Taken together, the results indicate that the CIRP is a multifunctional molecular in teleosts and the findings about the structure provide valuable information for understanding the basis of this protein's function.

  13. Effects of Dietary Supplementation of Barodon, an Anionic Alkali Mineral Complex, on Growth Performance, Feed Utilization, Innate Immunity, Goblet Cell and Digestibility in Olive Flounder (Paralichthys olivaceus)

    PubMed Central

    Shin, Chang-Hoon; Cha, Ji-Hoon; Rahimnejad, Samad; Jeong, Joon-Bum; Yoo, Byung-Woo; Lee, Bo-Kyeun; Ahn, Hyung-Jin; Choi, Soo-Il; Choi, Yun-Jeong; Park, Yong-Ho; Kim, Jeong-Dae; Lee, Kyeong-Jun

    2014-01-01

    A 15-wk feeding trial was conducted to examine the supplemental effects of Barodon on growth performance, gastrointestinal histology, feed digestibility and innate immunity in olive founder. A basal commercial diet was used as a control and two other diets were prepared by spraying 0.1% or 0.2% of Barodon. Triplicate groups of fish (BW, 145 g) were fed one of the test diets to apparent satiation twice daily. At the end of the feeding trial, fish growth performance was not significantly affected by dietary treatments; however, feed utilization was significantly improved (linear and quadratic, p<0.05) by Barodon supplementation. Significantly higher (p<0.05) survival rates were obtained in fish fed Barodon containing diets. Hepatosomatic index increased significantly in Barodon treated groups. Also, the use of Barodon resulted in significant increase (linear and quadratic, p<0.05) of intestine length and number of goblet cells. Significantly higher (Quadratic, p<0.05) apparent digestibility coefficient of DM was obtained by supplementation of Barodon. Lysozyme and myeloperoxidase activities increased quadratically and linearly, respectively, in Barodon treated fish. Also, significantly higher (linear and quadratic, p<0.05) superoxide dismutase activity was found in Barodon fed fish. The findings in this study show that inclusion of Barodon in diets for olive flounder improves feed utilization and digestibility, and positively affects digestive tract histology and innate immunity. PMID:25049965

  14. Chromatophore distribution and inferior performance of albino Japanese flounder Paralichthys olivaceus with special reference to different chromatophore expression between albinism and pseudo-albinism.

    PubMed

    Shikano, Takahito; Shimada, Yukinori; Nakamura, Aiko

    2007-05-01

    Albinism with a large variation in body color was found in a hatchery population of Japanese flounder. In addition to albinism, ambicoloration and pseudo-albinism were simultaneously observed in some individuals. Albinos had a remarkably lower number of melanophores on the scales of ocular side than wild-type individuals did, although no significant difference was observed in the numbers of xanthophores and iridophores. The intensity of body color significantly correlated with the number of melanophores among the albinos. No significant differences were observed in the intensity of body color and the number of melanophores between the ocular side and the ambicoloration area. Pseudo-albinism was accompanied by the reductions of melanophores and xanthophores, indicating the different expression patterns of chromatophores between albinism and pseudo-albinism. The combined effects of albinism and pseudo-albinism caused the disappearances of melanophores and xanthophores in the pseudo-albinism area of albinos. In addition to chromatophores, the different characteristics of several phenotypic traits were observed between albinos and wild-type individuals. Growth-related traits of the albinos were inferior to those of the wild-type individuals. Furthermore, the albinos had a larger pseudo-albinism area and a higher vertebral deformed rate than the wild-type individuals did. Individual multilocus heterozygosity and inbreeding coefficient measured by microsatellite loci did not show any indication that the albinos had higher inbreeding coefficient than the wild-type individuals did. This study demonstrated the expression patterns of chromatophores in the body color abnormalities of a flatfish species and the potential pleiotropic effects of an albinism gene on some phenotypic traits.

  15. Identification and characterization of a novel NOD-like receptor family CARD domain containing 3 gene in response to extracellular ATP stimulation and its role in regulating LPS-induced innate immune response in Japanese flounder (Paralichthys olivaceus) head kidney macrophages.

    PubMed

    Li, Shuo; Chen, Xiaoli; Hao, Gaixiang; Geng, Xuyun; Zhan, Wenbin; Sun, Jinsheng

    2016-03-01

    Nucleotide oligomerization domain (NOD)-like receptor (NLR) family with a caspase activation and recruitment domain (CARD) containing 3 (NLRC3) protein is an important cytosolic pattern recognition receptor that negatively regulates innate immune response in mammals. Hitherto, the immunological significance of NLRC3 protein in fish remains largely uncharacterized. Here we identified and characterized a novel NLRC3 gene (named poNLRC3) implicated in regulation of fish innate immunity from Japanese flounder Paralichthys olivaceus. The poNLRC3 protein is a cytoplasmic protein with an undefined N-terminal domain, a NACHT domain, a fish-specific NACHT associated domain, six LRR motifs, and a C-terminal fish-specific PYR/SPYR (B30.2) domain but only shares less than 40% sequence identities with the known Japanese flounder NLRC proteins. poNLRC3 gene is ubiquitously expressed in all tested tissues and is dominantly expressed in the Japanese flounder head kidney macrophages (HKMs). We for the first time showed that poNLRC3 expression was significantly modulated by the stimulation of extracellular ATP, an important danger/damage-associated molecular pattern in activating innate immunity in P. olivaceus. Importantly, we revealed that poNLRC3 plays an important role in positively regulating ATP-induced IL-1beta and IL-6 gene expression, suggesting the involvement of poNLRC3 in extracellular ATP-mediated immune signaling. In addition, we showed that poNLRC3 mRNA expression was up-regulated in response to LPS and Edwardsiella tarda immune challenges. Finally, we showed that down-regulating the endogenous poNLRC3 expression with small interfering RNA significantly reduced LPS-induced proinflammatory cytokine gene expression in the Japanese flounder HKM cells. Altogether, we have identified a novel inducible fish NLR member, poNLRC3, which is involved in extracellular ATP-mediated immune signaling and may positively regulate the LPS-induced innate immune response in the Japanese

  16. Analysis of IL-2-like factor in lymphocyte culture supernatant of olive flounder, Paralichthys oliveaceus

    NASA Astrophysics Data System (ADS)

    Wu, Riqin; Zhang, Peijun; Li, Jun; Xu, Yongli

    2005-03-01

    To study immune mechanism of fish lymphocyte we performed a proliferation assay and ELISA using monoclonal antibody against human IL-2. The result showed that an interleukin-2 (IL-2)-like factor was detected in the supernatant of plant haemoglutinin (PHA)-stimulated lymphocyte culture from peripheral blood, spleen and head kidney of olive flounder, Paralichthys olivaceus. The quantities of IL-2-like factor in the supernatant from different lymphoid tissues were quite different. The IL-2 like factor in the supernatant from cultured head kidney lymphocytes was much higher than those of peripheral blood lymphocytes and spleen lymphocytes ( P<0.01). The IL-2 activity was found in either mouse thymocyte proliferation assay or flounder head kidney lymphocyte proliferation assay and shown to have obvious enhancing effect on proliferation of the above two types of cell. The recombinant human IL-2, (rhIL-2) was able to stimulate flounder thymocyte proliferation and used to detect the IL-2 receptor (IL-2R) on the surface of flounder lymphocyte. The cross-reaction between the lymphocytes of flounder peripheral blood and CD25(IL-2R) was detected with flow cytometry and shown that the percentage of CD25-positive cell in peripheral blood was 7.74±0.67%.

  17. Steroid sex hormone dynamics during estradiol-17β induced gonadal differentiation in Paralichthys olivaceus (Teleostei)

    NASA Astrophysics Data System (ADS)

    Sun, Peng; You, Feng; Liu, Mengxia; Wu, Zhihao; Wen, Aiyun; Li, Jun; Xu, Yongli; Zhang, Peijun

    2010-03-01

    Steroid sex hormones, such as estradiol-17β (E2) and testosterone (T), are important regulators of sex change in fish. In this study, we examined the effects of E2 treatment on the dynamics of E2 and T during gonadal differentiation in the olive flounder Paralichthys olivaceus using histology and radioimmunoassay (RIA). Flounder larvae were divided into five groups (G0-G4), and fed with 0 (control), 0.2, 2, 20 and 100 mg E2/kg feed from 35 to 110 day post hatching (dph). Fish growth in the G1 and G2 groups was not significantly different from that of the control group ( P>0.05), while fish in the G3 and G4 groups were less active and showed growth depression and high mortality. The gonads of fish in the G3 and G4 groups were smaller and surrounded by hyperplastic connective tissue. The frequency of females in the G0-G4 groups was 54.5%, 75.0%, 100%, 100% and 93.3%, respectively. The RIA analyses of E2 and T showed that T levels decreased during gonadal differentiation, and increased slightly at the onset of ovarian differentiation, while E2 levels increased gradually and peaked at the onset of ovarian differentiation in the control group. In the E2-treated groups, T levels decreased before the onset of ovarian differentiation. E2 levels were high on the 48 dph, but declined to a lower level on the 54 dph, and then increased gradually during gonadal differentiation. And a sharp increase of E2 levels were observed in all E2-treated groups at the onset of ovarian differentiation. The data suggest that T and E2 play important roles during gonadal differentiation, and an E2 dose of 2 mg/kg feed could induce sex reversal in P. olivaceus.

  18. Structural studies of fertilization-associated carbohydrate-rich glycoproteins (hyosophorin) isolated from the fertilized and unfertilized eggs of flounder, Paralichthys olivaceus. Presence of a novel penta-antennary N-linked glycan chain in the tandem repeating glycopeptide unit of hyosophorin.

    PubMed

    Seko, A; Kitajima, K; Iwasaki, M; Inoue, S; Inoue, Y

    1989-09-25

    New glycoproteins of 100-120 kDa were isolated from the unfertilized eggs of flounder, Paralichthys olivaceus. Compositionally indistinguishable glycopeptides of 6 kDa were also purified from the activated or fertilized eggs. These high and low molecular mass glycoproteins are characterized by high (about 85%) carbohydrate content. Although some heterogeneities exist in the amino acid sequences, the 6-kDa glycopeptides (decapeptides with single large N-linked glycan chains), isolated from the fertilized eggs are the repeating units of the high molecular mass glycoproteins. As judged from several distinctive features the 100-120-kDa glycoproteins are apparently major components of cortical alveoli of flounder eggs and are regarded as members of glycoproteins we have defined under the name of "hyosophorin" (Kitajima, K., Inoue, S., and Inoue, Y. (1989) Dev. Biol. 132, 544-553). Composition analysis, Smith degradation, hydrazinolysis-nitrous acid deamination, permethylation analysis, and 400-MHz 1H NMR spectroscopy provided evidence for the structure of a novel penta-antennary glycan chain attached to the repeating unit (decapeptide) of the protein core. The structure thus determined is: (Formula: see text). The presence of a unique class of carbohydrate-rich glycoproteins (H-hyosophorin) in the unfertilized eggs, their conversion to the repeating unit (L-hyosophorin) at fertilization, and the finding of a free glycan chain that was formed by scission between the GlcNAc and Asn residues of L-hyosophorin, in the fertilized eggs including embryos of 4-11-h postinsemination, support the view that these molecules may be important in fertilization and subsequent development.

  19. VITELLOGENIN-INDUCED PATHOLOGY IN MALE SUMMER FLOUNDER (PARALICHTHYS DENTATUS)

    EPA Science Inventory

    Male summer flounder (Paralichthys dentatus) were given two injections (initially and 2 weeks later) of 17 -estra-diol (E2) totaling 0.2 (2 x 0.1), 2.0 (2 x 1.0) or 20.0 (2 x 10.0) mg E2/kg body weight. Blood and tissue samples were collected 4, 6 and 8 weeks after the initial in...

  20. Dietary administration of Zooshikella sp. enhance the innate immune response and disease resistance of Paralichthys olivaceus against Sreptococcus iniae.

    PubMed

    Kim, Ju-Sang; Harikrishnan, Ramasamy; Kim, Man-Chul; Balasundaram, Chellam; Heo, Moon-Soo

    2010-07-01

    We report the growth, innate immune response, and disease resistance in olive flounder (Paralichthys olivaceus) challenged with Streptococcus iniae after feeding with diet enriched with Zooshikella sp. strain JE-34 three different concentration i.e. Low (3.4 x 10(4), n = 50), medium (3.5 x 10(6), n = 50), and high (3.4 x 10(8), n = 50) cfu ml(-1) supplemented diets, the changes were monitored on weeks 1, 2, 4, 8, 12, and 16. With all diets the innate immune parameters, such as superoxide anion production, phagocytic and lysozyme activity were not enhanced on week 1 and 4. On the other hand, all tested immune parameters in the treated groups significantly enhanced after 8th week; the weight gain significantly increased after 4th week in fish fed with enriched diets. The mortality in olive flounder after administration with high concentration diet showed 25%. With low and medium enriched diets the mortality was 40% and 35%, respectively. In the infected untreated group mortality was 85% while there was no mortality in the control group. The results suggested that Zooshikella sp. strain JE-34 enriched diets could be used to enhance the innate immune response and disease resistance of P. olivaceus against S. iniae.

  1. Optimization of the purification methods for recovery of recombinant growth hormone from Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Zang, Xiaonan; Zhang, Xuecheng; Mu, Xiaosheng; Liu, Bin

    2013-03-01

    This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone (r-fGH) was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield (2.605 mg L-1) than that from soluble protein (1.964 mg L-1). Of the tested recovery methods, addition of renaturing buffer (pH 8.5) into denatured inclusion body yielded the best recovery rate (17.9%). This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.

  2. Effects of dietary supplementation of citrus by-products fermented with a probiotic microbe on growth performance, innate immunity and disease resistance against Edwardsiella tarda in juvenile olive flounder, Paralichthys olivaceus (Temminck & Schlegel).

    PubMed

    Lee, B-J; Kim, S-S; Song, J-W; Oh, D-H; Cha, J-H; Jeong, J-B; Heo, M-S; Kim, K-W; Lee, K-J

    2013-07-01

    Two consecutive studies were conducted to evaluate the dietary supplementation of citrus by-products (CB) fermented with probiotic bacteria on growth performance, feed utilization, innate immune responses and disease resistance of juvenile olive flounder. In Experiment I, five diets were formulated to contain 0% (control) or 3% four different CB fermented with Bacillus subtilis (BS), Enterococcus faecium (EF), Lactobacillus rhamnosus (LR) and L. plantarum (LP) (designated as CON, CBF-BS, CBF-EF, CBF-LR and CBF-LP, respectively). During 10 weeks of a feeding trial, growth performance and feed efficiency were not significantly different among all the fish groups. However, fish fed CBF containing diets had significantly higher survivals than the CON group. Disease resistance of fish against Edwardsiella tarda was increased by the fermentation of CB. In Experiment II, we chose the BS as a promising probiotic and formulated five diets to contain 0%, 2%, 4%, 6% and 8% CBF-BS. Growth performance was not significantly affected by the CBF-BS supplementation during 6 weeks of a feeding trial. Innate immunity of fish was significantly enhanced by CBF-BS supplementation. Myeloperoxidase and lysozyme activities were increased in a dose-dependent manner by dietary CBF-BS inclusions. In a consecutive challenge test against E. tarda, an increased disease resistance was found by CBF-BS supplementation. These studies indicate that the fermentation process of CB with probiotic has beneficial effects on innate immunity and thereby increases disease resistance of olive flounder against E. tarda. Bacillus subtilis can be used as a promising probiotic microbe for by-product fermentation in fish feeds.

  3. A study on the meat and bone meal or poultry by-product meal as protein substitutes of fishmeal in concentrated diets for Paralichthys olivaceus

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Mai, Kangsen; Zhang, Baigang; Hu, Yangjiang; Yu, Yu

    2006-01-01

    A study was conducted to evaluate the effects of meat and bone meal (MBM) and poultry by-product meal (PBM) as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient (ADC) of Japanese flounder ( Paralichthys olivaceus). The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences ( P>0.05) in growth performance among the treatments fed with 0% 60% MBM replacement of fishmeal, while the percent weight gain (WG, %), body length gain (BLG, %) and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences ( P>0.05) in growth performance and ADC among all treatments fed with the diets with 0% 80% replacements of fishmeal with PBM.

  4. In vitro study on cytotoxic effects of the organopho-sphorous pesticide profenofos on the gill cell line, FG-9307, of the flounder ( Paralichihys olivaceus)

    NASA Astrophysics Data System (ADS)

    Li, Hong-Yan; Zhang, Shi-Cui; Jiang, Ming; Wang, Min

    2001-03-01

    The FG-9007 cell line derived from the gill of flounder Paralichthys olivaceus was used in the present study to determine the acute cytotoxic effects of the organophosphorous pesticide, profenofos. It was found that the cell growth rate was markedly reduced by profenofos at the concentrations of 2.5, 5 and 7.5 mg/L tested; and that the fine structures of the cells were also altered by profenofos, as evidenced by dilation of nuclear membranes and mitochondria cristae, and presence of enlarged lysosomes with engulfed organelles and numerous vacuoles in the cytoplasm. Probably, mitochondria, the cell energy-generating sites, are the most prominent sites of profenofos cytotoxity in the cells. This seems to be the first report of the use of marine fish cell line for evaluation of the acute in vitro cytotoxicity of organophosphorus pesticide.

  5. Spatial and temporal shifts in suitable habitat of juvenile southern flounder (Paralichthys lethostigma)

    NASA Astrophysics Data System (ADS)

    Furey, Nathan B.; Rooker, Jay R.

    2013-02-01

    Factors influencing suitable habitats of juvenile southern flounder (Paralichthys lethostigma) within the Galveston Bay Complex (GBC), Texas, were assessed using generalized additive models (GAM). Fishery independent data collected with bag seines throughout the GBC from 1999 to 2009 were used to predict the probability of southern flounder occurrence. Binomial GAMs were used to assess presence/absence of southern flounder and models included temporal variables, benthic variables such as distance to habitats generated within a geographic information system, and physicochemical conditions of the water column. Separate models were generated for newly settled southern flounder, young-of-the-year (YOY) southern flounder observed in the summer, and YOY southern flounder observed in fall based on size and collection month. Factors affecting southern flounder occurrence changed seasonally, as did the corresponding shifts in the spatial distribution of suitable habitat. Temporal effects (year and month) were retained in all models. Physicochemical conditions (temperature, turbidity, and measures of environmental variability), and the presence of seagrass beds were influential for newly settled southern flounder. Distance to marine and/or freshwater sources were found to be important for YOY southern flounder in the summer and fall seasons. The abundance of brown shrimp was found to only influence the distribution of YOY southern flounder in the fall, when intermediate abundances of the potential prey item increased the occurrence of southern flounder. After model completion, the availability and spatial distribution of suitable habitat within the GBC was predicted using available environmental and spatial data for 2005. Spatial distributions of predicted suitable habitat stress the relative importance of West Bay during the newly settled stage and in the fall season, and Upper Bay during the summer and fall of the first year of life. These models demonstrate the potential

  6. VITELLOGENIN-INDUCED PATHOLOGY AND MORTALITY IN MALE SUMMER FLOUNDER (PARALICHTHYS DENTATUS)

    EPA Science Inventory

    Male summer flounder (Paralichthys dentatus) were given two injections (initially and two weeks later) of 17 b-estradiol (E2) totaling 0.2 (2 x 0.1), 2.0 (2 x 1.0) or 20.0 (2 x 10.0) mg E2/kg body weight. Blood and tissue samples were collected 4, 6 and 8 weeks after the initial ...

  7. Temperature affects insulin-like growth factor I and growth of juvenile southern flounder, Paralichthys lethostigma.

    PubMed

    Luckenbach, J Adam; Murashige, Ryan; Daniels, Harry V; Godwin, John; Borski, Russell J

    2007-01-01

    Temperature profoundly influences growth of heterothermic vertebrates. However, few studies have investigated the effects of temperature on growth and insulin-like growth factor I (IGF-I) in fishes. The aim of this study was to examine effects of temperature on growth and establish whether IGF-I may mediate growth at different temperatures in southern flounder, Paralichthys lethostigma. In two experiments, juvenile flounder were reared at 23 and 28 degrees C and growth was monitored for either 117 or 197 days. Growth was similar across treatments in both experiments until fish reached approximately 100 mm total length. Body size then diverged with fish at 23 degrees C ultimately growing 65-83% larger than those at 28 degrees C. Muscle IGF-I mRNA, plasma IGF-I, and hepatosomatic index (HSI) were significantly higher in flounder at 23 degrees C, whereas hepatic IGF-I mRNA abundance did not differ with treatment. Muscle IGF-I mRNA was correlated with HSI, while plasma IGF-I was correlated with body size, hepatic IGF-I mRNA, and HSI. These results demonstrate a strong effect of temperature on flounder growth and show that temperature-induced variation in growth is associated with differences in systemic IGF-I and local (i.e., muscle) IGF-I mRNA levels. The results also support the use of plasma IGF-I and HSI as indicators of flounder growth status.

  8. Histochemistry of six lectins in the tissues of the flat fish Paralichthys olivaceus.

    PubMed

    Jung, Kyung-Sook; Ahn, Mee-Jung; Lee, Yong-Duk; Go, Gyung-Min; Shin, Tae-Kyun

    2002-12-01

    Lectins are glycoproteins that specifically bind carbohydrate structures and may participate in the biodefense mechanisms of fish. In this study, the binding of three lectins, Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), Bandeiraea simplicifolia BS-1 (isolectin B4), Triticum vulgaris (WGA), Arachis hypogaea (PNA) and Ulex europaeus (UEA-I) were studied in the gill, liver, intestine, kidney, heart, and spleen of the flat fish Paralichthys olivaceus. DBA was detected in intestinal mucous cells, as well as in gill epithelial and mucous cells. It was weakly detected in renal tubule epithelial cells and in bile duct epithelial cells. The strong SBA staining was seen in the intestinal club cells, in bile duct epithelial cells and renal tubule epithelial cells. There were intense positive reactions for isolectin B4 in gill epithelial and mucous cells, and the strong isolectin B4 staining was seen in epithelial cells of the bile duct and intestine. The strong WGA staining was seen in the gill mucosal cells, sinusoid, renal tubule epithelial cells and mucosal cells of the intestine. UEA-I was detected in the gill epithelial and mucosal cells, bile duct epithelial cells and renal tubular epithelial cells. These results suggest that the six lectins examined were localized in the covering epithelia of the various organs of the flat fish and they may participate in the biodefense mechanism of the intra body surface in which is exposed to various antigens.

  9. Fine Flounder (Paralichthys adspersus) Microbiome Showed Important Differences between Wild and Reared Specimens

    PubMed Central

    Ramírez, Carolina; Romero, Jaime

    2017-01-01

    The intestinal microbiota is involved in a wide range of biological processes that benefit the host, including providing nutrition and modulating the immune system. Fine flounder (Paralichthys adspersus) is a flatfish of commercial interest that is native to the Chilean coast. The high value of this flatfish has prompted the development of stock enhancement and aquaculture activities. Knowledge of microbiota may help to improve the cultivation of this species; however, few comparative studies have evaluated the intestinal microbiota composition in farmed versus wild fishes. Intestinal contents from wild and aquaculture fish were collected, and DNA was extracted. Subsequently, the V3-region of 16S rRNA was PCR amplified and sequenced using the Ion Torrent platform. The comparison between wild and aquaculture specimens revealed important differences in the composition of the microbiota. The most abundant phylum in wild flounder was Proteobacteria, with an average relative abundance of 68.1 ± 15.4%; in contrast, in aquaculture flounder, this phylum had an average relative abundance of 30.8 ± 24.1%. Reciprocally, the most abundant phylum in flounder aquaculture was Firmicutes, averaging 61.2 ± 28.4%; in contrast, this phylum showed low abundance in wild flounder, in which it averaged 4.7 ± 4%. The phylum Actinobacteria showed greater abundance in wild flounder, ranging from 21.7 ± 18.8%, whereas, it averaged only 2.7 ± 3.8% in aquaculture fish. Specific taxa that were differentially distributed between wild and aquaculture flounder were identified using a statistical approach. At the genus level, a total of four genera were differentially represented between the two conditions. Bacillus and Pseudomonas were more highly represented in aquaculture flounder, whereas Arthrobacter and Psychrobacter were observed in wild flounder. Furthermore, in both cases, predicted functions (metabolic pathways) indicated that those microbiota might provide beneficial effects for

  10. Spatial and temporal variability in growth of southern flounder (Paralichthys lethostigma)

    USGS Publications Warehouse

    Midway, Stephen R.; Wagner, Tyler; Arnott, Stephen A.; Biondo, Patrick; Martinez-Andrade, Fernando; Wadsworth, Thomas F.

    2015-01-01

    Delineation of stock structure is important for understanding the ecology and management of many fish populations, particularly those with wide-ranging distributions and high levels of harvest. Southern flounder (Paralichthys lethostigma) is a popular commercial and recreational species along the southeast Atlantic coast and Gulf of Mexico, USA. Recent studies have provided genetic and otolith morphology evidence that the Gulf of Mexico and Atlantic Ocean stocks differ. Using age and growth data from four states (Texas, Alabama, South Carolina, and North Carolina) we expanded upon the traditional von Bertalanffy model in order to compare growth rates of putative geographic stocks of southern flounder. We improved the model fitting process by adding a hierarchical Bayesian framework to allow each parameter to vary spatially or temporally as a random effect, as well as log transforming the three model parameters (L∞, K, andt0). Multiple comparisons of parameters showed that growth rates varied (even within states) for females, but less for males. Growth rates were also consistent through time, when long-term data were available. Since within-basin populations are thought to be genetically well-mixed, our results suggest that consistent small-scale environmental conditions (i.e., within estuaries) likely drive growth rates and should be considered when developing broader scale management plans.

  11. On the ecology of two sympatric flounders of the genus Paralichthys in the Bay of Coquimbo, Chile

    NASA Astrophysics Data System (ADS)

    Acuña, Enzo; Cid, Luis

    The ecology of two flounders belonging to the genus Paralichthys was studied in the Bay of Coquimbo (29°57'S), Chile. P. adspersus grows larger than P. microps. In both species, the females were significantly larger than the males. The species differed in their reproductive cycles as revealed by their gonadosomatic indices. This difference was also reflected in larval abundance and spatial distribution of the species. No significant changes were found in the abundances of juveniles and adults in the Bay of Coquimbo either throughout the year or interannually. However, when the analysis included the proportion of specimens between the two species and sex by season, the differences were apparent in most cases. The results show that the environmental characteristics of the marine system which the Bay of Coquimbo is a part of provide good feeding, spawning and nursery grounds for these two species of flounder.

  12. Juvenile winter flounder (Pseudopleuronectes americanus) and summer flounder (Paralichthys dentatus) utilization of Southern New England nurseries: Comparisons among estuarine, tidal river, and coastal lagoon shallow-water habitats.

    PubMed

    Taylor, David L; McNamee, Jason; Lake, John; Gervasi, Carissa L; Palance, Danial G

    2016-09-01

    This study evaluated the relative importance of the N arragansett Bay estuary (RI and MA, USA), and associated tidal rivers and coastal lagoons, as nurseries for juvenile winter flounder, Pseudopleuronectes americanus, and summer flounder, Paralichthys dentatus. Winter flounder (WF) and summer flounder (SF) abundance and growth were measured from May to October (2009-2013) and served as indicators for the use and quality of shallow-water habitats (water depth < 1.5-3.0 m). These bioindicators were then analyzed with respect to physiochemical conditions to determine the mechanisms underlying intra-specific habitat selection. WF and SF abundances were greatest in late May and June (maximum monthly mean = 4.9 and 0.55 flounder/m(2) for WF and SF, respectively), and were significantly higher in the tidal rivers relative to the bay and lagoons. Habitat-related patterns in WF and SF abundance were primarily governed by their preferences for oligohaline (0.1-5 ppt) and mesohaline (6-18 ppt) waters, but also their respective avoidance of hypoxic conditions (< 4 mg DO/L) and warm water temperatures (> 25 °C). Flounder habitat usage was also positively related to sediment organic content, which may be due to these substrates having sufficiently high prey densities. WF growth rates (mean = 0.25 ± 0.14 mm/d) were negatively correlated with the abundance of conspecifics, whereas SF growth (mean = 1.39 ± 0.46 mm/d) was positively related to temperature and salinity. Also, contrary to expectations, flounder occupied habitats that offered no ostensible advantage in intra-specific growth rates. WF and SF exposed to low salinities in certain rivers likely experienced increased osmoregulatory costs, thereby reducing energy for somatic growth. Low-salinity habitats, however, may benefit flounder by providing refugia from predation or reduced competition with other estuarine fishes and macro-invertebrates. Examining WF and SF abundance and growth across each species' broader

  13. Ocean acidification effects in the early life-stages of summer flounder, Paralichthys dentatus

    NASA Astrophysics Data System (ADS)

    Chambers, R. C.; Candelmo, A. C.; Habeck, E. A.; Poach, M. E.; Wieczorek, D.; Cooper, K. R.; Greenfield, C. E.; Phelan, B. A.

    2013-08-01

    The limited available evidence about effects of high CO2 and acidification of our oceans on fish suggests that effects will differ across fish species, be subtle, and interact with other stressors. An experimental framework was implemented that includes the use of (1) multiple marine fish species of relevance to the northeastern USA that differ in their ecologies including spawning season and habitat; (2) a wide yet realistic range of environmental conditions (i.e., concurrent manipulation of CO2 levels and water temperatures), and (3) a diverse set of response variables related to fish sensitivity to elevated CO2 levels, water temperatures, and their interactions. This report is on an array of early life-history responses of summer flounder (Paralichthys dentatus), an ecologically and economically important flatfish of this region, to a wide range of pH and CO2 levels. Survival of summer flounder embryos was reduced by 50% below local ambient conditions (7.8 pH, 775 ppm pCO2) when maintained at the intermediate conditions (7.4 pH, 1860 ppm pCO2), and by 75% below local ambient when maintained at the most acidic conditions tested (7.1 pH, 4715 ppm pCO2). This pattern of reduced survival of embryos at higher CO2 levels was consistent among three females used as sources of embryos. Sizes and shapes of larvae were altered by elevated CO2 levels with longer larvae in more acidic waters. This pattern of longer larvae was evident at hatching (although longer hatchlings had less energy reserves) to midway through the larval period. Larvae from the most acidic conditions initiated metamorphosis at earlier ages and smaller sizes than those from more moderate and ambient conditions. Tissue damage was evident in older larvae (age 14 to 28 d post-hatching) from both elevated CO2 levels. Damage included liver sinusoid dilation, focal hyperplasia on the epithelium, separation of the trunk muscle bundles, and dilation of the liver sinusoids and central veins. Cranial

  14. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (South Florida): Southern, gulf, and summer flounders. [Paralichthys lethostigma; Paralichthys albigutta; Paralichthys dentatus

    SciTech Connect

    Gilbert, C.R.

    1986-07-01

    The southern, gulf, and summer flounders live most of their lives in or near estuaries. Adults migrate into offshore waters during fall and winter, where spawning occurs from September to April. Eggs and newly-hatched larvae are carried inshore into estuaries, where further growth takes place. Age at sexual maturity for the three species has been estimated from 2 to 4 years, and maximum longevity from 3 to 10 years. Females apparently live slightly longer than males. Southern and summer flounders are estimated to live slightly longer than the smaller gulf flounder. Postlarvae eat mostly zooplankton, and larger individuals feed on fish and crustaceans. The summer and gulf flounders prefer a hard and/or sandy substrate, whereas the southern flounder is more common in a soft bottom of rich organic mud, clay, or silt. The southern flounder, unlike the other two species, is highly euryhaline, and frequently occurs in fresh water. Commercial catch statistics lump the three species together under the name ''flounder.'' Peak commercial catch in the Gulf of Mexico (in 1977) was 1.5 million lb, for a value of $561,000; peak catch in the south Atlantic region (also in 1977) was 11.4 million lb, for a value of $5,100,000.

  15. Distribution, condition, and growth of newly settled southern flounder ( Paralichthys lethostigma) in the Galveston Bay Estuary, TX

    NASA Astrophysics Data System (ADS)

    Glass, Lindsay A.; Rooker, Jay R.; Kraus, Richard T.; Holt, G. Joan

    2008-08-01

    Several flatfish species, including southern flounder ( Paralichthys lethostigma) recruit to estuaries during early life. Therefore, evaluation of estuarine sites and habitats that serve as nurseries is critical to conservation and management. The present study used density data in conjunction with biochemical condition and growth measurements to evaluate settlement sites used by southern flounder in the Galveston Bay Estuary (GBE). In 2005, beam-trawl collections were made in three major sections of the GBE (East Bay, Galveston Bay, West Bay). Three sites were sampled in each bay. Within each sampling site, replicate collections were taken from three habitats: 1) marsh edge (< 1 m depth), 2) intermediate zone (10-20 m from marsh interface; ˜ 1 m depth), and 3) bay zone (typically > 100 m from marsh interface; depth > 1 m). Average size of southern flounder collected was 12-19 mm standard length, and peak densities occurred in January and February. Catch data indicated that densities of southern flounder were significantly greater in East Bay (2.75 per 100 m 2) than in Galveston Bay (0.91 per 100 m 2) or in West Bay (0.45 per 100 m 2). Densities were statistically similar among habitats. Otolith-based estimates of age indicated that the majority of southern flounder collected were 35-45 days old and derived from early December to early January hatch-dates. Growth rates were similar among bays and among habitats, with the average growth rate being 0.40 mm day - 1 (range: 0.21-0.76 mm day - 1 ). RNA:DNA was above the established baseline value for nutritional stress, indicating that newly settled southern flounder in the GBE were in relatively high condition. Habitat-specific differences in RNA:DNA ratios were not observed; however, ratios were significantly lower in West Bay (average 8.0) than in East Bay (average 9.5) or in Galveston Bay (average 9.8), suggesting the condition of new recruits may vary spatially within the GBE. Findings from the current study

  16. Microsatellite analysis as a tool for discriminating an interfamily hybrid between olive flounder and starry flounder.

    PubMed

    Kang, J-H; Kim, Y-K; Park, J-Y; An, C-M; Nam, M-M; Byun, S G; Lee, B I; Lee, J H; Choi, T-J

    2011-10-31

    An interspecific artificial hybrid was produced between two economically important aquaculture flatfish: olive flounder (Paralichthys olivaceus) and starry flounder (P. stellatus). This hybrid displays the rapid growth characteristic of the former and tolerance to low temperatures and low salinity of the latter, but the genetics of inheritance in this hybrid have not been elucidated. Polymorphic microsatellite markers developed for P. olivaceus and P. stellatus were tested to determine if these markers can be used for analysis of parentage and genetic inheritance. Multiplex PCR using two primer sets that were specific to each species produced PCR products of different sizes; these could be used for the identification of interspecific hybrids. Among the 192 primers derived from olive flounder, 25.5% of the primer sets successfully amplified genomic DNA from starry flounder, and 23% of the 56 primer sets originating from starry flounder amplified DNA from olive flounder. Analysis of genetic inheritance in the hybrid using seven of the 62 microsatellite markers common to both species demonstrated classic Mendelian inheritance of these markers in the hybrid progeny, with the exception of one locus identified as a null allele in the hybrid. These results demonstrate that cross-specific microsatellite markers can be used tools for parentage analysis of hybrid flatfish, for mapping quantitative trait loci, for marker-assisted selective breeding, and for studies of the evolution of fish.

  17. Endocrine changes of Paralichthys olivaceus after oral administration with exogenous growth hormone

    NASA Astrophysics Data System (ADS)

    Liu, Zong-Zhu; Xu, De-Wu; Wang, Yong; Xu, Yong-Li; Zhang, Pei-Jun

    2000-12-01

    Recombinant salmon growth hormone contained in yeast was given for 5 months to flounder in its diet. Both free and total specific binding sites for the growth hormone were examined in liver membranes of control and treated fish. The association constants of both free and total specific binding sites were of the same order (1 nM-1), and no significant difference was found between any two groups in the capacity of their free binding sites. The capacity of total binding sites in the liver of treated fish increased significantly compared with that of control. Insulin-like growth factor I (IGF-I) levels in the plasma of treated fish increased by 22.61% (P<0.05), compared with that of control. While the T4 levels in plasma did not increase significantly (from 1.35±0.91 ng/ml to 2.29±1.13 ng/ml), T3 levels were elevated significantly (from 1.78±1.14 ng/ml to 4.87±1.22 ng/ml, P<0.01), as compared with that of control.

  18. Effects of modified atmosphere packaging on toxin production by Clostridium botulinum in raw aquacultured summer flounder fillets (Paralichthys dentatus).

    PubMed

    Arritt, Fletcher M; Eifert, Joseph D; Jahncke, Michael L; Pierson, Merle D; Williams, Robert C

    2007-05-01

    Packaging fishery products under vacuum atmosphere packaging (VAC) and modified atmosphere packaging (MAP) conditions can significantly extend the shelf life of raw, refrigerated fish products. There is considerable commercial interest in marketing VAC and MAP refrigerated (never frozen) raw fish fillets. The objective of this study was to determine if Clostridium botulinum toxin development precedes microbiological spoilage in raw, refrigerated flounder fillets. Aquacultured flounder (Paralichthys dentatus) individual fish fillets either were packed with a film having an oxygen transmission rate (OTR) of 3000 cm3 m(-2) 24 h(-1) at 22.8 degrees C or were vacuum packaged or packaged under 100% CO2 with a film having an OTR of 7.8 cm3 m(-2) 24 h(-1) at 21.1 degrees C and were stored at 4 and 10 degrees C. Samples were analyzed by aerobic plate count (APC) for spoilage and qualitatively for botulinum toxin with a mouse bioassay. The results demonstrate that flounder fillets (4 degrees C) packaged with a film having an OTR of 3,000 were microbiologically spoiled (APC, > 10(7) CFU/g) on day 15, but there was no toxin formation, even after 35 days of storage. However, at 10 degrees C, toxin production occurred (day 8), but it was after microbial spoilage and absolute sensory rejection (day 5). Vacuum-packaged fillets and 100% CO2 fillets (4 degrees C) packaged with a film having an OTR of 7.8 were toxic on days 20 and 25, respectively, with microbial spoilage (APC, >10(7) CFU/g) not occurring during the tested storage period (i.e., >35 days). At 10 degrees C, in vacuum-packaged flounder, toxin formation coincided with microbiological spoilage (days 8 to 9). In the 100% CO2-packaged fillets, toxin formation occurred on day 9, with microbial spoilage occurring on day 15. This study indicates that films with an OTR of 3,000 can be used for refrigerated fish fillets and still maintain the safety of the product.

  19. Inonotus obliquus containing diet enhances the innate immune mechanism and disease resistance in olive flounder Paralichythys olivaceus against Uronema marinum.

    PubMed

    Harikrishnan, Ramasamy; Balasundaram, Chellam; Heo, Moon-Soo

    2012-06-01

    The present study describes the effect of diet supplementation with Chaga mushroom, Inonotus obliquus extract at 0%, 0.01%, 0.1%, and 1.0% levels on the innate humoral (lysozyme, antiprotease, and complement), cellular responses (production of reactive oxygen and nitrogen species and myeloperoxidase), and disease resistance in olive flounder, Paralichythys olivaceus against Uronema marinum. The lysozyme activity and complement activity significantly increased in each diet on weeks 2 and 4 against pathogen. The serum antiprotease activity and reactive nitrogen intermediates production significantly increased in fish fed with 0.1% and 1.0% diets from weeks 1-4. However, reactive oxygen species production and myeloperoxidase activity significantly increased in 1.0% and 2.0% diets on weeks 2 and 4. In fish fed with 0.1% and 1.0% diets and challenged with U. marinum the cumulative mortality was 50% and 40% while in 0% and 0.01% diets the mortality was 85% and 55%. The results clearly indicate that supplementation diet with I. obliquus at 0.1% and 1.0% level positively enhance the immune system and confer disease resistance which may be potentially used as an immunoprophylactic in finfish culture.

  20. Distortion of frontal bones results from cell apoptosis by the mechanical force from the up-migrating eye during metamorphosis in Paralichthys olivaceus.

    PubMed

    Sun, Mingyan; Wei, Fen; Li, Hui; Xu, Juan; Chen, Xinye; Gong, Xiaoling; Tian, Yongsheng; Chen, Songlin; Bao, Baolong

    2015-05-01

    Craniofacial remodeling during flatfish metamorphosis, including eye migration, is perhaps the most striking example of asymmetric postembryonic development in the vertebrate world. The asymmetry of the cranium mainly results from distortion of the frontal bones, which depends on eye migration during metamorphosis. However, it is unclear how the up-migrating eye causes distortion of the frontal bones. In this study, we first show that distortion of the frontal bones during metamorphosis in Paralichthys olivaceus is the result of cell apoptosis, rather than cell autophagy or cell proliferation. Secondly, we report that cell apoptosis in the frontal bones is induced by the mechanical force transferred from the up-migrating eye. The mechanical force from the up-migrating eye signals through FAK to downstream molecules that are integrated into the BMP-2 signal pathway. Finally, it is shown that cell apoptosis in the frontal bones is activated by the intrinsic mitochondrial pathway; the extrinsic death receptor is not involved in this process. Moreover, cell apoptosis in frontal bones is not induced directly by thyroid hormones, which are thought to mediate metamorphosis in flatfishes and directly mediate cell apoptosis during amphibian metamorphosis. These findings help identify the major signaling route used during regulation of frontal bone distortion during metamorphosis in flatfish, and indicate that the asymmetry of the cranium, or at least the distortion of frontal bones, is the result of rather than the reason underlying eye migration.

  1. Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA)

    PubMed Central

    Hager, Christian; Diaddorio, Eric; Dickey, R. Jason

    2016-01-01

    Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given this conservation and management need, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon incidental encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 39.6% and 60.9%, respectively. Our design entangled 51.6% fewer southern flounder, which corresponded to a 48.9% reduction in total weight; the modified gear entangled slightly larger southern flounder than the control gear. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper (5.1–6.3 m) than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. Most southern flounder (n = 518, 39.7%) were taken at a water depth between 3.76 and 5.0 m. This observation suggests that southern flounder prefer slightly shallower waters than Atlantic sturgeon. PMID:27547524

  2. Commercial fishing gear modifications to reduce interactions between Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and the southern flounder (Paralichthys lethostigma) fishery in North Carolina (USA).

    PubMed

    Levesque, Juan C; Hager, Christian; Diaddorio, Eric; Dickey, R Jason

    2016-01-01

    Bycatch of protected species in commercial fishing operations is a primary concern to fishery managers because it threatens the conservation, protection, and recovery of fragile species, such as the Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus). One potential solution to reduce the risk associated with commercial fishing operations is to design commercial fishing gear that is more selective in terms of interactions between Atlantic sturgeon and commercial fisheries. Given this conservation and management need, the overarching goal was to reduce Atlantic sturgeon fishery interactions and maintain southern flounder (Paralichthys lethostigma) catch in North Carolina. The specific objectives of this study were to design and evaluate the effectiveness of a modified gillnet. Overall, the results proved that lowering the profile and amount of webbing had a beneficial impact at reducing Atlantic sturgeon incidental encounters and bycatch. The modified gillnet reduced bycatch and Atlantic sturgeon encounters by 39.6% and 60.9%, respectively. Our design entangled 51.6% fewer southern flounder, which corresponded to a 48.9% reduction in total weight; the modified gear entangled slightly larger southern flounder than the control gear. Our findings showed the number of Atlantic sturgeon encounters was positively associated with mean water depth, with more Atlantic sturgeon encountered in deeper (5.1-6.3 m) than shallower waters; 75% were encountered at depths between 4.6 and 6.1 m. Most southern flounder (n = 518, 39.7%) were taken at a water depth between 3.76 and 5.0 m. This observation suggests that southern flounder prefer slightly shallower waters than Atlantic sturgeon.

  3. Roles of GATA6 during Gonadal Development in Japanese Flounder: Gonadogenesis, Regulation of Gender-Related Genes, Estrogen Formation and Gonadal Function Maintenance

    PubMed Central

    Li, Zan; Liu, Xiumei; Sun, Yan; Liu, Jinxiang; Liu, Yuezhong; Wang, Mengxun; Zhang, Quanqi; Wang, Xubo

    2017-01-01

    GATA-binding protein 6 (GATA6), a highly-conserved transcription factor of the GATA family plays an important role in gonadal cell proliferation, differentiation and endoderm development. In this study, the full-length cDNA of GATA6 of Paralichthys olivaceus (Japanese flounder) was obtained. Phylogenetic, gene structure and synteny analyses demonstrated that GATA6 of P. olivaceus is homologous to that of teleosts and tetrapods. The P. olivaceus GATA6 transcript showed higher expression in testis than in ovary, demonstrating a sexually dimorphic gene expression. During embryonic development, the expression of P. olivaceus GATA6 increased at the blastula stage, demonstrating that GATA6 is involved in morphogenesis. Results of in situ hybridization showed that GATA6 signals were detected in Sertoli cells, oogonia and oocytes. Moreover, 17α methyl testosterone, a male hormone, could moderately upregulate P. olivaceus GATA6 and downregulate P. olivaceus aromatase CYP19A1 in testis cells. These results suggest that GATA6 may play an important role in gonadal development in P. olivaceus. This study provides valuable information on the function of P. olivaceus GATA6, laying the foundation for further development of breeding techniques in this species. PMID:28275215

  4. Ink from longfin inshore squid, Doryteuthis pealeii, as a chemical and visual defense against two predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis.

    PubMed

    Derby, Charles D; Tottempudi, Mihika; Love-Chezem, Tiffany; Wolfe, Lanna S

    2013-12-01

    Chemical and visual defenses are used by many organisms to avoid being approached or eaten by predators. An example is inking molluscs-including gastropods such as sea hares and cephalopods such as squid, cuttlefish, and octopus-which release a colored ink upon approach or attack. Previous work showed that ink can protect molluscs through a combination of chemical, visual, and other effects. In this study, we examined the effects of ink from longfin inshore squid, Doryteuthis pealeii, on the behavior of two species of predatory fishes, summer flounder, Paralichthys dentatus, and sea catfish, Ariopsis felis. Using a cloud assay, we found that ink from longfin inshore squid affected the approach phase of predation by summer flounder, primarily through its visual effects. Using a food assay, we found that the ink affected the consummatory and ingestive phase of predation of both sea catfish and summer flounder, through the ink's chemical properties. Fractionation of ink showed that most of its deterrent chemical activity is associated with melanin granules, suggesting that either compounds adhering to these granules or melanin itself are the most biologically active. This work provides the basis for a comparative approach to identify deterrent molecules from inking cephalopods and to examine neural mechanisms whereby these chemicals affect behavior of fish, using the sea catfish as a chemosensory model.

  5. Transcriptional dynamics of immune, growth and stress related genes in skeletal muscle of the fine flounder (Paralichthys adpersus) during different nutritional statuses.

    PubMed

    Valenzuela, Cristián A; Escobar, Daniela; Perez, Lorena; Zuloaga, Rodrigo; Estrada, Juan Manuel; Mercado, Luis; Valdés, Juan Antonio; Molina, Alfredo

    2015-11-01

    The effects of stress on immune activity and growth in early vertebrates have not been studied in detail. The present study used fine flounder (Paralichthys adspersus) skeletal muscle as a model to evaluate molecules involved in the stress response, including the glucocorticoid receptors, foxo1/3, and the target genes of these. Additionally, immune markers (il-1β and tnfα) and effector molecules of atrophy (bnip3, caspase-3, and lc3) were assessed. These molecules were analyzed during periods of long-term fasting and refeeding. During fasting, gene expression related to the stress response and atrophy increased; whereas immune markers were down-regulated. During refeeding, atrophy- and stress-related gene expression significantly decreased. In contrast, immune markers were up-regulated. These results provide novel insight on the control of growth in the skeletal muscle of a non-mammalian species under a stressful condition, suggesting that growth, stress, and immune activity in muscle are closely related and coordinated by orchestrated transcriptional dynamics.

  6. Properties of proteolytic toxin of Vibrio anguilolarum from diseased flounder

    NASA Astrophysics Data System (ADS)

    Mo, Zhao-Lan; Chen, Shi-Yong; Zhang, Pei-Jun

    2002-12-01

    Extracellular products (ECP) produced by Vibrio anguillarum strain M3 originally isolated from diseased flounder ( Paralichthys olivaceus) were prepared. ECP of M3 showed gelatinase, casinase, amylase and haemolytic activity on agarose plates. High protease activity against azocasin was detected. Bacterium M2 showed highest growth and protease activity at 25°C. The protease present in ECP showed maximal activity at pH 8 and 55°C; was completely inactivated by application of 80°C heat for 30 min; was completely inhibited by EDTA and HgCl2, and was partially inhibited by PMSF, SDS, MnCl2 and iodoacetic acid; but not inhibited by CaCl2 and MgCl2. The ECP was toxic to flounder fish at LD50 values of 3.1 μg protein/g body weight. The addition of HgCl2 and application of heat at 50°C decreased the lethal toxicity of ECP. When heated at 100°C, ECP lethality to flounder was completely inhibited. After intramuscular injection of ECP into flounder, it showed evident histopathological changes including necrosis of muscle, extensive deposition of haemosiderin in the spleen, dilated blood vessels congested with numerious lymphocytes in the liver. These results showed that ECP protease was a lethal factor produced by the bacterium V. anguillarum M3.

  7. Edwardsiella tarda and Aeromonas hydrophila isolated from diseased Southern flounder (Paralichthys lethostigma) are virulent to channel catfish and Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study is to identify bacterial pathogens isolated from diseased Southern flounder and determine their virulence to channel catfish and Nile tilapia. Twenty five Gram-negative bacteria isolates were recovered from five tissues (skin lesions, brain, liver, intestine, and posterior kidn...

  8. Early development of circadian rhythmicity in the suprachiamatic nuclei and pineal gland of teleost, flounder (Paralichthys olivaeus), embryos.

    PubMed

    Mogi, Makoto; Uji, Susumu; Yokoi, Hayato; Suzuki, Tohru

    2015-08-01

    Circadian rhythms enable organisms to coordinate multiple physiological processes and behaviors with the earth's rotation. In mammals, the suprachiasmatic nuclei (SCN), the sole master circadian pacemaker, has entrainment mechanisms that set the circadian rhythm to a 24-h cycle with photic signals from retina. In contrast, the zebrafish SCN is not a circadian pacemaker, instead the pineal gland (PG) houses the major circadian oscillator. The SCN of flounder larvae, unlike that of zebrafish, however, expresses per2 with a rhythmicity of daytime/ON and nighttime/OFF. Here, we examined whether the rhythm of per2 expression in the flounder SCN represents the molecular clock. We also examined early development of the circadian rhythmicity in the SCN and PG. Our three major findings were as follows. First, rhythmic per2 expression in the SCN was maintained under 24 h dark (DD) conditions, indicating that a molecular clock exists in the flounder SCN. Second, onset of circadian rhythmicity in the SCN preceded that in the PG. Third, both 24 h light (LL) and DD conditions deeply affected the development of circadian rhythmicity in the SCN and PG. This is the first report dealing with the early development of circadian rhythmicity in the SCN in fish.

  9. Metamorphic pitx2 expression in the left habenula correlated with lateralization of eye-sidedness in flounder.

    PubMed

    Suzuki, Tohru; Washio, Youhei; Aritaki, Masato; Fujinami, Yuichiro; Shimizu, Daisuke; Uji, Susumu; Hashimoto, Hisashi

    2009-12-01

    The bilateral symmetry of flounder larvae changes through the process of morphogenesis to produce external asymmetry at metamorphosis. The process is characterized by the lateral migration of one eye and pigmentation at the ocular side. Migration of the left or right eye to produce either dextral or sinistral forms, respectively, is usually fixed within a species. Here we propose a mechanism for the mediation of lateralization by the nodal-lefty-pitx2 (NLP) pathway in flounders, in which pitx2, the final left-right determinant of the NLP pathway, is re-expressed in the left habenula at pre-metamorphosis. After the initiation of left-sided pitx2 re-expression, the eye commences migration, when the habenulae shift their position on the ventral diencephalon rightwards in sinistral flounder (Paralichthys olivaceus) and leftwards in dextral flounder (Verasper variegatus). In addition, the right habenula increases in size relative to the left habenula in both species. Loss of pitx2 re-expression induces randomization of eye-sidedness, manifesting as normal, reversed or bilateral symmetry, with laterality of the structural asymmetry of habenulae being entirely inverted in reversed flounders compared with normal ones. Thus, flounder pitx2 appears to be re-expressed in the left habenula at metamorphosis to direct eye-sidedness by lateralizing the morphological asymmetry of the habenulae.

  10. Effects of elevated CO2 in the early life stages of summer flounder, Paralichthys dentatus, and potential consequences of ocean acidification

    NASA Astrophysics Data System (ADS)

    Chambers, R. C.; Candelmo, A. C.; Habeck, E. A.; Poach, M. E.; Wieczorek, D.; Cooper, K. R.; Greenfield, C. E.; Phelan, B. A.

    2014-03-01

    The limited available evidence about effects on marine fishes of high CO2 and associated acidification of oceans suggests that effects will differ across species, be subtle, and may interact with other stressors. This report is on the responses of an array of early life history features of summer flounder (Paralichthys dentatus), an ecologically and economically important flatfish of the inshore and nearshore waters of the Mid-Atlantic Bight (USA), to experimental manipulation of CO2 levels. Relative survival of summer flounder embryos in local ambient conditions (775 μatm pCO2, 7.8 pH) was reduced to 48% when maintained at intermediate experimental conditions (1808 μatm pCO2, 7.5 pH), and to 16% when maintained at the most elevated CO2 treatment (4714 ppm pCO2, 7.1 pH). This pattern of reduced survival of embryos at high-CO2 levels at constant temperature was consistent among offspring of three females used as experimental subjects. No reduction in survival with CO2 was observed for larvae during the first four weeks of larval life (experiment ended at 28 d post-hatching (dph) when larvae were initiating metamorphosis). Estimates of sizes, shapes, and developmental status of larvae based on images of live larvae showed larvae were initially longer and faster growing when reared at intermediate- and high-CO2 levels. This pattern of longer larvae - but with less energy reserves at hatching - was expressed through the first half of the larval period (14 dph). Larvae from the highest-CO2 conditions initiated metamorphosis at earlier ages and smaller sizes than those from intermediate- and ambient-CO2 conditions. Tissue damage was evident in larvae as early as 7 dph from both elevated-CO2 levels. Damage included dilation of liver sinusoids and veins, focal hyperplasia on the epithelium, and separation of the trunk muscle bundles. Cranio-facial features changed with CO2 levels in an age-dependent manner. Skeletal elements of larvae from ambient-CO2 environments were

  11. Antioxidative responses and bioaccumulation in Japanese flounder larvae and juveniles under chronic mercury exposure.

    PubMed

    Huang, Wei; Cao, Liang; Ye, Zhenjiang; Yin, Xuebo; Dou, Shuozeng

    2010-06-01

    This study investigated the sub-lethal effects of waterborne mercury on growth, bioaccumulation and antioxidative responses of larvae and juveniles of Japanese flounder (Paralichthys olivaceus). Fish were exposed to 0-10 microg Hg(2)(+)L(-1) solutions from embryonic to the juvenile stages for 80 days. Antioxidative responses to mercury exposure were studied in metamorphosing larvae (18 days post hatching, dph), settling larvae (33 dph) and juveniles (78 dph). Results showed that increasing mercury concentration led to increased mercury bioaccumulation and reduced flounder growth. Of the antioxidants investigated, superoxide dismutase (SOD) and catalase (CAT) activities at the three developmental stages were sensitive to mercury exposure and increased with increasing mercury concentration. Glutathione (GSH) content was elevated in metamorphosing larvae, but decreased in juveniles as mercury concentration increased. Glutathione-S-transferase (GST) activity did not significantly vary with mercury concentration in either larvae or juveniles. Mercury exposure did not affect malondialdehyde (MDA) content of larvae, but significantly increased MDA content of juveniles. Results suggest that flounder larvae and juveniles have the potential to manipulate the levels of antioxidants such as SOD, CAT and GSH, which protect flounder from oxidative stress induced by mercury exposure. These antioxidants could serve as biomarkers of mercury contamination in the aquatic environment.

  12. Microarray analysis of gene expression in olive flounder liver infected with viral haemorrhagic septicaemia virus (VHSV).

    PubMed

    Cho, Hyun Kook; Kim, Julan; Moon, Ji Young; Nam, Bo-Hye; Kim, Young-Ok; Kim, Woo-Jin; Park, Jung Youn; An, Cheul Min; Cheong, Jaehun; Kong, Hee Jeong

    2016-02-01

    The most fatal viral pathogen in olive flounder Paralichthys olivaceus, is viral hemorrhagic septicemia virus, which afflicts over 48 species of freshwater and marine fish. Here, we performed gene expression profiling on transcripts isolated from VHSV-infected olive flounder livers using a 13 K cDNA microarray chip. A total of 1832 and 1647 genes were upregulated and down-regulated over two-fold, respectively, after infection. A variety of immune-related genes showing significant changes in gene expression were identified in upregulated genes through gene ontology annotation. These genes were grouped into categories such as antibacterial peptide, antigen-recognition and adhesion molecules, apoptosis, cytokine-related pathway, immune system, stress response, and transcription factor and regulatory factors. To verify the cDNA microarray data, we performed quantitative real-time PCR, and the results were similar to the microarray data. In conclusion, these results may be useful for the identification of specific genes or for the diagnosis of VHSV infection in flounder.

  13. Genetic variants of Kudoa septempunctata (Myxozoa: Multivalvulida), a flounder parasite causing foodborne disease.

    PubMed

    Takeuchi, F; Ogasawara, Y; Kato, K; Sekizuka, T; Nozaki, T; Sugita-Konishi, Y; Ohnishi, T; Kuroda, M

    2016-06-01

    Foodborne disease outbreaks caused by raw olive flounders (Paralichthys olivaceus) parasitized with Kudoa septempunctata have been reported in Japan. Origins of olive flounders consumed in Japan vary, being either domestic or imported, and aquaculture-raised or natural. Although it is unknown whether different sources are associated with different outcomes, it is desirable to identify whether this is the case by determining whether unique K. septempunctata strains occur and if so, whether some are associated with foodborne illness. We here developed an intraspecific genotyping method, using the sequence variation of mitochondrial genes. We collected olive flounder samples from foodborne disease outbreaks, domestic fish farms or quarantine offices and investigated whether K. septempunctata genotype is associated with pathogenicity or geographic origin. The 104 samples were classified into three genotypes, ST1, ST2 and ST3. Frequency of symptomatic cases differed by genotypes, but the association was not statistically significant. Whereas K. septempunctata detected from aquaculture-raised and natural fish from Japan were either ST1 or ST2, those from fish inspected at quarantine from Korea to Japan were ST3. Our method can be applied to phylogeographic analysis of K. septempunctata and contribute to containing the foodborne disease. The genotype database is hosted in the PubMLST website (http://pubmlst.org/kseptempunctata/).

  14. Poly(lactic-co-glycolic acid) nanoparticles as candidate DNA vaccine carrier for oral immunization of Japanese flounder (Paralichthys olivaceus) against lymphocystis disease virus.

