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Sample records for atlantic cod gadus

  1. Gillnet selectivity for North Sea Atlantic cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Hovgård, Holger; Lassen, H.; Madsen, Niels

    1999-01-01

    Gillnet selectivity curves for North Sea Atlantic cod (Gadus morhua) were fitted to catch data obtained with six different mesh sizes. The selectivity curves investigated included frequently used selectivity models following the normal, lognormal, and gamma distributions. Another group...

  2. Molecular responce of Atlantic cod's ( Gadus morhua L.) cypia ...

    African Journals Online (AJOL)

    A molecular response study was conducted to determine whether Polychlorinated Biphenyl or PCB (Clophen A40) had an effect on the induction of the zona radiata, prolactin and cytochrome P4501A (CYP1A) mRNAs in matured Atlantic cod (Gadus morhua). A total of 127 fishes were maintained under natural photoperiod ...

  3. Excess post hypoxic oxygen consumption in Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Plambech, Marie; Deurs, Mikael van; Steffensen, J.F.

    2013-01-01

    Atlantic cod Gadus morhua experienced oxygen deficit (DO2 ) when exposed to oxygen levels below their critical level (c. 73% of pcrit) and subsequent excess post-hypoxic oxygen consumption (CEPHO) upon return to normoxic conditions, indicative of an oxygen debt. The mean±s.e. CEPHO:DO2 was 6...

  4. A statistical discrimination method using sagittal otolith dimensions between sibling species of juvenile cod Gadus morhua and Gadus ogac from the North-West Atlantic

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Methven, D. A.; Kristensen, Kasper

    2010-01-01

    Greenland cod (Gadus ogac) and Atlantic cod (Gadus morhua) co-exist and are caught in the same fisheries in coastal waters off western Greenland and eastern Canada. Juveniles (......Greenland cod (Gadus ogac) and Atlantic cod (Gadus morhua) co-exist and are caught in the same fisheries in coastal waters off western Greenland and eastern Canada. Juveniles (...

  5. Experimental mycobacteriosis in Atlantic cod, Gadus morhua L.

    Science.gov (United States)

    Zerihun, M A; Colquhoun, D J; Poppe, T T

    2012-05-01

    Piscine mycobacteriosis causes losses in a number of fish species both in the wild and in aquaculture worldwide. Mycobacterium salmoniphilum infections have on several occasions been reported in farmed Atlantic salmon, Salmo salar L. The present study tested and confirmed the susceptibility of Atlantic cod, Gadus morhua L., an important yet relatively novel aquaculture species, to infection with M. salmoniphilum. Atlantic cod injected intraperitoneally with a suspension of this bacterium were maintained together with cohabitant (COH) fish in a flow-through marine water system at 10-11 °C. The fish were supervised daily and samples taken at 2, 7, 14, 23, 34 and 53 weeks post-infection and examined pathologically, bacteriologically and using molecular biology. Injected mycobacteria were re-isolated in high concentrations from both injected and COH fish groups. Death attributable to mycobacterial infection was observed in both injected (47%) and COH (28%) fish groups. Extensive development of granuloma in visceral organs, mainly the mesenteries, spleen, kidney and liver (lesser extent) and at later stages of the infection in heart tissues and gills, was observed in both injected and COH fish. Granulomas underwent a temporal progression of distinct morphological stages, culminating in well-circumscribed lesions surrounded by normal or healing tissue. Acid-fast bacilli were detected in both granulomas and non-granulomatous tissues. This study confirms that Atlantic cod is highly susceptible to M. salmoniphilum infection and that this bacterial species may be a threat to cod both in the wild and in the aquaculture. © 2012 Blackwell Publishing Ltd.

  6. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae

    Science.gov (United States)

    Penglase, S; Harboe, T; Sæle, Ø; Helland, S; Nordgreen, A

    2013-01-01

    Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I), at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua) were fed rotifers enriched to intermediate (26 mg I kg-1 dry weight; MI group) or copepod (129 mg I kg-1 DW; HI group) I levels and compared to cod larvae fed control rotifers (0.6 mg I kg-1 DW). Larval I concentrations were increased by 3 (MI) and 7 (HI) fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg-1 DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg-1 DW. PMID:23638355

  7. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua larvae

    Directory of Open Access Journals (Sweden)

    S Penglase

    2013-02-01

    Full Text Available Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I, at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua were fed rotifers enriched to intermediate (26 mg I kg-1 dry weight; MI group or copepod (129 mg I kg-1 DW; HI group I levels and compared to cod larvae fed control rotifers (0.6 mg I kg-1 DW. Larval I concentrations were increased by 3 (MI and 7 (HI fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg-1 DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg-1 DW.

  8. Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Penglase, S; Harboe, T; Sæle, O; Helland, S; Nordgreen, A; Hamre, K

    2013-01-01

    Copepods as feed promote better growth and development in marine fish larvae than rotifers. However, unlike rotifers, copepods contain several minerals such as iodine (I), at potentially toxic levels. Iodine is an essential trace element and both under and over supply of I can inhibit the production of the I containing thyroid hormones. It is unknown whether marine fish larvae require copepod levels of I or if mechanisms are present that prevent I toxicity. In this study, larval Atlantic cod (Gadus morhua) were fed rotifers enriched to intermediate (26 mg I kg(-1) dry weight; MI group) or copepod (129 mg I kg(-1) DW; HI group) I levels and compared to cod larvae fed control rotifers (0.6 mg I kg(-1) DW). Larval I concentrations were increased by 3 (MI) and 7 (HI) fold compared to controls during the rotifer feeding period. No differences in growth were observed, but the HI diet increased thyroid follicle colloid to epithelium ratios, and affected the essential element concentrations of larvae compared to the other groups. The thyroid follicle morphology in the HI larvae is typical of colloid goitre, a condition resulting from excessive I intake, even though whole body I levels were below those found previously in copepod fed cod larvae. This is the first observation of dietary induced I toxicity in fish, and suggests I toxicity may be determined to a greater extent by bioavailability and nutrient interactions than by total body I concentrations in fish larvae. Rotifers with 0.6 mg I kg(-1) DW appeared sufficient to prevent gross signs of I deficiency in cod larvae reared with continuous water exchange, while modelling of cod larvae versus rotifer I levels suggests that optimum I levels in rotifers for cod larvae is 3.5 mg I kg(-1) DW.

  9. Authentication of Atlantic cod (Gadus morhua) using real time PCR.

    Science.gov (United States)

    Herrero, Beatriz; Madriñán, María; Vieites, Juan M; Espiñeira, Montserrat

    2010-04-28

    This work describes the development of a real-time polymerase chain reaction (RT-PCR) system for the detection and identification of Atlantic cod (Gadus morhua). Among the advantages of this technique, it is worth highlighting that this is reliable in terms of specificity and sensitivity. The TaqMan real-time PCR is the simplest, fastest testing process and has the highest potential for automation, therefore representing the currently most suitable method for screening, allowing the detection of fraudulent or unintentional mislabeling of this species. The method can be applied to all kinds of products, fresh, frozen, and processed products, including those undergoing intensive processes of transformation. The developed methodology using specific primer-probe set was validated and further applied to 40 commercial samples labeled as cod in order to determinate if the species used for their manufacturing corresponded to G. morhua, detecting 20% that were incorrectly labeled. A C(t) value of about 19 was obtained when G. morhua was present. In samples with a species mixture, all samples that had a fluorescence signal were positive (C(t) fisheries control.

  10. Thermal niche of Atlantic cod Gadus morhua: limits, tolerance and optima

    DEFF Research Database (Denmark)

    Righton, David A.; Andersen, Ken Haste; Neat, Francis

    2010-01-01

    Recent studies in the marine environment have suggested that the limited phenotypic plasticity of cold-adapted species such as Atlantic cod Gadus morhua L. will cause distributions to shift toward the poles in response to rising sea temperatures. Some cod stocks are predicted to collapse, but thi...

  11. Proteome reference map of the skin mucus of Atlantic cod (Gadus morhua) revealing immune competent molecules

    NARCIS (Netherlands)

    Rajan, B.; Fernandes, J.M.O.; Caipang, C.M.A.; Kiron, V.; Rombout, J.H.W.M.; Brinchmann, M.

    2011-01-01

    The skin mucosal proteome of Atlantic cod (Gadus morhua) was mapped using a 2D PAGE, LC–MS/MS coupled approach. Mucosal proteins from naive fish were identified primarily by similarity searches across various cod EST databases. The identified proteins were clustered into 8 groups based on gene

  12. Transcriptome analysis of gill tissue of Atlantic cod Gadus morhua L. from the Baltic Sea.

    Science.gov (United States)

    Małachowicz, Magdalena; Kijewska, Agnieszka; Wenne, Roman

    2015-10-01

    The Atlantic cod (Gadus morhua L.) is one of the most ecologically and economically important marine fish species in the North Atlantic Ocean. Using Roche GS-FLX 454 pyrosequencing technique 962,516 reads, representing 379Mbp of the Baltic cod transcriptome, were obtained. Data was assembled into 14,029 contigs of which 100% displayed homology to the Atlantic cod transcriptome. Despite a high similarity between transcripts, evidence for significant differences between Baltic and Atlantic cod was found. Copyright © 2015. Published by Elsevier B.V.

  13. Atlantic cod (Gadus morhua) hemoglobin genes: multiplicity and polymorphism

    Science.gov (United States)

    Borza, Tudor; Stone, Cynthia; Gamperl, A Kurt; Bowman, Sharen

    2009-01-01

    Background Hemoglobin (Hb) polymorphism, assessed by protein gel electrophoresis, has been used almost exclusively to characterize the genetic structure of Atlantic cod (Gadus morhua) populations and to establish correlations with phenotypic traits such as Hb oxygen binding capacity, temperature tolerance and growth characteristics. The genetic system used to explain the results of gel electrophoresis entails the presence of one polymorphic locus with two major alleles (HbI-1; HbI-2). However, vertebrates have more than one gene encoding Hbs and recent studies have reported that more than one Hb gene is present in Atlantic cod. These observations prompted us to re-evaluate the number of Hb genes expressed in Atlantic cod, and to perform an in depth search for polymorphisms that might produce relevant phenotypes for breeding programs. Results Analysis of Expressed Sequence Tags (ESTs) led to the identification of nine distinct Hb transcripts; four corresponding to the α Hb gene family and five to the β Hb gene family. To gain insights about the Hb genes encoding these transcripts, genomic sequence data was generated from heterozygous (HbI-1/2) parents and fifteen progeny; five of each HbI type, i.e., HbI-1/1, HbI-1/2 and HbI-2/2. β Hb genes displayed more polymorphism than α Hb genes. Two major allele types (β1A and β1B) that differ by two linked non-synonymous substitutions (Met55Val and Lys62Ala) were found in the β1 Hb gene, and the distribution of these β1A and β1B alleles among individuals was congruent with that of the HbI-1 and HbI-2 alleles determined by protein gel electrophoresis. RT-PCR and Q-PCR analysis of the nine Hb genes indicates that all genes are expressed in adult fish, but their level of expression varies greatly; higher expression of almost all Hb genes was found in individuals displaying the HbI-2/2 electrophoretic type. Conclusion This study indicates that more Hb genes are present and expressed in adult Atlantic cod than previously

  14. Atlantic cod (Gadus morhua hemoglobin genes: multiplicity and polymorphism

    Directory of Open Access Journals (Sweden)

    Gamperl A Kurt

    2009-09-01

    Full Text Available Abstract Background Hemoglobin (Hb polymorphism, assessed by protein gel electrophoresis, has been used almost exclusively to characterize the genetic structure of Atlantic cod (Gadus morhua populations and to establish correlations with phenotypic traits such as Hb oxygen binding capacity, temperature tolerance and growth characteristics. The genetic system used to explain the results of gel electrophoresis entails the presence of one polymorphic locus with two major alleles (HbI-1; HbI-2. However, vertebrates have more than one gene encoding Hbs and recent studies have reported that more than one Hb gene is present in Atlantic cod. These observations prompted us to re-evaluate the number of Hb genes expressed in Atlantic cod, and to perform an in depth search for polymorphisms that might produce relevant phenotypes for breeding programs. Results Analysis of Expressed Sequence Tags (ESTs led to the identification of nine distinct Hb transcripts; four corresponding to the α Hb gene family and five to the β Hb gene family. To gain insights about the Hb genes encoding these transcripts, genomic sequence data was generated from heterozygous (HbI-1/2 parents and fifteen progeny; five of each HbI type, i.e., HbI-1/1, HbI-1/2 and HbI-2/2. β Hb genes displayed more polymorphism than α Hb genes. Two major allele types (β1A and β1B that differ by two linked non-synonymous substitutions (Met55Val and Lys62Ala were found in the β1 Hb gene, and the distribution of these β1A and β1B alleles among individuals was congruent with that of the HbI-1 and HbI-2 alleles determined by protein gel electrophoresis. RT-PCR and Q-PCR analysis of the nine Hb genes indicates that all genes are expressed in adult fish, but their level of expression varies greatly; higher expression of almost all Hb genes was found in individuals displaying the HbI-2/2 electrophoretic type. Conclusion This study indicates that more Hb genes are present and expressed in adult

  15. Multidimensionality of behavioural phenotypes in Atlantic cod, Gadus morhua.

    Science.gov (United States)

    Meager, Justin J; Fernö, Anders; Skjæraasen, Jon Egil; Järvi, Torbjörn; Rodewald, Petra; Sverdrup, Gisle; Winberg, Svante; Mayer, Ian

    2012-06-25

    Much of the inter-individual variation observed in animal behaviour is now attributed to the existence of behavioural phenotypes or animal personalities. Such phenotypes may be fundamental to fisheries and aquaculture, yet there have been few detailed studies of this phenomenon in exploited marine animals. We investigated the behavioural and neuroendocrine responses of Atlantic cod (Gadus morhua L.), to situations reflecting critical ecological challenges: predator attacks and territorial challenges. Both hatchery-reared and wild fish were tested and behavioural profiles were compared with baseline conditions. We then used an objective, multivariate approach, rather than assigning individuals along one-dimensional behavioural axes, to examine whether distinct behavioural phenotypes were present. Our results indicate that two distinct behavioural phenotypes were evident in fish from each background. In hatchery-reared fish, phenotypes displayed divergent locomotor activity, sheltering, brain monoamine concentrations and responses to competitive challenges. In wild fish, phenotypes were distinguished primarily by locomotor activity, sheltering and responsiveness to predator stimuli. Hatcheries presumably represent a more stressful social environment, and social behaviour and neuroendocrine responses were important in discerning behavioural phenotypes in hatchery fish, whereas antipredator responses were important in discerning phenotypes in wild fish that have previously encountered predators. In both fish types, behavioural and physiological traits that classified individuals into phenotypes were not the same as those that were correlated across situations. These results highlight the multidimensionality of animal personalities, and that the processes that regulate one suite of behavioural traits may be very different to the processes that regulate other behaviours. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Genomic Sequencing of Ranaviruses Isolated from Turbot (Scophthalmus maximus) and Atlantic Cod (Gadus morhua).

    Science.gov (United States)

    Ariel, Ellen; Steckler, Natalie K; Subramaniam, Kuttichantran; Olesen, Niels J; Waltzek, Thomas B

    2016-12-15

    Ranaviruses have been isolated from Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus) in Denmark. Phylogenomic analyses revealed that these two ranaviruses are nearly identical and form a distinct clade at the base of the ranavirus tree branching off near other fish ranaviruses. Copyright © 2016 Ariel et al.

  17. Correlations between hemoglobin type and temperature preference of juvenile Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Gräns, Albin; Therkildsen, Nina Overgaard

    2012-01-01

    Atlantic cod (Gadus morhua L.) exhibits polymorphic hemoglobin variants with the HbI locus showing a strong North-South geographic cline in frequency distribution of three main types (1/1, 1/2 and 2/2). This may indicate selective advantages of the different HbI types under various temperature...

  18. Distribution and drift of Atlantic cod ( Gadus morhua ) eggs and larvae in Greenland offshore waters

    DEFF Research Database (Denmark)

    Wieland, Kai; Hovgård, Holger

    2002-01-01

    Catches of Atlantic cod (Gadus morhua) eggs and larvae from 45 national and international ichthyoplankton surveys conducted in Greenland offshore waters during the period 1950 to 1984 have been compiled and re-analysed. Southeast and Southwest Greenland were identified as im- portant spawning are...

  19. Genomic Sequencing of Ranaviruses Isolated from Turbot (Scophthalmus maximus) and Atlantic Cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Ariel, Ellen; Steckler, Natalie K.; Subramaniam, Kuttichantran

    2016-01-01

    Ranaviruses have been isolated from Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus) in Denmark. Phylogenomic analyses revealed that these two ranaviruses are nearly identical and form a distinct clade at the base of the ranavirus tree branching off near other fish ranaviruses....

  20. Immunological differences in intestine and rectum of Atlantic cod (Gadus morhua L.)

    NARCIS (Netherlands)

    Inami, M.; Taverne-Thiele, J.J.; Schroder, M.B.; Kiron, V.; Rombout, J.H.W.M.

    2009-01-01

    The defence system of the distal gut (hindgut and rectum) of Atlantic cod, (Gadus morhua L.) was studied using (immuno)histochemical, electron microscopical and real-time quantitative PCR techniques. The uptake and transport of macromolecules in the intestinal epithelium was also investigated. In

  1. Differential expression of immune and stress genes in the skin of Atlantic cod (Gadus morhua)

    NARCIS (Netherlands)

    Caipang, C.M.A.; Lazado, C.C.; Brinchmann, M.; Rombout, J.H.W.M.; Kiron, V.

    2011-01-01

    The present study describes the transcriptional profiles of selected immune and stress genes with putative important roles in the cutaneous immune defense of Atlantic cod (Gadus morhua). In addition it shows differential expression of many genes at the dorsal and ventral sides of fish, in general

  2. First record of brown colouration of Atlantic cod (Gadus morhua, L. from the North Sea

    Directory of Open Access Journals (Sweden)

    Agnieszka Rybczyk

    2014-01-01

    Full Text Available This paper reports the biological characterisation of a specimen of Atlantic cod (Gadus morhua L. with a unique brown colour, which is the first fish of this species with such a colouration recorded from European waters. It was caught in the coastal zone of the North Sea in June 2011. This ‘brown’ cod fish weighed 1074.3 g and had an overall length of 422 mm.

  3. Anesthesia induces stress in Atlantic salmon (Salmo salar), Atlantic cod (Gadus morhua) and Atlantic halibut (Hippoglossus hippoglossus).

    Science.gov (United States)

    Zahl, Inger Hilde; Kiessling, Anders; Samuelsen, Ole Bent; Olsen, Rolf Erik

    2010-09-01

    Stress in response to anesthesia with benzocaine, MS-222, metomidate and isoeugenol was studied in Atlantic salmon (Salmo salar), Atlantic halibut (Hippoglossus hippoglossus), and Atlantic cod (Gadus morhua) with no concomitant stress from handling or confinement in association with anesthesia or sampling. All of the anesthetics tested induced a stress response in all species, displayed by a release of cortisol to the water. MS-222 anesthesia elicited the highest cortisol release rates, reaching maximum levels 0.5 h post-exposure and returning to basal levels after 3-4 h. Benzocaine anesthesia caused a bimodal response where the initial peak in cortisol release rate was followed by a second increase lasting towards the end of the trial (6 h). This bimodality was more profound in Atlantic salmon than in Atlantic halibut and Atlantic cod. Metomidate anesthesia induced the lowest release of cortisol of the agents tested in both Atlantic halibut and Atlantic cod, but resulted in a bimodal response in Atlantic salmon where the initial increase in cortisol release was followed by a larger increase peaking at 2-2.5 h post exposure before returning to basal levels after 5 h. The stress induced in Atlantic salmon by isoeugenol anesthesia resembled that of MS-222, but did not reach the same elevated level. Overall, the cortisol release was most profound in Atlantic salmon followed by Atlantic halibut and Atlantic cod.

  4. Atlantic Cod (Gadus morhua benefits from the availability of seagrass (Zostera marina nursery habitat

    Directory of Open Access Journals (Sweden)

    Richard J. Lilley

    2014-12-01

    Full Text Available The Atlantic cod (Gadus morhua is a species of significant economic and historic importance but infamous for its decline. Apart from overfishing, the causes of this decline and its subsequent lack of recovery remain largely unresolved. Indeed, the degree to which specific habitats are important for this species remains unquantified at the scale of North Atlantic. Here, the literature on the role of eelgrass meadows (Zostera marina as valuable nursery habitat for the Atlantic cod is reviewed and synthesized. Evidence is presented on relative densities of Atlantic cod in shallow water environments and in eelgrass meadows in comparison to alternative habitats. In addition, evidence pertaining to the ’viability gains’ attributed to the use of eelgrass meadows as nursery habitat (growth and survival by juvenile Atlantic cod is analyzed. Although juvenile Atlantic cod use of Z. marina is found to be facultative, when possible, available literatures indicates that they may select Z. marina as a nursery habitat where they are found in high density (average of at least 246 ha−1. From their use of Z. marina habitat the juvenile Atlantic cod receives viability benefits from it, improving their chances of reaching maturation. This paper provides strong evidence that eelgrass meadows are of significant importance to contributing to Atlantic cod stocks.

  5. Gene expression profiling of Atlantic cod (Gadus morhua) embryogenesis using microarray.

    Science.gov (United States)

    Drivenes, Øyvind; Taranger, Geir Lasse; Edvardsen, Rolf B

    2012-04-01

    Atlantic cod (Gadus morhua) is a fish species of high importance, as a key species in a range of Northern ecosystems, in fisheries, and as an emerging species in aquaculture. So far, little is known about the transcriptional activity during early developmental stages of Atlantic cod. Hence, we decided to use a cDNA microarray covering 7,000 genes to analyze the temporal activity of the transcriptome during cod embryogenesis. Twelve different embryonic time points were selected, covering major developmental stages and processes such as maternally derived mRNA, blastula, gastrula, segmentation, hatching, and first-feeding larval stage. The microarray analysis revealed a highly dynamic transcriptional profile, showing for the first time the differential expression of thousands of known and unknown genes during Atlantic cod embryogenesis. These initial findings will serve as an important baseline for future in-depth studies of candidate genes involved in development, reproductive control, disease resistance, growth, nutrient digestion, and metabolism.

  6. Differences in salinity tolerance and gene expression between two populations of Atlantic cod (Gadus morhua) in response to salinity stress

    DEFF Research Database (Denmark)

    Larsen, Peter Foged; Eg Nielsen, Einar; Meier, Kristian

    2012-01-01

    in salinity tolerance and gene expression among Atlantic cod (Gadus morhua) from two populations distributed across a steep salinity gradient, we observed high mortality (45% North Sea cod and 80% Baltic Sea cod) in a reciprocal common garden setup. Quantitative RT-PCR assays for expression of hsp70 and Na....... The findings strongly suggest that Atlantic cod are adapted to local saline conditions, despite relatively low levels of neutral genetic divergence between populations...

  7. Male size composition affects male reproductive variance in Atlantic cod Gadus morhua L. spawning aggregations

    DEFF Research Database (Denmark)

    Bekkevold, Dorte

    2006-01-01

    Estimates of Atlantic cod Gadus morhua reproductive success, determined using experimental spawning groups and genetic paternity assignment of offspring, showed that within-group variance in male size correlated positively with the degree of male mating skew, predicting a decrease in male...... reproductive skew with decreasing size variation among males under natural conditions. (c) 2006 The Author Journal compilation (c) 2006 The Fisheries Society of the British Isles...

  8. Structure of chymotrypsin variant B from Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Asgeirsson, B; Thórólfsson, M

    1996-01-01

    The amino-acid sequence of chymotrypsin variant B isolated from the pyloric caeca of Atlantic cod has been elucidated. The characterization of the primary structure is based on N-terminal Edman degradation and mass spectrometry of the native protein and enzymatically derived peptides. Chymotrypsin...... variant B showed 72% sequence identity with the A-variant and 64% and 62%, respectively, with the bovine counterparts A and B, all consisting of 245 amino acids. This new sequence contains a higher proportion of charged residues compared with bovine chymotrypsin but fewer polar hydrogen-bond forming...... side-chains may contribute to the maintenance of flexibility at low temperatures. Several amino-acid sequence differences adjacent to the catalytic site are observed in the two cod chymotrypsin variants which also differ in kinetic properties. Unlike the mammalian chymotrypsins, which contain several...

  9. Mitochondrial acclimation potential to ocean acidification and warming of Polar cod (Boreogadus saida) and Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Leo, Elettra; Kunz, Kristina L; Schmidt, Matthias; Storch, Daniela; Pörtner, Hans-O; Mark, Felix C

    2017-01-01

    Ocean acidification and warming are happening fast in the Arctic but little is known about the effects of ocean acidification and warming on the physiological performance and survival of Arctic fish. In this study we investigated the metabolic background of performance through analyses of cardiac mitochondrial function in response to control and elevated water temperatures and PCO2 of two gadoid fish species, Polar cod (Boreogadus saida), an endemic Arctic species, and Atlantic cod (Gadus morhua), which is a temperate to cold eurytherm and currently expanding into Arctic waters in the wake of ocean warming. We studied their responses to the above-mentioned drivers and their acclimation potential through analysing the cardiac mitochondrial function in permeabilised cardiac muscle fibres after 4 months of incubation at different temperatures (Polar cod: 0, 3, 6, 8 °C and Atlantic cod: 3, 8, 12, 16 °C), combined with exposure to present (400μatm) and year 2100 (1170μatm) levels of CO2. OXPHOS, proton leak and ATP production efficiency in Polar cod were similar in the groups acclimated at 400μatm and 1170μatm of CO2, while incubation at 8 °C evoked increased proton leak resulting in decreased ATP production efficiency and decreased Complex IV capacity. In contrast, OXPHOS of Atlantic cod increased with temperature without compromising the ATP production efficiency, whereas the combination of high temperature and high PCO2 depressed OXPHOS and ATP production efficiency. Polar cod mitochondrial efficiency decreased at 8 °C while Atlantic cod mitochondria were more resilient to elevated temperature; however, this resilience was constrained by high PCO2. In line with its lower habitat temperature and higher degree of stenothermy, Polar cod has a lower acclimation potential to warming than Atlantic cod.

  10. Effect of petroleum aromatic hydrocarbons on monogeneids parasitizing Atlantic cod, Gadus morhua L

    Energy Technology Data Exchange (ETDEWEB)

    Khan, R.A.; Kiceniuk, J.W.

    1988-07-01

    Fish gills appear to be more susceptible than other tissues to toxicants. The latter include petroleum aromatic hydrocarbons, which can induce lesions characterized by excessive mucus secretion, hyperplasia, fusion of secondary gill lamellae and capillary dilation. Fish are also natural hosts to several species of ectoparasites, especially monogeneans which live among the gill filaments. A previous study on the interrelation of water quality, gill parasites and gill pathology provided evidence that fish living in habitats degraded by pollutants such as Biscayne Bay, Florida, were heavily infested with monogeneids especially when gill lesions were severe. Atlantic cod, Gadus morhua, are hosts to monogeneans. The authors reported previously that crude oil fractions induced gill lesions in cod and also affected some gastrointestinal parasites. In the light of these reports, a study was undertaken to ascertain whether any relationship existed between gill lesions and gill parasites in cod following chronic exposure to petroleum hydrocarbons.

  11. Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Therkildsen, Nina Overgaard; Hansen, Jakob Hemmer; Hedeholm, R.B.

    2013-01-01

    Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around...... increased temporal changes at a subset of loci also suggest that adaptation may be ongoing. These findings illustrate the power of spatiotemporal population genomics for revealing biocomplexity in both space and time and for informing future fisheries management and conservation efforts...

  12. Karyotyping and cytogenetic mapping of Atlantic cod (Gadus morhua Linnaeus, 1758).

    Science.gov (United States)

    Ghigliotti, L; Fevolden, S-E; Cheng, C-H C; Babiak, I; Dettai, A; Pisano, E

    2012-12-01

    The Atlantic cod (Gadus morhua) is an important natural resource for northern societies and is now also considered to be a promising candidate for aquaculture. In recent years, much effort has been directed towards the development of genomic tools, and genome initiatives for Atlantic cod have been established. Despite the growing attention devoted to the Atlantic cod genomics, basic aspects of its genome structure and organization remain unknown. Thus, the present work aims to study cytogenetic features of the Atlantic cod as a contribution to the knowledge of this species' genome. The Atlantic cod displays a diploid number of 46 chromosomes, with a karyotypic formula 16 m/sm + 30 st/t. Conventional karyotyping was improved by chromosomal mapping of two classes of repetitive sequences. 18S rDNA clusters were assigned to pairs 2 and 4; small amounts of 18S rDNA clusters were occasionally detected on pair 5. These findings could not be related to the geographical origin of the specimens, but were consistent with the variability of these repeated genes in fish in general. 5S ribosomal gene clusters, apparently corresponding to a single 5S rDNA class, were detected on twelve chromosomes (pairs 11, 12, 14, 17, 20 and 21). The present update of the existing but meagre information on the karyotype of Atlantic cod, plus the first physical mapping of repetitive genes in this species herein, opens the way for an integrated approach that combines genetic and physical mapping with the assembly of the genome of this commercially important species. © 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.

  13. Elucidation of different cold-adapted Atlantic cod (Gadus morhua) trypsin X isoenzymes.

    Science.gov (United States)

    Stefansson, Bjarki; Sandholt, Gunnar B; Gudmundsdottir, Ágústa

    2017-01-01

    Trypsins from Atlantic cod (Gadus morhua), consisting of several isoenzymes, are highly active cold-adapted serine proteases. These trypsins are isolated for biomedical use in an eco-friendly manner from underutilized seafood by-products. Our group has explored the biochemical properties of trypsins and their high potential in biomedicine. For broader utilization of cod trypsins, further characterization of biochemical properties of the individual cod trypsin isoenzymes is of importance. For that purpose, a benzamidine purified trypsin isolate from Atlantic cod was analyzed. Anion exchange chromatography revealed eight peaks containing proteins around 24kDa with tryptic activity. Based on mass spectrometric analysis, one isoenzyme gave the best match to cod trypsin I and six isoenzymes gave the best match to cod trypsin X. Amino terminal sequencing of two of these six trypsin isoenzymes showed identity to cod trypsin X. Three sequence variants of trypsin X were identified by cDNA analysis demonstrating that various forms of this enzyme exist. One trypsin X isoenzyme was selected for further characterization based on abundance and stability. Stepwise increase in catalytic efficiency (kcat/Km) of this trypsin X isoenzyme was obtained with substrates containing one to three amino acid residues. The study demonstrates that the catalytic efficiency of this trypsin X isoenzyme is comparable to that of cod trypsin I, the most abundant and highly active isoenzyme in the benzamidine cod trypsin isolate. Differences in pH stability and sensitivity to inhibitors of the trypsin X isoenzyme compared to cod trypsin I were detected that may be important for practical use. Copyright © 2016. Published by Elsevier B.V.

  14. Plastic ingestion by Atlantic cod (Gadus morhua) from the Norwegian coast.

    Science.gov (United States)

    Bråte, Inger Lise N; Eidsvoll, David P; Steindal, Calin Constantin; Thomas, Kevin V

    2016-11-15

    This study documents the occurrence of microplastic (20mm) in Atlantic cod (Gadus morhua), a common and economically important species of marine fish in Norway. Fish stomachs (n=302) were examined from six different locations along the coast of Norway. Three percent of the individual stomachs contained items identified by Fourier transform infrared spectroscopy (FTIR) as synthetic polymers. Bergen City Harbour was a hotspot with 27% of the cod examined found to contain plastic. Polyester was the most frequently detected polymer. All bar one of the stomachs that contained plastic were full of organic stomach content, suggesting a plastic gut clearance rate similar to the ingested food. It is proposed that stomach fullness is an important metric in order to avoid underestimations when assessing the levels of microplastic ingested by fish. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Ontogeny of redox regulation in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Hamre, Kristin; Penglase, Samuel J; Rasinger, Josef D; Skjærven, Kaja H; Olsvik, Pål A

    2014-08-01

    The reduction potential of a cell is related to its fate. Proliferating cells are more reduced than those that are differentiating, whereas apoptotic cells are generally the most oxidized. Glutathione is considered the most important cellular redox buffer and the average reduction potential (Eh) of a cell or organism can be calculated from the concentrations of glutathione (GSH) and glutathione disulfide (GSSG). In this study, triplicate groups of cod larvae at various stages of development (3 to 63 days post-hatch; dph) were sampled for analyses of GSSG/2GSH concentrations, together with activities of antioxidant enzymes and expression of genes encoding proteins involved in redox metabolism. The concentration of total GSH (GSH+GSSG) increased from 610 ± 100 to 1260 ± 150 μmol/kg between 7 and 14 dph and was then constant until 49 dph, after which it decreased to 810 ± 100 μmol/kg by 63 dph. The 14- to 49-dph period, when total GSH concentrations were stable, coincides with the proposed period of metamorphosis in cod larvae. The concentration of GSSG comprised approximately 1% of the total GSH concentration and was stable throughout the sampling series. This resulted in a decreasing Eh from -239 ± 1 to -262 ± 7 mV between 7 and 14 dph, after which it remained constant until 63 dph. The changes in GSH and Eh were accompanied by changes in the expression of several genes involved in redox balance and signaling, as well as changes in activities of antioxidant enzymes, with the most dynamic responses occurring in the early phase of cod larval development. It is hypothesized that metamorphosis in cod larvae starts with the onset of mosaic hyperplasia in the skeletal muscle at approximately 20 dph (6.8mm standard length (SL)) and ends with differentiation of the stomach and disappearance of the larval finfold at 40 to 50 dph (10-15 mm SL). Thus, metamorphosis in cod larvae seems to coincide with high and stable total concentrations of GSH. Copyright © 2014 The

  16. Influences of potential predictor variables on gastric evacuation in Atlantic cod Gadus morhua L. feeding on fish prey

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    2012-01-01

    The parameter values of a generic model of gastric evacuation were estimated from evacuation data on Atlantic cod Gadus morhua fed meals of four fish prey: herring Clupea harengus, sprat Sprattus sprattus, lesser sandeel Ammodytes tobianus and dab Limanda limanda. The effects on evacuation...

  17. Effects of Loma morhua (Microsporidia) infection on the cardiorespiratory performance of Atlantic cod Gadus morhua (L).

    Science.gov (United States)

    Powell, M D; Gamperl, A K

    2016-02-01

    The microsporidian Loma morhua infects Atlantic cod (Gadus morhua) in the wild and in culture and results in the formation of xenomas within the gill filaments, heart and spleen. Given the importance of the two former organs to metabolic capacity and thermal tolerance, the cardiorespiratory performance of cod with a naturally acquired infection of Loma was measured during an acute temperature increase (2 °C h(-1)) from 10 °C to the fish's critical thermal maximum (CT(Max)). In addition, oxygen consumption and swimming performance were measured during two successive critical swimming speed (U(crit)) tests at 10 °C. While Loma infection had a negative impact on cod cardiac function at warm temperatures, and on metabolic capacity in both the CT(Max) and U(crit) tests (i.e. a reduction of 30-40%), it appears that the Atlantic cod can largely compensate for these Loma-induced cardiorespiratory limitations. For example, (i) CT(Max) (21.0 ± 0.3 °C) and U(crit) (~1.75 BL s(-1)) were very comparable to those reported in previous studies using uninfected fish from the same founder population; and (ii) our data suggest that tissue oxygen extraction, and potentially the capacity for anaerobic metabolism, is enhanced in fish infected with this microsporidian. © 2015 The Authors Journal of Fish Diseases Published by John Wiley & Sons Ltd.

  18. Adaptation to Low Salinity Promotes Genomic Divergence in Atlantic Cod (Gadus morhua L.)

    Science.gov (United States)

    Berg, Paul R.; Jentoft, Sissel; Star, Bastiaan; Ring, Kristoffer H.; Knutsen, Halvor; Lien, Sigbjørn; Jakobsen, Kjetill S.; André, Carl

    2015-01-01

    How genomic selection enables species to adapt to divergent environments is a fundamental question in ecology and evolution. We investigated the genomic signatures of local adaptation in Atlantic cod (Gadus morhua L.) along a natural salinity gradient, ranging from 35‰ in the North Sea to 7‰ within the Baltic Sea. By utilizing a 12 K SNPchip, we simultaneously assessed neutral and adaptive genetic divergence across the Atlantic cod genome. Combining outlier analyses with a landscape genomic approach, we identified a set of directionally selected loci that are strongly correlated with habitat differences in salinity, oxygen, and temperature. Our results show that discrete regions within the Atlantic cod genome are subject to directional selection and associated with adaptation to the local environmental conditions in the Baltic- and the North Sea, indicating divergence hitchhiking and the presence of genomic islands of divergence. We report a suite of outlier single nucleotide polymorphisms within or closely located to genes associated with osmoregulation, as well as genes known to play important roles in the hydration and development of oocytes. These genes are likely to have key functions within a general osmoregulatory framework and are important for the survival of eggs and larvae, contributing to the buildup of reproductive isolation between the low-salinity adapted Baltic cod and the adjacent cod populations. Hence, our data suggest that adaptive responses to the environmental conditions in the Baltic Sea may contribute to a strong and effective reproductive barrier, and that Baltic cod can be viewed as an example of ongoing speciation. PMID:25994933

  19. Adaptation to Low Salinity Promotes Genomic Divergence in Atlantic Cod (Gadus morhua L.).

    Science.gov (United States)

    Berg, Paul R; Jentoft, Sissel; Star, Bastiaan; Ring, Kristoffer H; Knutsen, Halvor; Lien, Sigbjørn; Jakobsen, Kjetill S; André, Carl

    2015-05-20

    How genomic selection enables species to adapt to divergent environments is a fundamental question in ecology and evolution. We investigated the genomic signatures of local adaptation in Atlantic cod (Gadus morhua L.) along a natural salinity gradient, ranging from 35‰ in the North Sea to 7‰ within the Baltic Sea. By utilizing a 12 K SNPchip, we simultaneously assessed neutral and adaptive genetic divergence across the Atlantic cod genome. Combining outlier analyses with a landscape genomic approach, we identified a set of directionally selected loci that are strongly correlated with habitat differences in salinity, oxygen, and temperature. Our results show that discrete regions within the Atlantic cod genome are subject to directional selection and associated with adaptation to the local environmental conditions in the Baltic- and the North Sea, indicating divergence hitchhiking and the presence of genomic islands of divergence. We report a suite of outlier single nucleotide polymorphisms within or closely located to genes associated with osmoregulation, as well as genes known to play important roles in the hydration and development of oocytes. These genes are likely to have key functions within a general osmoregulatory framework and are important for the survival of eggs and larvae, contributing to the buildup of reproductive isolation between the low-salinity adapted Baltic cod and the adjacent cod populations. Hence, our data suggest that adaptive responses to the environmental conditions in the Baltic Sea may contribute to a strong and effective reproductive barrier, and that Baltic cod can be viewed as an example of ongoing speciation. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. Isolation and characterisation of two cDNAs encoding transglutaminase from Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Furnes, Clemens; Kileng, Øyvind; Jensen, Ingvill; Karki, Pralav; Eichacker, Lutz; Robertsen, Børre

    2014-01-01

    Two cDNAs encoding transglutaminase (TG) were identified in a subtractive cDNA library prepared from the head kidney of poly I:C stimulated Atlantic cod (Gadus morhua). Full-length TG-1 and TG-2 cDNA were cloned from the head kidney by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The deduced amino acid (aa) sequence for TG-1 was 695 aa with an estimated molecular mass of 78.3 kDa, while TG-2 was a 698 aa protein with an estimated molecular mass of 78.8 kDa. The two proteins were named TG-1 and TG-2 and both possess transglutaminase/protease-like homologous domains (TGc) and full conservation of amino acids cysteine, histidine, and aspartate residues that form the catalytic triad. Sequence analysis showed high similarity (93.1%) with Alaska pollock TG, and the TGs were grouped together with TGs from chum salmon, Japanese flounder, Nile tilapia, and red sea bream in addition to Alaska pollock in phylogenetic analysis. Interestingly, they showed different tissue distribution with highest constitutive expression in reproductive and immunological organs, indicating important roles in these organs. Furthermore, the up-regulation of TG-1 and TG-2 in head kidney after stimulating Atlantic cod with poly I:C suggested a role of TGs in immune response in Atlantic cod. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Induction of meiotic gynogenesis in Atlantic cod (Gadus morhua L.) through pressure shock.

    Science.gov (United States)

    Ghigliotti, Laura; Bolla, Sylvie L; Duc, Michal; Ottesen, Oddvar H; Babiak, Igor

    2011-08-01

    The Atlantic cod, Gadus morhua, is one of the most important species for commercial fisheries and a promising candidate for aquaculture. Precocious sexual maturation of males is one of the major issues compromising large scale production. The potential approaches to this problem include production of all female populations. Consequently, the objective of this study was to develop an effective protocol to induce meiotic gynogenesis in the Atlantic cod by using hydrostatic pressure shock. Our first experiment tested the relevance of gamete quality on achievement of chromosome manipulation and identified the best time interval between fertilization and pressure shock. Our second experiment was designed to determine the optimal pressure value and duration of the pressure shock. Eight combinations of pressure values and durations were tested. Among them, the 34.47 MPa/6 min combination gave the best survival rate (23.6 ± 3.9%), the highest percentage of normal larvae (15.7 ± 3.6%), and the highest percentage of meiotic diploids (88.89%). In both experiments, haploid controls served as an indirect reference for paternal DNA inactivation. Chromosome counting confirmed the restoration of diploidy in gynogenetic fish. The present study optimizes a procedure for the induction of meiotic gynogenesis in the Atlantic cod, thus laying the basis for further applications towards producing monosex and defining the sex determination system. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Conserving marine biodiversity: insights from life-history trait candidate genes in Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Hansen, Jakob Hemmer; Therkildsen, Nina Overgaard; Meldrup, Dorte

    2014-01-01

    Recent technological developments have facilitated an increased focus on identifying genomic regions underlying adaptive trait variation in natural populations, and it has been advocated that this information should be important for designating population units for conservation. In marine fishes......, phenotypic studies have suggested adaptation through divergence of life-history traits among natural populations, but the distribution of adaptive genetic variation in these species is still relatively poorly known. In this study, we extract information about the geographical distribution of genetic...... variation for 33 single nucleotide polymorphisms (SNPs) associated with life-history trait candidate genes, and compare this to variation in 70 putatively neutral SNPs in Atlantic cod (Gadus morhua). We analyse samples covering the major population complexes in the eastern Atlantic and find strong evidence...

  3. Effects of ocean acidification on the calcification of otoliths of larval Atlantic cod, Gadus morhua L.

    Science.gov (United States)

    Maneja, R. H.; Frommel, A. Y.; Geffen, A. J.; Folkvord, A.; Piatkowski, U.; Chang, M. Y.; Clemmesen, C.

    2012-04-01

    The aragonitic calcium carbonate composition of the otoliths of teleost fishes could bring the organism in direct risk to ocean acidification. The potential effects of increase in atmospheric CO2 on the calcification of the otoliths were investigated by rearing Atlantic cod larvae (Gadus morhua L.) in three pCO2 concentrations, control-370, medium-1800, and high-4200 ppm from March to May 2010. Hypercalcification of otoliths were observed from 7 to 46-dph cod larvae cultured at elevated pCO2 concentrations. The sagittae and lapilli were largest at the high pCO2 treatment followed by medium and control with the biggest difference (83.8%) in mean otolith (sagitta) surface area at 32-dph between the high and control groups. The shift in the growth rates of the sagittae and lapilli also occurred much earlier in the high treatment with the growth of the sagitta surpassing that of the lapillus already at 32-dph. On the other hand, Atlantic cod larvae showed no trends in fluctuating asymmetry of the otoliths vis-a-vis the increase in otolith growth from elevated pCO2.

  4. Influence of climatic changes on the parasites of Atlantic cod Gadus morhua off coastal Labrador, Canada.

    Science.gov (United States)

    Khan, R A; Chandra, C V

    2006-06-01

    A study was conducted in 2000 and 2003, following the collapse of the commercial fishery in 1990, to compare metazoan parasites of Atlantic cod Gadus morhua, captured off coastal Labrador, with samples taken in 1980 and 1986. Fish were captured by otter trawl offshore in the North Atlantic Fish Organisation subarea 2J. Parasites were removed from the digestive tract, stained, identified and compared between the different groups. Both the prevalence and mean abundance of trematodes, larval nematodes and E. gadi were significantly lower in fish taken in 2000 and 2003 than in 1980. While mean values of trematodes and nematodes declined in 1986, those of Echinorhynchus gadi remained unchanged in 1986 and 1990. Four-year-old cod sampled in 1990 harboured significantly fewer E. gadi than older age groups. The most commonly occurring trematodes included Podocotyle reflexa, Lepidapedon elongatum, Derogenes varicus and Hemiurus levinseni while the larval nematode, Anisakis sp. was predominant. Comparison of offshore samples taken in 2000 and 2003 with others taken in previous years suggests an overall decline of parasites coincident with a change in climatic conditions, the absence of a major food source, namely capelin Mallotus villosus, of cod and ultimately the decline of the Labrador population.

  5. Factors regulating early life history dispersal of Atlantic cod (Gadus morhua from coastal Newfoundland.

    Directory of Open Access Journals (Sweden)

    Ryan R E Stanley

    Full Text Available To understand coastal dispersal dynamics of Atlantic cod (Gadus morhua, we examined spatiotemporal egg and larval abundance patterns in coastal Newfoundland. In recent decades, Smith Sound, Trinity Bay has supported the largest known overwintering spawning aggregation of Atlantic cod in the region. We estimated spawning and dispersal characteristics for the Smith Sound-Trinity Bay system by fitting ichthyoplankton abundance data to environmentally-driven, simplified box models. Results show protracted spawning, with sharply increased egg production in early July, and limited dispersal from the Sound. The model for the entire spawning season indicates egg export from Smith Sound is 13%•day(-1 with a net mortality of 27%•day(-1. Eggs and larvae are consistently found in western Trinity Bay with little advection from the system. These patterns mirror particle tracking models that suggest residence times of 10-20 days, and circulation models indicating local gyres in Trinity Bay that act in concert with upwelling dynamics to retain eggs and larvae. Our results are among the first quantitative dispersal estimates from Smith Sound, linking this spawning stock to the adjacent coastal waters. These results illustrate the biophysical interplay regulating dispersal and connectivity originating from inshore spawning of coastal northwest Atlantic.

  6. Factors Regulating Early Life History Dispersal of Atlantic Cod (Gadus morhua) from Coastal Newfoundland

    Science.gov (United States)

    Stanley, Ryan R. E.; deYoung, Brad; Snelgrove, Paul V. R.; Gregory, Robert S.

    2013-01-01

    To understand coastal dispersal dynamics of Atlantic cod (Gadus morhua), we examined spatiotemporal egg and larval abundance patterns in coastal Newfoundland. In recent decades, Smith Sound, Trinity Bay has supported the largest known overwintering spawning aggregation of Atlantic cod in the region. We estimated spawning and dispersal characteristics for the Smith Sound-Trinity Bay system by fitting ichthyoplankton abundance data to environmentally-driven, simplified box models. Results show protracted spawning, with sharply increased egg production in early July, and limited dispersal from the Sound. The model for the entire spawning season indicates egg export from Smith Sound is 13%•day−1 with a net mortality of 27%•day–1. Eggs and larvae are consistently found in western Trinity Bay with little advection from the system. These patterns mirror particle tracking models that suggest residence times of 10–20 days, and circulation models indicating local gyres in Trinity Bay that act in concert with upwelling dynamics to retain eggs and larvae. Our results are among the first quantitative dispersal estimates from Smith Sound, linking this spawning stock to the adjacent coastal waters. These results illustrate the biophysical interplay regulating dispersal and connectivity originating from inshore spawning of coastal northwest Atlantic. PMID:24058707

  7. Highly localized divergence within supergenes in Atlantic cod (Gadus morhua) within the Gulf of Maine.

    Science.gov (United States)

    Barney, Bryan T; Munkholm, Christiane; Walt, David R; Palumbi, Stephen R

    2017-03-31

    Atlantic cod (Gadus morhua), is known to vary genetically across the North Atlantic, Greenland, and Newfoundland. This genetic variation occurs both spatially and temporally through decades of heavy fishing, and is concentrated in three linkage disequilibrium blocks, previously defined by pedigreed linkage mapping analysis. Variation within these genomic regions is correlated with both seawater temperature and behavioral ecotype. The full extent and nature of these linkage groups is important information for interpreting cod genetic structure as a tool for future fisheries management. We conducted whole genome sequencing for 31 individual cod from three sub-populations in the Gulf of Maine. Across the genome, we found 3,390,654 intermediate to high frequency Single Nucleotide Polymorphisms (SNPs). We show that pairwise linkage analysis among these SNPs is a powerful tool to detect linkage disequilibrium clusters by recovering the three previously detected linkage groups and identifying the 1031 genes contained therein. Across these genes, we found significant population differentiation among spawning groups in the Gulf of Maine and between Georges Bank and Gulf of Maine. Coordinated divergence among these genes and their differentiation at both short and long spatial scales suggests that they are acting as linked supergenes in local adaptation of cod populations. Differentiation between SNPs in linkage disequilibrium blocks is the major signal of genetic differentiation between all groups tested within the Gulf of Maine. Our data provide a map of genes contained in these blocks, allowing an enhanced search for neutral genetic structure for demographic inference and fisheries modeling. Patterns of selection and the history of populations may be possible to identify in cod using this description of linkage disequilibrium blocks and future data sets to robustly separate neutral and selected genetic markers.

  8. Prey exoskeletons influence the course of gastric evacuation in Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Couturier, C. S.; Andersen, N. G.; Audet, C.

    2013-01-01

    This study examined the effects of prey exoskeleton characteristics on gastric evacuation patterns in Atlantic cod Gadus morhua. Three distinct stages were highlighted in the gastric evacuation of crustacean prey characterized by a robust exoskeleton. The experiments confirmed that the three shrimp...... of the prey exoskeleton all affected gastric evacuation: duration of initial delay, overall evacuation rate and a decreased evacuation rate at the end of the process. The power exponential function (PEF), with its shape parameter, described the course of evacuation for these prey types well, especially...... the initial delay. The PEF does not, however, allow describing evacuation by the current stomach content mass independent of meal size, which limits its usefulness in estimating consumption rates of wild G. morhua. To predict and describe gastric evacuation of prey with a robust exoskeleton, it is therefore...

  9. Fathers modify thermal reaction norms for hatching success in Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Dahlke, Flemming T.; Politis, Sebastian Nikitas; Butts, Ian

    2016-01-01

    Climate-driven warming is altering marine ecosystems at an unprecedented rate and evolutionary adaptation may represent the last resort for many ectothermic organisms to avoid local extinction. The first step to elucidate the potential for adaptation to unfavorable thermal conditions is to assess...... therefore hold important implications for resilience. This study examined how males differ in their ability to sire viable offspring and whether the paternal contribution modified thermal reaction norms for hatching success in two replicated trials with cod Gadus morhua from the Northwest Atlantic (trial 1...... hatching success significantly decreased towards thermal extremes. However, half-sibling families varied in their response to different incubation temperatures as indicated by significant paternity × temperature interactions and crossing of reaction norms. The influence of paternity itself was highly...

  10. Inter-population ovarian fluid variation differentially modulates sperm motility in Atlantic cod Gadus morhua.

    Science.gov (United States)

    Beirão, J; Purchase, C F; Wringe, B F; Fleming, I A

    2015-07-01

    This study tested the hypothesis that the effects of Atlantic cod Gadus morhua ovarian fluid on sperm motility variables are population specific. Sperm from a northern G. morhua population were activated in the presence of ovarian fluid from either northern or southern G. morhua at different concentrations. Ovarian fluid acted as a filter, in some cases reducing sperm swimming performance compared with seawater. Fluid from females foreign in population (southern) to the males (northern) had a greater inhibiting effect than those from the native population. Follow-up analysis indicated that the ovarian fluids had lower Ca(2+) concentration in northern than southern G. morhua, which could be the causative mechanism. If widespread, such cryptic female choice could reduce the incidence of intraspecific hybridization among diverged populations and contribute to reproductive isolation. © 2015 The Fisheries Society of the British Isles.

  11. Paternal effects on early life history traits in Northwest Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Kroll, M.-M.; Peck, M.A.; Butts, Ian A.E.

    2013-01-01

    and survival. In marine fish, rates of natural mortality are highest during early life and are negatively correlated with rates of growth and body size. In these early life stages (eggs, larvae, young juveniles) subtle differences in mortality can cause large differences in recruitment and year-class success....... Therefore, it is particularly critical to understand factors that contribute to variability in mortality during early life. This study focuses on evaluating the potential influence of paternity on rates of mortality and development in eggs and larvae of Northwest Atlantic cod, Gadus morhua. To accomplish...... this 12 males and two females were crossed using a full-factorial breeding design. Paternity had a strong influence on fertilization success, hatching success, cumulative embryonic mortality, larval standard length, eye diameter, yolk-sac area, and cumulative larval mortality. Female 1 showed an overall...

  12. Diet affects the redox system in developing Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Penglase, Samuel; Edvardsen, Rolf B; Furmanek, Tomasz; Rønnestad, Ivar; Karlsen, Ørjan; van der Meeren, Terje; Hamre, Kristin

    2015-08-01

    The growth and development of marine fish larvae fed copepods is superior to those fed rotifers, but the underlying molecular reasons for this are unclear. In the following study we compared the effects of such diets on redox regulation pathways during development of Atlantic cod (Gadus morhua) larvae. Cod larvae were fed a control diet of copepods or the typical rotifer/Artemia diet commonly used in commercial marine fish hatcheries, from first feeding until after metamorphosis. The oxidised and reduced glutathione levels, the redox potential, and the mRNA expression of 100 genes in redox system pathways were then compared between treatments during larval development. We found that rotifer/Artemia-fed cod larvae had lower levels of oxidised glutathione, a more reduced redox potential, and altered expression of approximately half of the redox system genes when compared to copepod-fed larvae. This rotifer/Artemia diet-induced differential regulation of the redox system was greatest during periods of suboptimal growth. Upregulation of the oxidative stress response transcription factor, nrf2, and NRF2 target genes in rotifer/Artemia fed larvae suggest this diet induced an NRF2-mediated oxidative stress response. Overall, the data demonstrate that nutritional intake plays a role in regulating the redox system in developing fish larvae. This may be a factor in dietary-induced differences observed in larval growth. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Diet affects the redox system in developing Atlantic cod (Gadus morhua larvae

    Directory of Open Access Journals (Sweden)

    Samuel Penglase

    2015-08-01

    Full Text Available The growth and development of marine fish larvae fed copepods is superior to those fed rotifers, but the underlying molecular reasons for this are unclear. In the following study we compared the effects of such diets on redox regulation pathways during development of Atlantic cod (Gadus morhua larvae. Cod larvae were fed a control diet of copepods or the typical rotifer/Artemia diet commonly used in commercial marine fish hatcheries, from first feeding until after metamorphosis. The oxidised and reduced glutathione levels, the redox potential, and the mRNA expression of 100 genes in redox system pathways were then compared between treatments during larval development. We found that rotifer/Artemia-fed cod larvae had lower levels of oxidised glutathione, a more reduced redox potential, and altered expression of approximately half of the redox system genes when compared to copepod-fed larvae. This rotifer/Artemia diet-induced differential regulation of the redox system was greatest during periods of suboptimal growth. Upregulation of the oxidative stress response transcription factor, nrf2, and NRF2 target genes in rotifer/Artemia fed larvae suggest this diet induced an NRF2-mediated oxidative stress response. Overall, the data demonstrate that nutritional intake plays a role in regulating the redox system in developing fish larvae. This may be a factor in dietary-induced differences observed in larval growth.

  14. Characterizing ovarian gene expression during oocyte growth in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Breton, Timothy S; Berlinsky, David L

    2014-03-01

    Vertebrate oocytes undergo dramatic changes during development as they accumulate many RNA transcripts, glycoproteins, and yolk proteins, necessary to ensure proper fertilization and embryogenesis. Oogenesis in teleosts often requires several years for completion, but very little is known about the early developmental stages. Recently, two-stage gene expression comparisons were made during oocyte growth in coho salmon (Oncorhynchus kisutch) and Atlantic cod (Gadus morhua), but more broad-scale, comprehensive assessments have not been conducted. The objectives of the present study were to characterize the gene expression patterns throughout oocyte growth in cod and compare them to changes previously identified in coho salmon. A quantitative PCR survey was conducted using 50 genes at six ovarian stages, ranging from the onset of primary growth (oocyte differentiation) to late vitellogenesis. Most expression patterns could be grouped into three major clusters, consisting of oocyte-derived (cluster 1) and likely follicle cell (clusters 2 and 3) genes. Oocyte genes were elevated during primary growth, while many follicle cell transcripts were abundant during oocyte differentiation and vitellogenesis. Few expression changes identified in coho salmon were evident in cod, which is likely due to differences in reproductive strategies. These results demonstrate that dynamic changes in gene expression occur during oocyte growth in teleost fish. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Effects of dietary arachidonic acid on the reproductive physiology of female Atlantic cod (Gadus morhua L.).

    Science.gov (United States)

    Norberg, Birgitta; Kleppe, Lene; Andersson, Eva; Thorsen, Anders; Rosenlund, Grethe; Hamre, Kristin

    2017-09-01

    The present study was designed to investigate potential effects of arachidonic acid (ARA) on the reproductive physiology of female Atlantic cod (Gadus morhua L.). Two-year old Atlantic cod of both sexes were equally distributed into eight sea cages after completion of their first spawning in May 2005. Four experimental groups were established and fed diets with different levels of ARA corresponding to 0.5, 1, 2 and 4% of total fatty acid. Ovarian growth and development was documented every month. Fatty acid composition was analysed in ovaries, liver and plasma at the beginning of the experiment, one month prior to spawning, and in spent fish, one month after spawning was completed. Plasma concentrations of estradiol-17β, testosterone and vitellogenin, and ovarian gene transcript levels of steroidogenic acute regulatory protein (star), P450aromatase (cyp19a1a) and 20β-hydroxy steroid dehydrogenase (20bhsd/cbr1) were monitored every month in fish fed the experimental diets and related to oocyte stage. Potential fecundity was calculated based on ovarian samples taken one month before onset of spawning. Ovarian and plasma ARA levels were highly correlated to dietary ARA levels. There was a net accumulation of ARA compared to other essential fatty acids in ovarian tissue that was reflected in a decrease in EPA:ARA ratio. Plasma concentrations of vitellogenin, estradiol-17β and testosterone and key gene transcript levels were affected by dietary ARA and stage of maturation. The results show that ARA has a significant influence on the reproductive physiology of female Atlantic cod. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. An estrogen-responsive plasma protein expression signature in Atlantic cod (Gadus morhua) revealed by SELDI-TOF MS

    DEFF Research Database (Denmark)

    Nielsen, Mari Mæland; Meyer, Sonnich; Larsen, Bodil Katrine

    2011-01-01

    an estrogen-responsive PES in plasma of Atlantic cod (Gadus morhua) using the SELDI-TOF MS technique. Protein expression analysis of male cod exposed to 17 b-estradiol (E2) showed that 27 plasma peaks were differentially expressed following exposure.There producibility of this result was evaluated...... by reanalyzing the samples six months later,and a significant change in expression was confirmed for 13 of the 27 peaks detected in the first analysis. The performance of the reproducible E2-responsive PES, constituting these 13 peaks, was then tested on samples from juvenile cod exposed to 4-nonylphenol, North...... Sea oil, or North Sea oil spiked with alkylphenols. Principal component analysis revealed that nonylphenol-exposed cod could be separated from unexposed cod based on the E2-responsive PES, indicating that the PES can be used to assess estrogenic exposure of both juvenile and adult specimens of cod...

  17. Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua

    Science.gov (United States)

    Therkildsen, Nina Overgaard; Hemmer-Hansen, Jakob; Hedeholm, Rasmus Berg; Wisz, Mary S; Pampoulie, Christophe; Meldrup, Dorte; Bonanomi, Sara; Retzel, Anja; Olsen, Steffen Malskær; Nielsen, Einar Eg

    2013-01-01

    Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around Greenland, but the dynamics of earlier abundance fluctuations are not well understood. We applied a retrospective spatiotemporal population genomics approach to examine the temporal stability of cod population structure in this region and to search for signatures of divergent selection over a 78-year period spanning major demographic changes. Analyzing >900 gene-associated single nucleotide polymorphisms in 847 individuals, we identified four genetically distinct groups that exhibited varying spatial distributions with considerable overlap and mixture. The genetic composition had remained stable over decades at some spawning grounds, whereas complete population replacement was evident at others. Observations of elevated differentiation in certain genomic regions are consistent with adaptive divergence between the groups, indicating that they may respond differently to environmental variation. Significantly increased temporal changes at a subset of loci also suggest that adaptation may be ongoing. These findings illustrate the power of spatiotemporal population genomics for revealing biocomplexity in both space and time and for informing future fisheries management and conservation efforts. PMID:23789034

  18. Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua.

    Science.gov (United States)

    Therkildsen, Nina Overgaard; Hemmer-Hansen, Jakob; Hedeholm, Rasmus Berg; Wisz, Mary S; Pampoulie, Christophe; Meldrup, Dorte; Bonanomi, Sara; Retzel, Anja; Olsen, Steffen Malskær; Nielsen, Einar Eg

    2013-06-01

    Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around Greenland, but the dynamics of earlier abundance fluctuations are not well understood. We applied a retrospective spatiotemporal population genomics approach to examine the temporal stability of cod population structure in this region and to search for signatures of divergent selection over a 78-year period spanning major demographic changes. Analyzing >900 gene-associated single nucleotide polymorphisms in 847 individuals, we identified four genetically distinct groups that exhibited varying spatial distributions with considerable overlap and mixture. The genetic composition had remained stable over decades at some spawning grounds, whereas complete population replacement was evident at others. Observations of elevated differentiation in certain genomic regions are consistent with adaptive divergence between the groups, indicating that they may respond differently to environmental variation. Significantly increased temporal changes at a subset of loci also suggest that adaptation may be ongoing. These findings illustrate the power of spatiotemporal population genomics for revealing biocomplexity in both space and time and for informing future fisheries management and conservation efforts.

  19. The influence of feeding behaviour on growth of Atlantic cod (Gadus morhua, Linnaeus, 1758) in the North Sea

    DEFF Research Database (Denmark)

    Hüssy, Karin; Andersen, Niels Gerner; Pedersen, Eva Maria

    2016-01-01

    The objective of this study was to resolve key mechanisms driving individual growth patterns of Atlantic cod (Gadus morhua). Growth dynamics were analysed by linking growth patterns with stomach content composition and environmental temperature. Samples were collected in August/September of the y......The objective of this study was to resolve key mechanisms driving individual growth patterns of Atlantic cod (Gadus morhua). Growth dynamics were analysed by linking growth patterns with stomach content composition and environmental temperature. Samples were collected in August......% by mass), of which six were used for growth analyses: “Sandeel”, “Clupeids”, “Norway pout”, “Flatfishes”, “Crustaceans” and “Brittle stars”. For each group, growth patterns were estimated based on measures of otolith growth increments. The stomach contents showed that cod as a species are opportunistic...... decreased with increasing cod size, whereas that of fish and predominantly herring increased. Prey type had a significant effect on growth, while temperature had no effect. Slowest growth was observed in the cod group preying on sandeel, while cod preying on Norway pout showed the fastest growth...

  20. The Effects of Temperature, Hypoxia and Hypercapnia on the Metabolism of Atlantic Cod Gadus morhua

    DEFF Research Database (Denmark)

    Tirsgård, Bjørn

    showed that RMRlow and RMRhigh increased with age, by scaling exponents ranging between 0.58 and 0.87 at the three temperature tested. In periods with low prey availability a low water temperature and body size increase the survival rate whereas high water temperatures enhance growth rate when prey......The Atlantic cod (Gadus morhua L. 1758) is an important species both as a major top predator in the ecosystem and economical marine resource in the fishing industry of Northern Europe (Andersen, 2012). As an ectothermic water breather the Atlantic cod is continuously exposed to annual changes...... in the water conditions affecting their performance, growth and reproduction. Variations in the water conditions between years and due to climatic changes, affects the survival rate, population dynamic and bio-energetic distribution of the Atlantic cod (Hansson et al., 1996; Essington et al., 2001...

  1. Low plastic ingestion rate in Atlantic cod (Gadus morhua) from Newfoundland destined for human consumption collected through citizen science methods.

    Science.gov (United States)

    Liboiron, Max; Liboiron, France; Wells, Emily; Richárd, Natalie; Zahara, Alexander; Mather, Charles; Bradshaw, Hillary; Murichi, Judyannet

    2016-12-15

    Marine microplastics are a contaminant of concern because their small size allows ingestion by a wide range of marine life. Using citizen science during the Newfoundland recreational cod fishery, we sampled 205 Atlantic cod (Gadus morhua) destined for human consumption and found that 5 had eaten plastic, an ingestion prevalence rate of 2.4%. This ingestion rate for Atlantic cod is the second lowest recorded rate in the reviewed published literature (the lowest is 1.4%), and the lowest for any fish in the North Atlantic. This is the first report for plastic ingestion in fish in Newfoundland, Canada, a province dependent on fish for sustenance and livelihoods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. A new method for the rapid detection of Atlantic cod (Gadus morhua), Pacific cod (Gadus macrocephalus), Alaska pollock (Gadus chalcogrammus) and ling (Molva molva) using a lateral flow dipstick assay.

    Science.gov (United States)

    Taboada, Ledicia; Sánchez, Ana; Pérez-Martín, Ricardo I; Sotelo, Carmen G

    2017-10-15

    Species-specific lateral flow dipstick (LFD) assays for the identification of Atlantic cod (Gadus morhua), Pacific cod (Gadus macrocephalus), Alaska pollock (Gadus chalcogrammus) and ling (Molva molva) in food products were developed. The method comprises a PCR system with four sets of specific primers, for each target species. This step was also devised to dual-labeling of PCR products with biotin and 6-FAM, which are then easily read on a lateral flow dipstick, upon which these products are immobilized by a fixed biotin-ligand and visualized with anti-FAM antibody-coated gold nanoparticles. Sensitivity and selectivity were determined for each of the developed assays. Validation of the assays was performed with DNA extracted from commercial fish products, the identification of all samples by PCR-LFD was coherent with the results found with DNA sequencing. Target species were successfully detected in analyzed commercial samples, demonstrating the applicability of this method to the rapid analysis of food products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Accumulation and elimination of methylmercury in Atlantic cod (Gadus morhua L.) following dietary exposure

    Energy Technology Data Exchange (ETDEWEB)

    Amlund, Heidi [National Institute of Nutrition and Seafood Research (NIFES), P.O. Box 2029 Nordnes, 5817 Bergen (Norway)]. E-mail: heidi.amlund@nifes.no; Lundebye, Anne-Katrine [National Institute of Nutrition and Seafood Research (NIFES), P.O. Box 2029 Nordnes, 5817 Bergen (Norway); Berntssen, Marc H.G. [National Institute of Nutrition and Seafood Research (NIFES), P.O. Box 2029 Nordnes, 5817 Bergen (Norway)

    2007-08-01

    Methylmercury is known to bioaccumulate and biomagnify up the marine food chain. Fish from high levels of the marine food chain may contain relatively high concentrations of mercury, and most (>70%) of the mercury found in muscle is methylmercury. In aquaculture, marine protein (mainly fishmeal) is the dominant source of methylmercury, and this raises some concern with regards to fish welfare and consumer safety. A dietary exposure study, including a depuration period, was carried out in order to study the accumulation and elimination of methylmercury in Atlantic cod (Gadus morhua L.), and to estimate the transfer of methylmercury from feed to fish. Fish were sampled throughout a three month exposure period and a three month depuration period. Muscle samples were fractionated into a protein and a lipid fraction by lipid extraction using methanol and chloroform. Mercury and methylmercury were determined by inductively coupled plasma mass spectrometry (ICPMS) and gas chromatography-inductively coupled plasma mass spectrometry (GC-ICPMS), respectively. A continuous accumulation of methylmercury, after a lag period of 10 days, was observed in muscle tissue during the three months exposure to methylmercury (0.95+/-0.03{mu}g Hg/g feed, n=6). After three months, the final concentration in muscle was 0.38+/-0.04{mu}g Hg/gww (n=6), where methylmercury constituted 90-95% of the mercury present. The elimination of methylmercury from muscle was slow and incomplete (within the three months of depuration) with an estimated elimination half-life (t{sub 1/2}) of 377 days. The transfer of methylmercury from feed to Atlantic cod, described by the estimated absorption efficiency, was 38%. In muscle more than 99% of the mercury was found in the protein fraction. These results suggest that Atlantic cod readily takes up dietary methylmercury, which is efficiently accumulated into muscle, where it is incorporated into larger peptides or proteins. Comparable results were found for

  4. Distinction among North Atlantic cod Gadus morhua stocks by tissue fatty acid profiles.

    Science.gov (United States)

    Joensen, H; Grahl-Nielsen, O

    2014-06-01

    The fatty acid (FA) profiles of the white muscle and heart tissues of cod Gadus morhua from five locations, Faroe Bank, Faroe Plateau, North-West Iceland, Norway-Barents Sea and Denmark-Skagerrak, were population dependent. The interregional differences of FAs were significantly dissimilar (P Fisheries Society of the British Isles.

  5. Pre-anaesthetic metomidate sedation delays the stress response after caudal artery cannulation in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Karlsson, Anders; Rosseland, Bjørn Olav; Massabuau, Jean-Charles; Kiessling, Anders

    2012-04-01

    Recovery from caudal artery cannulation with and without pre-anaesthesia metomidate sedation was assessed in Atlantic cod (Gadus morhua). The levels of plasma cortisol, glucose, electrolytes and acid-base parameters were compared between sedated and unsedated cod and to those in uncannulated individuals, where the samples were obtained by sacrificial sampling (reference level). Metomidate sedation delayed the stress response, causing sedated cod plasma cortisol to return to the reference level more slowly [day 4 post surgery (PS)] than in unsedated cod (day 2 PS). Plasma glucose was elevated in both sedated and unsedated cod up to and including day 5 PS. Plasma K(+) was lower and pH was higher in cannulated cod than in the reference from 24 h PS until the end of experimentation, indicating a stress effect of sacrificial sampling on plasma K(+) and pH that was likely caused by an acute stress response. Metomidate sedation delayed the stress response following CA cannulation and should therefore not be used as a pre-anaesthetic sedation in Atlantic cod. The caudal artery cannulation can be a useful tool in obtaining repeated blood samples from Atlantic cod given an adequate recovery time, which was determined to be 6 days irrespective of pre-anaesthesia sedation status.

  6. Expression of vasa and nanos3 during primordial germ cell formation and migration in Atlantic cod (Gadus morhua L.).

    Science.gov (United States)

    Presslauer, C; Nagasawa, K; Fernandes, J M O; Babiak, I

    2012-10-01

    Primordial germ cells (PGCs), progenitors of gametes, are specified very early in embryonic development and undergo an active migration to the site where the future gonads will form. While the developmental pattern of PGCs during embryogenesis has been documented in few model teleost fishes, there is currently no information available for any representative of Superorder Paracanthopterygii. This includes Atlantic cod (Gadus morhua), which is a historically important food fish in both fisheries and aquaculture industries. In the present study, we cloned and characterized vasa and nanos3 and used them as germ cell markers in Atlantic cod. Sequencing results showed prospective vasa and nanos3 mRNA contained the domains used to describe their respective protein family. Furthermore, phylogenetic analysis using the amino acid sequence placed Atlantic cod Vasa distinct from representatives of three other taxonomic Superorders. Atlantic cod Nanos3 was placed with other homologues from the Nanos3 subfamily. Expression of both genes was detected from the first cleavage division; both were specifically expressed in Atlantic cod PGCs from the 32-cell stage. While nanos3 expression ceased during early somitogenesis, vasa was strongly expressed throughout embryonic development. Using vasa as a marker, we described the Atlantic cod PGC migration pattern. We demonstrated that Atlantic cod PGCs migrate ventral to the trunk mesoderm. With the exception of Pacific herring (Clupea pallasii), PGCs in other described teleost fishes migrate lateral to the trunk. The results from this study are the first step toward understanding germ line formation in Atlantic cod. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Development of a SNP resource and a genetic linkage map for Atlantic cod (Gadus morhua)

    Science.gov (United States)

    2010-01-01

    Background Atlantic cod (Gadus morhua) is a species with increasing economic significance for the aquaculture industry. The genetic improvement of cod will play a critical role in achieving successful large-scale aquaculture. While many microsatellite markers have been developed in cod, the number of single nucleotide polymorphisms (SNPs) is currently limited. Here we report the identification of SNPs from sequence data generated by a large-scale expressed sequence tag (EST) program, focusing on fish originating from Canadian waters. Results A total of 97976 ESTs were assembled to generate 13448 contigs. We detected 4753 SNPs that met our selection criteria (depth of coverage ≥ 4 reads; minor allele frequency > 25%). 3072 SNPs were selected for testing. The percentage of successful assays was 75%, with 2291 SNPs amplifying correctly. Of these, 607 (26%) SNPs were monomorphic for all populations tested. In total, 64 (4%) of SNPs are likely to represent duplicated genes or highly similar members of gene families, rather than alternative alleles of the same gene, since they showed a high frequency of heterozygosity. The remaining polymorphic SNPs (1620) were categorised as validated SNPs. The mean minor allele frequency of the validated loci was 0.258 (± 0.141). Of the 1514 contigs from which validated SNPs were selected, 31% have a significant blast hit. For the SNPs predicted to occur in coding regions (141), we determined that 36% (51) are non-synonymous. Many loci (1033 SNPs; 64%) are polymorphic in all populations tested. However a small number of SNPs (184) that are polymorphic in the Western Atlantic were monomorphic in fish tested from three European populations. A preliminary linkage map has been constructed with 23 major linkage groups and 924 mapped SNPs. Conclusions These SNPs represent powerful tools to accelerate the genetic improvement of cod aquaculture. They have been used to build a genetic linkage map that can be applied to quantitative trait

  8. Development of a SNP resource and a genetic linkage map for Atlantic cod (Gadus morhua

    Directory of Open Access Journals (Sweden)

    Higgins Brent

    2010-03-01

    Full Text Available Abstract Background Atlantic cod (Gadus morhua is a species with increasing economic significance for the aquaculture industry. The genetic improvement of cod will play a critical role in achieving successful large-scale aquaculture. While many microsatellite markers have been developed in cod, the number of single nucleotide polymorphisms (SNPs is currently limited. Here we report the identification of SNPs from sequence data generated by a large-scale expressed sequence tag (EST program, focusing on fish originating from Canadian waters. Results A total of 97976 ESTs were assembled to generate 13448 contigs. We detected 4753 SNPs that met our selection criteria (depth of coverage ≥ 4 reads; minor allele frequency > 25%. 3072 SNPs were selected for testing. The percentage of successful assays was 75%, with 2291 SNPs amplifying correctly. Of these, 607 (26% SNPs were monomorphic for all populations tested. In total, 64 (4% of SNPs are likely to represent duplicated genes or highly similar members of gene families, rather than alternative alleles of the same gene, since they showed a high frequency of heterozygosity. The remaining polymorphic SNPs (1620 were categorised as validated SNPs. The mean minor allele frequency of the validated loci was 0.258 (± 0.141. Of the 1514 contigs from which validated SNPs were selected, 31% have a significant blast hit. For the SNPs predicted to occur in coding regions (141, we determined that 36% (51 are non-synonymous. Many loci (1033 SNPs; 64% are polymorphic in all populations tested. However a small number of SNPs (184 that are polymorphic in the Western Atlantic were monomorphic in fish tested from three European populations. A preliminary linkage map has been constructed with 23 major linkage groups and 924 mapped SNPs. Conclusions These SNPs represent powerful tools to accelerate the genetic improvement of cod aquaculture. They have been used to build a genetic linkage map that can be applied to

  9. Genomic signatures of local directional selection in a high gene flow marine organism, the Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Hansen, Jakob Hemmer; Poulsen, Nina Aagaard

    2009-01-01

    -associated single nucleotide polymorphisms (SNPs) for evidence of selection in local populations of Atlantic cod (Gadus morhua L.) across the species distribution. Results: Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional...... selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread...

  10. The Effects of Temperature, Hypoxia and Hypercapnia on the Metabolism of Atlantic Cod Gadus morhua

    DEFF Research Database (Denmark)

    Tirsgård, Bjørn

    The Atlantic cod (Gadus morhua L. 1758) is an important species both as a major top predator in the ecosystem and economical marine resource in the fishing industry of Northern Europe (Andersen, 2012). As an ectothermic water breather the Atlantic cod is continuously exposed to annual changes...... into bio-energetic models used to predict survival, growth and reproduction rates and cod stock dynamics. Furthermore, due to the growing interest of the continuing global increase in atmospheric and oceanic CO2 levels (ICES, 2010), and the rapid expansion of fish farming in land-based recirculated...... species can survive in relatively high dissolved CO2 concentrations (hypercapnia) (Crocker and Cech, 1996; McKenzie et al., 2003), long-term exposure to sub-lethal environmental hypercapnia is known to affect growth, feed conversion efficiency and body condition index (Smart, 1981; Fivelstad et al., 1998...