    PubMed

    Tian, Jiyuan; Yu, Juan

    2011-01-01

    In order to protect DNA vaccine against degradation in alimentary tract of fish, poly(lactic-co-glycolic acid) (PLGA) nanoparticles encapsulating vaccine were prepared using W/O/W emulsification combined with spray drying technique in our laboratory. The characteristics of PLGA nanoparticles were described as follows: (1) shape, spherical; (2) size, <500 nm; (3) yield, ∼96.2%; loading percentage, ∼0.5%; encapsulation efficiency, ∼63.7%; supercoiled conformation percentage, ∼65%; (4) release dynamics, gradual release. In vitro transfection in SISK cells showed that PLGA nanoparticles could be utilized to transfect eukaryotes. After oral administration, FITC-labeled PLGA nanoparticles were detected in blood of fish, and RNA containing major capsid protein (MCP) gene information existed in various tissues of fish 10-90 days. In addition, the analysis of immune parameters in sera of treatment fish showed that: (1) infection rate of LCDV post-challenge, ∼16.7%; (2) prophenoloxidase, superoxide dismutase, respiratory burst, lysozyme and antibody levels, increased significantly (p<0.05); (3) activities of serum complement, changed a little (p>0.05). Pearson's correlation displayed that correlation of immune factors mentioned above (not including serum complement) were all positive for fish vaccinated. The data in this study suggested that PLGA nanoparticles were promising carriers for plasmid DNA vaccine and might be used to vaccinate fish by oral approach.

  15. Ontogeny of anti-viral hemorrhagic septicemia virus (VHSV) immunity in developing Japanese flounder.

    PubMed

    Matsuyama, Tomomasa; Nakayasu, Chihaya; Fujiwara, Atsushi; Kurita, Jun; Takano, Tomokazu; Ito, Takafumi; Sano, Motohiko

    2012-07-01

    We examined the ability of developing Japanese flounder (Paralichthys olivaceus) to acquire protective immunity after exposure to viral hemorrhagic septicemia virus (VHSV). Juveniles measuring 9.8 cm average body length were not susceptible to infection with VHSV at 20 °C, while the smaller fish were susceptible. Mortality was not observed after secondary infection at 15 °C in the 9.8 cm cohort that had previously been exposed to the virus at 20 °C, while the smaller fish were susceptible to secondary infection. The expression of interferon (IFN)-related genes was shown to be better developed in larger fish upon virus infection and basal expression levels of the virus recognition proteins were higher in larger fish. Virus-specific antibody was detected in the larger fish, but not in smaller fish. These data indicate that the largest juvenile (9.8 cm) acquired immunity against VHSV infection at the first virus challenge, but smaller fish did not. The anti-viral immune system in the Japanese flounder matures when juveniles reach approximately 10 cm.

  16. A cDNA microarray analysis to identify genes involved in the acute-phase response pathway of the olive flounder after infection with Edwardsiella tarda.

    PubMed

    Moon, Ji Young; Hong, Yong-Ki; Kong, Hee Jeong; Kim, Dong-Gyun; Kim, Young-Ok; Kim, Woo-Jin; Ji, Young Joo; An, Cheul Min; Nam, Bo-Hye

    2014-09-15

    The acute-phase response (APR) is an important systemic reaction that occurs within hours of an inflammatory signal caused by physical bodily injury or microbial infection. To investigate the APR of the olive flounder (Paralichthys olivaceus) following infection with a pathogen, we established an expressed sequence tag (EST)-based cDNA microarray chip composed of 13,061 PCR-amplified cDNAs encoding unique genes selected from an olive flounder EST analysis. Microarray analyses showed that the set of genes involved in the APR was strongly up-regulated in the liver of the olive flounder after infection with Edwardsiella tarda. Among the up-regulated genes, catechol-O-methyltransferase domain-containing protein 1, six-transmembrane prostate protein, haptoglobin precursor, and toll-like receptor 5 soluble form were particularly strongly up-regulated. Interestingly, the toll-like receptor 5 soluble form, which has not yet been detected in mammals, was up-regulated as much as 250-fold upon E. tarda infection. These results suggest that the APR mechanism of fish may be regulated differently from that of mammals. The data described here contribute toward our collective understanding of APR, especially in fish.

  17. High temperature induces cyp26b1 mRNA expression and delays meiotic initiation of germ cells by increasing cortisol levels during gonadal sex differentiation in Japanese flounder.

    PubMed

    Yamaguchi, Toshiya; Kitano, Takeshi

    2012-03-09

    The Japanese flounder (Paralichthys olivaceus) is a teleost fish with an XX/XY sex determination system. XX flounder can be induced to develop into phenotypic females or males, by rearing them at 18°C or 27°C, respectively, during the sex differentiation period. Therefore, the flounder provides an excellent model to study the molecular mechanisms underlying temperature-dependent sex determination. We previously showed that cortisol, the major glucocorticoid produced by the interrenal cells in teleosts, causes female-to-male sex reversal by directly suppressing mRNA expression of ovary-type aromatase (cyp19a1), a steroidogenic enzyme responsible for the conversion of androgens to estrogens in the gonads. Furthermore, an inhibitor of cortisol synthesis prevented masculinization of XX flounder at 27°C, suggesting that masculinization by high temperature is due to the suppression of cyp19a1 mRNA expression by elevated cortisol levels during gonadal sex differentiation in the flounder. In the present study, we found that exposure to high temperature during gonadal sex differentiation upregulates the mRNA expression of retinoid-degrading enzyme (cyp26b1) concomitantly with masculinization of XX gonads and delays meiotic initiation of germ cells. We also found that cortisol induces cyp26b1 mRNA expression and suppresses specific meiotic marker synaptonemal complex protein 3 (sycp3) mRNA expression in gonads during the sexual differentiation. In conclusion, these results suggest that exposure to high temperature induces cyp26b1 mRNA expression and delays meiotic initiation of germ cells by elevating cortisol levels during gonadal sex differentiation in Japanese flounder.

  18. Metamorphosis of summer flounder, Paralichthys dentatus: cell proliferation and differentiation of the gastric mucosa and developmental effects of altered thyroidal status.

    PubMed

    Soffientino, B; Specker, J L

    2001-06-15

    Summer flounder, like most marine fishes studied to date, are stomachless at first feeding, and subsequently acquire gastric function during the process of metamorphosis. Stomach formation is controlled largely by thyroxine (T4). In the present work we sought to understand gastric organogenesis in terms of cell proliferation and its relationship to histological differentiation. The objectives of the study were (1) to obtain a developmental pattern of cell proliferation in the gastric mucosa and to relate that pattern to the progress of gastric differentiation; and (2) to understand the regulatory role of T4 on cell proliferation and histological differentiation by altering the thyroidal status of the developing larvae. We observed that (1) in normally developing larvae, cell proliferation increased by early metamorphic climax (MC), remained high until mid-MC, and decreased to basal levels by late MC; concomitantly, the gastric glands appeared and differentiated in the fundic mucosa, and were complete by late MC; (2) T4 accelerated the differentiation of gastric glands and mucus neck cells, while inhibiting the concomitant increase in cell proliferation observed in controls; and (3) the goitrogen thiourea inhibited both cell proliferation and gastric differentiation compared to controls. These results indicate that T(4) is necessary for the three-fold increase in cell proliferation that occurs in early metamorphic climax, but that high T4 levels promote differentiation at the expense of proliferation. The observed effects would be consistent with the normal, metamorphosis-related increase in whole body T4.

  19. OCCURRENCE AND ORIENTATION OF PARALICHTHID FLOUNDERS (BOTHIDAE: PARALICHTYS) ON AN INTERTIDAL BEACH

    EPA Science Inventory

    Middaugh, Douglas P. and Charles L. McKenney, Jr. 2003. Occurrence and Orientation of Flounders (Bothidae: Paralichthys) on an Intertidal Beach. J. North Carol. Acad. Sci. 119(4):157-171. (ERL,GB 1172).

    The intertidal movement and burying pattern of paralichthid flounders...

  20. Live vaccine of viral hemorrhagic septicemia virus (VHSV) for Japanese flounder at fish rearing temperature of 21°C instead of Poly(I:C) administration.

    PubMed

    Nishizawa, Toyohiko; Takami, Ikuo; Yang, Minji; Oh, Myung-Joo

    2011-10-26

    The process of "Poly(I:C) immunization" involves immunization of fish with a pathogenic live virus, followed by administration of Poly(I:C), which induces a transient, non-specific antiviral state. As a result, fish in an antiviral state survive the initial immunization with live virus. Moreover, these fish are able to mount a specific protective immune response against the injected pathogenic virus. In the present study, we investigated the optimum temperature for Poly(I:C) immunization of Japanese flounder Paralichthys olivaceus with live viral hemorrhagic septicemia virus (VHSV). It was revealed that the optimum temperature was around at 17°C for Poly(I:C) immunization in Japanese flounder. Furthermore, the protection efficacy of Poly(I:C) immunization was significantly decreased by elevation of fish rearing temperature, and no efficacy was observed at a fish rearing temperature of 25°C. Interestingly, no mortality by VHSV infection was observed in fish reared at 21°C and 25°C even when those fish were not administered Poly(I:C). All of the survivors from the first VHSV-challenge at 21°C were strongly protected from re-challenge with VHSV. However, almost all of the survivors (≥82.6%) from the first challenge at 25°C were lost by the second challenge with VHSV. It was thus concluded that by rearing fish at 21°C and challenging with live VHSV, it is possible to induce strong specific immunity in Japanese flounder without Poly(I:C) administration.

  1. EFFECT OF ESTROGENIC (O,P'-DDT; OCTOPHENOL AND ANTI-ANDROGENIC (P'P'-DDE) CHEMICALS ON INDICATORS OF ENDOCRINE STATUS IN JUVENILE MALE SUMMER FLOUNDER (PARALICHTHYS DENTATUS)

    EPA Science Inventory

    Laboratory experiments were conducted with male summer flounder to assess the value of selected measures of endocrine status in fish as indicators of exposure to endocrine-disrupting contaminants. Efficts of 1,1,1-trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl) ethane
    (o,p'-D...

  2. The influence of cage conditioning on the performance and behavior of Japanese flounder reared for stock enhancement: Burying, feeding, and threat response

    NASA Astrophysics Data System (ADS)

    Walsh, Michelle L.; Masuda, Reiji; Yamashita, Yoh

    2014-01-01

    Flatfish reared for stock enhancement often exhibit irregular behavioral patterns compared with wild conspecifics. These “deficits”, mostly attributed to the unnatural characteristics of the hatchery environment, are assumed to translate to increased predation risk. Initially releasing fish in predator-free conditioning cages may help flatfish adjust to the wild environment, establish burial skills, begin pigment change, recover from transport stress, and experience natural (live) food sources before full release into the wild. However, the impact of cage conditioning on the performance and behavior of flatfish has yet to be fully assessed. We conducted video trials with 10-cm, hatchery-reared Japanese flounder, Paralichthys olivaceus, in sand-bottomed aquaria to assess four treatments of flounder: (1) reared fish cage conditioned for 7 d in the shallow coast, (2) reared fish directly from hatchery tanks, (3) wild fish, and (4) reared fish released directly from hatchery tanks into the wild and then recaptured after 6 d at large. Burying ability, predation, and threat response to a model predator were examined. Wild fish buried most, followed by cage conditioned, and released-then-recaptured and non-conditioned (directly from tank) fish. Wild and conditioned fish revealed much lower variation in total movement duration, which corresponded with lower levels and variation in prey vertical movement. Fish of all condition types exhibited a lower number of attacks and off-bottom swimming events, and a lower movement duration when the model predator was in motion versus when it was still. This study is the first to evaluate the behavioral mechanisms of hatchery-reared flatfish that have been cage-conditioned or released-then-recaptured. In addition, we provide evidence that cage conditioning can enhance the performance of released flatfish.

  3. THE PATHOBIOLOGY OF 17B-ESTRADIOL IN SUMMER FLOUNDER, PARALICHTYS DENTATUS

    EPA Science Inventory

    Estradiol has been shown to cause increased vitellogenin (VtG) concentrations in male fish. The intent of this study was to evaluate the pathobiology associated with exposure to 17 -estradiol (E2) on liver, gonad, and kidney tissues of summer flounder, Paralichthys dentatus. Juve...

  4. CONSUMPTIONS RATES OF SUMMER FLOUNDER LARVAE ON ROTIFER AND BRINE SHRIMP PREY DURING LARVAL REARING

    EPA Science Inventory

    Larval summer flounder Paralichthys dentatus were hatched and reared through metamorphosis in the laboratory. At several points in the rearing cycle, larvae were removed from their rearing chambers and placed in small bowls, where they were fed known quantities of the rotifer Bra...

  5. Direct and indirect effects of southern flounder predation on a spot population: Experimental and model analyses

    SciTech Connect

    Crowder, L.B.; Wright, R.A.; Martin, T.H.; Rice, J.A. . Dept. of Zoology); Rose, K.A. )

    1992-01-01

    We have previously shown that southern flounder (Paralichthys lethostigma Jordan and Gilbert) influence the survival and size-distribution of spot (Leiostomus xanthurus Lafayette) and other small estuarine fishes in experimental ponds. In this paper, we seek to determine whether these of effects can be accounted for by direct size-dependent predation or if there is also evidence for indirect behavioral effects on spot foraging which might alter their survival or population size structure. In our experiment, spot were allowed to grow in the presence and absence of southern flounder in an experimental estuarine pond for 101 days. Each treatment was replicated three times. We also apply a recently published simulation model of the flounder-spot interaction to this experiment to independently test the model and to estimate the direct effects of flounder predation on spot survival and size structure.

  6. EFFECT OF 17B-ESTRADIOL, O,P'-DDT, OCTYLPHENOL AND P,P'-DDE ON GONADAL DEVELOPMENT AND LIVER AND KIDNEY PATHOLOGY IN JUVENILE MALE SUMMER FLOUNDER (PARALICHTYS DENTATUS)

    EPA Science Inventory

    The intent of this study was to compare histopathologically the effect of 17 -estradiol (E2), o,p' DDT, octylphenol and p,p' DDE on gonadal development and liver and kidney condition in sexually immature (juvenile) summer flounder (Paralichthys dentatus). The dorsal sinus of 2-...

  7. Mercury accumulation and the mercury-PCB-sex interaction in summer flounder

    USGS Publications Warehouse

    Madenjian, Charles P.; Jensen, Olaf P.; Krabbenhoft, David P.; DeWild, John F.; Ogorek, Jacob M.; Vastano, Anthony R.

    2016-01-01

    Patterns in the relative differences in contaminant concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish total mercury (Hg) concentrations in 23 female summer flounder (Paralichthys dentatus) and 27 male summer flounder from New Jersey coastal waters. To estimate the change in Hg concentration due to release of eggs at spawning, Hg concentration in the somatic tissue and ovaries of 5 of the 23 female summer flounder were also determined. To ascertain whether most of the Hg in the summer flounder was methylmercury (MeHg), whole-fish MeHg concentrations were determined in all 50 summer flounder. Whole-fish Hg concentrations averaged 113 ng/g for females and 111 ng/g for males. Thus, females were 2% higher in Hg concentration than males, on average, but the difference was not statistically significant. Based on Hg determinations in the somatic tissue and ovaries, we predicted that Hg concentration of females would increase by 3.6%, on average, immediately after spawning due to release of eggs. On average, 92% of the Hg in the summer flounder was MeHg. To determine whether the effect of sex on Hg concentration was significantly different from the effect of sex on polychlorinated biphenyl (PCB) concentration, we paired our Hg determinations with PCB determinations from a previous study, and applied regression analysis. Sex significantly interacted with contaminant type (Hg or PCBs), as males were 43% higher in PCB concentration than females, whereas females were 2% higher in Hg concentration than males. Males eliminating Hg from their bodies at a faster rate than females was a likely explanation for this discrepancy between the two contaminant types. Overall, the Hg and PCB concentrations in the summer flounder were relatively low, and therefore our findings also had implications for continued operation of the summer flounder fishery.

  8. Responses of juvenile southern flounder exposed to Deepwater Horizon oil-contaminated sediments.

    PubMed

    Brown-Peterson, Nancy J; Krasnec, Michelle O; Lay, Claire R; Morris, Jeffrey M; Griffitt, Robert J

    2016-09-27

    The Deepwater Horizon oil spill released millions of barrels of crude oil into the northern Gulf of Mexico, much of which remains associated with sediments and can have continuing impacts on biota. Juvenile southern flounder (Paralichthys lethostigma) were exposed for 28 d in the laboratory under controlled conditions to reference and Deepwater Horizon oil-contaminated sediments collected from coastal Louisiana to assess the impacts on an ecologically and commercially important benthic fish. The measured polycyclic aromatic hydrocarbon (PAH) concentrations in the sediments ranged from 0.25 mg/kg to 3940 mg/kg suite of 50 PAH analytes (tPAH50). Mortality increased with both concentration and duration of exposure. Exposed flounder length and weight was lower compared to controls after 28 d of exposure to the sediments with the highest PAH concentration, but condition factor was significantly higher in these fish compared with all other treatments. Histopathological analyses showed increased occurrence of gill abnormalities, including telangiectasis, epithelial proliferation, and fused lamellae in flounder exposed to sediments with the highest tPAH50 concentrations. In addition, hepatic vascular congestion and macrovesicular vacuolation were observed in flounder exposed to the more contaminated sediments. These data suggest that chronic exposure to field collected oil-contaminated sediments results in a variety of sublethal impacts to a benthic fish, with implications for long-term recovery from oil spills. Environ Toxicol Chem 2016;9999:1-10. © 2016 SETAC.

  9. Electron microscope evidence of virus infection in cultured marine fish

    NASA Astrophysics Data System (ADS)

    Sun, Xiu-Qin; Zhang, Jin-Xing; Qu, Ling-Yun

    2000-09-01

    Electron microscope investigation on the red sea bream ( Pagrosomus major), bastard halibut ( Paralichthys olivaceus) and stone flounder ( Kareius bicoloratus) in North China revealed virus infection in the bodies of the dead and diseased fish. These viruses included the lymphocystis disease virus (LDV), parvovirus, globular virus, and a kind of baculavirus which was not discovered and reported before and is now tentatively named baculavirus of stone flounder ( Kareius bicoloratus).

  10. Differences in Energy Expenditures and Growth Dilution Explain Higher PCB Concentrations in Male Summer Flounder

    PubMed Central

    Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O’Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

    2016-01-01

    Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes. PMID:26794728

  11. Differences in energy expenditures and growth dilution explain higher PCB concentrations in male summer flounder

    USGS Publications Warehouse

    Madenjian, Charles P.; Jensen, Olaf P.; Rediske, Richard R.; O'Keefe, James P.; Vastano, Anthony R.; Pothoven, Steven A.

    2016-01-01

    Comparison of polychlorinated biphenyl (PCB) concentrations between the sexes of mature fish may reveal important behavioral and physiological differences between the sexes. We determined whole-fish PCB concentrations in 23 female summer flounder Paralichthys dentatus and 27 male summer flounder from New Jersey coastal waters. To investigate the potential for differences in diet or habitat utilization between the sexes, carbon and nitrogen stable isotope ratios were also determined. In 5 of the 23 female summer flounder, PCB concentrations in the somatic tissue and ovaries were determined. In addition, we used bioenergetics modeling to assess the contribution of the growth dilution effect to the observed difference in PCB concentrations between the sexes. Whole-fish PCB concentrations for females and males averaged 87 and 124 ng/g, respectively; thus males were 43% higher in PCB concentration compared with females. Carbon and nitrogen stable isotope ratios did not significantly differ between the sexes, suggesting that diet composition and habitat utilization did not vary between the sexes. Based on PCB determinations in the somatic tissue and ovaries, we predicted that PCB concentration of females would increase by 0.6%, on average, immediately after spawning due to release of eggs. Thus, the change in PCB concentration due to release of eggs did not explain the higher PCB concentrations observed in males. Bioenergetics modeling results indicated that the growth dilution effect could account for males being 19% higher in PCB concentration compared with females. Thus, the bulk of the observed difference in PCB concentrations between the sexes was not explained by growth dilution. We concluded that a higher rate of energy expenditure in males, stemming from greater activity and a greater resting metabolic rate, was most likely the primary driver for the observed difference in PCB concentrations between the sexes.

  12. Isolation of Vibrio tapetis from two native fish species (Genypterus chilensis and Paralichthys adspersus) reared in Chile and description of Vibrio tapetis subsp. quintayensis subsp. nov.

    PubMed

    Levican, Arturo; Lasa, Aide; Irgang, Rute; Romalde, Jesús L; Poblete-Morales, Matías; Avendaño-Herrera, Ruben

    2017-04-01

    A group of seven Chilean isolates presumptively belonging to Vibrio tapetis was isolated from diseased fine flounders (Paralichthys adspersus) and red conger eel (Genypterus chilensis) experimentally reared in Quintay (Chile). All isolates were confirmed as members of V. tapetis on the basis of matrix-assisted laser desorption ionization time-of-flight MS, 16S rRNA gene sequencing, DNA-DNA hybridization values and G+C content. The ERIC-PCR and REP-PCR patterns were homogeneous among those isolates recovered from the same host (red conger or fine flounders), but distinct from the type strains V. tapetis subsp. tapetis CECT 4600T and V. tapetis subsp. britannicus CECT 8161T. On the basis of atpA, rpoA, rpoD, recA and pyrH gene sequence similarities (99.7-100 %) and clustering in the phylogenetic trees, the red conger isolates (Q20, Q047, Q48 and Q50) were confirmed as representing V. tapetis subsp. tapetis. However, they differed from V. tapetis subsp. tapetis CECT 4600T in their lipase, alpha quimiotripsin and non-acid phosphatase production. On the other hand, the fine flounder isolates (QL-9T, QL-35 and QL-41) showed rpoD, recA and pyrH gene sequence similarities ranging from 91.6 to 97.7 % with the type strains of the two V. tapetis subspecies (CECT 4600T and CECT 8161T) and consistently clustered together as an independent phylogenetic line within V. tapetis. Moreover, they could be differentiated phenotypically from strains CECT 4600T and CECT 8161T by nine and three different biochemical tests, respectively. In conclusion, the presence of V. tapetis in diseased red conger eel and fine flounder was demonstrated, extending the known host range and geographical location for this pathogen. Furthermore, this study demonstrates that the three isolates from fine flounder represent a novel subdivision within V. tapetis, for which the name V. tapetis subsp. quintayensis subsp. nov. is proposed and with QL-9T (=CECT 8851T=LMG 28759T) as the type strain. Although QL

  13. 78 FR 78786 - Fisheries of the Northeastern United States; 2014 Commercial Summer Flounder Quota Adjustments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... Northeastern United States; 2014 Commercial Summer Flounder Quota Adjustments AGENCY: National Marine Fisheries... 2014 commercial summer flounder state quotas. SUMMARY: NMFS is announcing the commercial summer flounder state quotas for fishing year 2014. The 2014 summer flounder specifications were established...

  14. Fishing mortality in North Carolina's southern flounder fishery: direct estimates of instantaneous fishing mortality from a tag return experiment

    USGS Publications Warehouse

    Smith, William E.; Scharf, Frederick S.; Hightower, Joseph E.

    2009-01-01

    Estimation of harvest rates is often a critical component of fishery stock assessment and management. These assessments are often based on catch-at-age data sets generated over many years, but estimates of instantaneous fishing mortality (F) can also be obtained from a shorter-term tag return study. We conducted a 2-year tag return experiment to generate direct estimates of F for southern flounder Paralichthys lethostigma in a North Carolina estuary. The southern flounder supports lucrative commercial and recreational fisheries within the state and has experienced heavy fishing pressure for more than a decade. During 2005 and 2006, fish were captured and tagged with the assistance of commercial harvesters in the New River estuary. Tag returns were used to generate monthly estimates of F, which demonstrated a clear seasonal pattern that was consistent between years. Several important assumptions of the tag return model were accounted for through the use of double-tagged individuals, the distribution of both high- and standard-reward tags, and the completion of an independent controlled experiment to evaluate mortality related to tagging. Annual estimates of F exceeded the short-term management target in both years. Residual patterns suggest that the estimates may actually have been biased low, possibly due to delayed mixing of tagged fish. Thus, despite recently amended fishery regulations, F in the North Carolina southern flounder gill-net fishery still has the potential to greatly exceed targeted levels, which may delay stock recovery. Tag return studies can provide reliable (and nearly real-time) information about F and natural mortality as long as the experimental design addresses specific assumptions related to tagging-induced mortality, tag shedding, and nonreporting of tags.

  15. 50 CFR 648.105 - Summer flounder recreational fishing season.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Summer flounder recreational fishing season. 648.105 Section 648.105 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Management Measures for the Summer Flounder Fisheries § 648.105 Summer flounder recreational fishing...

  16. 50 CFR 648.105 - Summer flounder recreational fishing season.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Summer flounder recreational fishing season. 648.105 Section 648.105 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Management Measures for the Summer Flounder Fisheries § 648.105 Summer flounder recreational fishing...

  17. 50 CFR 648.105 - Summer flounder recreational fishing season.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Summer flounder recreational fishing season. 648.105 Section 648.105 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL... Management Measures for the Summer Flounder Fisheries § 648.105 Summer flounder recreational fishing...

  18. A multiple endpoint analysis of the effects of chronic exposure to sediment contaminated with Deepwater Horizon oil on juvenile Southern flounder and their associated microbiomes.

    PubMed

    Brown-Peterson, Nancy J; Krasnec, Michelle; Takeshita, Ryan; Ryan, Caitlin N; Griffitt, Kimberly J; Lay, Claire; Mayer, Gregory D; Bayha, Keith M; Hawkins, William E; Lipton, Ian; Morris, Jeffrey; Griffitt, Robert J

    2015-08-01

    Exposure to oiled sediments can negatively impact the health of fish species. Here, we examine the effects of chronic exposure of juvenile southern flounder, Paralichthys lethostigma, to a sediment-oil mixture. Oil:sediment mixtures are persistent over time and can become bioavailable following sediment perturbation or resuspension. Juvenile flounder were exposed for 32 days under controlled laboratory conditions to five concentrations of naturally weathered Macondo MC252 oil mixed into uncontaminated, field-collected sediments. The percent composition of individual polycyclic aromatic hydrocarbons (PAHs) of the weathered oil did not change after mixing with the sediment. Spiked exposure sediments contained 0.04-395mg/kg tPAH50 (sum of 50 individual PAH concentration measurements). Mortality increased with both exposure duration and concentration of sediment-associated PAHs, and flounder exposed to concentrations above 8mg/kg tPAH50 showed significantly reduced growth over the course of the experiment. Evident histopathologic changes were observed in liver and gill tissues of fish exposed to more than 8mg/kg tPAH50. All fish at these concentrations showed hepatic intravascular congestion, macrovesicular hepatic vacoulation, telangiectasia of secondary lamellae, and lamellar epithelial proliferation in gill tissues. Dose-dependent upregulation of Cyp1a expression in liver tissues was observed. Taxonomic analysis of gill and intestinal commensal bacterial assemblages showed that exposure to oiled sediments led to distinct shifts in commensal bacterial population structures. These data show that chronic exposure to environmentally-relevant concentrations of oiled sediments produces adverse effects in flounder at multiple biological levels.

  19. Habitat Suitability Index Models: Southern and gulf flounders

    USGS Publications Warehouse

    Enge, Kevin M.; Mulholland, Rosemarie

    1985-01-01

    Both the southern and gulf flounders (paralichthrS lethostigma, f. albi~utta) are important commercial and recreationa species. Catch statlstics for flounder do not differentiate between species; however, southern flounders are more common than gulf flounders except on the gulf coast of Florida (Topp and Hoff 1972). The commercial fishery consists of incidental catches by shrimp trawlers. A total of 853,162 kg (1,880,900 lb) of unclassified flounder worth $572,142 was caught from the Gulf of Mexico in 1976 (U.S. Dep. Commerce 1980). The sport fishery consists of both hook-and-line fishing and gigging.

  20. 75 FR 52890 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... United States; Summer Flounder Fishery; Commercial Quota Harvested for the Commonwealth of Massachusetts...), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2010 summer flounder commercial... Federal fisheries permit for the summer flounder fishery may not land summer flounder in Massachusetts...

  1. 77 FR 75569 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the State of New Jersey...), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2012 summer flounder commercial... fisheries permit for the summer flounder fishery may not land summer flounder in New Jersey for...

  2. 77 FR 52262 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the Commonwealth of... (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2012 summer flounder... commercial Federal fisheries permit for the summer flounder fishery may not land summer flounder...

  3. 78 FR 59626 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-27

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the State of New York...), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2013 summer flounder commercial... fisheries permit for the summer flounder fishery may not land summer flounder in New York for the...

  4. 78 FR 51096 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the Commonwealth of... (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2013 summer flounder... commercial Federal fisheries permit for the summer flounder fishery may not land summer flounder...

  5. 77 FR 64239 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the State of New York...), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2012 summer flounder commercial... fisheries permit for the summer flounder fishery may not land summer flounder in New York for the...

  6. 78 FR 70890 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-27

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the State of New Jersey...), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2013 summer flounder commercial... fisheries permit for the summer flounder fishery may not land summer flounder in New Jersey for...

  7. 78 FR 72585 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-03

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested for the Commonwealth of... (NOAA), Commerce. ACTION: Temporary rule; closure. SUMMARY: NMFS announces that the 2013 summer flounder... Federal fisheries ] permit for the summer flounder fishery may not land summer flounder in Virginia...

  8. Finding Flounders: Outsmarting the Art of Camouflage

    ScienceCinema

    None

    2016-11-30

    At Los Alamos National Laboratory, we study camouflage in nature to learn how we can identify things trying to disguise themselves. We do that by looking at marine organisms that are exceptionally good at the art of blending in: flounders, skates, cuttlefish and octopi. The goal of this work was to develop efficient automated methods for detecting and analyzing features in remote sensing imagery for national security and intelligence applications.

  9. Finding Flounders: Outsmarting the Art of Camouflage

    SciTech Connect

    2016-11-01

    At Los Alamos National Laboratory, we study camouflage in nature to learn how we can identify things trying to disguise themselves. We do that by looking at marine organisms that are exceptionally good at the art of blending in: flounders, skates, cuttlefish and octopi. The goal of this work was to develop efficient automated methods for detecting and analyzing features in remote sensing imagery for national security and intelligence applications.

  10. Effect of dietary supplementation with Suaeda maritima on blood physiology, innate immune response, and disease resistance in olive flounder against Miamiensis avidus.

    PubMed

    Harikrishnan, Ramasamy; Kim, Ju-Sang; Kim, Man-Chul; Dharaneedharan, Subramanian; Kim, Dong-Hwi; Hong, Seung-Hyun; Song, Chang-Young; Balasundaram, Chellam; Heo, Moon-Soo

    2012-06-01

    The effect of Suaeda maritima enriched diet on blood physiology, innate immune response, and disease resistance in olive flounder Paralichythys olivaceus against Miamiensis avidus on weeks 1, 2, and 4 was investigated. Feeding with any enriched diet and then challenging with M. avidus significantly increased white blood cells (WBC) on weeks 2 and 4; the red blood cells (RBC) significantly increased with 0.1% and 1.0% enriched diets on week 4. The hemoglobin (Hb) and hematocrit (Ht) levels significantly increased when fed with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The mean corpuscular volume (MCV) did not significantly vary with any diet and time; however the mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) significantly increased with 0.1% and 1.0% supplementation diets on weeks 2 and 4. The leukocytes such as lymphocytes (Lym), monocytes (Mon), neutrophils (Neu) and biochemical parameters such as total protein (TP), glucose (GLU), and calcium (CAL) levels significantly increased in 0.1% and 1.0% supplementation diet fed groups on weeks 2 and 4. The serum lysozyme activity was significantly enhanced in 0.1% and 1.0% supplementation diet fed groups from weeks 1 to 4 when compared to the control (0% herbal extract enriched diet). The scuticocidal activity and respiratory burst activity were significantly enhanced when fish were fed with 0.1% and 1.0% supplementation diets from weeks 2 and 4. The protective effect in terms of cumulative mortality (50% and 40%) was low in groups on being fed with 0.1% and 1.0% supplemented diet. Therefore the present study suggested that 0.1% and 1.0% S. maritime-supplemented diets protect the hematological and biochemical parameters, improving the innate immunity, affording protection disease from M. avidus infection in olive flounder.

  11. 77 FR 76942 - 2013-2014 Summer Flounder and Scup Specifications; 2013 Black Sea Bass Specifications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... and Scup Specifications; 2013 Black Sea Bass Specifications; Preliminary 2013 Quota Adjustments; 2013... the 2013 summer flounder, scup, and black sea bass fisheries, as well as the 2014 summer flounder and... necessary to comply with regulations implementing the Summer Flounder, Scup, and Black Sea Bass...

  12. 78 FR 76766 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Harvested...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ...NMFS announces that the 2013 summer flounder commercial quota allocated to the State of New Jersey has been harvested. Vessels issued a commercial Federal fisheries permit for the summer flounder fishery may not land summer flounder in New Jersey for the remainder of calendar year 2013, unless additional quota becomes available through a transfer from another state. Regulations governing the......

  13. 75 FR 82295 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. In addition, the State of Maine is transferring a portion of its 2010 commercial summer flounder quota to the State of Rhode Island. By...

  14. 75 FR 2820 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-19

    ... United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service (NMFS... summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  15. 75 FR 22025 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-27

    ... United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service (NMFS... summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  16. 76 FR 81851 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and...-9224. SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50...

  17. 77 FR 14481 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-12

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  18. 76 FR 19276 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-07

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of ] Virginia. Vessels were authorized by Virginia to land summer flounder under safe harbor provisions, thereby requiring a quota transfer to account for...

  19. 78 FR 66857 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-07

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... summer flounder quota to the State of Connecticut. NMFS is adjusting the quotas and announcing the.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are in 50 CFR part 648, and...

  20. 50 CFR 648.107 - Conservation equivalent measures for the summer flounder fishery.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... summer flounder fishery. 648.107 Section 648.107 Wildlife and Fisheries FISHERY CONSERVATION AND... NORTHEASTERN UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.107 Conservation equivalent measures for the summer flounder fishery. (a) The Regional Administrator has determined that...

  1. 75 FR 76925 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  2. 77 FR 69567 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the State of Rhode Island. NMFS is adjusting the quotas and announcing.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are in 50 CFR part 648, and...

  3. 78 FR 9849 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-12

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... of its 2012 commercial summer flounder quota to the Commonwealth of Virginia. NMFS is adjusting the... INFORMATION: Regulations governing the summer flounder fishery are in 50 CFR part 648, and require...

  4. 78 FR 25003 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-29

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia and to the State of Rhode Island; and that the Commonwealth of Virginia is transferring a portion of its 2013 commercial summer flounder quota...

  5. 76 FR 81851 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... summer flounder quota to the State of Rhode Island. By this action, NMFS adjusts the quotas and announces...-9224. SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50...

  6. 77 FR 19951 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. The State of North Carolina is also retroactively transferring a portion of its 2011 commercial summer flounder quota to the Commonwealth...

  7. 75 FR 30739 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service (NMFS... summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  8. 78 FR 77005 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... both transferring a portion of their 2013 commercial summer flounder quotas to the Commonwealth of... summer flounder fishery are in 50 CFR part 648, and require annual specification of a commercial...

  9. 75 FR 4490 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-28

    ... United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service (NMFS... summer flounder quota to the Commonwealth of Virginia. By this action, NMFS adjusts the quotas and.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are found at 50 CFR part 648....

  10. 76 FR 23206 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-26

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. Vessels from North Carolina were authorized by Virginia to land summer flounder under safe harbor provisions, thereby requiring a quota...

  11. 76 FR 17032 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-28

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... and 2011 commercial summer flounder quotas to the Commonwealth of Virginia. Vessels were authorized by Virginia to land summer flounder under safe harbor provisions, thereby requiring a quota transfer...

  12. 78 FR 33 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia, the State of North Carolina is transferring a portion of its 2012 commercial summer flounder quota to the State of Connecticut, and...

  13. 77 FR 25103 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-27

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia. NMFS is adjusting the quotas and announcing.... SUPPLEMENTARY INFORMATION: Regulations governing the summer flounder fishery are in 50 CFR part 648, and...

  14. 50 CFR 648.110 - Summer flounder framework adjustments to management measures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Summer flounder framework adjustments to... UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.110 Summer flounder framework... instead of a framework adjustment. (2) MAFMC recommendation. After developing management actions...

  15. 50 CFR 648.110 - Summer flounder framework adjustments to management measures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Summer flounder framework adjustments to... UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.110 Summer flounder framework... are otherwise introducing new concepts may require an amendment of the FMP instead of a...

  16. 50 CFR 648.110 - Summer flounder framework adjustments to management measures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Summer flounder framework adjustments to... UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.110 Summer flounder framework... are otherwise introducing new concepts may require an amendment of the FMP instead of a...

  17. 50 CFR 648.110 - Summer flounder framework adjustments to management measures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Summer flounder framework adjustments to... UNITED STATES Management Measures for the Summer Flounder Fisheries § 648.110 Summer flounder framework... are otherwise introducing new concepts may require an amendment of the FMP instead of a...

  18. Use of a Marine Vertebrate, the Flounder, in the Physiology Teaching Laboratory

    ERIC Educational Resources Information Center

    Bruce, David S.; Linden, Donald G.

    1973-01-01

    Describes two experiments in physiology using a readily available marine vertebrate, the flounder. Representative results are presented from experiments which measure the effect of excess potassium on the flounder EKG, and the effect of temperature on heart rate of the starry flounder. (JR)

  19. 75 FR 70192 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... United States; Summer Flounder, Scup, and Black Sea Bass Fisheries; 2011 Summer Flounder, Scup, and Black... specifications; request for comments. SUMMARY: NMFS proposes specifications for the 2011 summer flounder, scup...-Aside (RSA) program. The implementing regulations for the Summer Flounder, Scup, and Black Sea...

  20. 77 FR 68723 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ... Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries; 2013-2014 Summer Flounder... summer flounder, scup, and black sea bass fisheries, and the 2014 summer flounder and scup fisheries, and... Fishery Management Council's Research Set-Aside Program. The implementing regulations for the...

  1. 76 FR 53831 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... United States; Summer Flounder, Scup, and Black Sea Bass Fisheries; 2011 Summer Flounder, Scup, and Black... December 28, 2010, NMFS published in the Federal Register the final rule to implement the 2011 summer flounder, scup, and black sea bass specifications, which established commercial summer flounder...

  2. First isolation of Pseudocohnilembus persalinus (Ciliophora: Scuticociliatida) from freshwater-reared rainbow trout, Oncorhynchus mykiss.

    PubMed

    Jones, Simon R M; Prosperi-Porta, Gina; LaPatra, Scott E

    2010-10-01

    Ciliated protists were isolated from the ovarian fluid of apparently healthy adult rainbow trout (Oncorhynchus mykiss) maintained in freshwater. The organism was identified as Pseudocohnilembus persalinus based on morphometric and morphological analysis of silver-stained specimens obtained from culture and on analysis of ribosomal RNA gene sequences. The cytochrome c oxidase subunit 1 gene sequence of this organism also was characterized. This ciliate has been reported previously as free living only in saline environments and as an endosymbiont in a marine teleost, the olive flounder (Paralichthys olivaceus). A cyst-like stage may have facilitated the novel occurrence of this organism as an endosymbiont in rainbow trout.

  3. Windowpane flounder (Scophthalmus aquosus) and winter flounder (Pseudopleuronectes americanus) responses to cold temperature extremes in a Northwest Atlantic estuary

    NASA Astrophysics Data System (ADS)

    Wilber, Dara H.; Clarke, Douglas G.; Alcoba, Catherine M.; Gallo, Jenine

    2016-01-01

    The effect of climate variability on flatfish includes not only the effects of warming on sensitive life history stages, but also impacts from more frequent or unseasonal extreme cold temperatures. Cold weather events can affect the overwintering capabilities of flatfish near their low temperature range limits. We examined the responses of two flatfish species, the thin-bodied windowpane (Scophthalmus aquosus) and cold-tolerant winter flounder (Pseudopleuronectes americanus), to variable winter temperatures in a Northwest Atlantic estuary using abundance and size data collected during a monitoring study, the Aquatic Biological Survey, conducted from 2002 to 2010. Winter and spring abundances of small (50 to 120 mm total length) juvenile windowpane were positively correlated with adult densities (spawning stock) and fall temperatures (thermal conditions experienced during post-settlement development for the fall-spawned cohort) of the previous year. Windowpane abundances in the estuary were significantly reduced and the smallest size class was nearly absent after several consecutive years with cold (minimum temperatures < 1 °C) winters. Interannual variation in winter flounder abundances was unrelated to the severity of winter temperatures. A Paulik diagram illustrates strong positive correlations between annual abundances of sequential winter flounder life history stages (egg, larval, Age-1 juvenile, and adult male) within the estuary, reflecting residency within the estuary through their first year of life. Temperature variables representing conditions during winter flounder larval and post-settlement development were not significant factors in multiple regression models exploring factors that affect juvenile abundances. Likewise, densities of predators known to consume winter flounder eggs and/or post-settlement juveniles were not significantly related to interannual variation in winter flounder juvenile abundances. Colder estuarine temperatures through the

  4. Taxonomy of the early life stages of arrowtooth flounder (Atheresthes stomias) and Kamchatka flounder (A. evermanni) in the eastern Bering Sea, with notes on distribution and condition

    NASA Astrophysics Data System (ADS)

    De Forest, Lisa; Duffy-Anderson, J. T.; Heintz, R. A.; Matarese, A. C.; Siddon, E. C.; Smart, T. I.; Spies, I. B.

    2014-11-01

    Arrowtooth flounder (Atheresthes stomias) and Kamchatka flounder (A. evermanni) are closely related flatfish species that co-occur in the eastern Bering Sea. As adults, arrowtooth flounder can be distinguished from Kamchatka flounder; however, larvae and early juveniles can only be indentified to the genus level due to morphological similarities. This has precluded studies of ecology for the early life stages of both species in the eastern Bering Sea. In this study, we developed a genetic technique to identify the larvae and early juveniles of the two species using mtDNA cytochrome oxidase subunit I (COI). Genetically identified specimens were then examined to determine a visual identification method based on pigment patterns and morphology. Specimens 6.0-12.0 mm SL and≥18.0 mm SL can be identified to the species level, but species identification of individuals 12.1-17.9 mm SL by visual means alone remains elusive. The distribution of larvae (<25.0 mm SL) of both arrowtooth flounder and Kamchatka flounder is similar in the eastern Bering Sea; however, juvenile (≥25.0 mm SL) Kamchatka flounder occur closer to the shelf break and in deeper water than juvenile arrowtooth flounder. Condition was determined for larvae and juveniles of each species by analyzing lipid content (%) and energy density (kJ/g dry mass). Kamchatka flounder larvae on average had higher lipid content than arrowtooth flounder larvae, but were also larger on average than arrowtooth flounder larvae in the summer. When corrected for length, both species had similar lipid content in the larval and juvenile stages.

  5. RELATIONSHIPS BETWEEN HABITAT QUALITY AND DENSITY OF JUVENILE WINTER FLOUNDER

    EPA Science Inventory

    We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat. The YSI sonde measured temperature, salinity, dissolve...

  6. 50 CFR 648.108 - Summer flounder gear restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Otter trawlers whose owners are issued a summer flounder permit and that land or possess 100 lb (45.4 kg... a review of sea sampling data, that vessels fishing under the exemption are discarding more than 10.... (ii) (2) Vessels fishing with a two-seam otter trawl fly net with the following...

  7. 50 CFR 648.108 - Summer flounder gear restrictions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) Otter trawlers whose owners are issued a summer flounder permit and that land or possess 100 lb (45.4 kg... a review of sea sampling data, that vessels fishing under the exemption are discarding more than 10.... (ii) (2) Vessels fishing with a two-seam otter trawl fly net with the following...

  8. 50 CFR 648.108 - Summer flounder gear restrictions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Otter trawlers whose owners are issued a summer flounder permit and that land or possess 100 lb (45.4 kg... a review of sea sampling data, that vessels fishing under the exemption are discarding more than 10.... (ii) (2) Vessels fishing with a two-seam otter trawl fly net with the following...

  9. 50 CFR Figure 10 to Part 223 - Flounder TED

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Flounder TED 10 Figure 10 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 10 Figure 10...

  10. 50 CFR Figure 10 to Part 223 - Flounder TED

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Flounder TED 10 Figure 10 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 10 Figure 10...

  11. 50 CFR Figure 10 to Part 223 - Flounder TED

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Flounder TED 10 Figure 10 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 10 Figure 10...

  12. 50 CFR Figure 11 to Part 223 - Modified Flounder TED

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Modified Flounder TED 11 Figure 11 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig....

  13. 50 CFR Figure 11 to Part 223 - Modified Flounder TED

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Modified Flounder TED 11 Figure 11 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig....

  14. 50 CFR Figure 11 to Part 223 - Modified Flounder TED

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Modified Flounder TED 11 Figure 11 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig....

  15. 50 CFR Figure 10 to Part 223 - Flounder TED

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Flounder TED 10 Figure 10 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 10 Figure 10...

  16. 50 CFR Figure 10 to Part 223 - Flounder TED

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Flounder TED 10 Figure 10 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES Pt. 223, Fig. 10 Figure 10...

  17. Complete mitochondrial genome of the urohaze-goby Glossogobius olivaceus (Perciformes, Gobiidae) and structure comparison of light strand replication origin in Gobioidei.

    PubMed

    Sun, Yuena; Wei, Tao; Jin, Xiaoxiao; Qin, Yu; Xu, Tianjun

    2015-01-01

    The genome of Glossogobius olivaceus (G. olivaceus) was 16,568 bp in length with a standard set of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs) and 2 non-coding region (the control region and origin of the light strand replication). The conserved motif 5'-GCCGG-3' was determined in the origin of light strand replication of G. olivaceus. The G. olivaceus mitogenome base composition was: T 25.65%, C 29.82% A 27.17% and G 17.36%, with a slight A+T bias of 52.82%, which was similar to most of the vertebrate mitogenomes. The mitochondrial genome of G. olivaceus had common features regarding gene arrangement and tRNA structures compared with those of other bony fishes.

  18. Pilot attempt to grow winter flounders commercially. Completion report 15 Feb 77-30 Jun 80

    SciTech Connect

    Sawyer, P.J.; Hoornbeek, F.K.

    1980-09-01

    The first part of this report contains the details and results of laboratory efforts to raise flounders through the early developmental stages including metamorphosis. The second part reports the efforts to grow out newly metamorphosed flounders to commercial size. In order to produce marketable sized winter flounders in heated water, it will be necessary to assure availability of brood stock and an abundance of live food both prior and subsequent to metamorphosis.

  19. Biochemical characteristics of four marine fish skins in Korea.

    PubMed

    Cho, Jae-Kwon; Jin, Young-Guk; Rha, Sung-Ju; Kim, Seon-Jae; Hwang, Jae-Ho

    2014-09-15

    In this study, we investigated the biochemical characteristics of the fish skins of four industrial species: olive flounder (Paralichthys olivaceus), black rockfish (Sebastes schlegeli), sea bass (Lateolabrax maculatus) and red sea bream (Pagrus major). There is high domestic demand in Korea for farming of these fish for human consumption. Crude protein contents in the skin of these fish ranged from 73% to 94% by dry weight; this was in part due to a high content of the structural protein, collagen. Among the four species, olive flounder had the thickest dermal and epidermal layers in the dorsal skin. This species was also associated with the highest extraction ratio of acid-soluble collagen. We also examined whether fish skin could be a cost-effective alternative to current fish meal sources. Our analysis indicates that, when supplemented with additional fish oils and essential amino acids, fish skin is a viable alternative for fish meal formulations.

  20. Adaptive differences in gene expression in European flounder (Platichthys flesus).

    PubMed

    Larsen, Peter F; Nielsen, Einar E; Williams, Timothy D; Hemmer-Hansen, Jakob; Chipman, James K; Kruhøffer, Mogens; Grønkjaer, Peter; George, Stephen G; Dyrskjøt, Lars; Loeschcke, Volker

    2007-11-01

    Population structure was previously believed to be very limited or absent in classical marine fishes, but recently, evidence of weakly differentiated local populations has been accumulating using noncoding microsatellite markers. However, the evolutionary significance of such minute genetic differences remains unknown. Therefore, in order to elucidate the relationship between genetic markers and adaptive divergence among populations of marine fishes, we combined cDNA microarray and microsatellite analysis in European flounders (Platichthys flesus). We demonstrate that despite extremely low levels of neutral genetic divergence, a high number of genes were significantly differentially expressed between North Sea and Baltic Sea flounders maintained in a long-term reciprocal transplantation experiment mimicking natural salinities. Several of the differentially regulated genes could be directly linked to fitness traits. These findings demonstrate that flounders, despite little neutral genetic divergence between populations, are differently adapted to local environmental conditions and imply that adaptation in gene expression could be common in other marine organisms with similar low levels of population subdivision.

  1. 78 FR 20037 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia and to the State of New Jersey. NMFS is... Management Specialist, 978-281-9224. SUPPLEMENTARY INFORMATION: Regulations governing the summer...

  2. 78 FR 75267 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Available...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Available for the State of New Jersey...), Commerce. ACTION: Temporary rule. SUMMARY: NMFS announces that the 2013 summer flounder commercial fishery... harvest the available quota. Vessels issued a commercial Federal fisheries permit for the summer...

  3. 78 FR 13812 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... commercial summer flounder quota to the Commonwealth of Virginia and to the State of Rhode Island. NMFS is... Management Specialist, 978-281-9224. SUPPLEMENTARY INFORMATION: Regulations governing the summer...

  4. 77 FR 74390 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Commercial Quota Available...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ... Northeastern United States; Summer Flounder Fishery; Commercial Quota Available for the State of New York To... Administration (NOAA), Commerce. ACTION: Temporary rule. SUMMARY: NMFS announces that the 2012 summer flounder... fully harvest the available quota. Vessels issued a commercial Federal fisheries permit for the...

  5. 76 FR 29670 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... Atmospheric Administration 50 CFR Part 648 RIN 0648-XA403 Fisheries of the Northeastern United States; Summer... that the State of North Carolina is transferring a portion of its 2011 commercial summer flounder quota... of its 2011 commercial summer flounder quota to New Jersey. Vessels from North Carolina...

  6. 50 CFR Figure 6 to Part 223 - TED Extension in Summer Flounder Trawl

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false TED Extension in Summer Flounder Trawl 6 Figure 6 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND.... 223, Fig. 6 Figure 6 to Part 223—TED Extension in Summer Flounder Trawl ER15OC99.001...

  7. 77 FR 73556 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ... States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service (NMFS.... SUMMARY: NMFS announces that the State of Maine is transferring a portion of its 2012 commercial summer... INFORMATION: Regulations governing the summer flounder fishery are in 50 CFR part 648, and require...

  8. 77 FR 5414 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-03

    ... Northeastern United States; Summer Flounder Fishery; Quota Transfer AGENCY: National Marine Fisheries Service... of its 2011 commercial summer flounder quota to the Commonwealth of Virginia. By this action, NMFS... Management Specialist, (978) 281-9224. SUPPLEMENTARY INFORMATION: Regulations governing the summer...

  9. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 12 2014-10-01 2014-10-01 false Yellowtail flounder sub-ACLs and AMs for...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial... Georges Bank and Southern New England/Mid-Atlantic stocks of yellowtail flounder. The sub-ACLs for...

  10. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 12 2013-10-01 2013-10-01 false Yellowtail flounder sub-ACLs and AMs for...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial... Georges Bank and Southern New England/Mid-Atlantic stocks of yellowtail flounder. The sub-ACLs for...

  11. Habitat selection of stone and starry flounders in an estuary in relation to feeding and survival

    NASA Astrophysics Data System (ADS)

    Tomiyama, Takeshi; Omori, Michio

    2008-09-01

    Juveniles of both stone flounder Platichthys bicoloratus and starry flounder Platichthys stellatus utilize estuaries as nursery grounds. To understand their habitat selection and the functions of habitats such as food supply, we defined the seasonal distribution of recently settled fish of these species in shallow nursery areas and investigated their feeding habits in the Natori River estuary, Japan. Distribution of stone flounder was limited to the lower estuary (<3 km upriver from the mouth) and stone flounder were most abundant near the mouth. Recently settled starry flounder were first detected further upstream in areas characterized by low salinity <10 and by the absence of the predatory sand shrimp Crangon uritai. Early juvenile stone and starry flounders consumed mainly siphons of the bivalve Nuttallia olivacea and the mysid Neomysis awatschensis, respectively; however, 1- and 2-yr-old fish of both stone and starry flounders fed mainly on the bivalve siphons. These results indicate that habitat selections of juvenile stone and starry flounders enable utilization of preferred prey and predator avoidance, respectively, and that non-overlap of these species' habitats results in avoidance of inter-specific competition for food between these two species.

  12. General condition biomarkers in relation to contaminant burden in European flounder (Platichthys flesus).

    PubMed

    Kleinkauf, Anne; Connor, Leslie; Swarbreck, David; Levene, Carolyn; Walker, Peter; Johnson, Paul J; Leah, Richard T

    2004-07-01

    In respect to the differences found for vitellogenin (VTG) expression in male and immature flounder, general biological aspects and a set of chemical residues in the liver were compared between flounder from the Mersey and Dee estuaries (UK). Except for alpha-HCH, all pollutant chemicals analysed in flounder liver differed highly significantly between Mersey and Dee fish. Overall, the higher liver contaminant concentrations were found in VTG-induced Mersey flounder. The biomarkers studied were not found to indicate significant differences between Mersey and Dee fish. However, when all of the minor differences are taken into consideration, it appears that the slightly lower growth rates after age 2 in Mersey flounder, lower gonadosomatic index in both mature male and female animals, less precise seasonal patterns of condition factor (CF), hepatosomatic index and gonadosomatic index, and lower CF in immature Mersey fish may well be signs of a contaminant-affected Mersey population.

  13. Liver lesions in winter flounder (Pseudopleuronectes americanus) from Jamaica Bay, New York: Indications of environmental degradation

    USGS Publications Warehouse

    Augspurger, T.P.; Herman, R.L.; Tanacredi, J.T.; Hatfield, J.S.

    1994-01-01

    Liver sections of winter flounder (Pseudopleuronectes americanus) collected from Jamaica Bay and Shinnecock Bay, New York, in 1989, were examined microscopically to determine the pervasiveness of liver lesions observed previously in Jamaica Bay winter flounder. Neoplastic lesions were not detected in fish from Jamaica Bay or the Shinnecock Bay reference site. Twenty-two percent of Jamaica Bay winter flounder examined (n = 103) had unusual vacuolization of hepatocytes and biliary pre-ductal and ductal cells (referred to hereafter as the vacuolated cell lesion). The lesion, identical to that found in 25% of Jamaica Bay winter flounder examined in 1988, has previously been identified in fishes taken from highly polluted regions of the Atlantic coast (e.g., Boston Harbor, Massachusetts, and Black Rock Harbor, Connecticut). Prevalence of the vacuolated cell lesion in winter flounder from Jamaica Bay was significantly greater (p < 0.0001) than in 102 specimens collected from Shinnecock Bay. Current scientific literature indicates vacuolated hepatocytes and cholangiocytes are chronically injured and that the extent of their deformity is consistent with the action of a hepatotoxicant. The high prevalence of vacuolated hepatocytes in Jamaica Bay winter flounder and absence of the lesion in flounder from reference sites strongly supports the hypothesis that this impairment is a manifestation of a toxic condition in at least some portions of Jamaica Bay.

  14. Changeable camouflage: how well can flounder resemble the colour and spatial scale of substrates in their natural habitats?

    PubMed Central

    Akkaynak, Derya; Siemann, Liese A.; Barbosa, Alexandra

    2017-01-01

    Flounder change colour and pattern for camouflage. We used a spectrometer to measure reflectance spectra and a digital camera to capture body patterns of two flounder species camouflaged on four natural backgrounds of different spatial scale (sand, small gravel, large gravel and rocks). We quantified the degree of spectral match between flounder and background relative to the situation of perfect camouflage in which flounder and background were assumed to have identical spectral distribution. Computations were carried out for three biologically relevant observers: monochromatic squid, dichromatic crab and trichromatic guitarfish. Our computations present a new approach to analysing datasets with multiple spectra that have large variance. Furthermore, to investigate the spatial match between flounder and background, images of flounder patterns were analysed using a custom program originally developed to study cuttlefish camouflage. Our results show that all flounder and background spectra fall within the same colour gamut and that, in terms of different observer visual systems, flounder matched most substrates in luminance and colour contrast. Flounder matched the spatial scales of all substrates except for rocks. We discuss findings in terms of flounder biology; furthermore, we discuss our methodology in light of hyperspectral technologies that combine high-resolution spectral and spatial imaging.

  15. Renal morphology of the euryhaline flounder (Platichthys flesus): distribution of arginine vasotocin receptor.

    PubMed

    Weybourne, E; Warne, J M; Hentschel, H; Elger, M; Balment, R J

    2005-04-01

    The current study characterized tubular segmentation of the European flounder nephron and localized the vasotocin receptor expression by immunohistochemistry. Flounder nephron was shown to comprise a prominent renal corpuscle, short neck segment, proximal tubule I, proximal tubule II, collecting tubule, and collecting duct. Using specific antibodies raised against flounder vasotocin receptor, specific V(1) receptor staining was detected within the glomeruli, the endothelial surface of the afferent and efferent arterioles, and the capillaries surrounding the collecting duct system. Immunostaining for the receptor was exclusively vascular and there did not appear to be a tubular component.

  16. Early growth and development of reciprocal hybrids of the starry flounder Platichthys stellatus and stone flounder Kareius bicoloratus.

    PubMed

    Yamashita, Y T; Aritaki, M; Kurita, Y; Tanaka, M

    2014-05-01

    Larval growth and development of hybrid flounder were observed and compared with those of their parent species. The reciprocal hybrids of female starry flounder Platichthys stellatus and male stone flounder Kareius bicoloratus (hybrid Sb) and of female K. bicoloratus and male P. stellatus (hybrid Bs) both survived and grew to juveniles. Development was divided into nine stages (A-I). Many of the hybrids' traits were identical and intermediate to those of their parents. The position of the eye, however, was primarily sinistral in both hybrids (80% in Sb and 76% in Bs), a trait possessed by P. stellatus (80%) in the western Pacific Ocean. The daily growth rates of the larvae were similar. In the parent species, development was more rapid in P. stellatus than in K. bicoloratus whereas rate of development was intermediate in both Sb and Bs hybrids. The size at settlement [standard length (LS ) at stage H (mean ± s.d.)] was 9·82 ± 1·47 mm for the hybrid Sb and 9·99 ± 0·90 mm for the hybrid Bs, while the minimum age at metamorphosis (initial age at stage H) was 29 days after hatching (DAH) in both hybrids. In comparison, LS at settlement in parent species was 6·43 ± 0·25 mm for P. stellatus and 12·87 ± 1·29 mm for K. bicoloratus. Minimum age at metamorphosis for the parents was 23 DAH at stage G in P. stellatus and 34 DAH at stage H in K. bicoloratus. Thus, the timing of settlement of hybrids was different from that of their parent species. These traits may occur with high frequency in a natural habitat.

  17. Temporal trends in nitrogen isotope ratios of winter flounder collected from Rhode Island coastal systems

    EPA Science Inventory

    Nitrogen isotope ratios (15N) were measured in muscle tissue of juvenile winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems along the coast of Rhode Island, USA, including Narragansett Bay, Narrow River and three coastal lagoons. Fish collect...