  11. Impact of water-accommodated fractions of crude oil on Atlantic cod, Gadus morhua following chronic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Khan, R. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada)

    2010-07-01

    This study examined the long-term effects of hydrocarbon exposure on the gonadal development of fish. Mature Atlantic cod (Gadus morhua) were exposed to low concentrations of water accommodated fractions (WAFs) of polycyclic aromatic hydrocarbons (PAHs) in an ambient flowthrough seawater system. Some PAH-exposed cod groups were depurated afterwards for 38 to 287 days. Mortality was rare, and external lesions occurred only in the PAH-exposed groups. The gonado-somatic index revealed that gonadal development was disrupted in both sexes and spawning and spermiation was delayed in the 33 depurated PAH-groups. The findings indicate that chronic exposure to WAFs in the water column may have an adverse effect on reproduction in Atlantic cod.

  12. Unraveling the evolution of the Atlantic cod's (Gadus morhua L. alternative immune strategy.

    Directory of Open Access Journals (Sweden)

    Martin Malmstrøm

    Full Text Available Genes encoding the major histocompatibility complex (MHC have been thought to play a vital role in the adaptive immune system in all vertebrates. The discovery that Atlantic cod (Gadus morhua has lost important components of the MHC II pathway, accompanied by an unusually high number of MHC I genes, shed new light on the evolution and plasticity of the immune system of teleosts as well as in higher vertebrates. The overall aim of this study was to further investigate the highly expanded repertoire of MHC I genes using a cDNA approach to obtain sequence information of both the binding domains and the sorting signaling potential in the cytoplasmic tail. Here we report a novel combination of two endosomal sorting motifs, one tyrosine-based associated with exogenous peptide presentation by cross-presenting MHCI molecules, and one dileucine-based associated with normal MHC II functionality. The two signal motifs were identified in the cytoplasmic tail in a subset of the genes. This indicates that these genes have evolved MHC II-like functionality, allowing a more versatile use of MHC I through cross-presentation. Such an alternative immune strategy may have arisen through adaptive radiation and acquisition of new gene function as a response to changes in the habitat of its ancestral lineage.

  13. Spatial ecology of coastal Atlantic cod Gadus morhua associated with parasite load.

    Science.gov (United States)

    Aalvik, I M; Moland, E; Olsen, E M; Stenseth, N C

    2015-08-01

    Acoustic tags and receivers were used to investigate the spatial ecology of coastal Atlantic cod Gadus morhua (n = 32, mean fork length: 50 cm, range: 33-80 cm) on the Norwegian Skagerrak coast in 2012. Monthly home ranges (HR), swimming activity and depth use varied considerably among individuals and through the months of June, July and August. HR sizes for the period ranged from 0.25 to 5.20 km2 (mean = 2.30 km2. Two thirds of the tagged G. morhua were infected with black spot disease Cryptocotyle lingua parasites; these fish had larger HRs and occupied deeper water compared with non-infected fish. The infected fish also tended to be more active in terms of horizontal swimming. From an ecological and evolutionary perspective, any environmental change that modifies G. morhua behaviour may therefore also alter the parasite load of the population, and its conservation and fishery status. © 2015 The Fisheries Society of the British Isles.

  14. Molecular ontogenesis of digestive capability and associated endocrine control in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Kortner, Trond M; Overrein, Ingrid; Oie, Gunvor; Kjørsvik, Elin; Bardal, Tora; Wold, Per-Arvid; Arukwe, Augustine

    2011-10-01

    We have profiled the expression of twelve genes, in order to provide an overview on the molecular ontogeny of digestive capability with the associated endocrine control during Atlantic cod (Gadus morhua) larval development. Enzyme activity levels for the key digestive enzyme, trypsin, was also measured. Specifically, transcripts for trypsin, amylase, lipolytic enzymes: bile salt activated lipase (BAL), phospholipase A2 (PLA2) and Acyl CoA dehydrogenase (ACADM), regulatory peptides: neuropeptide Y (NPY), orexin (OX) cholecystokinin (CCK) and cocaine and amphetamine-related transcript (CART), the somatotropic factors: growth hormone (GH), preprosomatostatin 1 (PPSS1) and thyroid hormone receptors (TRα and TRβ) were analyzed using quatitative (real-time) polymerase chain reaction (qPCR). Trypsin and BAL mRNA levels peaked at approximately day 17 and 25 post-hatch, respectively, and thereafter displayed a decreasing pattern until metamorphosis. GH mRNA levels decreased moderately from 3 to 33dph, and thereafter, an increase was observed until 46dph. TRα mRNA levels showed a fluctuating pattern peaking at day 39 post-hatch. TRβ mRNA levels were too low to obtain quantitative measurements. Amylase mRNA slightly increased from day 3 to 17 post-hatch, and thereafter showed a steady decrease until day 60. Interestingly, PLA2 mRNA expression showed a consistent increase throughout the study period, indicating an increasingly important role during larval development. Overall, data from this study indicate that cod larvae show differential developmental mode of expression patterns for key genes and endocrine factors that regulate digestive capability, growth and development. These data are discussed in relation to larval trypsin enzyme activity and previous reports for other teleost species. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. Identification of Atlantic cod (Gadus morhua), ling (Molva molva), and Alaska pollock (Gadus chalcogrammus) by PCR-ELISA using duplex PCR.

    Science.gov (United States)

    Taboada, Ledicia; Sánchez, Ana; Velasco, Amaya; Santaclara, Francisco J; Pérez-Martín, Ricardo I; Sotelo, Carmen G

    2014-06-18

    Species-specific PCR-ELISA assays for the identification of Atlantic cod (Gadus morhua), Alaska pollock (Gadus chalcogrammus), and ling (Molva molva) in food products have been developed. The method, comprising a set of primers common to the first two species, a set of primers for M. molva, and a probe for each species, was designed using ND4 and cytochrome b genes as molecular markers. The sensitivity and selectivity were then determined for each assay. These assays were afterward used to analyze DNA extracted from commercial fish products. The presence of the target species was successfully detected in all analyzed samples, demonstrating the applicability of this method to the analysis of food products.

  16. Integrative Approach for the Reliable Detection and Specific Identification of the Microsporidium Loma morhua in Atlantic Cod (Gadus morhua).

    Science.gov (United States)

    Frenette, Aaron P; Eydal, Matthías; Hansen, Haakon; Burt, Michael D B; Duffy, Michael S

    2017-01-01

    Microsporidia are fungal parasites that infect diverse invertebrate and vertebrate hosts. Finfish aquaculture supports epizootics due to high host density and the high biotic potential of these parasites. Reliable methods for parasite detection and identification are a necessary precursor to empirical assessment of strategies to mitigate the effects of these pathogens during aquaculture. We developed an integrative approach to detect and identify Loma morhua infecting Atlantic cod. We show that the spleen is more reliable than the commonly presumed gills as best organ for parasite detection in spite of substantial morphological plasticity in xenoma complexes. We developed rDNA primers with 100% sensitivity in detecting L. morhua and with utility in distinguishing some congeneric Loma species. ITS sequencing is necessary to distinguish L. morhua from other congeneric microsporidia due to intraspecific nucleotide variation. 64% of L. morhua ITS variants from Atlantic cod have a 9-nucleotide motif that distinguishes it from Loma spp. infecting non-Gadus hosts. The remaining 36% of ITS variants from Atlantic cod are distinguished from currently represented Loma spp., particularly those infecting Gadus hosts, based on a 14-nucleotide motif. This research approach is amenable to developing templates in support of reliable detection and identification of other microsporidian parasites in fishes. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  17. Effects of ocean acidification increase embryonic sensitivity to thermal extremes in Atlantic cod, Gadus morhua.

    Science.gov (United States)

    Dahlke, Flemming T; Leo, Elettra; Mark, Felix C; Pörtner, Hans-Otto; Bickmeyer, Ulf; Frickenhaus, Stephan; Storch, Daniela

    2017-04-01

    Thermal tolerance windows serve as a powerful tool for estimating the vulnerability of marine species and their life stages to increasing temperature means and extremes. However, it remains uncertain to which extent additional drivers, such as ocean acidification, modify organismal responses to temperature. This study investigated the effects of CO 2 -driven ocean acidification on embryonic thermal sensitivity and performance in Atlantic cod, Gadus morhua, from the Kattegat. Fertilized eggs were exposed to factorial combinations of two PCO 2 conditions (400 μatm vs. 1100 μatm) and five temperature treatments (0, 3, 6, 9 and 12 °C), which allow identifying both lower and upper thermal tolerance thresholds. We quantified hatching success, oxygen consumption (MO 2 ) and mitochondrial functioning of embryos as well as larval morphometrics at hatch and the abundance of acid-base-relevant ionocytes on the yolk sac epithelium of newly hatched larvae. Hatching success was high under ambient spawning conditions (3-6 °C), but decreased towards both cold and warm temperature extremes. Elevated PCO 2 caused a significant decrease in hatching success, particularly at cold (3 and 0 °C) and warm (12 °C) temperatures. Warming imposed limitations to MO 2 and mitochondrial capacities. Elevated PCO 2 stimulated MO 2 at cold and intermediate temperatures, but exacerbated warming-induced constraints on MO 2 , indicating a synergistic interaction with temperature. Mitochondrial functioning was not affected by PCO 2 . Increased MO 2 in response to elevated PCO 2 was paralleled by reduced larval size at hatch. Finally, ionocyte abundance decreased with increasing temperature, but did not differ between PCO 2 treatments. Our results demonstrate increased thermal sensitivity of cod embryos under future PCO 2 conditions and suggest that acclimation to elevated PCO 2 requires reallocation of limited resources at the expense of embryonic growth. We conclude that ocean acidification

  18. Direct and social genetic parameters for growth and fin damage traits in Atlantic cod (Gadus morhua)

    Science.gov (United States)

    2014-01-01

    Background The aim of the study was to estimate genetic parameters for direct and social genetic effects (SGE) for growth and welfare traits in farmed Atlantic cod (Gadus morhua). A SGE refers to the effect of an individual’s genes on trait performance of its social partners. In total, 2100 individually tagged juveniles from 100 families at an average age of 222 days post-hatching were used. Each family was separated into three groups of seven fish, and were randomly assigned to 100 experimental tanks, together with fish from two other families. Body weight and length of the first, second and third dorsal fin and the caudal fin measured by digital image analysis were measured at the start of the experiment, after two weeks, and after six weeks. Fin erosion was scored subjectively after six weeks. Variance components estimated using a conventional animal model were compared to those of an animal model including a SGE. Results Heritabilities from the conventional animal model ranged from 0.24 to 0.34 for body weight and 0.05 to 0.80 for fin length. Heritabilities for fin erosion were highest for the first dorsal fin (0.83 ± 0.08, mean ± standard error) and lowest for the third dorsal fin (0.01 ± 0.04). No significant SGE were found for body weight, whereas SGE for fin lengths were significant after two and six weeks. Contributions to the total heritable variance were equal to 21.5% (6.1 ± 2.1) for the direct effect, 33.1% (9.4 ± 3.2) for the direct-social covariance, and 45.4% (12.9 ± 4.1) for the social variance for length of the first dorsal fin. For fin erosion, SGE were only significant for the second and third dorsal fin. Conclusions Including SGE for fin length and fin erosion in the animal model increased the estimated heritable variation. However, estimates of total heritable variances were inaccurate and a larger experiment is needed to accurately quantify total heritable variance. Despite this, our results demonstrate that

  19. Effects of sex, stock, and environment on the shape of known-age Atlantic cod ( Gadus morhua ) otoliths

    DEFF Research Database (Denmark)

    Cardinale, M.; Doering-Arjes, P.; Kastowsky, M.

    2004-01-01

    The effects of sex, stock, and environment on the shape of known-age Atlantic cod (Gadus morhua) otoliths from the Faroe Islands were investigated. Moreover, the feasibility of otolith shape analysis for stock identification was evaluated. The shape was described by using several normalized Fourier...... descriptors and morphometric variables. There were no consistent differences between the left and right otoliths and between sexes within different age classes, stocks, and environments. With our experimental design, we could evaluate the relative importance of genetic and environmental conditions (water....... The significant differences in otolith shape between Faroe Bank and Faroe Plateau cod stocks provided a phenotypic basis for stock separation. Stock and environmental influences were substantial in determining the shape of cod otoliths....

  20. Study of the plasma proteome of Atlantic cod (Gadus morhua): Effect of exposure to two PAHs and their corresponding diols.

    Science.gov (United States)

    Skogland Enerstvedt, Karianne; Sydnes, Magne O; Pampanin, Daniela M

    2017-09-01

    Occurrence of polycyclic aromatic hydrocarbon (PAH) contamination in the marine environment represents a risk to marine life and humans. In this study, plasma samples from Atlantic cod (Gadus morhua) were analysed by shotgun mass spectrometry to investigate the plasma proteome in response to exposure to single PAHs (naphthalene or chrysene) and their corresponding metabolites (dihydrodiols). In total, 369 proteins were identified and ranked according to their relative abundance. The levels of 12 proteins were found significantly altered in PAH exposed fish and are proposed as new biomarker candidates. Eleven proteins were upregulated, primarily immunoglobulin components, and one protein was downregulated (antifreeze protein type IV.) The uniformity of the upregulated proteins suggests a triggered immune response in the exposed fish. Overall, the results provide valuable knowledge for future studies of the Atlantic cod plasma proteome and generate grounds for establishing new plasma protein biomarkers for environmental monitoring of PAH related exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Plasma FITC-dextran exchange between the primary and secondary circulatory systems in the Atlantic cod, Gadus Morhua

    DEFF Research Database (Denmark)

    Fischer, Claes; Steffensen, John Fleng

    2008-01-01

    Fluorescein isothiocyanate dextran (FITC-dextran) exchange between the primary (PCS) and secondary (SCS) circulatory systems in the Atlantic cod, Gadus morhua (Linnaeus, 1752), were studied using 20-kDa (n = 4) and 500-kDa (n = 4) FITC-dextran. In order to give a qualitative perspective...... of the injected 500-kDa FITC-dextran was also examined, and it was observed that of the 500-kDa FITC-dextran lost from the primary and secondary vascular systems, 63.0 +/- 9.2% could be recovered from the liver....

  2. Large effective population size and temporal genetic stability in Atlantic cod (Gadus morhua) in the southern Gulf of St. Lawrence

    DEFF Research Database (Denmark)

    Therkildsen, Nina Overgaard; Eg Nielsen, Einar; Swain, Douglas P.

    2010-01-01

    compares the genetic variability at nine microsatellite loci in a Canadian population of Atlantic cod (Gadus morhua) over 80 years, spanning from before the fishery intensified to now when the population is at historically low abundance. Extensively validated genetic data from the temporally spaced samples......Worldwide, many commercial fish stocks have experienced dramatic declines due to overfishing. Such fisheries-induced population reductions could potentially erode the genetic diversity of marine fish populations. Based on analyses of DNA extracted from archived and contemporary samples, this paper...

  3. Residency, site fidelity and habitat use of Atlantic cod (Gadus morhua) at an offshore wind farm using acoustic telemetry.

    Science.gov (United States)

    Reubens, Jan T; Pasotti, Francesca; Degraer, Steven; Vincx, Magda

    2013-09-01

    Because offshore wind energy development is fast growing in Europe it is important to investigate the changes in the marine environment and how these may influence local biodiversity and ecosystem functioning. One of the species affected by these ecosystem changes is Atlantic cod (Gadus morhua), a heavily exploited, commercially important fish species. In this research we investigated the residency, site fidelity and habitat use of Atlantic cod on a temporal scale at windmill artificial reefs in the Belgian part of the North Sea. Acoustic telemetry was used and the Vemco VR2W position system was deployed to quantify the movement behaviour. In total, 22 Atlantic cod were tagged and monitored for up to one year. Many fish were present near the artificial reefs during summer and autumn, and demonstrated strong residency and high individual detection rates. When present within the study area, Atlantic cod also showed distinct habitat selectivity. We identified aggregation near the artificial hard substrates of the wind turbines. In addition, a clear seasonal pattern in presence was observed. The high number of fish present in summer and autumn alternated with a period of very low densities during the winter period. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Temperature Modulates the Effects of Ocean Acidification on Intestinal Ion Transport in Atlantic Cod, Gadus morhua.

    Science.gov (United States)

    Hu, Marian Y; Michael, Katharina; Kreiss, Cornelia M; Stumpp, Meike; Dupont, Sam; Tseng, Yung-Che; Lucassen, Magnus

    2016-01-01

    CO2-driven seawater acidification has been demonstrated to enhance intestinal bicarbonate secretion rates in teleosts, leading to an increased release of CaCO3 under simulated ocean acidification scenarios. In this study, we investigated if increasing CO2 levels stimulate the intestinal acid-base regulatory machinery of Atlantic cod (Gadus morhua) and whether temperatures at the upper limit of thermal tolerance stimulate or counteract ion regulatory capacities. Juvenile G. morhua were acclimated for 4 weeks to three CO2 levels (550, 1200, and 2200 μatm) covering present and near-future natural variability, at optimum (10°C) and summer maximum temperature (18°C), respectively. Immunohistochemical analyses revealed the subcellular localization of ion transporters, including Na(+)/K(+)-ATPase (NKA), Na(+)/H(+)-exchanger 3 (NHE3), Na(+)/[Formula: see text] cotransporter (NBC1), pendrin-like Cl(-)/[Formula: see text] exchanger (SLC26a6), V-type H(+)-ATPase subunit a (VHA), and Cl(-) channel 3 (CLC3) in epithelial cells of the anterior intestine. At 10°C, proteins and mRNA were generally up-regulated for most transporters in the intestinal epithelium after acclimation to higher CO2 levels. This supports recent findings demonstrating increased intestinal [Formula: see text] secretion rates in response to CO2 induced seawater acidification. At 18°C, mRNA expression and protein concentrations of most ion transporters remained unchanged or were even decreased, suggesting thermal compensation. This response may be energetically favorable to retain blood [Formula: see text] levels to stabilize pHe, but may negatively affect intestinal salt and water resorption of marine teleosts in future oceans.

  5. Temperature modulates the effects of ocean acidification on intestinal ion transport in Atlantic cod, Gadus morhua

    Directory of Open Access Journals (Sweden)

    Marian Yong-An Hu

    2016-06-01

    Full Text Available CO2-driven seawater acidification has been demonstrated to enhance intestinal bicarbonate secretion rates in teleosts, leading to an increased release of CaCO3 under simulated ocean acidification scenarios. In this study, we investigated if increasing CO2 levels stimulate the intestinal acid–base regulatory machinery of Atlantic cod (Gadus morhua and whether temperatures at the upper limit of thermal tolerance stimulate or counteract ion regulatory capacities. Juvenile G. morhua were acclimated for four weeks to three CO2 levels (550, 1,200 and 2,200 μatm covering present and near-future natural variability, at optimum (10°C and summer maximum temperature (18°C, respectively. Immunohistochemical analyses revealed the subcellular localization of ion transporters, including Na+/K+-ATPase (NKA, Na+/H+-exchanger 3 (NHE3, Na+/HCO3- cotransporter (NBC1, pendrin-like Cl-/HCO3- exchanger (SLC26a6, V-type H+-ATPase subunit a (VHA and Cl- channel 3 (CLC3 in epithelial cells of the anterior intestine. At 10°C, proteins and mRNA were generally up-regulated for most transporters in the intestinal epithelium after acclimation to higher CO2 levels. This supports recent findings demonstrating increased intestinal HCO3- secretion rates in response to CO2 induced seawater acidification. At 18°C, mRNA expression and protein concentrations of most ion transporters remained unchanged or were even decreased, suggesting thermal compensation. This response may be energetically favorable to retain blood HCO3- levels to stabilize pHe, but may negatively affect intestinal salt and water resorption of marine teleosts in future oceans.

  6. Temperature Modulates the Effects of Ocean Acidification on Intestinal Ion Transport in Atlantic Cod, Gadus morhua

    Science.gov (United States)

    Hu, Marian Y.; Michael, Katharina; Kreiss, Cornelia M.; Stumpp, Meike; Dupont, Sam; Tseng, Yung-Che; Lucassen, Magnus

    2016-01-01

    CO2-driven seawater acidification has been demonstrated to enhance intestinal bicarbonate secretion rates in teleosts, leading to an increased release of CaCO3 under simulated ocean acidification scenarios. In this study, we investigated if increasing CO2 levels stimulate the intestinal acid–base regulatory machinery of Atlantic cod (Gadus morhua) and whether temperatures at the upper limit of thermal tolerance stimulate or counteract ion regulatory capacities. Juvenile G. morhua were acclimated for 4 weeks to three CO2 levels (550, 1200, and 2200 μatm) covering present and near-future natural variability, at optimum (10°C) and summer maximum temperature (18°C), respectively. Immunohistochemical analyses revealed the subcellular localization of ion transporters, including Na+/K+-ATPase (NKA), Na+/H+-exchanger 3 (NHE3), Na+/HCO3− cotransporter (NBC1), pendrin-like Cl−/HCO3− exchanger (SLC26a6), V-type H+-ATPase subunit a (VHA), and Cl− channel 3 (CLC3) in epithelial cells of the anterior intestine. At 10°C, proteins and mRNA were generally up-regulated for most transporters in the intestinal epithelium after acclimation to higher CO2 levels. This supports recent findings demonstrating increased intestinal HCO3− secretion rates in response to CO2 induced seawater acidification. At 18°C, mRNA expression and protein concentrations of most ion transporters remained unchanged or were even decreased, suggesting thermal compensation. This response may be energetically favorable to retain blood HCO3− levels to stabilize pHe, but may negatively affect intestinal salt and water resorption of marine teleosts in future oceans. PMID:27313538

  7. Evaluation of Electrical Stunning of Atlantic Cod (Gadus morhua) and Turbot (Psetta maxima) in Seawater

    NARCIS (Netherlands)

    Lambooij, E.; Digre, H.; Erikson, U.; Reimert, H.G.M.; Burggraaf, D.; Vis, van de J.W.

    2013-01-01

    The aim of this study was to assess electrical stunning of Atlantic cod and turbot in seawater to develop a protocol for the process of stunning and killing. An induced general epileptiform insult (unconscious) had a duration of 40 ± 27 s (n =14) in cod (2.6 ± 0.5 kg) and 34 ± 18 s (n = 19) in

  8. Proteome changes in Atlantic cod (Gadus morhua) exposed to oil and produced water: Discovery of biomarker candidates for environmental monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kjersem, Anneli B

    2007-07-15

    Proteomics were applied to identify changes in the proteome of Atlantic cod (Gadus morhua) exposed to crude North Sea oil and North Sea produced water at different life stages and during early development. Apparent protein changes were identified and linked to possible signalling pathways and mechanisms involved in the biological response of fish following exposure. Exposure to North Sea crude oil and produced water appeared to induce a large number of changes, also at low levels of exposure. More than 40 of the 137 protein changes detected in plasma of juvenile cod following exposed to crude oil and surrogate produced water appeared at the lowest level of exposure, 0.06 ppm crude oil. Almost all of the protein changes detected in whole fry and fry liver following produced water exposure occurred at the lowest levels of produced water, 0.01% and 0.1% produced water

  9. In vitro pH-Stat protein hydrolysis of feed ingredients for Atlantic cod, Gadus morhua. 1. Development of the method

    NARCIS (Netherlands)

    Tibbetts, S.; Milley, J.E.; Ross, N.W.; Verreth, J.A.J.; Lall, S.P.

    2011-01-01

    The method described here involves the extraction and partial purification of an enzyme fraction from the dissected pyloric caeca of commercially farmed Atlantic cod, Gadus morhua (1 kg fish) and the development of a pH-Stat method to predict protein digestibility. The various extraction and partial

  10. Transferrin gene polymorphisms and population genetic studies of Atlantic cod (Gadus morhua

    Directory of Open Access Journals (Sweden)

    Berhan Asmamaw

    2016-01-01

    Full Text Available Objective: To detect single nucleotide polymorphisms (SNPs in the cod transferrin gene by comparing the sequences from Norwegian (North East Atlantic Ocean and Canadian (North West Atlantic Ocean specimen, and to quantify the genetic variation and differentiation in East and West Atlantic cod populations. Methods: cDNA sequences between individuals of Canadian (North West Atlantic Ocean and Norwegian (North East Atlantic Ocean origin were aligned. Allele frequencies of the SNPs were used to discriminate the different Atlantic cod populations in West/East Atlantic Ocean, and the Baltic Sea. Results: The sequence alignment detected 19 SNPs, of which 18 of them resulted in amino acid changes in the transferrin protein. Nonsynonymous to synonymous site substitution ratio (dn/ ds was by far greater than 1 providing an evidence for the existence of positive selection. The West Atlantic cod populations showed high values of heterozygosity and the Baltic populations were found to be inbred. Conclusions: This study identified and indicated transferrin gene polymorphisms that can be used for population differentiations.

  11. Composition and structure of the parasite faunas of cod, Gadus morhua L. (Teleostei: Gadidae, in the North East Atlantic

    Directory of Open Access Journals (Sweden)

    Kostadinova Aneta

    2008-07-01

    Full Text Available Abstract Background Although numerous studies on parasites of the Atlantic cod, Gadus morhua L. have been conducted in the North Atlantic, comparative analyses on local cod parasite faunas are virtually lacking. The present study is based on examination of large samples of cod from six geographical areas of the North East Atlantic which yielded abundant baseline data on parasite distribution and abundance. Materials and Methods A total of 826 fish was sampled in the Baltic, Celtic, Irish and North seas, Icelandic waters and Trondheimsfjord (Norway in 2002 (spring and autumn and 2003 (spring. The gills and internal organs (oesophagus, stomach, intestine, pyloric caeca, liver, heart, spleen, gall bladder and gonads were examined for macroparasites following a standardised protocol. The taxonomic consistency of the identification was ensured thorough the entire study. Results We discuss some problems in parasite identification, outline the composition of the parasite faunas in cod in the six North East Atlantic regions, provide novel data on parasite prevalence and abundance and a comparative assessment of the structure of the regional parasite faunas with respect to the higher-level taxonomic groupings, host specificity and zoogeographical distribution of the parasites. Altogether 57 different parasite forms were found including seven new host records (Diclidophora merlangi, Rhipidocotyle sp., Fellodistomum sp., Steringotrema sp., Cucullanus sp., Spinitectus sp., and Chondracanthus ornatus. The predominant groups of cod parasites were trematodes (19 species and nematodes (13 species including larval anisakids which comprised 58.2% of the total number of individuals. Conclusion Our study reveals relatively rich regional parasite faunas in cod from the North East Atlantic which are dominated by generalist parasites with Arcto-Boreal distribution. Further, it provides more detailed data on the distribution in the North East Atlantic of the majority

  12. Selection of reference genes for qRT-PCR examination of wild populations of Atlantic cod Gadus morhua

    Directory of Open Access Journals (Sweden)

    Lie Kai K

    2008-07-01

    Full Text Available Abstract Background Extensive sequencing efforts have been taking place for the Atlantic cod (Gadus morhua in recent years, the number of ESTs in the Genbank has reached more than 140.000. Despite its importance in North Atlantic fisheries and potential use in aquaculture, relatively few gene expression examination exists for this species, and systematic evaluations of reference gene stability in quantitative real-time RT-PCR (qRT-PCR studies are lacking. Results The stability of 10 potential reference genes was examined in six tissues of Atlantic cod obtained from four populations, to determine the most suitable genes to be used in qRT-PCR analyses. Relative transcription levels of genes encoding β-actin (ACTB, elongation factor 1A (EF1A, actin-related protein-2 (ARP-2, glyceraldehyde-3P-dehydrogenase (GAPDH, ubiquitin (Ubi, acidic ribosomal protein (ARP, ribosomal protein S9 (S9, ribosomal protein L4 (RPL4, RPL22 and RPL37 were quantified in gills, brain, liver, head kidney, muscle and middle intestine in six juvenile fish from three wild populations and from farmed Atlantic cod. Reference gene stability was investigated using the geNorm and NormFinder tools. Based on calculations performed with the geNorm, which determines the most stable genes from a set of tested genes in a given cDNA sample, ARP, Ubi, S9 and RPL37 were among the most stable genes in all tissues. When the same calculations were done with NormFinder, the same genes plus RPL4 and EF1A were ranked as the preferable genes. Conclusion Overall, this work suggests that the Ubi and ARP can be useful as reference genes in qRT-PCR examination of gene expression studying wild populations of Atlantic cod.

  13. Selection of reference genes for qRT-PCR examination of wild populations of Atlantic cod Gadus morhua.

    Science.gov (United States)

    Olsvik, Pål A; Søfteland, Liv; Lie, Kai K

    2008-07-16

    Extensive sequencing efforts have been taking place for the Atlantic cod (Gadus morhua) in recent years, the number of ESTs in the Genbank has reached more than 140.000. Despite its importance in North Atlantic fisheries and potential use in aquaculture, relatively few gene expression examination exists for this species, and systematic evaluations of reference gene stability in quantitative real-time RT-PCR (qRT-PCR) studies are lacking. The stability of 10 potential reference genes was examined in six tissues of Atlantic cod obtained from four populations, to determine the most suitable genes to be used in qRT-PCR analyses. Relative transcription levels of genes encoding beta-actin (ACTB), elongation factor 1A (EF1A), actin-related protein-2 (ARP-2), glyceraldehyde-3P-dehydrogenase (GAPDH), ubiquitin (Ubi), acidic ribosomal protein (ARP), ribosomal protein S9 (S9), ribosomal protein L4 (RPL4), RPL22 and RPL37 were quantified in gills, brain, liver, head kidney, muscle and middle intestine in six juvenile fish from three wild populations and from farmed Atlantic cod. Reference gene stability was investigated using the geNorm and NormFinder tools. Based on calculations performed with the geNorm, which determines the most stable genes from a set of tested genes in a given cDNA sample, ARP, Ubi, S9 and RPL37 were among the most stable genes in all tissues. When the same calculations were done with NormFinder, the same genes plus RPL4 and EF1A were ranked as the preferable genes. Overall, this work suggests that the Ubi and ARP can be useful as reference genes in qRT-PCR examination of gene expression studying wild populations of Atlantic cod.

  14. Back-calculated fish lengths and Hg and Zn levels from recent and 100-yr-old cleithrum bones from Atlantic Cod (Gadus morhua)

    Energy Technology Data Exchange (ETDEWEB)

    Scott, J.S.

    1977-01-01

    Dimensions of cleithrum bones from recently caught Atlantic cod (Gadus morhua) were measured and plotted against observed fish lengths to back-calculate cod lengths from cleithra from a ship wrecked in 1865. Mercury levels in the historical bones were approximately the same as those in recent material and showed no increase with fish length, but zinc levels appear to have increased since 1865 and increased with fish length.

  15. Yersiniosis in Atlantic cod, Gadus morhua (L.), characterization of the infective strain and host reactions.

    Science.gov (United States)

    Gudmundsdottir, B K; Gudmundsdottir, S; Gudmundsdottir, S; Magnadottir, B

    2014-06-01

    A disease outbreak in farmed Atlantic cod caused by Yersinia ruckeri is reported. Mortality started following vaccination of cod reared in two tanks (A and B). The accumulated mortality reached 1.9% in A and 4.8% in B in the following 30 days when treatment with oxytetracycline was applied. Biochemical and molecular analysis of Y. ruckeri isolates from the cod and other fish species from fresh and marine waters in Iceland revealed a high salinity-tolerant subgroup of Y. ruckeri serotype O1. Infected fish showed clinical signs comparable with those of Y. ruckeri -infected salmonids, with the exception of granuloma formations in infected cod tissues, which is a known response of cod to bacterial infections. Immunohistological examination showed Y. ruckeri antigens in the core of granulomas and the involvement of immune parameters that indicates a strong association between complement and lysozyme killing of bacteria. Experimental infection of cod with a cod isolate induced disease, and the calculated LD50 was 1.7 × 10(4) CFU per fish. The results suggest that yersiniosis can be spread between populations of freshwater and marine fish. Treatment of infected cod with antibiotic did not eliminate the infection, which can be explained by the immune response of cod producing prolonged granulomatous infection. © 2013 John Wiley & Sons Ltd.

  16. Automatic feeding and Harvesting of Juvenile Atlantic Cod (Gadus Morhua L. in a Pond

    Directory of Open Access Journals (Sweden)

    V. Øiestad

    1987-01-01

    Full Text Available Large scale production of juvenile Atlantic cod has been carried out since 1980 in a saltwater pond. A break-through was obtained in 1983 with high survival rates of cod larvae to metamorphosis. In 1985 we made progress in two fiels, reduced cannibalism and automatic harvesting. Juvenile cod formed large schools while fed dry pellets in the currents set up by five propellers. An underwater loudspeaker was programmed to give sound pulses just before feeding. During harvesting dry pellets were released inside a fish trap while giving the sound signals the cod juveniles were conditioned to. The cod readily entered the trap and a computer-controlled fish pump transported the fish from the fish trap into a storing tank and grading grids. The trap gradually emptied the pond of fish and more than 80

  17. Experimental Challenge of Atlantic Cod (Gadus morhua) with a Brucella pinnipedialis Strain from Hooded Seal (Cystophora cristata).

    Science.gov (United States)

    Nymo, Ingebjørg Helena; Seppola, Marit; Al Dahouk, Sascha; Bakkemo, Kathrine Ryvold; Jiménez de Bagüés, María Pilar; Godfroid, Jacques; Larsen, Anett Kristin

    2016-01-01

    Pathology has not been observed in true seals infected with Brucella pinnipedialis. A lack of intracellular survival and multiplication of B. pinnipedialis in hooded seal (Cystophora cristata) macrophages in vitro indicates a lack of chronic infection in hooded seals. Both epidemiology and bacteriological patterns in the hooded seal point to a transient infection of environmental origin, possibly through the food chain. To analyse the potential role of fish in the transmission of B. pinnipedialis, Atlantic cod (Gadus morhua) were injected intraperitoneally with 7.5 x 107 bacteria of a hooded seal field isolate. Samples of blood, liver, spleen, muscle, heart, head kidney, female gonads and feces were collected on days 1, 7, 14 and 28 post infection to assess the bacterial load, and to determine the expression of immune genes and the specific antibody response. Challenged fish showed an extended period of bacteremia through day 14 and viable bacteria were observed in all organs sampled, except muscle, until day 28. Neither gross lesions nor mortality were recorded. Anti-Brucella antibodies were detected from day 14 onwards and the expression of hepcidin, cathelicidin, interleukin (IL)-1β, IL-10, and interferon (IFN)-γ genes were significantly increased in spleen at day 1 and 28. Primary mononuclear cells isolated from head kidneys of Atlantic cod were exposed to B. pinnipedialis reference (NCTC 12890) and hooded seal (17a-1) strain. Both bacterial strains invaded mononuclear cells and survived intracellularly without any major reduction in bacterial counts for at least 48 hours. Our study shows that the B. pinnipedialis strain isolated from hooded seal survives in Atlantic cod, and suggests that Atlantic cod could play a role in the transmission of B. pinnipedialis to hooded seals in the wild.

  18. Experimental Challenge of Atlantic Cod (Gadus morhua with a Brucella pinnipedialis Strain from Hooded Seal (Cystophora cristata.

    Directory of Open Access Journals (Sweden)

    Ingebjørg Helena Nymo

    Full Text Available Pathology has not been observed in true seals infected with Brucella pinnipedialis. A lack of intracellular survival and multiplication of B. pinnipedialis in hooded seal (Cystophora cristata macrophages in vitro indicates a lack of chronic infection in hooded seals. Both epidemiology and bacteriological patterns in the hooded seal point to a transient infection of environmental origin, possibly through the food chain. To analyse the potential role of fish in the transmission of B. pinnipedialis, Atlantic cod (Gadus morhua were injected intraperitoneally with 7.5 x 107 bacteria of a hooded seal field isolate. Samples of blood, liver, spleen, muscle, heart, head kidney, female gonads and feces were collected on days 1, 7, 14 and 28 post infection to assess the bacterial load, and to determine the expression of immune genes and the specific antibody response. Challenged fish showed an extended period of bacteremia through day 14 and viable bacteria were observed in all organs sampled, except muscle, until day 28. Neither gross lesions nor mortality were recorded. Anti-Brucella antibodies were detected from day 14 onwards and the expression of hepcidin, cathelicidin, interleukin (IL-1β, IL-10, and interferon (IFN-γ genes were significantly increased in spleen at day 1 and 28. Primary mononuclear cells isolated from head kidneys of Atlantic cod were exposed to B. pinnipedialis reference (NCTC 12890 and hooded seal (17a-1 strain. Both bacterial strains invaded mononuclear cells and survived intracellularly without any major reduction in bacterial counts for at least 48 hours. Our study shows that the B. pinnipedialis strain isolated from hooded seal survives in Atlantic cod, and suggests that Atlantic cod could play a role in the transmission of B. pinnipedialis to hooded seals in the wild.

  19. Circadian rhythmicity and photic plasticity of myosin gene transcription in fast skeletal muscle of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Lazado, Carlo C; Nagasawa, Kazue; Babiak, Igor; Kumaratunga, Hiruni P S; Fernandes, Jorge M O

    2014-12-01

    The circadian rhythm is a fundamental adaptive mechanism to the daily environmental changes experienced by many organisms, including fish. Myosins constitute a large family of contractile proteins that are essential functional components of skeletal muscle. They are known to display thermal plasticity but the influence of light on myosin expression remains to be investigated in fish. In the present study, we have examined the circadian rhythmicity and photoperiodic plasticity of myosin gene transcription in Atlantic cod (Gadus morhua) fast skeletal muscle. In silico mining of the Atlantic cod genome resulted in the identification of 76 myosins representing different classes, many of which were hitherto uncharacterized. Among the 23 fast skeletal muscle myosin genes, myh_tc, myh_n1, myh_n4, myo18a_2, and myo18b_2 displayed circadian rhythmic expression and contained several circadian-related transcription factor binding sites (Creb, Mef2 and E-box motifs) within their putative promoter regions. Also, the circadian expression of these 5 myosins strongly correlated with the transcription pattern of clock genes in fast skeletal muscle. Under ex vivo conditions, myosin transcript levels lost their circadian rhythmicity. Nonetheless, different photoperiod regimes influenced the mRNA levels of myh_n4, myo18a_2 and myo18b_2 in fast skeletal muscle explants. Photoperiod manipulation in Atlantic cod juveniles revealed that continuous light significantly elevated mRNA levels of several myosins in fast skeletal muscle when compared to natural photoperiod. The daily rhythmicity observed in some fast skeletal muscle myosin genes suggests that they may be under circadian clock regulation. In addition, the influence of photoperiod on their expression implies that myosins may be involved in the photic plasticity of muscle growth observed in Atlantic cod. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Monitoring contaminants from oil production at sea by measuring gill EROD activity in Atlantic cod (Gadus morhua)

    Energy Technology Data Exchange (ETDEWEB)

    Abrahamson, Alexandra [Uppsala University, Department of Environmental Toxicology, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden)], E-mail: alexandra.abrahamson@ebc.uu.se; Brandt, Ingvar [Uppsala University, Department of Environmental Toxicology, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden)], E-mail: ingvar.brandt@ebc.uu.se; Brunstroem, Bjoern [Uppsala University, Department of Environmental Toxicology, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden)], E-mail: bjorn.brunstrom@ebc.uu.se; Sundt, Rolf C. [International Research Institute of Stavanger (IRIS), Akvamiljo, P.O. Box 8046, N-4068 Stavanger (Norway)], E-mail: rolf.sundt@irisresearch.no; Jorgensen, Even H. [Norwegian College of Fishery Science, University of Tromso, N-9037 Tromso (Norway); Norwegian Institute for Nature Research, Polar Environmental Centre, N-9296 Tromso (Norway)], E-mail: even.jorgensen@nfh.uit.no

    2008-05-15

    An ex vivo gill EROD assay was applied in Atlantic cod (Gadus morhua) as a biomarker for waterborne CYP1A-inducing compounds derived from oil production at sea. Exposure to nominal concentrations of 1 ppm or 10 ppm North Sea crude oil in a static water system for 24 h caused a concentration-dependent gill EROD induction. Further, exposure of cod for 14 days to environmentally relevant concentrations of produced water (PW, diluted 1:200 or 1:1000) from a platform in the North Sea using a flow-through system resulted in a concentration-dependent induction of gill EROD. Crude oil (0.2 ppm) from the same oil field also proved to induce EROD. Finally, gill EROD activity in cod caged for 6 weeks at 500-10 000 m from two platforms outside Norway was measured. The activities in these fish were very low and did not differ from those in fish caged at reference sites. - Gill EROD activity is a sensitive biomarker for CYP1A-inducing pollutants in cod.