  18. Inactivation of Kudoa septempunctata in olive flounder meat by liquid freezing.

    PubMed

    Ohnishi, Takahiro; Akuzawa, Sayuri; Furusawa, Hiroko; Yoshinari, Tomoya; Kamata, Yoichi; Sugita-Konishi, Yoshiko

    2014-01-01

    Kudoa septempunctata in olive flounder meat was inactivated using 3 distinct freezing methods:liquid freezing for 5 min, air blast freezing at -30℃ for 5 h, and -80℃ for 1 h. The fracture curve of olive flounder meat subjected to liquid freezing resembled that of meat stored at 4℃, indicating that the structure of olive flounder muscle was well preserved. In contrast, air blast freezing induced the disappearance of the fracture point in the fracture curve, indicating that there was deterioration in the meat quality. Liquid freezing preserved the transparency of olive flounder meat to the same degree as that of meat stored at 4°C. However, air blast freezing induced meat cloudiness. These results indicate that liquid freezing can be used for K. septempunctata inactivation without affecting the meat quality.

  19. 78 FR 76765 - Fisheries of the Northeastern United States; Summer Flounder Fishery; Quota Transfer

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ...NMFS announces that the State of Maryland is transferring a portion of its 2013 commercial summer flounder quota to the State of Connecticut. NMFS is adjusting the quotas and announcing the revised commercial quota for each state...

  20. Ultrastructure of the olfactory epithelium in a flatfish, barfin flounder (Verasper moseri).

    PubMed

    Nakamuta, Shoko; Nakamuta, Nobuaki; Taniguchi, Kazuyuki

    2010-06-01

    In this study, we examined the olfactory epithelium (OE) of the barfin flounder by transmission electron microscopy. As in the case of the ordinary teleost, the OE of the barfin flounder had 3 types of olfactory receptor cells (ciliated olfactory receptor cell, microvillous olfactory receptor cell and crypt cell), 3 types of supporting cells (ciliated, microvillous and crypt supporting cells) and basal cells. Each type of OE cells in the barfin flounder had similar ultrastructure to that of the ordinary teleost. Crypt cell is the third type of olfactory receptor cell unique to fish, whose function is unclear. The barfin flounder may be a suitable material to study crypt cells because it has relatively abundant crypt cells in the OE.

  1. Seasonality of metazoan ectoparasites in marine European flounder Platichthys flesus (Teleostei: Pleuronectidae).

    PubMed

    Cavaleiro, F I; Santos, M J

    2009-07-01

    Seasonal occurrence of metazoan ectoparasites is described for the first time in marine European flounder, Platichthys flesus (L.). The parasitofauna, in this study monitored during 1 year, was found to be similar to that previously recorded for flounder. Moreover, specimens of Caligus sp. Müller, 1785 and Lepeophtheirus pectoralis (Copepoda: Caligidae), Acanthochondria cornuta (Copepoda: Chondracanthidae), Holobomolochus confusus (Copepoda: Bomolochidae) and Nerocila orbignyi (Isopoda: Cymothoidae), and also, a praniza larva (Isopoda: Gnathiidae), were isolated. From these, L. pectoralis and A. cornuta were the dominant parasites in all samples of flounder, while Caligus sp., H. confusus, N. orbignyi and the gnathiid praniza seemed to infect the flounder only occasionally. As far as the seasonality of infections is concerned, it differed considerably from that described for estuarine environments. Indeed, both prevalence and abundance of L. pectoralis and A. cornuta reached significant peaks in the summer, whereas the literature identifies the autumn as the season of maximum infection on estuarine flounder. Thus, the former period seems more favourable for the occurrence of epizooties of L. pectoralis and A. cornuta in flounder culturing systems running on seawater and operated in the studied or similar environments.

  2. Decline of flounder (Platichthys flesus (L.)) at the margin of the species' distribution range

    NASA Astrophysics Data System (ADS)

    Jokinen, Henri; Wennhage, Håkan; Lappalainen, Antti; Ådjers, Kaj; Rask, Martti; Norkko, Alf

    2015-11-01

    The Baltic Sea is undergoing large-scale environmental change due to eutrophication, climate change, over-exploitation and habitat destruction, with subsequent degradation of living conditions for many fish species. Signs of this unfavorable development are seen as population declines in species affected. We provide the first synthesis and characterization of the recent population decline in European flounder (Platichthys flesus (L.)) in the northern Baltic Sea, using available fishery-independent data from the Finnish coast, which is at the margin of the distribution range of this species. The objective was to document recent changes in the flounder population, identify the onset and quantify the magnitude of the change. The results showed substantial decreases in flounder numbers and biomass across the whole study area during recent decades. Based on the time series data available, flounder abundances declined by 46-97% from the 1990s to the 2000s, with top values in the mid-1990s and current low levels reached in the early 2000s. Additionally, signs of decreasing flounder size and condition were also observed. We discuss potential reasons for the development in terms of environmental change and fishing, and identify potential bottlenecks for population maintenance and mechanisms behind population change, thereby contributing to our general understanding of marginal flounder populations.

  3. Accumulation of organochlorines and mercury in flounder — an approach to pollution assessments

    NASA Astrophysics Data System (ADS)

    Köhler, A.; Harms, U.; Luckas, B.

    1986-12-01

    Levels of PCBs, HCB and Hg were determined in the muscle tissue of flounder ( Platichthys flesus L.), sampled at two sites of the highly industrialized Elbe estuary which is characterized by a decreasing gradient of contaminant levels in water and sediments towards the mouth of the river. The contaminant levels were compared to those found in muscle tissue of flounders caught in an unpolluted reference area, the Eider estuary. Juvenile flounders (1 2 cm total length) caught during their migration from the southern North Sea coast into the Elbe estuary in early summer showed a significantly higher level of contamination at both Elbe stations than those from the reference area. In the following spring, the flounders, having grown to a length of 12 14 cm, reflected the gradient of contaminants measured in water and sediment. However, during summer and late autumn a drastic increase in average contaminant concentration was observed in the muscle tissue of flounders taken from the less polluted estuarine site. It became evident that severe oxygen depletion in the heavily polluted area near Hamburg had provoked the migration of highly contaminated fish downstream to the less polluted sampling area; thus intermingling with the less contaminated flounder population of this region had occurred. The results obtained indicate that careful analysis of environmentally controlled behavioural patterns in the species used for monitoring purposes as well as an appropriate statistical treatment of the data gained from chemical analysis are essential for assessing the contaminant concentrations in organisms in relation to the pollution load of their habitats.

  4. The influence of environmental conditions on early life stages of flounder (Platichthys flesus) in the central Baltic Sea

    NASA Astrophysics Data System (ADS)

    Ustups, Didzis; Müller-Karulis, Bärbel; Bergstrom, Ulf; Makarchouk, Andrej; Sics, Ivo

    2013-01-01

    Flounder (Platichthys flesus) is a temperate marine fish that is well adapted to the brackish waters of the Baltic Sea. There are two sympatric flounder populations in the Baltic Sea, pelagic and demersal spawners, which differ in their spawning habitat and egg characteristics. In the present study, pelagic spawning flounder of the central Baltic Sea was studied. We examined whether variations in hydrological regime can explain fluctuations in flounder early life stages that have occurred over the past 30 years (1970-2005). Using generalized additive modeling to explain the abundance of flounder eggs and larvae in a Latvian ichthyoplankton dataset, we evaluate the hypothesis that the available reproductive volume, defined as the water column with dissolved oxygen larger than 1 ml/l and salinity between 10.6 and 12 PSU, affects the survival of flounder ichthyoplankton and determines recruitment success. Both reproductive volume and spawning stock biomass were significant factors determining flounder ichthyoplankton abundance. Different measures of water temperature did not contribute significantly to the variability of eggs or larvae. However, recruitment did not correlate to the supply of larvae. The findings presented in this study on the relationship between flounder reproduction, spawning stock biomass and reproductive volume, as well as the lack of correlation to recruitment, are valuable for the understanding of flounder ecology in the Baltic Sea, and for developing the management of the species.

  5. Trace metals in flounder, Platichthys flesus (Linnaeus, 1758), and sediments from the Baltic Sea and the Portuguese Atlantic coast.

    PubMed

    Polak-Juszczak, Lucyna

    2013-10-01

    Trace metals were examined in the muscle tissue of flatfish species of flounder, Platichthys flesus (Linnaeus, 1758), sediments from two southern Baltic Sea sites (Gdańsk Bay and Ustecko-Łebskie as a reference) and in two areas of the Portuguese Atlantic coast (Douro River estuary and Atlantic fishing ground as a reference) to evaluate spatial differences in trace metals. Additionally, the accumulation of trace metals in flounder of different length classes was assessed. Flounder from the Gdańsk Bay area contained twofold more cupper (Cu), lead (Pb) and mercury (Hg) than did flounder from the Douro River estuary, but zinc (Zn) and cadmium (Cd) were at similar concentrations. The sediments from Gdańsk Bay contained significantly more Zn and threefold more Cd, while concentrations of Cu and Pb were twofold lower. The concentrations of metals in the sediments did not correlate with those in the flounder. Spatial differences were noted in metal concentrations in flounder from the southern Baltic Sea and the Portuguese Atlantic coast as well as within these regions, with higher concentrations in the flounder from the Baltic Sea Gdańsk Bay. The flounder in length class 25-30 cm from Gdańsk Bay contained metal concentrations comparable to those of class 40-45 cm specimens from the Atlantic coast. The accumulation of metals in flounder length classes differed in the two regions.

  6. Fecundity of flounder, Pleuronectes flesus, in the Baltic Sea — Reproductive strategies in two sympatric populations

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Dahlman, Gry

    2010-10-01

    Two sympatric flounder populations with different reproductive strategies, offshore spawning at 10-20 psu producing pelagic eggs and coastal spawning at 5-7 psu with demersal eggs respectively, inhabit the brackish water Baltic Sea. Salinity governs the reproductive success by irregular saline water inflows and hence stock abundance and distribution. The potential fecundity (the standing stock of vitellogenic oocytes in the pre-spawning ovary) was assessed for fish sampled at five locations (two for offshore spawners and three for coastal spawners) along the salinity gradient (ICES SD 25, 27/28, 28 and 29). Multiple linear regression analysis resulted in r2-values of 0.698-0.894 for the respective sampling location with somatic weight or total fish length as the main predictor, and otolith weight (proxy for age) and oocyte density (by gravimetric counting) as additional predictors. Analysis by univariate regressions using GLM revealed significantly higher fecundity for coastal spawning- than offshore spawning flounder (˜ 69% more oocytes for an intermediate sized fish) but no intra-population differences. Similarly, gonad dry weight was significantly higher for coastal spawning flounder. Further, growth estimations indicated higher growth in offshore spawning- than in coastal spawning flounder suggesting that the coastal spawning population allocate relatively more resources into reproductive growth than somatic, potentially a result of strong selection for high fecundity of flounder producing demersal eggs due to poor egg survival for this spawning strategy. Earlier studies on fecundity of Baltic flounder are reviewed and discussed with consideration of inter-population differences questioning the idea of in general higher fecundity of flounder in the Baltic Sea.

  7. 77 FR 41332 - Fisheries of the Exclusive Economic Zone Off Alaska; Arrowtooth Flounder, Flathead Sole, Rex Sole...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... Economic Zone Off Alaska; Arrowtooth Flounder, Flathead Sole, Rex Sole, Deep-Water Flatfish, and Shallow- Water Flatfish in the Gulf of Alaska Management Area AGENCY: National Marine Fisheries Service (NMFS...: NMFS is prohibiting directed fishing for arrowtooth flounder, flathead sole, rex sole,...

  8. 77 FR 76950 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-31

    ... for each coastal state from North Carolina to Maine, and the summer flounder recreational harvest... recreational harvest limit. This rule corrects that error. DATES: Effective December 26, 2012, through December... an error in the commercial summer flounder quota and recreational harvest limit, which...

  9. N-Terminal region is responsible for chemotaxis-inducing activity of flounder IL-8.

    PubMed

    Kurata, Osamu; Wada, Shinpei; Matsuyama, Tomomasa; Sakai, Takamitsu; Takano, Tomokazu

    2014-06-01

    The objective of this study was to locate the functional region responsible for the chemotaxis-inducing activity of flounder interleukin 8 (IL-8), which lacks the glutamic acid-leucine-arginine (ELR) motif essential for the induction of neutrophil migration by mammalian IL-8. Using a human cell line, we produced a secretory recombinant protein of flounder IL-8, and analyzed its chemotaxis-inducing activity on leukocytes collected from the flounder kidney. The recombinant IL-8 induced significant migration in neutrophils, which were morphologically and functionally characterized. Using the Edman degradation method, the N-terminal amino acid sequence of rIL-8 was identified as VSLRSLGV. To examine the significance of the N-terminal region for the bioactivity of flounder IL-8, we prepared several recombinant proteins that containing mutations at the N-terminus. Modification of three residues (residues 9-11: serine-leucine-histidine) corresponding in position to the ELR motif in mammalian IL-8 did not reduce its chemotaxis-inducing activity. However, deletion of the first six or more residues significantly reduced its chemotaxis-inducing activity. We propose that residue 6 (leucine) at the N-terminus is important for the chemotaxis-inducing activity of flounder IL-8.

  10. Population structure of flounder (Platichthys flesus) in the Baltic Sea: differences among demersal and pelagic spawners.

    PubMed

    Florin, A-B; Höglund, J

    2008-07-01

    We found significant population structure and isolation by distance among samples of flounder (Platichthys flesus) in the Baltic, Kattegat and Skagerrak seas using microsatellite genetic markers. This pattern was almost entirely due to a difference between flounder that have demersal spawning in the northern Baltic, as compared to pelagic spawners in the southern Baltic and on the west coast of Sweden. Among demersal spawners we found neither genetic differentiation nor any isolation by distance among sampling sites. We speculate that demersal flounder are descendants of a population that colonized the Baltic previous to pelagic spawners. The demersal flounder may thus have had longer time to adapt to the low salinity in the Baltic, and accordingly display egg characteristics that make it possible to reproduce at the low salinity levels in the northern Baltic. Among pelagic spawners significant isolation by distance was detected. Pelagic spawners have previously been shown to display clinal variation in egg size, which allows them to float also at the moderate salinity levels up to the region north of the island Bornholm. Management units for harvesting should ideally be based on true biological populations, and for the commercially important flounder up to 15 different management stocks in the Baltic have been suggested. We could not find a population genetic foundation for such a high number of management units, and our data suggest three management units: the northern Baltic (demersal populations), southern Baltic with the Oresund straits and the most northwestern sampling sites (Skagerrak, Kattegat and North Sea).

  11. Diablo/SMAC: a novel biomarker of pollutant exposure in European flounder (Platichthys flesus).

    PubMed

    Zacchino, Valentina; Minghetti, Matteo; Centoducati, Gerardo; Leaver, Michael J

    2012-05-01

    Diablo (or SMAC) is a protein released from mitochondria following apoptotic stimuli and inhibits the actions of Inhibitors of Apoptosis (IAP) proteins. IAPs regulate the activity of caspases and NFkB, the primary executioners of apoptosis and of inflammation, respectively. Thus, Diablo is important for the regulation of cellular responses to damage. In Northern Europe, statutory governmental marine monitoring programs measure various biomarkers in flounder to indicate biological effects of pollutant exposure. More recently transcriptomic techniques have been applied in flounder to gain a more comprehensive understanding of pollutant effects, and to discover novel biomarkers. In most of these studies utilising flounder, Diablo was amongst the most highly increased transcripts identified. The aim of this study was to further examine piscine Diablo, at the gene level and mRNA level, after exposure to prototypical pollutants, and in flounder caught from polluted environments. The results show that two genes encoding Diablo exist in fish species, and in flounder one of these genes is increased in liver after exposure to polyaromatic hydrocarbons and polychlorinated biphenyls, and also in livers from fish living on contaminated estuarine sediments. Therefore, Diablo measurement has potential as a biomarker of pollutant exposure, and could indicate damaging effects of chemical contaminants.

  12. Food intake of young cod and flounder in a shallow bay on the Swedish west coast

    NASA Astrophysics Data System (ADS)

    Pihl, L.

    The importance of shallow soft bottom areas as nursery grounds for I-ground cod, Gadus morhua, and I- to IV-group flounder, Platichthys flesus, was investigated in a 20 000 m 2 bay, 0 to 1 m deep, on the Swedish west coast. To estimate the amount of visiting fish and their food intake the bay was enclosed with a net once a month from July to November 1979 and from April to November 1980. At each occasion about 60 cods and 8 to 50 flounders were caught. The total biomass of the cod and flounder was 1 to 14 kg and 2 to 13 kg wet weight, respectively. The cod preyed on mobile epifauna such as Carcinus maenas, Crangon crangon and Pomatoschistus spp., whereas the flounder was eating infauna mainly Mya arenaria, Cardium spp. and Nereis spp. The food intake within the area was calculated to approximate 35 and 10 kg wet weight from April to November for cod and flounder, respectively.

  13. Comparisons of liver proteomes in the European flounder Platichthys flesus from three contrasted estuaries

    NASA Astrophysics Data System (ADS)

    Galland, Claire; Dupuy, Célie; Capitaine, Carole; Auffret, Michel; Quiniou, Louis; Laroche, Jean; Pichereau, Vianney

    2013-01-01

    Estuaries are important areas highly susceptible to anthropogenic degradations like pollution. Estuarine species have thus to cope with many types of constraints depending on the estuaries' characteristics. The European flounder Platichthys flesus is considered as a sentinel species for the monitoring of estuarine water quality. In this study, juvenile flounders (0+ group) were sampled from three contrasted Channel estuaries, i.e. the Seine, the Canche and the Tamar, and we characterized their liver proteomes by using a two-dimensional electrophoresis based proteomic approach. We showed that 27 protein spots differentially accumulated between the 3 populations. Six of these proteins were identified by MALDI TOF-TOF mass spectrometry. Flounders from the Seine and from the Tamar, two highly polluted estuaries, displayed common differences, i.e. an increase of the energetic- and the glutathione-metabolism. The most accumulated protein in the Seine's samples (6.7-fold) was a Vitelline Membrane Outer layer protein 1 homolog, suggesting oogenesis deregulation in these juvenile (sexually immature) flounders. Future works applying this kind of proteomic approach on flounders experimentally exposed to conditions that mimic environmental constraints will help to better understand the significance of these environmental proteomic signatures.

  14. Stanniocalcin in the euryhaline flounder (Platichthys flesus): primary structure, tissue distribution, and response to altered salinity.

    PubMed

    Hang, Xiaoming; Balment, Richard John

    2005-11-01

    Stanniocalcin (STC) is a homodimeric glycoprotein hormone that was first discovered in fish, where it is largely produced by a unique endocrine gland, the corpuscles of Stannius (CS). In bony fish, it is thought to be an important regulator of calcium and phosphate uptake from the aquatic environment. This report describes the molecular cloning of STC from euryhaline flounder (Platichthys flesus) CS cDNA and genomic DNA. The flounder STC encodes a prehormone of 251 amino acids (aa) with a signal peptide of 17 aa, followed by another 15 aa sequence before the mature protein of 219 aa. The deduced aa sequence of flounder STC shows 62.9-89.0% similarity and 50.4-83.1% identity with other known fish STC sequences, but only 42.3% identity with mouse STC1, 24.4% identity with fugu and zebrafish STC2, and 22.3% identity with mouse STC2. Primary structural analysis demonstrated that flounder STC gene contains five exons in contrast to the four exons present in mammalian STC gene. RT-PCR revealed the expression of flounder STC mRNA to be widely spread in many tissues and organs, similar to the situation in mammals and other fish. Quantitative PCR (Q-PCR) was conducted to measure relative STC expression levels in the CS, which showed STC mRNA expression levels in seawater-adapted fish CS were about 3-fold higher than in freshwater-adapted fish CS.

  15. Investigation on health conditions of flounder and smelt in the Elbe estuary

    NASA Astrophysics Data System (ADS)

    Köhler, A.; Hölzel, F.

    1980-03-01

    Since 1958 the occurrence of flounder ( Platichthys flesus L.) and smelt ( Osmerus eperlanus L.) in the lower River Elbe has shifted gradually toward the mouth of the river into the North Sea; this may be due to periodical deprivation of oxygen and fluctuating peaks of toxic nitrite concentrations. The interior organs of both fish species caught in the Elbe estuary were examined. Macroscopic inspections revealed discolouring of the liver to be most pronounced in specimens 2 3 years of age. Cross-sections of the liver demonstrated histopathological symptoms of oedematous degeneration in smelt, and extreme lipoid vacuolation in flounder increasing with size and age of the fishes. The intestine of both species investigated showed massive desquamation defects of the mucosa, occurring in smelts shortly after hatching, and in flounders after immigration into the estuary. The observations made suggest the influence of toxic compounds distributed in the aquatic environment on the health of both species.

  16. A DNA expression array to detect toxic stress response in European flounder (Platichthys flesus).

    PubMed

    Williams, T D; Gensberg, K; Minchin, S D; Chipman, J K

    2003-10-29

    As a first stage in developing a DNA array-based approach to investigating the effects of pollutants on an environmentally relevant European fish species, we have constructed a 160-gene custom microarray for European flounder. Degenerate primers were used to amplify 110 different fragments of stress-related and other genes from European flounder cDNA and genomic DNA. Additionally, 22 fragments were obtained by suppressive subtractive hybridisation (SSH). These fragments were cloned and sequenced, then, with additional control genes, used to create a cDNA microarray for flounder. After optimisation of the arraying process, hepatic mRNA was isolated from flounder caught in the polluted Tyne and relatively unpolluted Alde estuaries. Fluorescent cDNA probes were synthesised from the mRNA and used in dual-colour hybridisations to the microarray. A number of transcripts were differentially expressed between Tyne and Alde female flounder but these changes were not significant, due to high inter-individual variation. However, in comparisons between Tyne and Alde male flounder, 11 transcripts were found to significantly differ in expression (P<0.05). Seven transcripts were more highly expressed in the Tyne male fish (CYP1A, UDPGT, alpha-2HS-glycoprotein, dihydropyrimidine dehydrogenase, Cu/Zn SOD, aldehyde dehydrogenase and paraoxonase). Four transcripts (Elongation factor 1 (EF1), EF2, Int-6 and complement component C3) were found to be significantly less abundant in the Tyne male fish. Selected genes were assayed by real-time PCR, then normalised to alpha-tubulin. These assays confirmed the significance of the array results for CYP1A, UDPGT and EF1, but not for Cu/Zn SOD. This study provides a link between traditional single-gene biomarker studies and the emerging field of eco-toxicogenomics, demonstrating the utility of microarray studies on environmentally sampled, non-model organisms.

  17. Tetroazolemycins A and B, two new oxazole-thiazole siderophores from deep-sea Streptomyces olivaceus FXJ8.012.

    PubMed

    Liu, Ning; Shang, Fei; Xi, Lijun; Huang, Ying

    2013-05-10

    Two new oxazole/thiazole derivatives, named tetroazolemycins A (1) and B (2), have been isolated from the acetone extract of the mycelium of Streptomyces olivaceus FXJ8.012 derived from deep-sea water, together with three known compounds, spoxazomicins A-C (3-5), isolated from the fermentation supernatant. The planar structure and relative configuration of tetroazolemycins were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR techniques, and showed to be new pyochelin-type antibiotics. Both compounds showed metal ion-binding activity and their Zn²⁺ complexes exhibited weak activity against pathogenic bacteria Klebsiella pneumoniae.

  18. High doses of corticosteroid suppress resistance to Ichthyophonus in starry flounder

    USGS Publications Warehouse

    Perry, J.A.; Kocan, R.M.; Winton, J.R.; Hershberger, P.K.

    2004-01-01

    Application of pharmacological doses of the corticosteroid dexamethasone phosphate to starry flounder Platichthys stellatus resulted in a predisposition to clinical ichthyophoniasis and a progression from latent Ichthyophonus infections to patent, histologically identifiable infections. Among Ichthyophonus-challenged starry flounder, the prevalences of clinical infections and histologically identifiable infections were significantly greater in two groups that received dexamethasone (100% and 31%, respectively) than in the respective control groups (8% and 0%). Proliferation of Ichthyophonus infections in corticosteroid-treated groups may have resulted from suppression of the cellular immune response that typically follows corticosteroid application; however, further studies are needed to determine whether these effects occur at lower, physiological concentrations of corticosteroids.

  19. Development and application of quantitative detection method for viral hemorrhagic septicemia virus (VHSV) genogroup IVa.

    PubMed

    Kim, Jong-Oh; Kim, Wi-Sik; Kim, Si-Woo; Han, Hyun-Ja; Kim, Jin Woo; Park, Myoung Ae; Oh, Myung-Joo

    2014-05-23

    Viral hemorrhagic septicemia virus (VHSV) is a problematic pathogen in olive flounder (Paralichthys olivaceus) aquaculture farms in Korea. Thus, it is necessary to develop a rapid and accurate diagnostic method to detect this virus. We developed a quantitative RT-PCR (qRT-PCR) method based on the nucleocapsid (N) gene sequence of Korean VHSV isolate (Genogroup IVa). The slope and R² values of the primer set developed in this study were -0.2928 (96% efficiency) and 0.9979, respectively. Its comparison with viral infectivity calculated by traditional quantifying method (TCID₅₀) showed a similar pattern of kinetic changes in vitro and in vivo. The qRT-PCR method reduced detection time compared to that of TCID₅₀, making it a very useful tool for VHSV diagnosis.

  20. In vitro effect of two commercial anti-coccidial drugs against myxospores of Kudoa septempunctata genotype ST3 (Myxozoa, Multivalvulida)

    PubMed Central

    Ahn, Meejung; Won, Seunghwan; Kang, Bongjo; Gong, Po; Yoo, Eunho; Dharaneedharan, Subramanian; Jang, Yeounghwan

    2017-01-01

    Kudoa septempunctata (Myxozoa: Multivalvulida) myxospores infect the trunk muscles of olive flounder (Paralichthys olivaceus). In this study, two popular commercially formulated anti-coccidial drugs (amprolium hydrochloride and toltrazuril) were serially diluted and incubated with purified mature Kudoa septempunctata myxospores. The viability of K. septempunctata spores was determined after a 2-day incubation followed by Hoechst 33342 and propidium iodide staining, and scanning electron microscopy. Amprolium hydrochloride significantly decreased spore viability (18% of control) at a concentration of 920 μg/mL, whereas toltrazuril showed almost no effect (83% of control). Viability of the control (untreated spores) was 90%. In vivo studies are required to confirm the efficacy of amprolium hydrochloride in fish infected with K. septempunctata myxospores on their growth and immune system performance. PMID:28322722

  1. Development and Application of Quantitative Detection Method for Viral Hemorrhagic Septicemia Virus (VHSV) Genogroup IVa

    PubMed Central

    Kim, Jong-Oh; Kim, Wi-Sik; Kim, Si-Woo; Han, Hyun-Ja; Kim, Jin Woo; Park, Myoung Ae; Oh, Myung-Joo

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a problematic pathogen in olive flounder (Paralichthys olivaceus) aquaculture farms in Korea. Thus, it is necessary to develop a rapid and accurate diagnostic method to detect this virus. We developed a quantitative RT-PCR (qRT-PCR) method based on the nucleocapsid (N) gene sequence of Korean VHSV isolate (Genogroup IVa). The slope and R2 values of the primer set developed in this study were −0.2928 (96% efficiency) and 0.9979, respectively. Its comparison with viral infectivity calculated by traditional quantifying method (TCID50) showed a similar pattern of kinetic changes in vitro and in vivo. The qRT-PCR method reduced detection time compared to that of TCID50, making it a very useful tool for VHSV diagnosis. PMID:24859343

  2. USE OF VIDEO TO ACCESS JUVENILE WINTER FLOUNDER DENSITIES AND HABITATS

    EPA Science Inventory

    We used a digital video camera mounted to a 1-m beam trawl together with an attached continuous recording YSI sonde and a GPS unit to quantify juvenile winter flounder (Pseudopleuronectes americanus) densities and fish habitat in Narragansett Bay, RI. The YSI sonde measured te...

  3. Philasterides dicentrarchi, a histophagous ciliate causing scuticociliatosis in olive flounder, Philasterides dicentrarchi--histopathology investigations.

    PubMed

    Harikrishnan, Ramasamy; Jin, Chang-Nam; Kim, Ju-Sang; Balasundaram, Chellam; Heo, Moon-Soo

    2012-03-01

    Philasterides dicentrarchi is a histophagous scuticociliate infecting Korean olive flounder farms in Jeju Island, South Korea, where it causes significant economic losses. However, the route of entry of these parasites in olive flounder is currently unknown. In the present study, we attempted experimental infection with different doses (concentrations) of P. dicentrarchi by intraperitoneal (IP) injection; maximum cumulative mortality of 95% was recorded on the administration of 2.1×10(8) ciliates/ml. In small size group (3 cm length, 24±2 gwt) the ciliates were found in connective tissues of muscle, fins, and nervous tissue while in large size group (5 cm length, 47±3 gwt), the ciliates were predominantly occurred with associated symptoms of liquefaction in the central nervous system. The major clinico-pathological manifestations were loss of scales, appearance of bleached spots that coalesced to form brownish patches, hemorrhagic, and severe dermal necrotic lesion. In addition there was degeneration of muscle fibers, necrosis of the hepatic parenchyma, and severe edema of the intestinal walls, extensive fouling, necrotic degeneration and hyperplasia in the gill bronchial epithelium. In this study, many ciliates were found in the blood vessel, brain, dorsal fins, muscle, kidney, and vertebra of infected flounder. The histopathological investigations are of significant importance in view of possible routes of entry into the host and doses of ciliates that trigger fast infection for potential utility of drugs as a strategy for the control of P. dicentrarchi in farmed olive flounder.

  4. RELATIONSHIPS BETWEEN JUVENILE WINTER FLOUNDER AND MULTIPLE-SCALE HABITAT VARIATION IN NARRAGANSETT BAY, RHODE ISLAND

    EPA Science Inventory

    A rapid random-sampling method was used to relate densities of juvenile winter flounder to multiple scales of habitat variation in Narragansett Bay and two nearby coastal lagoons in Rhode Island. We used a 1-m beam trawl with attached video camera, continuous GPS track overlay, ...

  5. Carbon and nitrogen isotope ratios of juvenile winter flounder as indicators of inputs to estuarine systems

    EPA Science Inventory

    Stable carbon and nitrogen isotope ratios were measured in the muscle tissues of young-of-the-year (YOY) winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems along the coast of Rhode Island, USA. These systems included three coastal lagoons (Ni...

  6. Intestinal helminth parasites in flounder Platichthys flesus from the River Thames: an infracommunity analysis.

    PubMed

    Guillen-Hernandez, S; Whitfield, P J

    2004-12-01

    An analysis was undertaken of intestinal helminth communities in flounder Platichthys flesus from two sites on the River Thames. A comparison was made between helminth community richness and diversity from these sites at the component and infracommunity levels. At the component community level, a richer and more diverse parasite community was found in flounder from the Tilbury location (marine influence) than that from the Lots Road location (freshwater influence). At the infracommunity level, more parasite species and parasite individuals per host were found at Lots Road and the percentage of similarity values were low at both locations. Helminth species with high prevalence values in the parasite communities of the flounder are the dominant species in any individual fish, harbouring multi-specific infections. The presence of more invertebrate species, which are intermediate hosts in the helminth life cycle in the Thames, fish vagility and the high prevalence and abundance values of Pomphorhynchus laevis in the flounder, may explain the differences between the two locations.

  7. Stabel Carbon and Oxygen Isotope Ratios of Otoliths from Juvenile and Adult Winter Flounder

    EPA Science Inventory

    This study was designed to determine if stable carbon (13C) and oxygen (18O) isotope ratios in otoliths could be used to differentiate the locations that serve as important nursery areas for winter flounder along the Rhode Island, USA coastline. In recent years the populations ...

  8. Stable Carbon and Oxygen Isotope Ratios of Otoliths Differentiate Winter Flounder (Pseudopleuonectes americanus) Habitats

    EPA Science Inventory

    Stable carbon (13C) and oxygen (18O) isotope ratios were measured in otoliths of juvenile winter flounder (Pseudopleuronectes americanus) collected from 18 nursery areas along the coast of Rhode Island, USA. Samples were obtained during June and July of 2002 from locations tha...

  9. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  10. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Yellowtail flounder sub-ACLs and AMs for the scallop fishery. 648.64 Section 648.64 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the...

  11. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  12. 50 CFR 648.100 - Summer flounder Annual Catch Limit (ACL).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The Summer Flounder Monitoring Committee shall recommend to the MAFMC separate ACLs for the commercial... recommended by the SSC. (1) Sector allocations. The commercial and recreational fishing sector ACLs will be... sector ACLs may be established on an annual basis for up to 3 years at a time, dependent on whether...

  13. WINTER FLOUNDER PSUEDOPLEURONECTES AMERICANUS HATCHING SUCCESS AS A FUNCTION OF BURIAL DEPTH IN THE LABORATORY

    EPA Science Inventory

    Previous experiments have shown that viable hatch of winter flounder eggs is reduced when the eggs are buried by as little as one half of one egg diameter (approximately 0.5 mm of sediment). This sensitivity to burial has resulted in seasonal banning of dredging in several north...

  14. 50 CFR Figure 6 to Part 223 - TED Extension in Summer Flounder Trawl

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false TED Extension in Summer Flounder Trawl 6 Figure 6 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES...

  15. 50 CFR Figure 6 to Part 223 - TED Extension in Summer Flounder Trawl

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false TED Extension in Summer Flounder Trawl 6 Figure 6 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED MARINE AND ANADROMOUS SPECIES...

  16. Accumulation of flounder larvae ( Platichthys flesus L.) in the Dollard (Ems estuary, Wadden Sea)

    NASA Astrophysics Data System (ADS)

    Jager, Zwanette

    1998-09-01

    In the context of an investigation of the importance of the Dollard as a nursery for flounder ( Platichthys flesus L.), the process of larval accumulation was studied. The hypothesis was addressed that freshwater discharge is a steering factor in larval transport caused by a larval preference for low-salinity water. Flounder larvae were simultaneously sampled at three locations during five tidal cycles in combination with measurements of physical variables. One location was in the main channel, the other two were in more peripheral channels of the Dollard. One of those is directly connected to a sluice by which freshwater is discharged into the Dollard. Concentrations of larvae varied during the tidal cycle at all locations: high initial values dropped after the middle of the flood to lower levels to increase again at the end of the ebb. In the channel connected to the sluice, significantly lower salinities were observed around low water than at the other locations, which coincided with significantly higher larval concentrations at the beginning of flood. Water transport as well as larval transport at this location showed a flood surplus on all sampling dates. Also, relatively more larvae were transported than expected according to the water transport compared to the other stations. Moreover, there was an ebb surplus in larval transport during some sampling dates at the other locations. The results indicated an accumulation of flounder larvae in the inner Dollard, and particularly in the area affected by the discharge of freshwater. Independent observations of settling flounder larvae in traps also indicated a concentration in the vicinity of the sluice. However, the sluice itself may form an effective barrier for flounder larvae that try to migrate to freshwater.

  17. Survey of the metazoan ectoparasites of the European flounder Platichthys flesus (Linnaeus, 1758) along the north-central Portuguese coast.

    PubMed

    Cavaleiro, Francisca I; Santos, Maria J

    2007-10-01

    A survey was undertaken to identify metazoan ectoparasite species on the European flounder, Platichthys flesus (Linnaeus, 1758), in 4 different locations off the north-central Portuguese coast. Parasites of 7 different taxa were found: Caligus diaphanus, Caligus sp., and Lepeophtheirus pectoralis (Copepoda: Caligidae); Acanthochondria cornuta (Copepoda: Chondracanthidae); Holobomolochus confusus (Copepoda: Bomolochidae); Nerocila orbignyi (Isopoda: Cymotholdae); and praniza larvae (Isopoda: Gnathiidae). Lernaeocera branchialis, a common European flounder parasite in the North and Baltic Seas, was not observed among the surveyed fish. Caligus diaphanus, Caligus sp., and Nerocila orbignyi are new host records. The high prevalence and intensity values recorded for L. pectoralis and A. cornuta suggest that both parasite species are common to the European flounder along the north-central Portuguese coast. In contrast, infection levels with respect to the other parasite taxa were, in most cases, comparatively lower, thereby indicating that they only occur occasionally among flounders in the surveyed area.

  18. Saptial and Temporal in Stable Carbon and Oxygen Isotope Ratios of Juvenile Winter Flounder Otoliths From Selected Nursery Areas

    EPA Science Inventory

    Winter flounder (Pseudopleuronectes americanus) populations have supported large commercial and recreational fisheries along the coast of New England. In recent years, however, the population of this important species has declined precipitously in some areas, especially Narragan...

  19. Assessment of Dredge-induced Sedimentation Effects on Winter Flounder (pseudopleuronectes americanus) Hatching Success: Results of Laboratory Investigations

    EPA Science Inventory

    Historically of significant commercial and recreational value, winter flounder (Pseudopleuronectes americanus) stocks have declined steadily over the last 20 years and are currently at an all-time low. Although overfishing and climate change have been implicated, habitat alterat...

  20. Assessment of Dredging-Induced Sedimentation Effects on Winter Flounder (Pseudopleuronectes americanus) Hatching Success: Results of Laboratory Investigations

    EPA Science Inventory

    Historically of significant commercial and recreational value, winter flounder (Pseudopleuronectes americanus) stocks have declined steadily over the last 20 years and are currently at an all-time low. Although overfishing and climate change have been implicated, habitat alterat...

  1. [Social behavior of the Wedge-capped Capuchin monkey Cebus olivaceus (Primates: Cebidae) in three zoological exhibits of Caracas, Venezuela].

    PubMed

    López, Marie Charlotte; Zaida, Tárano

    2008-09-01

    Captivity represents an extreme situation for primates, especially for those with large home ranges, and its effect on their behavior might be considerable. The Wedge-capped Capuchin Monkey Cebus olivaceus is the most common primate in Venezuelan zoos. To estimate the effect of confinement on C. olivaceus behavior, we analyzed the social behavior of three groups that differed in captivity conditions, in zoological exhibits in Caracas (Caricuao, Parque del Este, El Pinar). Caricuao's group moved freely over a non-fenced area of 15 ha, Parque del Este's and El Pinar's groups lived in relatively small outdoor enclosures. Social behaviors were described using focal-animal sampling, group scans and ad libitum sampling. The frequency, duration and time devoted to each behavior (per focal period per individual) were estimated. Relative dominance between pairs of individuals was established as well as affiliative associations. The repertory of social behaviors was similar between groups and to which has been observed in nature, but the duration and frequency of affiliative and agonistic interactions differed between groups. Affiliative behaviors were less frequent but longer in Caricuao than in the other two groups, while agonistic behaviors were more frequent in El Pinar and Parque del Este. Differences between groups are explained by variation in captivity conditions. We suggest that confinement generates social tension and favors agonism, while affiliative encounters help reduce this tension. On the other hand, differences in agonism between captive and natural groups may result form prolonged association, restrictions to keep optimal spacing or leave the group. All groups had some social structure (e.g., dominance ranks, association and repulsion between individuals) but the social dynamic was partly disrupted. Dominance ranks were not clear throughout the group, the top male was not dominant over the top female, dominant individuals did not interact affiliatively more

  2. Structure and absolute configuration of toxic polyketide pigments from the fruiting bodies of the fungus Cortinarius rufo-olivaceus.

    PubMed

    Gao, Jin-Ming; Qin, Jian-Chun; Pescitelli, Gennaro; Di Pietro, Sebastiano; Ma, Ya-Tuan; Zhang, An-Ling

    2010-08-07

    Two new polyketide-derived pigments, named rufoolivacins B (), and D (), with a 4',10-coupled aryl linkage between polysubstituted 1-naphthol and 1,4- or 1,2-anthraquinone, together with nine known metabolites including rufoolivacins A () and C (), have been isolated from the fruiting bodies of the Chinese toadstool Cortinarius rufo-olivaceus (basidiomycetes). Their structures were characterized on the basis of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HSQC, and HMBC). The axial chirality of and was assigned through analysis of their CD spectra and ZINDO and TDDFT calculations. Compounds and were found to be unusual natural products incorporating an ortho-anthraquinone chromophore. All the metabolites were shown to be toxic toward the brine shrimp.

  3. Gene expression responses of European flounder (Platichthys flesus) to 17-beta estradiol.

    PubMed

    Williams, Tim D; Diab, Amer M; George, Stephen G; Sabine, Victoria; Chipman, James K

    2007-02-05

    Male European flounder (Platichthys flesus) were intraperitoneally injected with 10mg/kg 17-beta estradiol and tissues taken from individuals over a timecourse of 16 days. The GENIPOL P. flesus cDNA microarray was employed to detect hepatic gene expression differences between fish treated with estradiol and saline controls. Known biomarkers of estrogen exposure, choriogenin L and vitellogenins, showed sustained induction over the time-course. Among 175 identified clones showing sustained statistically significant induction or repression, those associated with the Gene Ontology terms mitochondria, amino acid synthesis, ubiquitination and apoptosis were included amongst those induced while those associated with immune function, electron transport, cell signalling and protein phosphorylation were repressed. Thus, we show the gene expression response of an environmentally relevant fish species to a high dose of an estrogenic endocrine disruptor and also report the sequencing of a further 2121 flounder ESTs.

  4. Does the chronic chemical contamination of a European flounder population decrease its thermal tolerance?

    PubMed

    Lavergne, Edouard; Pedron, Nicolas; Calves, Isabelle; Claireaux, Guy; Mazurais, David; Zambonino-Infante, José; Le Bayon, Nicolas; Cahu, Chantal; Laroche, Jean

    2015-06-30

    Juvenile flounders (Platichthys flesus), collected in two estuaries with similar temperature regimes (the heavily polluted Seine and the moderately contaminated Vilaine), were submitted to a common garden experiment. After an acclimation period, both populations were challenged by a thermal stress (9-24°C for 15days, then maintenance at 24°C for 19days). The condition factor of the Vilaine fish increased in both conditions, while it decreased for the heated Seine flounders after 34days. The expression of genes related to the energetic metabolism was measured in the liver. The expression levels for ATP-F0 and COII were significantly reduced for heated vs. standard fish from both estuaries, while a decrease of the 12S expression was detected only in heated vs. standard fish from the Seine estuary. Thus, it is suggested that highly contaminated fish from Seine could display a lower tolerance to thermal stress, compared to moderately contaminated fish from Vilaine.

  5. DNA adduct analysis and histopathological biomarkers in European flounder (Platichthys flesus) sampled from UK estuaries.

    PubMed

    Lyons, B P; Stentiford, G D; Green, M; Bignell, J; Bateman, K; Feist, S W; Goodsir, F; Reynolds, W J; Thain, J E

    2004-08-18

    The presence of genotoxic and potentially carcinogenic chemical contaminants in the estuarine and coastal marine environment is well documented. In this study, European flounder (Platichthys flesus) sampled from eight UK estuaries were analysed for hepatic DNA adducts, using the 32P-postlabelling assay and liver histopathology as part of an on going survey to establish the health status of UK estuaries. Fish were collected from the estuaries Tyne, Mersey, Thames, Alde (reference site), Belfast, Forth, Clyde and Southampton. At the majority of contaminated sites (Southampton, Thames, Clyde, Tyne and Mersey) the predominant DNA adduct profile consisted of diagonal radioactive zones (DRZs). In contrast, flounder collected from the Forth, Alde and Belfast lacked DRZs with only background levels of DNA damage being observed. Statistically significant differences were observed between several of the sites sampled with the hepatic DNA adduct levels detected in flounder from Southampton, Thames and Clyde statistically elevated (P < 0.05) over those levels detected at the Tyne (Southampton and Thames only), Forth, Alde and Belfast. Histological analysis of these samples revealed a range of lesions including foci of cellular alteration, hepatocellular fibrillar inclusions, nuclear pleomorphisms along with non-toxicopathic changes/alterations, such as those associated with cell turnover (apoptosis, necrosis, regeneration) and immune-related functions (melanomacrophage aggregates, inflammation). Although it is difficult to associate higher prevalence of these lesion types with specific sites, generally, the lowest prevalence was seen in flounder captured from the Alde estuary, with higher prevalence (particularly of melanomacrophage aggregates, inflammation and necrotic foci) seen in fish from the contaminated sites.

  6. Genetic and physiological responses of flounder (Platichthys flesus) populations to chemical contamination in estuaries.

    PubMed

    Laroche, Jean; Quiniou, Louis; Juhel, Guillaume; Auffret, Michel; Moraga, Dario

    2002-12-01

    We sampled and analyzed European flounder (Platichthys flesus) from two highly contaminated estuaries (Seine and Loire, France) and one moderately contaminated estuary (reference site: Ster, France). Significant and convergent modifications of the allelic frequencies for the loci phosphoglucomutase (PGM), glucose phosphate isomerase 2 (GPI-2), mannose phosphate isomerase (MPI), and aspartate aminotransferase (AAT-2) were evident for fish in the contaminated sites versus fish from the reference site. Back-calculation from otoliths showed that the average growth rate of fish between the first and the second winter was greater at the reference site (approximately 150 mm/year) than at the contaminated sites (approximately 100 mm/year). Flounder from the reference site also had a higher condition factor (somatic wt/(fish length)3) compared to fish from the two contaminated sites. However, the observed pattern of growth rate and condition factor might be biased by particular environmental conditions other than contaminants and must be confirmed by more extensive study. Flow cytometry analysis of fish blood revealed a significant difference in the frequency of abnormal profiles for fish from the Seine (20%) versus from the Ster (3%). We interpret this result as a marked genotoxic effect of contaminants on fish in the Seine system. Some genotypes, such as PGM 85/85, appeared to be linked to the measured components of fitness, particularly to DNA integrity. Thus, these genotypes might be considered to be more tolerant to pollutants. The frequency of the PGM 85 allele was clearly elevated in flounder from the more contaminated sites, compared to flounder from the reference site.

  7. Evaluating the Hypoxia Response of Ruffe and Flounder Gills by a Combined Proteome and Transcriptome Approach

    PubMed Central

    Tiedke, Jessica; Borner, Janus; Beeck, Hendrik; Kwiatkowski, Marcel; Schmidt, Hanno; Thiel, Ralf; Fabrizius, Andrej; Burmester, Thorsten

    2015-01-01

    Hypoxia has gained ecological importance during the last decades, and it is the most dramatically increasing environmental factor in coastal areas and estuaries. The gills of fish are the prime target of hypoxia and other stresses. Here we have studied the impact of the exposure to hypoxia (1.5 mg O2/l for 48 h) on the protein expression of the gills of two estuarine fish species, the ruffe (Gymnocephalus cernua) and the European flounder (Platichthys flesus). First, we obtained the transcriptomes of mixed tissues (gills, heart and brain) from both species by Illumina next-generation sequencing. Then, the gill proteomes were investigated using two-dimensional gel electrophoresis and mass spectrometry. Quantification of the normalized proteome maps resulted in a total of 148 spots in the ruffe, of which 28 (18.8%) were significantly regulated (> 1.5-fold). In the flounder, 121 spots were found, of which 27 (22.3%) proteins were significantly regulated. The transcriptomes were used for the identification of these proteins, which was successful for 15 proteins of the ruffe and 14 of the flounder. The ruffe transcriptome dataset comprised 87,169,850 reads, resulting in an assembly of 72,108 contigs (N50 = 1,828 bp). 20,860 contigs (26.93%) had blastx hits with E < 1e-5 in the human sequences in the RefSeq database, representing 14,771 unique accession numbers. The flounder transcriptome with 78,943,030 reads assembled into 49,241 contigs (N50 = 2,106 bp). 20,127 contigs (40.87%) had a hit with human proteins, corresponding to 14,455 unique accession numbers. The regulation of selected genes was confirmed by quantitative real-time RT-PCR. Most of the regulated proteins that were identified by this approach function in the energy metabolism, while others are involved in the immune response, cell signalling and the cytoskeleton. PMID:26273839

  8. Isolation and characterization of 28 new microsatellite markers for European flounder (Platichthys flesus L.).

    PubMed

    Tysklind, Niklas; Neuparth, Teresa; Ashcroft, Gregg R; Taylor, Martin I; Lyons, Brett P; McCarthy, Ian D; Carvalho, Gary R

    2009-05-01

    The European flounder (Platichthys flesus L.) is used in ecotoxicological studies to provide detailed information on the effects of pollution on individual fish. Data on population and evolutionary level effects are, however, limited. Here, the isolation and characterization of 28 novel species specific microsatellite loci are presented. The number of alleles ranged from 8 to 38, and observed heterozygosity from 0.542 to 1.

  9. Influence of sediment contaminated with untreated pulp and paper mill effluent on winter flounder, Pleuronectes americanus.

    PubMed

    Khan, R A

    2010-01-01

    This study was conducted to ascertain the influence of sediment contaminated with pulp and paper mill effluent in a fjord on winter flounder, Pleuronectes americanus, based on a laboratory study. Flounder, captured from a pristine site, were exposed in a flow-through system for 16 weeks to sediment collected at 2, 5, 7, and 10 km from the outfall. A group of controls was placed in uncontaminated sediment. Mortality occurred almost exclusively in fish exposed to sediment taken from 2 km than from more distant sites. Additionally, the condition factor was lower, the liver was enlarged, and toxicopathic lesions in the liver and spleen were significantly greater in fish submerged in the sediment than in fish from the more distant locations or the controls. Two ectoparasites including a ciliate, Trichodina jadranica, and a monogenean, Gyrodactylus pleuronecti, were observed only in the control group, while a digenean in the digestive tract, Steringophorus furciger, was more abundant in fish exposed to sediment from sites more distant from the outfall and the controls than at 2 km. Comparison of these results with data from a previous gradient field study on biological variables in winter flounder, captured at 2, 5, 7, and 10 km down-current from the outfall, revealed an enlarged liver that was associated with elevated levels of detoxification of hepatic enzymes and prevalence of toxicopathic lesions in both the liver and the spleen; these were significantly greater in samples taken nearest to the outfall from the mill than at more distant sites. Moreover, two metazoan parasites, S. furciger (Digenea) and Echinorhynchus gadi (Acanthocephala), in the digestive were more abundant in samples taken at farther locations and also from the reference sites. These results, based on a laboratory study, are in agreement with previous observations that winter flounder exposed to sediment at the site nearest to the outfall, where high concentrations of toxic contaminants persisted

  10. 50 CFR 648.64 - Yellowtail flounder sub-ACLs and AMs for the scallop fishery.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 12 2012-10-01 2012-10-01 false Yellowtail flounder sub-ACLs and AMs for...-ACLs and AMs for the scallop fishery. (a) As specified in § 648.55(d), and pursuant to the biennial... specified in § 648.90(a)(4)(iii)(C) of the NE multispecies regulations, the sub-ACLs for the 2011...

  11. Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

    NASA Astrophysics Data System (ADS)

    Song, Zhidong; Wang, Jiying; Qiao, Hongjin; Li, Peiyu; Zhang, Limin; Xia, Bin

    2016-09-01

    Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.

  12. Screening of hydrophobic DNA adducts in flounder (Platichthys flesus) from the Baltic Sea.

    PubMed

    Malmström, C; Konn, M; Bogovski, S; Lang, T; Lönnström, L-G; Bylund, G

    2009-12-01

    Neoplasia and other histopathological lesions in flounder (Platichthys flesus) liver have been investigated in several European sea areas, including the Baltic Sea. Several studies have been able to link neoplasm epizootics in fish with the exposure to genotoxins such as polycyclic aromatic hydrocarbons (PAHs). The level of hydrophobic DNA adducts in tissue DNA reflects the exposure of the organism to PAHs. Using hydrophobic DNA adduct levels as biomarkers, possible PAH exposure was assessed in flounder from 10 different sites in the Baltic Sea, collected during the years 1995-1997. The results show that the overall levels of hepatic DNA adducts were low and, in general, the chromatograms appeared clean. The highest levels of DNA adducts were found at two sites in the southern Baltic Sea. There were no statistically significant differences in adduct levels between the sites. Our results indicate that flounder from studied off shore sites of the Baltic Sea had not been exposed to a greater extent to large polycyclic hydrophobic hydrocarbons in their environment.

  13. Habitat distribution model for European flounder juveniles in the Venice lagoon

    NASA Astrophysics Data System (ADS)

    Zucchetta, Matteo; Franco, Anita; Torricelli, Patrizia; Franzoi, Piero

    2010-07-01

    In order to identify nursery habitats for Platichthys flesus in the Venice lagoon we developed a generalized additive model relating juvenile flounder's distribution to environmental variables. A field survey was conducted between March 2004 and June 2005 and between February and October 2008 in the central and Northern sub-basins of the lagoon. Each station was sampled by means of a beach seine net and characterized collecting the main chemico-physical variables, such as water temperature, salinity, turbidity, dissolved oxygen content and bottom grain size. Main winds fetches were also considered, and estimated in a GIS environment. A logistic model was fitted, and evaluated on an independent dataset. The response curves allowed to identify the role of the environmental parameters in explaining the distribution of the juvenile flounder: turbidity, salinity and sand content revealed to be the most important factors, showing the preference for mesohaline turbid waters together with a low sand content of the sediment. The application of this model to continuous surfaces of the environmental variables allowed the creation of potential habitat distribution maps. In this way it has been possible to recognize several areas covering a key role for the juveniles of flounder, located mainly in the inner part of the lagoon.

  14. Measuring some flounder (Platichthys flesus L.) innate immune responses to be incorporated in effect biomonitoring concepts

    NASA Astrophysics Data System (ADS)

    Skouras, Andreas; Steinhagen, Dieter

    2003-10-01

    For an implementation of innate immune responses of flounder (Platichthys flesus) in an integrated biological effect monitoring concept, leucocytes were isolated from peripheral blood, head kidney and spleen, and analysed for their capacity to mount a respiratory burst response upon phorbol ester stimulation. Responding cells were identified by reduced nitro-blue-tetrazolium salt deposits and by dihydro-rhodamine fluorescence in light microscope and flow cytometric analysis. Responding cells were found in head kidney derived cell suspensions rather than in peripheral blood or spleen. Parallel cytometric and microscopic analysis indicated that responding cells had a granulocyte or monocyte morphology, were alpha-naphtyl-esterase or myeloperoxidase positive and in flow cytometry exhibited a characteristic forward and side scatter (FSC/SSC) pattern. These cells represented 30-40% of head kidney derived cell suspensions and only 4-5 % of peripheral blood and spleen. In order to reduce sampling effort in field studies, leucocyte cell suspensions derived from flounder head kidney could be used in respiratory burst assays without further enrichment protocols. This paper combines, for the first time, conventional and cytometric analysis of phagocytes derived from flounder peripheral blood and head kidney.

  15. Liver histopathology in Baltic flounder (Platichthys flesus) as indicator of biological effects of contaminants.

    PubMed

    Lang, Thomas; Wosniok, Werner; Barsiene, Janina; Broeg, Katja; Kopecka, Justyna; Parkkonen, Jari

    2006-01-01

    Results are presented of a study on liver histopathology in Baltic flounder (Platichthys flesus) carried out in 2001 and 2002 in four coastal sampling areas of the Baltic Sea: Kvädöfjärden (Swedish east coast, reference area), Klaipeda-Butinge (Lithuanian coast), Gulf of Gdansk (Polish coast), and Wismar Bay (German coast) within the framework of the EU-funded BEEP project. Liver lesions were diagnosed and categorised using standardised methodologies and, for a spatial and temporal assessment of the prevalence and types of lesions detected, a scoring system was applied, involving the calculation of mean histopathology lesion scores. 83.0% of the 436 female flounder examined (size range: 20-43 cm total length, age range: 2-8 years) were affected by liver lesions, out of which 74.3% were assigned to the category of non-specific, 3.4% to the category of early toxicopathic non-neoplastic, 4.6% to the category of pre-neoplastic and 0.7% to the category of neoplastic lesions. Mean lesions scores were highest in the areas at the Lithuanian and Swedish coast and there is indication of an impact of the age structure of the flounder populations studied, the sampling season as well as of contaminant effects.

  16. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (North Atlantic): Winter flounder

    SciTech Connect

    Buckley, J.

    1989-01-01

    Species profiles are literature summaries of the taxonomy, life history, and environmental requirements of coastal fishes and aquatic invertebrates. They are designed to assist with environmental impact assessments. From 1935 to 1980, the annual commercial landings of winter flounder in New England ranged from 6000 to 15000 t; the sport catch exceeded the commercial catch in some years. Winter flounder are found in waters with temperatures of 0 to 25 /degree/C and they usually spawn at 0 to 3 /degree/C. Reported fecundities are 0.5 to 1.5 million eggs per female. Metamorphosis from larva to juvenile is complete in 49-80 days, depending on temperature. Juveniles remain in or near shallow natal waters for much of their first 2 years. Adults of some populations move more than 3 miles offshore to cooler waters in summer. These adults live in shallow inshore waters in winter and early spring. Adult winter flounder feed largely on annelids, cnidariids, and mollusks. 58 refs., 2 figs., 1 tab.

  17. Integrative taxonomy of Anisakidae and Raphidascarididae (Nematoda) in Paralichthys patagonicus and Xystreurys rasile (Pisces: Teleostei) from Brazil.

    PubMed

    Fonseca, Michelle Cristie Gonçalves da; Knoff, Marcelo; Felizardo, Nilza Nunes; Di Azevedo, Maria Isabel N; Torres, Eduardo José Lopes; Gomes, Delir Corrêa; Iñiguez, Alena Mayo; São Clemente, Sérgio Carmona de

    2016-10-17

    Thirty-six Paralichthys patagonicus and 30 Xystreurys rasile were collected in the state of Rio de Janeiro, Brazil to investigate the presence of anisakid and raphidascaridid nematodes. Anisakis typica, Terranova sp., Contracaecum sp., Hysterothylacium deardorffoverstreetorum, and Raphidascaris sp. were identified using integrative taxonomy of morphological and genetic data. Morphological and morphometric analysis was conducted using bright field microscopy with scanning electron microscopy for topographic characterization of the cuticular surface. Phylogenetic analysis, using ITS and cox2 molecular targets, clearly demonstrated the species identification of A. typica and H. deardorffoverstreetorum and the high diversity of H. deardorffoverstreetorum. This is the first report of A. typica, H. deardorffoverstreetorum, and Raphidascaris sp. parasitizing P. patagonicus and X. rasile.

  18. A New PCR-Based Method Shows That Blue Crabs (Callinectes sapidus (Rathbun)) Consume Winter Flounder (Pseudopleuronectes americanus (Walbaum))

    PubMed Central

    Collier, Jackie L.; Fitzgerald, Sean P.; Hice, Lyndie A.; Frisk, Michael G.; McElroy, Anne E.