  1. Genotype by Environment Interaction for Growth in Atlantic Cod (Gadus morhua L. in Four Farms of Norway

    Directory of Open Access Journals (Sweden)

    Rama Bangera

    2015-06-01

    Full Text Available We studied genotype by environment interaction (G × E for body weight (BW of Atlantic cod (Gadus morhua L. from the National cod breeding program in Norway. Records of 13,811 fish in a nucleus farm (NUC and two test farms (PENorth, PESouth in year-class (YC 2007, and for 9149 fish in NUC and one test farm in YC 2010 were available. Heterogeneity of variances and heritabilities ( were estimated using a univariate animal model with environmental effects common to full-sibs (full-model. Genetic correlations ( between farms were estimated using a multivariate full-model and a reduced-model (without for each YC. Heterogeneity of  was observed in both YC 2007 (0.10 to 0.16 and YC 2010 (0.08 to 0.26. The estimates of  between NUC and test farms were relatively high for both models (0.81 ± 0.19 to 0.96 ± 0.17 and (0.81 ± 0.08 to 0.86 ± 0.04, suggesting low re-ranking of genotypes. Strong re-ranking of genotypes between PESouth and PENorth may be less important because most cod producers are situated close to the breeding nucleus. In conclusion, G × E between NUC and test farms were low and at present there is no need for separate breeding programs for BW in cod.

  2. Historical DNA reveals the demographic history of Atlantic cod (Gadus morhua) in medieval and early modern Iceland.

    Science.gov (United States)

    Ólafsdóttir, Guðbjörg Ásta; Westfall, Kristen M; Edvardsson, Ragnar; Pálsson, Snæbjörn

    2014-02-22

    Atlantic cod (Gadus morhua) vertebrae from archaeological sites were used to study the history of the Icelandic Atlantic cod population in the time period of 1500-1990. Specifically, we used coalescence modelling to estimate population size and fluctuations from the sequence diversity at the cytochrome b (cytb) and Pantophysin I (PanI) loci. The models are consistent with an expanding population during the warm medieval period, large historical effective population size (NE), a marked bottleneck event at 1400-1500 and a decrease in NE in early modern times. The model results are corroborated by the reduction of haplotype and nucleotide variation over time and pairwise population distance as a significant portion of nucleotide variation partitioned across the 1550 time mark. The mean age of the historical fished stock is high in medieval times with a truncation in age in early modern times. The population size crash coincides with a period of known cooling in the North Atlantic, and we conclude that the collapse may be related to climate or climate-induced ecosystem change.

  3. Genomic analysis of the host response to nervous necrosis virus in Atlantic cod (Gadus morhua) brain.

    Science.gov (United States)

    Krasnov, Aleksei; Kileng, Øyvind; Skugor, Stanko; Jørgensen, Sven Martin; Afanasyev, Sergey; Timmerhaus, Gerrit; Sommer, Ann-Inger; Jensen, Ingvill

    2013-07-01

    Genome sequencing combined with transcriptome profiling promotes exploration of defence against pathogens and discovery of immune genes. Based on sequences from the recently released genome of Atlantic cod, a genome-wide oligonucleotide microarray (ACIQ-1) was designed and used for analyses of gene expression in the brain during infection with nervous necrosis virus (NNV). A challenge experiment with NNV was performed with Atlantic cod juveniles and brain samples from virus infected and uninfected fish were used for microarray analysis. Expression of virus induced genes increased at 5 days post challenge and persisted at stable level to the last sampling at 25 days post challenge. A large fraction of the up-regulated genes (546 features) were known or expected to have immune functions and most of these have not previously been characterized in Atlantic cod. Transcriptomic changes induced by the virus involved strong activation of genes associated with interferon and tumour necrosis factor related responses and acute inflammation. Up-regulation of genes involved in adaptive immunity suggested a rapid recruitment of B and T lymphocytes to the NNV infected brain. QPCR analyses of 15 candidate genes of innate immunity showed rapid induction by poly(I:C) in Atlantic cod larvae cells suggesting an antiviral role. Earliest and greatest expression changes after poly I:C stimulation was observed for interferon regulatory factors IRF4 and IRF7. Comparative studies between teleost species provided new knowledge about the evolution of innate antiviral immunity in fish. A number of genes is present or responds to viruses only in fish. Innate immunity of Atlantic cod is characterized by selective expansion of several medium-sized multigene families with ribose binding domains. An interesting finding was the high representation of three large gene families among the early antiviral genes, including tripartite motif proteins (TRIM) and proteins with PRY-SPRY and NACHT domains. The

  4. Effects of reproduction on growth and survival in Atlantic cod, Gadus morhua, assessed by comparison to triploids

    DEFF Research Database (Denmark)

    Trippel, Edward A.; Butts, Ian; Babin, Amanda

    2014-01-01

    in captive iteroparous, batch-spawning Atlantic cod (Gadus morhua), utilizing diploids and triploids, knowing that triploid females invest little to no energy into gametogenesis. Based on annual specific growth rate, there was no evidence for a somatic cost of reproduction at ages 2 (virgin year) and 4....... years, but there was at age 3. years. At age 2. years, low investment in reproduction likely accounted for the lack of a somatic cost of reproduction, whereas at age 4 the absence was associated with heightened growth post-spawning enabling mature fish to catch up to immature fish. At age 3......, compensatory growth during post-spawning was below that of immature fish. Survival represented a significant component of the cost of reproduction. Laboratory experiments examining the cost of reproduction have traditionally focused on shorter time periods, commonly spanning several months, whereas ours...

  5. Size-dependent social attraction and repulsion explains the decision of Atlantic cod Gadus morhua to enter baited pots.

    Science.gov (United States)

    Anders, N; Fernö, A; Humborstad, O-B; Løkkeborg, S; Rieucau, G; Utne-Palm, A C

    2017-11-15

    The present study tested whether the presence of already retained fishes inside baited fish pots acted as a social attraction and affected the entrance probability of Atlantic cod Gadus morhua in a fjord in northern Norway. Video analysis revealed that the probability of an entrance initially increased with the presence of low numbers of fishes inside the pot, but subsequently decreased at a critical number of caught fishes. The critical number was dependent on the size of the G. morhua attempting to enter. This demonstrates that social attraction and repulsion play a role in G. morhua pot fishing and has important implications for the capture efficiency of fisheries executed with pots. © 2017 The Fisheries Society of the British Isles.

  6. Diversification of the expanded teleost-specific toll-like receptor family in Atlantic cod, Gadus morhua

    Directory of Open Access Journals (Sweden)

    Sundaram Arvind YM

    2012-12-01

    Full Text Available Abstract Background Toll-like receptors (Tlrs are major molecular pattern recognition receptors of the innate immune system. Atlantic cod (Gadus morhua is the first vertebrate known to have lost most of the mammalian Tlr orthologues, particularly all bacterial recognising and other cell surface Tlrs. On the other hand, its genome encodes a unique repertoire of teleost-specific Tlrs. The aim of this study was to investigate if these duplicate Tlrs have been retained through adaptive evolution to compensate for the lack of other cell surface Tlrs in the cod genome. Results In this study, one tlr21, 12 tlr22 and two tlr23 genes representing the teleost-specific Tlr family have been cloned and characterised in cod. Phylogenetic analysis grouped all tlr22 genes under a single clade, indicating that the multiple cod paralogues have arisen through lineage-specific duplications. All tlrs examined were transcribed in immune-related tissues as well as in stomach, gut and gonads of adult cod and were differentially expressed during early development. These tlrs were also differentially regulated following immune challenge by immersion with Vibrio anguillarum, indicating their role in the immune response. An increase in water temperature from 4 to 12°C was associated with a 5.5-fold down-regulation of tlr22d transcript levels in spleen. Maximum likelihood analysis with different evolution models revealed that tlr22 genes are under positive selection. A total of 24 codons were found to be positively selected, of which 19 are in the ligand binding region of ectodomain. Conclusion Positive selection pressure coupled with experimental evidence of differential expression strongly support the hypothesis that teleost-specific tlr paralogues in cod are undergoing neofunctionalisation and can recognise bacterial pathogen-associated molecular patterns to compensate for the lack of other cell surface Tlrs.

  7. Diversification of the expanded teleost-specific toll-like receptor family in Atlantic cod, Gadus morhua

    Science.gov (United States)

    2012-01-01

    Background Toll-like receptors (Tlrs) are major molecular pattern recognition receptors of the innate immune system. Atlantic cod (Gadus morhua) is the first vertebrate known to have lost most of the mammalian Tlr orthologues, particularly all bacterial recognising and other cell surface Tlrs. On the other hand, its genome encodes a unique repertoire of teleost-specific Tlrs. The aim of this study was to investigate if these duplicate Tlrs have been retained through adaptive evolution to compensate for the lack of other cell surface Tlrs in the cod genome. Results In this study, one tlr21, 12 tlr22 and two tlr23 genes representing the teleost-specific Tlr family have been cloned and characterised in cod. Phylogenetic analysis grouped all tlr22 genes under a single clade, indicating that the multiple cod paralogues have arisen through lineage-specific duplications. All tlrs examined were transcribed in immune-related tissues as well as in stomach, gut and gonads of adult cod and were differentially expressed during early development. These tlrs were also differentially regulated following immune challenge by immersion with Vibrio anguillarum, indicating their role in the immune response. An increase in water temperature from 4 to 12°C was associated with a 5.5-fold down-regulation of tlr22d transcript levels in spleen. Maximum likelihood analysis with different evolution models revealed that tlr22 genes are under positive selection. A total of 24 codons were found to be positively selected, of which 19 are in the ligand binding region of ectodomain. Conclusion Positive selection pressure coupled with experimental evidence of differential expression strongly support the hypothesis that teleost-specific tlr paralogues in cod are undergoing neofunctionalisation and can recognise bacterial pathogen-associated molecular patterns to compensate for the lack of other cell surface Tlrs. PMID:23273344

  8. Development and experimental validation of a 20K Atlantic cod (Gadus morhua) oligonucleotide microarray based on a collection of over 150,000 ESTs.

    Science.gov (United States)

    Booman, Marije; Borza, Tudor; Feng, Charles Y; Hori, Tiago S; Higgins, Brent; Culf, Adrian; Léger, Daniel; Chute, Ian C; Belkaid, Anissa; Rise, Marlies; Gamperl, A Kurt; Hubert, Sophie; Kimball, Jennifer; Ouellette, Rodney J; Johnson, Stewart C; Bowman, Sharen; Rise, Matthew L

    2011-08-01

    The collapse of Atlantic cod (Gadus morhua) wild populations strongly impacted the Atlantic cod fishery and led to the development of cod aquaculture. In order to improve aquaculture and broodstock quality, we need to gain knowledge of genes and pathways involved in Atlantic cod responses to pathogens and other stressors. The Atlantic Cod Genomics and Broodstock Development Project has generated over 150,000 expressed sequence tags from 42 cDNA libraries representing various tissues, developmental stages, and stimuli. We used this resource to develop an Atlantic cod oligonucleotide microarray containing 20,000 unique probes. Selection of sequences from the full range of cDNA libraries enables application of the microarray for a broad spectrum of Atlantic cod functional genomics studies. We included sequences that were highly abundant in suppression subtractive hybridization (SSH) libraries, which were enriched for transcripts responsive to pathogens or other stressors. These sequences represent genes that potentially play an important role in stress and/or immune responses, making the microarray particularly useful for studies of Atlantic cod gene expression responses to immune stimuli and other stressors. To demonstrate its value, we used the microarray to analyze the Atlantic cod spleen response to stimulation with formalin-killed, atypical Aeromonas salmonicida, resulting in a gene expression profile that indicates a strong innate immune response. These results were further validated by quantitative PCR analysis and comparison to results from previous analysis of an SSH library. This study shows that the Atlantic cod 20K oligonucleotide microarray is a valuable new tool for Atlantic cod functional genomics research.

  9. Characterization of an Atlantic cod (Gadus morhua embryonic stem cell cDNA library

    Directory of Open Access Journals (Sweden)

    Holen Elisabeth

    2009-05-01

    Full Text Available Abstract Background The Atlantic cod is an ecologically and economically important North Atlantic fish species and also an emerging aquaculture species. To study gene expression in Atlantic cod embryonic stem (ES cells, our goal was to generate and analyze expressed sequence tags (ESTs from an ES cell cDNA library of mRNA consisting of approximately 3,900 ESTs. Results We sequenced 3,935 EST clones using a directional cDNA library made from pooled ES cells harvested at the blastula stage. Quality filtering of these ESTs allowed identification of 2,719 high-quality sequences with an average length of 442 bp containing 368 contigs and 1,276 singletons (1,644 unique sequences. BLASTX searches produced 889 significant (E-value -3 hits, of which 698 (42.5% were annotated with Gene Ontology terms (E-value -6. The number of unknown unique sequences was 946 (57.5%. All the high-quality EST sequences have been deposited in GenBank (GenBank: 2,719 sequences in UniGene library dbEST id: 22,021. Gene discovery and annotations are presented and discussed. Conclusion This set of ESTs represents one of the first attempts to describe mRNA in ES cells from a marine cold-water fish species, and provides a basis for gene expression studies of Atlantic cod ES cells.

  10. Novel mannose binding natterin-like protein in the skin mucus of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Rajan, Binoy; Patel, Deepti M; Kitani, Yoichiro; Viswanath, Kiron; Brinchmann, Monica F

    2017-09-01

    This study presents the first report of purification of natterin-like protein (Nlp) in a non-venomous fish. The peptide identities of purified cod Nlp were confirmed through LC-MSMS and matched to a cod expressed sequence tag (EST). A partial cod nlp nucleotide sequence was amplified and sequenced based on this EST. Multiple sequence alignment of cod Nlp showed considerable homology with other teleost Nlps and the presence of an N-terminal jacalin-like lectin domain coupled with a C-terminal toxin domain. nlp expression was higher in skin, head kidney, liver and spleen than in other tissues studied. Hemaggluttination of horse red blood cells by Nlp was calcium dependent and inhibited by mannose. A Vibrio anguillarum bath challenge however, did not alter the expression of cod nlp transcripts in the skin and gills. Further functional characterization is required to establish the significance of this unique protein in Atlantic cod and other teleosts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Dive to survive: effects of capture depth on barotraumaand post-release survival of Atlantic cod (Gadus morhua)in recreational fisheries

    OpenAIRE

    Ferter, Keno; Weltersbach, Marc Simon; Humborstad, Odd Børre; Fjelldal, Per Gunnar; Sambraus, Florian; Strehlow, Harry Vincent; Vølstad, Jon Helge

    2015-01-01

    - Atlantic cod (Gadus morhua) caught in recreational fisheries are commonly released, often with barotrauma after rapid decompression. Mouth-hooked, non-bleeding cod kept in a floating net pen showed mortalities ≥40% when angled from >50 m depth, likely because of cumulative stress from ongoing barotrauma and exposure to warm surface water. In a natural setting, however, cod have the opportunity to descend after release and are not restricted to the surface. In a follow-up study, 97.8% of ...

  12. Dive to survive: effects of capture depth on barotrauma and post-release survival of Atlantic cod (Gadus morhua) in recreational fisheries

    OpenAIRE

    Ferter, Keno; Weltersbach, Marc Simon; Humborstad, Odd Børre; Fjelldal, Per Gunnar; Sambraus, Florian; Strehlow, Harry Vincent; Vølstad, Jon Helge

    2015-01-01

    Atlantic cod (Gadus morhua) caught in recreational fisheries are commonly released, often with barotrauma after rapid decompression. Mouth-hooked, non-bleeding cod kept in a floating net pen showed mortalities ≥40% when angled from >50 m depth, likely because of cumulative stress from ongoing barotrauma and exposure to warm surface water. In a natural setting, however, cod have the opportunity to descend after release and are not restricted to the surface. In a follow-up study, 97.8% of simil...

  13. Amino acid sequence of the cold-active alkaline phosphatase from Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Asgeirsson, Bjarni; Nielsen, Berit Noesgaard; Højrup, Peter

    2003-01-01

    Atlantic cod is a marine fish that lives at low temperatures of 0-10 degrees C and contains a cold-adapted alkaline phosphatase (AP). Preparations of AP from either the lower part of the intestines or the pyloric caeca area were subjected to proteolytic digestion, mass spectrometry and amino acid...... has the same variable residues as mammalian APs (His153 and His328 by E. coli AP numbering). General comparison of the amino acid composition with mammalian APs showed that cod AP contains fewer Cys, Leu, Met and Ser, but proportionally more Asn, Asp, Ile, Lys, Trp and Tyr residues. Three N......-linked glycosylation sites were found. The glycan structure was determined as complex biantennary in type with fucose and sialic acid attached, although a trace of complex tri-antennary structure was also observed. A three-dimensional model was obtained by homology modelling using the human placental AP scaffold. Cod...

  14. Integrating the markers Pan I and haemoglobin with the genetic linkage map of Atlantic cod (Gadus morhua

    Directory of Open Access Journals (Sweden)

    Simpson Gary

    2010-10-01

    Full Text Available Abstract Background Haemoglobin (Hb and pantophysin (Pan I markers have been used intensively in population studies of Atlantic cod (Gadus morhua and in the analysis of traits such as temperature tolerance, growth characteristics and sexual maturation. We used an Illumina GoldenGate panel and the KASPar SNP genotyping system to analyse SNPs in three Atlantic cod families, one of which was polymorphic at the Hb β1 locus, and to generate a genetic linkage map integrating Pan I and multiple Hb loci. Findings Data generated allowed the mapping of nine Hb loci, the Pan I locus, and other 122 SNPs onto an existing linkage genetic map for Atlantic cod. Four Hb genes (i.e. α1, α4, β1 and β5 have been mapped on linkage group (LG 2 while the other five (i.e. α2, α3, β2, β3 and β4 were placed on LG18. Pan I was mapped on LG 1 using a newly developed KASPar assay for a SNP variable only in Pan IA allelic variants. The new linkage genetic map presented here comprises 1046 SNPs distributed between 23 linkage groups, with a length of 1145.6 cM. A map produced by forcing additional loci, resulting in a reduced goodness-of-fit for mapped markers, allowed the mapping of a total of 1300 SNPs. Finally, we compared our genetic linkage map data with the genetic linkage map data produced by a different group and identified 29 shared SNPs distributed on 10 different linkage groups. Conclusions The genetic linkage map presented here incorporates the marker Pan I, together with multiple Hb loci, and integrates genetic linkage data produced by two different research groups. This represents a useful resource to further explore if Pan I and Hbs or other genes underlie quantitative trait loci (QTL for temperature sensitivity/tolerance or other phenotypes.

  15. Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.).

    Science.gov (United States)

    Vo, Tu A; Galloway, Trina F; Bardal, Tora; Halseth, Christine K; Øie, Gunvor; Kjørsvik, Elin

    2016-11-15

    Dynamics between hypertrophy (increase in cell size) and hyperplasia (increase in cell numbers) of white and red muscle in relation to body size [standard length (SL)], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua). Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph), Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph), and a positive long term effect on muscle hypertrophy (60 dph). The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm), where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance. © 2016. Published by The Company of Biologists Ltd.

  16. Thermal habitat constraints on zooplankton species associated with Atlantic cod (Gadus morhua) on the US Northeast Continental Shelf

    Science.gov (United States)

    Friedland, Kevin D.; Kane, Joe; Hare, Jonathan A.; Lough, R. Gregory; Fratantoni, Paula S.; Fogarty, Michael J.; Nye, Janet A.

    2013-09-01

    The US Northeast Continental Shelf is experiencing a period of increasing temperature levels and range, which impacts the quantity of thermal habitats within the ecosystem. With increasing temperatures, the amount of warmer, surface water thermal habitats (16-27 °C) has increased while there has been a reciprocal decline in cooler water habitats (5-15 °C). These cooler water habitats are the most abundant and comprise the core habitats of the ecosystem. The coldest thermal habitats (1-4 °C), however, have increased slightly in amount or have remained constant, reflecting a discontinuity in the progression of warming along a latitudinal gradient. This discontinuity may be the result of recent changes in the circulation of water masses in the northern Gulf of Maine, potentially associated with the Labrador Current. The contraction of core thermal habitats appears to have had biological consequences on multiple trophic levels. In particular, two zooplankton species associated with the larval feeding of Atlantic cod, Gadus morhua, have declined in abundance in the same areas where cod populations have exhibited continually poor recruitment. The zooplankton species group Pseudocalanus spp., which is associated with winter-spawning cod, has declined on Georges Bank and in the Eastern Gulf of Maine. The zooplankton Centropages typicus has declined in the Gulf of Maine during late summer into fall, potentially affecting spring-spawning cod in that area. These observations are consistent with the hypothesis that portions of the population complex of cod have lower reproductive output due to changes in zooplankton abundance, which we associate with the distribution of temperatures within the ecosystem.

  17. Skeletal muscle growth dynamics and the influence of first-feeding diet in Atlantic cod larvae (Gadus morhua L.

    Directory of Open Access Journals (Sweden)

    Tu A. Vo

    2016-11-01

    Full Text Available Dynamics between hypertrophy (increase in cell size and hyperplasia (increase in cell numbers of white and red muscle in relation to body size [standard length (SL], and the influence of the first-feeding diets on muscle growth were investigated in Atlantic cod larvae (Gadus morhua. Cod larvae were fed copepod nauplii or rotifers of different nutritional qualities from 4 to 29 days post hatching (dph, Artemia nauplii from 20 to 40 dph and a formulated diet from 36 to 60 dph. The short period of feeding with cultivated copepod nauplii had a positive effect on both muscle hyperplasia and hypertrophy after the copepod/rotifer phase (19 dph, and a positive long term effect on muscle hypertrophy (60 dph. The different nutritional qualities of rotifers did not significantly affect muscle growth. We suggest here a model of the dynamics between hyperplasia and hypertrophy of red and white muscle fibre cells in relation to cod SL (4 to 30 mm, where the different red and white muscle growth phases clearly coincided with different metamorphosis stages in cod larvae. These shifts could be included as biomarkers for the different stages of development during metamorphosis. The main dietary muscle effect was that hypertrophic growth of red muscle fibres was stronger in cod larvae that were fed copepods than in larvae that were fed rotifers, both in relation to larval age and size. Red muscle fibres are directly involved in larval locomotory performance, but may also play an important role in the larval myogenesis. This can have a long term effect on growth potential and fish performance.

  18. An integrated approach to gene discovery and marker development in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Bowman, Sharen; Hubert, Sophie; Higgins, Brent; Stone, Cynthia; Kimball, Jennifer; Borza, Tudor; Bussey, Jillian Tarrant; Simpson, Gary; Kozera, Catherine; Curtis, Bruce A; Hall, Jennifer R; Hori, Tiago S; Feng, Charles Y; Rise, Marlies; Booman, Marije; Gamperl, A Kurt; Trippel, Edward; Symonds, Jane; Johnson, Stewart C; Rise, Matthew L

    2011-04-01

    Atlantic cod is a species that has been overexploited by the capture fishery. Programs to domesticate this species are underway in several countries, including Canada, to provide an alternative route for production. Selective breeding programs have been successfully applied in the domestication of other species, with genomics-based approaches used to augment conventional methods of animal production in recent years. Genomics tools, such as gene sequences and sets of variable markers, also have the potential to enhance and accelerate selective breeding programs in aquaculture, and to provide better monitoring tools to ensure that wild cod populations are well managed. We describe the generation of significant genomics resources for Atlantic cod through an integrated genomics/selective breeding approach. These include 158,877 expressed sequence tags (ESTs), a set of annotated putative transcripts and several thousand single nucleotide polymorphism markers that were developed from, and have been shown to be highly variable in, fish enrolled in two selective breeding programs. Our EST collection was generated from various tissues and life cycle stages. In some cases, tissues from which libraries were generated were isolated from fish exposed to stressors, including elevated temperature, or antigen stimulation (bacterial and viral) to enrich for transcripts that are involved in these response pathways. The genomics resources described here support the developing aquaculture industry, enabling the application of molecular markers within selective breeding programs. Marker sets should also find widespread application in fisheries management.

  19. Impact of asymptomatic nodavirus carrier state and intraperitoneal viral mimic injection on brain transcript expression in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Rise, Matthew L; Hall, Jennifer R; Rise, Marlies; Hori, Tiago S; Browne, Mitchell J; Gamperl, A Kurt; Hubert, Sophie; Kimball, Jennifer; Bowman, Sharen; Johnson, Stewart C

    2010-07-07

    Nodaviruses and other RNA viruses have a profoundly negative impact on the global aquaculture industry. Nodaviruses target nervous tissue causing viral nervous necrosis, a disease characterized by neurological damage, swimming abnormalities, and morbidity. This study used functional genomic techniques to study the Atlantic cod (Gadus morhua) brain transcript expression responses to asymptomatic high nodavirus carrier state and intraperitoneal injection of polyriboinosinic polyribocytidylic acid (pIC). Reciprocal suppression subtractive hybridization (SSH) cDNA libraries enriched for virus-responsive brain transcripts were constructed and characterized. We generated 1,938 expressed sequence tags (ESTs) from a forward brain SSH library (enriched for transcripts upregulated by nodavirus and/or pIC) and 1,980 ESTs from a reverse brain SSH library (enriched for transcripts downregulated by nodavirus and/or pIC). To examine the effect of nodavirus carrier state on individual brain gene expression in asymptomatic cod, 27 transcripts of interest were selected for quantitative reverse transcription-polymerase chain reaction (QPCR) studies. Transcripts found to be >10-fold upregulated in individuals with a high nodavirus carrier state relative to those in a no/low nodavirus carrier state were identified as ISG15, IL8, DHX58 (alias LGP2), ZNFX1, RSAD2 (alias viperin), and SACS (sacsin, alias spastic ataxia of Charlevoix-Saguenay). These and other SSH-identified transcripts were also found by QPCR to be significantly (P SSH library, including two putative ubiquitination pathway members (HERC4 and SUMO2), were found to be significantly (P < 0.05) downregulated in individuals with a high nodavirus carrier state. Our data shows that Atlantic cod brains have a strong interferon pathway response to asymptomatic high nodavirus carrier state and that many interferon pathway and other immune relevant transcripts are significantly induced in brain by both nodavirus and pIC.

  20. Environmentally realistic exposure to weathered North Sea oil: Sublethal effects in Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus).

    Science.gov (United States)

    Holth, Tor Fredrik; Storset, Audun; Ribeiro, Anne Luise; Ólafsdóttir, Ásdís; Halldórsson, Halldór Pálmar; Hylland, Ketil

    2017-01-01

    With increasing oil and gas activities and transport in the Arctic, there is a need to understand how operational or accidental releases of substances affect marine organisms from a pristine environment. The aim of the current study was to describe and compare the responses of two marine fish species, Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus), following exposure to three levels (low, medium, high) of the water-soluble fraction of a North Sea crude oil for 16 days. The exposure system simulated environmental exposure by allowing clean seawater to percolate through gravel covered in weathered oil before being introduced to aquaria. Both polycyclic aromatic hydrocarbon (PAH) metabolite bile concentrations and cytochrome P4501A (CYP1A) levels and activity increased markedly in comparison with controls in both species, but there were no significant differences between the three exposures. Turbot possessed 4-5-fold higher concentrations of two PAH bile metabolites compared to Atlantic cod by day 8. In contrast, hepatic CYP1A activity in cod was consistently 2-6-fold higher than in turbot with increasing differences over the experimental period. Baseline DNA strand breaks in lymphocytes and kidney cells were low in both species, but was elevated for all treatments by day two. There were no marked indications of the treatments affecting immune functions in either species. This investigation demonstrated that there may be significant differences in responses between species receiving identical exposures and that DNA strand breaks in lymphocytes and kidney cells are sensitive to confinement stress. Data also indicate that some species, such as turbot, may adapt to treatments within days and weeks.

  1. Gene regulation of lipid and phospholipid metabolism in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Li, Keshuai; Østensen, Mari-Ann; Attramadal, Kari; Winge, Per; Sparstad, Torfinn; Bones, Atle M; Vadstein, Olav; Kjørsvik, Elin; Olsen, Yngvar

    2015-12-01

    The mechanism of essentiality of dietary phospholipid (PL) for larval fish is not clear. The main objective of the present study was to determine if the PL requirement of Atlantic cod larvae was due to any genetic impairment caused by functional immaturity. Cod larvae were sampled at 1, 3, 8, 13, 17, 18, 30, 42 and 60 days post hatch (dph) for transcriptome analysis using a recently developed microarray. The fatty acid profile and gene expression levels of cod larvae at 17 dph were compared after feeding differently enriched rotifers, which contained different DHA levels in PL. No significant differences (pcod larvae, their growth and survival, and their DHA levels in total lipid and PL fraction. The fatty acid data suggested that dietary EPA was elongated to DPA by cod larvae, and a threshold DHA level in PL to maintain membrane fluidity and other functions may exist. There appeared to be no major effect of development on the expression of key genes of PL biosynthesis suggesting no genetic constrain in early developmental stages. Our overall data suggested that besides the possible limited de novo PC synthesis ability in the intestine, other metabolic constraints should also be considered, especially the possible low input of bile PC as a result of immature liver. Further studies are needed to elucidate the gene expression level and enzyme activity in the PL biosynthesis pathways for specific tissue or cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Physiological and behavioural responses to noxious stimuli in the Atlantic cod (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Jared R Eckroth

    Full Text Available In the present study, our aim was to compare physiological and behavioural responses to different noxious stimuli to those of a standardized innocuous stimulus, to possibly identify aversive responses indicative of injury detection in a commercially important marine teleost fish, the Atlantic cod. Individual fish were administered with a noxious stimulus to the lip under short-term general anaesthesia (MS-222. The noxious treatments included injection of 0.1% or 2% acetic acid, 0.005% or 0.1% capsaicin, or piercing the lip with a commercial fishing hook. Counts of opercular beat rate (OBR at 10, 30, 60, 90 and 120 min and observations of behaviour at 30 and 90 min post-treatment were compared with pre-treatment values and with control fish injected with physiological saline, an innocuous stimulus. Circulatory levels of physiological stress indicators were determined in all fish at 120 minutes post-treatment. All treatments evoked temporarily increased OBR that returned to pre-treatment levels at 60 minutes (saline, 0.005% capsaicin, hook, 90 minutes (0.1% acetic acid, 0.1% capsaicin, or 120 minutes (2% acetic acid, but with no significant differences from the control group at any time point. Fish treated with 0.1% and 2% acetic acid and 0.1% capsaicin displayed increased hovering close to the bottom of the aquaria and fish given 2% acetic acid and 0.1% capsaicin also displayed a reduced use of shelter. The only effect seen in hooked fish was brief episodes of lateral head shaking which were not seen pre-treatment or in the other groups, possibly reflecting a resiliency to tissue damage in the mouth area related to the tough nature of the Atlantic cod diet. There were no differences between groups in circulatory stress indicators two hours after treatment. This study provides novel data on behavioural indicators that could be used to assess potentially aversive events in Atlantic cod.

  3. Physiological and Behavioural Responses to Noxious Stimuli in the Atlantic Cod (Gadus morhua)

    Science.gov (United States)

    Eckroth, Jared R.; Aas-Hansen, Øyvind; Sneddon, Lynne U.; Bichão, Helena; Døving, Kjell B.

    2014-01-01

    In the present study, our aim was to compare physiological and behavioural responses to different noxious stimuli to those of a standardized innocuous stimulus, to possibly identify aversive responses indicative of injury detection in a commercially important marine teleost fish, the Atlantic cod. Individual fish were administered with a noxious stimulus to the lip under short-term general anaesthesia (MS-222). The noxious treatments included injection of 0.1% or 2% acetic acid, 0.005% or 0.1% capsaicin, or piercing the lip with a commercial fishing hook. Counts of opercular beat rate (OBR) at 10, 30, 60, 90 and 120 min and observations of behaviour at 30 and 90 min post-treatment were compared with pre-treatment values and with control fish injected with physiological saline, an innocuous stimulus. Circulatory levels of physiological stress indicators were determined in all fish at 120 minutes post-treatment. All treatments evoked temporarily increased OBR that returned to pre-treatment levels at 60 minutes (saline, 0.005% capsaicin, hook), 90 minutes (0.1% acetic acid, 0.1% capsaicin), or 120 minutes (2% acetic acid), but with no significant differences from the control group at any time point. Fish treated with 0.1% and 2% acetic acid and 0.1% capsaicin displayed increased hovering close to the bottom of the aquaria and fish given 2% acetic acid and 0.1% capsaicin also displayed a reduced use of shelter. The only effect seen in hooked fish was brief episodes of lateral head shaking which were not seen pre-treatment or in the other groups, possibly reflecting a resiliency to tissue damage in the mouth area related to the tough nature of the Atlantic cod diet. There were no differences between groups in circulatory stress indicators two hours after treatment. This study provides novel data on behavioural indicators that could be used to assess potentially aversive events in Atlantic cod. PMID:24936652

  4. Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua at superchilled temperatures

    Directory of Open Access Journals (Sweden)

    Marteinsson Viggó

    2009-12-01

    Full Text Available Abstract Background The bacteriology during storage of the North-Atlantic cod has been investigated for the past decades using conventional cultivation strategies which have generated large amount of information. This paper presents a study where both conventional cultivation and cultivation independent approaches were used to investigate the bacterial succession during storage of cod loins at chilled and superchilled temperatures. Results Unbrined (0.4% NaCl and brined (2.5% NaCl cod loins were stored at chilled (0°C and superchilled (-2 and -3.6°C temperatures in air or modified atmosphere (MA, % CO2/O2/N2: 49.0 ± 0.6/7.4 ± 0.2/43.7 ± 0.4. Discrepancy was observed between cultivation enumeration and culture independent methods where the former showed a general dominance of Pseudomonas spp. (up to 59% while the latter showed a dominance of Photobacterium phosphoreum (up to 100%. Gas chromatography-mass spectrophotometry (GC-MC showed that trimethylamine was the most abundant volatile in mid- and late storage periods. Terminal restriction polymorphism (t-RFLP analysis showed that the relative abundance of P. phosphoreum increased with storage time. Conclusion The present study shows the bacteriological developments on lightly salted or non-salted cod loins during storage at superchilled temperatures. It furthermore confirms the importance of P. phosphoreum as a spoilage organism during storage of cod loins at low temperatures using molecular techniques. The methods used compensate each other, giving more detailed data on bacterial population developments during spoilage.

  5. Bacterial composition and succession during storage of North-Atlantic cod (Gadus morhua) at superchilled temperatures

    Science.gov (United States)

    2009-01-01

    Background The bacteriology during storage of the North-Atlantic cod has been investigated for the past decades using conventional cultivation strategies which have generated large amount of information. This paper presents a study where both conventional cultivation and cultivation independent approaches were used to investigate the bacterial succession during storage of cod loins at chilled and superchilled temperatures. Results Unbrined (0.4% NaCl) and brined (2.5% NaCl) cod loins were stored at chilled (0°C) and superchilled (-2 and -3.6°C) temperatures in air or modified atmosphere (MA, % CO2/O2/N2: 49.0 ± 0.6/7.4 ± 0.2/43.7 ± 0.4). Discrepancy was observed between cultivation enumeration and culture independent methods where the former showed a general dominance of Pseudomonas spp. (up to 59%) while the latter showed a dominance of Photobacterium phosphoreum (up to 100%). Gas chromatography-mass spectrophotometry (GC-MC) showed that trimethylamine was the most abundant volatile in mid- and late storage periods. Terminal restriction polymorphism (t-RFLP) analysis showed that the relative abundance of P. phosphoreum increased with storage time. Conclusion The present study shows the bacteriological developments on lightly salted or non-salted cod loins during storage at superchilled temperatures. It furthermore confirms the importance of P. phosphoreum as a spoilage organism during storage of cod loins at low temperatures using molecular techniques. The methods used compensate each other, giving more detailed data on bacterial population developments during spoilage. PMID:19961579

  6. Identification of an albumin-like protein in plasma of Atlantic cod (Gadus morhua and its biomarker potential for PAH contamination

    Directory of Open Access Journals (Sweden)

    Karianne Skogland Enerstvedt

    2017-08-01

    Full Text Available Increased research efforts are currently focusing on Atlantic cod (Gadus morhua and its significance for monitoring the contaminant situation in marine environments. Polycyclic aromatic hydrocarbons (PAHs are well known toxic and carcinogenic compounds, thus continuous monitoring is required to ensure ecosystem sustainability and human food safety. A sensitive biomarker of PAH exposure in humans is the detection of PAH metabolites bound to albumin in blood. The potential of a similar PAH-albumin biomarker in Atlantic cod was therefore investigated by a desktop bioinformatic study followed by liquid chromatography mass spectrometry/mass spectrometry analysis of plasma from 16 fish. For the first time, an albumin-like protein in plasma of Atlantic cod is described, and the biomarker potential based on PAH-albumin adduct detection is discussed. Due to the detected low abundance of the albumin-like protein, it was found unlikely to be applicable as a new biomarker tool for evaluation of PAH exposure.

  7. Identification of an albumin-like protein in plasma of Atlantic cod (Gadus morhua) and its biomarker potential for PAH contamination.