    2014-01-01

    Winter flounder (Pseudopleuronectes americanus) once supported robust commercial and recreational fisheries in the New York (USA) region, but since the 1990s populations have been in decline. Available data show that settlement of young-of-the-year winter flounder has not declined as sharply as adult abundance, suggesting that juveniles are experiencing higher mortality following settlement. The recent increase of blue crab (Callinectes sapidus) abundance in the New York region raises the possibility that new sources of predation may be contributing to juvenile winter flounder mortality. To investigate this possibility we developed and validated a method to specifically detect winter flounder mitochondrial control region DNA sequences in the gut contents of blue crabs. A survey of 55 crabs collected from Shinnecock Bay (along the south shore of Long Island, New York) in July, August, and September of 2011 showed that 12 of 42 blue crabs (28.6%) from which PCR-amplifiable DNA was recovered had consumed winter flounder in the wild, empirically supporting the trophic link between these species that has been widely speculated to exist. This technique overcomes difficulties with visual identification of the often unrecognizable gut contents of decapod crustaceans, and modifications of this approach offer valuable tools to more broadly address their feeding habits on a wide variety of species. PMID:24454797

  19. Comparison of common persistent organic pollutants (POPs) in flounder (Platichthys flesus) from the Vistula (Poland) and Douro (Portugal) River estuaries.

    PubMed

    Waszak, Ilona; Dabrowska, Henryka; Komar-Szymczak, Katarzyna

    2014-04-15

    Groups of flounder (Platichthys flesus) females were collected in 2011 from the Vistula River and the Duoro River estuaries and corresponding reference sites in the southern Baltic Sea and Portuguese coast of the Atlantic Ocean to measure and compare the levels and profiles of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). The estuaries' sediments were also investigated. Several differences were found in the POPs between the estuaries and between the two marine regions, which were highlighted by PCA. The Vistula River estuary POPs, significantly higher than in the Douro River estuary, were dominated by DDTs followed by PCBs. PBDEs levels, indifferent between the estuaries, were relatively low. The POP levels in flounder and sediment evaluated against environmental assessment criteria (EACs) indicated that none of the measured contaminants for which EAC had been established exceeded the criterion, except for CB-118 in flounder from the Vistula River estuary.

  20. Assessment of the European flounder responses to chemical stress in the English Channel, considering biomarkers and life history traits.

    PubMed

    Dupuy, Célie; Galland, Claire; Pichereau, Vianney; Sanchez, Wilfried; Riso, Ricardo; Labonne, Maylis; Amara, Rachid; Charrier, Grégory; Fournier, Michel; Laroche, Jean

    2015-06-30

    A multi-biomarker approach was developed to evaluate responses of European flounder (Platichthys flesus) in three contrasted estuaries over the English Channel: the Canche (pristine site), Tamar (heavy metals and PAHs contamination) and Seine (heavily pollution with a complex cocktail of contaminants). The condition factor and several biomarkers of the immune system, antioxidant enzymes, energetic metabolism and detoxification processes were investigated in young-of-the-year (0+) and one-year-old (1+) flounder. Results underlined the difference between the pristine site and the Seine estuary which showed a lower condition factor, a modulation of the immune system, a higher Cytochrome C oxidase activity, and an up-regulation of BHMT expression. The moderate biomarker responses in the Tamar fish could be linked to the specific contamination context of this estuary. Flounder life history traits were analyzed by otolith microchemistry, in order to depict how the fish use their habitat and thus respond to chemical stress in estuaries.

  1. Two species of commercial flatfish, winter flounder, Pleuronectes americanus, and American plaice, Hippoglossoides platessoides, as sentinels of environmental pollution.

    PubMed

    Khan, R A

    2010-08-01

    Two species of marketable-size flatfish, winter flounder (Pleuronectes americanus) and American plaice (Hippoglossoides platessoides) from a fjord, were examined as sentinels for the effects of effluent discharged by a pulp and paper mill in Newfoundland, Canada. Reference samples for comparison were obtained from a pristine fjord. Condition factor, lymphocyte levels and the abundance of two intestinal parasites were significantly greater in flounder and plaice sampled at the reference site while macroscopic and microscopic lesions, and hepatic somatic indices were greater in flatfish taken from the contaminated site. These results suggest that both species of commercial flatfish are useful as sentinels for studying environmental pollution.

  2. Evaluation of protein extraction protocols for 2DE in marine ecotoxicoproteomics.

    PubMed

    Wu, Huifeng; Ji, Chenglong; Wei, Lei; Zhao, Jianmin

    2013-11-01

    In ecotoxicoproteomics, an accurate and reproducible extraction of proteins is a critical step for 2DE analysis and further protein identification using MS. The criteria for the assessment of protein extraction quality include protein yield, protein spots resolved in a 2DE gel, matched protein spots in replicate gels, reproducibility, and compatibility with MS. In this work, we evaluated three protein extraction systems, straightforward lysis buffer, trichloroacetic acid-acetone, and TRIzol reagent with some modifications, for the protein extraction from three animal species including mussel Mytilus galloprovincialis, flounder Paralichthys olivaceus, and polychaete Nereis diversicolor used in marine ecotoxicology. Our results indicated that these methods could extract significantly different protein profiles. The method using TRIzol reagent resulted in the most matched protein spots resolved in four replicate 2DE gels and highest reproducibilities for the gill of M. galloprovincialis and liver of P. olivaceus. However, a modified trichloroacetic acid-acetone solvent system was best for the whole soft tissue of N. diversicolor. This work provides the fundamental information of the extraction quality of protein extraction protocols from different marine animals, which may facilitate the selection of a suitable protein extraction protocol for ecotoxicoproteomics.

  3. The migration patterns of the European flounder Platichthys flesus (Linnaeus, 1758) (Pleuronectidae, Pisces) at the southern limit of its distribution range: Ecological implications and fishery management

    NASA Astrophysics Data System (ADS)

    Morais, Pedro; Dias, Ester; Babaluk, John; Antunes, Carlos

    2011-02-01

    This study aims to determine the diversity of migration patterns of the European flounder ( Platichthys flesus (Linnaeus, 1758)) present in the Minho estuary and in the adjacent coastal area (NW-Iberian Peninsula). Assessing the diversity of flounder migration patterns at the southern limit of its distribution allows the determination of characteristics of the species' ecology and provides useful information for fishery managers, since it is a regionally important estuarine fishery. An unexpected result of our study was that flounder appears to spawn in both estuarine and coastal areas and not just in coastal areas as was previously widely accepted. Our interpretation of otolith strontium distribution patterns from flounder specimens collected in the freshwater tidal area of the Minho estuary and in the lower estuary suggested that the flounders hatched in the estuary, while only 6.7% of those captured in the coastal area hatched in the coastal area. Ultimately, studies aimed at collecting larval stages and adult flounders must be made to confirm that flounders spawn in the estuary and to define new and better scientifically supported fishing policies, or simply to confirm the existing ones regarding temporal and spatial closures for each gear used in the Minho estuary.

  4. Selective Tidal Stream Transport of Flounder Larvae ( Platichthys flesusL.) in the Dollard (Ems Estuary)

    NASA Astrophysics Data System (ADS)

    Jager, Z.

    1999-09-01

    The vertical distribution of flounder larvae (Platichthys flesus L.) was investigated in the Dollard (Ems estuary, Wadden Sea) in relation to tidal phase and physical variables in order to address the question whether larval migration into the nursery is accomplished by passive transport, or is influenced by active (swimming) behaviour. Larval concentrations were measured twice per hour simultaneously at three water depths from low water (LW), through high water (HW), to the next LW slack. Physical variables were measured at the same time. Maximum concentrations of flounder larvae were 433 m-3in 1994 and 40 m-3in 1995. There were tidal variations in larval concentrations in all three water layers and the vertical distribution varied as well. The highest larval concentrations were usually found near the surface during flood and the lowest in the midwater layer during the ebb. In contrast to larval concentrations, turbidity was always highest near the bottom. The observation that larval vertical distributions deviate from those of suspended matter and vary in a different way led to the rejection of an entirely passive transport mechanism. The vertical distribution of larvae during flood supported the selective tidal stream transport hypothesis, but the relatively high number of flounder larvae in the surface layer during ebb was in contradiction with it. The high surface concentrations during ebb may have been caused by different origins of the water layers and thus larvae, or by an inability of the metamorphosing larvae to resist the strong ebb currents. The data suggest that the transport process inside the nursery may favour retention.

  5. Transport and retention of flounder larvae ( Platichthys flesus L.) in the Dollard nursery (Ems estuary)

    NASA Astrophysics Data System (ADS)

    Jager, Zwanette

    2001-05-01

    Variability in tidal transport of larval flounder ( Platichthys flesus L.) in the Dollard was investigated to estimate the quantity of larvae that are annually retained in the nursery based on simultaneous measurements of water transport and larval concentrations. Sampling was done three times per hour in the main channel in the Dollard, during 35 tidal cycles divided over 1993, 1994 and 1995. In 1993, additional sampling was carried out simultaneously during eight tidal cycles in a subsidiary channel. Larval concentrations showed marked tidal variations at all time scales and indicated a patchy spatial distribution. The estimated net tidal transport of larvae was not correlated to the net tidal transport of water. However, a higher net water transport coincided with higher retention, defined as the percentage of net larval transport divided by the flood larval transport. Also, relatively longer duration of the flood than the ebb period (tidal asymmetry) was positively correlated with both net tidal water transport and larval retention. The wind direction significantly affected the net water transport at the cross-section in the main channel, whereas wind speed was not significant. The flood transport, but not the ebb or net transport, was significantly higher during spring tide following full moon than during the other lunar phases. The net tidal transport of larvae was much more variable in 1994 than in 1993 and 1995, frequently resulting in ebb surpluses in larval transport. Despite higher mean concentrations, the estimated net larval input was lower in 1994 than in 1993. This corresponded neither with the observed abundance estimates of juvenile flounder in the Dollard in these two years, nor with the abundance index obtained from routine surveys. The total larval input better reflects the juvenile flounder abundance. Variability in water circulation, influenced by varying wind conditions, and its effect on larval transport and retention is an important source

  6. Visualization of primordial germ cells in the fertilized pelagic eggs of the barfin flounder Verasper moseri.

    PubMed

    Goto, Rie; Saito, Taiju; Kawakami, Yutaka; Kitauchi, Tomoe; Takagi, Misae; Todo, Takashi; Arai, Katsutoshi; Yamaha, Etsuro

    2015-01-01

    Primordial germ cells (PGCs) appear during early embryogenesis and differentiate into gametes through oogenesis or spermatogenesis. Teleost PGCs can be visualized by injecting RNA transcribed from the fusion product of a fluorescent protein gene attached to the 3' untranslated region (3'UTR) of zebrafish nanos3 (zf-nos3). Although this method has been widely applied to teleost PGCs, the visualization of PGCs in pelagic species that have eggs with a hard chorion is more problematic due to the technical difficulty of microinjection into their eggs. In this study, we developed a reliable method for microinjection of fertilized eggs in a pelagic species, the barfin flounder. Using a microneedle with a constriction "brake", we were able to introduce gfp-nos3 3'UTR mRNA into embryos and to determine the origin and migration route of PGCs. We also isolated the barfin flounder nos3 (bf-nos3) gene to compare its 3'UTR sequence with that of zebrafish. The 3'UTR of the bf-nos3 sequence was longer than that of zf-nos3. However, PGCs were also visualized after injection of gfp-bf-nos3 3'UTR mRNA both in zebrafish and barfin flounder. These results suggest that the function of nos3 is conserved between these species regardless of the sequence differences. The method developed here for labeling PGCs with gfp-nos3 mRNA will provide a means to study PGC development in the embryos of a wide range of marine fish species.

  7. The metabolism of polycyclic aromatic hydrocarbons by two marine fishes: the little skate, Raja erinacea and the winter flounder, Pseudopleuronectes americanus

    SciTech Connect

    Foureman, G.L.

    1982-01-01

    Hepatic cytosolic fractions from male little skates exhibited high specific rates of enzymatic conjugation of glutathione with the polycyclic aromatic hydrocarbon (PAH) oxide, benzo(a)pyrene 4,5-oxide (4,5-BPO). High performance liquid chromatography analysis demonstrated that all hepatic skate tranferases showed strict configurational stereoselectivity for the R carbons in enantiomeric 4,5-BPO, only the S products were observed in enzymic reaction mixtures. Rates of metabolism of the PAH benzo(a)pyrene (i.e., AHH activity) varied markedly in hepatic homogenates prepared from feral winter flounder caught in the Gulf of Maine. Treatment of feral flounder with either a PAH or a PAH-type compound resulted in induced AHH activities in the liver of all flounder so treated. ANF (7,8-benzoflavone) acted to inhibit the hepatic AHH activity in all treated fish as it did in 64% of the feral flounder examined. Electrophoretic analysis of hepatic microsomes from flounder treated with either a PAH or a PAH-type compound showed a novel or enriched polypeptide species at approximately 57,000 MW. A polypeptide species of similar MW was only faintly discernable in hepatic microsomes from feral flounder whose hepatic AHH activities were much lower than that of the treated flounder whereas a band of similar molecular weight was prominent in hepatic microsomes from feral flounder with high hepatic AHH activities. These results suggest that many of the flounder in this area of Maine have induction of their hepatic monooxygenase systems similar to that caused by PAH or PAH-type compounds.

  8. A Case Study of the Effects of Dredging in Narrgansett Bay (RI, USA) on Winter Flounder Eggs

    EPA Science Inventory

    Seasonal dredging constraints have been established in several northeastern U.S. estuaries with the intent to protect winter flounder (Pseudopleuronectes americanus). A major source of concern is impacts on demersal eggs due to elevated sedimentation rates during the winter-earl...

  9. Availability of cadmium and zinc from sewage sludge to the flounder, Platichthys flesus, via a marine food chain.

    PubMed

    Burgos, M G; Rainbow, P S

    2001-06-01

    This paper examines the potential availability to a demersal fish of cadmium and zinc associated with digested sewage sludge, via a food chain as well as directly from the sludge, and the tissue distribution and possible excretion of any accumulated cadmium and zinc. Radioactive tracer techniques were used in order to follow the food chain transfer of the metals. Flounder (Platichthys flesus) accumulated cadmium both directly from sludge (delivered in newly ingested unassimilated gutfuls in the amphipods) and in assimilated form from the tissues of the amphipod crustacean Corophium volutator that had been feeding on a sludge-sediment mixture. Cadmium from both sources could be excreted by the fish. The concentration of cadmium within the whole fish increased as the input of cadmium in the diet increased. Zinc, similarly, is available to the flounder both directly from sludge and from zinc accumulated in C. volutator. Only a limited increase in net accumulation of zinc by the flounder was observed upon increased inputs of zinc through the diet, perhaps indicating some regulation of body zinc concentration by the flounder.

  10. 77 FR 24151 - Fisheries of the Northeastern United States; Summer Flounder, Scup, and Black Sea Bass Fisheries...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-23

    ... are not overfished or subject to overfishing in 2012. This final rule makes no changes to the interim... Flounder The updated stock assessment overfishing limit (OFL) is 31,588,000 lb (14,328 mt). The projected... the Council's risk policy results in an overfishing risk tolerance (P*) of 0.40, or a 40- percent...

  11. 77 FR 48916 - Fisheries of the Exclusive Economic Zone Off Alaska; Arrowtooth Flounder in the Bering Sea and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ... available data and finds that the ITAC for arrowtooth flounder in the BSAI needs to be supplemented from the... responding to the most recent fisheries data in a timely fashion and would delay the apportionment of the non... plan for the fishing season, and to avoid potential disruption to the fishing fleet and...

  12. IMPACT OF ELEVATED TEMPERATURE ON THE GROWTH, SURVIVAL, AND TROPHIC DYNAMICS OF WINTER FLOUNDER LARVAE: A MESOCOSM STUDY

    EPA Science Inventory

    Winter flounder (Pseudopleuronectes americanus) is a dominant commercial fish in Narragansett Bay, Rhode Island, and yet factors controlling its recruitment remain unclear. An experiment was conducted with six 13-m3 land-based mesocosms (5 m deep) from February to April 1997 to a...

  13. Nitrogen Isotope Ratios of Juvenile Winter Flounder as an Indicator of Anthropogenic Nitrogen Inputs to Estuarine Systems

    EPA Science Inventory

    Nitrogen isotope ratios (15N) were measured in muscle tissue of juvenile winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems (lagoons, river, bay) along the coast of Rhode Island, USA over a three-year period. Significant differences i...

  14. Flounder growth and production as indicators of the nursery value of marsh habitats in a Mediterranean lagoon

    NASA Astrophysics Data System (ADS)

    Franco, Anita; Fiorin, Riccardo; Zucchetta, Matteo; Torricelli, Patrizia; Franzoi, Piero

    2010-11-01

    Estuarine marshes are known as suitable nursery areas for many marine migrant fishes, such as flounder. The potential nursery value of such habitats was investigated in the Venice lagoon, by using growth and production of 0-group flounder as indicators. Size-frequency distribution analysis was performed on fish samples collected fortnightly, from March 2004 to June 2005, in two marsh sites, Dese and Tessera, differing in their origin and environmental conditions. Samples were mostly composed of juvenile individuals, belonging to 0- and 1-group cohorts (the latter being present in Tessera only). A higher total production, either annual or monthly, and faster growth of 0-group flounder was observed in Dese, associated to a higher ecological performance of 0-group individuals in this site, as indicated by the higher P:B ratio values. Dese is a site located in a marsh complex characterized by the relevant influence of a nearby river, and the observed higher potential nursery value of this marsh area with respect to the other is discussed in the light of the higher trophic status and other environmental conditions in this site. The production results were also compared to those from other estuarine environments commonly acknowledged as important nurseries for European flounder.

  15. Sex differences in hepatic lipids of Toxaphene-exposed juvenile yellowtail flounder (Pleuronectes ferrugineus Storer).

    PubMed

    Scott, K D; Fåhraeus-Van Ree, G E; Parrish, C C

    2002-03-01

    Histochemical and biochemical effects of Toxaphene on liver were investigated in laboratory-bred female and male juvenile yellowtail flounder (Pleuronectes ferrugineus). Fish were fed uncontaminated food, or food contaminated with hexane (the solvent for Toxaphene) or with one of two concentrations of Toxaphene (0.02 or 0.2 microg/g fish/day) for 2 weeks. Males were more advanced in sexual maturity than females, although all were from the same year-class (0(+)). Liver tissue examined histochemically (Sudan black B, oil red O) revealed that Toxaphene affected storage of total and neutral lipids according to sex and dose. The sexes differed in the amount of total and neutral lipids. Neutral lipid droplets were considerably larger in the liver of females. Lipids were extracted and analyzed using the latroscan TLC/FID system. Triacylglycerols comprised the majority of lipids. Animals exposed to the lowest concentration of Toxaphene stored low amounts of total and neutral lipids and high amounts of polar lipids, while animals exposed to a 10 times higher concentration showed the reverse. Sterols were highest in animals exposed to the highest dose. Thus Toxaphene can alter the lipid composition in the liver of yellowtail flounder, which may have consequences for physiological processes involving the liver, such as lipid metabolism and reproduction.

  16. Transcriptomic responses of European flounder (Platichthys flesus) liver to a brominated flame retardant mixture.

    PubMed

    Williams, Tim D; Diab, Amer M; Gubbins, Matt; Collins, Catherine; Matejusova, Iveta; Kerr, Rose; Chipman, James K; Kuiper, Raoul; Vethaak, A Dick; George, Stephen G

    2013-10-15

    Male European flounder (Platichthys flesus) were exposed to a technical mixture of brominated diphenyl ethers (PDBEs, DE-71, Pentamix) that had been purified to remove contaminating dioxins. Controls were exposed to carrier solvent alone. Fish were exposed to decadally increasing concentrations of Pentamix via both sediment and spiked food. The GENIPOL P. flesus cDNA microarray, differentially expressed gene profiling (DEG) and quantitative PCR were employed to detect hepatic transcriptional differences between exposed fish and controls. Gene transcriptional changes were more sensitive to Pentamix exposure than biomarkers measured previously. Pentamix exposure induced transcripts coding for enzymes of xenobiotic metabolism (CYP1A, aldo-keto reductases) and elicited endocrine disruption (vitellogenin and thyroid hormone receptor alpha), with effects on CYP1A and VTG occurring at the highest exposure. Ontology analysis clearly showed dose-responsive changes indicative of oxidative stress, induction of mitochondrial dysfunction, and apoptosis. We conclude that exposure to PBDEs in both sediment and food has a significant adverse effect on a broad range of crucial biochemical processes in the livers of this widely distributed estuarine fish species, the flounder.

  17. Plasma steroid hormone levels in female flounder Platichthys flesus and the influence of fluctuating hydrostatic pressure.

    PubMed

    Damasceno-Oliveira, A; Fernández-Durán, B; Gonçalves, J; Couto, E; Canário, A V M; Coimbra, J

    2012-11-01

    The reproductive cycle in teleosts is timed to guarantee that eggs hatch in the right place at the right time, with environmental factors playing important roles in entraining and controlling the entire process. The effects of some environmental factors, like temperature and photoperiod, are now well understood. There are only a few studies regarding the effects of hydrostatic pressure (HP) on the reproductive cycle, in spite of its importance as a ubiquitous factor in all biological environments and affecting all living organisms. Hydrostatic pressure is of particular importance in fish because they can also experience rapid and cyclic changes in HP due to vertical movements in the water column. The aim of the present research was to investigate the effects of vertical migrations on the reproductive steroids of maturing female flounder. After a 14 day exposure to cyclic hydrostatic pressure (with a period of 12.4h and with a maximum peak of 800 kPa of absolute hydrostatic pressure), fish showed significantly lower plasmatic concentrations of "5β,3α" steroids, metabolites of the putative maturation-inducing steroid in flounder (17α,20β-dihydroxy-4-pregnen-3-one). Results indicate that environmentally realistic cyclic changes of hydrostatic pressure can influence the metabolism of reproductive steroids. This suggests a physiological role of tidally-associated vertical migrations, affecting oocyte maturation and retarding the reproductive cycle in this species until the spawning ground is attained.

  18. A ranking system for the evaluation of intersex condition in European flounder (Platichthys flesus).

    PubMed

    Bateman, Kelly S; Stentiford, Grant D; Feist, Stephen W

    2004-12-01

    Intersex (ovotestis) is the condition whereby an individual possesses oocytes, at varying degrees of severity, within the normal testicular tissue and is regarded as an endpoint of endocrine disruption in male fish. The occurrence of intersex has been linked with exposure to endocrine-disrupting compounds present in the environment, which are thought to mimic the actions of the female sex hormone 17-beta-oestradiol. Using stained histological sections of archived cases of intersex from European flounder (Platichthys flesus), this study developed a grading method to assess the extent of the condition. This was termed the ovotestis severity index (OSI). The OSI utilizes the distribution pattern (focal, diffuse, cluster, zonal) and type of oocyte (previtellogenic, cortical alveolar, vitellogenic) to assign a severity rating to each intersex fish. A high OSI refers to fish with testicular material almost completely replaced with mature (vitellogenic) oocytes, and lower scores indicate those fish with small numbers of immature (previtellogenic) oocytes. The development of this index provides pathologists with a robust tool for the grading of the intersex condition in European flounder and potentially in other fish species.

  19. Evidence for nitric oxide role in the caudal neurosecretory system of the European flounder, Platichthys flesus.

    PubMed

    Marley, Richard; Lu, Weiqun; Balment, Richard J; McCrohan, Catherine R

    2007-01-01

    A neuromodulatory role for nitric oxide has been reported for magnocellular neuroendocrine cells in mammalian hypothalamus. We examined its potential as a local intercellular messenger in the neuroendocrine Dahlgren cell population of the caudal neurosecretory system (CNSS) of the euryhaline flounder. Immunocytochemistry using an antibody raised against human neuronal nitric oxide synthase (NOS) indicated the presence of NOS in the Dahlgren cells. Quantitative RT-PCR, using a flounder-specific probe, revealed NOS mRNA expression in the CNSS. In July, though not in September, NOS mRNA expression was significantly higher in fish fully adapted to seawater, compared to freshwater-adapted fish. Following acute transfer of fish from freshwater to seawater, NOS mRNA expression was elevated at 8h and then recovered by 24h. In pharmacological experiments in vitro, application of NO donors (SNAP, SNP) caused an increase in electrical activity (firing frequency) of Dahlgren cells, recruitment of previously silent cells, together with a greater proportion of cells showing phasic (irregular) activity. The NOS substrate, l-arginine, led to increased firing frequency, cell recruitment and enhanced bursting activity. However, this effect was not blocked by the NOS inhibitor L-NAME. These findings suggest that NO acts as a modulator within the CNSS, potentially enhancing electrical activity and hence secretory output. A role in supporting adaptation to hyperosmotic conditions is also indicated.

  20. Molecular responses of European flounder (Platichthys flesus) chronically exposed to contaminated estuarine sediments.

    PubMed

    Williams, Tim D; Davies, Ian M; Wu, Huifeng; Diab, Amer M; Webster, Lynda; Viant, Mark R; Chipman, J Kevin; Leaver, Michael J; George, Stephen G; Moffat, Colin F; Robinson, Craig D

    2014-08-01

    Molecular responses to acute toxicant exposure can be effective biomarkers, however responses to chronic exposure are less well characterised. The aim of this study was to determine chronic molecular responses to environmental mixtures in a controlled laboratory setting, free from the additional variability encountered with environmental sampling of wild organisms. Flounder fish were exposed in mesocosms for seven months to a contaminated estuarine sediment made by mixing material from the Forth (high organics) and Tyne (high metals and tributyltin) estuaries (FT) or a reference sediment from the Ythan estuary (Y). Chemical analyses demonstrated that FT sediment contained significantly higher concentrations of key environmental pollutants (including polycyclic aromatic hydrocarbons (PAHs), chlorinated biphenyls and heavy metals) than Y sediment, but that chronically exposed flounder showed a lack of differential accumulation of contaminants, including heavy metals. Biliary 1-hydroxypyrene concentration and erythrocyte DNA damage increased in FT-exposed fish. Transcriptomic and (1)H NMR metabolomic analyses of liver tissues detected small but statistically significant alterations between fish exposed to different sediments. These highlighted perturbance of immune response and apoptotic pathways, but there was a lack of response from traditional biomarker genes. Gene-chemical association annotation enrichment analyses suggested that polycyclic aromatic hydrocarbons were a major class of toxicants affecting the molecular responses of the exposed fish. This demonstrated that molecular responses of sentinel organisms can be detected after chronic mixed toxicant exposure and that these can be informative of key components of the mixture.

  1. Bioaccumulation of polybrominated diphenyl ethers (PBDEs) in flounder (Platichthys flesus) in the southern Baltic Sea.

    PubMed

    Waszak, Ilona; Dabrowska, Henryka; Góra, Agnieszka

    2012-08-01

    Concentrations of seven polybrominated diphenyl ether (PBDE) congeners were examined in flounder (Platichthys flesus) and sediment in three southern Baltic Sea sites, representing a range of exposure conditions, in order to evaluate spatial differences in PBDE contamination. Additionally, PBDEs were measured in muscle, liver, and gonads of flounder from one of the sites in order to examine inter-tissue distribution. Mean muscle Σ(7)PBDE levels, in the range of 10-21 ng g(-1) lipid, showed inter-site differences attributed to the distance from the Gulf of Gdańsk, and were overall lower than reported earlier in herring, sprat, and salmon. Biota sediment accumulation factors (BSAFs) for Σ(7)PBDE and individual BDE congeners, in the range of 0.5-24.5, were generally consistent with predicted models for persistent hydrophobic halogenated contaminants. Wet weight (wet wt) PBDE levels in muscle and liver, but not in gonads, were related to tissue lipid content and did not correlate with the fish length and weight. These tissues differed in PBDE levels and profiles as a result of varying lipid content and presumably lipid composition and congener-specific physico-chemical properties.

  2. Stoichiometry and Na+ binding cooperativity of rat and flounder renal type II Na+-Pi cotransporters.

    PubMed

    Forster, I C; Loo, D D; Eskandari, S

    1999-04-01

    The stoichiometry of the rat and flounder isoforms of the renal type II sodium-phosphate (Na+-Pi) cotransporter was determined directly by simultaneous measurements of phosphate (Pi)-induced inward current and uptake of radiolabeled Pi and Na+ in Xenopus laevis oocytes expressing the cotransporters. There was a direct correlation between the Pi-induced inward charge and Pi uptake into the oocytes; the slope indicated that one net inward charge was transported per Pi. There was also a direct correlation between the Pi-induced inward charge and Na+ influx; the slope indicated that the influx of three Na+ ions resulted in one net inward charge. This behavior was similar for both isoforms. We conclude that for both Na+-Pi cotransporter isoforms the Na+:Pi stoichiometry is 3:1 and that divalent Pi is the transported substrate. Steady-state activation of the currents showed that the Hill coefficients for Pi were unity for both isoforms, whereas for Na+, they were 1.8 (flounder) and 2.5 (rat). Therefore, despite significant differences in the apparent Na+ binding cooperativity, the estimated Na+:Pi stoichiometry was the same for both isoforms.

  3. Diel feeding patterns and daily food intake of juvenile stone flounder Platichthys bicoloratus

    NASA Astrophysics Data System (ADS)

    Tomiyama, Takeshi; Katayama, Satoshi; Yamamoto, Masayuki; Shoji, Jun

    2016-01-01

    Pleuronectid flatfish are considered visual day feeders, but their ability to feed at night has not been examined in the field. Juvenile (age-0) stone flounder Platichthys bicoloratus were collected, and their stomach contents were investigated in situ every 4 h over a 24-h period in an estuarine habitat to elucidate diel feeding periodicity. The weight of juvenile stomach contents was usually the highest around dusk and the main prey was bivalve siphons. To reveal whether juveniles feed only at particular times during the day or throughout a 24-h period, we conducted 24-h cage experiments in which 10 juveniles with empty stomachs were held in a cage for approximately 4 h (six trials). This experiment was carried out three times during different moon phases. Juveniles primarily ingested prey during the day, but 30% of fish that were caged at night also ingested prey. The number of successful captures by the caged fish was much greater during the day than that at night. These results indicate that stone flounder generally feed during the day and they may only feed at night under unusual situations, although they have the ability to capture prey at night. The mean daily ration estimated by diel changes in stomach content weight varied from 3.4% (95% confidence interval, 1.8-4.8%) to 13.2% (11.0-15.6%) of body weight between survey dates, indicating that daily food consumption by fish estimated from a single survey may be strongly biased.

  4. Cyclic volatile methylsiloxane bioaccumulation in flounder and ragworm in the Humber Estuary.

    PubMed

    Kierkegaard, Amelie; van Egmond, Roger; McLachlan, Michael S

    2011-07-15

    Cyclic volatile methylsiloxanes are being subjected to regulatory scrutiny as possible PBT chemicals. The investigation of bioaccumulation has yielded apparently contradictory results, with high laboratory fish bioconcentration factors on the one hand and low field trophic magnification factors on the other. In this study, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were studied along with polychlorinated biphenyls (PCBs) in sediments, ragworm, and flounder from six sites in the Humber Estuary. Bioaccumulation was evaluated using multimedia bioaccumulation factors (mmBAFs) which quantified the fraction of the contaminant present in the aquatic environment that is transferred to the biota. PCB 180, a known strongly bioaccumulative chemical, was used as a benchmark. The mean mmBAF of D5 was about twice that of PCB 180 in both polycheates and flounder, while for D4 it was 6 and 14 times higher, respectively. The mmBAF of D6 was a factor 5-10 lower than that of PCB180. The comparatively strong multimedia bioaccumulation of D4 and D5, even in the absence of biomagnification, was explained by both compounds having a >100 times stronger tendency to partition into lipid rather than into organic carbon, while PCB 180 partitions to a similar extent into both matrices.

  5. Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus)

    PubMed Central

    Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

    2015-01-01

    The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot. PMID:26556346

  6. Modeling the changes in the concentration of aromatic hydrocarbons from an oil-coated gravel column

    NASA Astrophysics Data System (ADS)

    Jung, Jee-Hyun; Kang, Hyun-Joong; Kim, Moonkoo; Yim, Un Hyuk; An, Joon Geon; Shim, Won Joon; Kwon, Jung-Hwan

    2015-12-01

    The performance of a lab-scale flow-through exposure system designed for the evaluation of ecotoxicity due to oil spills was evaluated. The system simulates a spill event using an oil-coated gravel column through which filtered seawater is passed and flows into an aquarium containing fish embryos of olive flounder ( Paralichthys olivaceus) and spotted sea bass ( Lateolabrax maculates). The dissolved concentrations of individual polycyclic aromatic hydrocarbons (PAHs) in the column effluent were monitored and compared with theoretical solubilities predicted by Raoult's law. The effluent concentrations after 24 and 48 h were close to the theoretical predictions for the higher molecular weight PAHs, whereas the measured values for the lower molecular weight PAHs were lower than predicted. The ratios of the concentration of PAHs in flounder embryos to that in seawater were close to the lipid-water partition coefficients for the less hydrophobic PAHs, showing that equilibrium was attained between embryos and water. On the other hand, 48 h were insufficient to attain phase equilibrium for the more hydrophobic PAHs, indicating that the concentration in fish embryos may be lower than expected by equilibrium assumption. The results indicate that the equilibrium approach may be suitable for less hydrophobic PAHs, whereas it might overestimate the effects of more hydrophobic PAHs after oil spills because phase equilibrium in an oil-seawater-biota system is unlikely to be achieved. The ecotoxicological endpoints that were affected within a few days are likely to be influenced mainly by moderately hydrophobic components such as 3-ring PAHs.

  7. pol-miR-731, a teleost miRNA upregulated by megalocytivirus, negatively regulates virus-induced type I interferon response, apoptosis, and cell cycle arrest

    PubMed Central

    Zhang, Bao-cun; Zhou, Ze-jun; Sun, Li

    2016-01-01

    Megalocytivirus is a DNA virus that is highly infectious in a wide variety of marine and freshwater fish, including Japanese flounder (Paralichthys olivaceus), a flatfish that is farmed worldwide. However, the infection mechanism of megalocytivirus remains largely unknown. In this study, we investigated the function of a flounder microRNA, pol-miR-731, in virus-host interaction. We found that pol-miR-731 was induced in expression by megalocytivirus and promoted viral replication at the early infection stage. In vivo and in vitro studies revealed that pol-miR-731 (i) specifically suppresses the expression of interferon regulatory factor 7 (IRF7) and cellular tumor antigen p53 in a manner that depended on the integrity of the pol-miR-731 complementary sequences in the 3′ untranslated regions of IRF7 and p53, (ii) disrupts megalocytivirus-induced Type I interferon response through IRF7, (iii) inhibits megalocytivirus-induced splenocyte apoptosis and cell cycle arrest through p53. Furthermore, overexpression of IRF7 and p53 abolished both the inhibitory effects of pol-miR-731 on these biological processes and its stimulatory effect on viral replication. These results disclosed a novel evasion mechanism of megalocytivirus mediated by a host miRNA. This study also provides the first evidence that a virus-induced host miRNA can facilitate viral infection by simultaneously suppressing several antiviral pathways. PMID:27311682

  8. Complete Genome Sequence and Immunoproteomic Analyses of the Bacterial Fish Pathogen Streptococcus parauberis▿†

    PubMed Central

    Nho, Seong Won; Hikima, Jun-ichi; Cha, In Seok; Park, Seong Bin; Jang, Ho Bin; del Castillo, Carmelo S.; Kondo, Hidehiro; Hirono, Ikuo; Aoki, Takashi; Jung, Tae Sung

    2011-01-01

    Although Streptococcus parauberis is known as a bacterial pathogen associated with bovine udder mastitis, it has recently become one of the major causative agents of olive flounder (Paralichthys olivaceus) streptococcosis in northeast Asia, causing massive mortality resulting in severe economic losses. S. parauberis contains two serotypes, and it is likely that capsular polysaccharide antigens serve to differentiate the serotypes. In the present study, the complete genome sequence of S. parauberis (serotype I) was determined using the GS-FLX system to investigate its phylogeny, virulence factors, and antigenic proteins. S. parauberis possesses a single chromosome of 2,143,887 bp containing 1,868 predicted coding sequences (CDSs), with an average GC content of 35.6%. Whole-genome dot plot analysis and phylogenetic analysis of a 60-kDa chaperonin-encoding gene and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH)-encoding gene showed that the strain was evolutionarily closely related to Streptococcus uberis. S. parauberis antigenic proteins were analyzed using an immunoproteomic technique. Twenty-one antigenic protein spots were identified in S. parauberis, by reaction with an antiserum obtained from S. parauberis-challenged olive flounder. This work provides the foundation needed to understand more clearly the relationship between pathogen and host and develops new approaches toward prophylactic and therapeutic strategies to deal with streptococcosis in fish. The work also provides a better understanding of the physiology and evolution of a significant representative of the Streptococcaceae. PMID:21531805

  9. Cytochrome P4501A indices as biomarkers of contaminant exposure: A field study with plaice and flounder

    SciTech Connect

    Eggens, M.; Opperhuizen, A.

    1995-12-31

    Samples of two flatfish species, flounder (Platichthys flesus) and plaice (Pleurnectus platessa), were collected during August/September 1991 and May/June 1992 in the southern North Sea. The induction of hepatic cytochrome P4501A1 (CYP1A) in both species was examined, when exposed to environmental PCBs and PAHs. CYP1A was measured by a semi-quantitative ELISA technique and by the activity of its catalyst, 7-ethoxyresorufin O-deethylase (EROD). In plaice, both hepatic CYP1 protein level and EROD activity were significantly higher at offshore sampling locations than at coastal locations, by a factor of 1.5 to 2. In flounder, which were only collected at coastal locations, the range of values of EROD activity was much greater than in plaice, but the range in CYP1A protein content was comparable in both species. multiple regression analysis of data from plaice and flounder did not show any significant correlation between CYP1A indices, water temperature and contaminant concentrations in fish tissues. CYP1A indices also appeared to be unrelated to food type, as determined by visual screening of fish intestines. It is concluded that the induction of CYP1A in plaice and flounder from the southern North Sea is not related in a simple manner to exposure to PCBs and PAHs. From the point of view-of use as a biomarker, the measurement of CYP1A protein level and EROD activity in plaice and flounder from the open North Sea cannot be applied straightforwardly for monitoring exposure to PCBs and/or PAHs.

  10. Fecundity regulation in relation to habitat utilisation of two sympatric flounder (Platichtys flesus) populations in the brackish water Baltic Sea

    NASA Astrophysics Data System (ADS)

    Nissling, Anders; Thorsen, Anders; da Silva, Filipa F. G.

    2015-01-01

    Two populations of flounder (Platichtys flesus) with different life history traits inhabit the brackish water Baltic Sea. Both types share feeding areas in coastal waters during summer-autumn but utilise different habitats for spawning in spring, namely offshore spawning with pelagic eggs and coastal spawning with demersal eggs respectively. Fecundity regulation by atresia was assessed as prevalence (portion of fish with atresia) and intensity (calculated as the average intensity of atresia in these fish) during the reproductive cycle following start of gonad development in the autumn up to spawning in spring, and evaluated in relation to fish condition (Fulton's condition factor reflecting energy reserves of the fish) and feeding incidence of the respective population. Peaking in winter (December-February), fecundity regulation was significantly higher for coastal spawning flounder than for flounder spawning offshore. For coastal spawners, the prevalence was 45-90% with an intensity of 6.4-9.3% vs. 0-25% and an intensity of 2.1-3.4% for offshore spawners during winter. Further, fecundity regulation ceased prior to spawning for offshore spawners but continued for coastal spawners. For coastal spawners, the prevalence was 12-29% and an intensity of 2.5-6.1% during spawning. The change in fish condition was strongly related to feeding incidence and differed between populations. As feeding ceased, condition of offshore spawners decreased during winter up to spawning, whereas condition of coastal spawners decreased during autumn but was maintained as feeding started again prior to spawning. Thus, habitat utilisation according to spawning strategy affects the timing of fecundity down-regulation reflecting availability of resources, namely limited food resources in deep areas and higher availability in coastal areas. Offshore spawning flounder display characteristics typical for a capital spawner with ceasing of feeding and oocyte down-regulation well before spawning

  11. Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology

    PubMed Central

    El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M.; El-Ewasy, Sara M.

    2015-01-01

    Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology. PMID:26180806

  12. Optimization of Culture Conditions for Production of the Anti-Leukemic Glutaminase Free L-Asparaginase by Newly Isolated Streptomyces olivaceus NEAE-119 Using Response Surface Methodology.

    PubMed

    El-Naggar, Noura El-Ahmady; Moawad, Hassan; El-Shweihy, Nancy M; El-Ewasy, Sara M

    2015-01-01

    Among the antitumor drugs, bacterial enzyme L-asparaginase has been employed as the most effective chemotherapeutic agent in pediatric oncotherapy especially for acute lymphoblastic leukemia. Glutaminase free L-asparaginase producing actinomycetes were isolated from soil samples collected from Egypt. Among them, a potential culture, strain NEAE-119, was selected and identified on the basis of morphological, cultural, physiological, and biochemical properties together with 16S rRNA sequence as Streptomyces olivaceus NEAE-119 and sequencing product (1509 bp) was deposited in the GenBank database under accession number KJ200342. The optimization of different process parameters for L-asparaginase production by Streptomyces olivaceus NEAE-119 using Plackett-Burman experimental design and response surface methodology was carried out. Fifteen variables (temperature, pH, incubation time, inoculum size, inoculum age, agitation speed, dextrose, starch, L-asparagine, KNO3, yeast extract, K2HPO4, MgSO4·7H2O, NaCl, and FeSO4·7H2O) were screened using Plackett-Burman experimental design. The most positive significant independent variables affecting enzyme production (temperature, inoculum age, and agitation speed) were further optimized by the face-centered central composite design-response surface methodology.

  13. Involvement of host recognition by oncomiracidia and post-larval survivability in the host specificity of Heterobothrium okamotoi (Monogenea: Diclidophoridae).

    PubMed

    Ohhashi, Yu; Yoshinaga, Tomoyoshi; Ogawa, Kazuo

    2007-01-01

    Heterobothrium okamotoi, a monogenean gill parasite, shows high host specificity for tiger puffer, Takifugu rubripes. In the present study, in vivo and in vitro experimental infections were conducted using various fish species, including T. rubripes, to understand the mechanisms of specificity. In in vivo experiments, T. rubripes, grass puffer, Takifugu niphobles, olive flounder, Paralichthys olivaceus, and red sea bream, Pagrus major, were exposed to oncomiracidia of H. okamotoi labelled with a fluorescent dye, 5- (and -6) carboxyfluorescein diacetate succinimidyl ester, and the numbers of parasites on the gills and skin were recorded at intervals. Oncomiracidia were attached to gills and skin of all the experimental fish species immediately after exposure, and the infection intensity on T. rubripes was higher than that on T. niphobles and much higher than those on the other two species. After 2 days, the attached parasites remained on the gills of T. rubripes, but disappeared from the other hosts. During in vitro experiments, gill filaments excised from seven different fish species (four fish species used in the in vivo experiments and panther puffer, Takifugu pardalis, southern flounder, Paralichthys lethostigma and spotted halibut, Verasper variegates) were exposed to oncomiracidia and the attachment to each fish species and subsequent larval behaviour was observed. The percentage of post-larvae that attached to T. rubripes was slightly higher than those which attached to congeneric fish species and much higher than those of non-tetraodontid fish species. In vivo and in vitro experiments demonstrated that oncomiracidia of H. okamotoi have an affinity for their natural host, T. rubripes, and congeneric fish species. The disappearance of attached post-larvae from 'alien' hosts within 2 days during in vivo experiments suggested that host recognition by oncomiracidia and subsequent post-larval survivability are involved in the host specificity of H. okamotoi.

  14. The European flounder (Platichthys flesus) TP53 functions as a temperature-sensitive transcription factor which inhibits cell growth in yeast.

    PubMed

    Cachot, J; Flaman, J M; Frébourg, T; Leboulenger, F

    2004-01-07

    Numerous studies focus on biological roles of the TP53 tumor suppressor gene in mammals but little is known about the actual function of TP53 in lower vertebrates. In this study, we used an in vivo functional assay in yeast to address the transactivation capacity of the flounder TP53 protein. We showed that the flounder TP53 acts as a sequence-specific transcription factor which is able to transactivate various human promoters containing a p53-responsive element (RE). This transcriptional activity was completely abrogated in the Val147Glu TP53 mutant previously identified in two flounder hepatic hyperplasia. In addition, we showed that the wild-type (wt) flounder TP53 but not the Val147Glu mutant inhibits cell growth when expressed in yeast. We finally reported that transcription regulation and growth inhibition by the wild-type flounder TP53 is temperature-dependent. The flounder TP53 optimal temperature appeared lower than those reported for the Xenopus and human homologues.

  15. Frequency of hepatocellular fibrillar inclusions in European flounder (Platichthys flesus) from the Douro River estuary, Portugal.

    PubMed

    Carrola, João; Fontaínhas-Fernandes, António; Pires, Maria João; Rocha, Eduardo

    2014-02-01

    Liver lesions in wild fish have been associated with xenobiotic exposure. Facing reports of pollution in the Douro River estuary (north of Portugal), we have been making field surveys using fishes and targeting histopathological biomarkers of exposure and effect. Herein, we intended to better characterize and report the rate of one poorly understood lesion-hepatocellular fibrillar inclusions (HFI)-found in European flounder (Platichthys flesus). With this report, we aimed to establish sound baseline data that could be viewed as a starting point for future biomonitoring, while offering the world's second only pool of field data on such a liver toxicopathic lesion, which could be compared with data available from the UK estuaries. Sampling was done in the Douro River estuary over 1 year. A total of 72 animals were fished with nets, in spring-summer (SS) and autumn-winter (AW) campaigns. Livers were processed for histopathology and both routine and special staining procedures (alcian blue, periodic acid Schiff (PAS), tetrazonium coupling reaction). Immunohistochemistry targeted AE1/AE3 (pan cytokeratins). The severity of the HFI extent was graded using a system with four levels, varying from 0 (absence of HFI) to 3 (high relative density of cells with HFI). Cells (isolated/groups) with HFI appeared in 35 % or more of the fish, in the total samples of each season, and over 40 % in more homogeneous sub-samples. There were no significant differences when comparing samples versus sub-samples or SS versus AW. When merging the data sets from the two seasons, the frequency of fish with HFI was ≈36 % for the total sample and ≈49 % for the sub-sample. The extreme group (biggest and smallest fish) revealed a HFI frequency of only 16 %, which differed significantly from the total and sub-sampled groups. Immunostaining and PAS were negative for the HFI, and alcian blue could, at times, faintly stain the inclusions. These were positive with the tetrazonium reaction. We showed

  16. Histopathological lesions and DNA adducts in the liver of European flounder (Platichthys flesus) collected in the Seine estuary versus two reference estuarine systems on the French Atlantic coast.

    PubMed

    Cachot, Jérôme; Cherel, Yan; Larcher, Thibaut; Pfohl-Leszkowicz, Annie; Laroche, Jean; Quiniou, Louis; Morin, Jocelyne; Schmitz, Julien; Burgeot, Thierry; Pottier, Didier

    2013-02-01

    An epidemiological survey was conducted in the Seine estuary and in two smaller and relatively preserved estuaries on the French Atlantic coast in order to estimate the occurrence of liver lesions in European flounder, Platichthys flesus, and also to seek putative risk factors for the recorded pathologies. Four hundred and seventy-eight fish of both sexes and of different size ranges were sampled in the three studied areas, 338 of which in the Seine estuary. All fish were examined for histopathological liver lesions, while DNA adducts and otoliths were analyzed on a subsample. Five categories of hepatic lesions were recorded with the following prevalence for the Seine estuary: 36.7 % inflammations, 8 % parasites (mainly encysted nematodes), 6.5 % foci of cellular alteration (FCA), 5.3 % foci of necrosis or regeneration (FNR), and 1.5 % tumors. Inflammation occurrence increased according to age, contrary to parasitic infestations and FCA which were more prevalent in young fish, notably those of <1 year old (group 0). Tumors were only observed in females of more than two winters. Females exhibited a higher prevalence of tumors (3.0 %) and FCA (6.5 %) than males (0 and 2.6 %, respectively). Parasitic and infectious lesions and FNR were equally distributed in males and females. The prevalence of FNR was also shown to vary according to sampling season, with significantly more occurrences of liver necrosis in the fish collected in summer than in spring. Spatial differences were observed with a higher occurrence of encysted parasites in flounders from the upper Seine estuary, while inflammations predominated in flounders living downstream. Temporal trends were also noted, with an increased prevalence of parasitic infestations, inflammations, and FCA in the 2002-2003 period in comparison to the 1996-1997 one. The three flounder populations from the Seine estuary (Normandy), Ster estuary (Brittany), and Bay of Veys (Normandy) showed different spectra of hepatic lesions

  17. Organochlorine contaminants in flounder (Platichthys flesus) and mullet (Mugil cephalus) from Douro estuary, and their use as sentinel species for environmental monitoring.

    PubMed

    Ferreira, M; Antunes, P; Gil, O; Vale, C; Reis-Henriques, M A

    2004-09-20

    In order to monitor the presence of organic pollutants in Douro estuary (NW Portugal), two sentinel fish species, grey mullet (Mugil cephalus) and flounder (Platichthys flesus), were periodically sampled from May 2001 to April 2002. At all sampling periods, several specimens of both species were allowed to depurate in clean sea water. Levels of PCBs and DDTs were quantified in liver and muscle of both species. The accumulation of PCBs was higher in muscle of mullet, with a maximum of 345 ng/g dw, than in flounder, with a maximum 52ng/g dw. In the liver, flounder showed the highest levels (811 ng/g dw). Of the 18 congeners analysed, CBs 180 (hepta), 153 and 138 (hexachlorobiphenyls) were predominant in the tissue of both species. The maximum concentration of tDDT was measured in flounder liver (301ng/g dw). In contrast, a 10-fold higher tDDT was recorded in mullet muscle (63-69 ng/g dw and 8-16 ng/g dw for mullet and flounder, respectively). The hepatic ethoxyresorufin O-deethylase (EROD) activity was periodically determined. Consistently, a 10-fold higher enzymatic activity was present in mullet in comparison with flounder (1536 pmol/min/mg protein in mullet and 156 pmol/min/mg protein in flounder). In mullet, no correlation could be found between EROD activity and gonado-somatic index (GSI) or hepato-somatic index (HSI). On the contrary, during the reproductive season, female flounder showed a negative correlation between EROD activity and GSI. Despite being in clean sea water for 1 month period, no significant decrease in the tissue content of PCBs and tDDT was found. However, mullet's EROD activity followed a clear pattern, with a decrease enzymatic activity after being in captivity. Female flounder displayed a similar trend during the resting season. Yet, during the reproductive season, an increased EROD activity was recorded after being in captivity for 1 month, which may be associated with a modulation effect of steroids on CYP 1A1. Histological analyses of

  18. Effects of cyclic hydrostatic pressure on the brain biogenic amines concentrations in the flounder, Platichthys flesus.

    PubMed

    Damasceno-Oliveira, Alfredo; Fernández-Durán, Begoña; Gonçalves, José; Serrão, Paula; Soares-da-Silva, Patrício; Reis-Henriques, Maria Armanda; Coimbra, João

    2007-01-01

    The present study evaluated the effects of cyclic variations of hydrostatic pressure (HP) on neurotransmitters in the whole brain of flounder. The concentrations of the biogenic amines L-3,4-dihydroxyphenylalanine (L-DOPA), dopamine (DA), norepinephrine (NE), epinephrine (E), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), 3-methoxytyramine (3-MT), 5-hydroxytryptamine (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) were measured. Fish were subjected to HP cyclic variations which mimic naturally occurring conditions for a period of 14 days. DA, NE and 5-HT concentrations were significantly smaller by 21, 24 and 36%, respectively, compared to control fish. The concentrations of monoamine metabolites HVA, 3-MT and 5-HIAA were also smaller than those in control fish. These results suggest that central monoaminergic systems were influenced during long exposure to cyclic HP. The decreases of central neurotransmitters content might be involved in the physiological and behavioral responses to intermittent HP in fish.

  19. Variation in hepatic aryl hydrocarbon hydroxylase activity in flounder, Platichthys flesus: A baseline study

    NASA Astrophysics Data System (ADS)

    Tarlebø, J.; Solbakken, J. E.; Palmork, K. H.

    1985-06-01

    This investigation is concerned with the natural variations in aryl hydrocarbon hydroxylase (AHH) activity of flounder ( Platichthys flesus L.) throughout the year. A general trend towards higher activity in males was observed. It became significant during gonadal maturation, a period during which the activity in females was inhibited. Addition of α-naphthoflavone inhibited AHH activity except in females with maturing gonads. Enzyme activity measured at the optimal temperature for incubation showed highest activity during spring followed by a significant decrease during summer. Activity increased again during autumn, followed by a second decrease in the winter season. When activity was calculated based on ambient water temperature at time of sampling, smaller fluctuations between different seasons were observed; the only significant variation was high activity in June. The results obtained indicate that AHH activity is affected by both exogenous and endogenous factors, which should be taken into consideration if AHH activity is used as a biological indicator of marine pollution effects.

  20. Ice-binding structure and mechanism of an antifreeze protein from winter flounder.

    PubMed

    Sicheri, F; Yang, D S

    1995-06-01

    Antifreeze proteins provide fish with protection against the freezing effect of polar environments by binding to ice surfaces and inhibiting growth of ice crystals. We present the X-ray crystal structure at 1.5 A resolution of a lone alpha-helical antifreeze protein from winter flounder, which provides a detailed look at its ice-binding features. These consist of four repeated ice-binding motifs, the side chains of which are inherently rigid or restrained by pair-wise side-chain interactions to form a flat binding surface. Elaborate amino- and carboxy-terminal cap structures are also present, which explain the protein's rich alpha-helical content in solution. We propose an ice-binding model that accounts for the binding specificity of the antifreeze protein along the <0112> axes of the (2021) ice planes.

  1. Characterization of parameters for in vitro culture of isolated ovarian follicles of greenback flounder Rhombosolea tapirina.

    PubMed

    Pankhurst, N W; Riple, G

    2000-10-01

    Isolated ovarian follicles of greenback flounder Rhombosolea tapirina were incubated with a variety of gonadotropins (GtHs) and steroid precursors for periods of up to 42 h, and levels of free and glucuronated testosterone (T) and 17beta-estradiol (E(2)) in the medium, and free T and E(2) from inside follicles were measured by RIA. Short incubations (6 h) generated increases in T and E(2) in response to steroid precursors, but not human chorionic GtH (hCG), or salmon or carp GtH. At incubation times of 18 h, all GtHs stimulated T and, or E(2) production, whereas after 42-h incubation, GtH effects on E(2) production had disappeared. Steroid precursors remained effective at 18 and 42 h. T and E(2) glucuronides were formed in small quantities but did not account for loss of treatment effects at long incubation times. Instead, this could be explained by accumulation of E(2) in controls as a result of continued basal steroid production. Follicles absorbed substantial amounts of both endogenous and exogenous steroid from the medium, however, this did not appear to have any influence on changes in treatment effects with incubation time. Flounder follicles were most sensitive to hCG, followed by salmon and carp GtH at approximately 10-fold higher concentrations. Ovarian segments were not sensitive to any GtH but did convert exogenous steroid precursors indicating that tissue access by GtH may be a limiting factor under certain in vitro conditions. HCG augmented the conversion of 17-hydroxyprogesterone (17P) to T but not T to E(2), consistent with the relative GtH-insensitivity of aromatase in other species. Follicles converted a range of steroid precursors with equal competence, indicating that no step in the cleavage pathway is strongly rate-limited, and that choice of precursor is unlikely to affect the assessment of steroidogenic activity.

  2. Juvenile nursery colonization patterns for the European flounder (Platichthys flesus): A latitudinal approach

    NASA Astrophysics Data System (ADS)

    Martinho, Filipe; van der Veer, Henk W.; Cabral, Henrique N.; Pardal, Miguel A.

    2013-11-01

    In this work, we analysed the latitudinal trends in the nursery habitat colonization processes of the European flounder (Platichthys flesus). This was accomplished by estimating the duration of the pelagic and metamorphic stages, as well as the duration of the spawning period, in several nursery areas across its geographical distribution range in the European Atlantic Coast: Mondego estuary (Portugal), Vilaine estuary (France), Slack estuary (France), Wadden Sea (Netherlands) and the Sørfjord (Norway). All juvenile flounders were captured with beam trawls in June/July 2010, and otolith microstructure was used to determine the duration of each stage by means of daily growth increments. The pelagic and metamorphic stages were longer at the middle of the distribution range, and lasted in total up to two months after hatching. The spawning period occurred between mid-January and early-July over the species' distribution range, with a time lapse of nearly two months between the Mondego estuary and the Sørfjord, as a consequence of warmer water temperature earlier in the season in southern areas. In general, total length of the captured fish showed a latitudinal cline between the northernmost and southernmost sampling sites, with higher values at the middle of the distribution range. The results also suggested the existence of a countergradient growth compensation mechanism in the northernmost populations. Apart from temperature, which sets the general metabolic pace of organisms, differences between sites were also related with local features, such as the extension of the continental platform and adaptations to transport and retention mechanisms.

  3. Transport Velocity of Flounder Larvae ( Platichthys flesus L.) in the Dollard (Ems Estuary)

    NASA Astrophysics Data System (ADS)

    Jager, Z.; Mulder, H. P. J.

    1999-09-01

    Larval concentrations of flounder (Platichthys flesus L.), longitudinal current velocity and physical variables were measured simultaneously in the Dollard to calculate the mass transport of the larvae, salinity and suspended matter. Transport velocities of the three substances (salinity, suspended matter and larvae) and of water were calculated and compared. The concept of larval velocity was extended to incorporate the effect of varying vertical larval distribution. The contributions of variations in vertical and temporal concentration to the transport velocity were calculated separately. The differences in velocity between the substances in relation to the vertical and temporal variation provide more insight in estuarine transport processes in the nursery. Temporal salinity variation dominated over vertical variation during flood, and indicated that longitudinal advection was important. Overall, during flood the transport velocity of salinity was 3% lower than that of water. During ebb, there was hardly any difference between the transport velocity of salinity and water. The contributions of temporal and vertical variation in suspended matter were each in the order of 10%, but of opposite signs. The net result is a transport velocity of suspended matter which is 3% (flood) or 4% (ebb) higher than that of water. Erosion-deposition seemed the dominant process. During flood, transport velocity of larvae is 9% higher than that of water, which is mainly caused by vertical concentration variation (6%), while during ebb, larval transport velocity is 9% lower, which is almost exclusively due to the temporal concentration variation (8%). Swimming influences transport during flood, while during ebb it is not clear which process dominates. The results indicate that flounder larvae make use of selective tidal stream transport inside the nursery.

  4. Biomarkers of contaminant exposure: results of a field study with flounder (Platichthys flesus) from the southern Baltic Sea.

    PubMed

    Napierska, Dorota; Podolska, Magdalena

    2005-07-01

    The results of the present study are based on enzyme biomarker measurements in flounder (Platichthys flesus), a flatfish species that is widely distributed in Baltic coastal waters. The fish were collected from known pollution gradients and from reference areas regarded as relatively free of anthropogenic input. Muscular cholinesterases (ChEs), hepatic glutathione S-transferase (GST), and hepatic ethoxyresorufin-O-deethylase (EROD) activities were measured in each sampled specimen of flounder. Generalized linear models (GLM) were used to analyze the dependence of the enzyme activity on sampling year and area as well as on the biological parameters of the fish. Statistically significant differences in the activities of the measured biomarkers were observed between reference and contaminated sites. ChEs and GST activities differed with gender. The results of this study suggest that the location and year of sampling have a significant impact on the activity of all the measured biomarkers.

  5. Assessment of juvenile flounder catches at the cordemais power station water intake in the Loire estuary, France

    NASA Astrophysics Data System (ADS)

    Robin, Jean-Paul

    A comprehensive sampling exercise was carried out at Cordemais Power Station during 1988 in order to evaluate the number of 0-group flounder, Platichthys flesus, removed from the Loire Estuary by the water intakes. Larvae drawn through the cooling system and juveniles impinged on the drumscreens were both taken into account. Statistical confidence limits of the estimates (which are useful for comparisons with the effect of other human activities) were estimated using non-linear regression and Monte-Carlo techniques. The method was developed for one of the two similar units working during the April-June period of high flounder abundance in the cooling water. For this unit 16.5 million fish were drawn through the cooling system and 1.13 million were trapped on the drumscreen. The effect of the Power Station is discussed in connection with small-meshed fisheries and assessments of the estuarine juvenile stock.

  6. Comparison of biomarker and pathological responses in flounder (Platichthys flesus L.) induced by ingested polycyclic aromatic hydrocarbon (PAH) contamination.

    PubMed

    Reynolds, W J; Feist, S W; Jones, G J; Lyons, B P; Sheahan, D A; Stentiford, G D

    2003-08-01

    This study investigated the response of biomarker measurements and histopathological indicators of polycyclic aromatic hydrocarbon (PAH) exposure in the flounder (Platichthys flesus L.). Flounder were fed food spiked with a mixture of four PAHs at an environmentally relevant range of concentrations for either one or six months. Ethoxyresorufin-O-deethylase (EROD) activity was elevated following 1 month exposure to PAH concentrations up to 50 mgkg(-1) in food. Bile metabolite concentrations were found to increase with PAH concentration, up to 500 mgkg(-1) PAH. By comparison, no DNA adducts were detected and there were no significant histopathological changes observed. After 6 months exposure, EROD levels were not elevated but bile metabolites showed a similar dose dependent relationship as in the 1 month experiment, while DNA adducts were only detected in the highest PAH exposure groups. No significant histopathological changes were observed. The results are discussed with respect to the implications for the use of these methods in environmental monitoring studies.

  7. Food and feeding habits of juvenile flounder Platichthys flesus (L.), abd turbot Scophthalmus maximus L. in the åland archipelago, northern Baltic Sea

    NASA Astrophysics Data System (ADS)

    Aarnio, Katri; Bonsdorff, Erik; Rosenback, Nina

    1996-12-01

    The food choice of juvenile flounder ( Platichthys flesus) and turbot ( Scophthalmus maximus) was studied in the northern Baltic Sea during the years 1988, 1989, 1994 and 1995. The diet included organisms from 30 species/taxa in flounder (n = 306) and 10 species/taxa in turbot (n = 41). Flounder ⩽ 45 mm mainly consumed meiofauna (dominating taxon: Harpacticoida, Copepoda) and larger fish (46-101 mm) consumed macrofauna (dominating taxa: Oligochaeta, Amphipoda and Chironomidae). In terms of biomass, macrofauna dominated for all sizes of flounders, and meiofauna was important only for the smallest fish. A strong seasonal variation could be detected in the diet. In spring, macrofauna dominated for all size classes of fish (only fish > 30 mm were caught in spring), while in summer and autumn meiofauna dominated the diets for fish ⩽ 45 mm in size. Juvenile turbot (22-88 mm) consumed macrofauna and small fish. Turbot ⩽ 30 mm consumed mainly amphipods, while > 30 mm turbot consumed mysid shrimps, amphipods and fish. The ontogenetic shift from meio- to macrofauna-sized prey in flounders occurs at a larger fish size in the northern Baltic Sea than reported in other areas, possibly depending on the increased relative importance of meiofauna in the northern Baltic. The seasonal variation in the diet could be due to seasonally changing abundances in the zoobenthos, or for the small fish (1-group, spring), to switching from meio- to macrofauna in order to optimize their energy gain. The 0-group flounders consumed meiofauna for a long period, possibly due to a learning-process or simply due to easy availability of meiofauna. Turbot has a much larger mouth gap than flounders, thus allowing them to consume macrofauna from the beginning of their benthic life.

  8. Biomarker responses in flounder Platichthys flesus from the Polish coastal area of the Baltic Sea and applications in biomonitoring.

    PubMed

    Napierska, Dorota; Barsiene, Janina; Mulkiewicz, Ewa; Podolska, Magdalena; Rybakovas, Aleksandras

    2009-10-01

    The objective of this study was to investigate the pattern of enzymatic activities, environmental genotoxicity and cytotoxicity in flounder, Platichthys flesus, from the Polish coastal area of the Baltic Sea. Fish were sampled in different contaminated sites in the Gulf of Gdansk and in a reference area outside the gulf. The activities of acetylcholinesterase (AChE), glutathione S: -transferase (GST), catalase (CAT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), were studied, as well as the frequency of micronuclei, nuclear buds and fragmented-apoptotic cells. A higher mean activity level of muscular AChE and a lower activity level of hepatic GST were evident in samples taken from the reference site, relative to those found in the gulf. Modeled CAT activity (in both liver and gill tissue), blood plasma LDH and CK activities were all significantly higher in flounder collected at locations within the Gulf of Gdansk than at the reference site. No statistically significant alterations were observed in the activities of ALT and AST in the blood plasma of flounder in this study. Fish collected from a location at the mouth of the Vistula River showed the highest hepatic GST and CAT, the highest gill CAT activity, and the highest frequency of blood micronuclei, nuclear buds and fragmented-apoptotic cell inductions, as well as the lowest level of blood plasma CK. The present study confirms that compared to fish from the reference area, flounder from the Gulf of Gdansk clearly demonstrate a different enzyme activity, genotoxicity and cytotoxicity biomarker response pattern.

  9. Characterization of genes encoding prolactin and prolactin receptors in starry flounder Platichthys stellatus and their expression upon acclimation to freshwater.

    PubMed

    Noh, Gyeong Eon; Lim, Han Kyu; Kim, Jong-Myoung

    2013-04-01

    This study aims to investigate the genes encoding prolactin (PRL) and prolactin receptors (PRLR) and their tissue-specific expression in starry flounder Platichthys stellatus. Starry flounder PRL gene consisting of five exons encodes an ORF of 212 amino acid residue comprised of a putative signal peptide of 24 amino acids and a mature protein of 188 amino acids. It showed amino acid identities of 73 % with tuna Thunnus thynnus, 71 % with black porgy Acanthopagrus schlegelii, 69 % with Nile tilapia Oreochromis niloticus, 64 % with pufferfish Takifugu rubripes, 63 % with rainbow trout Oncorhynchus mykiss, and 60 % with mangrove rivulus Kryptolebias marmoratus. Phylogenetic analysis of piscine PRLs also demonstrated a similarity between starry flounder and other teleosts but with a broad distinction from non-teleost PRLs. PRLR gene consists of eight exons encoding a protein of 528 amino acid residues. It showed a similarity to the PRLR2 subtype as reflected by amino acid identities of 54 % with A. schlegelii, 48.1 % with K. marmoratus, 46.3 % with tilapia O. mossambicus, and 46.1 % with O. niloticus PRLR2 as compared to PRLR1 isoform having less than 30 % identities. While mRNA transcript corresponding to PRL was detected only from the pituitary, most of PRLR mRNA was detected in the gill, kidney, and intestine, with a small amount in the ovary. The level of PRL transcript progressively increased during 6 days of acclimation to freshwater and then decreased but stayed higher than that of seawater at 60 days of acclimation. An opposite pattern of changes including a decrease at the beginning of the acclimation but a slight increase in the level osmolality was found as adaptation continued. The results support the osmoregulatory role of PRL signaling in starry flounder.

  10. Molecular Response of Estuarine Fish to Hypoxia: A Comparative Study with Ruffe and Flounder from Field and Laboratory

    PubMed Central

    Tiedke, Jessica; Thiel, Ralf; Burmester, Thorsten

    2014-01-01

    On a global scale, the frequencies and magnitudes of hypoxic events in coastal and estuarine waters have increased dramatically over the past 20 years. Fish populations are suitable indicators for the assessment of the quality of aquatic ecosystems, as they are omnipresent and often comprise a variety of different lifestyles and adaption strategies. We have investigated on the molecular level the impact of hypoxia on two fish species typical of European estuaries. We monitored the expression of eleven putatively hypoxia-responsive genes by means of quantitative real-time RT-PCR in brains, gills and hearts of the ruffe (Gymnocephalus cernua) and the flounder (Platichthys flesus). We first investigated the effect of naturally occurring hypoxia in the Elbe estuary. In a second approach, expression changes in the response to hypoxia were monitored under controlled laboratory conditions. The genes that showed the strongest effect were two respiratory proteins, myoglobin and neuroglobin, as well as the apoptosis enzyme caspase 3. As previously observed in other fish, myoglobin, which was considered to be muscle-specific, was found in brain and gills as well. Comparison of field and laboratory studies showed that – with the exception of the heart of flounder – that mRNA levels of the selected genes were about the same, suggesting that laboratory conditions reflect natural conditions. Likewise, trends of gene expression changes under hypoxia were the same, although hypoxia response was more pronounced in the Elbe estuary. In general, the flounder displayed a stronger response to hypoxia than the ruffe, suggesting that the flounder is more susceptible to hypoxia. The most pronounced differences were found among tissues within a species, demonstrating that hypoxia response is largely tissue-specific. In summary, our data suggest that laboratory experiments essentially mimic field data, but additional environmental factors enhance hypoxia response in nature. PMID:24595439

  11. Winter flounder (Pseudopleuronectes americanus) estuarine habitat use and the association between spring temperature and subsequent year class strength

    NASA Astrophysics Data System (ADS)

    Wilber, Dara H.; Davis, David; Clarke, Douglas G.; Alcoba, Catherine J.; Gallo, Jenine

    2013-11-01

    Winter flounder habitat use in New York/New Jersey Harbor was examined through a long-term (2002-2010) bottom trawl sampling program (Aquatic Biological Survey) in which 5234 winter flounder were captured in 2069 samples collected at approximately 26 stations throughout the harbor. Interannual variability in catch-per-unit-effort (CPUE) primarily was attributable to fluctuations in Year-1 juvenile CPUE, which was positively correlated with total annual egg abundances from the previous year. Adult male CPUE during the spawning season was positively correlated with total egg abundances of the same year, whereas adult female CPUE was unrelated to annual egg abundances in the harbor. Annual variation in adult male densities in the harbor during the spawning season reflects the intensity of estuarine spawning activity, whereas adult female densities may include non-reproductive, foraging individuals. Seasonal fluctuations in condition indices reflected energy use during the spawning season, with relatively high condition in January, reduced levels in March and April, and elevated condition again in May. Adult CPUE peaked in April, coincident with the critical feeding period that follows spawning. Mean April water temperatures were positively correlated with egg abundances the following year and Year-1 juvenile CPUE two years later. A similar correlation between April temperatures and Year-1 juvenile abundances two years later was demonstrated using published data for winter flounder collected in Niantic Bay, CT. Higher April water temperatures may enhance benthic secondary production during the critical feeding period, and thus increase prey availability for foraging adults that need to restore energy reserves in order to reproduce the following year. A direct examination of benthic secondary production and variation in winter flounder estuarine foraging and subsequent spawning activity is needed to more fully understand this relationship.

  12. Postprandial acid-base balance and ion regulation in freshwater and seawater-acclimated European flounder, Platichthys flesus.

    PubMed

    Taylor, Josi R; Whittamore, Jonathan M; Wilson, Rod W; Grosell, Martin

    2007-08-01

    The effects of feeding on both acid-base and ion exchange with the environment, and internal acid-base and ion balance, in freshwater and seawater-acclimated flounder were investigated. Following voluntary feeding on a meal of 2.5-5% body mass and subsequent gastric acid secretion, no systemic alkaline tide or respiratory compensation was observed in either group. Ammonia efflux rates more than doubled from 489 +/- 35 and 555 +/- 64 mumol kg(-1) h(-1) under control conditions to 1,228 +/- 127 and 1,300 +/- 154 mumol kg(-1) h(-1) post-feeding in freshwater and seawater-acclimated fish, respectively. Based on predictions of gastric acid secreted during digestion, we calculated net postprandial internal base gains (i.e., HCO (3) (-) secreted from gastric parietal cells into the blood) of 3.4 mmol kg(-1) in seawater and 9.1 mmol kg(-1 )in freshwater-acclimated flounder. However, net fluxes of ammonia, titratable alkalinity, Na(+) and Cl(-) indicated that branchial Cl(-)/HCO (3) (-) and Na(+)/H(+) exchange played minimal roles in counteracting these predicted base gains and cannot explain the absence of alkaline tide. Instead, intestinal Cl(-)/HCO (3) (-) exchange appears to be enhanced after feeding in both freshwater and seawater flounder. This implicates the intestine rather than the gills as a potential route of postprandial base excretion in fish, to compensate for gastric acid secretion.

  13. Abnormally elevated VTG concentrations in flounder (Platichthys flesus) from the Mersey estuary (UK)--a continuing problem.

    PubMed

    Kleinkauf, Anne; Scott, Alexander P; Stewart, Christie; Simpson, Michael G; Leah, Richard T

    2004-07-01

    Vitellogenin (VTG) plasma concentrations were measured in flounder (Platicthys flesus L.) caught in two neighbouring UK estuaries between autumn 1997 and summer 2000. As found in previous studies, male and immature female flounder that were caught in the Mersey, but not in the Dee, had abnormally elevated concentrations of VTG in their plasma-evidence of the presence of natural and synthetic estrogens and/or xenoestrogens in the Mersey. The present study reveals a marked seasonal cycle in VTG concentrations in males. In late spring and summer, male flounder in the Mersey have relatively low concentrations of VTG (microg mL(-1) range). However, in mid-winter, mean concentrations were as high as 5 mg mL(-1). There is also evidence that there was a lessening in the degree of estrogenic endocrine disruption between 1996-1997 (the period of the initial studies on the Mersey) and 1998-2000 (the period covered by the present study). Only 0.5% of the fish contained ovotestes (intersex condition).

  14. Biomarker responses in flounder (Platichthys flesus) and mussel (Mytilus edulis) in the Klaipeda-Būtinge area (Baltic Sea).

    PubMed

    Barsiene, Janina; Lehtonen, Kari K; Koehler, Angela; Broeg, Katja; Vuorinen, Pekka J; Lang, Thomas; Pempkowiak, Janusz; Syvokiene, Janina; Dedonyte, Veronika; Rybakovas, Aleksandras; Repecka, Rimantas; Vuontisjärvi, Heta; Kopecka, Justyna

    2006-01-01

    During the EU project BEEP a battery of biomarkers was applied in flounder (Platichthys flesus) and the blue mussel (Mytilus edulis) collected at three locations off the Lithuanian coast (Baltic Sea) in June and September 2001 and 2002. The elevated biomarker responses in specimens sampled in September 2001 were apparently related to the extensive dredging activities in the Klaipeda port area and subsequent dumping of contaminated sediments. High concentrations of organic pollutants (organochlorines and PBDEs) were also measured in the tissues of both indicator species. In addition, response levels of genotoxicity, cytotoxicity, immunotoxicity as well as concentrations of PAH metabolites in the bile of flounder showed elevations in 2002 after an oil spill in the Būtinge oil terminal in November 2001. In flounder, biomarker measurements 10 months after the spill indicated recovery processes but in mussels a high level of genotoxicity could still be observed 22 months later. The present study illustrates the usefulness of the multi-biomarker approach in the detection of biological effects of pollution in this region of the Baltic Sea.

  15. Oxidative stress response of European flounder (Platichthys flesus) to cadmium determined by a custom cDNA microarray.

    PubMed

    Sheader, Derek L; Williams, Timothy D; Lyons, Brett P; Chipman, J Kevin

    2006-07-01

    The monitoring of the impact of chemical pollutants upon marine ecosystems commonly employs a multi-biomarker approach. Functional genomics, using cDNA microarrays, allows for a comprehensive view of how an organism is responding to an exposure, with respect to changes in gene expression. Differentially expressed mRNAs were first isolated from livers of European flounder by means of suppressive, subtractive hybridisation. A clone set containing a total of 284 different potentially differentially expressed mRNAs was produced, of which 84 were tentatively identified. These were combined with previously cloned known stress genes isolated by degenerate PCR to produce a custom 500-clone microarray platform with each clone arrayed to four spots. Subsequent array experiments using cadmium-treated flounder detected up-regulation of 27 transcripts, including Cu/Zn superoxide dismutase, thioredoxin, a peroxiredoxin and a glutathione-S-transferase, reflecting oxidative stress in exposed flounder, while CYP1A expression was down-regulated. These changes were confirmed by real-time PCR. The array experiment highlighted a number of candidate genes for further analysis as potential novel biomarkers of cadmium exposure and demonstrated the applicability of the custom microarray approach in the study of the effects of toxicants.

  16. Temporal and spatial variations of selected biomarker activities in flounder (Platichthys flesus) collected in the Baltic proper.

    PubMed

    Kopecka, Justyna; Pempkowiak, Janusz

    2008-07-01

    The aim of the study was to examine temporal (monthly) and spatial changes in the activities of a battery of biomarkers and evaluate the influence of gender and environmental factors on those activities. Abiotic factors not correlated with chemical pollution-water temperature, salinity, and oxygen concentration-were evaluated. The activities of the following biomarkers-muscular ChEs (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)), hepatic ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST) and catalase (CAT), and gross indices-condition factor (CF), hepatosomatic index (HSI), and gonadosomatic index (GSI)-were measured in individual flounder Platichthys flesus. Female flounder were collected once a month from April 2003 to April 2004 at Sobieszewo (Gulf of Gdańsk). In December 2003 flounder of both sexes from nine stations in the Baltic Proper were caught and tested. Strong monthly (attributed mainly to spawning, and less-to pollution) and geographical (attributed to pollution) variations in biomarker activities, as well as gender differences, were demonstrated. Correlations between the enzymes with the abiotic properties of the environment were less important.

  17. Sequence and organization of the complete mitochondrial genomes of spotted halibut (Verasper variegatus) and barfin flounder (Verasper moseri).

    PubMed

    He, Chongbo; Han, Jiabo; Ge, Longli; Zhou, Zunchun; Gao, Xianggang; Mu, Yunlei; Liu, Weidong; Cao, Jie; Liu, Zhanjiang

    2008-06-01

    In this work, the mitochondrial genomes for spotted halibut (Verasper variegatus) and barfin flounder (Verasper moseri) were completely sequenced. The entire mitochondrial genome sequences of the spotted halibut and barfin flounder were 17,273 and 17,588 bp in length, respectively. The organization of the two mitochondrial genomes was similar to those reported from other fish mitochondrial genomes containing 37 genes (2 rRNAs, 22 tRNAs and 13 protein-coding genes) and two non-coding regions (control region (CR) and WANCY region). In the CR, the termination associated sequence (ETAS), six central conserved block (CSB-A,B,C,D,E,F), three conserved sequence blocks (CSB1-3) and a region of 61-bp tandem repeat cluster at the end of CSB-3 were identified by similarity comparison with fishes and other vertebrates. The tandem repeat sequences show polymorphism among the different individuals of the two species. The complete mitochondrial genomes of spotted halibut and barfin flounder should be useful for evolutionary studies of flatfishes and other vertebrate species.

  18. Accumulation and effects of nodularin from a single and repeated oral doses of cyanobacterium Nodularia spumigena on flounder (Platichthys flesus L.).

    PubMed

    Vuorinen, Pekka J; Sipiä, Vesa O; Karlsson, Krister; Keinänen, Marja; Furey, Ambrose; Allis, Orla; James, Kevin; Perttilä, Ulla; Rimaila-Pärnänen, Eija; Meriluoto, Jussi A O

    2009-07-01

    Nodularin (NODLN) is a cyclic pentapeptide hepatotoxin produced by the cyanobacterium Nodularia spumigena, which occurs regularly in the Baltic Sea during the summer season. In this study flounder (Platichthys flesus L.) was orally exposed to NODLN either as a single dose or as three repeated doses 3 days apart. Liver and bile samples of the fish were taken 4 days after the last dose. Liver glutathione-S-transferase (GST) activity was also measured and the histopathology of the liver was investigated. The liver of the exposed fish was analyzed by liquid chromatography-mass spectrometry for NODLN concentration. The content of NODLN-like compounds in the bile was analyzed by enzyme-linked immunosorbent assay. NODLN exposure caused slightly incoherent liver architecture and degenerative cell changes in both groups. The mean liver GST activity was significantly higher in the repeatedly dosed flounders than in the singly dosed flounders or in the control. In conclusion, the significantly lower NODLN concentration and the increased GST activity in the liver of the repeatedly dosed flounders compared to the singly dosed flounders suggest that NODLN is rapidly detoxificated. The absence of NODLN glutathione conjugates and the low concentrations of NODLN-like compounds in the bile indicate that detoxification products disintegrate or they are rapidly excreted.

  19. Clonal xenobiotic resistance during pollution-induced toxic injury and hepatocellular carcinogenesis in liver of female flounder (Platichthys flesus (L.)).

    PubMed

    Koehler, Angela; Alpermann, Tilmann; Lauritzen, Bjarne; Van Noorden, Cornelis J F

    2004-01-01

    Juvenile and adult female flounder (Platichthys flesus (L.)) were caught either in the estuary of the most polluted European river, the Elbe, or as controls in a reference site to study pollution-induced xenobiotic resistance in their livers in relation to pathological alterations. In juvenile fish, livers displayed reversible and irreversible degenerative toxipathic lesion types but never showed (pre)neoplastic changes. Tumour frequencies up to 70% were found macroscopically in livers of adult female flounder which had progressed to adenomas and carcinomas in the most polluted site. Because male adult flounder show only up to 50% of livers containing early preneoplastic foci but never malignancies, we focussed our study on female individuals. (Pre)neoplastic changes ranged from early eosinophilic foci to basophilic foci, adenomas and hepatocellular carcinomas. Adenomas were generally eosinophilic whereas carcinomas were mainly basophilic. These phenotypical sequential changes strongly resemble those found in chemically-induced liver carcinogenesis in mammals. Characteristic mutations known from mammalian cancers have not been found so far in these flounder livers. Therefore, we investigated whether epigenetic events had induced a metabolic "resistant phenotype" of (pre)malignant cancer cells during hepatocellular carcinogenesis. With a quantitative immunohistochemical approach, we studied expression of P-glycoprotein (P-gp)-mediated multixenobiotic resistance (MXR), cytochrome P4501A1, glutathione-S-transferase-A which are key proteins in xenobiotic metabolism and elimination. Glucose-6-phosphate dehydrogenase (G6PDH) activity, the major source of the reducing power NADPH which is needed for biotransformation, oxyradical scavenging and biosynthesis, was detected as well. We observed upregulation of G6PDH activity already in early preneoplastic eosinophilic foci and subsequent further upregulation in basophilic foci and carcinomas. P-gp started to become

  20. Metabolism, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) in relation to fish size and temperature

    NASA Astrophysics Data System (ADS)

    Fonds, M.; Cronie, R.; Vethaak, A. D.; Van Der Puyl, P.

    Daily rates of oxygen consumption, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) have been measured in the laboratory at various constant temperatures. Oxygen consumption was related to body weight of the fish as a power function, with a weight exponent of between 0.71 and 0.85. No significant effects of temperature or feeding on this exponent were found. Flounder showed a significantly higher metabolic rate and a higher temperature coefficient for metabolism than plaice. Maximum daily rates of food consumption and the weight increment of fish fed with excess rations of fresh mussel meat could also be related to fish weights by means of power functions. For plaice these exponents decreased from about 0.9 at low temperatures (2-6 C°) to about 0.7 at high temperatures (18-22°C). Such a temperature effect on the weight exponent indicates that small juvenile fish eat more and grow faster at higher temperatures than do large older fish, and that large fish do better at low temperatures. After scaling of daily food consumption and growth in proportion to metabolic weights of the fish (W 0.78), feeding and growth at different fish sizes and temperatures can be compared and temperature-growth rate models can be used for investigations of feeding in natural populations. Compared to plaice, young flounder ate more and grew faster at higher temperatures (> 14°C). This may partly explain the preference of flounder for the shallower parts of coastal areas and estuaries, where summer temperatures and food densities are higher. Energy budgets of young plaice and flounder fed with excess rations of mussel meat indicate that at least 29% of the food energy is used for metabolism while about 37% of the food energy is converted into growth. The net conversion efficiency was estimated at 0.45 for food and growth in units of ash-free dry weight, and at 0.53 for food and growth in energy units. Analysis of the energy budget showed

  1. Population ecology and habitat preferences of juvenile flounder Platichthys flesus (Actinopterygii: Pleuronectidae) in a temperate estuary

    NASA Astrophysics Data System (ADS)

    Souza, Allan T.; Dias, Ester; Nogueira, Ana; Campos, Joana; Marques, João C.; Martins, Irene

    2013-05-01

    The European flounder Platichthys flesus is a widely distributed epibenthic species and an important component of demersal fish assemblages in the European Atlantic coastal waters. In Portuguese estuaries, this species reaches high densities, especially in Minho estuary (NW Iberian Peninsula, Europe), potentially playing an important role in the system's ecology. In this context, the population structure, production and the habitat use of juvenile P. flesus were investigated. Sampling took place monthly, from February 2009 until July 2010 along the entire estuarine gradient (5 sampling stations distributed in the first 29 km from the river mouth, with S1 located near the river mouth, S2 inside a salt marsh, S3 in a salinity transition zone, while S4 and S5 were located in the upper estuary). Flounder's density varied significantly among sampling stations and seasons (two-way PERMANOVA: p < 0.001), with the majority of the individuals being found during the spring (30.1%) and in S3 and S4 (72.6%). Males and females presented an even distribution, with a higher proportion of males observed during summer. Fish length also differed among sampling stations and seasons (two-way PERMANOVA: p < 0.001), with larger fishes being found in S1 during the autumn (168.50 ± 59.50 mm) and the smallest in S4 during the spring (33.80 ± 3.12 mm). Size classes associated differently with environmental variables, with larger juveniles being more abundant in the downstream areas of the estuary, whereas smaller juveniles were related to higher water temperatures, suggesting a habitat segregation of P. flesus of different sizes. The fish condition of P. flesus in Minho estuary was higher than in other systems, probably due to the dominance of juveniles on the population. Also, the densities found in this estuary were up to 32 times higher than in other locations, suggesting that Minho estuary is an important nursery area for the species. The estimated secondary production of P. flesus

  2. Histopathological effects of chronic aqueous exposure to bis(tri-n-butyltin)oxide (TBTO) to environmentally relevant concentrations reveal thymus atrophy in European flounder (Platichthys flesus).

    PubMed

    Grinwis, G C M; Wester, P W; Vethaak, A D

    2009-10-01

    Although the use of tributyltin in antifouling paints has been banned, this compound is still a serious pollutant of the marine environment. This paper describes a unique study in which European flounder (Platichthys flesus) were chronically (8 months) exposed to bis(tri-n-butyltin)oxide (TBTO) in the water under controlled laboratory conditions. Residue levels in selected tissues (liver, muscle) and general health status indices were measured and the effects on several organs (gills, liver, mesonephros, ovary/testis, spleen, and gastrointestinal tract) were examined histopathologically. Additionally, morphometric analysis of the thymus was performed. The major finding is that exposure of flounder to 5 microg TBTO/l over a period of 8 months, resulting in body burdens comparable to high field levels, induced significant reduction of thymus volume, possibly affecting immunocompetence of the animals. Chronic exposure of European flounder to tributyltin is therefore likely to affect the general health status of this species in heavily polluted aquatic environments.

  3. Measurements of biomarker levels in flounder (Platichthys flesus) and blue mussel (Mytilus trossulus) from the Gulf of Gdańsk (southern Baltic).

    PubMed

    Kopecka, Justyna; Lehtonen, Kari K; Barsiene, Janina; Broeg, Katja; Vuorinen, Pekka J; Gercken, Jens; Pempkowiak, Janusz

    2006-01-01

    In the framework of the EU funded BEEP project a set of biomarkers, gross morphometric indices and tissue concentrations of selected organic pollutants were measured in flounder (Platichthys flesus) and mussels (Mytilus trossulus) collected twice a year (April and October) from three sites in the inner Gulf of Gdańsk between autumn 2001 and spring 2003. In flounder, seasonal differences in most biomarkers were observed, but no correlations with tissue pollutant levels could be found. In mussels, highly variable levels in biomarker responses were seen, but no clear seasonal or spatial trends, directly related to tissue concentrations, could be established. The observed biomarkers distribution the study sites are probably mostly caused by interannual, seasonal and individual variability and, in case of flounder, possibly by exchange of stocks between the sampling sites.

  4. Metal concentrations, growth and condition indices in European juvenile flounder (Platichthys flesus) relative to sediment contamination levels in four Eastern English Channel estuaries.

    PubMed

    Henry, F; Filipuci, I; Billon, G; Courcot, L; Kerambrun, E; Amara, R

    2012-12-01

    The aim of the present study was to evaluate the effects of metal contamination on the biological responses of 0-group juvenile European flounder and to assess and compare the quality of four estuarine habitats located in the Eastern English Channel. Fish otolith growth and condition indices (RNA : DNA ratio, Fulton's K condition index) were measured and found to be significantly lower in individuals from the Seine estuary compared to those of the Canche, Authie and Somme estuaries. No obvious effects of hydrological condition or food availability on the flounder biological responses were observed. Sediments from the Seine showed the highest metal concentrations, bioavailable proportion and enrichment factors. Higher metal concentrations were observed in fish from the Seine compared to the other ones caught in less polluted estuaries. These results suggest that contaminants may have a negative impact on the early life history stage of flounder.

  5. Application of a food chain model to polychlorinated biphenyl contamination of the lobster and winter flounder food chains in New Bedford Harbor

    SciTech Connect

    Connolly, J.P. Manhattan Coll., Riverdale, NY )

    1991-04-01

    As part of a Remedial Investigation/Feasibility Study for the New Bedford Harbor Superfund site a model of polychlorinated biphenyls (PCBs) in the lobster and winter flounder food chains was developed. This model successfully reproduces tri-, tetra-, penta-, and hexachlorobiphenyl concentrations observed at all levels of the food chain and across the 2 order of magnitude concentration gradient in the system. The model indicated that PCB concentrations in the flounder and, to a lesser extent, in the lobster are derived from the sediment. Dietary uptake exceeds uptake across the gill for all four homologues and becomes the dominant route at the higher chlorinated homologues. The assimilation efficiency of ingested PCB apparently declines from relatively high values for tri-chlorobiphenyl to relatively low values for hexachlorobiphenyl. Differences in observed lobster and flounder PCB concentrations appear to be due to differences in the importance of the benthic component of the food chains of these animals and differences in whole body lipid content.

  6. The effects of fin rot disease and sampling method on blood chemistry and hematocrit measurements of winter flounder, Pseudopleuronectes americanus from New Haven Harbor (1987--1990).

    PubMed

    Ziskowski, J; Mercaldo-Allen, R; Pereira, J J; Kuropat, C; Goldberg, R

    2008-04-01

    Winter flounder from New Haven, Connecticut were evaluated for fin rot disease. Blood samples collected from healthy and diseased fish were used to measure bilirubin, calcium, hematocrit, inorganic phosphorus, osmolality, and total protein. Blood measurements were significantly affected by the presence of fin rot disease and by sampling mode (bled immediately or after 18 h). A reduction in blood chemistry values was associated with fin rot disease. Logistic regression modeling was used to identify explanatory variables contributing to the fin rot outcome in winter flounder. Blood constituent levels were higher in fish bled immediately versus 18 h post-capture, especially among fish without fin rot, suggesting that a waiting period is necessary for blood values to stabilize following initial sampling stress. This study presents evidence that winter flounder blood chemistry and hematocrit measurements are affected by fin rot disease.

  7. Presence of microplastic in the digestive tracts of European flounder, Platichthys flesus, and European smelt, Osmerus eperlanus, from the River Thames.

    PubMed

    McGoran, A R; Clark, P F; Morritt, D

    2017-01-01

    Like many urban catchments, the River Thames in London is contaminated with plastics. This pollutant is recorded on the river banks, in the benthic environment and in the water column. The present study was conducted to assess the extent of microplastic ingestion in two River Thames fish species, the European flounder (Platichthys flesus) and European smelt (Osmerus eperlanus). Samples were collected from two sites in Kent, England; Erith and Isle of Grain/Sheppey, near Sheerness, with the latter being more estuarine. The results revealed that up to 75% of sampled European flounder had plastic fibres in the gut compared with only 20% of smelt. This difference may be related to their diverse feeding behaviours: European flounder are benthic feeders whilst European smelt are pelagic predators. The fibres were predominantly red or black polyamides and other fibres included acrylic, nylon, polyethylene and polyethylene terephthalate and there was no difference in occurrence between the sites sampled.

  8. Responses of the European flounder Platichthys flesus to the chemical stress in estuaries: load of contaminants, gene expression, cellular impact and growth rate.

    PubMed

    Evrard, Estérine; Devaux, Alain; Bony, Sylvie; Burgeot, Thierry; Riso, Ricardo; Budzinski, Hélène; Le Du, Marie; Quiniou, Louis; Laroche, Jean

    2010-03-01

    European flounder responses to the chemical stress were assessed by a comparative approach on four estuaries displaying contrasted patterns of contamination. The contamination typology of the estuaries was investigated by individual measurements of contaminants in fish. Molecular and physiological responses were studied by gene expression, genotoxicity, neurotoxicity and growth rate. Fishes in contaminated estuaries were characterized by high levels of bioaccumulated contaminants, slow energetic metabolism and reduced growth rate, in contrast to the fish responses in the reference site. A seasonal effect was highlighted for contaminated flounder populations, with high PCB levels, high genotoxicity and elevated detoxification rate in summer compared with winter.

  9. Proteomic responses of European flounder to temperature and hypoxia as interacting stressors: Differential sensitivities of populations.

    PubMed

    Pédron, Nicolas; Artigaud, Sébastien; Infante, José-Luis Zambonino; Le Bayon, Nicolas; Charrier, Grégory; Pichereau, Vianney; Laroche, Jean

    2017-02-16

    In the context of global change, ectotherms are increasingly impacted by abiotic perturbations. Along the distribution area of a species, the populations at low latitudes are particularly exposed to temperature increase and hypoxic events. In this study, we have compared the proteomic responses in the liver of European flounder populations, by using 2-D electrophoresis. One southern peripheral population from Portugal vs two northern core populations from France, were reared in a common garden experiment. Most of the proteomic differences were observed between the two experimental conditions, a cold vs a warm and hypoxic conditions. Consistent differentiations between populations were observed in accumulation of proteins involved in the bioenergetics- and methionine-metabolisms, fatty acids transport, and amino-acid catabolism. The specific regulation of crucial enzymes like ATP-synthase and G6PDH, in the liver of the southern population, could be related to a possible local adaptation. This southern peripheral population is spatially distant from northern core populations and has experienced dissimilar ecological conditions; thus it may contain genotypes that confer resilience to climate changes.

  10. "Right" or "wrong"? Insights into the ecology of sidedness in european flounder, Platichthys flesus.

    PubMed

    Russo, Tommaso; Pulcini, Domitilla; Costantini, Daniele; Pedreschi, Debbi; Palamara, Elisa; Boglione, Clara; Cataudella, Stefano; Scardi, Michele; Mariani, Stefano

    2012-03-01

    Sidedness polymorphism in flatfish has been linked to ecological selection between morphs. However, the alternate hypothesis that morphological differences between right- and left-sided forms may be due to errors during development, as a consequence of disturbed homeostasis, which still remains largely unexplored. Here, we examined the case of Platichthys flesus (flounder), a polymorphic flatfish exhibiting large and clinal variation in the frequency of the left-sided morph, which is the reversed condition in this generally right-sided species. An integrated approach consisting of the analyses of shape variation, stomach contents, and skeletal anomalies was used. Morphological differences were observed between morphs, which are in agreement with previous findings in a congeneric species (Platichthys stellatus). In parallel, significant differences in feeding choices were detected, suggesting a coherent association between subtle morphological differences between morphs and their use of trophic resources. Skeletal anomalies and meristic counts did not corroborate the hypothesis that morphometric divergence in reversed individuals may be caused or reinforced by developmental instability.

  11. Physiological response in the European flounder (Platichthys flesus) to variable salinity and oxygen conditions.

    PubMed

    Lundgreen, Kim; Kiilerich, Pia; Tipsmark, Christian K; Madsen, Steffen S; Jensen, Frank B

    2008-09-01

    Physiological mechanisms involved in acclimation to variable salinity and oxygen levels and their interaction were studied in European flounder. The fish were acclimated for 2 weeks to freshwater (1 per thousand salinity), brackish water (11 per thousand) or full strength seawater (35 per thousand) under normoxic conditions (water Po(2) = 158 mmHg) and then subjected to 48 h of continued normoxia or hypoxia at a level (Po(2) = 54 mmHg) close to but above the critical Po(2). Plasma osmolality, [Na(+)] and [Cl(-)] increased with increasing salinity, but the rises were limited, reflecting an effective extracellular osmoregulation. Muscle water content was the same at all three salinities, indicating complete cell volume regulation. Gill Na(+)/K(+)-ATPase activity did not change with salinity, but hypoxia caused a 25% decrease in branchial Na(+)/K(+)-ATPase activity at all three salinities. Furthermore, hypoxia induced a significant decrease in mRNA levels of the Na(+)/K(+)-ATPase alpha1-subunit, signifying a reduced expression of the transporter gene. The reduced ATPase activity did not influence extracellular ionic concentrations. Blood [Hb] was stable with salinity, and it was not increased by hypoxia. Instead, hypoxia decreased the erythrocytic nucleoside triphosphate content, a common mechanism for increasing blood O(2) affinity. It is concluded that moderate hypoxia induced an energy saving decrease in branchial Na(+)/K(+)-ATPase activity, which did not compromise extracellular osmoregulation.

  12. Cortisol and prolactin modulation of caudal neurosecretory system activity in the euryhaline flounder Platichthys flesus.

    PubMed

    Marley, Richard; Lu, Weiqun; Balment, Richard J; McCrohan, Catherine R

    2008-09-01

    Previous studies have shown roles for cortisol and prolactin in osmoregulatory adaptation to seawater and freshwater, respectively, in euryhaline fish. This study of the European flounder investigated the potential for these hormones to modulate activity of the caudal neurosecretory system (CNSS), which is thought to be involved in physiological adaptation to changing external salinity. Superfusion of isolated CNSS with either cortisol or prolactin (10 microM; 15 min) led to changes in firing activity in neuroendocrine Dahlgren cells, recorded extracellularly. Cortisol evoked a modest increase in overall firing activity, with the response delayed by 4 h after treatment. The response to prolactin was short latency, continued to build up over the subsequent 4-h wash period, and comprised increased firing activity together with recruitment of previously silent Dahlgren cells. Immunoreactivity for glucocorticoid and prolactin receptors was localised to Dahlgren cells. The CNSS expression level for glucocorticoid-2 receptor mRNA, measured by Q-PCR, was significantly lower in fish fully acclimated to freshwater, compared to seawater. No differences were seen between these two states for prolactin receptor mRNA expression. These results provide evidence for a modulatory action of both hormones on the neurosecretory function of the CNSS.

  13. Complex movement patterns of greenback flounder (Rhombosolea tapirina) in the Murray River estuary and Coorong, Australia

    NASA Astrophysics Data System (ADS)

    Earl, Jason; Fowler, Anthony J.; Ye, Qifeng; Dittmann, Sabine

    2017-04-01

    The greenback flounder Rhombosolea tapirina is a commercially-important flatfish species in southern Australia and New Zealand, whose population dynamics are poorly understood. Acoustic telemetry was used to assess movement patterns and area use for R. tapirina in the Murray River estuary and Coorong, South Australia. Twenty fish (221-313 mm total length) equipped with acoustic transmitters were monitored for up to seven months during a period of high freshwater inflow. Fish were detected over a large part of the system, but showed a strong preference for brackish and near-marine conditions in the inner estuary. Tagged fish exhibited complex movement patterns that differed among individuals, including: (1) within estuary movements; (2) dispersal from the estuary to the sea; and (3) return migrations between the estuary and the sea. A diurnal shift in fine-scale area use was observed in the part of the estuary where residency was highest, with individuals occupying deeper habitats during the day and shallower areas during the night. The results demonstrate the individualistic and often highly transient behaviour of this species and its ability to undertake regular movements over the spatial scale of 10s of km. Understanding such movement patterns can improve effective management of estuarine flatfish populations and ecosystems.

  14. Polluted harbor sediment and the annual reproductive cycle of the female flounder, Platichthys fiesus (L.)

    SciTech Connect

    Janssen, P.A.H.; Lambert, J.G.D.; Goos, H.J.T.; Wezel, A.P. van; Opperhuizen, A.

    1995-12-31

    Compounds such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs),and pesticides are metabolized by enzyme systems, which are also involved in steroid metabolism. Disturbances of reproduction may therefore occur through the interference of these compounds with the endocrine system. Several aspects of reproduction were studied in the flounder, Platichthys fiesus (L.), an euryhaline flatfish which inhabits coastal waters and is therefore a suitable biomonitor for the effects of chemical pollutants. Fish were kept during three years in mesocosm systems of which the first provided a control, while the second one contained polluted sediment, derived from the Rotterdam harbor. In November, all ovaries from both mesocosms contained vitellogenic oocytes. In May, all the control fish were previtellogenic, while the ovaries of fish from the polluted mesocosm contained, besides previtellogenic oocytes, a large number of vitellogenic oocytes, indicating that an estrogenic induction had occurred. The in vitro tissue incubations with androstenedione as precursor revealed that the ovarian capacity to synthesize testosterone (T), estrone (E{sub 2}) and 17{beta}-estradiol (E{sub 2}) didn`t differ between both mesocosms. In May, however, the levels of T and E{sub 2} as well as the level of the yolk-precursor vitellogenin were significantly higher in the polluted mesocosm. The conclusion from this study was that polluted harbor sediment contains compounds that effect normal reproductive development, i.e. the induction of premature vitellogenesis.

  15. Effects of cooking on levels of PCBs in the fillets of winter flounder

    SciTech Connect

    Posten, T.M.; Durell, G.S.; Moya, J.; Garrahan, K.G.

    1994-12-31

    The consumption of contaminated fish has been shown to be a significant, pathway for human exposure. Risk assessors often assume that humans are exposed to the levels of contaminants in edible tissue of fish measured prior to preparation and cooking. This assumption may lead to overestimation or underestimation of risk since a particular cooking method may remove or transform toxic constituents in the flesh by thermal denaturation, vaporization, dissolution in aqueous tissue fluids or lipids that drip off the flesh, or extraction into cooling oil during deep fat frying. This paper presents and discusses the results of a study conducted to quantify the effect of preparation and cooking on PCB concentrations in the edible portion of winter flounder. The effects of broiling, pan frying, and deep frying in oil were tested on fillets from 21 fish. The change in total PCB concentrations and 18 specific PCB congeners was estimated using a mass-balance approach using the precooked PCB concentration on a wet-weight basis and the cooked concentration taking into account any change in fillet weight resulting from cooking. Deep frying in oil resulted in a 47% reduction in total PCB levels in fillet tissue, while pan frying and broiling did not result in a statistically significant difference in total PCB levels.

  16. Effects of cooking on levels of PCBs in the fillets of winter flounder (Pseudopleuronectes americanus)

    SciTech Connect

    Poston, T.M.; Durell, G.S.; Koczwara, G.; Spellacy, A.M.

    1995-08-01

    The Pacific Northwest Laboratory and Battelle Ocean Sciences performed a study to determine the effect of cooking on polychlorinated biphenyl (PCB) levels in the fillets of winter flounder (Pseudopleuronectes americanus). Broiling, pan frying, and deep frying in oil were tested on fillets from 21 fish collected from New Bedford Harbor, Massachusetts, on February 21, 1991. The evaluation involved estimating the change in PCB concentrations using a mass-balance approach that factored the change in fillet weight resulting from cooking with the changes in PCB concentration expressed on a precooked wet-weight basis. Deep frying in oil resulted in a 47% reduction in total PCB levels in fillet tissue. Additionally, deep frying caused a 40% reduction in fillet mass. Pan frying and broiling resulted in statistically in insignificant increases in total PCB levels of 15% and 17%, respectively. Fillet mass reductions resulting from pan frying and broiling were 7% and 15%, respectively. The effects of cooking on 18 individual congeners generally paralleled the results observed for total PCB. All 18 congeners were significantly reduced by deep frying. Congener Cl{sub 2}(08) also was significantly reduced by either pan frying. Congeners Cl{sub 5}(105) and Cl{sub 5}(118) showed apparent significant increases in concentrations following pan frying. Congeners Cl{sub 5}(105), Cl{sub 5}(118), and C1{sub 6}(138) showed significant increases in concentration following broiling.

  17. Tissue expression and stock variation of isozymes of stone flounder ( Kareius bicoloratus)

    NASA Astrophysics Data System (ADS)

    Xu, Jianpeng; Zhang, Quanqi; Qi, Jie; Wang, Zhigang

    2007-04-01

    Tissue expression and stock variation of isozymes of stone flounder ( Kareius bicoloratus) were analyzed with horizontal starch gel electrophoresis. For the fourteen enzymes assayed, 31 loci were recorded. The results indicated that all the isozymes examined were obviously tissue-specific. The expressions of SOD *, GDH *, G3PDH-2 * and ADH-2 * were detected only in liver, SDH-1 *, MDH-1 * and ADH-1 * only in muscle, and LDH-B * and LDH-C * only in eyes. In comparison, MDH-2 *, GPI-3 * and SDH-2 * were detected in all tissues examined. Other loci examined were detected in a variety of tissues. Muscle and liver were selected to detect the isozyme variation of the two geographic stocks of Qingdao and Weihai, Shandong Province, China. The percentages of polymorphic loci ( P 0.99) were 29.17% and 25.00%, the observed heterozygosities ( H 0) were 0.028 ± 0.014 and 0.040 ± 0.019, and the expected heterozygosities ( He) were 0.039 ± 0.017 and 0.052 ± 0.022 in Qingdao and Weihai stock, respectively. The coefficient of gene differentiation ( F st) and genetic distance ( D) between the two stocks was 0.012 and 0.0011, respectively, indicating that the genetic differentiation is low between them. Compared with other species of Pleuronectiformes, both the percentage of polymorphic loci and the mean heterozygosity of K. bicoloratus were at a middle level.

  18. Impacts of mixtures of herbicides on molecular and physiological responses of the European flounder Platichthys flesus.

    PubMed

    Evrard, Estérine; Marchand, Justine; Theron, Michaël; Pichavant-Rafini, Karine; Durand, Gaël; Quiniou, Louis; Laroche, Jean

    2010-09-01

    The widespread use of pesticides results in a growing contamination of the aquatic environment. The effects of (1) a simple mixture of a glyphosate-based formulation and AMPA (Aminomethylphosphonic acid--a primary metabolite of glyphosate) and of (2) a more complex mixture of herbicides (glyphosate/AMPA/mecoprop/acetochlor/2,4D) were explored on the molecular and physiological responses of the European flounder Platichthys flesus, considering a long-term and environmentally realistic contamination. Molecular responses were identified using suppression subtractive hybridization on liver samples: the level of gene transcription was significantly different between contaminated fishes vs control ones for 532 sequences, after a 62-day contamination. Among them, 222 sequences were identified by homology with data-based sequences; they encoded several metabolic pathways including: methionine and lipid metabolism, immunity, protein regulation, coagulation and energetic metabolism. Expression pattern of nine transcripts in the liver was confirmed by real-time PCR. The molecular study underlined that potential markers of liver injury were expressed for both mixtures, in particular betaine homocysteine methyl transferase and chemotaxin. Physiological responses were analysed considering blood parameters and condition factor; after the two months contamination period; no significant physiological difference was detected between contaminated and control fish.

  19. Intermolecular interaction studies of winter flounder antifreeze protein reveal the existence of thermally accessible binding state.

    PubMed

    Nguyen, Dat H; Colvin, Michael E; Yeh, Yin; Feeney, Robert E; Fink, William H

    2004-10-05

    The physical nature underlying intermolecular interactions between two rod-like winter flounder antifreeze protein (AFP) molecules and their implication for the mechanism of antifreeze function are examined in this work using molecular dynamics simulations, augmented with free energy calculations employing a continuum solvation model. The energetics for different modes of interactions of two AFP molecules is examined in both vacuum and aqueous phases along with the water distribution in the region encapsulated by two antiparallel AFP backbones. The results show that in a vacuum two AFP molecules intrinsically attract each other in the antiparallel fashion, where their complementary charge side chains face each other directly. In the aqueous environment, this attraction is counteracted by both screening and entropic effects. Therefore, two nearly energetically degenerate states, an aggregated state and a dissociated state, result as a new aspect of intermolecular interaction in the paradigm for the mechanism of action of AFP. The relevance of these findings to the mechanism of function of freezing inhibition in the context of our work on Antarctic cod antifreeze glycoprotein (Nguyen et al., Biophysical Journal, 2002, Vol. 82, pp. 2892-2905) is discussed.

  20. Developmental toxicity in flounder embryos exposed to crude oils derived from different geographical regions.

    PubMed

    Jung, Jee-Hyun; Lee, Eun-Hee; Choi, Kwang-Min; Yim, Un Hyuk; Ha, Sung Yong; An, Joon Geon; Kim, Moonkoo

    2017-03-06

    Crude oils from distinct geographical regions have distinct chemical compositions, and, as a result, their toxicity may be different. However, developmental toxicity of crude oils derived from different geographical regions has not been extensively characterized. In this study, flounder embryos were separately exposed to effluents contaminated by three crude oils including: Basrah Light (BLO), Pyrenees (PCO), and Sakhalin Vityaz (SVO), in addition to a processed fuel oil (MFO-380), to measure developmental toxicity and for gene expressions. Each oil possessed a distinct chemical composition. Edema defect was highest in embryos exposed to PCO and MFO-380 that both have a greater fraction of three-ring PAHs (33% and 22%, respectively) compared to BLO and SVO. Observed caudal fin defects were higher in embryos exposed to SVO and MFO-380, which are both dominated by naphthalenes (81% and 52%, respectively). CYP1A gene expressions were also highest in embryos exposed to SVO and MFO-380. Higher incidence of cardiotoxicity and lower nkx 2.5 expression were detected in embryos exposed to PCO. Unique gene expression profiles were observed in embryos exposed to crude oils with distinct compositions. This study demonstrates that crude oils of different geographical origins with different compositional characteristics induce developmental toxicity to different degrees.

  1. Effect of acute restraint on hypothalamic pro-vasotocin mRNA expression in flounder, Platichthys flesus.

    PubMed

    Bond, H; Warne, J M; Balment, R J

    2007-01-01

    Arginine vasotocin (AVT) stimulates release of adenocorticotrophin hormone (ACTH) in trout. However, AVT's role in fish hypothalamic-pituitary-interrenal-axis (HPIA) is not fully understood. Here, we examined distribution of AVT and glucocorticoid receptor (GR) in the magnocellular preoptic nucleus (PM) and the AVT/cortisol response to acute restraint in flounder. The GR/AVT distribution in the PM was determined using double immunohistochemistry (IHC). Flounder were confined in nets, immersed in water for 30m, with plasma and tissue samples taken prior to, 3, 24 and 48h post-confinement. Plasma osmolality, Na(+), Cl(-) and cortisol were taken as indicators of HPIA activation. Plasma AVT was measured proVT mRNA expression in the PM was detected using in situ hybridisation (ISH) with a S35 labelled oligoprobe for homologous flounder proVT. Double IHC showed the presence of GR in AVT synthesising neurones of the PM. Plasma Na(+), Cl(-), osmolality and cortisol (1.0+/-0.9 to 183.6+/-3.1mM; p<0.001) increased significantly 3h post-restraint: recovering to control levels after 48h. Plasma AVT levels did not change. However, a concomitant increase in proVT mRNA expression in the magnocellular (PMm) and gigantocellular (PMg) neurones of the PM was observed (11.1+/-1.8 to 55.2+/-9.1% 24h post-restraint; p<0.001) and levels still remained significantly elevated at 48h (p<0.01). This suggests that PMm and PMg AVT neurones are associated with HPIA activation following acute restraint, including potential cortisol negative feedback. The extended elevation of hypothalamus proAVT mRNA expression following a single acute stressor affords a possible mechanism to moderate sensitivity of the HPIA to subsequent challenges.

  2. Physiological cost of tolerance to toxicants in the European flounder Platichthys flesus, along the French Atlantic Coast.

    PubMed

    Marchand, Justine; Quiniou, Louis; Riso, Ricardo; Thebaut, Marie-Thérèse; Laroche, Jean

    2004-12-20

    Physiological and genetic responses of flounder Platichthys flesus populations were investigated along the French Atlantic Coast in one moderately contaminated estuary (Ster) and three contaminated estuaries (Seine, Loire and Gironde). The focus of this study was to explore the relationship between stress resistance and energetic trade-offs, in order to detect possible differential physiological capacities or performances between individuals carrying particular alleles or genotypes (allozyme data) characterised as "tolerant" or "sensitive". A general reduction of the relative fecundity, the growth rate and the condition factor was highlighted in contaminated fish populations, suggesting that survival in such polluted systems implies energetic costs for fish thus reducing the energy available for particular functions. A lower observed heterozygosity was also detected in contaminated populations with respect to the Ster, suggesting a general decrease in genetic variability in response to chemical stress (with an exception for the Seine estuary). This study confirmed the previously detected relationship between PGM 85, AAT1 95 alleles and reduced DNA damage in contaminated fish [Marchand, J., Tanguy, A., Laroche, J., Quiniou, L., Moraga, D., 2003. Responses of European flounder Platichthys flesus populations to contamination in different estuaries along the Atlantic coast of France. Mar. Ecol. Prog. Ser. 260, 273-284] and furthermore suggested that, reduced fecundity and condition factor associated to the individuals carrying the previous alleles, were also reflecting the cost of resistance to stress in polluted populations. The cost of tolerance to stress as well as the high gene flow from neighbouring populations less exposed to contamination may explain the apparently moderate increase of the suspected "tolerant" alleles in contaminated flounder populations.

  3. Ethoxyresorufin-O-deethylase (EROD) and vitellogenin (VTG) in flounder (Platichthys flesus): system interaction, crosstalk and implications for monitoring.

    PubMed

    Kirby, M F; Smith, A J; Rooke, J; Neall, P; Scott, A P; Katsiadaki, I

    2007-03-10

    The extent to which biological systems interact in fish from multi-contaminant areas needs to be understood for full interpretation of monitoring data. This study investigates the interaction between two biomarkers, ethoxyresorufin-O-deethylase (EROD) activity and plasma vitellogenin (VTG) in the European flounder (Platichthys flesus). Flounder were exposed to several waterborne EROD inducers and estrogenic chemicals on their own and in binary combinations. Each experimental exposure was for 10 days. The estrogenic chemicals suppressed PAH-mediated EROD induction. Ethynylestradiol (EE2) and nonylphenol (NP) had threshold concentrations of EROD inhibition similar to those at which they induced VTG production. Estradiol (E2), however, showed an ability to suppress EROD at a concentration much lower than that at which VTG was induced. This established that, although EE2 is a more potent VTG inducer than E2, it is less potent in its ability to inhibit EROD activity. The PAH, dibenz[a,h]anthracene (DbA), showed no effect on the VTG induction caused by EE2 and E2. A small effect was noted with NP at threshold concentrations for VTG induction. Archived data on flounder hepatic EROD activity collected during estuarine monitoring were reassessed in light of the project findings. It is hypothesised that published EROD monitoring data may be an underestimation of effects if it is assumed that estrogen-mediated MFO suppression is occurring in wild populations. A greater understanding of system interaction and other factors, including genetics, that influence biomarker response to contaminants would be required to interpret biomarker monitoring data.

  4. Diseases of flounder ( Platichthys Flesus L.) in the Dutch Wadden Sea, and their relation to stress factors

    NASA Astrophysics Data System (ADS)

    Dick Vethaak, A.

    In 1988 a survey was conducted on the occurrence of gross pathologies in flounder ( Platichthys flesus L.) in the Dutch Wadden Sea in relation to stress factors, especially near fresh-water drainage sluices. A total of 9608 flounder were collected from 16 sites in June and September. Diseases recorded were: skin ulcers (affecting 7.7% of fish); fin rot (2.8%; only included in the study in September); lymphocystis (3.7%); skeletal deformities (0.3%); liver nematode infections (5.0%); intestinal cysts of the parasite Glugea sp. (0.4%); and liver nodules (pre-neoplastic and neoplastic lesions) (< 0.1%). Prevalences of skin ulcers and fin rot in Wadden Sea flounder are considerably higher than in those captured off the Dutch North Sea coast or in the Elbe estuary in Germany. These high disease levels in the Wadden Sea, however, are largely due to extremely high prevalences of skin ulcers observed near the drainage sluices of Lake IJssel, indicating a localized effect. Fin rot occurs at relatively high prevalences over the whole study area, but the data should be interpreted with some caution, due to diagnostic problems. Associations with possible disease determinants were investigated and causal hypotheses formulated. In general fish seem to develop skin diseases at sites with strong salinity fluctuations. Nutritional deficiencies possibly related to strong salinity fluctuations, high bacterial loads in the environment and obstacles to fish migration through sluices are amongst the most likely factors determining the locally high levels of skin ulcers. Although not established, it is possible that pollution-related factors and contaminant bioavailability are important. The stress imposed by a combination of these factors may adversely affect the immune system, making the fish vulnerable to opportunistic bacterial infection.

  5. An integrated assessment of pollution and biological effects in flounder, mussels and sediment in the southern Baltic Sea coastal area.

    PubMed

    Dabrowska, Henryka; Kopko, Orest; Lehtonen, Kari K; Lang, Thomas; Waszak, Ilona; Balode, Maija; Strode, Evita

    2017-02-01

    Organic and metal contaminants and biological effects were investigated in flounder, mussels, and sediments in the southern Baltic Sea coastal area in order to assess environmental quality status in that area. Four sites were selected, including two within the Gulf of Gdańsk (GoG). In biota and sediment at each site, DDTs dominated over PCBs and PBDEs were the least abundant among organic contaminants. Their concentrations decreased progressively outward from GoG. Among metal contaminants, the levels of Hg, Pb, and Cd were elevated in GoG. Biomarkers in flounder, EROD activity and DNA SB, showed moderate positive correlations with organic and metal contaminants. In flounder, the integrated biomarker index (IBR/n) presented a spatial trend coherent with chemical pollution index (CPI), but there was no clear spatial correspondence between IBR/n and CPI in mussels nor between sediment toxicity index (STI) and sediment CPI. The integrated assessment of contaminant and biological effect data against available assessment criteria indicated that in biota, the contaminant assessment thresholds were most often exceeded by CB-118, heptachlor, PBDE, and Hg (in the GoG sediments by p,p'-DDT, Hg and Cd), while of the biological determinants, the threshold was breeched by AChE activity in mussels in GoG. Applying the ICES/OSPAR traffic-light approach showed that of the 50 parameters assessed at each site, there were 18% of determinants in the red color category in the two GoG sites and 8% of determinants in the two sites outside GoG, which indicated that none of the four investigated sites attained good environmental status (GES).