    Science.gov (United States)

    Enerstvedt, Karianne Skogland; Sydnes, Magne O; Pampanin, Daniela M

    2017-08-01

    Increased research efforts are currently focusing on Atlantic cod (Gadus morhua) and its significance for monitoring the contaminant situation in marine environments. Polycyclic aromatic hydrocarbons (PAHs) are well known toxic and carcinogenic compounds, thus continuous monitoring is required to ensure ecosystem sustainability and human food safety. A sensitive biomarker of PAH exposure in humans is the detection of PAH metabolites bound to albumin in blood. The potential of a similar PAH-albumin biomarker in Atlantic cod was therefore investigated by a desktop bioinformatic study followed by liquid chromatography mass spectrometry/mass spectrometry analysis of plasma from 16 fish. For the first time, an albumin-like protein in plasma of Atlantic cod is described, and the biomarker potential based on PAH-albumin adduct detection is discussed. Due to the detected low abundance of the albumin-like protein, it was found unlikely to be applicable as a new biomarker tool for evaluation of PAH exposure.

  8. Influence of environmental changes in the north-western Atlantic Ocean on a parasite, Echinorhynchus gadi (Acanthocephala) of Atlantic cod ( Gadus morhua) occurring off coastal Labrador, Canada.

    Science.gov (United States)

    Khan, R A

    2008-09-01

    A study was conducted to determine the influence of environmental change on an endoparasite, Echinorhynchus gadi (Acanthocephala) of Atlantic cod (Gadus morhua) over a 30-year period off the coast of Labrador in the north-western Atlantic, North Atlantic Fisheries Organization subareas 2J-3K. Cod, once an abundant fish species that had been commercially exploited for many decades, declined precipitously during the mid-1980s onwards. This decline was attributed to climatic changes that affected the entire food chain from zooplankton to fish, sea birds and marine mammals. A monitoring programme was introduced, sampling cod by otter trawling using research vessels. The fish, after capture, were frozen at - 20 degrees C, subsequently thawed and the digestive tract removed and examined for the parasite in 2006. Data from samples taken in 1976, 1980-81, 1986, 1990, 2000 and 2003 were compared statistically with those collected in 2006. The results indicate a decline in the prevalence and mean abundance of E. gadi in 1986 with a minimum in 2000 but increasing gradually in 2003 and 2006. These changes were coincident initially with a decline of oceanic temperature and the entire food web, including capelin (Mallotus villosus), a preferred prey of cod and primary source of E. gadi. The increase in prevalence and mean abundance of the parasite in 2006 were associated with an increase of oceanic temperature and the return of small schools of capelin to offshore areas. Cod older than 4 years harboured a greater abundance of E. gadi than younger fish, while no difference was observed between the sexes. The results suggest that the abundance of E. gadi can be useful as a bioindicator of environmental changes in the north-western Atlantic.

  9. The effect of carbon dioxide on growth of juvenile Atlantic cod Gadus morhua L

    DEFF Research Database (Denmark)

    Moran, Damian; Støttrup, Josianne

    2011-01-01

    A trial was undertaken to investigate how exposure to graded hypercapnia affected the growth performance of juvenile (15-80 g) Atlantic cod. Juveniles were grown at 20‰ salinity and 10 °C for 55 days under three hypercapnic regimes: low (2 ± 0.9 mg L−1 CO2, 0.6 mm Hg, 1000 μatm), medium (8 ± 0.5 mg...... L−1 CO2, 2.8 mm Hg, 3800 μatm) and high CO2 exposure (18 ± 0.2 mg L−1 CO2, 6.3 mm Hg, 8500 μatm). All water quality parameters were within the range of what might normally be considered acceptable for good growth, including the CO2 levels tested. Weight gain, growth rate and condition factor were...... experiments using marine fish species. The test concentrations were recalculated from the reported carbonate chemistry conditions, and indicated that the CO2 concentration effect threshold may have been overestimated in two of these studies. Our study suggests that juvenile Atlantic cod are more susceptible...

  10. Spatiotemporal distribution and composition of mixed stock fishery of Atlantic cod (Gadus morhua) in West Greenlandic waters based on retrospective genetic analysis

    DEFF Research Database (Denmark)

    Bonanomi, Sara; Therkildsen, Nina Overgaard; Hedeholm, Rasmus Berg

    Historical samples of fish are a unique source of DNA to investigate the temporal dynamics of fish population structure and distribution over time. During the last century Atlantic cod (Gadus morhua) stocks have declined dramatically in Greenlandic Waters. Recent genetic investigations have...... in the contribution from the different spawning groups in population mixtures of cod in West Greenland Waters in response to climate variability and fisheries. Performing genetic assignment test, we found stable genetic composition of feeding aggregations over decades in some areas, whereas shifts in composition were...

  11. Correlations of age and growth rate with microbiota composition in Atlantic cod (Gadus morhua) larvae.

    Science.gov (United States)

    Trinh, Ly T T; Bakke, Ingrid; Vadstein, Olav

    2017-08-17

    Little information is available on the link between host development (growth rate and ontogeny) and the composition of the microbiota in fish larvae. This study was carried out to examine potential correlations of microbiota composition with age and growth rate of Atlantic cod larvae. Small and large cod larvae of the same age, representing slow and fast growing individuals, were sampled 10 times during a period of 42 days post hatching (dph), and the composition of the larval microbiota was investigated using a PCR/DGGE (Denaturing Gradient Gel Electrophoresis) strategy. We found significant differences in the intestinal microbiota of small and large larvae of the same age for 4 of the 10 age stages studied. We further found that the variation in the composition of the larval microbiota was more strongly correlated to age than to growth rate for larvae up to 28 dph, whereas for the older larvae growth rate and age was equally correlated to the composition of the microbiota. These results indicate that larval development may structure the microbiota through a change in selection pressure due to host-microbe and microbe-microbe interactions, and that the composition of the microbiota may influence larval development through improved energy gain.

  12. Effect of produced water on feeding and metabolism of Atlantic cod (Gadus morhua)

    Energy Technology Data Exchange (ETDEWEB)

    Volkoff, H.; Parrish, C. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada); Hamoutene, D.; Mabrouk, G.; Samuelson, S.; Mansour, A.; Lee, K. [Fisheries and Oceans Canada, Dartmouth, NS (Canada). Maritimes Region, Ocean Sciences Division

    2007-07-01

    This paper addressed concerns regarding potentially detrimental cumulative effects of waste products from oil industry activities on marine organisms around production sites. The metabolic capacities, feeding and digestive physiology of fish have been shown to change with environmental parameters, which could impact the growth and health status of fish populations. In this study, the effects of produced water (PW) on feeding and metabolism of Atlantic cod was investigated by exposing fish to 0.100 ppm (x 10,000 PW dilution) or 200 ppm (x 500 dilution) of PW for 76 days. Throughout the experiment, food intake and mean weight were monitored. In addition, serum lipids, metabolites and gene expression of a brain appetite regulating factor were measured at the end of the experiment. No significant differences were observed in weight gain or food intake between the 3 groups of fish. Serum metabolites and neuropeptide Y expression remained unchanged between groups. The study is ongoing to complete comparative measurements of whole blood fatty acid profiles in plasma. The preliminary results indicate that feeding and metabolism in cod is not affected by produced water.

  13. An assessment of juvenile Atlantic cod Gadus morhua distribution and growth using diver operated stereo-video surveys.

    Science.gov (United States)

    Elliott, S A M; Ahti, P A; Heath, M R; Turrell, W R; Bailey, D M

    2016-08-01

    Stereo-video scuba transects were conducted during daylight hours from June to September 2013 within a proposed marine protected area (MPA) in the Firth of Clyde, west of Scotland. More juvenile Atlantic cod Gadus morhua of fork length (LF ) range 6-11 cm were observed in substrata containing mixed gravel, including maerl, than in boulder-cobble substrata with high algal cover, or sand with low density seagrass. Community composition was significantly different between substratum types. A decrease in G. morhua abundance was observed over the period of data collection. Over time, mean and variance in G. morhua LF increased, indicating multiple recruitment events. Protecting mixed gravel substrata could be a beneficial management measure to support the survival and recruitment of juvenile G. morhua; other substrata might be important at night given their diel migratory behaviour. Stereo-video cameras provide a useful non-destructive fisheries-independent method to monitor species abundance and length measurements. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  14. Fertilisation and hatching success of Atlantic cod (Gadus morhua) eggs when exposed to various concentrations of produced water

    Energy Technology Data Exchange (ETDEWEB)

    Wong, D.; Lyons, M.; Burridge, L.; Lee, K. [Fisheries and Oceans Canada, Ottawa, ON (Canada)

    2010-07-01

    This study investigated the fertilization and hatching success of Atlantic cod (Gadus morhua) eggs that were exposed to various dilutions of produced water from a natural gas production platform. A control group of eggs was fertilized in sea water without any produced water. Another set of eggs were fertilized in sea water with 4 different concentrations of produced water and held their respective concentrations for 24 hours to evaluate the success of the fertilization. Viable fertilized eggs were transferred to 96 well plates containing fresh sea water and incubated in the dark at approximately 6 degrees C until hatch. Eggs began hatching about 14 days after fertilization (DPF), peaked at about 17 DPF, then finished hatching by 21 DPF. Analysis of PAH content in the diluted produced water showed that at 0.32 percent, 1.08 percent and 3.6 percent concentrations, the fertilization success was greater than or equal to that of the control group. However, for the 12 percent concentration, there were no viable fertilized eggs present after the 24 hour period. Survivability of eggs during sea water incubation was similar for the 0 percent, 0.32 percent and 1.08 percent treatment groups, but egg mortality increased for the 3.60 percent concentration group, to about 61.5 percent mean cumulative mortality at 6 DPF, then remained constant. The mean hatching success for all dilutions was presented.

  15. Growth of juvenile Atlantic cod Gadus morhua in land-based recirculation systems: Effects of feeding regime, photoperiod and diet

    DEFF Research Database (Denmark)

    Fülberth, Michael; Moran, Damian; Jarlbæk, Henrik

    2009-01-01

    fed Diet B and C also grew best under the LD12:11 and LD6:6 feed/photoperiod regimes (SGR range of 2.41–2.46% d− 1). Conversely, fish kept in the LD24:0 feed/photoperiod regime grew relatively slowly irrespective of diet type (SGR range of 2.26–2.32% d− 1). The feed conversion performance of the feed/photoperiod......The combined effect of feeding regime and photoperiod on the growth of juvenile Atlantic cod Gadus morhua in land-based recirculating aquaculture systems (RAS) was examined using three different commercial diets. Fish of 8–10 g were reared in 1 m3 tanks at an initial density of 10 kg m− 3 for 78 d....... Three RAS units were used to simultaneously test three feed/photoperiod regimes that might be encountered in the wild or aquaculture; LightDark (LD) 24:0, LD12:11 (+ 1 h crepuscular periods) and LD6:6 (+ 12 h crepuscular periods). Feed was administered during the light period every 30 min for a 3 min...

  16. Impacts of regular and random noise on the behaviour, growth and development of larval Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Nedelec, Sophie L; Simpson, Stephen D; Morley, Erica L; Nedelec, Brendan; Radford, Andrew N

    2015-10-22

    Anthropogenic noise impacts behaviour and physiology in many species, but responses could change with repeat exposures. As repeat exposures can vary in regularity, identifying regimes with less impact is important for regulation. We use a 16-day split-brood experiment to compare effects of regular and random acoustic noise (playbacks of recordings of ships), relative to ambient-noise controls, on behaviour, growth and development of larval Atlantic cod (Gadus morhua). Short-term noise caused startle responses in newly hatched fish, irrespective of rearing noise. Two days of both regular and random noise regimes reduced growth, while regular noise led to faster yolk sac use. After 16 days, growth in all three sound treatments converged, although fish exposed to regular noise had lower body width-length ratios. Larvae with lower body width-length ratios were easier to catch in a predator-avoidance experiment. Our results demonstrate that the timing of acoustic disturbances can impact survival-related measures during development. Much current work focuses on sound levels, but future studies should consider the role of noise regularity and its importance for noise management and mitigation measures. © 2015 The Authors.

  17. Behavioural changes of Atlantic cod (Gadus morhua) after marine boulder reef restoration: Implications for coastal habitat management and Natura 2000 areas

    DEFF Research Database (Denmark)

    Støttrup, Josianne Gatt; Svendsen, Jon Christian; Stenberg, Claus

    2017-01-01

    While marine reefs are degraded globally, the responses of fish to marine reef restoration remain uncertain, particularly in temperate waters. This study measured the effect of marine boulder reef restoration on the behaviour of Atlantic cod, Gadus morhua L., in a Natura 2000 area using acoustic...... telemetry. Cod were tagged and released in the study area before and after the restoration and tracked continuously for six months. A larger fraction of the released fish remained in the study area after restoration (94%) than before (53%). Moreover, throughout the study period, cod spent significantly more...... hours per day and prolonged their residence time in the study area after the restoration. The study indicates that marine reefs subjected to boulder extraction can be restored and function as favourable cod habitats. Temperate marine boulder reef restoration represents a valuable management tool...

  18. Ocean warming and acidification modulate energy budget and gill ion regulatory mechanisms in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Kreiss, C M; Michael, K; Lucassen, M; Jutfelt, F; Motyka, R; Dupont, S; Pörtner, H-O

    2015-10-01

    Ocean warming and acidification are threatening marine ecosystems. In marine animals, acidification is thought to enhance ion regulatory costs and thereby baseline energy demand, while elevated temperature also increases baseline metabolic rate. Here we investigated standard metabolic rates (SMR) and plasma parameters of Atlantic cod (Gadus morhua) after 3-4 weeks of exposure to ambient and future PCO2 levels (550, 1200 and 2200 µatm) and at two temperatures (10, 18 °C). In vivo branchial ion regulatory costs were studied in isolated, perfused gill preparations. Animals reared at 18 °C responded to increasing CO2 by elevating SMR, in contrast to specimens at 10 °C. Isolated gills at 10 °C and elevated PCO2 (≥1200 µatm) displayed increased soft tissue mass, in parallel to increased gill oxygen demand, indicating an increased fraction of gill in whole animal energy budget. Altered gill size was not found at 18 °C, where a shift in the use of ion regulation mechanisms occurred towards enhanced Na(+)/H(+)-exchange and HCO3 (-) transport at high PCO2 (2200 µatm), paralleled by higher Na(+)/K(+)-ATPase activities. This shift did not affect total gill energy consumption leaving whole animal energy budget unaffected. Higher Na(+)/K(+)-ATPase activities in the warmth might have compensated for enhanced branchial permeability and led to reduced plasma Na(+) and/or Cl(-) concentrations and slightly lowered osmolalities seen at 18 °C and 550 or 2200 µatm PCO2 in vivo. Overall, the gill as a key ion regulation organ seems to be highly effective in supporting the resilience of cod to effects of ocean warming and acidification.

  19. Single and mixture effects of aquatic micropollutants studied in precision-cut liver slices of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Bizarro, Cristina; Eide, Marta; Hitchcock, Daniel J; Goksøyr, Anders; Ortiz-Zarragoitia, Maren

    2016-08-01

    The low concentrations of most contaminants in the aquatic environment individually may not affect the normal function of the organisms on their own. However, when combined, complex mixtures may provoke unexpected effects even at low amounts. Selected aquatic micropollutants such as chlorpyrifos, bis-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoic acid (PFOA) and 17α-ethinylestradiol (EE2) were tested singly and in mixtures at nM to μM concentrations using precision-cut liver slices (PCLS) of Atlantic cod (Gadus morhua). Fish liver is a target organ for contaminants due to its crucial role in detoxification processes. In order to understand the effects on distinct key liver metabolic pathways, transcription levels of various genes were measured, including cyp1a1 and cyp3a, involved in the metabolism of organic compounds, including toxic ones, and the catabolism of bile acids and steroid hormones; cyp7a1, fabp and hmg-CoA, involved in lipid and cholesterol homeostasis; cyp24a1, involved in vitamin D metabolism; and vtg, a key gene in xenoestrogenic response. Only EE2 had significant effects on gene expression in cod liver slices when exposed singly at the concentrations tested. However, when exposed in combinations, effects not detected in single exposure conditions arose, suggesting complex interactions between studied pollutants that could not be predicted from the results of individual exposure scenarios. Thus, the present work highlights the importance of assessing mixtures when describing the toxic effects of micropollutants to fish liver metabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. A moderate increase in ambient temperature modulates the Atlantic cod (Gadus morhua spleen transcriptome response to intraperitoneal viral mimic injection

    Directory of Open Access Journals (Sweden)

    Hori Tiago S

    2012-08-01

    Full Text Available Abstract Background Atlantic cod (Gadus morhua reared in sea-cages can experience large variations in temperature, and these have been shown to affect their immune function. We used the new 20K Atlantic cod microarray to investigate how a water temperature change which, simulates that seen in Newfoundland during the spring-summer (i.e. from 10°C to 16°C, 1°C increase every 5 days impacted the cod spleen transcriptome response to the intraperitoneal injection of a viral mimic (polyriboinosinic polyribocytidylic acid, pIC. Results The temperature regime alone did not cause any significant increases in plasma cortisol levels and only minor changes in spleen gene transcription. However, it had a considerable impact on the fish spleen transcriptome response to pIC [290 and 339 significantly differentially expressed genes between 16°C and 10°C at 6 and 24 hours post-injection (HPI, respectively]. Seventeen microarray-identified transcripts were selected for QPCR validation based on immune-relevant functional annotations. Fifteen of these transcripts (i.e. 88%, including DHX58, STAT1, IRF7, ISG15, RSAD2 and IκBα, were shown by QPCR to be significantly induced by pIC. Conclusions The temperature increase appeared to accelerate the spleen immune transcriptome response to pIC. We found 41 and 999 genes differentially expressed between fish injected with PBS vs. pIC at 10°C and sampled at 6HPI and 24HPI, respectively. In contrast, there were 656 and 246 genes differentially expressed between fish injected with PBS vs. pIC at 16°C and sampled at 6HPI and 24HPI, respectively. Our results indicate that the modulation of mRNA expression of genes belonging to the NF-κB and type I interferon signal transduction pathways may play a role in controlling temperature-induced changes in the spleen’s transcript expression response to pIC. Moreover, interferon effector genes such as ISG15 and RSAD2 were differentially expressed between fish injected with

  1. A moderate increase in ambient temperature modulates the Atlantic cod (Gadus morhua) spleen transcriptome response to intraperitoneal viral mimic injection

    Science.gov (United States)

    2012-01-01

    Background Atlantic cod (Gadus morhua) reared in sea-cages can experience large variations in temperature, and these have been shown to affect their immune function. We used the new 20K Atlantic cod microarray to investigate how a water temperature change which, simulates that seen in Newfoundland during the spring-summer (i.e. from 10°C to 16°C, 1°C increase every 5 days) impacted the cod spleen transcriptome response to the intraperitoneal injection of a viral mimic (polyriboinosinic polyribocytidylic acid, pIC). Results The temperature regime alone did not cause any significant increases in plasma cortisol levels and only minor changes in spleen gene transcription. However, it had a considerable impact on the fish spleen transcriptome response to pIC [290 and 339 significantly differentially expressed genes between 16°C and 10°C at 6 and 24 hours post-injection (HPI), respectively]. Seventeen microarray-identified transcripts were selected for QPCR validation based on immune-relevant functional annotations. Fifteen of these transcripts (i.e. 88%), including DHX58, STAT1, IRF7, ISG15, RSAD2 and IκBα, were shown by QPCR to be significantly induced by pIC. Conclusions The temperature increase appeared to accelerate the spleen immune transcriptome response to pIC. We found 41 and 999 genes differentially expressed between fish injected with PBS vs. pIC at 10°C and sampled at 6HPI and 24HPI, respectively. In contrast, there were 656 and 246 genes differentially expressed between fish injected with PBS vs. pIC at 16°C and sampled at 6HPI and 24HPI, respectively. Our results indicate that the modulation of mRNA expression of genes belonging to the NF-κB and type I interferon signal transduction pathways may play a role in controlling temperature-induced changes in the spleen’s transcript expression response to pIC. Moreover, interferon effector genes such as ISG15 and RSAD2 were differentially expressed between fish injected with pIC at 10°C vs. 16

  2. Sex steroids differentially regulate fshb, lhb and gnrhr expression in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    von Krogh, Kristine; Bjørndal, Gunnveig Toft; Nourizadeh-Lillabadi, Rasoul; Hodne, Kjetil; Ropstad, Erik; Haug, Trude M; Weltzien, Finn-Arne

    2017-11-01

    Depending on the stage of gonad maturation, as well as other factors, gonadal steroids can exert either a positive or negative feedback at the brain and pituitary level. While this has been demonstrated in many teleost species, little is known about the nature of steroid feedback in Gadiform fish. Using an optimized in vitro model system of the Atlantic cod pituitary, the present study investigated the potential effects of two physiologically relevant doses of estradiol, testosterone (TS) or dihydrotestosterone (DHTS) on cell viability and gene expression of gonadotropin subunits (fshb/lhb) and two suggested reproduction-relevant gonadotropin-releasing hormone receptors (gnrhr1b/gnrhr2a) during three stages of sexual maturity. In general, all steroids stimulated cell viability in terms of metabolic activity and membrane integrity. Furthermore, all steroids affected fshb expression, with the effect depending on both the specific steroid, dose and maturity status. Conversely, only DHTS exposure affected lhb levels, and this occurred only during the spawning season. Using single-cell qPCR, co-transcription of gnrhr1b and gnrhr2a was confirmed to both fshb- and lhb- expressing gonadotropes, with gnrhr2a being the most prominently expressed isoform. While steroid exposure had no effect on gnrhr1b expression, all steroids affected gnrhr2a transcript levels in at least one maturity stage. These and previous results from our group point to Gnrhr2a as the main modulator of gonadotropin regulation in cod and that regulation of its gene expression level might function as a direct mechanism for steroid feedback at the pituitary level. © 2017 Society for Reproduction and Fertility.

  3. Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua

    Directory of Open Access Journals (Sweden)

    Mittelholzer Christian

    2009-12-01

    Full Text Available Abstract Background Marine fishes have been shown to display low levels of genetic structuring and associated high levels of gene flow, suggesting shallow evolutionary trajectories and, possibly, limited or lacking adaptive divergence among local populations. We investigated variation in 98 gene-associated single nucleotide polymorphisms (SNPs for evidence of selection in local populations of Atlantic cod (Gadus morhua L. across the species distribution. Results Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread and complex, i.e. outlier loci were generally not only associated with one of a few divergent local populations. Even on a limited geographical scale between the proximate North Sea and Baltic Sea populations four loci displayed evidence of adaptive evolution. Temporal genome scan analysis applied to DNA from archived otoliths from a Faeroese population demonstrated stability of the intra-population variation over 24 years. An exploratory landscape genetic analysis was used to elucidate potential effects of the most likely environmental factors responsible for the signatures of local adaptation. We found that genetic variation at several of the outlier loci was better correlated with temperature and/or salinity conditions at spawning grounds at spawning time than with geographic distance per se. Conclusion These findings illustrate that adaptive population divergence may indeed be prevalent despite seemingly high levels of gene flow, as found in most marine fishes. Thus, results have important implications for our understanding of the interplay of

  4. Genomic signatures of local directional selection in a high gene flow marine organism; the Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Nielsen, Einar E; Hemmer-Hansen, Jakob; Poulsen, Nina A; Loeschcke, Volker; Moen, Thomas; Johansen, Torild; Mittelholzer, Christian; Taranger, Geir-Lasse; Ogden, Rob; Carvalho, Gary R

    2009-12-01

    Marine fishes have been shown to display low levels of genetic structuring and associated high levels of gene flow, suggesting shallow evolutionary trajectories and, possibly, limited or lacking adaptive divergence among local populations. We investigated variation in 98 gene-associated single nucleotide polymorphisms (SNPs) for evidence of selection in local populations of Atlantic cod (Gadus morhua L.) across the species distribution. Our global genome scan analysis identified eight outlier gene loci with very high statistical support, likely to be subject to directional selection in local demes, or closely linked to loci under selection. Likewise, on a regional south/north transect of central and eastern Atlantic populations, seven loci displayed strongly elevated levels of genetic differentiation. Selection patterns among populations appeared to be relatively widespread and complex, i.e. outlier loci were generally not only associated with one of a few divergent local populations. Even on a limited geographical scale between the proximate North Sea and Baltic Sea populations four loci displayed evidence of adaptive evolution. Temporal genome scan analysis applied to DNA from archived otoliths from a Faeroese population demonstrated stability of the intra-population variation over 24 years. An exploratory landscape genetic analysis was used to elucidate potential effects of the most likely environmental factors responsible for the signatures of local adaptation. We found that genetic variation at several of the outlier loci was better correlated with temperature and/or salinity conditions at spawning grounds at spawning time than with geographic distance per se. These findings illustrate that adaptive population divergence may indeed be prevalent despite seemingly high levels of gene flow, as found in most marine fishes. Thus, results have important implications for our understanding of the interplay of evolutionary forces in general, and for the conservation of

  5. A review of the evidence for genetic structure of cod ( Gadus morhua ) populations in the NW Atlantic and population affinities of larval cod off Newfoundland and the Gulf of St. Lawrence

    DEFF Research Database (Denmark)

    Ruzzante, D.E.; Taggart, C.T.; Cook, D.

    1999-01-01

    We review our recent studies on the genetic structure of Atlantic cod (Gadus morhua) populations in the NW Atlantic. Our conclusions are based on knowledge of polymorphism at microsatellite DNA loci combined with known aspects of cod biology and ecology and with known oceanographic features...... in the NW Atlantic. Three case studies illustrate genetic heterogeneity between cod populations at the meso- and large- scales of coastal embayments and offshore banks and at the small-scale of oceanographic features. Our results generally highlight the importance of combining genetic with physiological......, ecological, and oceanographic information, when assessing the genetic structure of highly abundant, widely distributed, and high gene-flow marine fish species. We highlight the role that oceanographic features (e.g., gyre-like systems) and known spatio-temporal differences in spawning time may play...

  6. Will you swim into my parlour? In situ observations of Atlantic cod (Gadus morhua) interactions with baited pots, with implications for gear design.

    Science.gov (United States)

    Meintzer, Phillip; Walsh, Philip; Favaro, Brett

    2017-01-01

    Pots (also known as traps) are baited fishing gears widely used in commercial fisheries, and are being considered as a tool for harvesting Atlantic cod (Gadus morhua) in Newfoundland and Labrador, Canada. Pots produce lower environmental impacts than many other fishing gears, but they will only be a viable fishing strategy if they are efficient and selective at catching their target species. To study the behaviour of cod in and around pots, and how those behaviours affect pot efficiency, we used long-duration underwater video cameras to assess two models of cod pot deployed in the nearshore waters of Fogo Island, NL. We examined the number of cod that approached the pot, the number and proportion that successfully completed entries into the pot openings, and the number that exited, and related these factors to the direction of water movement. We observed very few entry attempts relative to the number of approaches by cod, and only 22% of all entry attempts were successful. We observed that 50% of approaches, 70% of entry attempts, and 73% of successful entrances occurred against the current, and 25% of cod were able to exit the pot following capture. Based on our observations, we suggest that future cod pots should have a greater number of entrances, or a mechanism to ensure that entrances rotate in line with the current, in order to maximize their catch efficiency for cod.

  7. Will you swim into my parlour? In situ observations of Atlantic cod (Gadus morhua interactions with baited pots, with implications for gear design

    Directory of Open Access Journals (Sweden)

    Phillip Meintzer

    2017-02-01

    Full Text Available Pots (also known as traps are baited fishing gears widely used in commercial fisheries, and are being considered as a tool for harvesting Atlantic cod (Gadus morhua in Newfoundland and Labrador, Canada. Pots produce lower environmental impacts than many other fishing gears, but they will only be a viable fishing strategy if they are efficient and selective at catching their target species. To study the behaviour of cod in and around pots, and how those behaviours affect pot efficiency, we used long-duration underwater video cameras to assess two models of cod pot deployed in the nearshore waters of Fogo Island, NL. We examined the number of cod that approached the pot, the number and proportion that successfully completed entries into the pot openings, and the number that exited, and related these factors to the direction of water movement. We observed very few entry attempts relative to the number of approaches by cod, and only 22% of all entry attempts were successful. We observed that 50% of approaches, 70% of entry attempts, and 73% of successful entrances occurred against the current, and 25% of cod were able to exit the pot following capture. Based on our observations, we suggest that future cod pots should have a greater number of entrances, or a mechanism to ensure that entrances rotate in line with the current, in order to maximize their catch efficiency for cod.

  8. Molecular Evidence that Only Two Opsin Subfamilies, the Blue Light- (SWS2) and Green Light-Sensitive (RH2), Drive Color Vision in Atlantic Cod (Gadus morhua)

    Science.gov (United States)

    Søviknes, Anne Mette; Drivenes, Øyvind; Helvik, Jon Vidar

    2014-01-01

    Teleosts show a great variety in visual opsin complement, due to both gene duplication and gene loss. The repertoire ranges from one subfamily of visual opsins (scotopic vision) including rod opsin only retinas seen in many deep-sea species to multiple subfamilies of visual opsins in some pelagic species. We have investigated the opsin repertoire of Atlantic cod (Gadus morhua) using information in the recently sequenced cod genome and found that despite cod not being a deep sea species it lacks visual subfamilies sensitive towards the most extreme parts of the light spectra representing UV and red light. Furthermore, we find that Atlantic cod has duplicated paralogs of both blue-sensitive SWS2 and green-sensitive RH2 subfamilies, with members belonging to each subfamily linked in tandem within the genome (two SWS2-, and three RH2A genes, respectively). The presence of multiple cone opsin genes indicates that there have been duplication events in the cod ancestor SWS2 and RH2 opsins producing paralogs that have been retained in Atlantic. Our results are supported by expressional analysis of cone opsins, which further revealed an ontogenetic change in the array of cone opsins expressed. These findings suggest life stage specific programs for opsin regulation which could be linked to habitat changes and available light as the larvae is transformed into an early juvenile. Altogether we provide the first molecular evidence for color vision driven by only two families of cone opsins due to gene loss in a teleost. PMID:25551396

  9. Molecular evidence that only two opsin subfamilies, the blue light- (SWS2 and green light-sensitive (RH2, drive color vision in Atlantic cod (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Ragnhild Valen

    Full Text Available Teleosts show a great variety in visual opsin complement, due to both gene duplication and gene loss. The repertoire ranges from one subfamily of visual opsins (scotopic vision including rod opsin only retinas seen in many deep-sea species to multiple subfamilies of visual opsins in some pelagic species. We have investigated the opsin repertoire of Atlantic cod (Gadus morhua using information in the recently sequenced cod genome and found that despite cod not being a deep sea species it lacks visual subfamilies sensitive towards the most extreme parts of the light spectra representing UV and red light. Furthermore, we find that Atlantic cod has duplicated paralogs of both blue-sensitive SWS2 and green-sensitive RH2 subfamilies, with members belonging to each subfamily linked in tandem within the genome (two SWS2-, and three RH2A genes, respectively. The presence of multiple cone opsin genes indicates that there have been duplication events in the cod ancestor SWS2 and RH2 opsins producing paralogs that have been retained in Atlantic. Our results are supported by expressional analysis of cone opsins, which further revealed an ontogenetic change in the array of cone opsins expressed. These findings suggest life stage specific programs for opsin regulation which could be linked to habitat changes and available light as the larvae is transformed into an early juvenile. Altogether we provide the first molecular evidence for color vision driven by only two families of cone opsins due to gene loss in a teleost.

  10. Molecular evidence that only two opsin subfamilies, the blue light- (SWS2) and green light-sensitive (RH2), drive color vision in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Valen, Ragnhild; Edvardsen, Rolf Brudvik; Søviknes, Anne Mette; Drivenes, Øyvind; Helvik, Jon Vidar

    2014-01-01

    Teleosts show a great variety in visual opsin complement, due to both gene duplication and gene loss. The repertoire ranges from one subfamily of visual opsins (scotopic vision) including rod opsin only retinas seen in many deep-sea species to multiple subfamilies of visual opsins in some pelagic species. We have investigated the opsin repertoire of Atlantic cod (Gadus morhua) using information in the recently sequenced cod genome and found that despite cod not being a deep sea species it lacks visual subfamilies sensitive towards the most extreme parts of the light spectra representing UV and red light. Furthermore, we find that Atlantic cod has duplicated paralogs of both blue-sensitive SWS2 and green-sensitive RH2 subfamilies, with members belonging to each subfamily linked in tandem within the genome (two SWS2-, and three RH2A genes, respectively). The presence of multiple cone opsin genes indicates that there have been duplication events in the cod ancestor SWS2 and RH2 opsins producing paralogs that have been retained in Atlantic. Our results are supported by expressional analysis of cone opsins, which further revealed an ontogenetic change in the array of cone opsins expressed. These findings suggest life stage specific programs for opsin regulation which could be linked to habitat changes and available light as the larvae is transformed into an early juvenile. Altogether we provide the first molecular evidence for color vision driven by only two families of cone opsins due to gene loss in a teleost.

  11. Functional genomic analysis of the response of Atlantic cod (Gadus morhua) spleen to the viral mimic polyriboinosinic polyribocytidylic acid (pIC).

    Science.gov (United States)

    Rise, Matthew L; Hall, Jennifer; Rise, Marlies; Hori, Tiago; Gamperl, A Kurt; Kimball, Jennifer; Hubert, Sophie; Bowman, Sharen; Johnson, Stewart C

    2008-01-01

    In order to improve our understanding of how Atlantic cod (Gadus morhua) respond to viruses, we characterized immune-related gene expression in spleen tissues following stimulation with a synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid (pIC). We used reciprocal suppression subtractive hybridization (SSH) cDNA libraries and quantitative RTPCR (QPCR) to identify and quantify pIC-responsive transcripts. A total of 3874 expressed sequence tags (ESTs) were generated from SSH libraries enriched for genes responsive to pIC. Thirteen immune-relevant genes from the libraries were subjected to QPCR. Genes confirmed as up-regulated by pIC included interferon stimulated gene 15, a small inducible cytokine, interferon regulatory factors (1, 7, and 10), MHC class I, viperin, and ATP-dependent helicase LGP2. Alpha-1-microglobulin (bikunin) was down-regulated, suggesting that pIC may suppress the acute phase response. Since the SSH libraries built for this study identified genes involved in the antiviral response, they are important resources for studying the responses of Atlantic cod to viruses. Evidence is provided for the existence of a RIG-I-like RNA helicase viral recognition pathway in Atlantic cod. Taken together, our data show that Atlantic cod can recognize double-stranded RNA and mount a rapid and potent interferon pathway response that is similar to that observed in other fish species and higher vertebrates.

  12. Global transcriptome analysis of Atlantic cod (Gadus morhua) liver after in vivo methylmercury exposure suggests effects on energy metabolism pathways.

    Science.gov (United States)

    Yadetie, Fekadu; Karlsen, Odd Andre; Lanzén, Anders; Berg, Karin; Olsvik, Pål; Hogstrand, Christer; Goksøyr, Anders

    2013-01-15

    Methylmercury (MeHg) is a widely distributed contaminant polluting many aquatic environments, with health risks to humans exposed mainly through consumption of seafood. The mechanisms of toxicity of MeHg are not completely understood. In order to map the range of molecular targets and gain better insights into the mechanisms of toxicity, we prepared Atlantic cod (Gadus morhua) 135k oligonucleotide arrays and performed global analysis of transcriptional changes in the liver of fish treated with MeHg (0.5 and 2 mg/kg of body weight) for 14 days. Inferring from the observed transcriptional changes, the main pathways significantly affected by the treatment were energy metabolism, oxidative stress response, immune response and cytoskeleton remodeling. Consistent with known effects of MeHg, many transcripts for genes in oxidative stress pathways such as glutathione metabolism and Nrf2 regulation of oxidative stress response were differentially regulated. Among the differentially regulated genes, there were disproportionate numbers of genes coding for enzymes involved in metabolism of amino acids, fatty acids and glucose. In particular, many genes coding for enzymes of fatty acid beta-oxidation were up-regulated. The coordinated effects observed on many transcripts coding for enzymes of energy pathways may suggest disruption of nutrient metabolism by MeHg. Many transcripts for genes coding for enzymes in the synthetic pathways of sulphur containing amino acids were also up-regulated, suggesting adaptive responses to MeHg toxicity. By this toxicogenomics approach, we were also able to identify many potential biomarker candidate genes for monitoring environmental MeHg pollution. These results based on changes on transcript levels, however, need to be confirmed by other methods such as proteomics. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Biological effects of polycyclic aromatic hydrocarbons (PAH) and their first metabolic products in in vivo exposed Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Pampanin, Daniela M; Le Goff, Jeremie; Skogland, Karianne; Marcucci, Cristian R; Øysæd, Kjell Birger; Lorentzen, Marianne; Jørgensen, Kåre B; Sydnes, Magne O

    2016-01-01

    The monitoring of the presence of polycyclic aromatic hydrocarbons (PAH) in the aquatic environment is a worldwide activity since some of these compounds are well-established carcinogens and mutagens. Contaminants in this class are in fact regarded as priority hazardous substances for environmental pollution (Water Framework Directive 2000/60/EC). In this study, Atlantic cod (Gadus morhua) was selected to assess in vivo effects of two PAH and their first metabolic products, namely, the corresponding trans-dihydrodiols, using biological markers. Fish were exposed for 1 wk to a single PAH (naphthalene or chrysene) and its synthetic metabolites ((1R,2R)-1,2-dihydronaphthalene-1,2-diol and (1R,2R)-1,2-dihydrochrysene-1,2-diol) by intraperitoneal injection in a continuous seawater flow system. After exposure, PAH metabolism including PAH metabolites in bile and ethoxyresorufin O-deethylase (EROD) activity, oxidative stress glutathione S-transferases (GST) and catalase (CAT) activities, and genotoxicity such as DNA adducts were evaluated, as well as general health conditions including condition index (CI), hepatosomatic index (HSI), and gonadosomatic index (GSI). PAH metabolite values were low and not significantly different when measured with the fixed-wavelength fluorescence screening method, while the gas chromatography-mass spectroscopy (GC-MS) method showed an apparent dose response in fish exposed to naphthalene. DNA adduct levels ≥0.16 × 10(-8) relative adduct level (RAL) were detected. It should be noted that 0.16 × 10(-8) RAL is considered the maximal acceptable background level for this species. The other biomarkers activities of catalase, GST, and EROD did not display a particular compound- or dose-related response. The GSI values were significantly lower in some chrysene- and in both naphthalene- and naphthalene diol-exposed groups compared to control.