  6. Genetic diversity in two Japanese flounder populations from China seas inferred using microsatellite markers and COI sequences

    NASA Astrophysics Data System (ADS)

    Xu, Dongdong; Li, Sanlei; Lou, Bao; Zhang, Yurong; Zhan, Wei; Shi, Huilai

    2012-07-01

    Japanese flounder is one of the most important commercial species in China; however, information on the genetic background of natural populations in China seas is scarce. The lack of genetic data has hampered fishery management and aquaculture development programs for this species. In the present study, we have analyzed the genetic diversity in natural populations of Japanese flounder sampled from the Yellow Sea (Qingdao population, QD) and East China Sea (Zhoushan population, ZS) using 10 polymorphic microsatellite loci and cytochrome c oxidase subunit I (COI) sequencing data. A total of 68 different alleles were observed over 10 microsatellite loci. The total number of alleles per locus ranged from 2 to 9, and the number of genotypes per locus ranged from 3 to 45. The observed heterozygosity and expected heterozygosity in QD were 0.733 and 0.779, respectively, and in ZS the heterozygosity values were 0.708 and 0.783, respectively. Significant departures from Hardy-Weinberg equilibrium were observed in 7 of the 10 microsatellite loci in each of the two populations. The COI sequencing analysis revealed 25 polymorphic sites and 15 haplotypes in the two populations. The haplotype diversity and nucleotide diversity in the QD population were 0.746±0.072 8 and 0.003 34±0.001 03 respectively, and in ZS population the genetic diversity values were 0.712±0.047 0 and 0.003 18±0.000 49, respectively. The microsatellite data ( F st =0.048 7, P <0.001) and mitochondrial DNA data ( F st =0.128, P <0.001) both revealed significant genetic differentiation between the two populations. The information on the genetic variation and differentiation in Japanese flounder obtained in this study could be used to set up suitable guidelines for the management and conservation of this species, as well as for managing artificial selection programs. In future studies, more geographically diverse stocks should be used to obtain a deeper understanding of the population structure of Japanese

  7. Long-term assessment of settlement and growth of juvenile winter flounder ( Pseudopleuronectes americanus) in New Jersey estuaries

    NASA Astrophysics Data System (ADS)

    Sogard, Susan M.; Able, Kenneth W.; Hagan, Stacy M.

    2001-06-01

    We examined patterns of metamorphosis, settlement, and growth for young-of-the-year winter flounder over a ten year period (1990-1999) in four estuaries spanning the coast of New Jersey, USA, with the objective to determine the spatial and temporal coherence in these processes. We hypothesised that these processes could be influenced by large-scale climatic factors such as temperature and small-scale, local factors such as predator and prey abundances and differences associated with the localised population structure of winter flounder. Newly settled juveniles were collected in late May/early June each year. Increment counts on sagittal otoliths were used to determine the date of metamorphosis, and increment widths were used to estimate growth rates at two times, just after settlement and just prior to capture. A high level of consistency in spatial patterns among four individual estuaries was evident, and was largely driven by the northernmost site, Sandy Hook, which had higher fish densities and later metamorphosis than the three other sites, and faster growth rates than the two mid-coast sites (Barnegat Bay and Great Bay). In contrast to spatial patterns, consistent temporal patterns were evident only in the timing of metamorphosis, which was delayed in colder years at all sites. Weekly plankton sampling over the same ten year period at one site (Great Bay) yielded winter flounder larvae during a relatively narrow period in spring, with a later peak of abundance in colder years, in agreement with back-calculated dates of metamorphosis for settled juveniles. These patterns suggest that the timing of settlement is driven by large-scale climatic factors that influence the timing of spawning and/or larval development. Interannual variability in densities and growth rates, however, appeared to be independent at each site, indicating control by local environmental factors or genetic differences among local populations. The spatial consistency of growth rates suggests

  8. The use of innate immune responses as biomarkers in a programme of integrated biological effects monitoring on flounder (Platichthys flesus) from the southern North Sea

    NASA Astrophysics Data System (ADS)

    Skouras, Andreas; Broeg, Katja; Dizer, Halim; von Westernhagen, Hein; Hansen, Peter-Diedrich; Steinhagen, Dieter

    2003-10-01

    Immunological biomarkers that reflect the effects of exposure to environmental contaminants in coastal marine habitats were sought in European flounder (Platichthys flesus) from five locations in the German Bight with different anthropogenic impacts. During a 2-year period of sampling, innate immune responses were monitored from a total of 331 individual flounder of a body length of 18 to 25 cm. From the fish, plasma lysozyme, phagocytosis and respiratory burst activity of head kidney leucocytes were analysed and implemented as part of an integrated biological effects monitoring programme. As the measurements of the parameters applied here varied within wide ranges at some locations, spatial differences could not always be established, but some general trends could be drawn: plasma lysozyme activity was decreased in flounder contaminated with DDT adducts and some PCBs, while cellular functions such as phagocytosis and respiratory burst were stimulated by some chlorinated hydrocarbons. Correlation analysis also revealed connections not only between the parameters applied here and some contaminants but also with some biochemical parameters used as biomarkers in pollution monitoring: in flounder with decreased integrity of hepatocyte lysosomal membranes, immune functions also were impaired, and plasma lysozyme as well as phagocytosis activity of head kidney cells were impaired when the activity of cytochrome P450 1A was induced. The data presented here indicate that innate immune responses may be useful parameters to monitor cellular functions in a battery of biomarkers of different levels of biological organisation.

  9. Vitellogenin as biomarker for estrogenicity in flounder Platichthys flesus in the field and exposed to 17α-ethinylestradiol via food and water in the laboratory.

    PubMed

    Madsen, Louise Leonharder; Korsgaard, Bodil; Pedersen, Knud Ladegaard; Bjerregaard, Lisette Bachmann; Aagaard, Thomas; Bjerregaard, Poul

    2013-12-01

    The ability of 17α-ethinylestradiol (EE2) to elevate vitellogenin levels were investigated in male flounder Platichthys flesus and vitellogenin concentrations in flounders from the Danish coastal environment were determined. Male flounders were exposed to 17α-ethinylestradiol (EE2) via food or water. Average vitellogenin concentrations in the control fish ranged between 25 and 100 ng mL(-)(1). Exposure to 5.1, 8.1 and 16.8 ng EE2 L(-)(1) in water and 500 and 5000 ng EE2 kg(-)(1) body weight (bw) every second day in the food increased the plasma vitellogenin concentration in a concentration and time dependent manner, whereas exposure to 2.7 ng EE2 L(-)(1) in water for 21 d and 5 and 50 ng EE2 kg(-)(1) bw for 12 days in the food did not. EE2 could be detected in liver and testes (but not in muscle) after exposure to 8.1 and 16.8 ng EE2 L(-)(1) in the water and 5000 ng EE2 kg(-)(1) bw in the food; the highest concentration was 6 ng g(-)(1) wet weight in liver. The majority of the male flounders collected from nine coastal Danish sites from 1999 to 2004 had vitellogenin concentrations below 100 ng mL(-)(1), and only at two sites moderate estrogenic inputs were indicated.

  10. Molecular characterisation and expression of parathyroid hormone-related protein in the caudal neurosecretory system of the euryhaline flounder, Platichthys flesus.

    PubMed

    Lu, Weiqun; Jin, Yingying; Xu, Jinling; Greenwood, Michael P; Balment, Richard J

    2017-02-27

    Parathyroid hormone-related protein (PTHrP) is a hypercalcemic factor in fish, but the source of circulating PTHrP remains unclear. In this study investigation of the caudal neurosecretory system (CNSS), considered one of major sources of PTHrP in fish, provided valuable insights into this regulatory system. We report pthrpa and pthrpb gene cloning, characterization, expression, and responses to low salinity and hypocalcemia challenge in flounder. The pthrpa and pthrpb precursors, isolated from a European flounder CNSS library, consist of 166 and 192 amino acid residues, respectively, with an overall homology of approximately 59.2%. Both precursors contain a signal peptide and a mature peptide with cleavage and amidation sites. The flounder PTHrPA and PTHrPB peptides share only 41% sequence identity with human PTHrPA. Quantitative PCR analysis demonstrated that the bone and bladder, are respectively major sites of pthrpa and pthrpb expression in flounder. Urophysectomy confirmed the CNSS as a likely contributor to circulating PTHrP peptides. There were no significant differences in CNSS pthrpa and pthrpb mRNA expression or plasma PTHrP levels between seawater (SW) and freshwater (FW)-adapted fish, though plasma total calcium concentrations were higher in FW animals. The intraperitonial administration of EGTA rapidly induced hypocalcemia and concomitant elevation in plasma PTHrP accompanied by increases in both pthrpa and pthrpb expression in the CNSS. Together, these findings support an evolutionary conserved role for PTHrP in the endocrine regulation of calcium.

  11. ASSESSING HABITAT QUALITY OF MOUNT HOPE BAY AND NARRAGANSETT BAY USING GROWTH, RNA:DNA, AND FEDDING HABITS OF CAGED JUVENILE WINTER FLOUNDER

    EPA Science Inventory

    Somatic growth rates, RNA:DNA, and feeding habits of juvenile Pseudopleuronectes americanus (Winter Flounder) were used to asses small-scale spatio-temporal variations in the habitat quality of Mount Hope Bay and Narragan-sett Bay, RI. Three successive caging experiments (14–16 d...

  12. Diet, consumption, and growth of juvenile fringed flounder ( Etropus crossotus); a test of the 'maximum growth/optimum food hypothesis' in a subtropical nursery area

    NASA Astrophysics Data System (ADS)

    Reichert, Marcel J. M.

    2003-11-01

    Recent somatic growth of juvenile fringed flounder ( Etropus crossotus) collected in North Inlet (South Carolina, USA) was determined based on the width of the 24 most recently deposited daily increments in sagittal otoliths. Growth rates were estimated using previously published data on the experimentally validated relationship between the daily increment width and the somatic growth. A comparison of the realised growth with experimental data indicated that growth rates in the field were near optimum values determined under ad libitum food conditions. Gut contents analysis of field collected fringed flounder indicated that food consisted predominantly of zooplankton and motile epibenthic prey with calanoid copepods, in particular Pseudodiaptomus coronatus, as the most important food items. There was no clear ontogenetic shift in prey with increasing fish size. Copepods and their eggs remained a significant prey item in even the largest fish examined (>9 cm SL), while larger prey items like polychaete worms, cumaceans, bivalves, and mysids were found in the stomachs of smaller fish. The prey organisms were abundantly available during the period of highest settlement (May through September). Growth rates, biomass, consumption estimates, and prey availability in North Inlet indicated that growth of juvenile fringed flounder is not limited by food, but predominantly determined by water temperature. During the summer months temperature and food supply in North Inlet are near optimal for juvenile fringed flounder. This allows this short-lived species to grow rapidly to attain a mature size and migrate to near-shore waters to reproduce within one growing season.

  13. Bioavailability of selenium from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine, and sodium selenite assessed in selenium-deficient rats.

    PubMed

    Wen, H Y; Davis, R L; Shi, B; Chen, J J; Chen, L; Boylan, M; Spallholz, J E

    1997-01-01

    The bioavailability of selenium (Se) from veal, chicken, beef, pork, lamb, flounder, tuna, selenomethionine (SeMet), and sodium selenite was assessed in Se-deficient Fischer-344 rats. Se as veal, chicken, beef, pork, lamb, flounder, tuna, SeMet, and sodium selenite was added to torula yeast (TY) basal diets to comprise Se-inadequate (0.05 mg Se/kg) diets. Se as sodium selenite was added to a TY basal diet to comprise a Se-adequate (0.10 mg Se/kg), Se-control diet. The experimental diets were fed to weanling Fischer-344 rats that had been subjected to dietary Se depletion for 6 wk. After 9 wk of the dietary Se repletion, relative activity of liver glutathione peroxidase (GSHPx) from the different dietary groups compared with control rats (100%) was: flounder 106%, tuna 101%, pork 86%, sodium selenite 81%, SeMet 80%, beef 80%, chicken 77%, veal 77%, and lamb 58%. Se from flounder was the most efficient at restoring Se concentrations in the liver and skeletal muscle. Se from sodium selenite, SeMet, beef, veal, chicken, pork, lamb, and tuna was not dietarily sufficient to restore liver and muscle Se after 9 wk of recovery following a 6-wk period of Se depletion.

  14. Histopathological, histomorphometrical, and immunohistochemical biomarkers in flounder (Platichthys flesus) from the southern Baltic Sea.

    PubMed

    Dabrowska, Henryka; Ostaszewska, Teresa; Kamaszewski, Maciej; Antoniak, Agnieszka; Napora-Rutkowski, Lukasz; Kopko, Orest; Lang, Thomas; Fricke, Nicolai F; Lehtonen, Kari K

    2012-04-01

    Flounder (Platichthys flesus), collected in late fall of 2009 from four coastal sites in the southern Baltic Sea including the Gulf of Gdańsk (GoG), were investigated for a suite of biomarkers of contaminant effects. The biomarkers included liver histopathologies, which were diagnosed and assessed using commonly applied lesion categories, the size and density of melano-macrophage aggregates (MMAs), expression of proliferating cell nuclear antigen (PCNA) and of cytochrome P450 1A (CYP1A) in liver as well as the size and density of MMAs and density of Perls'-positive cells in the spleen. The prevalence of liver lesions differed among the sites. Most frequently occurring were non-specific and early toxicopathic non-neoplastic lesions. Mean MMA size was in the range of 264-519 μm(2) and 717-2137 μm(2) in liver and spleen, respectively, and density was in the range of 6-13 and 15-26 MMAmm(-2), respectively. Mean density of PCNA-positive hepatocytes was in the range of 300-1281 cellsmm(-2). These histomorphometrical biomarkers correlated positively with the muscle Hg, Σ(7)PCB, and ΣDDT residues and negatively with the indices of general liver condition. They showed significant differences between the sites, which were in line with the spatial prevalence of liver lesions and CYP1A induction. Overall, the biomarker responses were more pronounced in the GoG sites in comparison to those outside the Gulf, which confirms some earlier results and broadens the knowledge of contaminant effects in the Polish coastal zone of the Baltic Sea.

  15. The gender-specific risk to liver toxicity and cancer of flounder (Platichthys flesus (L.)) at the German Wadden Sea coast.

    PubMed

    Koehler, Angela

    2004-12-20

    Flatfish living in coastal areas are chronically exposed to a wide range of toxic and (pro)carcinogenic compounds derived from agriculture and industry. Flounder (Platichthys flesus (L.)) is the main target species for monitoring health effects of contamination in North Sea and Baltic Sea since the species is abundant, benthic, and inhabits shallow waters such as the Wadden Seas and estuaries along salinity gradients into fresh water. Chemical analysis in the same livers as investigated for histopathology in the present study showed positive correlation between accumulation of certain organochlorines in liver and the extend of liver injury. Toxipathic liver changes including neoplasms in female and male flounder were analysed by macroscopic and light microscopic diagnosis during a five-year survey on the basis of internationally accepted criteria agreed upon during the European BEQUALM intercalibration of liver histopathology of flatfish. Hepatocellular carcinogenesis of wild flounder principally showed sequential changes similar to experimental chemical carcinogenesis in other fish species and mammals. These ranged from early foci of altered hepatocytes (vacuolated/clear/eosinophilic, basophilic cells) and the development of adenomas. With progression to hepatocellular carcinomas, livers of wild flounder entered a multistage phase of carcinogenesis comprising of early foci, hepatocellular adenomas and carcinomas, as observed in human liver cancers. Female flounder had three-fold higher frequencies of macroscopically visible neoplasms than males of the same age classes. Histopathological diagnosis showed that hepatocellular alterations in male flounder never developed further than stages of basophilic foci and adenomas, and never into malignancies. In females, tumors of hepatocellular origin clearly dominated, occurred alone and together with cancers of bile duct epithelial cells and endothelial cells (cholangio-carcinomas, angiosarcomas). Because mutations of

  16. A combined measurement of metal bioaccumulation and condition indices in juvenile European flounder, Platichthys flesus, from European estuaries.

    PubMed

    Kerambrun, E; Henry, F; Cornille, V; Courcot, L; Amara, R

    2013-04-01

    Condition indices and metal bioaccumulation of early life stages of juvenile flounder (5-10 cm) were determined in three anthropogenic estuaries (the Scheldt, Seine and Loire) and compared to a reference site (the Canche). Significant correlations were found between metal concentrations in sediment and (i) fish liver for Cd, Cu, Ni, Pb, V and Zn and (ii) fish gills for Cd and Mn. Metal accumulation in juvenile flounder from the three anthropogenic estuaries coincided with significantly lower Fulton's K indices (from 0.99 ± 0.03 to 1.06 ± 0.01 mg mm(-3)) compared to those from the Canche estuary (from 1.02 ± 0.01 to 1.13 ± 0.01 mg mm(-3)). This discrepancy in fish condition index increased with fish size and therefore, strongly depends on the time juvenile spend in estuary. Muscle lipid contents and Triacylglycerol to Sterol ratios were significantly lower in fish collected in the Scheldt (lipid content: 21.3 ± 3.6%), Seine (17.9 ± 19.8%) and Loire (19.5 ± 2.4%) estuaries compared to those originating from the Canche (38.3 ± 4.6%). This study highlights that combined measures of both fish metal contents and condition indices gives a relevant assessment of juvenile fish health growing in anthropogenic estuaries.

  17. Evolutionary mechanisms shaping the genetic population structure of marine fishes; lessons from the European flounder (Platichthys flesus L.).

    PubMed

    Hemmer-Hansen, Jakob; Nielsen, Einar Eg; Grønkjaer, Peter; Loeschcke, Volker

    2007-08-01

    A number of evolutionary mechanisms have been suggested for generating low but significant genetic structuring among marine fish populations. We used nine microsatellite loci and recently developed methods in landscape genetics and coalescence-based estimation of historical gene flow and effective population sizes to assess temporal and spatial dynamics of the population structure in European flounder (Platichthys flesus L.). We collected 1062 flounders from 13 localities in the northeast Atlantic and Baltic Seas and found temporally stable and highly significant genetic differentiation among samples covering a large part of the species' range (global F(ST) = 0.024, P < 0.0001). In addition to historical processes, a number of contemporary acting evolutionary mechanisms were associated with genetic structuring. Physical forces, such as oceanographic and bathymetric barriers, were most likely related with the extreme isolation of the island population at the Faroe Islands. A sharp genetic break was associated with a change in life history from pelagic to benthic spawners in the Baltic Sea. Partial Mantel tests showed that geographical distance per se was not related with genetic structuring among Atlantic and western Baltic Sea samples. Alternative factors, such as dispersal potential and/or environmental gradients, could be important for generating genetic divergence in this region. The results show that the magnitude and scale of structuring generated by a specific mechanism depend critically on its interplay with other evolutionary mechanisms, highlighting the importance of investigating species with wide geographical and ecological distributions to increase our understanding of evolution in the marine environment.

  18. Early contamination of European flounder (Platichthys flesus) by PCDD/Fs and dioxin-like PCBs in European waters.

    PubMed

    Nunes, Margarida; Martinho, Filipe; Vernisseau, Anaïs; Marchand, Philippe; Le Bizec, Bruno; van der Veer, Henk W; Cabral, Henrique N; Ramos, Fernando; Pardal, Miguel A

    2014-08-15

    Contamination levels and profiles of 7 polychlorinated-p-dioxins, 10 polychlorinated furans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were investigated in juvenile European flounder (Platichthys flesus) captured in different nursery areas in the northeastern Atlantic coast across its geographical distribution range. The toxic equivalent concentrations (WHO-TEQfish) were also determined in order to evaluate which P. flesus population was more exposed to dioxin-like toxicity. Juveniles caught in the Sørfjord (Norway) showed the lowest WHO-TEQfish concentration (0.052 pg WHO-TEQfish g(-1)wet weight) whereas the highest value was observed in fish from the Wadden Sea (The Netherlands; 0.291 pg WHO-TEQfish g(-1)ww), mainly due to the greater contribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin, the most toxic congener. Nonetheless, when comparing the results with existent tissue residue-based toxicity benchmarks, no adverse effects resulting from PCDD/Fs and dl-PCBs are expected to occur in flounder from the studied systems.

  19. On the population dynamics of dab, sole and flounder within bridgwater bay in the lower severn estuary, England

    NASA Astrophysics Data System (ADS)

    Henderson, P. A.; Holmes, R. H. A.

    A ten year study of the population dynamics of the flatfish dab Limanda limanda, sole Solea solea and flounder Platichthys flesus was undertaken within Bridgwater bay in the Bristol Channel, England. Fish abundance was estimated from the rate of capture on power station intake filter screens at Hinkley Point Nuclear Power Station. The Bay was used as an 0-group nursery by all three species while flounder were alone in regularly using the area as adults. Using the coefficient of variation (CV) in annual catch as a measure of population stability these three flatfish were found to have some of the most stable populations within a fish community of 21 common species. When these species were classified according to their use of space as benthic, proximo-benthic or pelagic it was found that the benthic fish had the lowest CV values. It is argued that this stability is linked to their use of space. A notable feature was the differing seasonal occupancy of the Bay by the benthic fish which would act to reduce potential inter-specific competition. This suggests that spatial competition could only be intra-specific or against invertebrates. A search was made for biotic or physical factors correlated with year class abundance in the flatfish. The only significant correlation found was for sole, the abundance of which increased with increasing water temperature.

  20. Functional analysis of xenobiotic response elements (XREs) in CYP 1A of the European Flounder (Platichthys flesus).

    PubMed

    Lewis, Nicholas; Williams, Tim D; Chipman, Kevin

    2004-01-01

    The induction of hepatic cytochrome P450 1A (CYP 1A) is an important step in the response to contaminants such as polycyclic aromatic hydrocarbons (PAHs), and has been used as a biomarker of exposure in fish. Several consensus response elements have been identified, including eight potential xenobiotic response elements (XREs) in the promoter region of the European flounder cytochrome P450 1A gene. However not all of these sequences are necessarily active. To help elucidate the molecular regulation of this important gene, site directed mutagenesis and dual-luciferase reporter gene assays were employed to characterize the consensus transcription factor binding sites of the CYP 1A 5' flanking region. Mutation of response elements situated -1103, -859, -709 and -172 bases upstream of the transcription start site reduced the induction to 2.75, 1.51, 3.25 and 3.05 fold, respectively, compared with the full-length promoter (4.0-fold induction) on exposure to the PAH 3-methylcholanthrene (3MC) (1.0 microM). These results indicate that four out of eight different XREs are functional in the control of CYP 1A in the flounder. The activity of these response elements adds to the evidence for considerable diversity in vertebrate CYP 1A regulation.

  1. Oxidative stress biomarkers in two resident species, mullet (Mugil cephalus) and flounder (Platichthys flesus), from a polluted site in River Douro Estuary, Portugal.

    PubMed

    Ferreira, M; Moradas-Ferreira, P; Reis-Henriques, M A

    2005-01-18

    Exposure of marine animals to certain pollutants can enhance reactive oxygen species (ROS) production with subsequent damage to macromolecules and alterations in oxidant defences levels. Aimed at correlating the tissue concentration of certain contaminants (PCBs, DDT) with antioxidant defence levels and oxidative damages, two fish species with different life strategies (mullet, Mugil cephalus, and flounder, Platichthys flesus) were collected in the Douro Estuary (NW Portugal). After capture, the fish were left to depurate for 1 month in clean seawater. The levels of the two antioxidant enzyme activities revealed that they are species-dependent with mullet's livers showing higher superoxide dismutase (SOD) (13.2+/-0.5 U/mg protein) and catalase (CAT) (15.5+/-1.0 mmol/min/mg protein) activities than flounder (SOD: 7.9+/-0.9 U/mg protein; CAT: 11.1+/-0.8 mmol/min/mg protein). After 1 month in captivity the antioxidant enzymes activities in liver decreased in mullets, while for flounders the responses were not consistent because during the experimental period flounders did not ate and responses of antioxidant enzymes and oxidative damages were dependent on the fasting condition. The liver oxidative damages were evaluated by estimating oxidised lipids and proteins. Both species showed similar levels for these two parameters. The hepatic lipid peroxidation in flounder increased after 1 month in captivity, while in mullet an increase was observed only in summer and autumn. The oxidised protein content increased for both species after the depuration period. This study reveals differences between species under oxidative stress when exposed to pollutants. In a clean environment, the mullet's primary antioxidant defences decreased indicating that the animals living in Douro estuary were facing an oxidative stress. The data indicate that, namely in mullet, the presence of pollutants induce oxidative stress responses.

  2. Intraspecific variation in expression of candidate genes for osmoregulation, heme biosynthesis and stress resistance suggests local adaptation in European flounder (Platichthys flesus).

    PubMed

    Larsen, P F; Nielsen, E E; Williams, T D; Loeschcke, V

    2008-09-01

    Despite the recent discovery of significant genetic structuring in a large number of marine organisms, the evolutionary significance of these often minute genetic differences are still poorly understood. To elucidate the adaptive relevance of low genetic differentiation among marine fish populations, we studied expression differences of osmoregulatory and stress genes in genetically weakly differentiated populations of the European flounder (Platichthys flesus), distributed across a natural salinity gradient. Flounders were maintained in a long-term reciprocal transplantation experiment mimicking natural salinities in the North Sea and the Baltic Sea. Applying real-time quantitative PCR and microarray analysis we studied expression of four candidate genes (hsp70, angiotensinogen, Na/K-ATPase-alpha and 5-aminolevulinic acid synthase (ALAS)) in gill, kidney and liver tissues. Genes involved in osmoregulative processes (Na/K-ATPases-alpha and angiotensinogen) showed highly plastic but similar expression in the two populations dependent on environmental salinity. However, we observed a unique sixfold up-regulation of hsp70 in kidney tissue of flounder from the North Sea following long-term acclimation to Baltic salinities. Similarly, significant differences between North Sea and Baltic flounders in expression of ALAS in response to different salinities were found in gill and liver tissue. These findings strongly suggest that gene expression in flounders is shaped by adaptation to local environmental conditions. This identification of adaptive differences in high gene flow marine organisms adds a new dimension to our current understanding of evolutionary processes in the sea and is of paramount importance for identification, protection and sustainable management of marine biodiversity.

  3. Reduction in organic contaminant exposure and resultant hepatic hydropic vacuolation in winter flounder (Pseudopleuronectes americanus) following improved effluent quality and relocation of the Boston sewage outfall into Massachusetts Bay, USA: 1987-2003.

    PubMed

    Moore, Michael; Lefkovitz, Lisa; Hall, Maury; Hillman, Robert; Mitchell, David; Burnett, Jay

    2005-02-01

    Effluent upgrades for metropolitan Boston have included toxicant reduction, primary and secondary treatment and outfall extension. Between 1992 and 2003 winter flounder at five stations were surveyed annually for liver and muscle burden and chronic hepatic sub-lethal impacts of polynuclear and halogenated aromatic hydrocarbons, and metals. Trends in flounder availability and fin condition were also examined. In 1988 12% of the adult winter flounder in Boston Harbor exhibited hepatic neoplasms and up to 80% had hepatic hydropic vacuolation (HV). Tumor prevalence fell to 0-2% and HV to <50% by 1996. Since then tumors have been absent, while a steady prevalence of HV has persisted, consistent with lower hydrocarbon loading and tissue levels. Contaminants and HV also fell with distance from the Boston outfall. After the outfall extension was activated in 2000, there has been no significant change in flounder liver health at the new outfall site.

  4. Susceptibility of cultured juveniles of several marine fish to the sevenband grouper nervous necrosis virus.

    PubMed

    Tanaka, S; Kuriyama, I; Nakai, T; Miyazaki, T

    2003-02-01

    Piscine nodaviruses (betanodaviruses) have been tentatively divided into four genotypes (SJNNV, RGNNV, TPNNV and BFNNV) and it is suggested that host specificity is different among these genotypes. In the present study, a betanodavirus [sevenband grouper nervous necrosis virus (SGNNV)] belonging to the redspotted grouper nervous necrosis virus (RGNNV) genotype, to which most betanodaviruses from warm water fish are identified, was evaluated for its pathogenicity to hatchery-reared juveniles of several marine fish species. When challenged with the virus by a bath method (10(5.1) TCID50 mL(-1)), sevenband grouper, Epinephelus septemfasciatus, Japanese flounder, Paralichthys olivaceus, and tiger puffer, Takifugu rubripes, displayed behavioural abnormalities and mortalities with distinct histopathological signs of viral nervous necrosis and heavily immunostained cells were observed in the central nervous tissues and retina. Bath-challenged rock fish, Sebastiscus marmoratus, and a hybrid of sevenband grouper and kelp grouper, E. moara, did not display any behavioural abnormality or mortality during the experimental period, although many fish showed slight signs of viral infection in nerve cells. Kelp grouper and red sea bream, Pagrus major, showed no behavioural abnormality, mortality or immunohistopathological changes after the virus challenge. These results are, in part, consistent with the natural host range of RGNNV, indicating the complexity in the host specificity of betanodaviruses.

  5. Development of real-time PCR for detection and quantitation of Streptococcus parauberis.

    PubMed

    Nguyen, T L; Lim, Y J; Kim, D-H; Austin, B

    2016-01-01

    Streptococcus parauberis is an increasing threat to aquaculture of olive flounder, Paralichthys olivaceus Temminck & Schlegel, in South Korea. We developed a real-time polymerase chain reaction (PCR) method using the TaqMan probe assay to detect and quantify S. parauberis by targeting the gyrB gene sequences, which are effective for molecular analysis of the genus Streptococcus. Our real-time PCR assay is capable of detecting 10 fg of genomic DNA per reaction. The intra- and interassay coefficient of variation (CV) values ranged from 0.42-1.95%, demonstrating that the assay has good reproducibility. There was not any cross-reactivity to Streptococcus iniae or to other streptococcal/lactococcal fish pathogens, such as S. agalactiae and Lactococcus garvieae, indicating that the assay is highly specific to S. parauberis. The results of the real-time PCR assay corresponded well to those of conventional culture assays for S. parauberis from inoculated tissue homogenates (r = 0.957; P < 0.05). Hence, this sensitive and specific real-time PCR is a valuable tool for diagnostic quantitation of S. parauberis in clinical samples.

  6. Hirame rhabdovirus (HIRRV) as the cause of a natural disease outbreak in cultured black seabream (Acanthopagrus schlegeli) in Korea.

    PubMed

    Kim, Wi-Sik; Oh, Myung-Joo

    2015-12-01

    In 2015, a high mortality rate of about 40% was observed in black seabream (Acanthopagrus schlegeli) on a farm on the southern coast of Korea. Most of the diseased fish showed a hemorrhage of the mouth, pale liver, petechial hemorrhaging in the internal fat, and an enlarged spleen. Other than Alella sp., no parasites or bacteria were isolated from the diseased fish, and all of the tissue filtrates produced cytopathic effects (CPEs) in FHM and CHSE-214 cells. A polymerase chain reaction analysis revealed that the cell culture supernatants with CPE expressed specific 730-bp fragments for the hirame rhabdovirus (HIRRV) phosphoprotein gene. The nucleotide sequences showed a minimum of 95.8% identity to five other known isolates of HIRRV, including CA-9703 and 8401-H from olive flounder (Paralichthys olivaceus) in Korea and Japan. An experimental challenge was conducted in which the virus was delivered by injection, and the cumulative mortalities of black seabream challenged with this new HIRRV isolate at 10(4.8) TCID50/fish and 10(3.8) TCID50/fish were 100% and 20%, respectively. This fulfilled Koch's postulates and confirmed that HIRRV was the cause of disease and mortality for both the natural and experimental infection of black seabream.

  7. Fight-flight or freeze-hide? Personality and metabolic phenotype mediate physiological defence responses in flatfish.

    PubMed

    Rupia, Emmanuel J; Binning, Sandra A; Roche, Dominique G; Lu, Weiqun

    2016-07-01

    Survival depends on appropriate behavioural and physiological responses to danger. In addition to active 'fight-flight' defence responses, a passive 'freeze-hide' response is adaptive in some contexts. However, the physiological mechanisms determining which individuals choose a given defence response remain poorly understood. We examined the relationships among personality, metabolic performance and physiological stress responses across an environmental gradient in the olive flounder, Paralichthys olivaceus. We employed four behavioural assays to document the existence of two distinct behavioural types ('bold' and 'shy') in this species. We found consistent metabolic differences between individuals of a given behavioural type across an environmental gradient: shy individuals had overall lower aerobic scope, maximum metabolic rate and standard metabolic rate than bold individuals in both high (25 ppt) and low (3 ppt) salinity. These behavioural and metabolic differences translated into divergent physiological responses during acute stress: shy individuals adopted a passive 'freeze-hide' response by reducing their oxygen consumption rates (akin to shallow breathing) whereas bold individuals adopted an active 'fight-flight' response by increasing their rates of respiration. These distinct defence strategies were repeatable within individuals between salinity treatments. Although it has been suggested theoretically, this is the first empirical evidence that the metabolic response to stressful situations differs between bold and shy individuals. Our results emphasize the importance of incorporating physiological measures to understand the mechanisms driving persistent inter-individual differences in animals.

  8. First report of Kudoa species in the somatic muscle of the Japanese parrotfish Calotomus japonicus (Scaridae) and a description of Kudoa igami, n. sp. (Myxozoa: Multivalvulida).

    PubMed

    Shirakashi, Sho; Yamane, Koji; Ishitani, Hiroe; Yanagida, Tetsuya; Yokoyama, Hiroshi

    2014-07-01

    Three species of the Kudoid parasite (Myxozoa: Multivalvulida) were observed in the somatic muscle of Japanese parrotfish Calotomus japonicus caught off the coast of western Japan. All three species formed pseudocysts in myofibers and caused subclinical infections. The three Kudoa species were distinguished by spore morphology, as well as their 18S and 28S rDNA sequences. We identified a previously undescribed taxa Kudoa igami n. sp. with spores that were stellate with rounded peripheral edges and five to six polar capsules (prevalence 29.3%). Kudoa igami n. sp. were morphologically most similar to Kudoa neothunni but were distinguishable by a more rounded shape in the apical view. Molecular analyses demonstrated that the K. igami n. sp. is closely related to Kudoa thalassomi; however, the similarity in the 28S rDNA sequence was <96% and the spore morphology was different. We found Kudoa thalassomi in one sample (prevalence 2.4%), which is a new host and geographical record for this species. Kudoa lateolabracis, which causes postmortem myoliquefaction in Chinese sea bass Lateolabrax sp. and olive flounder Paralichthys olivaceus was found in Japanese parrotfish (prevalence 41.5%) for the first time, but did not cause myoliquefaction. We also expanded the host record for the brain-infecting Kudoa yasunagai (prevalence 94.1%). In addition, an unidentified microsporidia was observed in the somatic muscle (prevalence 23.3%).

  9. Full-genome sequence of a novel myovirus, GF-2, infecting Edwardsiella tarda: comparison with other Edwardsiella myoviral genomes.

    PubMed

    Yasuike, Motoshige; Nishiki, Issei; Iwasaki, Yuki; Nakamura, Yoji; Fujiwara, Atushi; Sugaya, Emi; Kawato, Yasuhiko; Nagai, Satoshi; Kobayashi, Takanori; Ototake, Mitsuru; Nakai, Toshihiro

    2015-08-01

    Edwardsiellosis, which is caused by Edwardsiella tarda, a Gram-negative bacterium, is one of the most serious infectious diseases in both marine and freshwater fish farms worldwide. Previously, we reported the complete genome sequences of three E. tarda-lytic bacteriophages (two podoviruses and a myovirus), which were isolated from fish tissues and fish-rearing seawater. Further genomic information regarding E. tarda phages is important for understanding phage-host interactions as well as for applications of the phages for the control of disease. Here, we report the complete genome sequence of a novel E. tarda phage (GF-2) of myovirus morphology (family Myoviridae), isolated from tissue homogenates of a cultured Japanese flounder (Paralichthys olivaceus) that succumbed to edwardsiellosis in Japan. The size of the entire genome was 43,129 bp, with a GC content of 51.3 % and containing 82 open reading frames (ORFs). The GF-2 genome possesses lysogeny-related genes that have not been found in the reported Edwardsiella phage genomes. Comparative genomics of Edwardsiella myophages suggest that the C-terminal domains of the tail fiber proteins have relevance to their host specificity. Thus, GF-2 genome information provides a novel resource for our understanding of the molecular mechanisms involved in their host specificity and for detection of E. tarda in aquaculture environments.

  10. Severe scuticociliate (Philasterides dicentrarchi) infection in a population of sea dragons (Phycodurus eques and Phyllopteryx taeniolatus).

    PubMed

    Rossteuscher, S; Wenker, C; Jermann, T; Wahli, T; Oldenberg, E; Schmidt-Posthaus, H

    2008-07-01

    Scuticociliatosis is a disease of fish induced by ciliated parasites of the genus Scuticociliatida. It has been described in sea horses (Hippocampus sp.), flounders (Paralichthys olivaceus), and turbots (Scophthalmus maximus). Here we present a case study of a population of sea dragons chronically infected with scuticociliates identified as Philasterides dicentrarchi by histopathology and PCR. Beginning in 2004, over a period of 19 months, 10 sea dragons (Phycodurus eques and Phyllopteryx taeniolatus) were found dead in an aquarium of the Zoological Garden Basle, Switzerland. Clinically, the animals showed only faint symptoms of disease over a short period of time. At necropsy, macroscopic lesions were confined to the skin with multiple, often hemorrhagic, ulcerations. Histologically, epidermal ulcers were associated with necrosis and inflammation of the underlying dermis and musculature. Numerous ciliates, with a morphology consistent with scuticociliates, were present in these lesions. In several animals these ciliates had invaded blood vessels and were detected in gills and internal organs including kidney, thyroid gland, and central nervous system (CNS). In these organs, mild degenerative lesions and inflammatory reactions were evident. The ciliates were identified as Philasterides dicentrarchi based on small-subunit ribosomal RNA (SSUrRNA) gene sequences obtained by polymerase chain reaction (PCR) on DNA extracted from paraffin-embedded tissue sections. Our report shows that scuticociliate infections of sea dragons can develop into a systemic infection and that both species of sea dragons can be affected.

  11. Responses of juvenile European flounder (Platichthys flesus) to multistress in the Vilaine estuary, during a 6-month survey.

    PubMed

    Evrard, Estérine; Devaux, Alain; Bony, Sylvie; Cachot, Jérôme; Charrier, Grégory; Quiniou, Louis; Laroche, Jean

    2013-02-01

    Physiological and genetic responses of age 0+ Platichthys flesus were investigated in the eutrophicated and moderately contaminated Vilaine estuary, during a 6-month survey. The main objective of this study was to explore the biological responses of fishes during their juvenile period in an estuarine system in order to detect a possible selective pressure induced by the environmental stress. Our results showed a general convergence in physiological responses along the survey: an increase in genotoxicity was associated with an increase in mRNA expression of ATPase and betaine homocysteine methyltransferase. These results could suggest an increase of cellular damage, energetic request, and detoxification rate related to the growing exposure time to stress. Considering the aging of the cohort, the genetic characteristics of the Vilaine flounder cohort came closer to the one observed in a highly stressed system, the Seine estuary, suggesting a potential selective pressure mainly induced by the chemical stress.

  12. Comparison of selected biomarkers in flounder (Platichthys flesus L.) from the Douro (Portugal) and Vistula (Poland) River estuaries.

    PubMed

    Kopecka-Pilarczyk, Justyna

    2013-08-15

    Sixty female flounder (Platichthys flesus) were collected in Autumn 2011, 15 from each of the following sampling sites: at the mouths of the Douro and Vistula Rivers, and at nearby open sea locations. The aim of the study was to assess several biomarkers in the two geographically distant regions. Hepatic EROD, GST, SOD, GPx, POx, LP; muscular AChE, BChE, LP; and branchial Na(+)/K(+)-ATPase were analysed. Moreover, BTI, PY, and three gross morphometric indices were calculated. The results were analysed with t-test, ANOVA, and PCA. Many differences were found between the open sea sites and the river mouths, mainly in Portugal, and between the two rivers. Salinity and pollution seem to be the main factors that affected the biomarkers. Effects of chronic pollution were observed at the river mouths, and an indication of a possible temporary exposure to pollutants was found at the open ocean site in Portugal.

  13. Toxicity and QSAR of chlorobenzenes in two species of Benthic flatfish, flounder (Platichthys flesus L.) and sole (Solea solea L.)

    SciTech Connect

    Furay, V.J.; Smith, S.

    1995-01-01

    Chlorinated benzenes were among the first large-scale produced aromatic compounds. They have found broad spectrum of uses in numerous domestic and industrial preparations, ranging from engine - block cleaners, solvents, pharmaceutical intermediates, synthesis of chlorophenols and in disinfectants. Recent investigations have shown that they are present in the major environmental compartments and organisms, including fish tissues, coastal waters, and estuaries. Comparatively little is known about the ecotoxicity of chlorinated benzenes particularly to economically important fish. A number of earlier investigations examined the toxicity of chlorobenzenes and they demonstrated differences in the toxicity values for the same species and isomers of the chemicals investigated. The present investigation has assessed the toxicity and QSARs of selected chlorobenzenes to two ecologically and commercially important flatfish, the flounder (platichthys flesus) and sole (Solea solea). Both have a widespread geographic distribution in coastal and estuarine regions throughout Western Europe and are therefore highly representative test species. 20 refs., 5 tabs.

  14. Antimicrobial Activity of Peptides Derived from Olive Flounder Lipopolysaccharide Binding Protein/Bactericidal Permeability-Increasing Protein (LBP/BPI)

    PubMed Central

    Nam, Bo-Hye; Moon, Ji-Young; Park, Eun-Hee; Kim, Young-Ok; Kim, Dong-Gyun; Kong, Hee Jeong; Kim, Woo-Jin; Jee, Young Ju; An, Cheul Min; Park, Nam Gyu; Seo, Jung-Kil

    2014-01-01

    We describe the antimicrobial function of peptides derived from the C-terminus of the olive flounder LBP BPI precursor protein. The investigated peptides, namely, ofLBP1N, ofLBP2A, ofLBP4N, ofLBP5A, and ofLBP6A, formed α-helical structures, showing significant antimicrobial activity against several Gram-negative bacteria, Gram-positive bacteria, and the yeast Candida albicans, but very limited hemolytic activities. The biological activities of these five analogs were evaluated against biomembranes or artificial membranes for the development of candidate therapeutic agents. Gel retardation studies revealed that peptides bound to DNA and inhibited migration on an agarose gel. In addition, we demonstrated that ofLBP6A inhibited polymerase chain reaction. These results suggested that the ofLBP-derived peptide bactericidal mechanism may be related to the interaction with intracellular components such as DNA or polymerase. PMID:25329706

  15. Melanocortin receptor subtypes in interrenal cells and corticotropic activity of α-melanocyte-stimulating hormones in barfin flounder, Verasper moseri.

    PubMed

    Kobayashi, Yuki; Chiba, Hiroaki; Yamanome, Takeshi; Schiöth, Helgi B; Takahashi, Akiyoshi

    2011-02-01

    The aim of this study was to characterize the pituitary-interrenal axis in barfin flounder, a flatfish. Adrenocorticotropic hormone (ACTH) and melanocortin 2 receptor (MC2R) have been shown to be indispensable substances in pituitary and interrenal cells for cortisol release, respectively. We previously identified ACTH in the pars distalis of the barfin flounder pituitary gland, and detected transcripts of Mc1r, Mc4r, and Mc5r in the head kidney wherein interrenal cells are located. We have now demonstrated the presence of MC2R, which is a specific receptor for ACTH, in interrenal cells by molecular cloning of Mc2r cDNA and in situ hybridization, and confirmation of the in vitro cortisol-releasing activity of ACTH. These results show the presence of a classical pituitary-interrenal axis in this fish. We also evaluated the role of α-melanocyte-stimulating hormone (α-MSH) and its related peptides. In situ hybridization was used to demonstrate the expression of Mc5r in interrenal cells; both desacetyl-α-MSH and diacetyl-α-MSH showed in vitro cortisol-releasing activities, while the activity of α-MSH was negligible. These findings indicate the presence of an additional pituitary-interrenal axis consisting of α-MSH-like peptides secreted from the neurointermediate lobe of the pituitary and MC5R in the interrenal cells. The cortisol-releasing activity of desacetyl-α-MSH and diacetyl-α-MSH, compared with the low activity of α-MSH, suggest a unique and specific functional role of these forms of MSH peptides. The interrenal co-expression of two subtypes of Mcrs may play a role in this specialization.

  16. Transfer of benzo(a)pyrene from two invertebrate prey species to the winter flounder, Pleuronectes americanus

    SciTech Connect

    Schnitz, A.R.; Taghon, G.L.

    1995-12-31

    Anthropogenic activities in and around the estuarine environment may introduce compounds with the ability to move through trophic levels, resulting in adverse effects to ecosystems and human health. In order to observe the potential for transfer of the carcinogen benzo(a)pyrene (BaP) and its derivatives from prey organisms to a predator, a simplified benthic food chain was constructed. Winter flounder, Pleuronectes americanus, were fed via gavage either softshell clams, Mya arenaria, or sandworms, Neanthes virens, that had previously been exposed to {sup 14}C-benzo(a)pyrene-contaminated sediments and contained 5.05 ng/g and 5.8 ng/g activity, respectively (wet weight). The fish received doses every 48 hours for a total of 192 hours after which time, all tissues except the gall bladder were examined for the presence of BaP using liquid scintillation spectrometry (LSC). The bile was extracted with chloroform/methanol and analyzed via high performance liquid chromatography (HPLC) and LSC. The flounders that were fed worms demonstrated increased metabolism of the PAH relative to those fed clams, as shown by higher concentrations of polar metabolites in the bile. This corresponds with the higher concentration of metabolites recovered in the worm tissue; more than 95% of the recovered activity was in the form of polar derivatives whereas the activity in the clam tissue was almost completely parent benzo(a)pyrene. As was expected, the BaP metabolites formed by the fish were mediated by the differing abilities of the prey species to derivatize the PAH. Thus, macrofaunal interactions with sedimentary-associated polycyclic aromatic hydrocarbons may be important determinants in the fate and transport of these compounds in the benthos.

  17. Chronic effects of light irradiated from LED on the growth performance and endocrine properties of barfin flounder Verasper moseri.

    PubMed

    Takahashi, Akiyoshi; Kasagi, Satoshi; Murakami, Naoto; Furufuji, Sumihisa; Kikuchi, Shigeto; Mizusawa, Kanta; Andoh, Tadashi

    2016-06-01

    We investigated the effects of specific wavelengths of light on the growth of barfin flounder. The fish, reared in white tanks in a dark room, were irradiated with light from light-emitting diodes (LEDs) with peak wavelengths of 464nm (blue), 518nm (green), and 635nm (red) under a controlled photoperiod (10.5:13.5, light-dark cycle; 06:00-16:30, light). Fish were reared for four weeks in three independent experiments at three different water temperatures (averages of 14.9°C, 8.6°C, and 6.6°C). The fish irradiated with blue and green light had higher specific growth rates (% body weight⋅day(-1)) than fish irradiated with red light. Notably, green light had the greatest effect on growth among the three light wavelengths at 6.6°C. In the brains of fish reared at 6.6°C, the amounts of melanin-concentrating hormone 1 mRNA under green light were lower than those under red light, and amounts of proopiomelanocortin-C mRNA under blue and green light were higher than those under red light. No differences were observed for other neuropeptides tested. In the pituitary, no difference was observed in growth hormone mRNA content. In plasma, higher levels of insulin and insulin-like growth factor-I were observed in fish under green light than those of fish under red light. These results suggest that the endocrine systems of barfin flounder are modulated by a specific wavelength of light that stimulates somatic growth.

  18. Generation of Recombinant Viral Hemorrhagic Septicemia Virus (rVHSV) Expressing Two Foreign Proteins and Effect of Lengthened Viral Genome on Viral Growth and In Vivo Virulence.

    PubMed

    Kim, Min Sun; Lee, Su Jin; Kim, Dong Soo; Kim, Ki Hong

    2016-04-01

    In this study, a new recombinant VHSV (rVHSV-Arfp-Bgfp) was generated by insertion of a red fluorescent protein (RFP) gene between N and P genes, a green fluorescent protein (GFP) gene between P and M genes of VHSV genome, the expression of each heterologous gene in infected cells, and effects of the lengthened recombinant VHSV's genome on the replication ability and in vivo virulence to olive flounder (Paralichthys olivaceus) fingerlings were compared with previously generated rVHSVs (rVHSV-wild, rVHSV-Arfp, and rVHSV-Brfp). The expression of RFP and GFP in cells infected with rVHSV-Arfp-Bgfp was verified through fluorescent microscopy and FACS analysis. In the viral growth analysis, rVHSV-Arfp and rVHSV-Brfp showed significantly lower viral titers than rVHSV-wild, and the replication of rVHSV-Arfp-Bgfp was significantly decreased compared to that of even rVHSV-Arfp or rVHSV-Brfp. These results suggest that the genome length is a critical factor for the determination of rVHSVs replication efficiency. In the in vivo virulence experiment, the cumulative mortalities of olive flounder fingerlings infected with each rVHSV were inversely proportional to the length of the viral genome, suggesting that decreased viral growth rate due to the lengthened viral genome is accompanied with the decrease of in vivo virulence of rVHSVs. Recombinant viruses expressing multiple foreign antigens can be used for the development of combined vaccines. However, as the present rVHSV-Arfp-Bgfp still possesses an ability to kill hosts (although very weakened), researches on the producing more attenuated viruses or propagation-deficient replicon particles are needed to solve safety-related problems.

  19. Acute CO2 tolerance during the early developmental stages of four marine teleosts.

    PubMed

    Kikkawa, T; Ishimatsu, A; Kita, J

    2003-12-01

    Ocean sequestration of CO2 is proposed as a possible measure to mitigate climate changes caused by increasing atmospheric concentrations of the gas, but its impact on the marine ecosystem is unknown. We investigated the acute lethal effect of CO2 during the early developmental stages of four marine teleosts: red sea bream (Pagrus major), Japanese whiting (Sillago japonica), Japanese flounder (Paralichthys olivaceus), and eastern little tuna (Euthynnus affinis). The percentages of larvae that hatched and survived were not affected by exposure to water with a PCO2 of 1.0 kPa (= 7.5 mmHg) within 24 h. Median lethal PCO2 values for a 360-min exposure were 1.4 kPa (cleavage), 5.1 kPa (embryo), 7.3 kPa (preflexion), 4.2 kPa (flexion), 4.6 kPa (postflexion), and 2.5 kPa (juvenile) for red sea bream; 2.4 kPa (cleavage), 4.9 kPa (embryo), 5.9 kPa (preflexion), 6.1 kPa (flexion), 4.1 kPa (postflexion), and 2.7 kPa (juvenile) for Japanese whiting; 2.8 kPa (cleavage) and > 7.0 kPa (young) for Japanese flounder; and 11.8 kPa (cleavage) for eastern little tuna. Red sea bream and Japanese whiting of all ontogenetic stages had similar susceptibilities to CO2: the most susceptible stages were cleavage and juvenile, whereas the most tolerant stages were preflexion and flexion.

  20. Genetic polymorphism and its potential relation to environmental stress in five populations of the European flounder Platichthys flesus, along the French Atlantic coast.

    PubMed

    Marchand, J; Evrard, E; Guinand, B; Cachot, J; Quiniou, L; Laroche, J

    2010-08-01

    In this study, new DNA markers were explored for the flounder Platichthys flesus. cDNA and genomic sequences of the genes encoding the glyceraldehyde-3-phosphate-deshydrogenase (GAPDH), the cytosolic creatine kinase (CK), the prostaglandin D synthase (PGDS) and the betaine homocysteine methyltransferase (BHMT) were characterized. The tumour suppressor p53 gene structure was already described. A PCR-SSCP (Single Strand Conformation Polymorphism) analysis was finally conducted to study the genetic polymorphism of different populations of flounders collected along the French Atlantic coast. Four highly contaminated French estuaries (Seine, Vilaine, Loire and Gironde) were sampled and compared to a reference estuary (Ster) to explore possible selective effect of the environment on specific allelic frequencies. Our results showed that two loci p53 and PGDS, could be potential markers of chemical stress: p53A allele frequency increased in contaminated systems compared to the reference system. In the Vilaine estuary, PGDS polymorphism could be related to pesticide stress.

  1. Environmental genotoxicity and cytotoxicity in flounder (Platichthys flesus), herring (Clupea harengus) and Atlantic cod (Gadus morhua) from chemical munitions dumping zones in the southern Baltic Sea.

    PubMed

    Baršienė, Janina; Butrimavičienė, Laura; Grygiel, Wlodzimierz; Lang, Thomas; Michailovas, Aleksandras; Jackūnas, Tomas

    2014-05-01

    The data on environmental genotoxicity and cytotoxicity levels as well as on genotoxicity risk in flounder (Platichthys flesus), herring (Clupea harengus) and cod (Gadus morhua) collected in 2010-2012 at 42 stations located in chemical munitions dumping areas of the southern Baltic Sea are presented. The frequency of micronuclei, nuclear buds and nucleoplasmic bridges in erythrocytes was used as genotoxicity endpoint and the induction of fragmented-apoptotic, bi-nucleated and 8-shaped erythrocytes as cytotoxicity endpoint. The most significantly increased geno-cytotoxicity levels were determined in fish collected near known chemical munitions dumpsites. Extremely high genotoxicity risk for flounder were identified at 21 out of 24 stations, for herring at 29 out of 31 and for cod at 5 out of 10 stations studied. The reference level of genotoxicity was not recorded at any of the stations revealing that in the sampling area fish were affected generally.

  2. The importance of rivers as nursery grounds for 0- and 1-group flounder ( Platichthys flesus L.) in comparison to the Wadden sea

    NASA Astrophysics Data System (ADS)

    Kerstan, M.

    From May 1988 to June 1989 selected areas of the German Wadden Sea, the Ems, Weser, Elbe and Eider estuaries as well as in Elbe tributaries were sampled for 0- and 1-group flounder ( Platichthys flesus L.). Estuarine and Wadden Sea sampling was conducted on board commercial shrimp vessels equipped with beam trawls. The Elbe river system was sampled on board a research boat equipped with a similar 3-m beam trawl. Density indices were calculated for the various areas. To estimate the importance of rivers as nursery areas for flounder, river surface area was compared to the area of tidal flats in the Wadden Sea. In all surveys, there was no relationship between fish densities and tow directions with respect to tide. In the Elbe river system flounder densities were not correlated to substrate types but increased significantly with decreasing salinity. Abundances were always lowestt in polyhaline habitats and increased up to 10-fold in mesohaline estuarine areas. In the limnetic tidal sections of the Elbe river and its tributaries densities increased again by factors of 3 to 10. The succession of 1-group modal lengths from limnetic to polyhaline habitats demonstrated that smaller fish preferred less saline waters. 0-group specimens lagging behind in growth did not leave the limnetic river section in winter. The onset of the spawning migration in November was determined by monitoring the length-frequency distributions throughout the year. The possible sources of bias are discussed and gear efficiency is estimated from literature sources. The contribution of rivers to the 0- and 1-group flounder population on the tidal flats of the Wadden Sea is estimated at about 35.1%.

  3. Brominated flame retardants and organochlorine contaminants in winter flounder, harp and hooded seals, and North Atlantic right whales from the Northwest Atlantic Ocean.

    PubMed

    Montie, Eric W; Letcher, Robert J; Reddy, Christopher M; Moore, Michael J; Rubinstein, Belinda; Hahn, Mark E

    2010-08-01

    Various brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and current-use, non-PBDE BFRs, as well as organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were measured in winter flounder, harp and hooded seals, and North Atlantic right whales from the Eastern United States and Canada. The concentrations of PBDEs in winter flounder and right whales were similar in magnitude to the levels of PCBs, which was unlike the pattern observed in seals. In these marine mammals, the levels of PBDEs were orders of magnitude lower than the levels of OCs and PCBs detected. Evidence existed for the accumulation of methoxylated (MeO)-PBDEs of natural origin in seals and right whales. Current-use, non-PBDE BFRs (including hexabromocyclododecane, pentabromoethylbenzene, hexabromobenzene, and pentabromotoluene) were detected in winter flounder and marine mammals. Future research should focus on monitoring PBDEs, current-use, non-PBDE BFRs, and MeO-BDEs of natural origin in marine organisms from Massachusetts and Cape Cod Bays.

  4. Parasites of flounder Platichthys flesus (L.) from the German Bight, North Sea, and their potential use in ecosystem monitoring. B. Community structure and fish parasite biodiversity

    NASA Astrophysics Data System (ADS)

    Schmidt, V.; Zander, S.; Körting, W.; Steinhagen, D.

    2003-10-01

    The analysis of fish-parasite community structure and the use of ecological richness and diversity measurements are commonly used for the evaluation of environmental stress in aquatic ecosystems. As part of an integrated biological-effect monitoring, the parasite community of flounder Platichthys flesus (L.) was investigated for various locations in the German Bight during spring and autumn of 1995-2000, using established ecological methods. Although the parasite-community composition was very similar at the component-community level, the number of component species as well as the species accumulation curves showed clear differences among the sites. On the infra-community level, all of the ecological measurements showed significantly lower values in flounder from the Elbe estuary, the most polluted site, than in flounder from Helgoland. This was seen during a single season or during both seasons. When the data were pooled over the years, gradual differences between the sites, which were seldom detected at individual sampling periods, became evident for different measurements of species richness and species diversity and corresponded to a contamination gradient established between Elbe > Inner Eider, Outer Eider > Helgoland. Despite seasonal variations, which were observed in almost all measurements, these gradual differences were found in both seasons.

  5. DNA damage, EROD activity, condition indices, and their linkages with contaminants in female flounder (Platichthys flesus) from the southern Baltic Sea.

    PubMed

    Dabrowska, Henryka; Kopko, Orest; Góra, Agnieszka; Waszak, Ilona; Walkusz-Miotk, Jolanta

    2014-10-15

    The Baltic Sea is considered as one of the marine areas most exposed to human impacts. A variety of chemical contaminants pose a threat to the habitants. Female flounder (Platichthys flesus) collected from three locations in the southern Baltic Sea in February 2010 were examined for biomarkers of exposure to genotoxic agents (DNA damage), AhR-active contaminants (ethoxyresorufin-O-deethylase, EROD activity), and somatic condition indexes. Organochlorine contaminants (OCs) and polycyclic aromatic hydrocarbon (PAH) metabolites were also measured in individual flounder to evaluate the biological responses in the context of contaminant burden. The genotoxicity, mildly exceeding a background level, revealed a significant relationship with mono-ortho substituted PCB (m-oPCB). Hepatic EROD activity was highly induced, yet showed no association with any of the contaminants measured other than biliary 1-OH pyrene normalized to pigment absorbance. Significant negative relationships were observed for lipid-based OCs and the gonado-somatic index (GSI) as well as for Ʃm-oPCB concentrations and the condition factor (CF). Principal component analysis (PCA) revealed an overall connection between somatic condition indexes, biomarkers, and chemical variables. Of the three locations, flounder inhabiting the Gulf of Gdańsk had the greatest contaminant burden and appeared to be the most affected. Of great concern is the reduced GSI in this location which can be attributed to the effects of contaminants and warrants further investigation.

  6. Structural characterization of peptides derived from prosomatostatins I and II isolated from the pancreatic islets of two species of teleostean fish: the daddy sculpin and the flounder.