  14. Sex differentiation in Atlantic cod (Gadus morhua L.: morphological and gene expression studies

    Directory of Open Access Journals (Sweden)

    Haugen Trine

    2012-06-01

    Full Text Available Abstract Background In differentiated gonochoristic species, a bipotential gonad develops into an ovary or testis during sex differentiation. Knowledge about this process is necessary to improve methods for masculinizing genetically female Atlantic cod for the subsequent purpose of producing all-female populations. Methods Gonads were examined histologically in juveniles from 14 to 39 mm total body length (TL. Number and size of germ cells were determined in a subset of the samples. Relevant genes were cloned, and mRNA levels determined by qPCR of amh, cyp19a1a; dax1 (nr0b2; shp (nr0b2a and sox9b in a mixed-sex and an all-female population ranging from 12–49 mm TL. Results Individuals between 14–20 mm TL could be separated in two subgroups based on gonad size and germ cell number. Ovarian cavity formation was observed in some individuals from 18–20 mm TL. The mixed sex population displayed bimodal expression patterns as regards cyp19a1a (starting at 12 mm TL and amh (starting at 20 mm TL mRNA levels. After approximately 30 mm TL, cyp19a1a and amh displayed a gradual increase in both sexes. No apparent, sex-dependent expression patterns were found for dax1, shp or sox9b transcripts. However, shp levels were high until the larvae reached around 35 mm TL and then dropped to low levels, while dax1 remained low until 35 mm TL, and then increased sharply. Conclusions The morphological sex differentiation in females commenced between 14–20 mm TL, and ovarian cavities were evident by 18–20 mm TL. Testis development occurred later, and was morphologically evident after 30 mm TL. This pattern was corroborated with sexually dimorphic expression patterns of cyp19a1a from 12–13 mm TL, and a male-specific increase in amh from 20 mm TL.

  15. Life-history evolution and elevated natural mortality in a population of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Swain, Douglas P

    2011-01-01

    Fisheries-induced evolution has been hypothesized to delay the recovery of collapsed fish stocks through effects on their productivity. The cod stock in the southern Gulf of St. Lawrence (SGSL) collapsed in the early 1990s and has shown no recovery since then, due mainly to high natural mortality of adult cod. Age and size at maturation of SGSL cod decreased sharply over time in cohorts produced in the 1950s and 1960s, likely reflecting an evolutionary response to intensified fishing, and have remained low since then, despite severe reductions in fishing mortality over the past 15 years. A predicted consequence of early maturation is increased natural mortality due to higher costs to reproduction. Early maturation may be a cause of increases in natural mortality of SGSL cod in the 1970s but does not appear to be related to the much larger increases since then. Instead, the current high natural mortality of SGSL cod appears to be primarily a cause, rather than a consequence, of the continued early maturation in this population, now replacing fishing mortality as the agent of selection favouring early maturity. This striking example of the failure to reverse fisheries-induced evolution by relaxing fishing pressure emphasizes the need for management strategies that minimize the chances of harvest-induced genetic change.

  16. Identification and molecular cloning of Atlantic cod (Gadus morhua) activating transcription factor 3 (ATF3) transcript and its induction in spleen following intraperitoneal polyriboinosinic polyribocytidylic acid injection.

    Science.gov (United States)

    Feng, Charles Y; Rise, Matthew L

    2011-09-01

    Activating transcription factor 3 (ATF3) participates in cellular processes to adapt to various extra- and intra-cellular changes including the modulation of immunity to prevent uncontrolled immune responses to pathogens. In teleost fishes, the involvement of ATF3 in immune response has not been documented. In this study, the putative Atlantic cod (Gadus morhua) ATF3 transcript was identified by performing rapid amplification of cDNA ends (RACE) based on unknown expressed sequence tags (ESTs) that are potentially inducible by polyriboinosinic polyribocytidylic acid (pIC, a synthetic double-stranded RNA viral mimic) in Atlantic cod. ATF3-like ESTs were the most abundant unknown transcript (i.e. lacking significant BLAST hits) generated from a previously constructed cDNA library enriched for pIC inducible transcripts in Atlantic cod spleen. The full-length cDNA of cod ATF3 consists of 2329 nucleotides with an open reading frame (ORF) of 735 bp encoding 244 amino acids. The deduced amino acid sequence of Atlantic cod ATF3 shares over 45% identity with its putative orthologs from other vertebrates. In addition, the presence of a conserved basic region leucine zipper (bZIP) domain in the deduced Atlantic cod ATF3-like protein further supports its identity as an ATF3 homolog. In the spleen of Atlantic cod challenged with intraperitoneal (IP) injections of pIC, the time-course transcript expression of ATF3 was studied using quantitative reverse transcription-polymerase chain reaction (QPCR). At 6 h following the pIC injection, the relative expression level of ATF3 mRNA was significantly up-regulated in comparison to a pre-injected control (61.9-fold) and its time-matched saline-injected control (97.3-fold). At 24 h following the pIC injection, the mRNA expression level of cod ATF3 had subsided and was no longer significantly different from its pre-injected control, but significantly higher (1.88-fold) than its time-matched saline-injected control. Collectively, these

  17. Evolutionary redesign of the Atlantic cod (Gadus morhua L.) Toll-like receptor repertoire by gene losses and expansions.

    Science.gov (United States)

    Solbakken, Monica H; Tørresen, Ole K; Nederbragt, Alexander J; Seppola, Marit; Gregers, Tone F; Jakobsen, Kjetill S; Jentoft, Sissel

    2016-04-29

    Genome sequencing of the teleost Atlantic cod demonstrated loss of the Major Histocompatibility Complex (MHC) class II, an extreme gene expansion of MHC class I and gene expansions and losses in the innate pattern recognition receptor (PRR) family of Toll-like receptors (TLR). In a comparative genomic setting, using an improved version of the genome, we characterize PRRs in Atlantic cod with emphasis on TLRs demonstrating the loss of TLR1/6, TLR2 and TLR5 and expansion of TLR7, TLR8, TLR9, TLR22 and TLR25. We find that Atlantic cod TLR expansions are strongly influenced by diversifying selection likely to increase the detectable ligand repertoire through neo- and subfunctionalization. Using RNAseq we find that Atlantic cod TLRs display likely tissue or developmental stage-specific expression patterns. In a broader perspective, a comprehensive vertebrate TLR phylogeny reveals that the Atlantic cod TLR repertoire is extreme with regards to losses and expansions compared to other teleosts. In addition we identify a substantial shift in TLR repertoires following the evolutionary transition from an aquatic vertebrate (fish) to a terrestrial (tetrapod) life style. Collectively, our findings provide new insight into the function and evolution of TLRs in Atlantic cod as well as the evolutionary history of vertebrate innate immunity.

  18. Melanin-concentrating hormone (MCH) and gonadotropin-releasing hormones (GnRH) in Atlantic cod, Gadus morhua: tissue distributions, early ontogeny and effects of fasting.

    Science.gov (United States)

    Tuziak, Sarah M; Volkoff, Hélène

    2013-12-01

    Melanin-concentrating hormone (MCH) is classically known for its role in regulating teleost fish skin color change for environmental adaptation. Recent evidence suggests that MCH also has appetite-stimulating properties. The gonadotropin-releasing hormone (GnRH) peptide family has dual roles in endocrine control of reproduction and energy status in fish. Atlantic cod (Gadus morhua) are a commercially important aquaculture species inhabiting the shores of Atlantic Canada. In this study, we examine MCH and GnRH transcript expression profiles during early development as well as in central and peripheral tissues and quantify juvenile Atlantic cod MCH and GnRH hypothalamic mRNA expressions following food deprivation. MCH and GnRH3 cDNAs are maternally deposited into cod eggs, while MCH has variable expression throughout early development. GnRH2 and GnRH3 mRNAs "turn-on" during mid-segmentation once the brain is fully developed. For both MCH and GnRH, highest expression appears during the exogenous feeding stages, perhaps supporting their functions as appetite regulators during early development. MCH and GnRH transcripts are found in brain regions related to appetite regulation (telencephalon/preoptic area, optic tectum/thalamus, hypothalamus), as well as the pituitary gland and the stomach, suggesting a peripheral function in food intake regulation. Atlantic cod MCH mRNA is upregulated during fasting, while GnRH2 and GnRH3 transcripts do not appear to be influenced by food deprivation. In conclusion, MCH might be involved in stimulating food intake in juvenile Atlantic cod, while GnRHs may play a more significant role in appetite regulation during early development. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Precision-cut liver slices of Atlantic cod (Gadus morhua): an in vitro system for studying the effects of environmental contaminants.

    Science.gov (United States)

    Eide, M; Karlsen, O A; Kryvi, H; Olsvik, P A; Goksøyr, A

    2014-08-01

    The Atlantic cod (Gadus morhua) is an economically important species commonly consumed by humans. The widespread distribution of cod in the North Atlantic Ocean makes it vulnerable to effluents from human activities, such as coastal industries and offshore petroleum exploration. It has been demonstrated that many effluents have adverse effects on cod reproduction and health, e.g. by disrupting endocrine signaling pathways. The liver, expressing important components of the biotransformation and the endocrine system, is one of the main target organs. Thus, reliable and reproducible in vitro systems of the liver are important for studying effects of environmental contaminants. The aim of this study was to investigate precision-cut liver slices (PCLS) as an alternative in vitro system for toxicological studies of the Atlantic cod liver. Slices of 8 mm in diameter and 250 μm thickness were prepared and cultivated from immature cod. Several analyses to measure the liver slice viability were performed: enzyme assays, histology, and morphometric analysis, all confirming cell viability for up to 72 h in culture. The liver slices were also exposed to two well-known model environmental contaminants, β-naphthoflavone (BNF) and 17α-ethynylestradiol (EE2), representing established agonists for the aryl hydrocarbon receptor (AHR) and the estrogen receptor (ER), respectively. The results showed increased transcription of the target genes cytochrome P450 1A (CYP1A) and vitellogenin (VTG), both well-established biomarkers for exposure of fish to the selected compounds. In conclusion, PCLS is a promising in vitro system for toxicological studies of cod liver cells. The liver slices are viable in culture for several days and respond to environmental contaminants in a dose- and time-specific manner. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Correlation between microbiota and growth in Mangrove Killifish (Kryptolebias marmoratus) and Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Forberg, Torunn; Sjulstad, Eli Bjørnø; Bakke, Ingrid; Olsen, Yngvar; Hagiwara, Atsushi; Sakakura, Yoshitaka; Vadstein, Olav

    2016-02-15

    The vertebrate gut is host to large communities of bacteria, and one of the beneficial contributions of this commensal gut microbiota is the increased nutritional gain from feed components that the host cannot degrade on its own. Fish larvae of similar age and under the same rearing conditions often diverge with regards to growth. The underlying reasons for this could be differences in genetic background, feeding behavior or digestive capacity. Both feeding behavior and digestion can be influenced by differences in the microbiota. To investigate possible correlations between the size of fish larvae and their gut microbiota, we analyzed the microbiota small and large genetically homogenous killifish and genetically heterogeneous cod larvae by Bray-Curtis Similarity measures of 16S DNA DGGE patterns. A significant difference in richness (p = 0.037) was observed in the gut microbiota of small and large killifish, but the overall gut microbiota was not found to be significantly different (p = 0.13), indicating strong genetic host selection on microbiota composition at the time of sampling. The microbiota of small and large cod larvae was significantly different with regards to evenness and diversity (p = 0.0001), and a strong correlation between microbiota and growth was observed.

  1. Temperature, paternity and asynchronous hatching influence early developmental characteristics of larval Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Dahlke, Flemming T.; Butts, Ian A.E.

    2014-01-01

    or if they hatched at the end of the hatching period at a specific temperature. Differences in larval morphometrics among temperatures for early hatching larvae decreased or even reversed for later hatching larvae. In light of anticipated global climate change, the present study on cod provides further insight...... (LN), yolk-sac area (AY), and deformities. Larvae hatching on a given day were incubated at the same temperature and sampled at 4days post-hatch (DPH) for growth, yolk utilization rate (YUR) and efficiency (YUE). The mean±SE duration of the hatching window decreased with increasing temperature in both......Offspring, especially during early development, are influenced by both intrinsic properties endowed to them by their parents, extrinsic environmental factors as well as the interplay between genes and the environment. We investigated the effects of paternity (P), temperature (T), and asynchronous...

  2. Changes in natural mortality of Atlantic cod ( Gadus morhua) on Eastern Georges Bank

    Science.gov (United States)

    Wang, Yanjun

    2016-10-01

    The assessment of Eastern Georges Bank cod with the assumption of a constant natural mortality of 0.2 has over-estimated stock productivity, resulting in a severe retrospective pattern since the late 2000s. Comparing relative exploitation rate (ratio of fishery catch at age to survey abundance indices at age) with total mortality calculated from the age distribution in surveys indicated a conflict when constant natural mortality was assumed. This inconsistency implies an increase in natural mortality since the mid-1990s. In this paper, natural mortality estimated by Virtual Population Analysis (VPA) indicated that natural mortality for this stock has increased to 0.8 since the mid-1990s for ages 6+. Potential factors contributing to this elevated natural mortality, including poor fish conditions and increased losses due to seal predation were discussed.

  3. Differential Survival among Batches of Atlantic Cod (Gadus morhua L. from Fertilisation through to Post-Metamorphosis.

    Directory of Open Access Journals (Sweden)

    Petra E Petersen

    Full Text Available Aquaculture production of cod has decreased from over 20,000 tonnes in 2009 to less than 2,000 tonnes in 2014 and the industry faces many challenges, one of which is high and unpredictably variable mortality rates in the early life stages. Hence, full-cycle farming with hatchery produced juveniles is still considered unprofitable compared to fisheries and on-growing of wild cod. In the present study, potential batch differences in progeny survival of wild-caught, hatchery-spawned Faroe Bank cod (Gadus morhua L. were investigated at two defined periods during early life history; i the embryo stage (60 day degrees post fertilisation and ii the fry stage (110 days post hatch, post metamorphosis. The fry stage experiment was conducted in three replicates (N = 300 per replicate, and a panel of three polymorphic microsatellite markers was used for parental analysis. Mean survival rate at the embryo stage was 69% (± 20% SD. Survival was positively associated with egg diameter (P < 0.01, explaining 90% of the variation in egg survival rates. The data were too scarce to conclude either way concerning a possible correlation between survival rates between the two periods (P < 0.10. Offspring from three batches (from a total of eight dominated in the fry stage, contributing over 90% of the progeny, and results were consistent over all three replicate tanks. The skewed batch representation observed may be of relevance to the effective management of selective breeding programmes for cod.

  4. Differential Survival among Batches of Atlantic Cod (Gadus morhua L.) from Fertilisation through to Post-Metamorphosis.

    Science.gov (United States)

    Petersen, Petra E; Penman, David J; Dahle, Geir; Patursson, Øystein; Taggart, John B

    2016-01-01

    Aquaculture production of cod has decreased from over 20,000 tonnes in 2009 to less than 2,000 tonnes in 2014 and the industry faces many challenges, one of which is high and unpredictably variable mortality rates in the early life stages. Hence, full-cycle farming with hatchery produced juveniles is still considered unprofitable compared to fisheries and on-growing of wild cod. In the present study, potential batch differences in progeny survival of wild-caught, hatchery-spawned Faroe Bank cod (Gadus morhua L.) were investigated at two defined periods during early life history; i) the embryo stage (60 day degrees post fertilisation) and ii) the fry stage (110 days post hatch), post metamorphosis. The fry stage experiment was conducted in three replicates (N = 300 per replicate), and a panel of three polymorphic microsatellite markers was used for parental analysis. Mean survival rate at the embryo stage was 69% (± 20% SD). Survival was positively associated with egg diameter (P < 0.01), explaining 90% of the variation in egg survival rates. The data were too scarce to conclude either way concerning a possible correlation between survival rates between the two periods (P < 0.10). Offspring from three batches (from a total of eight) dominated in the fry stage, contributing over 90% of the progeny, and results were consistent over all three replicate tanks. The skewed batch representation observed may be of relevance to the effective management of selective breeding programmes for cod.

  5. Characterization and expression analyses of five interferon regulatory factor transcripts (Irf4a, Irf4b, Irf7, Irf8, Irf10) in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Inkpen, Sabrina M; Hori, Tiago S; Gamperl, A Kurt; Nash, Gordon W; Rise, Matthew L

    2015-05-01

    The interferon regulatory factor (IRF) family of genes encodes a group of transcription factors that have important roles not only in regulating the expression of Type I interferons (IFNs) and other genes in the IFN pathway, but also in growth, development and the regulation of oncogenesis. In this study, several IRF family members (Irf4a, Irf4b, Irf7, Irf8, Irf10) in Atlantic cod (Gadus morhua) were characterized at the cDNA and putative amino acid levels, allowing for phylogenetic analysis of these proteins in teleost fish, as well as the development of gene-specific primers used in RT-PCR and quantitative PCR (QPCR) analyses. Two Atlantic cod Irf10 splice variants were identified and their presence confirmed by sequencing of the Irf10 genomic region. RT-PCR showed that Irf7, Irf8 and both Irf10 transcripts were expressed in all 15 cod tissues tested, while Irf4a and Irf4b were absent in some tissues. QPCR analysis of spleen expression expanded upon this, and upon previous work. All IRF transcripts in the study were responsive to stimulation by the viral mimic poly(I:C), and all except Irf4a were responsive to exposure to formalin-killed Aeromonas salmonicida (ASAL). These IRF genes, thus, are likely important in the cod immune response to both viral and bacterial infections. Increased temperature (10 °C to 16 °C) was also observed to modulate the antibacterial responses of all IRF transcripts, and the antiviral responses of Irf4b and Irf10-v2. This research supports earlier studies which reported that elevated temperature modulates the expression of many immune genes in Atlantic cod. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Evolutionary redesign of the Atlantic cod (Gadus morhua L.) Toll-like receptor repertoire by gene losses and expansions

    OpenAIRE

    Solbakken, Monica H.; T?rresen, Ole K.; Nederbragt, Alexander J.; Seppola, Marit; Gregers, Tone F.; Jakobsen, Kjetill S.; Jentoft, Sissel

    2016-01-01

    Published version. Source at http://doi.org/10.1038/srep25211. License CC BY 4.0. Genome sequencing of the teleost Atlantic cod demonstrated loss of the Major Histocompatibility Complex (MHC) class II, an extreme gene expansion of MHC class I and gene expansions and losses in the innate pattern recognition receptor (PRR) family of Toll-like receptors (TLR). In a comparative genomic setting, using an improved version of the genome, we characterize PRRs in Atlantic cod with emphasis on TL...

  7. The hypoxia avoidance behaviour of juvenile Atlantic cod (Gadus morhua L.) depends on the provision and pressure level of an O2 refuge

    DEFF Research Database (Denmark)

    Herbert, Neill A.; Skjaeraasen, Jon E.; Nilsen, Trygve

    2011-01-01

    The frequency of low O(2) (hypoxia) has increased in coastal marine areas but how fish avoid deleterious water masses is not yet clear. To assess whether the presence and oxygen pressure (PO(2)) level of an O(2) refuge affects the hypoxia avoidance behaviour of fish, individual Atlantic cod (Gadus...... morhua L.) were exposed to a range of O(2) choices in a 2-way choice chamber at 11.4 degrees C over two different experiments. Cod in the first experiment were allowed access to a fixed O(2) refuge (fully air-saturated seawater) whilst oxygen pressure (PO(2)) on the other side was reduced in steps...... to a critically low level, i.e. 4.3 kPa-a point where cod can no longer regulate O(2) consumption. Under these conditions, cod did not avoid any level of hypoxia and fish swimming speed also remained unchanged. In contrast, strong avoidance reactions were exhibited in a second experiment when fish were again...

  8. Effect of replacement of fish oil with camelina (Camelina sativa) oil on growth, lipid class and fatty acid composition of farmed juvenile Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Hixson, Stefanie M; Parrish, Christopher C; Anderson, Derek M

    2013-12-01

    Camelina (Camelina sativa) oil was tested as a replacement for fish oil in diets for farmed Atlantic cod (Gadus morhua). Camelina differs from other plant oilseeds previously used in aquaculture with high lipid (40 %), α-linolenic acid (40 %), antioxidants and low proportions of saturated fats. Dietary treatments were fed to cod (19 g fish⁻¹ initial weight) for 9 weeks and included a fish oil control (FO), 40 % (CO40) and 80 % (CO80) replacement of fish oil with camelina oil. There was no effect of replacing fish oil with camelina oil included at levels up to 80 % on the growth performance. Cod fed CO80 stored more lipid in the liver (p CO40 > CO80; p Camelina oil can reduce the amount of fish oil needed to meet lipid requirements, although replacing 80 % of fish oil reduced LC PUFAs in both tissues. A comparison of BF₃ and H₂SO₄ as catalysts to transmethylate cod liver and muscle lipids revealed small but significant differences in some fatty acid proportions.

  9. Electrical stunning of farmed Atlantic cod Gadus morhua L.: a comparison of an industrial and experimental method

    NARCIS (Netherlands)

    Digre, H.; Erikson, U.; Misimi, E.; Lambooij, E.; Vis, van de J.W.

    2010-01-01

    An industrial and experimental electrical method for stunning farmed Atlantic cod in air and seawater (SW), respectively, were compared. The impacts of sedation with AQUI-S™ and exercise to exhaustion before electrical stunning were also assessed to monitor the possible depletion of rested muscle

  10. The responses of Atlantic cod (Gadus morhua L.) to ultrasound-emitting predators: stress, behavioural changes or debilitation?

    DEFF Research Database (Denmark)

    Schack, H.B.; Malte, H.; Madsen, Peter Teglberg

    2008-01-01

    A previous study has reported that Atlantic cod can be conditioned to detect ultrasonic sound pulses of high intensity. This capability has been proposed as a mean for detection and avoidance of echolocating toothed whales that emit intense ultrasonic clicks. In this study, we use acoustic playba...

  11. Harvest Pressure on Coastal Atlantic Cod (Gadus morhua from Recreational Fishing Relative to Commercial Fishing Assessed from Tag-Recovery Data.

    Directory of Open Access Journals (Sweden)

    Alf Ring Kleiven

    Full Text Available Marine recreational fishing is a popular outdoor activity. However, knowledge about the magnitude of recreational catches relative to commercial catches in coastal fisheries is generally sparse. Coastal Atlantic cod (Gadus morhua is a target species for recreational fishers in the North Atlantic. In Norway, recreational fishers are allowed to use a variety of traps and nets as well as long-line and rod and line when fishing for cod. From 2005 to 2013, 9729 cod (mean size: 40 cm, range: 15-93 cm were tagged and released in coastal Skagerrak, southeast Norway. Both high-reward (NOK 500 and low-reward tags (NOK 50 were used in this study. Because some harvested fish (even those posting high-reward tags may go unreported by fishers, reporting rates were estimated from mark-recovery models that incorporate detection parameters in their structure, in addition to survival and mortality estimates. During 2005 to 2013, a total of 1707 tagged cod were recovered and reported by fishers. We estimate the overall annual survival to be 33% (SE 1.5. Recreational rod and line fishing were responsible for 33.7% (SE 2.4 of total mortality, followed by commercial fisheries (15.1% SE 0.8 and recreational fixed gear (6.8% SE 0.4. Natural mortality was 44.4% (SE 2.5 of total mortality. Our findings suggest that recreational fishing-rod and line fishing in particular-is responsible for a substantial part of fishing mortality exerted on coastal cod in southern Norway.

  12. Harvest Pressure on Coastal Atlantic Cod (Gadus morhua) from Recreational Fishing Relative to Commercial Fishing Assessed from Tag-Recovery Data.

    Science.gov (United States)

    Kleiven, Alf Ring; Fernandez-Chacon, Albert; Nordahl, Jan-Harald; Moland, Even; Espeland, Sigurd Heiberg; Knutsen, Halvor; Olsen, Esben Moland

    2016-01-01

    Marine recreational fishing is a popular outdoor activity. However, knowledge about the magnitude of recreational catches relative to commercial catches in coastal fisheries is generally sparse. Coastal Atlantic cod (Gadus morhua) is a target species for recreational fishers in the North Atlantic. In Norway, recreational fishers are allowed to use a variety of traps and nets as well as long-line and rod and line when fishing for cod. From 2005 to 2013, 9729 cod (mean size: 40 cm, range: 15-93 cm) were tagged and released in coastal Skagerrak, southeast Norway. Both high-reward (NOK 500) and low-reward tags (NOK 50) were used in this study. Because some harvested fish (even those posting high-reward tags) may go unreported by fishers, reporting rates were estimated from mark-recovery models that incorporate detection parameters in their structure, in addition to survival and mortality estimates. During 2005 to 2013, a total of 1707 tagged cod were recovered and reported by fishers. We estimate the overall annual survival to be 33% (SE 1.5). Recreational rod and line fishing were responsible for 33.7% (SE 2.4) of total mortality, followed by commercial fisheries (15.1% SE 0.8) and recreational fixed gear (6.8% SE 0.4). Natural mortality was 44.4% (SE 2.5) of total mortality. Our findings suggest that recreational fishing-rod and line fishing in particular-is responsible for a substantial part of fishing mortality exerted on coastal cod in southern Norway.

  13. A nuclear DNA basis for shelf- and bank scale population structure in northwest Atlantic cod ( Gadus morhua ) : Labrador to Georges Bank

    DEFF Research Database (Denmark)

    Ruzzante, D.E.; Taggart, C.T.; Cook, D.

    1998-01-01

    Variation at five microsatellite DNA loci scored in approximate to 1300 individuals provided evidence of genetic structure among 14 cod (Gadus morhua) populations spanning the range of the species in the northwest (NW) Atlantic. Using DA and Ds, measures of genetic distance, as well as F-ST and R...... structure at spawning-bank scales consistent with variation in oceanographic features and in the spatiotemporal distribution of spawning, each of which may represent barriers to gene flow among geographically contiguous populations inhabiting a highly advective environment. The differences described...... by the associated oceanographic features and processes that conceivably form the template for the evolution of the structure. We suggest that bathymetric and hydrodynamic structure represents a rational starting point for developing hypotheses to examine the processes that lead to the genetic structuring of marine...

  14. Changes in regional brain monoaminergic activity and temporary down-regulation in stress response from dietary supplementation with l-tryptophan in Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Basic, D.; Schjolden, J.; Krogdahl, A.

    2013-01-01

    or four times the Trp levels in commercial feed, last in juvenile Atlantic cod (Gadus morhua) when the fish are reintroduced to a diet with standard amino acid composition. We also wanted to determine whether Trp supplementation induced changes in brain monoaminergic neurochemistry in those forebrain...... structures innervated by DA- and 5-HTergic neurons, by measuring regional activity of DA and 5-HT in the lateral pallial regions (Dl) of the telencephalon and nucleus lateralis tuberis (NLT) of the hypothalamus. Dietary Trp resulted in a dose-dependent suppression in plasma cortisol among fish exposed...... to confinement stress on the first day following experimental diet; however, such an effect was not observed at 2 or 6 d after Trp treatment. Feeding the fish with moderate Trp doses also evoked a general increase in DA and 5-HT-ergic activity, suggesting that these neural circuits within the NLT and Dl may...

  15. Cortisol levels and expression of selected stress- and apoptosis-related genes in the embryos of Atlantic cod, Gadus morhua following short-term exposure to air

    DEFF Research Database (Denmark)

    Marlowe, Christopher; Caipang, A.; Fagutao, Ferdinand F.

    2015-01-01

    Embryos (morula stage) of Atlantic cod, Gadus morhua L., were collected and subjected to air exposure for 2 min. followed by recovery at ambient conditions in the rearing container. Total immunoreactive cortisol and transcription of selected stress- and apoptosis-related genes of the embryos were...... determined before the application of the stressor and at 0.5, 1 and 24 h post-exposure. There was no significant difference in the total cortisol levels of the fertilized eggs before and after handling stress. There was high expression level of hsp70 and sod before application of the stressor...... and significantly increased at 0.5 h postexposure. The expression levels of cat and gpx were weak to moderate and were not affected by the stressor. The apoptotic genes, mcl1 and NR-13 were highly expressed and significantly increased after exposure to air. Bcl-X1 and Bcl-X2 were moderately expressed in the control...

  16. Ocean Acidification Portends Acute Habitat Compression for Atlantic Cod (Gadus morhua) in a Physiologically-informed Metabolic Rate Model

    Science.gov (United States)

    Del Raye, G.; Weng, K.

    2011-12-01

    Ocean acidification affects organisms on a biochemical scale, yet its societal impacts manifest from changes that propagate through entire populations. Successful forecasting of the effects of ocean acidification therefore depends on at least two steps: (1) deducing systemic physiology based on subcellular stresses and (2) scaling individual physiology up to ecosystem processes. Predictions that are based on known biological processes (process-based models) may fare better than purely statistical models in both these steps because the latter are less robust to novel environmental conditions. Here we present a process-based model that uses temperature, pO2, and pCO2 to predict maximal aerobic scope in Atlantic cod. Using this model, we show that (i) experimentally-derived physiological parameters are sufficient to capture the response of cod aerobic scope to temperature and oxygen, and (ii) subcellular pH effects can be used to predict the systemic physiological response of cod to an acidified ocean. We predict that acute pH stress (on a scale of hours) could limit the mobility of Atlantic cod during diel vertical migration across a pCO2 gradient, promoting habitat compression. Finally, we use a global sensitivity analysis to identify opportunities for the improvement of model uncertainty as well as some physiological adaptations that could mitigate climate stresses on cod in the future.

  17. An investigation of appetite-related peptide transcript expression in Atlantic cod (Gadus morhua) brain following a Camelina sativa meal-supplemented feeding trial.

    Science.gov (United States)

    Tuziak, Sarah M; Rise, Matthew L; Volkoff, Hélène

    2014-10-25

    Camelina sativa is a hardy oilseed crop with seeds that contain high levels of ω3 polyunsaturated fatty acids and protein, which are critical components of fish feed. Camelina might thus be used as a cheaper and more sustainable supplement to fish-based products in aquaculture. Atlantic cod, Gadus morhua, is a species of interest in the aquaculture industry due to a decrease in wild populations and subsequent collapse of some cod fisheries. As cod are carnivorous fish, it is necessary to determine how this species physiologically tolerates plant-based diets. In this study, juvenile Atlantic cod were subjected to 13 weeks of either 15 or 30% camelina meal (CM)-supplemented diets or a control fish meal feed. Growth and food intake were evaluated and the mRNA expression of appetite-related hormones [pro-melanin-concentrating hormone (pmch), hypocretin (synonym: orexin, hcrt), neuropeptide Y (npy) and cocaine- and amphetamine-regulated transcript (cart)] was assessed using quantitative real-time PCR in brain regions related to food intake regulation (telencephalon/preoptic area, optic tectum/thalamus and hypothalamus). CM inclusion diets caused decreases in both growth and food intake in Atlantic cod. Optic tectum pmch transcript expression was significantly higher in fish fed the 30% CM diet compared to fish fed the 15% CM diet. In the hypothalamus, compared to fish fed the control diet, hcrt expression was significantly higher in fish fed the 30% CM diet, while npy transcript expression was significantly higher in fish fed the 15% CM diet. cart mRNA expression was not affected by diet in any brain region. Further studies are needed to determine which factors (e.g. anti-nutritional factors, palatability and nutritional deficits) contribute to reduced feed intake and growth, as well as the maximum CM inclusion level that does not negatively influence feed intake, growth rate and the transcript expression of appetite-related factors in Atlantic cod. Copyright © 2014

  18. Variation in embryonic mortality and maternal transcript expression among Atlantic cod (Gadus morhua) broodstock: a functional genomics study.

    Science.gov (United States)

    Rise, Matthew L; Nash, Gordon W; Hall, Jennifer R; Booman, Marije; Hori, Tiago S; Trippel, Edward A; Gamperl, A Kurt

    2014-12-01

    Early life stage mortality is an important issue for Atlantic cod aquaculture, yet the impact of the cod maternal (egg) transcriptome on egg quality and mortality during embryonic development is poorly understood. In the present work, we studied embryonic mortality and maternal transcript expression using eggs from 15 females. Total mortality at 7days post-fertilization (7 dpf, segmentation stage) was used as an indice of egg quality. A 20,000 probe (20K) microarray experiment compared the 7hours post-fertilization (7 hpf, ~2-cell stage) egg transcriptome of the two lowest quality females (>90% mortality at 7 dpf) to that of the highest quality female (~16% mortality at 7 dpf). Forty-three microarray probes were consistently differentially expressed in both low versus high quality egg comparisons (25 higher expressed in low quality eggs, and 18 higher expressed in high quality eggs). The microarray experiment also identified many immune-relevant genes [e.g. interferon (IFN) pathway genes ifngr1 and ifrd1)] that were highly expressed in eggs of all 3 females regardless of quality. Twelve of the 43 candidate egg quality-associated genes, and ifngr1, ifrd1 and irf7, were included in a qPCR study with 7 hpf eggs from all 15 females. Then, the genes that were confirmed by qPCR to be greater than 2-fold differentially expressed between 7 hpf eggs from the lowest and highest quality females (dcbld1, ddc, and acy3 more highly expressed in the 2 lowest quality females; kpna7 and hacd1 more highly expressed in the highest quality female), and the 3 IFN pathway genes, were included in a second qPCR study with unfertilized eggs. While some maternal transcripts included in these qPCR studies were associated with extremes in egg quality, there was little correlation between egg quality and gene expression when all females were considered. Both dcbld1 and ddc showed greater than 100-fold differences in transcript expression between females and were potentially influenced by

  19. Preferred temperature of juvenile Atlantic cod Gadus morhua with different haemoglobin genotypes at normoxia and moderate hypoxia

    DEFF Research Database (Denmark)

    Petersen, Maria Faldborg; Steffensen, John Fleng

    2003-01-01

    .2+/-1.5 degrees C while HbI-1 cod preferred 15.4+/-1.1 degrees C, and this preference was significant. The effect of hypoxia (35% oxygen saturation) on the preferred temperature was also measured. Previous studies showed that the preferred temperature of fish decreases during hypoxia, and this was the case for Hb......I-1 cod, which preferred 9.8+/-1.8 degrees C during hypoxia, whereas HbI-2 cod did not show this effect. The results indicate that environmental temperature changes will lead to a distributional change in the different haemoglobin types of Atlantic cod, global warming providing an advantage for HbI-1...... in northern regions, and the HbI(1) allele dominant in warmer areas. To determine if temperature is a selective parameter in the distribution of the haemoglobin types, the preferred temperature of the homozygous genotypes HbI-1 and HbI-2 was measured. We found that HbI-2 cod preferred a temperature of 8...

  20. The effect of temperature and body size on metabolic scope of activity in juvenile Atlantic cod Gadus morhua L.

    Science.gov (United States)

    Tirsgaard, Bjørn; Behrens, Jane W; Steffensen, John F

    2015-01-01

    Changes in ambient temperature affect the physiology and metabolism and thus the distribution of fish. In this study we used intermittent flow respirometry to determine the effect of temperature (2, 5, 10, 15 and 20°C) and wet body mass (BM) (~30-460g) on standard metabolic rate (SMR, mgO2h(-1)), maximum metabolic rate (MMR, mgO2h(-1)) and metabolic scope (MS, mgO2h(-1)) of juvenile Atlantic cod. SMR increased with BM irrespectively of temperature, resulting in an average scaling exponent of 0.87 (0.82-0.92). Q10 values were 1.8-2.1 at temperatures between 5 and 15°C but higher (2.6-4.3) between 2 and 5°C and lower (1.6-1.4) between 15 and 20°C in 200 and 450g cod. MMR increased with temperature in the smallest cod (50g) but in the larger cod MMR plateaued between 10, 15 and 20°C. This resulted in a negative correlation between the optimal temperature for MS (Topt) and BM, Topt being respectively 14.5, 11.8 and 10.9°C in a 50, 200 and 450g cod. Irrespective of BM cold water temperatures resulted in a reduction (30-35%) of MS whereas the reduction of MS at warm temperatures was only evident for larger fish (200 and 450g), caused by plateauing of MMR at 10°C and above. Warm temperatures thus seem favourable for smaller (50g) juvenile cod, but not for larger conspecifics (200 and 450g). Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Differentially expressed proteins in the skin mucus of Atlantic cod (Gadus morhua) upon natural infection with Vibrio anguillarum

    Science.gov (United States)

    2013-01-01

    Background Vibriosis caused by V. anguillarum is a commonly encountered disease in Atlantic cod farms and several studies indicate that the initiation of infection occurs after the attachment of the pathogen to the mucosal surfaces (gut, skin and gills) of fish. Therefore it is necessary to investigate the role of different mucosal components in fish upon V. anguillarum infection. The present study has two parts; in the first part we analyzed the differential expression of skin mucus proteins from Atlantic cod naturally infected with V. anguillarum using two dimensional gel electrophoresis coupled with mass spectrometry. In the second part, a separate bath challenge experiment with V. anguillarum was conducted to assess the mRNA levels of the genes in skin tissue, corresponding to the selected proteins identified in the first part. Results Comparative proteome analysis of skin mucus of cod upon natural infection with V. anguillarum revealed key immune relevant proteins like calpain small subunit 1, glutathione-S-transferase omega 1, proteasome 26S subunit, 14-kDa apolipoprotein, beta 2-tubulin, cold inducible RNA binding protein, malate dehydrogenase 2 (mitochondrial) and type II keratin that exhibited significant differential expression. Additionally a number of protein spots which showed large variability amongst individual fish were also identified. Some of the proteins identified were mapped to the immunologically relevant JNK (c-Jun N-terminal kinases) signalling pathway that is connected to cellular events associated with pathogenesis. A bath challenge experiment with V. anguillarum showed differential expression of beta 2-tubulin, calpain small subunit 1, cold inducible RNA binding protein, flotillin1, and glutathione S-transferase omega 1 transcripts in the skin tissue of cod during early stages of infection. Conclusions Differentially expressed proteins identified in the cod skin mucus point towards their possible involvement in V. anguillarum pathogenesis

  2. Differentially expressed proteins in the skin mucus of Atlantic cod (Gadus morhua) upon natural infection with Vibrio anguillarum.