    PubMed

    Conlon, J M; Davis, M S; Falkmer, S; Thim, L

    1987-11-02

    The primary structures of three peptides from extracts from the pancreatic islets of the daddy sculpin (Cottus scorpius) and three analogous peptides from the islets of the flounder (Platichthys flesus), two species of teleostean fish, have been determined by automated Edman degradation. The structures of the flounder peptides were confirmed by fast-atom bombardment mass spectrometry. The peptides show strong homology to residues (49-60), (63-96) and (98-125) of the predicted sequence of preprosomatostatin II from the anglerfish (Lophius americanus). The amino acid sequences of the peptides suggest that, in the sculpin, prosomatostatin II is cleaved at a dibasic amino acid residue processing site (corresponding to Lys61-Arg62 in anglerfish preprosomatostatin II). The resulting fragments are further cleaved at monobasic residue processing sites (corresponding to Arg48 and Arg97 in anglerfish preprosomatostatin II). In the flounder the same dibasic residue processing site is utilised but cleavage at different monobasic sites takes place (corresponding to Arg50 and Arg97 in anglerfish preprosomatostatin II). A peptide identical to mammalian somatostatin-14 was also isolated from the islets of both species and is presumed to represent a cleavage product of prosomatostatin I.

  7. Differential sensitivity of flounder (Platichthys flesus) in response to oestrogenic chemical exposure: an issue for design and interpretation of monitoring and research programmes.

    PubMed

    Kirby, M F; Smith, A J; Barry, J; Katsiadaki, I; Lyons, B; Scott, A P

    2006-10-01

    This study was conducted as an initial investigation of 'differential response' in one of the main sentinel organisms used for monitoring programmes in United Kingdom estuaries, the flounder Platichthys flesus. It has been hypothesised that monitoring using species with a wide geographical spread and limited migration, such as flounder, might result in the comparison of different genetic stocks and certainly of populations with differing early life stage contaminant exposure histories. Furthermore, it is probable that these pre-exposure and genetic differences could manifest themselves in an ability to respond differently to contaminant exposure, so-called 'differential response'. It is important that the extent and nature of this response is understood, if we want to be able to fully interpret the monitoring data from such programmes. During this study, flounder were collected from four separate sources; wild caught fish from the estuaries of the Rivers Alde, Mersey and Tyne, and farmed flounder from Port Erin Farm, Isle of Man. Under controlled laboratory conditions, groups of fish from each source were exposed to water-borne concentrations of the synthetic oestrogen ethynylestradiol (EE2) at a nominal concentration of 50 ng/l. Plasma was taken from each male fish after 6 and 10 days exposure and analysed for the presence of vitellogenin (VTG) using an ELISA technique. Significant levels of VTG induction were evident in fish from all sources after both 6 and 10 days exposure. Flounder from the Mersey were the only fish with significantly elevated initial background levels of VTG (day 0) and this appeared to be reflected in that these specimens showed the highest induction response after day 6. However, after day 10, fish from all other sites had a slightly higher mean VTG than those from the Mersey which showed significantly (p < 0.05) lower mean plasma VTG. It is suggested that other differential responses may have been masked by the use of a high dose of EE2

  8. Density, growth and annual food consumption of plaice (Pleuronectes platessa L.) and flounder (Platichthys flesus (L.)) in Lake Grevelingen, The Netherlands

    NASA Astrophysics Data System (ADS)

    Doornbos, G.; Twisk, F.

    Within the scope of a carbon budget study in the 108 km 2 saline Lake Grevelingen, investigations on the plaice and flounder populations were made during October 1979 to December 1981. Both populations were dominated by the 1979 year class that presumably entered the lake as larvae in the year the Brouwerssluice, which opens to the North Sea, was operative the whole year round. Due to high summer temperatures in the lake, juvenile plaice (year class 1981) attained a mean length of 13.0 cm and a fresh weight of 27.4 g at the end of their first growing season. At the end of their third year, year class 1979 males measured on average 27.7 cm and females 29.7 cm, which is about 3.5 cm more than plaice of the same age in the North Sea. Flounder reached a mean length of 26.3 cm in 3 years. Total stock of plaice, excluding year class 1981, was estimated at an average of 1.3 million over 1980 and at 0.6 million fish over 1981. For flounder these figures were 0.7 million and 0.2 million and 0.2 million fish, respectively. In September 1981 the number of O-group plaice was assessed at about 0.2 million individuals. About 56% of the plaice food consisted of polychaetes, mainly consisting of in 1980 Arenicola marina (41%) and in 1981 A. marina (15%), Nereidae (15%) and Nephtys hombergii (11%). Larger plaice consumed significantly more Arenicola and less Tharyx marioni than smaller ones. Polychaetes and crustaceans were eaten the whole year rounf while the consumption of molluscs was restricted to the summer period and the of fisg to autumn and winter. In 1980 the flounder population preyed predominantly upon crustaceans (41%) and polychaetes (37%), with Arenicola marina (36%) and Crangon crangon (25%) as the most important species. In 1981 relatively more polychaetes (53%) and less crustaceans (14%) were eaten. Total consumption of plaice population, excluding year class 1981, in 1980 and 1981 was estimated at 1.68 g and 1.41 g ADW·m -2·a -1. Annual consumption of O

  9. Bioaccumulation and detoxication of nodularin in tissues of flounder (Platichthys flesus), mussels (Mytilus edulis, Dreissena polymorpha), and clams (Macoma balthica) from the northern Baltic Sea.

    PubMed

    Sipiä, V O; Kankaanpää, H T; Pflugmacher, S; Flinkman, J; Furey, A; James, K J

    2002-10-01

    Cyanobacterial hepatotoxin accumulation in mussels (Mytilus edulis, Dreissena polymorpha), clam (Macoma balthica), and flounder (Platichthys flesus) tissues was measured. Flounder were caught with gillnets from the western Gulf of Finland on 21 August 1999, 25 July 2000, and 25 August 2000. Blue mussels were collected from: (1) a steel cage at a depth of 3 m on 20 August 1999, (2) an enclosure at depths of 3-5 m, and (3) an artificial reef (wreck at 25-30 m) in the western Gulf of Finland between June and September 2000. Furthermore, blue mussels were collected from two sites between August and October 2000: south of the town of Hanko at depths of 5 and 20 m in the western Gulf of Finland and south of the city of Helsinki at a depth of 7 m in the central Gulf of Finland. M. balthica and D. polymorpha were collected at a depth of 12 m from Russian waters in the eastern Gulf of Finland on 1-4 August 2000. The samples were analyzed for the cyanobacterial hepatotoxins nodularin (NODLN) and microcystins (MCs) using enzyme-linked immunosorbent assay (ELISA), liquid chromatography-mass spectrometry (LC-MS), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). ELISA indicated a time-dependent accumulation of hepatotoxins in flounder liver up to 400 +/- 10 (SD) microg/kg on 25 August 2000. No hepatotoxins were detected in flounder muscle samples. In blue mussels, collected from an enclosure 3-5 m deep in the western Gulf of Finland on 23 August 2000, ELISA indicated cyanobacterial hepatotoxins up to 1490 +/- 60 microg/kg dry wt. Blue mussels collected from the other sites contained less cyanobacterial hepatotoxins (40-130 microg/kg dry wt). Clams and mussels from Russian waters contained cyanobacterial hepatotoxin at about 100-130 microg/kg dry wt. Total hepatotoxin levels in mussels from enclosures decreased from August to September, indicating at least partial detoxication/depuration of the toxins. LC-MS verified the presence of

  10. Long-term exposure of European flounder (Platichthys flesus) to the flame-retardants tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD).

    PubMed

    Kuiper, R V; Cantón, R F; Leonards, P E G; Jenssen, B M; Dubbeldam, M; Wester, P W; van den Berg, M; Vos, J G; Vethaak, A D

    2007-07-01

    Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are widely used flame retardants that have increasingly been found as contaminants in the aquatic environment. In the present study, European flounder (Platichthys flesus) were chronically exposed to TBBPA; (105 days) and HBCD (78 days), in a wide range including environmentally relevant concentrations. TBBPA was administered via the water, whereas HBCD was administered in food and sediment, or in sediment alone. Chemical analysis of muscle showed an average increase in internal concentrations of approximately two orders of magnitude for both compounds tested. Animals exposed to HBCD via sediment alone (8000 microg/g total organic carbon, TOC) showed a proportional increase of alpha-HBCD in muscle compared to animals exposed via food and sediment. In both studies, exposure to the test compounds did not affect general health and toxicity parameters (behavior, survival, growth rate, relative liver and gonad weight). Hepatic microsomal enzyme activities (TBBPA: EROD; HBCD: EROD, PROD, and BROD) were not induced by any of the tested chemicals. Aromatase activity in male gonads showed a mild increase with rising TBBPA levels. There were no morphological and immunohistochemical indications for increased production of the yolk precursor protein vitellogenin (VTG) in animals exposed to TBBPA and HBCD; immunochemical analysis of plasma VTG levels showed no dose response in animals exposed to TBBPA. In animals exposed to TBBPA, levels of the thyroid hormone thyroxin (T(4)) increased with internal concentrations of the test compound, possibly indicating competition of TBBPA for plasma protein binding. Triiodothyronin (T(3)) levels were not affected and histology showed no signs of altered thyroid gland activity. Other organs investigated (liver, gills, kidney, skin, and gonads) revealed no histological changes related to TBBPA or HBCD exposure. Overall, the present results indicate limited endocrine effects of

  11. Evidences for involvement of growth hormone and insulin-like growth factor in ovarian development of starry flounder (Platichthys stellatus).

    PubMed

    Xu, Yongjiang; Wang, Bin; Liu, Xuezhou; Shi, Bao; Zang, Kun

    2017-04-01

    Although gonadotrophins are major regulators of ovarian function in teleosts and other vertebrates, accumulating evidence indicates that the growth hormone (GH)-insulin-like growth factor (IGF) axis also plays an important role in fish reproduction. As a first step to understand the physiological role of the GH-IGF system in the ovarian development of starry flounder (Platichthys stellatus), the expression profiles of GH and IGF messenger RNAs (mRNAs) and plasma GH, IGF-I, estradiol-17β (E2), and testosterone (T) levels during the ovarian development were investigated. The developmental stages of ovaries were divided into five stages (II, III, IV, V, and VI) by histological analysis. The hepatosomatic index (HSI) and gonadosomatic index (GSI) values increased and peaked at stage IV and stage V, respectively, and then declined at stage VI. Pituitary GH mRNA levels decreased sharply at stage III and raised to top level at stage VI. The hepatic IGF-I mRNA levels ascended to maximum value at stage V and then declined significantly at stage VI. However, the hepatic IGF-II mRNA levels remained stable and increased significantly at stage VI. In contrast, the ovarian IGF-I mRNA levels increased gradually and peaked at stage VI. The ovarian IGF-II mRNA levels were initially stable and increased significantly at stage V until the top level at stage VI. Consistent with the pituitary GH mRNA levels, plasma GH levels reduced sharply at stage III and remained depressed until stage V and then raised remarkably at stage VI. Plasma IGF-I level peaked at stage V and then declined to initial level. Plasma E2 level peaked at stage IV and then dramatically descended to the basal level. Plasma T level peaked at stage V and then declined significantly back to the basal level. Based on statistical analysis, significant positive correlations between hepatic IGF-I mRNA and GSI, ovarian IGF-II mRNA and hepatic IGF-II mRNA, ovarian IGF-I mRNA and ovarian IGF-II mRNA, and plasma IGF-I and

  12. Potential of mean force calculation of the free energy of adsorption of Type I winter flounder antifreeze protein on ice

    NASA Astrophysics Data System (ADS)

    Battle, Keith; Alan Salter, E.; Wesley Edmunds, R.; Wierzbicki, Andrzej

    2010-04-01

    Antifreeze proteins (AFPs) are a unique class of proteins that inhibit ice growth without changing the melting point of ice. In this work, we study the detailed molecular mechanism of interactions between the hydrophobic side of the winter flounder (WF) AFP and two mutants, AAAA and SSSS, in which threonine residues are substituted by serines and alanines, respectively. Umbrella sampling molecular dynamics simulations of the separation of the proteins from the (2 0 1) surface in an explicit water box is carried out to calculate the potential of mean force free energies of adsorption using AMBER10i. We estimate wild-type WF's free energy of adsorption to ice to be about -12.0 kcal/mol. Gas-phase pseudopotential plane-wave calculations of methane adsorption onto select surfaces of ice are also carried out under periodic boundary conditions to address the possible enthalpic role of WF's methyl groups in binding. The contributions of hydrophobic residues to the free energy of adsorption are discussed.

  13. Responses of the European flounder (Platichthys flesus) to a mixture of PAHs and PCBs in experimental conditions.

    PubMed

    Dupuy, Célie; Galland, Claire; Devaux, Alain; Bony, Sylvie; Loizeau, Véronique; Danion, Morgane; Pichereau, Vianney; Fournier, Michel; Laroche, Jean

    2014-12-01

    A multibiomarker approach was developed to evaluate the juvenile European flounder responses to a complex mixture of 9 polycyclic aromatic hydrocarbons (PAHs) and 12 polychlorinated biphenyls (PCBs). Exposure was performed through contaminated food pellets displaying: (1) PAH and PCB levels similar to those detected in the heavily polluted Seine estuary, respectively in sediments and in flatfish and (2) ten times these concentrations. Several biomarkers of the immune system (e.g., lysozyme concentration and gene expression of complement component C3 and TNF-receptor), DNA damage (e.g., Comet assay), energetic metabolism (e.g., activity of cytochrome C oxidase), detoxification process (e.g., cytochrome P450 1A1 expression level: CYP1A1; betaine homocysteine methyl transferase expression level: BHMT) were investigated after 14 and 29 days of contamination, followed by a 14-days recovery period. After 29 days of contamination, the detoxification activity (CYP1A1 expression level) was positively correlated with DNA damages; the increase of the BHMT expression level could also be related to the detoxification process. Furthermore, after the recovery period, some biomarkers were still upregulated (i.e., CYP1A1 and BHMT expression levels). The immune system was significantly modulated by the chemical stress at the two concentration levels, and the lysozyme appeared to be the most sensitive marker of the mixture impact.

  14. Oral single pulse exposure of flounder Platichthys flesus to 4-tert-octylphenol: Relations between tissue levels and estrogenic effects.

    PubMed

    Madsen, Louise L; Korsgaard, Bodil; Bjerregaard, Poul

    2006-04-01

    The accumulation of 4-tert-octylphenol and the associated estrogenic effects were studied after a single pulse exposure to flounder Platichthys flesus. 4-tert-octylphenol was administered orally in a single dose of 50 mg kg(-1) and tissue (liver, muscle and testis) and plasma concentrations of 4-tert-octylphenol as well as plasma vitellogenin were measured 3, 6, 12, 18, 24, 48, 72, 144 and 216 h after administration of the dose. Concentrations of 4-tert-octylphenol in plasma and tissues were determined by Liquid Chromatography Mass Spectrometry (LC-MS). 4-tert-octylphenol was detectable in liver, testis, muscle and plasma 3h post administration and an accumulation was observed in liver, muscle and plasma up to 12 h and in testis 18 h post administration, respectively. The maximum concentrations of 4-tert-octylphenol in liver, muscle and testis were 67, 3.2 and 6.8 microg g(-1), respectively. An increase in plasma vitellogenin levels was seen 48 h post administration and the vitellogenin level continued to increase (from <100 ng ml(-1) to 1.4 mg ml(-1)) until the end of the experiment 9 days after the administration of 4-tert-octylphenol.

  15. Molecular Characterization and Expression of α-Globin and β-Globin Genes in the Euryhaline Flounder (Platichthys flesus).

    PubMed

    Lu, Weiqun; Mayolle, Aurelie; Cui, Guoqiang; Luo, Lei; Balment, Richard J

    2011-01-01

    In order to understand the possible role of globin genes in fish salinity adaptation, we report the molecular characterization and expression of all four subunits of haemoglobin, and their response to salinity challenge in flounder. The entire open reading frames of α1-globin and α2-globin genes were 432 and 435 bp long, respectively, whereas the β1-globin and β2-globin genes were both 447 bp. Although the head kidney (pronephros) is the predicted major site of haematopoiesis, real-time PCR revealed that expression of α-globin and β-globin in kidney (mesonephros) was 1.5 times higher than in head kidney. Notably, the α1-globin and β1-globin mRNA expression was higher than α2-globin and β2-globin in kidney. Expression levels of all four globin subunits were higher in freshwater- (FW-) than in seawater- (SW-)adapted fish kidney. If globins do play a role in salinity adaptation, this is likely to be more important in combating the hemodilution faced by fish in FW than the dehydration and salt loading which occur in SW.

  16. Molecular identification and expression of differentially regulated genes of the European flounder, Platichthys flesus, submitted to pesticide exposure.

    PubMed

    Marchand, J; Tanguy, A; Charrier, G; Quiniou, L; Plee-Gauthier, E; Laroche, J

    2006-01-01

    Effects of pesticide exposure on the European flounder, Platichthys flesus, were investigated using a suppression subtractive hybridization method (SSH) to identify up- and down-regulated genes after a 30-day exposure to herbicides (a cocktail of atrazine, diuron, and isoproturon, and a single herbicide, glyphosate). A total of 256 expressed gene sequences were identified as having the potential for being differentially expressed, of which 116 could be identified by homology with databased sequences. The metabolic functions with which they are associated include energy production, general metabolism, signaling, transport, immune system, and structure. Expression of 14 of these genes was analyzed in liver, muscle, and gills by reverse transcriptase-polymerase chain reaction (RT-PCR) under experimental conditions (0, 15, and 30 days of exposure) and under field conditions (sampling in two estuaries displaying different levels of pesticide contamination). This study provides a first basis for studying the response of fish to pesticide exposure and allows the characterization of new potential genetic markers of pesticide contamination in the field.

  17. Development of the GENIPOL European flounder (Platichthys flesus) microarray and determination of temporal transcriptional responses to cadmium at low dose.

    PubMed

    Williams, Tim D; Diab, Amer M; George, Stephen G; Godfrey, Rita E; Sabine, Victoria; Conesa, Ana; Minchin, Steven D; Watts, Phil C; Chipman, James K

    2006-10-15

    We have constructed a high density, 13 270-clone cDNA array for the sentinel fish species European flounder (Platichthys flesus), combining clones from suppressive subtractive hybridization and a liver cDNA library; DNA sequences of 5211 clones were determined. Fish were treated by single intraperitoneal injection with 50 micrograms cadmium chloride per kilogram body weight, a dose relevant to environmental exposures, and hepatic gene expression changes were determined at 1, 2, 4, 8, and 16 days postinjection in comparison to saline-treated controls. Gene expression responses were confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR). Blast2GO gene ontology analysis highlighted a general induction of the unfolded protein response, response to oxidative stress, protein synthesis, transport, and degradation pathways, while apoptosis, cell cycle, cytoskeleton, and cytokine genes were also affected. Transcript levels of cytochrome P450 1A (CYP1A) were repressed and vitellogenin altered, real-time PCR showed induction of metallothionein. We thus describe the establishment of a useful resource for ecotoxicogenomics and the determination of the temporal molecular responses to cadmium, a prototypical heavy metal pollutant.

  18. Complete genome sequence of Vibrio parahaemolyticus strain FORC_008, a foodborne pathogen from a flounder fish in South Korea.

    PubMed

    Kim, Suyeon; Chung, Han Young; Lee, Dong-Hoon; Lim, Jong Gyu; Kim, Se Keun; Ku, Hye-Jin; Kim, You-Tae; Kim, Heebal; Ryu, Sangryeol; Lee, Ju-Hoon; Choi, Sang Ho

    2016-07-01

    Vibrio parahaemolyticus is a Gram-negative, motile, nonspore-forming pathogen that causes foodborne illness associated with the consumption of contaminated seafoods. Although many cases of foodborne outbreaks caused by V. parahaemolyticus have been reported, the genomes of only five strains have been completely sequenced and analyzed using bioinformatics. In order to characterize overall virulence factors and pathogenesis of V. parahaemolyticus associated with foodborne outbreak in South Korea, a new strain FORC_008 was isolated from flounder fish and its genome was completely sequenced. The genomic analysis revealed that the genome of FORC_008 consists of two circular DNA chromosomes of 3266 132 bp (chromosome I) and 1772 036 bp (chromosome II) with a GC content of 45.36% and 45.53%, respectively. The entire genome contains 4494 predicted open reading frames, 129 tRNAs and 31 rRNA genes. While the strain FORC_008 does not have genes encoding thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH), its genome encodes many other virulence factors including hemolysins, pathogenesis-associated secretion systems and iron acquisition systems, suggesting that it may be a potential pathogen. This report provides an extended understanding on V. parahaemolyticus in genomic level and would be helpful for rapid detection, epidemiological investigation and prevention of foodborne outbreak in South Korea.

  19. Establishment and characterization of a new marine fish cell line from ovary of barfin flounder ( Verasper moseri)

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohui; Fan, Tingjun; Jiang, Guojian; Yang, Xiuxia

    2015-12-01

    A novel continuous ovary cell line from barfin flounder ( Verasper moseri) (BFO cell line) was established with its primitive application in transgenic expression demonstrated in this study. Primarily cultured cells grew well at 22°C in Dulbecco's modified Eagle medium/F12 medium (DMEM/F12, 1:1; pH 7.2) supplemented with 20% fetal bovine serum (FBS), carboxymethyl chitooligosaccharide, basic fibroblast growth factor (bFGF) and insulin-like growth factor-I (IGF-I). The primary BFO cells in fibroblastic morphology proliferated into a confluent monolayer about 2 weeks later, and were able to be subcultured. Impacts of medium and temperature on the growth of the cells were examined. The optimum growth was found in DMEM/F12 with 20% FBS and at 22°C. The BFO cells can be continuously subcultured to Passage 120 steadily with a population doubling time of 32.7 h at Passage 60. Chromosome analysis revealed that 72% of BFO cells at Passage 60 maintained the normal diploid chromosome number (46) with a normal karyotype of 2st+44t. The results of gene transformation indicated that green fluorescence protein (GFP) positively expressed in these cells after being transformed with pcDNA3.1-GFP. Therefore, a continuous and transformable BFO cell line was successfully established, which may serve as a useful tool for cytotechnological manipulation and transgenic modification of this fish.

  20. Immigration and early life stages recruitment of the European flounder (Platichthys flesus) to an estuarine nursery: The influence of environmental factors

    NASA Astrophysics Data System (ADS)

    Amorim, Eva; Ramos, Sandra; Elliott, Michael; Bordalo, Adriano A.

    2016-01-01

    Connectivity between coastal spawning grounds and estuarine nurseries is a critical step in the life cycle of many fish species. Larval immigration and transport-associated physical-biological processes are determinants of recruitment success to nursery areas. The recruitment of the European flounder, Platichthys flesus, to estuarine nurseries located at the southern edge of the species distribution range, has been usually investigated during its juvenile stages, while estuarine recruitment during the earlier planktonic life stage remains largely unstudied. The present study investigated the patterns of flounder larval recruitment and the influence of environmental factors on the immigration of the early life stages to the Lima estuary (NW Portugal), integrating data on fish larvae and post-settlement individuals (< 50 mm length), collected over 7 years. Late-stage larvae arrived at the estuary between February and July and peak abundances were observed in April. Post-settlement individuals (< 50 mm) occurred later between April and October, whereas newly-settled ones (< 20 mm) were found only in May and June. Variables associated with the spawning, survival and growth of larvae in the ocean (sea surface temperature, chlorophyll a and inland hydrological variables) were the major drivers of flounder occurrence in the estuarine nursery. Although the adjacent coastal area is characterized by a current system with strong seasonality and mesoscale variability, we did not identify any influence of variables related with physical processes (currents and upwelling) on the occurrence of early life stages in the estuary. A wider knowledge on the influence of the coastal circulation variability and its associated effects upon ocean-estuarine connectivity is required to improve our understanding of the population dynamics of marine spawning fish that use estuarine nurseries.

  1. Relationship between sex steroid and vitellogenin concentrations in flounder (Platichthys flesus) sampled from an estuary contaminated with estrogenic endocrine-disrupting compounds.

    PubMed

    Scott, Alexander P; Katsiadaki, Ioanna; Kirby, Mark F; Thain, John

    2006-04-01

    High concentrations of vitellogenin (VTG; egg yolk protein) have previously been found in male flounder (Platichthys flesus) from several UK estuaries; these levels have been ascribed to the presence of estrogenic endocrine-disrupting compounds (EDCs). Gonadal abnormalities, including intersex, have also been recorded in these estuaries. However, there is no firm evidence to date that these two findings are causally linked or that the presence of estrogenic EDCs has any adverse population effects. In the present study, we examined the relationship between concentrations of VTG and sex steroids (11-oxo-testosterone in males and 17beta-estradiol in females) in specimens of flounder captured from the estuary of the River Mersey. We first questioned whether the high concentrations of VTG in male and immature female flounder were indeed caused by a direct effect of exogenous EDCs and not indirectly via the endogenous secretion of 17beta-estradiol. The data favored the direct involvement of estrogenic EDCs. We then questioned whether the presence of estrogenic EDCs not only stimulated inappropriate VTG synthesis but whether it might also have had a negative effect on endogenous steroid secretion. It should be noted that the predicted consequences of a drop in steroid secretion include smaller gonads, smaller oocytes, fewer numbers of sperm, and depressed spawning behavior. This question was more difficult to answer because of the strong effect of the seasonal reproductive cycle and stage of maturation on steroid concentrations. However, matched by month of capture and stage of maturation, both 17beta-estradiol in females and 11-keto-testosterone in males were in most cases significantly lower in those years when VTG concentrations were higher.

  2. Seasonal changes in peptide, receptor and ion channel mRNA expression in the caudal neurosecretory system of the European flounder (Platichthys flesus).

    PubMed

    Lu, Weiqun; Worthington, Jonathan; Riccardi, Daniela; Balment, Richard J; McCrohan, Catherine R

    2007-01-01

    The caudal neurosecretory system (CNSS) of the euryhaline flounder Platichthys flesus has suggested roles in osmoregulatory, reproductive and nutritional adaptation, as fish migrate between seawater (winter) and brackish/freshwater (summer) environments. This study examined seasonal changes in mRNA expression profile of functionally important genes in the CNSS. cDNAs encoding neuropeptides, receptors and ion channels were cloned by reverse transcriptase polymerase chain reaction (RT-PCR) and screening of a flounder CNSS cDNA library. The expression profile of cloned genes was determined by real-time RT-PCR at 2-month intervals throughout the year in CNSS from seawater-adapted fish. Plasma cortisol (measured by radioimmunoassay) showed a peak in April, the time of spawning. Expression levels of mRNA for peptides urotensins I and II (UI, UII) and corticotropin releasing factor (CRF) all showed a seasonal cycle, with lowest expression in April and highest in August-October. The expression of CRF2(UI), UT(UII) and CRF1 receptors was not correlated with corresponding peptide expression. Receptors for potential neuromodulators of CNSS activity also displayed a seasonal mRNA expression profile. Glucocorticoid, 5-hydroxytryptamine, kappa-opioid and glutamate receptor expression peaked around April, suggesting that modulation of electrical activity of the neurosecretory Dahlgren cells is of particular importance at this time. Expression of mRNA for L-type Ca(2+) and Ca-activated K(+) channels was lower during the summer months. These channels underlie electrical bursting activity in Dahlgren cells. Ion channel mRNA expression was also lower in CNSS from flounder fully adapted to freshwater as opposed to seawater, consistent with previously reported observations of reduced bursting activity in Dahlgren cells from freshwater-adapted CNSS. These findings support the hypothesis that the CNSS is functionally reprogrammed to cope with changes in physiological challenge as fish

  3. Hepatic transcriptomic profiles of European flounder (Platichthys flesus) from field sites and computational approaches to predict site from stress gene responses following exposure to model toxicants.

    PubMed

    Falciani, F; Diab, A M; Sabine, V; Williams, T D; Ortega, F; George, S G; Chipman, J K

    2008-11-11

    Genomic technologies offer opportunities to gain a more global assessment of the health status of an organism through an understanding of the functional pathways that are responding to pollutant exposure. We have developed a 13,000 clone cDNA toxicogenomics microarray for Platichthys flesus, the European flounder (EU-GENIPOL Project). We aimed to distinguish the origins of flounder taken from six sampling sites of different pollution status in Northern Europe according to their hepatic gene expression profile using bioinformatic approaches. To determine which gene expression differences may relate to pollutant impact, we have completed complementary laboratory exposures of flounder to selected toxicants and determined the associated gene expression profiles. Using multivariate variable selection coupled with a statistical modelling procedure (GALGO) we can predict geographical site but the accuracy is limited to specific sites. The search space for a combination of genes that effectively predicts class membership is very large, however, by combining the signatures derived from acute laboratory exposure to individual chemicals to limit the search space, a very accurate model for classification of all the different environmental sites was achieved. The final model utilised the expression profiles of 16 clones and validation with a qPCR array comprising these genes correctly assigned the site of origin for fish obtained from three of the sites in an independent sampling. These data would imply that the gene expression fingerprints obtained with these arrays are primarily attributable to variations in chemical pollutant responses at the different sites, indicating their potential utility in environmental impact assessment.

  4. Surveys of plasma vitellogenin and intersex in male flounder (Platichthys flesus) as measures of endocrine disruption by estrogenic contamination in United Kingdom estuaries: temporal trends, 1996 to 2001.

    PubMed

    Kirby, Mark F; Allen, Yvonne T; Dyer, Robert A; Feist, Steve W; Katsiadaki, Ioanna; Matthiessen, Peter; Scott, Alex P; Smith, Andrew; Stentiford, Grant D; Thain, John E; Thomas, Kevin V; Tolhurst, Laura; Waldock, Michael J

    2004-03-01

    Plasma vitellogenin (VTG) concentrations and the presence of the ovo-testis (intersex) condition have been recorded in male flounder (Platichthys flesus) captured from several United Kingdom (UK) estuaries since 1996 as part of the endocrine disruption in the Marine Environment (EDMAR) project and earlier programs. It has been confirmed that plasma VTG concentrations in male flounder have remained elevated in several UK estuaries (e.g., Tees, Mersey, and Tyne) throughout the period covered by this study. However, the time-series data indicate that plasma VTG, a measure of environmental estrogen contamination, has decreased in fish captured from several estuaries, especially those of the Tyne and Mersey. Shorter time-series data sets from the Forth and Clyde estuaries also suggest a decrease in estrogen contamination at these sites. Trends associated with specific point sources of estrogenic contamination show site-specific patterns. For instance, plasma VTG levels in male flounder captured near the Howdon sewage treatment outfall (Tyne) have shown a steady decline to near baseline levels in 2001, while the plasma of male fish captured at a site adjacent to the Dabholm Gut discharge in the Tees estuary have shown little evidence of a sustained decline. The occurrence of the intersex condition was detected at a low but consistent prevalence through the study period, with the majority of cases recorded in fish captured from the Tyne and Mersey estuaries. The data set does not allow conclusions to be drawn about any temporal trends associated with this condition. The significance of the findings and possible mitigating influences are discussed in terms of the impacts on wild fish and the role of effluent treatment in reducing these.

  5. Toxicity of analytically cleaned pentabromodiphenylether after prolonged exposure in estuarine European flounder (Platichthys flesus), and partial life-cycle exposure in fresh water zebrafish (Danio rerio).

    PubMed

    Kuiper, Raoul V; Vethaak, A D; Cantón, Roćio F; Anselmo, Henrique; Dubbeldam, Marco; van den Brandhof, Evert-Jan; Leonards, Pim E G; Wester, Piet W; van den Berg, Martin

    2008-09-01

    Residues of polybrominated diphenylethers (PBDEs), extensively applied as flame retardants, are widely spread in the aquatic environment and biota. The present study investigates effects of the environmentally relevant lower brominated diphenylethers in two fish species in vivo under controlled laboratory conditions. Euryhaline flounder (Platichthys flesus) and freshwater zebrafish (Danio rerio) were exposed to a range of concentrations of a commercial pentabromodiphenylether mixture, DE-71. Chemical analysis of exposed fish showed a pattern of PBDE congeners that was very similar to that in wild fish. The resulting range included environmentally relevant, as well as higher levels. Animals were investigated histopathologically with emphasis on endocrine and reproductive organs. In zebrafish, hatching of embryos and larval development were assessed. Biochemical parameters were investigated in flounder as markers for suggested dioxin-like activity (ethoxyresorufin-O-deethylase=EROD), and activation of endogenous estrogen synthesis (gonad aromatase activity). Thyroid hormones were analyzed in plasma in both species. Benchmark analysis using internal PBDE concentrations showed a mild dose-dependent decrease of hepatic EROD and ovarian aromatase activities, and plasma thyroxin levels in flounder, and an increase of plasma thyroid hormone levels in zebrafish. These trends did not result in statistically significant differences from control fish, and major histopathological changes were not observed. Reproduction in zebrafish appeared to be the most sensitive parameter with statistically significantly reduced larval survival and non-significant indications for decreased egg production at internal levels that were more than 55 times the highest environmental recordings. The present results indicate limited risk for endocrine or reproductive effects of current environmental PBDE contamination in fish.

  6. Altered plasma and pituitary arginine vasotocin and hypothalamic provasotocin expression in flounder (Platichthys flesus) following hypertonic challenge and distribution of vasotocin receptors within the kidney.

    PubMed

    Warne, J M; Bond, H; Weybourne, E; Sahajpal, V; Lu, W; Balment, R J

    2005-12-01

    Plasma AVT concentration, pituitary AVT content, hypothalamic provasotocin mRNA expression and other osmoregulatory parameters were measured in euryhaline flounder 4, 8, and 24 h after the hypertonic challenge of transfer from fresh water (FW) to seawater (SW). Osmolality and the concentration of major plasma ions, sodium and chloride, were significantly higher in fish transferred to SW by comparison with time matched controls, an effect evident within 4 h. By comparison with time matched controls, pituitary store of AVT was lower while plasma AVT concentration was higher 8 and 24 h after transfer to SW. Higher provasotocin mRNA expression in the hypothalamus was also seen at 4 and 8 h in flounder transferred from FW to SW compared with time matched controls. The lower pituitary store and higher circulating levels imply substantial AVT secretion occurs in the early phase response to this hypertonic challenge. Changes in the regulation of AVT synthesis and secretion appeared quickly following movement to SW, consistent with the rapid osmoregulatory response, including reduced urine production that fish require to accommodate the dehydrative water losses and salt loading on exposure to the new hyperosmotic environment. qPCR measures of whole kidney vasotocin receptor mRNA expression indicated similar levels in SW and FW. Immunohistochemistry for the vasotocin receptor in flounder kidney showed localisation on the afferent and efferent arterioles of the glomerulus and on the capillary bed that extends from the efferent arteriole to the smooth muscle surrounding the collecting duct. Localisation of the vasotocin receptor was comparable in SW and FW fish.

  7. Disease prevalence in flounder (Platichthys flesus) from the Dutch Wadden Sea as indicator of environmental quality: A summary of 1988-2005 surveys

    NASA Astrophysics Data System (ADS)

    Vethaak, A. D.

    2013-09-01

    In 1988, epizootics of ulcer disease in the flatfish flounder in the Dutch Wadden Sea were reported near freshwater drainage sluices of IJsselmeer Lake, locally affecting up to 38.9% of fish. Other diseases such as fin rot and lymphocystis were less frequent, but followed a similar pattern. Results of follow-up surveys in the Wadden Sea in 1994-2005 confirm previous findings and also show significantly elevated ulcer prevalences at other smaller drainage works. The most likely stress factors that contributed to the development of the epizootics at these sites include osmotic stress, adverse water quality conditions including chemical contaminants, nutritional deficiencies, and obstruction to fish migration. It was shown that discharges of IJsselmeer Lake freshwater in 1988-96 had a wide effect on the prevalence and distribution of ulcers and lymphocystis in the western Wadden Sea. A general reduction in disease prevalence in flounder in the entire Dutch Wadden Sea was observed during 1988-2005, which was most likely due to a general improvement in water quality and locally improved habitat conditions for flounder near drainage sluices. Ulcer prevalences outside the two IJsselmeer Lake sluices (Den Oever and Kornwerderzand) declined in this period from approximately 30% to 10% for medium-sized fish. Other skin diseases have also displayed a downward trend at both sites in recent years, with prevalences falling sharply to below 1%. Elsewhere in the Wadden Sea and the Ems-Dollard estuary, disease prevalences have declined towards natural background levels (< 1%). It is concluded that skin diseases, especially ulcers, are useful indicators of environmental quality in the Wadden Sea.

  8. Survey of estrogenic activity in United Kingdom estuarine and coastal waters and its effects on gonadal development of the flounder Platichthys flesus

    SciTech Connect

    Allen, Y.; Scott, A.P.; Matthiessen, P.; Haworth, S.; Thain, J.E.; Feist, S.

    1999-08-01

    Estrogenic discharges are known or suspected to be present in many United Kingdom estuaries and are also occurring from offshore oil and gas installations. The aim of this study was to establish whether estrogens and their mimics are present in marine waters at concentrations that can produce biological responses in fish and, if so, to discover whether the effects are likely to be harmful to populations and communities through changes in reproductive and other physiological processes. Laboratory studies and extensive field surveys were carried out with the euryhaline flounder (Platichthys flesus), using the amount of yolk protein vitellogenin in the blood of free-living male fish as an indicator of exposure to estrogens. Exposure to the synthetic estrogen ethynylestradiol for 3 weeks confirmed that the vitellogenin response was made and showed that this species is about one order of magnitude less sensitive than the freshwater species rainbow trout. The fish did not respond to the estrogen mimic nonylphenol at concentrations of 30 {micro}g/L. Wild male flounder were sampled from four contaminated United Kingdom estuaries: the Tyne, Crouch, Thames, and Mersey. Fish from one or more sites in each estuary had significantly elevated concentrations of vitellogenin in their blood when compared to concentrations in fish from the clean control estuary (Alde River). Vitellogenin concentrations in the Tyne and Mersey fish were four and six orders of magnitude greater, respectively, than control concentrations. Elevated vitellogenin concentrations were also seen in some male flounder caught in coastal areas. Approximately 20% of male fish from the Mersey estuary contained oocytes in their testes, but this intersex condition was not seen elsewhere. The implications of these findings for fish populations are discussed.

  9. Identification of a Tc1-like transposon integration site in the genome of the flounder (Platichthys flesus): a novel use of an inverse PCR method.

    PubMed

    Poćwierz-Kotus, Anita; Burzyński, Artur; Wenne, Roman

    2010-03-01

    The inverse PCR method has been developed and applied employed for the identification of the integration sites of the Tc1-like transposons in the genome of the flounder, Platichthys flesus. One Tc1-like insertion instance was recognized and characterized, demonstrating an efficiency of the method for determining of transposon integration sites. The similarity of the sequence flanking transposon (SFT) to reverse transcriptase sequences (RVT) was demonstrated. It is likely that the insertion took place within currently degenerated LINE (long interspersed nuclear elements) retrotransposon.

  10. Note: the effect of parasite infection on the innate immune response of European flounder (Platichthys flesus L.) in the southern North Sea

    NASA Astrophysics Data System (ADS)

    Skouras, Andreas; Schmidt, Verena; Körting, Wolfgang; Steinhagen, Dieter

    2003-10-01

    In a field study, infecting European flounder (Platichthys flesus L.) subclinically with different parasite species did not result in any alteration of the innate immune response. Due to the high variability in infection status and the immune parameters measured, no relationships of biological significance were found. The data indicate that copepods, as the most abundant parasites, most probably had no major influence on immune responses measured here. Thus it might be concluded that these parameters were not sensitive to parasite infections occurring under natural conditions. The immune parameters considered here are regarded as promising indicators of chemical contaminant-induced variation in piscine immune responses, which could be implemented in pollution monitoring programmes.

  11. Identification of arsenobetaine in sole, lemon sole, flounder, dab, crab and shrimps by field desorption and fast atom bombardment mass spectrometry

    SciTech Connect

    Luten, J.B.; Riekwel-Booy, G.; Greef, M.C.; de Brauw, I.N.

    1983-01-01

    Organo-arsenic has been isolated from sole, lemon sole, flounder, dab, crab and shrimps by extraction or ion-exchange in combination with thin-layer chromatography. An alkaline digestion of the samples, followed by a reduction with sodiumborohydride leads to the formation of trimethylarsine. Field desorption mass spectrometry (FDMS) can be used to identify arsenobetaine in the isolates. Sufficient purification by thin-layer chromatography is found to be a prerequisite for the detection of a protonated molecular ion of arsenobetaine. If this situation is not met acid enchanced FDMS or Fast Atom Bombardment mass spectrometry in high resolution can be used successfully.

  12. Evaluation of cytotoxicity, genotoxicity and embryotoxicity of insecticide propoxur using flounder gill (FG) cells and zebrafish embryos.

    PubMed

    Pandey, Manish Raj; Guo, Huarong

    2014-04-01

    Cytotoxicity, genotoxicity and embryotoxicity of carbamate insecticide propoxur were evaluated using flounder gill (FG) cells and zebrafish embryos. The cytotoxicity of propoxur in FG cells was analyzed by MTT, neutral red uptake (NRU), lactate dehydrogenase (LDH) release and Hoechst 33342 and propidium iodide double staining, and acute cytotoxic effects were observed in a concentration-dependent manner. The 24h-IC50 values of 89.96 ± 1.04, 103.4 ± 1.14 and 86.59 ± 1.13 μg/ml propoxur were obtained by MTT, NRU and LDH assays, respectively. The lethal effects were induced in FG cells mainly through necrosis but not apoptosis as evidenced by double fluorescence staining. Comet assay showed weak genotoxic effects and statistically significant DNA damages were recorded in the cells exposed to highest tested concentration of 75 μg/ml propoxur (p<0.05). Propoxur exerted obvious acute toxic effects on the survival, spontaneous movement, hatching and heart rate, and development (yolk and pericardial sac edema) of zebrafish embryos in both time- and concentration-dependent manner only at ⩾ 100 μg/ml. The corresponding 24h-, 48 h- and 96 h-LC50 values of propoxur in zebrafish embryos were 166.4 ± 1.06, 146.3 ± 1.07 and 134.8 ± 1.06 μg/ml, respectively. The above data obtained suggest a low acute toxicity of propoxur to the in vitro cultured FG cells and zebrafish embryos.

  13. Adaptive divergence in a high gene flow environment: Hsc70 variation in the European flounder (Platichthys flesus L.).

    PubMed

    Hemmer-Hansen, J; Nielsen, E E; Frydenberg, J; Loeschcke, V

    2007-12-01

    Little is known about local adaptations in marine fishes since population genetic surveys in these species have typically not applied genetic markers subject to selection. In this study, we used a candidate gene approach to investigate adaptive population divergence in the European flounder (Platichthys flesus L.) throughout the northeastern Atlantic. We contrasted patterns of genetic variation in a presumably neutral microsatellite baseline to patterns from a heat-shock cognate protein gene, Hsc70. Using two different neutrality tests we found that the microsatellite data set most likely represented a neutral baseline. In contrast, Hsc70 strongly deviated from neutral expectations. Importantly, when estimating standardized levels of population divergence (F(ST)'), we also found a large discrepancy in the patterns of structuring in the two data sets. Thus, samples grouped according to geographical or historical proximity with regards to microsatellites, but according to environmental similarities with regards to Hsc70. The differences between the data sets were particularly pronounced in pairwise comparisons involving populations in the western and central Baltic Sea. For instance, the genetic differentiation between geographically close Baltic Sea and North Sea populations was found to be 0.02 and 0.45 for microsatellites and Hsc70 respectively. Our results strongly suggest adaptive population divergence and indicate local adaptations at the DNA level in a background of high levels of gene flow, typically found in many marine fish species. Furthermore, this study highlights the usefulness of the candidate gene approach for demonstrating local selection in non-model organisms such as most marine fishes.

  14. Developmental changes in melanophores and their asymmetrical responsiveness to melanin-concentrating hormone during metamorphosis in barfin flounder (Verasper moseri).

    PubMed

    Yoshikawa, Naoki; Matsuda, Taihei; Takahashi, Akiyoshi; Tagawa, Masatomo

    2013-12-01

    Barfin flounder larvae exhibit unique black coloration, as well as left-right asymmetry in juvenile stage as in other flatfish. In this study, we first assessed the changes in melanophores with development and then investigated their responsiveness to melanin-concentrating hormone (MCH) during metamorphosis. Larval-type melanophores appeared on both sides of the body before metamorphosis, whereas adult-type melanophores appeared only on the ocular side after metamorphosis. Even in the individuals of this species displaying black coloration, the density of larval-type melanophores was similar to that in transparent larvae of other species. However, unlike in transparent larvae, larval-type melanophores completely dispersed in the black larvae of this species. Therefore, the black coloration during larval stages was mainly due to dispersion, and not the density, of larval-type melanophores. In vitro MCH treatment revealed, for the first time, the responsiveness of melanophores in larval stages. On the ocular side, larval-type melanophores aggregated against MCH during larval stages, while, in the larvae at later metamorphic stages and in juveniles, larval-type melanophores did not aggregate, although aggregation of adult-type melanophores was noted. In contrast, on the blind side, the responsiveness of larval-type melanophores to MCH was consistently present from larval to juvenile stages. The metamorphic transition of MCH responsiveness from larval- to adult-type melanophores only on the ocular side suggests the larval (therefore, immature) nature of the blind side skin. We propose that the inhibited development, and thus the retention of the larval-type skin leads to the formation of the blind side characteristics and is the central mechanism for the flatfish asymmetry.

  15. Spatial and annual variation in fecundity and oocyte atresia of yellowtail flounder, Limanda ferruginea, in U.S. waters

    NASA Astrophysics Data System (ADS)

    McElroy, W. David; Wuenschel, Mark J.; Towle, Emilee K.; McBride, Richard S.

    2016-01-01

    Potential annual fecundity (PAF) was estimated over three years (2010-2012) for yellowtail flounder with individuals from the three stocks off the northeast U.S. coast. Down-regulation of PAF, the resorption of oocytes during development, was evident as the vitellogenic cohort advanced, so we directly measured atresia of vitellogenic oocytes using stereological techniques. PAF models including relative fish condition, stock area, year, and oocyte diameter of the leading cohort explained more variation than models with just size alone based on Akaike information criteria. In a given year, Gulf of Maine females had lower PAF at size than southern New England females. Interannual differences were evident: PAF of both stocks was higher in 2010 and lower in 2012, with 2011 showing less synchronization between these stocks. Differences in size at age and relative condition suggested that energy available for somatic and reproductive growth was lower in some years in the Gulf of Maine and Georges Bank, especially in 2011. Georges Bank PAF and condition were intermediate to the other stocks or more similar to the Gulf of Maine, varying annually. A latitudinal gradient in PAF is evident based on our results and relative to earlier studies that included Canadian stocks. The magnitude of down-regulation was variable across stocks and typically 3-25% of PAF. This can be accounted for in fecundity estimates, by the seasonal schedule of sampling and use of an oocyte diameter term in the fecundity model. Theoretical models of atresia patterns suggested variable rates over the later portion of clutch development. The timing of down-regulation varied among years, and its intensity was influenced by female relative condition. Fecundity was related to fish size, but was also affected by fish condition and oocyte diameter (a proxy for time until spawning), and spatial and temporal effects. A longer time series of PAF may identify environmental drivers that modulate annual stock

  16. Evaluation of cytotoxicity and genotoxicity of insecticide carbaryl to flounder gill cells and its teratogenicity to zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Pandey, Manish Raj; Guo, Huarong

    2015-04-01

    In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill (FG) cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking (NRU), lactate dehydrogenase (LDH) releasing and Hoechst 33342 and propidium idodide (PI) double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24 h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mg L-1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining demonstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl (20 mg L-1, P > 0.05) as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations ≥10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24 h-, 48 h- and 96 h-LC50 values of carbaryl to zebrafish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that carbaryl is moderately toxic to FG cells cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24 h-IC50 and LC50 indicated.

  17. Inferences from the horizontal distribution of dab Limanda limanda (L.) and flounder Platichthys flesus (L.) larvae in the southeastern North Sea

    NASA Astrophysics Data System (ADS)

    Campos, Wilfredo L.; Kloppmann, Matthias; von Westernhagen, Hein

    The horizontal distribution of dab, Limanda limanda L., and flounder, Platichthys flesus L., larvae in the southeastern North Sea was studied during the winter-spring period of 1992. Dab larvae comprised 51% of all fish larvae recorded and increased in abundance from February to late April, with a mean overall larval density of 38.8 ind·m -2 during the study period. Flounder larvae comprised 10% of all fish larvae and were most abundant in late March with an average density of 12.5 ind·m -2. Highest larval concentrations for both species were observed in waters off the west Frisian coast and in the inner German Bight, consistent with previously reported egg concentrations. Correlation analyses indicated similar distributions of early (I & II) stage larvae, but dissimilar distribution patterns in later (III & IV) larval stages. This is consistent with known spawning locations and postlarval habitats for the two species. Vertical migration is proposed as a potential mechanism that may explain the observed stage-specific horizontal distributions. Apparent differences in relative growth between two high-density centres suggested that larval dynamics may be different in these areas.

  18. Morphology, ultrastructure, genetics, and morphometrics of Diplostomum sp. (Digenea: Diplostomidae) metacercariae infecting the European flounder, Platichthys flesus (L.) (Teleostei: Pleuronectidae), off the northwest coast of Portugal.

    PubMed

    Cavaleiro, Francisca I; Pina, Susana; Russell-Pinto, Fernanda; Rodrigues, Pedro; Formigo, Nuno E; Gibson, David I; Santos, Maria J

    2012-01-01

    The morphology, ultrastructure, genetics, and morphometrics of a species of Diplostomum von Nordmann 1832 (Digenea: Diplostomidae), isolated from the European flounder (Platichthys flesus (L.)) caught off the northwest coast of Portugal, are characterized. The metacercarial stage was found unencysted in the lens capsule of the eye. Light microscopical observations revealed the existence of some variability in specimen shape and size, with two morphotypes, referred to as "round" and "long", being apparent. Scanning electron microscopy revealed a smooth, unarmed tegument, with the lappet region being the most irregular and porose. Both the oral and ventral suckers were provided with a series of papillae, which presented very distinctive ultrastructural features and were particularly conspicuous in the case of the ventral sucker. The two morphotypes detected were found to have 100% genetic correspondence in the 18S + ITS1 + 5.8S region of the rDNA. Since the genetic data for this metacercaria differed from those of the species of Diplostomum available in GenBank, a description of a new genotype (accession number GQ370809) is provided. The molecular phylogenetic analyses, in conjunction with principal components and cluster analyses based on morphometric data, revealed the existence of consistent differences between the Diplostomum sp. metacercariae from flounder compared with Diplostomum spathaceum, Diplostomum mergi, Diplostomum pseudospathaceum, and Diplostomum paracaudum. The latter of these species was found to be the most similar to the present material. Our results do not support an evolutionary separation of the European and North American species of Diplostomum.

  19. Interrelation between melanocyte-stimulating hormone and melanin-concentrating hormone in physiological body color change: roles emerging from barfin flounder Verasper moseri.

    PubMed

    Mizusawa, Kanta; Kobayashi, Yuki; Yamanome, Takeshi; Saito, Yumiko; Takahashi, Akiyoshi

    2013-01-15

    In teleosts, as their names suggest, the main target cells of melanocyte-stimulating hormone (MSH) and melanin-concentrating hormone (MCH) are the chromatophores in the skin, where these peptide hormones play opposing roles in regulating pigment migration. These effects are obvious especially when their activities are examined in vitro. On the contrary, while MCH also exhibits activity in vivo, MSH does not always stimulate pigment dispersion in vivo because of predominant sympathetic nervous system. A series of our investigations indicates that this is also the case in barfin flounder, Verasper moseri. Interestingly, we observed that mch expression and the tissue contents of MCH can be easily influenced by changes in environmental color conditions, while gene expression and tissue contents related to MSH scarcely respond to color changes. Transcripts of MSH and MCH receptor genes have been identified in a variety of tissues of this fish species, suggesting that these are multifunctional peptide hormones. Nevertheless, chromatophores in the skin still offer important clues in the efforts to elucidate the functions of melanotropic peptides. Herein, we review the most recent advancements of our studies on MSH and MCH and their receptors in the barfin flounder and discuss the interrelations between these peptides, focusing on their roles in influencing pigment migration in the skin.

  20. Dietary vitamin A, ascorbic acid and α-tocopherol affect the gonad development and reproductive performance of starry flounder Platichthys stellatus broodstock

    NASA Astrophysics Data System (ADS)

    Wang, Jiying; Li, Baoshan; Liu, Xudong; Ma, Jingjing; Wang, Shixin; Zhang, Limin

    2014-03-01

    The present trial was conducted with starry flounder Platichthys stellatus broodstock to evaluate the effects of dietary vitamin A, ascorbic acid, and α-tocopherol on the gonadal development and reproductive performance. 8 000 IU/kg diet vitamin A (VA group), 500 mg/kg diet ascorbic acid (Vcpp group), or 250 mg/kg diet α-tocopherol (α-TA group) was added into basal diet to create 3 vitamin experimental diets, respectively. Each diet was fed to 450 starry flounder broodstock for 104 days. Samples were collected weekly. The gonadosomatic index (GSI) of 3 vitamin experimental groups first decreased and then increased. Maximum GSI of Vcpp group was higher than that of α-TA group but lower than that of VA group. The spawning periods of 3 vitamin experimental groups lasted 49, 56, and 45 days, respectively. No mature eggs were observed in the control group during the trial. The absolute fecundity (AF) and relative fecundity (RF) of α-TA group was higher than that of Vcpp group but lower than that of VA group. The results suggest that different vitamins play different roles in the fish reproductive process. Vitamin A stimulated the maturation of the ovary, ascorbic acid prolonged the spawning period, and α-tocopherol affected the development of the eggs.

  1. Isolation and characterization of a rhabdovirus from starry flounder (Platichthys stellatus) collected from the northern portion of Puget Sound, Washington, USA

    USGS Publications Warehouse

    Mork, Christina; Hershberger, Paul K.; Kocan, Richard; Batts, William N.; Winton, James R.

    2004-01-01

    The initial characterization of a rhabdovirus isolated from a single, asymptomatic starry flounder (Platichthys stellatus) collected during a viral survey of marine fishes from the northern portion of Puget Sound, Washington, USA, is reported. Virions were bullet-shaped and approximately 100 nm long and 50 nm wide, contained a lipid envelope, remained stable for at least 14 days at temperatures ranging from -80 to 5 degrees C and grew optimally at 15 degrees C in cultures of epithelioma papulosum cyprini (EPC) cells. The cytopathic effect on EPC cell monolayers was characterized by raised foci containing rounded masses of cells. Pyknotic and dark-staining nuclei that also showed signs of karyorrhexis were observed following haematoxylin and eosin, May-Grunwald Giemsa and acridine orange staining. PAGE of the structural proteins and PCR assays using primers specific for other known fish rhabdoviruses, including Infectious hematopoietic necrosis virus, Viral hemorrhagic septicemia virus, Spring viremia of carp virus, and Hirame rhabdovirus, indicated that the new virus, tentatively termed starry flounder rhabdovirus (SFRV), was previously undescribed in marine fishes from this region. In addition, sequence analysis of 2678 nt of the amino portion of the viral polymerase gene indicated that SFRV was genetically distinct from other members of the family Rhabdoviridae for which sequence data are available. Detection of this virus during a limited viral survey of wild fishes emphasizes the void of knowledge regarding the diversity of viruses that naturally infect marine fish species in the North Pacific Ocean.

  2. Protective efficacy and immune responses induced by a DNA vaccine encoding codon-optimized PPA1 against Photobacterium damselae subsp. piscicida in Japanese flounder.

    PubMed

    Kato, Goshi; Yamashita, Kozue; Kondo, Hidehiro; Hirono, Ikuo

    2015-02-18

    Photobacterium damselae subsp. piscicida (Pdp) kills many cultured marine fish. As it evolves resistance to existing vaccines, new vaccines are needed. PPA1 is a major antigenic protein of Pdp. Here, DNA vaccines encoding wild-type PPA1 (pPPA1(wt)) and codon-optimized PPA1 (pPPA1(opt)) were constructed and tested against Pdp in Japanese flounder. The mRNA levels of the two antigenic genes at the vaccination site were not different, but the protein level was significantly higher in the pPPA1(opt)-vaccinated fish. In addition, after a bacterial challenge, the levels of interleukin (IL)-1β, IL-6 and IFN-γ mRNA significantly increased in the pPPA1(opt)-vaccinated fish but not in the pPPA1(wt)-vaccinated fish. The relative percent survival (RPS) after the challenge was higher in the pPPA1(opt)-vaccinated fish (90.9) than in the pPPA1(wt)-vaccinated fish (69.2). At the early stage of the infection after the challenge, the number of viable Pdp in the spleen was significantly lower in the pPPA1(opt)-vaccinated fish than in the pPPA1(wt)-vaccinated fish. These data show that codon-optimized DNA vaccine pPPA1(opt) had a strong immunogenicity and conferred protective efficacy against Pdp infection in Japanese flounder.

  3. Analysis of nodularin-R in eider (Somateria mollissima), roach (Rutilus rutilus L.), and flounder (Platichthys flesus L.) liver and muscle samples from the western Gulf of Finland, northern Baltic Sea.

    PubMed

    Sipiä, Vesa O; Sjövall, Olli; Valtonen, Terhi; Barnaby, Deborah L; Codd, Geoffrey A; Metcalf, James S; Kilpi, Mikael; Mustonen, Olli; Meriluoto, Jussi A O

    2006-11-01

    Nodularin (NODLN) is a cyanobacterial hepatotoxin that may cause toxic effects at very low exposure levels. The NODLN-producing cyanobacterium Nodularia spumigena forms massive blooms in the northern Baltic Sea, especially during the summer. We analyzed liver and muscle (edible meat) samples from common eider (Somateria mollissima), roach (Rutilus rutilus L.), and flounder (Platichthys flesus L.) for NODLN-R by liquid chromatography/mass spectrometry (LC-MS) and enzyme-linked immunosorbent assay (ELISA). Thirty eiders, 11 roach, and 15 flounders were caught from the western Gulf of Finland between September 2002 and October 2004. Eiders from April to June 2003 were found dead. The majority of samples were analyzed by LC-MS and ELISA from the same sample extracts (water:methanol:n-butanol, 75:20:5, v:v:v). Nodularin was detected in 27 eiders, nine roach, and eight flounders. Eider liver samples contained NODLN up to approximately 200 microg/kg dry weight and muscle samples at approximately 20 microg/kg dry weight, roach liver samples 20 to 900 microg NODLN/kg dry weight and muscle samples 2 to 200 microg NODLN/kg dry weight, and flounder liver samples approximately 5 to 1,100 microg NODLN/kg dry weight and muscle samples up to 100 microg NODLN/kg dry weight. The NODLN concentrations found in individual muscle samples of flounders, eiders, and roach (1-200 microg NODLN/kg dry wt) indicate that screening and risk assessment of NODLN in Baltic Sea edible fish and wildlife are required for the protection of consumer's health.

  4. Seasonal patterns of winter flounder Pseudopleuronectes americanus abundance and reproductive condition on the New York Bight continental shelf.

    PubMed

    Wuenschel, M J; Able, K W; Byrne, D

    2009-05-01

    To resolve varied and sometimes conflicting accounts of spawning and habitat characteristics for winter flounder Pseudopleuronectes americanus, seasonal patterns in abundance and reproductive condition were investigated in the New York Bight, near the southern edge of their current reproductive range. Fish were collected from trawl surveys on the inner continental shelf from October 2006 to October 2007. Pseudopleuronectes americanus were most abundant during January and April surveys, were rarely collected in August, with intermediate abundances in June and October. Measurements of fish condition [hepato-somatic index (I(H)), condition factor (K) and the per cent dry mass of muscle tissue (%M(D))] and reproductive condition [gonado-somatic index (I(G))] were determined to evaluate seasonal changes in energy accumulation and depletion and reproduction. Males and females had similar patterns in body and reproductive condition, although the magnitude of change was greater for females. I(H) values were highest during spring and early summer, suggesting increased feeding following spawning. K and %M(D) increased through spring and summer then declined in the autumn and winter concurrent with gonadal development. Gonads began developing in the autumn, and in January, I(G) values approached spawning levels, with many spent individuals collected in spring. Within these general patterns, however, there was a large degree of variability among individuals, and a few mature non-reproductive ('skipped spawning') females were observed. In the period after spawning, increased energy intake, indicated by increased I(H), may influence reproductive output since this energy is gradually transferred to the muscle and used for gonadal development in the forthcoming year. The occurrence of ripening individuals on the inner continental shelf in January suggests that these fish either rapidly move into estuaries to spawn by February-March or they remain on the inner shelf to spawn, or

  5. Insulin-like growth factors I and II in starry flounder (Platichthys stellatus): molecular cloning and differential expression during embryonic development.

    PubMed

    Xu, Yongjiang; Zang, Kun; Liu, Xuezhou; Shi, Bao; Li, Cunyu; Shi, Xueying

    2015-02-01

    In order to elucidate the possible roles of insulin-like growth factors I and II (IGF-I and IGF-II) in the embryonic development of Platichthys stellatus, their cDNAs were isolated and their spatial expression pattern in adult organs and temporal expression pattern throughout embryonic development were examined by quantitative real-time PCR assay. The IGF-I cDNA sequence was 1,268 bp in length and contained an open reading frame (ORF) of 558 bp, which encoded 185 amino acid residues. With respect to IGF-II, the full-length cDNA was 899 bp in length and contained a 648-bp ORF, which encoded 215 amino acid residues. The amino acid sequences of IGF-I and IGF-II exhibited high identities with their fish counterparts. The highest IGF-I mRNA level was found in the liver for both sexes, whereas the IGF-II gene was most abundantly expressed in female liver and male liver, gill, and brain. The sex-specific and spatial expression patterns of IGF-I and IGF-II mRNAs are thought to be related to the sexually dimorphic growth and development of starry flounder. Both IGF-I and IGF-II mRNAs were detected in unfertilized eggs, which indicated that IGF-I and IGF-II were parentally transmitted. Nineteen embryonic development stages were tested. IGF-I mRNA level remained high from unfertilized eggs to low blastula followed by a significant decrease at early gastrula and then maintained a lower level. In contrast, IGF-II mRNA level was low from unfertilized eggs to high blastula and peaked at low blastula followed by a gradual decrease. Moreover, higher levels of IGF-I mRNA than that of IGF-II were found from unfertilized eggs to high blastula, vice versa from low blastula to newly hatched larva, and the different expression pattern verified the differential roles of IGF-I and IGF-II in starry flounder embryonic development. These results could help in understanding the endocrine mechanism involved in the early development and growth of starry flounder.

  6. Hepatic ethoxyresorufin O-deethylase (EROD) activity in flounder (Platichthys flesus) from contaminant impacted estuaries of the United Kingdom: continued monitoring 1999-2001.

    PubMed

    Kirby, M F; Neall, P; Bateman, T A; Thain, J E

    2004-07-01

    The determination of hepatic ethoxyresorufin O-deethylase (EROD) has been used to assess the induction of the mixed function oxygenase system (MFO) of flounder (Platichthys flesus) in UK estuaries. Induction of the MFO system denotes possible exposure to certain organic contaminants (e.g. polycyclic aromatic hydrocarbons, polychlorinated biphenyls) and its measure has been incorporated in national monitoring programmes. This study presents EROD monitoring data from 5 UK estuaries taken between 1999 and 2001 and builds on data from previous years. The results reveal that for all sampled estuaries EROD values have been significantly (p < 0.05) elevated on the majority of occasions in comparison with the reference estuary, the Alde in Suffolk, UK. However, the limited temporal scale of the reported monitoring does not allow any conclusions to be drawn with respect to trends in the data. Possible factors influencing the data (size, gender, seasonality, reproductive status, etc.) are discussed and recommendations for continued monitoring are made.

  7. Ethoxyresorufin O-deethylase (EROD) activity in the liver of dab (Limanda limanda L.) and flounder (Platichthys flesus L.) from the German Bight. EROD expression and tissue contamination

    NASA Astrophysics Data System (ADS)

    Westernhagen, H. v.; Krüner, G.; Broeg, K.

    1999-12-01

    Ethoxyresorufin O-deethylase (EROD) activity was measured in the liver of dab (Limanda limanda) and flounder (Platichthys flesus) from the German Bight (southern North Sea) and compared with muscle and liver polychlorinated biphenyl (PCB) concentrations in an attempt to relate EROD activity to PCB body burden. In none of the different datasets (species-, tissue- or matrix-dependent) was a significant (P<0.05) correlation between PCB tissue contamination and EROD activity found. Yet EROD activity was significantly correlated with polycyclic aromatic hydrocarbons (PAH) levels (phenanthrene, fluoranthene, pyrene) in muscle tissue, indicating a possible dependence of EROD expression on other ubiquitous organic contaminants, thus making it a suitable biomarker for general pollution.

  8. Metabolic responses to hypoxia of Lycenchelys verrillii (wolf eelpout) and Glyptocephalus cynoglossus (witch flounder): Sedentary bottom fishes of the Hatteras/Virginia middle slope

    USGS Publications Warehouse

    Moser, M.L.; Ross, S.W.; Sulak, K.J.

    1996-01-01

    We collected wolf eelpouts Lycenchelys verrillii and witch flounder Glyptocephalus cynoglossus from Hatteras (North Carolina, USA) and Virginia (USA) Middle Slope sites using a submersible, and made shipboard measurements of their respiration rates and survival in hypoxic (<10% O2 saturation) and anoxic conditions. Both species from the Hatteras site reduced their respiration rates as ambient oxygen decreased, but eelpouts from the Virginia site maintained a constant respiration rate until oxygen saturation dropped below 20%. Moreover, eelpouts from the Hatteras site were significantly more tolerant of hypoxic conditions than fish from the Virginia site and survived anoxia for short periods. These results and our submersible observations of fish behavior support the hypothesis that the Hatteras Middle Slope fauna is exposed to short-term hypoxia events.

  9. Sequence analysis and expression of the M1 and M2 matrix protein genes of hirame rhabdovirus (HIRRV)

    USGS Publications Warehouse

    Nishizawa, T.; Kurath, G.; Winton, J.R.

    1997-01-01

    We have cloned and sequenced a 2318 nucleotide region of the genomic RNA of hirame rhabdovirus (HIRRV), an important viral pathogen of Japanese flounder Paralichthys olivaceus. This region comprises approximately two-thirds of the 3' end of the nucleocapsid protein (N) gene and the complete matrix protein (M1 and M2) genes with the associated intergenic regions. The partial N gene sequence was 812 nucleotides in length with an open reading frame (ORF) that encoded the carboxyl-terminal 250 amino acids of the N protein. The M1 and M2 genes were 771 and 700 nucleotides in length, respectively, with ORFs encoding proteins of 227 and 193 amino acids. The M1 gene sequence contained an additional small ORF that could encode a highly basic, arginine-rich protein of 25 amino acids. Comparisons of the N, M1, and M2 gene sequences of HIRRV with the corresponding sequences of the fish rhabdoviruses, infectious hematopoietic necrosis virus (IHNV) or viral hemorrhagic septicemia virus (VHSV) indicated that HIRRV was more closely related to IHNV than to VHSV, but was clearly distinct from either. The putative consensus gene termination sequence for IHNV and VHSV, AGAYAG(A)(7), was present in the N-M1, M1-M2, and M2-G intergenic regions of HIRRV as were the putative transcription initiation sequences YGGCAC and AACA. An Escherichia coli expression system was used to produce recombinant proteins from the M1 and M2 genes of HIRRV. These were the same size as the authentic M1 and M2 proteins and reacted with anti-HIRRV rabbit serum in western blots. These reagents can be used for further study of the fish immune response and to test novel control methods.

  10. Mucus pH of the tiger puffer Takifugu rubripes is an important factor for host identification by the monogenean Heterobothrium okamotoi.

    PubMed

    Hirazawa, N; Oshima, S; Mitsuboshi, T; Yamashita, S

    2003-09-01

    We examined a host-finding factor of the monogenean Heterobothrium okamotoi oncomiracidia to develop an alternative prophylaxis. H. okamotoi oncomiracidia attached preferentially to gill filaments and skin mucus from the tiger puffer Takifugu rubripes compared with corresponding material from other tested fishes (amber jack Seriola dumerili, red sea bream Pagrus major, Japanese flounder Paralichthys olivaceus and spotted halibut Verasper variegatus). The body mucus pH of the tiger puffer was 6.40 +/- 0.09 (mean +/- S.D.), whereas that for the other tested fishes was 7.2-7.4. To find if this difference in pH could account for the specific targeting of tiger puffer by H. okamotoi oncomiracidia, the attachment response of the oncomiracidia to pieces of agar buffered at various pH between 6.0 and 7.4 was examined. The number of attaching oncomiracidia was maximal at pH 6.4. We produced gynogenetic tiger puffers from a single female. These gynogenetic individuals showed a variety of body mucus pH and they were exposed to the oncomiracidia. Thirteen days after exposure, more young H. okamotoi were found on the gills of gynogenetic tiger puffer with mucus at pH 6.3-6.6, than on gills of fish with mucus at pH 6.0-6.3 and 6.6-7.2. H. okamotoi exploits the body mucus pH to identify the host. The simplicity of pH as a lure may lead to development of a simple and economical method to control H. okamotoi outbreaks.

  11. Generation and characterization of NV gene-knockout recombinant viral hemorrhagic septicemia virus (VHSV) genotype IVa.

    PubMed

    Kim, Min Sun; Kim, Dong Soo; Kim, Ki Hong

    2011-11-03

    A recombinant viral hemorrhagic septicemia virus (rVHSV-deltaNV-EGFP) containing the enhanced green fluorescent protein (EGFP) gene instead of the NV gene was produced using the reverse-genetics method. For use as a positive control, another recombinant virus (rVHSV-wild) was also generated, which had an identical nucleotide sequence to the wild-type VHSV genome except for a few artificially replaced nucleotides. The rVHSVs were rescued using a system controlled by T7 RNA polymerase supplied by a retroviral vector. Generation of rVHSV-deltaNV-EGFP and rVHSV-wild was confirmed by sequencing of RT-PCR products, and rescue of infectious rVHSVs was confirmed by observation of plaque formation. Replication efficiency of rVHSV-wild was distinctly lower than that of wild-type VHSV, suggesting that the artificially replaced nucleotides, especially when immediately preceding the G or NV gene start codons, might affect the replication of the virus. Replication of rVHSV-deltaNV-EGFP was slightly lower than that of rVHSV-wild when epithelioma papulosum cyprini cells were infected with multiplicity of infection (MOI) 1.0, but much lower when cells were infected with MOI 0.00001. These results suggest that the NV gene plays an important role in VHSV replication through interactions with host-cell responses, and the lower replication ability of rVHSV-wild compared to wild-type VHSV might be caused by replaced nucleotides just before the NV gene open reading frame (ORF) rather than the G gene ORF. In olive flounder Paralichthys olivaceus, rVHSV-wild produced slower-progressing mortalities than wild-type VHSV, whereas rVHSV-deltaNV-EGFP pathogenesis was highly attenuated. These results suggest that the NV protein of VHSV may play an important role not only in viral replication but also in viral pathogenesis.

  12. Streptococcus hongkongensis sp. nov., isolated from a patient with an infected puncture wound and from a marine flatfish.

    PubMed

    Lau, Susanna K P; Curreem, Shirly O T; Lin, Cherry C N; Fung, Ami M Y; Yuen, Kwok-Yung; Woo, Patrick C Y

    2013-07-01

    A bacterium, HKU30(T), was isolated from the infected tissue of a patient with wound infection after puncture by a fish fin. Cells are facultative anaerobic, non-spore-forming, non-motile, Gram-positive cocci arranged in chains. Colonies were non-haemolytic. The strain was catalase, oxidase, urease and Voges-Proskauer test negative. It reacted with Lancefield's group G antisera and was resistant to optochin. It grew on bile aesculin agar and in 5 % NaCl. It was unidentified by three commercial identification systems. 16S rRNA gene sequence analysis indicated that the bacterium shared 98.2, 97.7, 97.4 and 97.1 % nucleotide identities with Streptococcus iniae, Streptococcus pseudoporcinus, Streptococcus parauberis and Streptococcus uberis, respectively. The DNA G+C content was 35.6 ± 0.9 mol% (mean ± sd). In view of the occupational exposure of the patient, an epidemiological study was performed to isolate the bacterium from marine fish. Two strains, with similar phenotypic and genotypic characteristics to those of HKU30(T), were isolated from a three-lined tongue sole (Cynoglossus abbreviatus) and an olive flounder (Paralichthys olivaceus) respectively. Phylogenetic analysis of four additional housekeeping genes, groEL, gyrB, sodA and rpoB, showed that the three isolates formed a distinct branch among known species of the genus Streptococcus, being most closely related to S. parauberis (CCUG 39954(T)). DNA-DNA hybridization demonstrated ≤ 53.8 % DNA relatedness between the three isolates and related species of the genus Streptococcus. A novel species, Streptococcus hongkongensis sp. nov., is proposed. The type strain is HKU30(T) ( = DSM 26014(T) = CECT 8154(T)).

  13. Molecular characterization and quantification of estrogen receptors in turbot (Scophthalmus maximus).

    PubMed

    Hu, Peng; Meng, Zhen; Jia, Yudong

    2017-01-10

    Estrogens regulate various reproductive processes via estrogen receptor (ER)-mediated signaling pathway in vertebrates. In this study, full-length sequences coding for ERα, ERβ1 and ERβ2 were isolated from female turbot (Scophthalmus maximus) by homology cloning and a strategy based on rapid amplification of cDNA end-polymerase chain reaction (RACE-PCR). The nucleotide and amino acid sequences of turbot ERs showed high homologies with the corresponding sequences of other fish species and significant homology with the Japanese flounder (Paralichthys olivaceus) and the European sea bass (Dicentrarchus labrax). Turbot ERs contained six typical nuclear receptor-characteristic domains and exhibited high evolutionary conservation in the functional domains. Quantitative real-time polymerase chain reaction analysis revealed that the erα and erβ (β1, β2) mRNAs were abundant in the liver and ovary, respectively. Furthermore, hepatic mRNA levels of erα and vitellogenin (vtg) were found increased gradually from pre-vitellogenesis to late-vitellogenesis stages, with the highest values observed at the late-vitellogenesis stage, and then decreased from migratory-nucleus to atresia stages. However, mRNA levels of erα in the ovary remained unchanged during ovarian development. Hepatosomatic index, gonadosomatic index, serum estradiol-17β and the mRNA levels of erβ1 and erβ2 in the ovary manifested results similar to the expression of erα mRNAs in the liver. These findings indicated that ERα is mainly involved in hepatic vitellogenesis, and ERβs may play crucial roles to regulate ovarian development in turbot. Overall, this study improves understanding of the physiological functions of turbot ERs, which will be valuable for fish reproduction and broodstock management.

  14. Molecular characterization and expression of urotensin II and its receptor in the flounder (Platichthys flesus): a hormone system supporting body fluid homeostasis in euryhaline fish.

    PubMed

    Lu, Weiqun; Greenwood, Michael; Dow, Louise; Yuill, Janette; Worthington, Jonathan; Brierley, Matthew J; McCrohan, Catherine R; Riccardi, Daniela; Balment, Richard J

    2006-08-01

    Urotensin II (UII) is a potent vasoconstrictor in mammals, but the source of circulating UII remains unclear. Investigations of the caudal neurosecretory system (CNSS), considered the major source of UII in fish, alongside target tissue expression of UII receptor (UT), can provide valuable insights into this highly conserved regulatory system. We report UII gene characterization, expression of the first fish UT, and responses to salinity challenge in flounder. The 12-aa UII peptide shares 73% sequence identity with pig and human UII. Flounder UT receptor shares 56.7% identity with rat. Although the CNSS is the major site of UII expression, RT-PCR revealed expression of UII and UT in all tissues tested. Around 30-40% of large CNSS Dahlgren cells expressed UII, alone or in combination with urotensin I and/or corticotrophin releasing hormone. Immunolocalization of UT in osmoregulatory tissues (gill, kidney) was associated with vascular elements. There were no consistent differences in CNSS UII expression or plasma UII between seawater (SW)- and freshwater (FW)-adapted fish, although gill and kidney UT expression was lower in FW animals. After acute transfer from SW to FW, plasma UII and kidney and gill UT expression were reduced, whereas UT expression in kidney was increased after reverse transfer. UII appears to be more important to combat dehydration and salt-loading in SW than the hemodilution faced in FW. Potentially, altered target tissue sensitivity through changes in UT expression, is an important physiological controlling mechanism, not only relevant for migratory fish but also likely conserved in mammals.

  15. The activity of macrophage aggregates in the liver of flounder (Platichthys flesus) and wrasse (Symphodus melops) is associated with tissue damage.

    PubMed

    Broeg, Katja

    2010-01-01

    The phagocytic activity of macrophage aggregates (MAs) in the liver of fish is characterized by high acid phosphatase activity and generation of reactive oxygen species (ROS). Question of the present study was whether these activities were associated with damage of adjacent and surrounding liver cells and the macrophages itself. Thus, the lysosomal membrane stabilities (LMS) of two different populations of lysosomes (LMS1, short destabilization periods, and LMS2, longer destabilization periods) of liver cells close to MAs of different phagocytic activity were measured as indicator for cellular integrity by computer assisted image analysis. They were then compared to the LMS of hepatocytes remote from any MA. In addition, LMS was also assessed inside the MAs. Studies were performed on adult European flounder (Platichthys flesus) and corkwing wrasse (Symphodus melops) caught at clean and polyaromatic hydrocarbon (PAH)-contaminated field locations of the German Bight and the Karmoy peninsula at the West coast of Norway. In the hepatocytes adjacent to MAs which showed medium to high phagocytic activity, LMS was significantly decreased with a reduction of both, first (LMS1), and second (LMS2) destabilization periods in both species. LMS1 inside of these MAs was extremely low, whereas LMS2 was sometimes even higher compared to the liver cells. We suggest that LMS1 represents phagosomes which had contact to ROS and LMS2 represents less affected primary lysosomes. In single flounder and wrasse with liver tumors, MAs in the vicinity of these tumors showed low phagocytic activity and were not associated with adverse effects on adjacent tumor cells. Inside these MAs, LMS1 was higher compared to MAs with high phagocytic activity in wrasse from the reference site, indicating that cytotoxicity was not involved in their phagocytic deficiency.

  16. Carcinogenicity of Black Rock Harbor sediment to the eastern oyster and trophic transfer of Black Rock Harbor carcinogens from the blue mussel to the winter flounder

    SciTech Connect

    Gardner, G.R.; Yevich, P.P.; Malcolm, A.R. ); Harshbarger, J.C. )

    1991-01-01

    The eastern oyster (Crassostrea virginica) developed neoplastic disorders when experimentally exposed both in the laboratory and field to chemically contaminated sediment from Black Rock Harbor (BRH), Bridgeport, Connecticut. Neoplasia was observed in oysters after 30 or 60 days of continuous exposure in a laboratory flow-through system to a 20 mg/L suspension of BRH sediment plus postexposure periods of 3, 30, or 60 days. Composite tumor incidence was 13.6% for both exposures. Tumor occurrence was highest in the renal excretory epithelium, followed in order by gill, gonad, gastrointestinal, heart, and embryonic neural tissue. Regression of experimental neoplasia was not observed when the stimulus was discontinued. In field experiments, gill neoplasms developed in oysters, deployed in cages for 30 days at BRH and 36 days at a BRH dredge material disposal area in Central Long Island Sound, and kidney and gastrointestinal neoplasms developed in caged oysters deployed 40 days in Quincy Bay, Boston Harbor. Oysters exposed to BRH sediment in the laboratory and in the field accumulated high concentrations of polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), and chlorinated pesticides. Chemical analyses demonstrated high concentrations of PCBs, PAHs, chlorinated pesticides, and heavy metals in BRH sediment. Known genotoxic carcinogens, cocarcinogens, and tumor promoters were present as contaminants. The uptake of parent PAH and PCBs from BRH sediment observed in oysters also occurs in blue mussels (Mytilus edulis). Winter flounder fed BRH-contaminated blue mussels contained xenobiotic chemicals analyzed in mussels. The flounder developed renal and pancreatic neoplasms and hepatotoxic neoplastic precursor lesions, demonstrating trophic transfer of sediment-bound carcinogens up the food chain.

  17. Functional analysis of a metal response element in the regulatory region of flounder cytochrome P450 1A and implications for environmental monitoring of pollutants.

    PubMed

    Lewis, Nick A; Williams, Tim D; Chipman, James K

    2006-08-01

    Cytochrome P450 1A (CYP 1A) is a member of a multigene family of xenobiotic metabolizing enzymes. CYP 1A is highly inducible by numerous environmental contaminants including polycyclic aromatic hydrocarbons (PAHs) and is widely used in biomonitoring studies. Therefore, understanding the regulation of this gene is important for accurate interpretation of biomarker data. We describe here the functional role of a metal response element (MRE) in the European flounder CYP 1A promoter region. To help elucidate the potential role of this MRE, reporter gene constructs, with or without site-directed mutagenesis, were used in conjunction with a dual-luciferase assay. The electrophoretic mobility shift assay (EMSA) was also used to investigate potential protein binding at this MRE site. Treatment with the prototypical PAH 3-methylcholanthrene (3MC) (1.0 microM) produced a dose-dependent response at the CYP 1A promoter, whereas treatment with cadmium (0-1.0 microM) produced little transcriptional activity at either the wild-type or mutated promoter. Cotreatment with cadmium (1.0 microM) and 3MC (1.0 microM) reduced induction at this promoter to 1.83-fold compared to 3MC treatment alone (4.0-fold induction). Mutation of the MRE site resulted in abolishment of this cadmium-related loss of 3MC-dependent activity. Furthermore, a retarded band was observed in the EMSA when the MRE was used as a probe and incubated with liver nuclear protein from flounder treated with cadmium. The results not only add to knowledge of the diversity in vertebrate CYP 1A regulation but also raise the complexity of interpretation of CYP 1A induction in monitoring studies that involve mixtures of PAHs and metals.

  18. Risk of environmental genotoxicity in the Baltic Sea over the period of 2009-2011 assessed by micronuclei frequencies in blood erythrocytes of flounder (Platichthys flesus), herring (Clupea harengus) and eelpout (Zoarces viviparus).

    PubMed

    Baršienė, Janina; Rybakovas, Aleksandras; Lang, Thomas; Grygiel, Wlodzimierz; Andreikėnaitė, Laura; Michailovas, Aleksandras

    2012-06-01

    Environmental genotoxicity was investigated at 82 locations encompassing different regions of the Baltic Sea. Micronuclei (MN) analysis was performed in erythrocytes of 1892 specimens of flounder Platichthys flesus, herring Clupea harengus and eelpout Zoarces viviparus, three of the most common native fish species of the Baltic Sea collected in 2009-2011. MN background levels in fish were determined using data obtained in 2001-2011 from 107 Baltic sites. Extremely high genotoxicity risk zones were found for flounder at 11 stations out of 16 in 2009 and 33 stations of 41 in 2010-2011, for herring, at 5 of 18 stations in 2009 and 20 of 43 stations in 2010-2011, in eelpout only at one out of 29 stations. The sampling stations were restricted mainly to the southern and eastern Baltic Sea offshore zones and in most of them, MN frequencies in flounder and herring significantly exceeded the reference and background levels of micronuclei. This is a first attempt to evaluate the background MN responses, as well as low, high and extremely high genotoxicity risk levels for native fish species.

  19. Possible paracrine function of alpha-melanocyte-stimulating hormone and inhibition of its melanin-dispersing activity by N-terminal acetylation in the skin of the barfin flounder, Verasper moseri.

    PubMed

    Kobayashi, Yuki; Mizusawa, Kanta; Yamanome, Takeshi; Chiba, Hiroaki; Takahashi, Akiyoshi

    2009-05-01

    Melanocyte-stimulating hormone (MSH) is generated from a precursor protein, proopiomelanocortin (POMC), mainly in the pituitary. The barfin flounder, Verasper moseri, expresses three different POMC genes (Pomc), among which Pomc-c is also expressed in the skin. Herein, we characterized the biological significance of POMC and MSH produced in barfin flounder skin. The reverse transcription polymerase chain reaction showed the expression of Pomc-c in isolated non-chromatophoric dermal cells. Mass spectrometry analyses of fractions of skin extract separated by high-performance liquid chromatography revealed the presence of a peptide with a molecular mass corresponding to Des-acetyl (Ac)-alpha-MSH-C derived from POMC-C. These results indicate that, in addition to endocrine functions, MSH in barfin flounder is associated with skin pigmentation via paracrine mechanisms. On the other hand, in vitro studies showed that Des-Ac-alpha-MSH-C dispersed pigments in both melanophores and xanthophores. These functions are similar to those of Des-Ac-alpha-MSH, which differs from Des-Ac-alpha-MSH-C only at the C-terminus, generated from POMC-A and -B. Alpha-MSH, which has an acetyl group at the N-terminus, led to pigment dispersion in xanthophores, but showed no effect in melanophores. A series of bioassays indicated that acetylation enhances MSH activity in xanthophores, but inhibits it in melanophores, suggesting that receptors for MSHs expressed in xanthophores and melanophores are different from each other.

  20. HYPOXIA-INDUCED GROWTH LIMITATION OF JUVENILE FISHES IN AN ESTUARINE NURSERY: ASSESSMENT OF SMALL-SCALE TEMPORAL DYNAMICS USING RNA:DNA

    EPA Science Inventory

    The ratio of RNA to DNA (RNA:DNA) in white muscle tissue of juvenile summer flounder (Paralichthys dentatus) and weakfish (Cynoscion regalis) was used as a proxy for recent growth rate in an estuarine nursery. Variability in RNA:DNA was examined relative to temporal changes in te...

  1. A Comparison of Pathology Found in Three Marine Fish Treated with Endocrine Disrupting Compounds

    EPA Science Inventory

    Endocrine-disrupting chemicals (EDCs), such as the estrogen estradiol (E2) have been reported to affect fish reproduction. This study histopathologically compared and evaluated the effect of EDCs in three species of treated fish. Juvenile male summer flounder (Paralichthys dentat...

  2. Toxicity of PCB-126 in European flounder (Platichthys flesus) with emphasis on histopathology and cytochrome P4501A induction in several organ systems.

    PubMed

    Grinwis, G C; van den Brandhof, E J; Engelsma, M Y; Kuiper, R V; Vaal, M A; Vethaak, A D; Wester, P W; Vos, J G

    2001-04-01

    A series of experiments was set up to elucidate the effects of pollution on marine and estuarine fish health, since the European flounder (Platichthys flesus) has shown a relatively high prevalence of (pre)neoplastic liver lesions and lymphocystis virus disease in Dutch coastal and estuarine waters. The hypothesis of a causal relationship between pollution and the above-mentioned diseases was supported by results from semi-field experiments. Therefore several laboratory experiments were carried out to substantiate causality further and to identify the xenobiotics that may play a major role in the field. The present study focuses on polychlorinated biphenyls (PCBs). European flounders (Platichthys flesus) were orally exposed to a single dose of 0, 0.5, 5 or 50 mg PCB-126/kg body weight under controlled laboratory conditions. The effects on liver, gills, gastrointestinal tract, gonads, spleen and mesonephros were examined histologically after 16 days. Induction and localization of cytochrome P4501A (CYP1A) immunoreactivity, and effects on hepatocyte proliferation were visualized immunohistochemically. Effects on thymus size were examined by morphometric analysis of serial sections. Three out of five animals of the highest dose group showed haemorrhages in the fins and tail after 16 days. All animals showed reduced activity in the later stages of the experiment, and some animals of the highest dose group discontinued feeding 14 days after exposure. Strong and exposure-related induction of CYP1A immunoreactivity was noted in hepatocytes, endothelium in all organs examined, and epithelium of the digestive tract and mesonephros at PCB-126 levels of 0.5, 5 and 50 mg/kg. In addition, the strong induction of CYP1A immunoreactivity in a distinct population of haematopoietic cells in the mesonephros and in circulating blood is remarkable, and has not been described previously in other fish species. Furthermore, a morphometrically determined significant reduction in relative

  3. Comparison of the effects of dietary single and multi-probiotics on growth, non-specific immune responses and disease resistance in starry flounder, Platichthys stellatus.

    PubMed

    Park, Youngjin; Moniruzzaman, Mohammad; Lee, Seunghan; Hong, Jeongwhui; Won, Seonghun; Lee, Jong Min; Yun, Hyeonho; Kim, Kang-Woong; Ko, Daegyun; Bai, Sungchul C

    2016-12-01

    An 8-week feeding trial was conducted to evaluate the effects of dietary probiotics on growth performance and non-specific immune responses in starry flounder, Platichthys stellatus. Fish averaging 46.5 ± 0.65 g (mean ± SD) were fed one of the six experimental diets; one control (Cont), and five other diets were prepared by supplementing single-probiotics 1 (Bacillus subtilis; SP1, 2 × 10(9) CFU kg(-1) diet), single-probiotics 2 (Bacillus licheniformis; SP2, 2 × 10(9) CFU kg(-1) diet), multi-probiotics 1 (Bacillus subtilis + Bacillus licheniformis; MP1, 2 × 10(9) CFU kg(-1) diet), multi-probiotics 2 (commercial probiotics; Bacillus subtills + Bacillus licheniformis + Paenibacillus polymyxa + Aspergillus oryzae + Saccharomyces cerevisiae; MP2, 2 × 10(9) CFU kg(-1) diet) and oxytetracycline (OTC) at 5 g OTC kg(-1) diet. At the end of 8 weeks feeding trial, weight gain (WG) and specific growth rate (SGR) of fish fed SP1, MP1 and MP2 diets were significantly higher than those of fish fed control diet (P < 0.05). Superoxide dismutase (SOD) activity of fish fed MP2 diet was significantly higher than those of fish fed OTC diet (P < 0.05). Nitro blue tetrazolium (NBT) activity and lysozyme activity of fish fed SP1, MP1 and MP2 diets were significantly higher than those of fish fed OTC diet (P < 0.05). However, there was no significant difference among fish fed SP1, SP2, MP1 and MP2 diets. During the Edwardsiella tarda challenge test, the first mortality occurred on day 2. After the 14 days challenge test, cumulative survival rate of fish fed MP1 and MP2 diets were significantly higher than those of fish fed control diet (P < 0.05). However, there was no significant difference among fish fed SP1, SP2, MP1, MP2 and OTC diets in survival rate at the termination of the challenge test. Although there was little advantage in immunological parameters with fish fed MP diets, single and multi-probiotics were equally effective

  4. Variation patterns in individual fish responses to chemical stress among estuaries, seasons and genders: the case of the European flounder (Platichthys flesus) in the Bay of Biscay.

    PubMed

    Laroche, Jean; Gauthier, Olivier; Quiniou, Louis; Devaux, Alain; Bony, Sylvie; Evrard, Estérine; Cachot, Jérôme; Chérel, Yan; Larcher, Thibaut; Riso, Ricardo; Pichereau, Vianney; Devier, Marie Hélène; Budzinski, Hélène

    2013-02-01

    The objective was to describe and model variation patterns in individual fish responses to contaminants among estuaries, season and gender. Two hundred twenty-seven adult European flounders were collected in two seasons (winter and summer) in four estuaries along the Bay of Biscay (South West France), focusing on a pristine system (the Ster), vs. three estuaries displaying contrasted levels of contaminants (the Vilaine, Loire and Gironde). Twenty-three variables were measured by fish, considering the load of contaminants (liver metals, liver and muscle persistent organic pollutants, muscle polycyclic aromatic hydrocarbons); the gene expression (Cyt C oxydase, ATPase, BHMT, Cyt P450 1A1, ferritin); the blood genotoxicity (Comet test); and liver histology (foci of cellular alteration-tumour, steatosis, inflammation, abnormal glycogen storage). Canonical redundancy analysis (RDA) was used to model these variables using gender, season and estuary of origin as explanatory variables. The results underlined the homogeneity of fish responses within the pristine site (Ster) and more important seasonal variability within the three contaminated systems. The complete model RDA was significant and explained 35 % of total variance. Estuary and season respectively explained 30 and 5 % of the total independent variation components, whilst gender was not a significant factor. The first axis of the RDA explains nearly 27 % of the total variance and mostly represents a gradient of contamination. The links between the load of contaminants, the expression of several genes and the biomarkers were analysed considering different levels of chemical stress and a possible multi-stress, particularly in the Vilaine estuary.

  5. Novel L-amino acid oxidase with antibacterial activity against methicillin-resistant Staphylococcus aureus isolated from epidermal mucus of the flounder Platichthys stellatus.

    PubMed

    Kasai, Kosuke; Ishikawa, Takashi; Komata, Takafumi; Fukuchi, Kaori; Chiba, Mitsuru; Nozaka, Hiroyuki; Nakamura, Toshiya; Sato, Tatsusuke; Miura, Tomisato

    2010-01-01

    Fish produce mucus substances as a defensive outer barrier against environmental xenobiotics and predators. Recently, we found a bioactive protein in the mucus layer of the flounder Platichthys stellatus, which showed antibacterial activity against Staphylococcus epidermidis, Staphylococcus aureus and methicillin-resistant S. aureus. In this study, we isolated and identified the antibacterial protein from the mucus components of P. stellatus using a series of column chromatography steps. We then performed gel electrophoresis and cDNA cloning to characterize the protein. The antibacterial protein in the mucus had a molecular mass of approximately 52 kDa with an isoelectric point of 5.3, and cDNA sequencing showed that it corresponded completely with the peptide sequence of antibacterial protein from the gill. A BLAST search suggested that the cDNA encoded an antibacterial protein sharing identity with a number of L-amino acid oxidases (LAAOs) and possessing several conserved motifs found in flavoproteins. RT-PCR using a specific primer, and immunohistochemical analysis with anti-LAAO IgG, demonstrated tissue-specific expression and localization in the gill. Moreover, the anti-LAAO IgG was able to neutralize the antibacterial activity of the protein against methicillin-resistant S. aureus. Thus, we demonstrated that this antibacterial protein, identified from P. stellatus-derived epidermal mucus, is a novel LAAO-like protein with antibacterial activity, similar to snake LAAOs.

  6. Nuclear changes in blood, early liver anomalies and hepatocellular cancers in flounder (Platichthys flesus L.) as prognostic indicator for a higher cancer risk?

    PubMed

    Köhler, Angela; Ellesat, Kathrin

    2008-07-01

    Nuclear changes (micronuclei) in blood are a well-established biomarker of toxic injury and related genotoxicity in mussel, fish and humans, as well. Yet, the relationship between the frequencies of micronuclei in blood and nuclear changes in liver cells itself and the higher potential risk to develop liver cancer is not yet fully implemented. We analysed and diagnosed macroscopic liver changes and H&E and Feulgen stained histological liver sections (2 microm of thickness) together with blood smears (stained with Sytox Green) from same individuals in flounder caught along a well-known contaminant gradient in the North Sea. Results showed an increase in micronuclei frequencies in blood at the more contaminated sites and higher frequencies of macroscopically visible neoplastic liver changes. In livers of the same individuals, nuclear changes were diagnosed in early to degenerative liver lesion, extra-focal tissue surrounding neoplastic lesion and various stages during cancer progression from early neoplastic foci, benign adenomas and malignant carcinomas. The aim of this approach is to expand diagnostic criteria, well-established in the frame of BEQUALM to nuclear changes which might help diagnosis of malignancies in doubtful cases.

  7. Distribution and elimination of (/sup 14/C)-hexachlorobenzene after single oral exposure in cod (Gadus morhua) and flounder (Platichthys flesus)

    SciTech Connect

    Ingebrigtsen, K.; Solbakken, J.E.

    1985-01-01

    Distribution and elimination of hexachlorobenzene (HCB) after administration to COD (Gadus morhua) of a single oral dose of 5 microCi (/sup 14/C)HCB/100 g body weight were studied by whole-body autoradiography and liquid scintillation counting. To obtain some information on the physicochemical properties of the radiolabeled compounds, whole-body autoradiography was performed exposing parallel sagittal sections, treated at -20/sup 0/C, evaporated at 50/sup 0/C, and extracted separately with polar and nonpolar solvents. The highest concentration of radioactivity was found in the liver, the bile, and the central nervous system (CNS). Radioactivity in the liver and CNS, which was completely evaporable, was considered to represent the highly volatile HCB itself, and/or metabolites with high vapor pressure. No part of radioactivity in bile was evaporable, but it was completely extractable with water. Radioactivity in the intestinal content, the skin, and the uveal tract of the eye was partly evaporable. No radioactivity remained in any tissue after extraction with polar and nonpolar solvents. The rate of elimination was slow, and substantial amounts remained in the body 60 d after administration. In addition to bile excretion of nonevaporable, water-soluble radioactivity, a possible excretion through the intestinal mucosa was suggested. Whole-body autoradiography of female flounders (Platichthys flesus) revealed a high content of radioactivity in the developing eggs.

  8. Bioindicators of contaminant exposure, liver pathology, and reproductive development in prespawning female winter flounder ('Pleuronectes americanus') from urban and nonurban estuaries on the northeast Atlantic coast. Technical memo

    SciTech Connect

    Johnson, L.L.; Stein, J.E.; Collier, T.K.; Casillas, E.; McCain, B.

    1992-08-01

    Relationships between liver pathology and ovarian development, and exposure to xenobiotic compounds were evaluated in prespawning female winter flounder (Pleuronectes americanus, formerly Pseudopleuronectes americanus) sampled from 11 sites on the Northeast coast of the United States during the 1988 and 1989 spawning seasons. Sediments from three sites exhibited a wide range in concentrations of xenobiotic compounds (e.g. concentrations of polycyclic aromatic hydrocarbons (PAHs) ranged from 20 to 50,000 ng/g dry weight and concentrations of polychlorinated biphenyls (PCBs) ranged from 2 to 1,400 ng/g dry weight), with the sites in Boston Harbor and Raritan Bay the most heavily contaminated. The following parameters associated with ovarian development were measured: ovarian developmental stage, ovarian atresia, gonadosomatic index, plasma estradiol, fecundity, and egg weight. Contaminant exposure was assessed by measuring concentrations of fluorescent aromatic compounds (FACs) in the bile; hepatic aryl hydrocarbon hydroxylase (AHH) activity; concentrations of polychlorinated biphenyls (PCBs) in liver, ovary, and brain; and levels of xenobiotic-DNA adducts in liver tissue. In general, indicators of contaminant exposure were elevated and prevalences of suspected toxicopathic lesions were highest in fish from sites within Boston Harbor and Raritan Bay.

  9. Anti-Microbial, Anti-Biofilm Activities and Cell Selectivity of the NRC-16 Peptide Derived from Witch Flounder, Glyptocephalus cynoglossus

    PubMed Central

    Gopal, Ramamourthy; Lee, Jun Ho; Kim, Young Gwon; Kim, Myeong-Sun; Seo, Chang Ho; Park, Yoonkyung

    2013-01-01

    Previous studies had identified novel antimicrobial peptides derived from witch flounder. In this work, we extended the search for the activity of peptide that showed antibacterial activity on clinically isolated bacterial cells and bacterial biofilm. Pseudomonas aeruginosa was obtained from otitis media and cholelithiasis patients, while Staphylococcus aureus was isolated from otitis media patients. We found that synthetic peptide NRC-16 displays antimicrobial activity and is not sensitive to salt during its bactericidal activity. Interestingly, this peptide also led to significant inhibition of biofilm formation at a concentration of 4–16 μM. NRC-16 peptide is able to block biofilm formation at concentrations just above its minimum inhibitory concentration while conventional antibiotics did not inhibit the biofilm formation except ciprofloxacin and piperacillin. It did not cause significant lysis of human RBC, and is not cytotoxic to HaCaT cells and RAW264.7 cells, thereby indicating its selective antimicrobial activity. In addition, the peptide’s binding and permeation activities were assessed by tryptophan fluorescence, calcein leakage and circular dichroism using model mammalian membranes composed of phosphatidylcholine (PC), PC/cholesterol (CH) and PC/sphingomyelin (SM). These experiments confirmed that NRC-16 does not interact with any of the liposomes but the control peptide melittin did. Taken together, we found that NRC-16 has potent antimicrobial and antibiofilm activities with less cytotoxicity, and thus can be considered for treatment of microbial infection in the future. PMID:23760014

  10. Comparison of the in vitro and in vivo toxic effects of three sizes of zinc oxide (ZnO) particles using flounder gill (FG) cells and zebrafish embryos

    NASA Astrophysics Data System (ADS)

    Han, Li; Zhai, Yanan; Liu, Yang; Hao, Linhua; Guo, Huarong

    2017-02-01

    Nano-sized zinc oxide (nZnO) particles are one kind of the most commonly used metal oxide nanoparticles (NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles (ϕ 30 nm, 80-150 nm and 2 μm) in the flounder gill (FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn2+ to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size- and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn2+ ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size- and concentration- dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.

  11. Daily rhythms of urotensin I and II gene expression and hormone secretion in the caudal neurosecretory system of the euryhaline flounder (Platichthys flesus).

    PubMed

    Lu, Weiqun; Zhang, Ying; Xiong, Jianghong; Balment, Richard

    2013-07-01

    The caudal neurosecretory system (CNSS) is a unique neuroendocrine structure for environmental adaptation in fish, and is the major site of expression and secretion of urotensin I (UI) and II (UII). This study examined daily changes in mRNA expression and the secretion profile of UI and UII in the CNSS. Daily rhythms were observed in mRNA level of CNSS UI, urophysis UI, plasma UII, glucose, potassium and sodium. No statistically significant (Cosinor, P>0.05) diel rhythmicity in mRNA level of CNSS UII, urophysis UII, cortisol, lactate, osmolality and chloride were detected. The calculated acrophase of sodium, cortisol, plasma UII, urophysis UII, urophysis UI and mRNA level of CNSS UI rhythms were recorded at 13:04 h, 13:39 h, 14:45 h, 15:27 h, 14:41 h and 14:39 h, respectively and a positive relationship was evident among them. The acrophase of glucose and potassium rhythms were recorded at 18:57 h and 22:35 h, respectively. The glucose levels increased progressively at the onset of the UII surge at 15:00 h and reached peak values at dusk. The results support the hypothesis that the CNSS may play a role in the control of co-ordinated daily changes in energy mobilization, nutritional behavior and osmoregulatory systems in euryhaline flounder. Our findings described for the first time the existence of daily rhythms of CNSS hormone expression and secretion in Platichthys flesus. These results reveal the importance of taking into account the time of day when assessing stress responses and evaluating UI and UII as physiological indicators of stress in this species.

  12. Regulation of antifreeze protein messenger RNA and a female-specific messenger RNA in winter flounder: Evidence for temperature and photoperiod effects

    SciTech Connect

    Price, J.L.

    1988-01-01

    Northern blot hybridizations showed that mRNA{sub f} is female-specific, and that both mRNAs are liver-specific and expressed at high levels only during the fall and winter in the wild. When warm-acclimated flounder (18C) were acclimated over 2 days to low temperature (4 C) and short photoperiod in July and October, high levels of AF mRNA accumulated within 4-10 days. Low levels were found in fish at high temperature at any time, on long photoperiod after acclimation to low temperature in July, or continuously at 4 C from March until September. A temperature increase in January resulted in a dramatic decrease in the levels of AF mRNA within 5 days. Beta actin mRNA, mRNA{sub f} and most mRNAs translated in a reticulocyte lysate did not change in abundance after temperature increases or decreases. Synthesis of AF mRNA in liver slices was investigated by Northern blot hybridization and hybridization of {sup 32}P-labeled RNA to AF cDNA. Liver slices from cold-acclimated January fish expressed high levels of AF mRNA initially at 4 C and lower levels at 18 C. AF mRNA expression was turned off in tissue from warm-acclimated fish but was progressively induced after long 4 C incubations in vitro in livers from fall fish but not from spring fish. Temperature and photoperiod act either as zeitgebers, which set the phase of an endogenous rhythm, or as more direct signals that stimulate a transient accumulation of AF mRNA.

  13. Parasites of the flounder Platichthys flesus (L.) from the German Bight, North Sea, and their potential use in ecosystem monitoring. A. Infection characteristics of potential indicator species

    NASA Astrophysics Data System (ADS)

    Schmidt, V.; Zander, S.; Körting, W.; Steinhagen, D.

    2003-10-01

    As part of integrated biological-effect monitoring, the parasite fauna of the flounder Platichthys flesus (L.) was investigated at five locations in the German Bight, with a view to using parasite species as bio-indicators. Over a period of 6 years, parasites from 30 different taxa were identified, but only 7 taxa of the parasite community occurred regularly at all locations and in sufficient abundance that they could be considered as potential indicator species. These species were the ciliophoran Trichodina spp., the copepods Acanthochondria cornuta, Lepeophtheirus pectoralis and Lernaeocera branchialis, the helminths Zoogonoides viviparus and Cucullanus heterochrous and metacercaria of an unidentified digenean species. Infection characteristics of these parasites are presented, with a comparison of the results from individual sampling periods and those of the long-term data set. Natural influences on the infection levels, such as temporal variations, habitat conditions and host-related factors, were evaluated. All of these parasite species showed significant differences in their infection levels between the Elbe estuary, as the most polluted site, and the less polluted coastal and marine locations: Helgoland, Outer Eider estuary and Spiekeroog, especially in the long-term data set. Gradual differences between the Elbe, the Outer Eider and Helgoland, which were not detected in individual sampling periods, also became evident in the pooled-data set. These were found in the prevalence of Trichodina spp., A. cornuta, Z. viviparus and C. heterochrous. Although salinity is considered as the most important natural factor, influencing the distribution pattern of the majority of the potential indicator species, infection levels of most of these species differed between locations with similar salinity conditions. Infection levels corresponded to a contamination gradient (Elbe > Inner Eider, Outer Eider > Helgoland) established across the locations. Seasonal variation in

  14. Parasites of flounder (Platichthys flesus L.) from the German Bight, North Sea, and their potential use in biological effects monitoring. C. Pollution effects on the parasite community and a comparison to biomarker responses

    NASA Astrophysics Data System (ADS)

    Schmidt, V.; Zander, S.; Körting, W.; Broeg, K.; von Westernhagen, H.; Dizer, H.; Hansen, P. D.; Skouras, A.; Steinhagen, D.

    2003-10-01

    In the frame of an integrated biological effect monitoring programme, the parasite community of flounder (Platichthys flesus) was investigated at different locations in the German Bight from 1995 to 2000. In order to assess the impact of environmental contamination caused by anthropogenic activities on the parasite community, selected parasitological parameters that displayed significant differences between the sampling sites were subjected to correlation analyses with site-specific contamination and individual pollution loads of their fish hosts. In addition, correlation analyses were conducted with the responses of selected genetic, biochemical, histopathological, physiological and immunological parameters of fish, used as potential biomarkers. In total, 802 flounder were analysed for these parameters. Information on the chemical background at the sampling sites was derived from sediment samples and from 120 samples of blue mussel (Mytilus edulis) tissue, collected at each of the sampling sites. Based on chemical data available from the sediment and blue mussel samples, a pollution gradient could be established between the sampling sites for individual contaminants. The relative abundance of Acanthochondria cornuta, Cucullanus heterochrous and Zoogonoides viviparus, and the community measures species richness and number of heteroxenous species decreased with increasing concentrations of individual heavy metals or hydrocarbons in sediment and blue mussel samples. Most of the parasitological parameters significantly reflected the established site-specific contamination gradient, when data were pooled over all sampling campaigns. Significant correlations were also found with the contamination level of individual flounder. The parasitological parameters included the parasite species Lepeophtheirus pectoralis and Lernaeocera branchialis, which were not correlated to site-specific contamination. Several biomarkers were significantly correlated to the abundance of

  15. Continuous illumination through larval development suppresses dopamine synthesis in the suprachiasmatic nucleus, causing activation of α-MSH synthesis in the pituitary and abnormal metamorphic skin pigmentation in flounder.

    PubMed

    Itoh, Kae; Washio, Youhei; Fujinami, Yuichiro; Shimizu, Daisuke; Uji, Susumu; Yokoi, Hayato; Suzuki, Tohru

    2012-04-01

    In order to better understand the endocrine aberrations related to abnormal metamorphic pigmentation that appear in flounder larvae reared in tanks, this study examined the effects of continuous 24-h illumination (LL) through larval development on the expression of tyrosine hydroxylase-1 (th1), proopiomelanocortin (pomc), α-melanophore-stimulating hormone (α-MSH) and melanin concentrating hormone (MCH), which are known to participate in the control of background adaptation of body color. We observed two conspicuous deviations in the endocrine system under LL when compared with natural light conditions (LD). First, LL severely suppressed th1 expression in the dopaminergic neurons in the anterior diencephalon, including the suprachiasmatic nucleus (SCN). Second, pomc and α-MSH expression in the pars intermedia melanotrophs was enhanced by LL. Skin color was paler under LL than LD before metamorphic pigmentation, and abnormal metamorphic pigmentation occurred at a higher ratio in LL. We therefore hypothesize that continuous LL inhibited dopamine synthesis in the SCN, which resulted in up-regulation of pomc mRNA expression in the melanotrophs. In spite of the up-regulation of pomc in the melanotrophs, larval skin was adjusted to be pale by MCH which was not affected by LL. Accumulation of α-MSH in the melanotrophs is caused by uncoupling of α-MSH synthesis and secretion due to inhibitory role of MCH on α-MSH secretion, which results in abnormal metamorphic pigmentation by affecting differentiation of adult-type melanophores. Our data demonstrate that continuous illumination at the post-embryonic stage has negative effects on the neuroendocrine system and pituitary in flounder.

  16. Fecundity estimation by oocyte packing density formulae in determinate and indeterminate spawners: Theoretical considerations and applications

    NASA Astrophysics Data System (ADS)

    Kurita, Yutaka; Kjesbu, Olav S.

    2009-02-01

    This paper explores why the 'Auto-diametric method', currently used in many laboratories to quickly estimate fish fecundity, works well on marine species with a determinate reproductive style but much less so on species with an indeterminate reproductive style. Algorithms describing links between potentially important explanatory variables to estimate fecundity were first established, and these were followed by practical observations in order to validate the method under two extreme situations: 1) straightforward fecundity estimation in a determinate, single-batch spawner: Atlantic herring (AH) Clupea harengus and 2) challenging fecundity estimation in an indeterminate, multiple-batch spawner: Japanese flounder (JF) Paralichthys olivaceus. The Auto-diametric method relies on the successful prediction of the number of vitellogenic oocytes (VTO) per gram ovary (oocyte packing density; OPD) from the mean VTO diameter. Theoretically, OPD could be reproduced by the following four variables; OD V (volume-based mean VTO diameter, which deviates from arithmetic mean VTO diameter), VFvto (volume fraction of VTO in the ovary), ρo (specific gravity of the ovary) and k (VTO shape, i.e. ratio of long and short oocyte axes). VF vto, ρ o and k were tested in relation to growth in OD V. The dynamic range throughout maturation was clearly highest in VF vto. As a result, OPD was mainly influenced by OD V and secondly by VFvto. Log (OPD) for AH decreased as log (OD V) increased, while log (OPD) for JF first increased during early vitellogenesis, then decreased during late vitellogenesis and spawning as log (OD V) increased. These linear regressions thus behaved statistically differently between species, and associated residuals fluctuated more for JF than for AH. We conclude that the OPD-OD V relationship may be better expressed by several curves that cover different parts of the maturation cycle rather than by one curve that cover all these parts. This seems to be particularly

  17. Effect of ammonia-N and pathogen challenge on complement component 8α and 8β expression in the darkbarbel catfish Pelteobagrus vachellii.

    PubMed

    Qin, Chuanjie; Shao, Ting; Zhao, Daxian; Duan, Huiguo; Wen, Zhengyong; Yuan, Dengyue; Li, Huatao; Qi, Zemin

    2017-03-01

    The complement components C8α and C8β mediate the formation of the membrane attack complex (MAC) to resist pathogenic bacteria and play important roles in innate immunity. Full-length complement C8α (Pv-C8α) and C8β (Pv-C8β) cDNA were identified in the darkbarbel catfish Pelteobagrus vachellii, and their mRNA expression levels were analyzed after ammonia-N and pathogen treatment. The Pv-C8α gene contained 1983 bp, including a 1794-bp open reading frame (ORF) encoding 598 amino acids. The Pv-C8β gene contained 1952 bp, including a 1761-bp ORF encoding 587 amino acids. Pv-C8α and Pv-C8β had the highest amino acid identity with rainbow trout Oncorhynchus mykiss C8α (62%) and Japanese flounder Paralichthys olivaceus C8β (83%), respectively. Sequence analysis indicated that both Pv-C8α and Pv-C8β contained a thrombospondin type-1 (TSP1) domain, a low-density lipoprotein receptor class A (LDLR-A) domain, a membrane attack complex/perforin (MACPF) domain and an epidermal growth factor-like (EGF-like) domain. In addition, Pv-C8α and Pv-C8β were mainly distributed in the liver, head kidney, spleen, and eggs. Under ammonia-N stress, the Pv-C8α and Pv-C8β mRNA levels significantly decreased (P < 0.05), with minimum levels, respectively, attained at 24 and 48 h in the liver, 48 and 24 h in the head kidney, and 24 and 24 h in the spleen. After Aeromonas hydrophila challenge, the Pv-C8α and Pv-C8β mRNA levels significantly increased (P < 0.05), with maximum levels, respectively, attained at 48 and 24 h in the liver, 24 and 48 h in the head kidney, and 48 and 48 h in the spleen. The present study indicated that Pv-C8α and Pv-C8β exhibited important immune responses to infection and that ammonia-N in water decreased the immune responses of Pv-C8α and Pv-C8β.

  18. Incidence of three Kudoa spp., K. neothunni, K. hexapunctata, and K. thunni (Myxosporea: Multivalvulida), in Thunnus tunas distributed in the western Pacific Ocean.

    PubMed

    Kasai, Akihiro; Tsuduki, Hideaki; Jimenez, Lea Angsinco; Li, Ying-Chun; Tanaka, Shuhei; Sato, Hiroshi

    2017-04-01

    A variety of tunas of the genus Thunnus are consumed daily in Japan as sliced raw fish (sashimi and sushi). The consumption of fresh sliced raw fish, i.e., unfrozen or uncooked, can sometimes cause food poisoning that is manifested by transient diarrhea and vomiting for a single day. One of the causes of this type of food poisoning has been identified as live Kudoa septempunctata (Myxosporea: Multivalvulida) in the olive flounder (Paralichthys olivaceus). Furthermore, raw slices of fresh tunas are highly suspected to be a possible causative fish of similar food poisoning in Japan. In the present study, we conducted a survey of kudoid infections in tunas (the yellowfin tuna Thunnus albacares, the Pacific bluefin tuna Thunnus orientalis, and the longtail tuna Thunnus tonggol) fished in the western Pacific Ocean off Japan and several East Asian countries and characterized morphologically and genetically the kudoid myxospores in pseudocysts or cysts dispersed in the trunk muscles. Pseudocysts of solely Kudoa hexapunctata were identified in the Pacific bluefin tuna (four isolates), whereas in the yellowfin tuna (21 isolates) pseudocysts of Kudoa neothunni and K. hexapunctata were detected at a ratio of 15:6, respectively, in addition to cyst-forming Kudoa thunni in five yellowfin tunas. In the trunk muscles of six longtail tunas examined, pseudocysts of K. neothunni (all six fish) and K. hexapunctata (two fish) were densely dispersed. The myxospores of K. neothunni found in these longtail tunas had seven shell valves and polar capsules (SV/PC) instead of the more common six SV/PC arranged symmetrically. Nucleotide sequences of the 18S and 28S ribosomal RNA gene (rDNA), some with the internal transcribed spacer regions as well, of K. hexapunctata and K. neothunni from the three Thunnus spp., including the seven-SV/PC morphotype, were very similar to previously characterized nucleotide sequences of each species, whereas the 18S and 28S rDNA of four isolates of K. thunni

  19. Contribution of hepatic cytochrome CYP1A and metallothionein mRNA abundance to biomonitoring-A case study with European flounder (Platichthys flesus) from the Gulf of Gdańsk.

    PubMed

    Kopecka-Pilarczyk, Justyna; Schirmer, Kristin

    2016-10-01

    The aim of the research was to explore the contribution of hepatic cytochrome CYP1A and metallothionein (MT) mRNA expression to biological effect monitoring. The study was conducted in the European flounder (Platichthys flesus) from the Gulf of Gdańsk. mRNA abundance was measured using reverse transcriptase polymerase chain reaction (RT-PCR) in liver RNA of fish sampled from three coastal stations and from one offshore station in the inner Gulf. The contribution of the mRNA-based biomarkers to the assessment of the environment was determined in conjunction with a selection of commonly applied biochemical markers: 7-ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST), catalase (CAT), metallothioneins (MT), fluorescent aromatic compounds (FACs), all measured in the same individual fish. The mRNA biomarkers contributed to the separation between the sampling sites, but no correlations between CYP1A mRNA and EROD nor between MT mRNA and MT proteins were found, which should be attributed to the different levels these biomarkers correspond to and to the differences in factors that may affect them. One case of strong correlation between CYP1A mRNA and FACs was encountered. The overall results of this study suggest that biomarkers measured at the mRNA abundance level constitute a valuable addition to biomonitoring studies by providing additional information and contributing to the differentiation of results.

  20. Aspects of the hormonal regulation of appetite in fish with emphasis on goldfish, Atlantic cod and winter flounder: notes on actions and responses to nutritional, environmental and reproductive changes.

    PubMed

    Volkoff, Hélène; Xu, Meiyu; MacDonald, Erin; Hoskins, Leah

    2009-05-01

    In vertebrates including fish, food intake regulation involves intricate networks of hormones produced by both brain and peripheral tissues. Under optimum conditions, nutritional intake is adequate for basal metabolic needs, growth, development, reproduction, and deposition of energy stores. As fish represent a very diverse group, different fish species live in very different environments and are exposed to variations in a wide range of factors, including not only internal factors, such as nutritional/metabolic status and reproductive events but also environmental factors, such as temperature and photoperiod. These physiological responses often include changes in appetite that might occur through modulations of the gene expression and action of feeding-regulating hormones. Despite recent advances, our current understanding of the regulation of feeding in fish is still limited and based primarily on studies involving a few fish species. This review will give a brief overview of our current knowledge of the regulation of feeding by three central (NPY, OX and CART) and two peripheral (ghrelin and GRP) appetite-related factors in a freshwater species, the goldfish (Carassius auratus) and two marine species, cod (Gadus morhua) and winter flounder (Pleuronectes americanus).