    Science.gov (United States)

    Rajan, Binoy; Lokesh, Jep; Kiron, Viswanath; Brinchmann, Monica F

    2013-05-14

    Vibriosis caused by V. anguillarum is a commonly encountered disease in Atlantic cod farms and several studies indicate that the initiation of infection occurs after the attachment of the pathogen to the mucosal surfaces (gut, skin and gills) of fish. Therefore it is necessary to investigate the role of different mucosal components in fish upon V. anguillarum infection. The present study has two parts; in the first part we analyzed the differential expression of skin mucus proteins from Atlantic cod naturally infected with V. anguillarum using two dimensional gel electrophoresis coupled with mass spectrometry. In the second part, a separate bath challenge experiment with V. anguillarum was conducted to assess the mRNA levels of the genes in skin tissue, corresponding to the selected proteins identified in the first part. Comparative proteome analysis of skin mucus of cod upon natural infection with V. anguillarum revealed key immune relevant proteins like calpain small subunit 1, glutathione-S-transferase omega 1, proteasome 26S subunit, 14-kDa apolipoprotein, beta 2-tubulin, cold inducible RNA binding protein, malate dehydrogenase 2 (mitochondrial) and type II keratin that exhibited significant differential expression. Additionally a number of protein spots which showed large variability amongst individual fish were also identified. Some of the proteins identified were mapped to the immunologically relevant JNK (c-Jun N-terminal kinases) signalling pathway that is connected to cellular events associated with pathogenesis. A bath challenge experiment with V. anguillarum showed differential expression of beta 2-tubulin, calpain small subunit 1, cold inducible RNA binding protein, flotillin1, and glutathione S-transferase omega 1 transcripts in the skin tissue of cod during early stages of infection. Differentially expressed proteins identified in the cod skin mucus point towards their possible involvement in V. anguillarum pathogenesis. The role of some of these

  3. Validation of reference genes for quantitative RT-qPCR studies of gene expression in Atlantic cod (Gadus morhua l. during temperature stress

    Directory of Open Access Journals (Sweden)

    Karlsen Hans E

    2011-04-01

    Full Text Available Abstract Background One important physiological response to environmental stress in animals is change in gene expression. To obtain reliable data from gene expression studies using RT-qPCR it is important to evaluate a set of possible reference genes as normalizers for expression. The expression of these candidate genes should be analyzed in the relevant tissues during normal and stressed situations. To find suitable reference genes it was crucial that the genes were stably expressed also during a situation of physiological stress. For poikilotermic animals like cod, changes in temperature are normal, but if the changes are faster than physiological compensation, the animals respond with typical stress responses. It has previously been shown that Atlantic cod show stress responses when elevation of water temperature is faster than 1 degree/day, for this reason we chose hyperthermia as stress agent for this experiment. Findings We here describe the expression of eight candidate reference genes from Atlantic cod (Gadus morhua l. and their stability during thermal stress (temperature elevation of one degree C/day for 5 days. The genes investigated were: Eukaryotic elongation factor 1 alpha, ef1a; 18s ribosomal RNA; 18s, Ubiquitin conjugate protein; ubiq, cytoskeletal beta-actin; actb, major histcompatibility complex I; MHC-I light chain, beta-2 -microglobulin; b2m, cytoskeletal alpha-tubulin; tba1c, acidic ribosomal phosphoprotein; rplp1, glucose-6-phosphate dehydrogenase; g6pd. Their expression were analyzed in 6 tissues (liver, head kidney, intestine, spleen, heart and gills from cods exposed to elevated temperature and compared to a control group. Although there were variations between tissues with respect to reference gene stability, four transcripts were more consistent than the others: ubiq, ef1a, 18s and rplp1. We therefore used these to analyze the expression of stress related genes (heat shock proteins induced during hyperthermia. We found

  4. Growth pattern and growth dependent mortality of larval and pelagic juvenile North Sea cod Gadus morhua

    DEFF Research Database (Denmark)

    Nielsen, Rune; Munk, Peter

    2004-01-01

    We investigated growth patterns and evidence of growth dependent survival for a population of Atlantic cod Gadus morhua using analysis of their otolith microstructure. Central concentrations of a population of cod larvae and juveniles in the north-eastern North Sea were sampled twice (in April...

  5. Seasonal trends in adenylate nucleotide content in eggs of recruit and repeat spawning Atlantic cod (Gadus morhua L.) and implications for egg quality and buoyancy

    Science.gov (United States)

    Jung, Kyung-Mi; Svardal, Asbjørn M.; Eide, Torunn; Thorsen, Anders; Kjesbu, Olav Sigurd

    2012-10-01

    Seasonal and ontogenetic variation in egg buoyancy (egg specific gravity; ρ) (n = 63) and nucleotide content (n = 46) were examined for wild-caught Atlantic (Barents Sea) cod (Gadus morhua) held in captivity over two successive spawning seasons, i.e. each female (n = 5) was studied both as recruit and repeat spawner. All eggs were naturally spawned and fertilized, and incubated under optimal condition in flow-through aquaria. Egg diameter and egg dry weight declined steadily during the spawning period, while stage-specific ρ was approximately constant between egg batches (typically around 15 in total). Within each egg batch, i.e. during egg incubation, ρ significantly decreased from the time of gastrulation to before hatching, accompanied by increased contents of ATP and ADP. Altogether, we found that adenylate energy charge (EC) (EC = ([ATP] + 0.5 [ADP]) / ([ATP] + [ADP] + [AMP]) positively affected egg buoyancy (P = 0.013) in concert with egg developmental stage (P cod eggs in the field would show comparably similar trends in ρ and levels of nucleotides.

  6. Seasonal variation in biomarkers in blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua)-Implications for environmental monitoring in the Barents Sea

    Energy Technology Data Exchange (ETDEWEB)

    Nahrgang, J., E-mail: jasmine.m.nahrgang@uit.no [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Brooks, S.J. [Norwegian Institute for Water Research (NIVA), NO-0349 Oslo (Norway); Evenset, A. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Camus, L. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University Centre In Svalbard (UNIS), NO-9171 Longyearbyen (Norway); Jonsson, M.; Smith, T.J. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Lukina, J. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University of Tromso, Faculty of Biosciences, Fisheries and Economics, Department of Arctic and Marine Biosciences, NO-9037 Tromso (Norway); Frantzen, M. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); Giarratano, E. [Centro Nacional Patagonico (CENPAT-CONICET), AR-9120 Puerto Madryn (Argentina); Renaud, P.E. [Akvaplan-niva, FRAM Centre, NO-9296 Tromso (Norway); University Centre In Svalbard (UNIS), NO-9171 Longyearbyen (Norway)

    2013-02-15

    In the Barents Sea, the limited data on biological relevant indicators and their responses to various anthropogenic stressors have hindered the development of a consistent scientific basis for selecting indicator species and developing practical procedures for environmental monitoring. Accordingly, the main aim of the present study was to develop a common set of baseline values for contaminants and biomarkers in three species, and to identify their strengths and limitations in monitoring of the Barents Sea. Blue mussel (Mytilus edulis), Icelandic scallop (Chlamys islandica) and Atlantic cod (Gadus morhua) were sampled from a north Norwegian fjord in March, June, September and December 2010. Digestive glands from the bivalve species and liver from Atlantic cod were analysed for biomarkers of oxidative stress (catalase [CAT], glutathione peroxidase [GPX], glutathione-S-transferase activities [GST], lipid peroxidation as thiobarbituric reactive substances [TBARS] and total oxyradical scavenging capacity [TOSC]), biotransformation (ethoxyresorufine-O-deethylase activity [EROD]) and general stress (lysosomal membrane stability [LMS]). Concentrations of polycyclic aromatic hydrocarbons (PAHs) and metals in the bivalves and PAH metabolites in fish bile were quantified. Finally, energy reserves (total lipids, proteins and carbohydrates) and electron transport system (ETS) activity in the digestive gland of the bivalves and liver of Atlantic cod provided background information for reproductive cycle and general physiological status of the organisms. Blue mussel and Icelandic scallop showed very similar trends in biological cycle, biomarker expression and seasonality. Biomarker baselines in Atlantic cod showed weaker seasonal variability. However, important biological events may have been undetected due to the large time intervals between sampling occasions. Physiological biomarkers such as energy reserves and ETS activity were recommended as complementary parameters to the

  7. Evolutionary history and adaptive significance of the polymorphic Pan I in migratory and stationary populations of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Andersen, Øivind; Johnsen, Hanne; De Rosa, Maria Cristina; Præbel, Kim; Stjelja, Suzana; Kirubakaran, Tina Graceline; Pirolli, Davide; Jentoft, Sissel; Fevolden, Svein-Erik

    2015-08-01

    The synaptophysin (SYP) family comprises integral membrane proteins involved in vesicle-trafficking events, but the physiological function of several members has been enigmatic for decades. The presynaptic SYP protein controls neurotransmitter release, while SYP-like 2 (SYPL2) contributes to maintain normal Ca(2+)-signaling in the skeletal muscles. The polymorphic pantophysin (Pan I) of Atlantic cod shows strong genetic divergence between stationary and migratory populations, which seem to be adapted to local environmental conditions. We have investigated the functional involvement of Pan I in the different ecotypes by analyzing the 1) phylogeny, 2) spatio-temporal gene expression, 3) structure-function relationship of the Pan I(A) and I(B) protein variants, and 4) linkage to rhodopsin (rho) recently proposed to be associated with different light sensitivities in Icelandic populations of Atlantic cod. We searched for SYP family genes in phylogenetic key species and identified a single syp-related gene in three invertebrate chordates, while four members, Syp, Sypl1, Sypl2 and synaptoporin (Synpr), were found in tetrapods, Comoran coelacanth and spotted gar. Teleost fish were shown to possess duplicated syp, sypl2 and synpr genes of which the sypl2b paralog is identical to Pan I. The ubiquitously expressed cod Pan I codes for a tetra-spanning membrane protein possessing five amino acid substitutions in the first intravesicular loop, but only minor structural differences were shown between the allelic variants. Despite sizable genomic distance (>2.5 Mb) between Pan I and rho, highly significant linkage disequilibrium was found by genotyping shallow and deep water juvenile settlers predominated by the Pan I(A)-rho(A) and Pan I(B)-rho(B) haplotypes, respectively. However, the predicted rhodopsin protein showed no amino acid changes, while multiple polymorphic sites in the upstream region might affect the gene expression and pigment levels in stationary and migratory cod

  8. Effects of amino acid supplementations on metabolic and physiological parameters in Atlantic cod (Gadus morhua) under stress.

    Science.gov (United States)

    Herrera, Marcelino; Herves, María Antonia; Giráldez, Inmaculada; Skar, Kristin; Mogren, Hanne; Mortensen, Atle; Puvanendran, Velmurugu

    2017-04-01

    The effects of tryptophan (Trp) and phenylalanine (Phe) diet supplementation on the stress and metabolism of the Atlantic cod have been studied. Fish were fed diet supplemented with Trp or Phe or control diet for 1 week. At the end of the feeding trial, fish were subjected to air exposure or heat shock. Following samples of blood, liver and muscle were taken from the fish and were analyzed for stress and metabolic indicators. After an air exposure, plasma cortisol levels in fish fed with Trp and Phe diets were lower compared to the fish fed the control diet. Diets containing both amino acids increased significantly the liver transaminase activities in juvenile cod. During thermal stress, high Trp contents had significant effects on fructose biphosphatase activity though Phe did not. Overall, activities of glucose 6-phosphate dehydrogenase, pyruvate kinase, and phosphofructokinase increased significantly for both amino acid diets. For the thermal stress, fish had the highest values of those activities for the 3Trp diet. Trp content in the diet had significant effects on the transaminase activity in muscle during air stress compared to fish fed control and Phe diets. Muscle alanine transaminase activity for thermal stress in fish fed any diet was not significantly different from the control. Both Trp and Phe supplementations reduced the stress markers in the cod; hence, they could be used as additives for the stress attenuation. However, they also raised the activity of key enzymes in glycolysis and gluconeogenesis, mainly the Trp diets.

  9. Chronic CO2 exposure markedly increases the incidence of cataracts in juvenile Atlantic cod Gadus morhua L

    DEFF Research Database (Denmark)

    Moran, Damian; Tubbs, Lincoln; Støttrup, Josianne G.

    2012-01-01

    A study was undertaken to test the affect of chronic exposure to elevated dissolved carbon dioxide on juvenile Atlantic cod. The CO2 treatment concentrations were designated as low (1–2mgL−1, 1000μatm), medium (8mgL−1, 3500μatm) and high (18mgL−1, 8500μatm), and the fish were reared at 10°C and 20......=757 individuals) using field methods. The most notable difference between CO2 treatments was the prevalence and intensity of lenticular cataracts, which were primarily diffuse rather than nucleated. Nearly 75% of all fish from the high CO2 treatment were found to have some degree of cataractous lesion......, compared with 10–13% for the other treatments. The severity of the cataract was most pronounced at the highest CO2 concentration, with many fish presenting complete bilateral cataracts. These data indicate that chronic exposure to high CO2 concentrations can cause cataracts in juvenile Atlantic cod. To our...

  10. Quantitative proteomics analysis reveals perturbation of lipid metabolic pathways in the liver of Atlantic cod (Gadus morhua) treated with PCB 153.

    Science.gov (United States)

    Yadetie, Fekadu; Oveland, Eystein; Døskeland, Anne; Berven, Frode; Goksøyr, Anders; Karlsen, Odd André

    2017-04-01

    PCB 153 is one of the most abundant PCB congeners detected in biological samples. It is a persistent compound that is still present in the environment despite the ban on production and use of PCBs in the late 1970s. It has strong tendencies to bioaccumulate and biomagnify in biota, and studies have suggested that it is an endocrine and metabolic disruptor. In order to study mechanisms of toxicity, we exposed Atlantic cod (Gadus morhua) to various doses of PCB 153 (0, 0.5, 2 and 8mg/kg body weight) for two weeks and examined the effects on expression of liver proteins using label-free quantitative proteomics. Label-free liquid chromatography-mass spectrometry analysis of the liver proteome resulted in the quantification of 1272 proteins, of which 78 proteins were differentially regulated in the PCB 153-treated dose groups compared to the control group. Functional enrichment analysis showed that pathways significantly affected are related to lipid metabolism, cytoskeletal remodeling, cell cycle and cell adhesion. Importantly, the main effects appear to be on lipid metabolism, with up-regulation of enzymes in the de novo fatty acid synthesis pathway, consistent with previous transcriptomics results. Increased plasma triglyceride levels were also observed in the PCB 153 treated fish, in agreement with the induction of the lipogenic genes and proteins. The results suggest that PCB 153 perturbs lipid metabolism in the Atlantic cod liver. Elevated levels of lipogenic enzymes and plasma triglycerides further suggest increased synthesis of fatty acids and triglycerides. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Comparison of the response of Atlantic cod ( Gadus morhua) in the high-latitude regions of the North Atlantic during the warm periods of the 1920s-1960s and the 1990s-2000s

    Science.gov (United States)

    Drinkwater, Ken

    2009-10-01

    Concern about future anthropogenic warming has lead to demands for information on what might happen to fish and fisheries under various climate-change scenarios. One suggestion has been to use past events as a proxy for what will happen in the future. In this paper a comparison between the responses of Atlantic cod ( Gadus morhua) to two major warm periods in the North Atlantic during the 20th century is carried out to determine how reliable the past might be as a predictor of the future. The first warm period began during the 1920s, remained relatively warm through the 1960s, and was limited primarily to the northern regions (>60°N). The second warm period, which again covered the northern regions but also extended farther south (30°N), began in the 1990s and has continued into the present century. During the earlier warm period, the most northern of the cod stocks (West Greenland, Icelandic, and Northeast Arctic cod in the Barents Sea) increased in abundance, individual growth was high, recruitment was strong, and their distribution spread northward. Available plankton data suggest that these cod responses were driven by bottom-up processes. Fishing pressure increased during this period of high cod abundance and the northern cod stocks began to decline, as early as the 1950s in the Barents Sea but during the 1960s elsewhere. Individual growth declined as temperatures cooled and the cod distributions retracted southward. During the warming in the 1990s, the spawning stock biomass of cod in the Barents Sea again increased, recruitment rose, and the stock spread northward, but the individual growth did not improve significantly. Cod off West Greenland also have shown signs of improving recruitment and increasing biomass, albeit they are still very low in comparison to the earlier warming period. The abundance of Icelandic cod, on the other hand, has remained low through the recent warm period and spawning stock biomass and total biomass are at levels near the

  12. The effect of temperature and body size on metabolic scope of activity in juvenile Atlantic cod Gadus morhua L

    DEFF Research Database (Denmark)

    Tirsgaard, Bjørn; Behrens, Jane; Steffensen, John Fleng

    2015-01-01

    Changes in ambient temperature affect the physiology and metabolism and thus the distribution of fish. In this study we used intermittent flow respirometry to determine the effect of temperature (2, 5, 10, 15 and 20 °C) and wet body mass (BM) (~30–460 g) on standard metabolic rate (SMR, mg O2 h−1......), maximum metabolic rate (MMR, mg O2 h−1) and metabolic scope (MS, mg O2 h−1) of juvenile Atlantic cod. SMR increased with BM irrespectively of temperature, resulting in an average scaling exponent of 0.87 (0.82–0.92). Q10 values were 1.8–2.1 at temperatures between 5 and 15 °C but higher (2.6–4.3) between...

  13. Effects of Hypoxic Exposure during Feeding on SDA and Postprandial Cardiovascular Physiology in the Atlantic Cod, Gadus morhua

    Science.gov (United States)

    Behrens, Jane W.; Axelsson, Michael; Neuenfeldt, Stefan; Seth, Henrik

    2012-01-01

    Some Atlantic cod in the Bornholm Basin undertake vertical foraging migrations into severely hypoxic bottom water. Hypoxic conditions can reduce the postprandial increase in gastrointestinal blood flow (GBF). This could subsequently postpone or reduce the postprandial increase in oxygen consumption (MO2), i.e. the SDA, leading to a disturbed digestion. Additionally, a restricted oxygen uptake could result in an oxygen debt that needs to be compensated for upon return to normoxic waters and this may also affect the ability to process the food. Long-term cardio-respiratory measurements were made on fed G. morhua in order to understand how the cardio-respiratory system of feeding fish respond to a period of hypoxia and a subsequent return to normoxia. These were exposed to 35% water oxygen saturation for 90 minutes, equivalent to the time and oxygen level cod voluntarily endure when searching for food in the Bornholm Basin. We found that i) gastric and intestinal blood flows, cardiac output and MO2 increased after feeding, ii) gastric and intestinal blood flows were spared in hypoxia, and iii) there were no indications of an oxygen debt at the end of the hypoxic period. The magnitude and time course of the measured variables are similar to values obtained from fish not exposed to the hypoxic period. In conclusion, when cod in the field search for and ingest prey under moderate hypoxic conditions they appear to stay within safe limits of oxygen availability as we saw no indications of an oxygen debt, or negative influence on digestive capacity, when simulating field observations. PMID:23049987

  14. Is chemically dispersed oil more toxic to Atlantic cod (Gadus morhua) larvae than mechanically dispersed oil? A transcriptional evaluation

    Science.gov (United States)

    2012-01-01

    Background The use of dispersants can be an effective way to deal with acute oil spills to limit environmental damage, however very little is known about whether chemically dispersed oil have the same toxic effect on marine organisms as mechanically dispersed oil. We exposed Atlantic cod larvae to chemically and mechanically dispersed oil for four days during the first-feeding stage of development, and collected larvae at 14 days post hatch for transcriptional analysis. A genome-wide microarray was used to screen for effects and to assess whether molecular responses to chemically and mechanically dispersed oil were similar, given the same exposure to oil (droplet distribution and concentration) with and without the addition of a chemical dispersant (Dasic NS). Results Mechanically dispersed oil induced expression changes in almost three times as many transcripts compared to chemically dispersed oil (fold change >+/−1.5). Functional analyses suggest that chemically dispersed oil affects partly different pathways than mechanically dispersed oil. By comparing the alteration in gene transcription in cod larvae exposed to the highest concentrations of either chemically or mechanically dispersed oil directly, the chemically dispersed oil affected transcription of genes involved nucleosome regulation, i.e. genes encoding proteins participating in DNA replication and chromatin formation and regulation of cell proliferation, whereas the mechanically dispersed oil most strongly affected genes encoding proteins involved in proteasome-mediated protein degradation. Cyp1a was the transcript that was most strongly affected in both exposure groups, with a 60-fold induction in the two high-exposure groups according to the RT-qPCR data, but no significant difference in transcriptional levels was observed between the two treatments. Conclusions In summary, dispersants do not appear to add to the magnitude of transcriptional responses of oil compounds but rather appear to lower or

  15. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae - can we identify the underlying factors?

    Science.gov (United States)

    Karlsen, Ørjan; van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks.

  16. Is chemically dispersed oil more toxic to Atlantic cod (Gadus morhua larvae than mechanically dispersed oil? A transcriptional evaluation

    Directory of Open Access Journals (Sweden)

    Olsvik Pål A

    2012-12-01

    Full Text Available Abstract Background The use of dispersants can be an effective way to deal with acute oil spills to limit environmental damage, however very little is known about whether chemically dispersed oil have the same toxic effect on marine organisms as mechanically dispersed oil. We exposed Atlantic cod larvae to chemically and mechanically dispersed oil for four days during the first-feeding stage of development, and collected larvae at 14 days post hatch for transcriptional analysis. A genome-wide microarray was used to screen for effects and to assess whether molecular responses to chemically and mechanically dispersed oil were similar, given the same exposure to oil (droplet distribution and concentration with and without the addition of a chemical dispersant (Dasic NS. Results Mechanically dispersed oil induced expression changes in almost three times as many transcripts compared to chemically dispersed oil (fold change >+/−1.5. Functional analyses suggest that chemically dispersed oil affects partly different pathways than mechanically dispersed oil. By comparing the alteration in gene transcription in cod larvae exposed to the highest concentrations of either chemically or mechanically dispersed oil directly, the chemically dispersed oil affected transcription of genes involved nucleosome regulation, i.e. genes encoding proteins participating in DNA replication and chromatin formation and regulation of cell proliferation, whereas the mechanically dispersed oil most strongly affected genes encoding proteins involved in proteasome-mediated protein degradation. Cyp1a was the transcript that was most strongly affected in both exposure groups, with a 60-fold induction in the two high-exposure groups according to the RT-qPCR data, but no significant difference in transcriptional levels was observed between the two treatments. Conclusions In summary, dispersants do not appear to add to the magnitude of transcriptional responses of oil compounds but

  17. Effects of hypoxic exposure during feeding on SDA and postprandial cardiovascular physiology in the Atlantic cod, Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Jane W Behrens

    Full Text Available Some Atlantic cod in the Bornholm Basin undertake vertical foraging migrations into severely hypoxic bottom water. Hypoxic conditions can reduce the postprandial increase in gastrointestinal blood flow (GBF. This could subsequently postpone or reduce the postprandial increase in oxygen consumption (MO(2, i.e. the SDA, leading to a disturbed digestion. Additionally, a restricted oxygen uptake could result in an oxygen debt that needs to be compensated for upon return to normoxic waters and this may also affect the ability to process the food. Long-term cardio-respiratory measurements were made on fed G. morhua in order to understand how the cardio-respiratory system of feeding fish respond to a period of hypoxia and a subsequent return to normoxia. These were exposed to 35% water oxygen saturation for 90 minutes, equivalent to the time and oxygen level cod voluntarily endure when searching for food in the Bornholm Basin. We found that i gastric and intestinal blood flows, cardiac output and MO(2 increased after feeding, ii gastric and intestinal blood flows were spared in hypoxia, and iii there were no indications of an oxygen debt at the end of the hypoxic period. The magnitude and time course of the measured variables are similar to values obtained from fish not exposed to the hypoxic period. In conclusion, when cod in the field search for and ingest prey under moderate hypoxic conditions they appear to stay within safe limits of oxygen availability as we saw no indications of an oxygen debt, or negative influence on digestive capacity, when simulating field observations.

  18. Changes in regional brain monoaminergic activity and temporary down-regulation in stress response from dietary supplementation with l-tryptophan in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Basic, Dean; Schjolden, Joachim; Krogdahl, Ashild; von Krogh, Kristine; Hillestad, Marie; Winberg, Svante; Mayer, Ian; Skjerve, Eystein; Höglund, Erik

    2013-06-28

    The brain monoamines serotonin (5-hydroxytryptamine; 5-HT) and dopamine (DA) both play an integrative role in behavioural and neuroendocrine responses to challenges, and comparative models suggest common mechanisms for dietary modulation of transmission by these signal substances in vertebrates. Previous studies in teleosts demonstrate that 7 d of dietary administration with L-tryptophan (Trp), the direct precursor of 5-HT, suppresses the endocrine stress response. The present study investigated how long the suppressive effects of a Trp-enriched feed regimen, at doses corresponding to two, three or four times the Trp levels in commercial feed, last in juvenile Atlantic cod (Gadus morhua) when the fish are reintroduced to a diet with standard amino acid composition. We also wanted to determine whether Trp supplementation induced changes in brain monoaminergic neurochemistry in those forebrain structures innervated by DA and 5-HTergic neurons, by measuring regional activity of DA and 5-HT in the lateral pallial regions (Dl) of the telencephalon and nucleus lateralis tuberis (NLT) of the hypothalamus. Dietary Trp resulted in a dose-dependent suppression in plasma cortisol among fish exposed to confinement stress on the first day following experimental diet; however, such an effect was not observed at 2 or 6 d after Trp treatment. Feeding the fish with moderate Trp doses also evoked a general increase in DA and 5-HT-ergic activity, suggesting that these neural circuits within the NLT and Dl may be indirectly involved in regulating the acute stress response.

  19. Understanding the release efficiency of Atlantic cod (Gadus morhua) from trawls with a square mesh panel: effects of panel area, panel position, and stimulation of escape response

    DEFF Research Database (Denmark)

    Herrmann, Bent; Wienbeck, Harald; Karlsen, Junita Diana

    2015-01-01

    Based on size selectivity data for more than 25 000 cod (Gadus morhua) collected during experimental trawl fishing with six different codends, all of which included a square mesh panel,we investigated the effect on cod-release efficiency based on the size of the square mesh panel area, position...... of the square mesh panel, and stimulation of the escape response. Based on the results, we were able to explain why the BACOMAcodend, applied in the Baltic Sea cod directed trawl fishery, releases juvenile cod efficiently, whereas other designs, including a squaremesh panel with similar mesh size, are less...... the catch-accumulation zone. Our findings demonstrated that this release was as efficient as for a panel mounted in the catch-accumulation zone of the codend. Devices that stimulate behaviour may improve the release efficiency of cod through square mesh panels in other fisheries where this is a problem...

  20. Plasticity in activity and latency to explore differs between juvenile Atlantic cod Gadus morhua across a temperature gradient.

    Science.gov (United States)

    Reynisson, H; Ólafsdóttir, G Á

    2018-01-01

    In the current study activity and latency to explore, as well as the correlation of these traits, were examined in individually marked juvenile Gadus morhua at 7, 10 and 13° C. It was concluded that individual rank order of both traits was maintained across temperature but that the level of change differed between individuals. © 2017 The Fisheries Society of the British Isles.

  1. Geolocation of North Sea cod (Gadus morhua) using Hidden Markov Models and behavioural switching

    DEFF Research Database (Denmark)

    Pedersen, Martin Wæver; Righton, David; Thygesen, Uffe Høgsbro

    2008-01-01

    When geolocating fish based on archival tag data, a realistic assessment of uncertainty is essential. Here, we describe an application of a novel Fokker–Planck-based method to geolocate Atlantic cod (Gadus morhua) in the North Sea area. In this study, the geolocation relies mainly on matching tidal...

  2. A review of the contributions of fisheries and climate variability to contrasting dynamics in two Arcto-boreal Atlantic cod (Gadus morhua) stocks: Persistent high productivity in the Barents Sea and collapse on the Newfoundland and Labrador Shelf

    Science.gov (United States)

    Lilly, George R.; Nakken, Odd; Brattey, John

    2013-07-01

    Stocks of Atlantic cod (Gadus morhua) across the North Atlantic and adjacent seas have been fished intensively for years, and many are now severely depleted. In order to promote recovery and sustainable harvesting, it is essential to understand factors that have contributed to the declines and to variability in rates of recovery. Considerable insight may be gleaned by comparing and contrasting the histories of the Northeast Arctic (NEA) cod in the Barents Sea - Svalbard area of the northeast Atlantic and the “northern cod” on the Newfoundland and Labrador (NL) shelf in the northwest Atlantic. These two stocks, which were among the 3 largest cod stocks during the middle of the 20th century, are Arcto-boreal, and have many species of prey and predators in common. The biomass of NEA cod has varied considerably over time, and in 2009 was a little above 60% of its maximum observed level, which occurred in the late 1940s and early 1950s. In contrast, the biomass of NL cod decreased steadily from the early 1960s to the late 1970s, increased somewhat during the 1980s, and crashed during the early 1990s to an extremely low level, at which it remained for a decade before showing recent indications of improvement. Although both stocks were influenced by similar changes in harvesting strategies and environmental circumstances, both biotic and abiotic, there are two events which stand out as being particularly influential. First, crises developed in the management of both stocks in the late 1980s. For NEA cod, the crisis was environmental, caused by the collapse of capelin (Mallotus villosus), the main food for adult cod, whereas for NL cod the crisis was caused by a sudden large reduction in scientific perception of stock size. The difference in response to these crises strongly influenced subsequent stock dynamics. Catches of NEA cod were reduced considerably, preventing severe overharvesting of the cod that at that time experienced low productivity, whereas catches of NL

  3. Diel vertical interactions between Atlantic cod Gadus morhua and sprat Sprattus sprattus in a stratified water column

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner; Lundgren, Bo; Neuenfeldt, Stefan

    2017-01-01

    , respectively. Cod resided close to the bottom outside these temporal predation windows. Sprat schools were located at the same depth as cod in the daylight hours, whereas at night dispersed sprat were situated higher in the water column. These vertical dynamics could be explained by fitness optimization using...... bioenergetics and trade-offs between temperature, oxygen saturation of the water and predation risk. This study forms a first step towards providing a mechanistic background for the predatory impact of cod at the basin scale and beyond...

  4. Regional changes in vertebra morphology during ontogeny reflect the life history of Atlantic cod (Gadus morhua L.)

    Science.gov (United States)

    Fjelldal, Per G; Totland, Geir K; Hansen, Tom; Kryvi, Harald; Wang, Xiyuan; Søndergaard, Jens L; Grotmol, Sindre

    2013-01-01

    This study examined vertebra formation, morphology, regional characters, and bending properties of the vertebral column of Atlantic cod throughout its life cycle (0–6 years). The first structure to form was the foremost neural arch, 21 days post hatching (dph), and the first vertebra centrum to form – as a chordacentrum – was the 3rd centrum at 28 dph. Thereafter, the notochord centra developed in a regular sequence towards the head and caudal fin. All vertebrae were formed within 50 dph. The vertebral column consisted of 52 (± 2) vertebrae (V) and could be divided into four distinct regions: (i) the cervical region (neck) (V1 and V2), characterized by short vertebra centra, prominent neural spines and absence of articulations with ribs; (ii) the abdominal region (trunk) (V3–V19), characterized by vertebrae with wing-shaped transverse processes (parapophyses) that all articulate with a rib; (iii) the caudal region (tail) (V20–V40), where the vertebra centra have haemal arches with prominent haemal spines; (iv) the ural region (V41 to the last vertebra), characterized by broad neural and haemal spines, providing sites of origin for muscles inserting on the fin rays – lepidotrichs – of the tail fin. The number of vertebrae in the cervical, abdominal and caudal regions was found to be constant, whereas in the ural region, numbers varied from 12 to 15. Geometric modelling based on combination of vertebra lengths, diameters and intervertebral distances showed an even flexibility throughout the column, except in the ural region, where flexibility increased. Throughout ontogeny, the vertebra centra of the different regions followed distinct patterns of growth; the relative length of the vertebrae increased in the cervical and abdominal regions, and decreased in the caudal and ural regions with increasing age. This may reflect changes in swimming mode with age, and/or that the production of large volumes of gametes during sexual maturation requires a

  5. Molecular identification and transmission studies of X-cell parasites from Atlantic cod Gadus morhua (Gadiformes: Gadidae and the northern black flounder Pseudopleuronectes obscurus (Pleuronectiformes: Pleuronectidae

    Directory of Open Access Journals (Sweden)

    Watanabe K

    2011-02-01

    Full Text Available Abstract Background Epidermal pseudotumours from Hippoglossoides dubius and Acanthogobius flavimanus in Japan and gill lesions in Limanda limanda from the UK have been shown to be caused by phylogenetically related protozoan parasites, known collectively as X-cells. However, the phylogenetic position of the X-cell group is not well supported within any of the existing protozoan phyla and they are currently thought to be members of the Alveolata. Ultrastructural features of X-cells in fish pseudotumours are somewhat limited and no typical environmental stages, such as spores or flagellated cells, have been observed. The life cycles for these parasites have not been demonstrated and it remains unknown how transmission to a new host occurs. In the present study, pseudobranchial pseudotumours from Atlantic cod, Gadus morhua, in Iceland and epidermal pseudotumours from the northern black flounder, Pseudopleuronectes obscurus, in Japan were used in experimental transmission studies to establish whether direct transmission of the parasite is achievable. In addition, X-cells from Atlantic cod were sequenced to confirm whether they are phylogenetically related to other X-cells and epidermal pseudotumours from the northern black flounder were analysed to establish whether the same parasite is responsible for infecting different flatfish species in Japan. Results Phylogenetic analyses of small subunit ribosomal DNA (SSU rDNA sequence data from Atlantic cod X-cells show that they are a related parasite that occupies a basal position to the clade containing other X-cell parasites. The X-cell parasite causing epidermal pseudotumours in P. obscurus is the same parasite that causes pseudotumours in H. dubius. Direct, fish to fish, transmission of the X-cell parasites used in this study, via oral feeding or injection, was not achieved. Non-amoeboid X-cells are contained within discrete sac-like structures that are loosely attached to epidermal pseudotumours in

  6. Effects of dietary fatty acids on the production and quality of eggs and larvae of Atlantic cod (Gadus morhua L.)

    DEFF Research Database (Denmark)

    Røjbek, Maria; Støttrup, Josianne; Jacobsen, Charlotte

    2014-01-01

    –173% higher in eggs than in diets. Cod fed the diet with the lowest EPA/ARA ratio had the greatest egg production. Eggs from fish on a diet with high ARA level had significantly higher fertilization and hatching success than those fed low levels of ARA. This diet produced on average 71 viable eggs g 1 female...

  7. The third serine proteinase with chymotrypsin specificity isolated from Atlantic cod (Gadus morhua) is a type-II elastase

    DEFF Research Database (Denmark)

    Asgeirsson, B; Leth-Larsen, Rikke; Thórólfsson, M

    1998-01-01

    efficiency of elastase C. The effects of several inhibitors on cod elastase C were identical to effects on chymotrypsins variants A and B, but dissimilar when compared with porcine pancreatic elastase. On the basis of the specificity and amino acid sequence, we conclude that the enzyme under study is most...

  8. Biomarker candidate discovery in Atlantic cod (Gadus morhua) continuously exposed to North Sea produced water from egg to fry

    DEFF Research Database (Denmark)

    Bohne-Kjersem, Anneli; Bache, Nicolai; Meier, Sonnich

    2010-01-01

    spectrometry, using a newly developed cod EST database and the NCBI database. Many of the protein changes occurred at low levels (0.01% and 0.1% PW) of exposure, indicating putative biological responses at lower levels than previously detected. Using discriminant analysis, we identified a set of protein...

  9. Early life of key fish species, capelin Mallotus villosus and Atlantic cod Gadus morhua, in West Greenland

    DEFF Research Database (Denmark)

    Malanski, Evandro

    feeding on prey sizes of about 5% of their own size (Paper I) and consequently the prey preference spectra covered calanoid nauplii, cladocerans and calanoid copepodites with increasing larval size. In the Godthåbsfjord system and Fyllas Bank area, 4 hydrographic zones were defined; in each zone distinct...... of preference – and of importance as biomass consumed – were calanoid nauplii and cyclopoid copepodites. The findings indicate that capelin and cod larvae were not competing for food as their prey size spectra do not overlap. While cod is preying on larger organisms as they develop, the increase in maximally...... is linked to the break-up of ice cover and the subsequent irradiance increase in the water column, climatic changes in Arctic regions could lead to a mismatch between larval emergence and optimal conditions for their feeding and growth. Thus it would be feasible to investigate the capelin stock genetic...

  10. Cod Gadus morhua and climate change: processes, productivity and prediction

    DEFF Research Database (Denmark)

    Brander, Keith

    2010-01-01

    the causes. Investigation of cod Gadus morhua populations across the whole North Atlantic Ocean has shown large-scale patterns of change in productivity due to lower individual growth and condition, caused by large-scale climate forcing. If a population is being heavily exploited then a drop in productivity......Environmental factors act on individual fishes directly and indirectly. The direct effects on rates and behaviour can be studied experimentally and in the field, particularly with the advent of ever smarter tags for tracking fishes and their environment. Indirect effects due to changes in food......, predators, parasites and diseases are much more difficult to estimate and predict. Climate can affect all life-history stages through direct and indirect processes and although the consequences in terms of growth, survival and reproductive output can be monitored, it is often difficult to determine...

  11. Effect of sub-lethal exposure to ultraviolet radiation on the escape performance of Atlantic cod larvae (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Yuichi Fukunishi

    Full Text Available The amount of ultraviolet (UV radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments: two-spotted goby (Gobiusculus flavescens; a suction predator and lion's mane jellyfish (Cyanea capillata; a "passive" ambush predator. Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100, escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively were significantly lower than those of control larvae (75%, 69±4.7 mm respectively. There was a significant difference in survival as well (UV: 35%,63%. No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%,74% in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations.

  12. The impact of a moderate chronic temperature increase on spleen immune-relevant gene transcription depends on whether Atlantic cod (Gadus morhua) are stimulated with bacterial versus viral antigens.

    Science.gov (United States)

    Hori, Tiago S; Gamperl, A Kurt; Nash, Gord; Booman, Marije; Barat, Ashoktaru; Rise, Matthew L

    2013-10-01

    Exposure to elevated temperature is an inherent feature of Atlantic cod (Gadus morhua) sea-cage culture in some regions (e.g., Newfoundland) and may also become an increasingly prevalent challenge for wild fish populations because of accelerated climate change. Therefore, understanding how elevated temperatures impacts the immune response of this commercially important species may help to reduce the potential negative impacts of such challenges. Previously, we investigated the impacts of moderately elevated temperature on the antiviral responses of Atlantic cod (Hori et al. 2012) and reported that elevated temperature modulated the spleen transcriptome response to polyriboinosinic polyribocytidylic acid (pIC, a viral mimic). Herein, we report a complementary microarray study that investigated the impact of the same elevated temperature regime on the Atlantic cod spleen transcriptome response to intraperitoneal (IP) injection of formalin-killed Aeromonas salmonicida (ASAL). Fish were held at two different temperatures (10 °C and 16 °C) prior to immune stimulation and sampled 6 and 24 h post-injection (HPI). In this experiment, we identified 711 and 666 nonredundant ASAL-responsive genes at 6HPI and 24HPI, respectively. These included several known antibacterial genes, including hepcidin, cathelicidin, ferritin heavy subunit, and interleukin 8. However, we only identified 15 differentially expressed genes at 6HPI and 2 at 24HPI (FDR 1%) when comparing ASAL-injected fish held at 10 °C versus 16 °C. In contrast, the same comparisons with pIC-injected fish yielded 290 and 339 differentially expressed genes (FDR 1%) at 6HPI and 24HPI, respectively. These results suggest that moderately elevated temperature has a lesser effect on the Atlantic cod spleen transcriptome response to ASAL (i.e., the antibacterial response) than to pIC (i.e., antiviral response). Thus, the impacts of high temperatures on the cod's immune response may be pathogen dependent.

  13. Effects of hypoxic exposure during feeding on SDA and postprandial cardiovascular physiology in the Atlantic cod, Gadus morhua

    DEFF Research Database (Denmark)

    Behrens, Jane; Axelsson, Michael; Neuenfeldt, Stefan

    2012-01-01

    (MO2), i.e. the SDA, leading to a disturbed digestion. Additionally, a restricted oxygen uptake could result in an oxygen debt that needs to be compensated for upon return to normoxic waters and this may also affect the ability to process the food. Long-term cardio-respiratory measurements were made...... on fed G. morhua in order to understand how the cardio-respiratory system of feeding fish respond to a period of hypoxia and a subsequent return to normoxia. These were exposed to 35% water oxygen saturation for 90 minutes, equivalent to the time and oxygen level cod voluntarily endure when searching...... of an oxygen debt, or negative influence on digestive capacity, when simulating field observations...

  14. THE EFFECT OF HYPOXIA ON THE MAXIMUM MATABOLIC RATE AND SPECIFIC DYNAMIC ACTION IN ATLANTIC COD Gadus morhua

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2010-01-01

    of hypoxia compared. Maximum metabolic rate compared to standard metabolic rate is termed the Scope for Activity. The results showed that hypoxia at 6.3 kPa does influence the SDA. The effect on the SDA curve on cod fed 5 % of the wet body mass was that the peak metabolic rate was significantly depressed (44...... and fish kept at high densities. Feeding is followed by an increase in the metabolic rate. termed the specific dynamic action (SDA). SDA integrates all the energetic expenditures involved in feeding. It is generally agreed that the increased metabolic rate is caused by biochemical transformation of food...... the fi sh. The fish were fed single rations of fillets of herring, equivalent to 5 % wet body mass. Hypoxia was controlled by an oxygen regulator injecting compressed nitrogen in the water via a solenoid valve. In addition the maximum metabolic rate of starved fish was measured in normoxia and 4 levels...

  15. Atlantic cod (Gadus morhua) larvae can biosynthesis phospholipid de novo from 2-oleoyl-glycerol and glycerol precursors.

    Science.gov (United States)

    Li, Keshuai; Olsen, Rolf Erik; Østensen, Mari-Ann; Altin, Dag; Kjørsvik, Elin; Olsen, Yngvar

    2016-02-01

    The dietary requirement of phospholipid (PL) of fish larvae has been suggested to originate in an inefficient ability for de novo biosynthesis of PL based on dietary triacylglycerol (TAG). The main objective of the present study was to investigate whether cod larvae could synthesis PL from sn-2-monoacylglycerol (2-MAG) and glycerol precursors. A tube feeding method was used to deliver equal molar aliquots of 2-oleoyl-[1,2,3-(3)H]glycerol and [U-(14)C] glycerol together with bovine serum albumin (BSA) bound 16:0 (palmitic acid) and 22:6n-3 (docosahexaenoic acid, DHA), with or without choline chloride to the foregut of anesthetized cod larvae and thereafter monitoring the metabolism of these components in the larvae through 4 h following injection. Our results showed that both 2-MAG and glycerol precursors contributed to the de novo synthesis of phosphatidylcholine (PC) and the 2-MAG pathway predominated over the G-3-P (glycerol-3-phosphate) pathway in the synthesis of TAG and PC. The molecular ratio of PC/TAG obtained from the 2-MAG and the G-3-P pathways was 0.44-0.74 and 1.02-2.06 within the first hour of tube feeding, suggesting they might have comparable biosynthesis ability of PC and TAG under the conditions of the present study. Furthermore, supplementation of choline chloride significantly increased PC/TAG ratio (p < 0.05) for both pathways. However, further studies are needed to quantify the enzyme activity involved in the CDP-choline (cytidine diphosphate choline) pathway, and the function of choline either in simulating PC synthesis or TAG catabolism or both needs further investigation.

  16. Historical changes in genotypic frequencies at the Pantophysin locus in Atlantic cod (Gadus morhua) in Icelandic waters: evidence of fisheries-induced selection?

    OpenAIRE

    Jakobsdóttir, Klara B; Pardoe, Heidi; Magnússon, Árni; Björnsson, Höskuldur; Pampoulie, Christophe; Ruzzante, Daniel E.; Marteinsdóttir, Guðrún

    2011-01-01

    The intense fishing mortality imposed on Atlantic cod in Icelandic waters during recent decades has resulted in marked changes in stock abundance, as well as in age and size composition. Using a molecular marker known to be under selection (Pan I) along with a suite of six neutral microsatellite loci, we analysed an archived data set and revealed evidence of distinct temporal changes in the frequencies of genotypes at the Pan I locus among spawning Icelandic cod, collected between 1948 and 20...

  17. Polymorphism, selection and tandem duplication of transferrin genes in Atlantic cod (Gadus morhua - Conserved synteny between fish monolobal and tetrapod bilobal transferrin loci

    Directory of Open Access Journals (Sweden)

    Tooming-Klunderud Ave

    2011-05-01

    Full Text Available Abstract Background The two homologous iron-binding lobes of transferrins are thought to have evolved by gene duplication of an ancestral monolobal form, but any conserved synteny between bilobal and monolobal transferrin loci remains unexplored. The important role played by transferrin in the resistance to invading pathogens makes this polymorphic gene a highly valuable candidate for studying adaptive divergence among local populations. Results The Atlantic cod genome was shown to harbour two tandem duplicated serum transferrin genes (Tf1, Tf2, a melanotransferrin gene (MTf, and a monolobal transferrin gene (Omp. Whereas Tf1 and Tf2 were differentially expressed in liver and brain, the Omp transcript was restricted to the otoliths. Fish, chicken and mammals showed highly conserved syntenic regions in which monolobal and bilobal transferrins reside, but contrasting with tetrapods, the fish transferrin genes are positioned on three different linkage groups. Sequence alignment of cod Tf1 cDNAs from Northeast (NE and Northwest (NW Atlantic populations revealed 22 single nucleotide polymorphisms (SNP causing the replacement of 16 amino acids, including eight surface residues revealed by the modelled 3D-structures, that might influence the binding of pathogens for removal of iron. SNP analysis of a total of 375 individuals from 14 trans-Atlantic populations showed that the Tf1-NE variant was almost fixed in the Baltic cod and predominated in the other NE Atlantic populations, whereas the NW Atlantic populations were more heterozygous and showed high frequencies of the Tf-NW SNP alleles. Conclusions The highly conserved synteny between fish and tetrapod transferrin loci infers that the fusion of tandem duplicated Omp-like genes gave rise to the modern transferrins. The multiple nonsynonymous substitutions in cod Tf1 with putative structural effects, together with highly divergent allele frequencies among different cod populations, strongly suggest

  18. Polymorphism, selection and tandem duplication of transferrin genes in Atlantic cod (Gadus morhua)--conserved synteny between fish monolobal and tetrapod bilobal transferrin loci.

    Science.gov (United States)

    Andersen, Øivind; De Rosa, Maria Cristina; Pirolli, Davide; Tooming-Klunderud, Ave; Petersen, Petra E; André, Carl

    2011-05-25

    The two homologous iron-binding lobes of transferrins are thought to have evolved by gene duplication of an ancestral monolobal form, but any conserved synteny between bilobal and monolobal transferrin loci remains unexplored. The important role played by transferrin in the resistance to invading pathogens makes this polymorphic gene a highly valuable candidate for studying adaptive divergence among local populations. The Atlantic cod genome was shown to harbour two tandem duplicated serum transferrin genes (Tf1, Tf2), a melanotransferrin gene (MTf), and a monolobal transferrin gene (Omp). Whereas Tf1 and Tf2 were differentially expressed in liver and brain, the Omp transcript was restricted to the otoliths. Fish, chicken and mammals showed highly conserved syntenic regions in which monolobal and bilobal transferrins reside, but contrasting with tetrapods, the fish transferrin genes are positioned on three different linkage groups. Sequence alignment of cod Tf1 cDNAs from Northeast (NE) and Northwest (NW) Atlantic populations revealed 22 single nucleotide polymorphisms (SNP) causing the replacement of 16 amino acids, including eight surface residues revealed by the modelled 3D-structures, that might influence the binding of pathogens for removal of iron. SNP analysis of a total of 375 individuals from 14 trans-Atlantic populations showed that the Tf1-NE variant was almost fixed in the Baltic cod and predominated in the other NE Atlantic populations, whereas the NW Atlantic populations were more heterozygous and showed high frequencies of the Tf-NW SNP alleles. The highly conserved synteny between fish and tetrapod transferrin loci infers that the fusion of tandem duplicated Omp-like genes gave rise to the modern transferrins. The multiple nonsynonymous substitutions in cod Tf1 with putative structural effects, together with highly divergent allele frequencies among different cod populations, strongly suggest evidence for positive selection and local adaptation in

  19. Polymorphism, selection and tandem duplication of transferrin genes in Atlantic cod (Gadus morhua) - Conserved synteny between fish monolobal and tetrapod bilobal transferrin loci

    Science.gov (United States)

    2011-01-01

    Background The two homologous iron-binding lobes of transferrins are thought to have evolved by gene duplication of an ancestral monolobal form, but any conserved synteny between bilobal and monolobal transferrin loci remains unexplored. The important role played by transferrin in the resistance to invading pathogens makes this polymorphic gene a highly valuable candidate for studying adaptive divergence among local populations. Results The Atlantic cod genome was shown to harbour two tandem duplicated serum transferrin genes (Tf1, Tf2), a melanotransferrin gene (MTf), and a monolobal transferrin gene (Omp). Whereas Tf1 and Tf2 were differentially expressed in liver and brain, the Omp transcript was restricted to the otoliths. Fish, chicken and mammals showed highly conserved syntenic regions in which monolobal and bilobal transferrins reside, but contrasting with tetrapods, the fish transferrin genes are positioned on three different linkage groups. Sequence alignment of cod Tf1 cDNAs from Northeast (NE) and Northwest (NW) Atlantic populations revealed 22 single nucleotide polymorphisms (SNP) causing the replacement of 16 amino acids, including eight surface residues revealed by the modelled 3D-structures, that might influence the binding of pathogens for removal of iron. SNP analysis of a total of 375 individuals from 14 trans-Atlantic populations showed that the Tf1-NE variant was almost fixed in the Baltic cod and predominated in the other NE Atlantic populations, whereas the NW Atlantic populations were more heterozygous and showed high frequencies of the Tf-NW SNP alleles. Conclusions The highly conserved synteny between fish and tetrapod transferrin loci infers that the fusion of tandem duplicated Omp-like genes gave rise to the modern transferrins. The multiple nonsynonymous substitutions in cod Tf1 with putative structural effects, together with highly divergent allele frequencies among different cod populations, strongly suggest evidence for positive

  20. Where does the cod come from? Panels of gene‐associated markers provide vastly improved origin assignment in Atlantic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Hansen, Jakob Hemmer; Taylor, Martin

    2012-01-01

    Methods for determining the geographical origin of individual fish are in high demand for fighting illegal, unreported, and unregulated (IUU) fishing and for independent control of catch certificates and “eco‐labels”. Hitherto, genetic origin assignment of marine fish has been hampered by the gen...... relevant for controlling illegal fishing, ecolabels, and fisheries management. Our results demonstrate how application of gene‐associated markers will probably revolutionize origin assignment in cod by providing faster, cheaper, and more reliable tools for origin assignment...

  1. Characterization and expression analyses of anti-apoptotic Bcl-2-like genes NR-13, Mcl-1, Bcl-X1, and Bcl-X2 in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Feng, Charles Y; Rise, Matthew L

    2010-01-01

    NR-13, Mcl-1, and BCL-X(L), are conserved anti-apoptotic proteins that belong to the anti-apoptotic Bcl-2 sub-family, which inhibits cell death by preventing mitochondrial membrane permeabilization (MMP). Given the anti-apoptotic functions of these proteins in vertebrates (e.g. human, mouse, and zebrafish) and the involvement of apoptotic regulation in immune responses, we studied the sequences of these genes and their transcript expression in Atlantic cod (Gadus morhua) during innate immune responses to viral and bacterial stimuli. Based on previously generated Atlantic cod expressed sequence tags (ESTs), we identified partial cDNA sequences of putative orthologues of Atlantic cod NR-13, Mcl-1, and Bcl-X, and obtained the full-length cDNA, genomic, and promoter region sequences for these genes. The analyses of Atlantic cod cDNA sequences, and comparisons of the cod deduced amino acid sequences to putative orthologues in other species, revealed the presence of highly conserved Bcl-2 homology (BH) and transmembrane (TM) domains in the Atlantic cod sequences. Analysis of gene structure revealed conserved intron/exon boundaries within the coding regions of human and Atlantic cod putative orthologues. We found that an intron/exon boundary immediately following the codon for the 8th residue (tryptophan) of the BH2 domain exists in all anti-apoptotic Bcl-2 sub-family genes regardless of vast evolutionary distance. We also identified a non-coding exon in the Atlantic cod NR-13-like gene, which appears to be absent in its putative mammalian orthologues. Quantitative reverse transcription-polymerase chain reaction (QPCR) was used to study constitutive gene expression in six tissues (blood, brain, gill, head kidney, pyloric caecum, and spleen) of non-stressed juvenile cod; NR-13 and Bcl-X2 were most highly expressed in gill, whereas Mcl-1 and Bcl-X1 were most highly expressed in blood. In cod challenged with intraperitoneal (IP) injections of the viral mimic polyriboinosinic

  2. In vitro pH-Stat protein hydrolysis of feed ingredients for Atlantic cod, Gadus morhua. 2. In vitro protein digestibility of common and alternative feed ingredients

    NARCIS (Netherlands)

    Tibbetts, S.; Verreth, J.A.J.; Lall, S.P.

    2011-01-01

    Using enzyme fractions isolated from the pyloric caeca of farmed Atlantic cod, the in vitro degree of protein hydrolysis (DH) of numerous conventional and novel feed ingredients were measured by a closed-system pH-Stat assay. Regression equations describing the relationship between in vivo apparent

  3. Discovery of miRNAs and Their Corresponding miRNA Genes in Atlantic Cod (Gadus morhua): Use of Stable miRNAs as Reference Genes Reveals Subgroups of miRNAs That Are Highly Expressed in Particular Organs.

    Science.gov (United States)

    Andreassen, Rune; Rangnes, Fredrik; Sivertsen, Maria; Chiang, Michelle; Tran, Michelle; Worren, Merete Molton

    2016-01-01

    Atlantic cod (Gadus morhua) is among the economically most important species in the northern Atlantic Ocean and a model species for studying development of the immune system in vertebrates. MicroRNAs (miRNAs) are an abundant class of small RNA molecules that regulate fundamental biological processes at the post-transcriptional level. Detailed knowledge about a species miRNA repertoire is necessary to study how the miRNA transcriptome modulate gene expression. We have therefore discovered and characterized mature miRNAs and their corresponding miRNA genes in Atlantic cod. We have also performed a validation study to identify suitable reference genes for RT-qPCR analysis of miRNA expression in Atlantic cod. Finally, we utilized the newly characterized miRNA repertoire and the dedicated RT-qPCR method to reveal miRNAs that are highly expressed in certain organs. The discovery analysis revealed 490 mature miRNAs (401 unique sequences) along with precursor sequences and genomic location of the miRNA genes. Twenty six of these were novel miRNA genes. Validation studies ranked gmo-miR-17-1-5p or the two-gene combination gmo-miR25-3p and gmo-miR210-5p as most suitable qPCR reference genes. Analysis by RT-qPCR revealed 45 miRNAs with significantly higher expression in tissues from one or a few organs. Comparisons to other vertebrates indicate that some of these miRNAs may regulate processes like growth, lipid metabolism, immune response to microbial infections and scar damage repair. Three teleost-specific and three novel Atlantic cod miRNAs were among the differentially expressed miRNAs. The number of known mature miRNAs was considerably increased by our identification of miRNAs and miRNA genes in Atlantic cod. This will benefit further functional studies of miRNA expression using deep sequencing methods. The validation study showed that stable miRNAs are suitable reference genes for RT-qPCR analysis of miRNA expression. Applying RT-qPCR we have identified several mi

  4. Discovery of miRNAs and Their Corresponding miRNA Genes in Atlantic Cod (Gadus morhua: Use of Stable miRNAs as Reference Genes Reveals Subgroups of miRNAs That Are Highly Expressed in Particular Organs.

    Directory of Open Access Journals (Sweden)

    Rune Andreassen

    Full Text Available Atlantic cod (Gadus morhua is among the economically most important species in the northern Atlantic Ocean and a model species for studying development of the immune system in vertebrates. MicroRNAs (miRNAs are an abundant class of small RNA molecules that regulate fundamental biological processes at the post-transcriptional level. Detailed knowledge about a species miRNA repertoire is necessary to study how the miRNA transcriptome modulate gene expression. We have therefore discovered and characterized mature miRNAs and their corresponding miRNA genes in Atlantic cod. We have also performed a validation study to identify suitable reference genes for RT-qPCR analysis of miRNA expression in Atlantic cod. Finally, we utilized the newly characterized miRNA repertoire and the dedicated RT-qPCR method to reveal miRNAs that are highly expressed in certain organs.The discovery analysis revealed 490 mature miRNAs (401 unique sequences along with precursor sequences and genomic location of the miRNA genes. Twenty six of these were novel miRNA genes. Validation studies ranked gmo-miR-17-1-5p or the two-gene combination gmo-miR25-3p and gmo-miR210-5p as most suitable qPCR reference genes. Analysis by RT-qPCR revealed 45 miRNAs with significantly higher expression in tissues from one or a few organs. Comparisons to other vertebrates indicate that some of these miRNAs may regulate processes like growth, lipid metabolism, immune response to microbial infections and scar damage repair. Three teleost-specific and three novel Atlantic cod miRNAs were among the differentially expressed miRNAs.The number of known mature miRNAs was considerably increased by our identification of miRNAs and miRNA genes in Atlantic cod. This will benefit further functional studies of miRNA expression using deep sequencing methods. The validation study showed that stable miRNAs are suitable reference genes for RT-qPCR analysis of miRNA expression. Applying RT-qPCR we have identified

  5. Flesh quality and biochemistry of light-manipulated Atlantic cod (Gadus morhua) and the significance of collagen cross-links on fillet firmness and gaping.

    Science.gov (United States)

    Hagen, Ørjan; Johnsen, Chris André

    2016-01-01

    The aim of our study was to investigate whether light-manipulation, causing accelerated or delayed maturation, could be used as a tool to improve fillet gaping score and texture of farmed cod (Gadus morhua L.) harvested during summer. Control and accelerated groups had completed spawning by the time of harvest, and expressed sexual dimorphism in various biometric and flesh quality parameters. Pyridinoline cross-links, a key biochemical parameter investigated, were positively correlated with texture (r(2) = 0.4), as also were cathepsin B&L and sex. Gaping was also impacted by pyridinoline cross-links, together with body mass and maturation. Interestingly, the level of gaping was significantly reduced with a pyridinoline cross-link concentration of >2500 pmols g(-1) dry mass. In conclusion, light-manipulation can be used as a tool to improve flesh texture of farmed cod with a low gaping score, but with compromise of increased dress out percentage for the accelerated group. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Dynamic expression profiles of virus-responsive and putative antimicrobial peptide-encoding transcripts during Atlantic cod (Gadus morhua) embryonic and early larval development.

    Science.gov (United States)

    Rise, Matthew L; Hall, Jennifer R; Alcock, Brian P; Hori, Tiago S

    2012-11-10

    Early life stage mortality is one of the problems faced by Atlantic cod aquaculture. However, our understanding of immunity in early life stage fish is still incomplete, and the information available is restricted to a few species. In the present work we investigated the expression of immune-relevant transcripts in Atlantic cod during early development. The transcripts subjected to QPCR analysis in the present study were previously identified as putative anti-viral or anti-bacterial genes in Atlantic cod using suppression subtractive hybridization (SSH) libraries, QPCR, and/or microarrays. Of the 11 genes involved in this study, only atf3, cxc chemokine and gaduscidin-1 were not detected at the transcript level in all developmental stages investigated from unfertilized egg to early larval stage. Adam22, hamp, il8, irf1, irf7, lgp2, sacsin, and stat1 transcripts were detected in unfertilized egg and 7h post-fertilization (~2-cell stage) embryos, showing maternal contribution of these immune-relevant transcripts to the early embryonic transcriptome. The Atlantic cod genes included in this study presented diverse transcript expression profiles throughout embryonic and early larval development. For example, adam22 and sacsin transcripts rose abruptly during blastula/gastrula stage and were then expressed at relatively high levels through subsequent embryonic and early larval developmental stages. A peak in irf1 and irf7 transcript expression during early segmentation suggests that these interferon pathway genes play developmental stage-specific roles during cod embryogenesis. Stat1 had increasing transcript expression throughout blastula/gastrula, segmentation, and early larval developmental stages. Atf3, cxc chemokine, gaduscidin-1, and il8 transcripts rose approximately 2-3 fold during hatching, supporting the hypothesis that there is preparation at the immune-relevant transcript expression level to deal with environmental pathogens that may be encountered during

  7. Review of western Baltic cod (Gadus morhua) recruitment dynamics

    DEFF Research Database (Denmark)

    Hüssy, Karin

    2011-01-01

    Important processes in the recruitment dynamics of western Baltic cod (Gadus morhua) are identified. Spawning areas are in the deep, saline waters below 20–40 m, depending on area topography. Spatial distribution remains relatively stable over time. Peak spawning shows an area-specific pattern...

  8. New species in the genus Francisella (Gammaproteobacteria; Francisellaceae); Francisella piscicida sp. nov. isolated from cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Ottem, Karl F; Nylund, Are; Karlsbakk, Egil

    2007-01-01

    A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S-5S intergenic spacer, 5S rDNA, Fop...

  9. New species in the genus Francisella (Gammaproteobacteria; Francisellaceae); Francisella piscicida sp. nov. isolated from cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Ottem, Karl F; Nylund, Are; Karlsbakk, Egil

    2007-01-01

    A Francisella strain, GM2212, previously isolated from moribund farmed Atlantic cod (Gadus morhua) in Norway, is closely related to Francisella philomiragia among Francisella spp. according to its complete 16S rDNA, 16S-23S intergenic spacer, 23S rDNA, 23S-5S intergenic spacer, 5S rDNA, FopA, lip...

  10. Discrimination between weaned and unweaned Atlantic cod (Gadus morhua in capture-based aquaculture (CBA by X-ray imaging and radio-frequency metal detector.

    Directory of Open Access Journals (Sweden)

    Ekrem Misimi

    Full Text Available The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg in the small scale capture-based aquaculture (CBA. Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60-70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups - unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented.

  11. Discrimination between Weaned and Unweaned Atlantic Cod (Gadus morhua) in Capture-Based Aquaculture (CBA) by X-Ray Imaging and Radio-Frequency Metal Detector

    Science.gov (United States)

    Misimi, Ekrem; Martinsen, Svein; Mathiassen, John Reidar; Erikson, Ulf

    2014-01-01

    The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg) in the small scale capture-based aquaculture (CBA). Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60–70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups – unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band) and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented. PMID:24743448

  12. Discrimination between weaned and unweaned Atlantic cod (Gadus morhua) in capture-based aquaculture (CBA) by X-ray imaging and radio-frequency metal detector.

    Science.gov (United States)

    Misimi, Ekrem; Martinsen, Svein; Mathiassen, John Reidar; Erikson, Ulf

    2014-01-01

    The aim of this study was to investigate the feasibility of two detection methods for use in discrimination and sorting of adult Atlantic cod (about 2 kg) in the small scale capture-based aquaculture (CBA). Presently, there is no established method for discrimination of weaned and unweaned cod in CBA. Generally, 60-70% of the wild-caught cod in the CBA are weaned into commercial dry feed. To increase profitability for the fish farmers, unweaned cod must be separated from the stock, meaning the fish must be sorted into two groups - unweaned and weaned from moist feed. The challenges with handling of large numbers of fish in cages, defined the limits of the applied technology. As a result, a working model was established, focusing on implementing different marking materials added to the fish feed, and different technology for detecting the feed presence in the fish gut. X-ray imaging in two modes (planar and dual energy band) and sensitive radio-frequency metal detection were the detection methods that were chosen for the investigations. Both methods were tested in laboratory conditions using dead fish with marked feed inserted into the gut cavity. In particular, the sensitive radio-frequency metal detection method with carbonyl powder showed very promising results in detection of marked feed. Results show also that Dual energy band X-ray imaging may have potential for prediction of fat content in the feed. Based on the investigations it can be concluded that both X-ray imaging and sensitive radio-frequency metal detector technology have the potential for detecting cod having consumed marked feed. These are all technologies that may be adapted to large scale handling of fish from fish cages. Thus, it may be possible to discriminate between unweaned and weaned cod in a large scale grading situation. Based on the results of this study, a suggestion for evaluation of concept for in-situ sorting system is presented.

  13. Feeding opportunities of larval and juvenile cod (Gadus morhua) in a Greenlandic fjord: temporal and spatial linkages between cod and their preferred prey

    DEFF Research Database (Denmark)

    Swalethorp, Rasmus; Kjellerup, Sanne; Malanski, Evandro

    2014-01-01

    preferences of the early-life stages of Atlantic cod (Gadus morhua) to quantify the availability of prey during a spring-summer season in a West Greenlandic fjord. We hypothesized that abundances of larval and juvenile cod at size were synchronized to optimal availability of preferred prey in space and time....... The present analysis is based on nine cruises each covering 5 stations visited between 24 May and 5 August 2010 comparing zooplankton abundance, cod gut content and distribution patterns. Cod 4–25 mm in length preferred prey of about 5 % of their own length. During ontogeny, their preferences changed from...

  14. Uptake and tissue distribution of C{sub 4}-C{sub 7} alkylphenols in Atlantic cod (Gadus morhua): Relevance for biomonitoring of produced water discharges from oil production

    Energy Technology Data Exchange (ETDEWEB)

    Sundt, Rolf C. [IRIS-International Research Institute of Stavanger, P.O. Box 8046, N-4068 Stavanger (Norway)], E-mail: rolf.sundt@iris.no; Baussant, Thierry [IRIS-International Research Institute of Stavanger, P.O. Box 8046, N-4068 Stavanger (Norway); Beyer, Jonny [IRIS-International Research Institute of Stavanger, P.O. Box 8046, N-4068 Stavanger (Norway); University of Stavanger, N-4036 Stavanger (Norway)

    2009-01-15

    The sensitivity of different tissues for assessment of chronic low-dose environmental exposure of fish to alkylphenols (APs) was investigated. We exposed Atlantic cod (Gadus morhua) in the laboratory to tritium labelled 4-tert-butylphenol, 4n-pentylphenol, 4n-hexylphenol, and 4n-heptylphenol via seawater (8 ng/l) and via contaminated feed (5 {mu}g/kg fish per day). Measurements of different fish tissues during eight days of exposure and eight subsequent days of recovery revealed that APs administered via spiked seawater were readily taken up whereas the uptake was far less efficient when APs were administered in spiked feed. AP residues were mainly located in the bile fluid whereas the concentrations in liver were very low, indicating a rapid excretion and the liver-bile axis to be the major route of elimination. The biological half-life of APs in the exposed cod was short, between 10 and 20 h. Our study shows that in connection with biomonitoring of AP exposure in fish, assessment of AP metabolites in bile fluid is a more sensitive tool than detection of parent AP levels in liver or other internal tissues.

  15. Historical changes in genotypic frequencies at the Pantophysin locus in Atlantic cod (Gadus morhua) in Icelandic waters: evidence of fisheries-induced selection?

    Science.gov (United States)

    Jakobsdóttir, Klara B; Pardoe, Heidi; Magnússon, Árni; Björnsson, Höskuldur; Pampoulie, Christophe; Ruzzante, Daniel E; Marteinsdóttir, Guðrún

    2011-01-01

    The intense fishing mortality imposed on Atlantic cod in Icelandic waters during recent decades has resulted in marked changes in stock abundance, as well as in age and size composition. Using a molecular marker known to be under selection (Pan I) along with a suite of six neutral microsatellite loci, we analysed an archived data set and revealed evidence of distinct temporal changes in the frequencies of genotypes at the Pan I locus among spawning Icelandic cod, collected between 1948 and 2002, a period characterized by high fishing pressure. Concurrently, temporal stability in the composition of the microsatellite loci was established within the same data set. The frequency of the Pan IBB genotype decreased over a period of six decades, concomitant with considerable spatial and technical changes in fishing effort that resulted in the disappearance of older individuals from the fishable stock. Consequently, these changes have likely led to a change in the genotype frequencies at this locus in the spawning stock of Icelandic cod. The study highlights the value of molecular genetic approaches that combine functional and neutral markers examined in the same set of individuals for investigations of the selective effects of harvesting and reiterates the need for an evolutionary dimension to fisheries management. PMID:25568005

  16. Historical changes in genotypic frequencies at the Pantophysin locus in Atlantic cod (Gadus morhua) in Icelandic waters: evidence of fisheries-induced selection?

    Science.gov (United States)

    Jakobsdóttir, Klara B; Pardoe, Heidi; Magnússon, Árni; Björnsson, Höskuldur; Pampoulie, Christophe; Ruzzante, Daniel E; Marteinsdóttir, Guðrún

    2011-07-01

    The intense fishing mortality imposed on Atlantic cod in Icelandic waters during recent decades has resulted in marked changes in stock abundance, as well as in age and size composition. Using a molecular marker known to be under selection (Pan I) along with a suite of six neutral microsatellite loci, we analysed an archived data set and revealed evidence of distinct temporal changes in the frequencies of genotypes at the Pan I locus among spawning Icelandic cod, collected between 1948 and 2002, a period characterized by high fishing pressure. Concurrently, temporal stability in the composition of the microsatellite loci was established within the same data set. The frequency of the Pan I(BB) genotype decreased over a period of six decades, concomitant with considerable spatial and technical changes in fishing effort that resulted in the disappearance of older individuals from the fishable stock. Consequently, these changes have likely led to a change in the genotype frequencies at this locus in the spawning stock of Icelandic cod. The study highlights the value of molecular genetic approaches that combine functional and neutral markers examined in the same set of individuals for investigations of the selective effects of harvesting and reiterates the need for an evolutionary dimension to fisheries management.

  17. Pre-digestion of dietary lipids has only minor effects on absorption, retention and metabolism in larval stages of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Hamre, K; Lukram, I M; Rønnestad, I; Nordgreen, A; Saele, O

    2011-03-01

    The hypothesis of the present study was that cod larvae have a limitation in lipid digestion, and that absorption of lipids would increase by pre-hydrolysation. The diets used were designed to contain 15% lipid, of which 40% was phosphatidylcholine (PC) and 60 % was TAG. Cod larvae (40d post hatch (dph)) were fed a single meal where either PC or TAG was radioactively labelled, and the labelled PC or TAG was either intact or hydrolysed (pre-digested). The larvae were then incubated individually in chambers with collection of CO2 for 10 h. The following fractions were analysed for radioactivity: the incubation water (evacuated feed); the intestine; the body; the CO2 trap. The larvae ate a 16-29 μg diet, equivalent to 3·4-5·2 % of dry body weight. In the whole population, 0-16% of the lipid was evacuated. The larvae that had eaten less than 1·9-2·7 μg lipid absorbed close to 100% of the lipid, absorption being defined conservatively as the amount contained in the carcass and CO2, excluding the intestinal tissue. In these larvae, approximately 100 % of the absorbed lipid was also catabolised. In the larvae that ingested more than 1·9-2·7 μg lipid, there was a linear reduction in lipid absorption to a minimum of 55% at the highest lipid intakes parallel to an increasing retention of lipids in the carcass. There were only minor differences in digestion, absorption, retention and metabolism of lipids between the larvae fed the different diets, and the larvae tended to retain lipid classes as they were present in the feed. The study shows that 40-dph Atlantic cod larvae have an efficient utilisation of dietary lipids supplied as intact PC and TAG.

  18. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae — can we identify the underlying factors?

    Science.gov (United States)

    van der Meeren, Terje; Rønnestad, Ivar; Mangor-Jensen, Anders; Galloway, Trina F.; Kjørsvik, Elin; Hamre, Kristin

    2015-01-01

    The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1), groups of cod larvae were fed either (a) natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b) enriched rotifers followed by Artemia (the intensive group). In the second experiment (Exp-2), two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers) throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5) after the fish had been fed the same formulated diet for approximately 2 weeks. PMID:26038712

  19. Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L. larvae — can we identify the underlying factors?

    Directory of Open Access Journals (Sweden)

    Ørjan Karlsen

    2015-05-01

    Full Text Available The current commercial production protocols for Atlantic cod depend on enriched rotifers and Artemia during first-feeding, but development and growth remain inferior to fish fed natural zooplankton. Two experiments were conducted in order to identify the underlying factors for this phenomenon. In the first experiment (Exp-1, groups of cod larvae were fed either (a natural zooplankton, mainly copepods, increasing the size of prey as the larvae grew or (b enriched rotifers followed by Artemia (the intensive group. In the second experiment (Exp-2, two groups of larvae were fed as in Exp-1, while a third group was fed copepod nauplii (approximately the size of rotifers throughout the larval stage. In both experiments, growth was not significantly different between the groups during the first three weeks after hatching, but from the last part of the rotifer feeding period and onwards, the growth of the larvae fed copepods was higher than that of the intensive group. In Exp-2, the growth was similar between the two copepod groups during the expeimental period, indicating that nutrient composition, not prey size caused the better growth on copepods. Analyses of the prey showed that total fatty acid composition and the ratio of phospholipids to total lipids was slightly different in the prey organisms, and that protein, taurine, astaxanthin and zinc were lower on a dry weight basis in rotifers than in copepods. Other measured nutrients as DHA, all analysed vitamins, manganese, copper and selenium were similar or higher in the rotifers. When compared to the present knowledge on nutrient requirements, protein and taurine appeared to be the most likely limiting nutrients for growth in cod larvae fed rotifers and Artemia. Larvae fed rotifers/Artemia had a higher whole body lipid content than larvae fed copepods at the end of the experiment (stage 5 after the fish had been fed the same formulated diet for approximately 2 weeks.

  20. Cod (Gadus morhua) rearing attempts in France

    OpenAIRE

    Suquet, Marc; Omnes, Marie-helene; Normant, Yvon; Petton, Bruno; Severe, Armelle; Fauvel, Christian; Barone, Herve; Quemener, Loic; Buchet, Vincent; Pasco, Laurent; Menard, E.; Gaignon, Jean-louis

    2002-01-01

    Because of its rapid growth, its good reputation and the promising aquaculture experiences conducted in Norway and Scotland, cod is considered as a good candidate for cold water aquaculture. The aim of this paper is to present the work carried out in France since 1999: the selection of cod as a promising candidate for aquaculture and the assessment of its rearing performances in this environment.

  1. The Ontogeny and Brain Distribution Dynamics of the Appetite Regulators NPY, CART and pOX in Larval Atlantic Cod (Gadus morhua L.).

    Science.gov (United States)

    Le, Hoang T M D; Angotzi, Anna Rita; Ebbesson, Lars O E; Karlsen, Ørjan; Rønnestad, Ivar

    2016-01-01

    Similar to many marine teleost species, Atlantic cod undergo remarkable physiological changes during the early life stages with concurrent and profound changes in feeding biology and ecology. In contrast to the digestive system, very little is known about the ontogeny and the localization of the centers that control appetite and feed ingestion in the developing brain of fish. We examined the expression patterns of three appetite regulating factors (orexigenic: neuropeptide Y, NPY; prepro-orexin, pOX and anorexigenic: cocaine- and amphetamine-regulated transcript, CART) in discrete brain regions of developing Atlantic cod using chromogenic and double fluorescent in situ hybridization. Differential temporal and spatial expression patterns for each appetite regulator were found from first feeding (4 days post hatch; dph) to juvenile stage (76 dph). Neurons expressing NPY mRNA were detected in the telencephalon (highest expression), diencephalon, and optic tectum from 4 dph onward. CART mRNA expression had a wider distribution along the anterior-posterior brain axis, including both telencephalon and diencephalon from 4 dph. From 46 dph, CART transcripts were also detected in the olfactory bulb, region of the nucleus of medial longitudinal fascicle, optic tectum and midbrain tegmentum. At 4 and 20 dph, pOX mRNA expression was exclusively found in the preoptic region, but extended to the hypothalamus at 46 and 76 dph. Co-expression of both CART and pOX genes were also observed in several hypothalamic neurons throughout larval development. Our results show that both orexigenic and anorexigenic factors are present in the telencephalon, diencephalon and mesencephalon in cod larvae. The telencephalon mostly contains key factors of hunger control (NPY), while the diencephalon, and particularly the hypothalamus may have a more complex role in modulating the multifunctional control of appetite in this species. As the larvae develop, the overall progression in temporal and

  2. The Ontogeny and Brain Distribution Dynamics of the Appetite Regulators NPY, CART and pOX in Larval Atlantic Cod (Gadus morhua L..

    Directory of Open Access Journals (Sweden)

    Hoang T M D Le

    Full Text Available Similar to many marine teleost species, Atlantic cod undergo remarkable physiological changes during the early life stages with concurrent and profound changes in feeding biology and ecology. In contrast to the digestive system, very little is known about the ontogeny and the localization of the centers that control appetite and feed ingestion in the developing brain of fish. We examined the expression patterns of three appetite regulating factors (orexigenic: neuropeptide Y, NPY; prepro-orexin, pOX and anorexigenic: cocaine- and amphetamine-regulated transcript, CART in discrete brain regions of developing Atlantic cod using chromogenic and double fluorescent in situ hybridization. Differential temporal and spatial expression patterns for each appetite regulator were found from first feeding (4 days post hatch; dph to juvenile stage (76 dph. Neurons expressing NPY mRNA were detected in the telencephalon (highest expression, diencephalon, and optic tectum from 4 dph onward. CART mRNA expression had a wider distribution along the anterior-posterior brain axis, including both telencephalon and diencephalon from 4 dph. From 46 dph, CART transcripts were also detected in the olfactory bulb, region of the nucleus of medial longitudinal fascicle, optic tectum and midbrain tegmentum. At 4 and 20 dph, pOX mRNA expression was exclusively found in the preoptic region, but extended to the hypothalamus at 46 and 76 dph. Co-expression of both CART and pOX genes were also observed in several hypothalamic neurons throughout larval development. Our results show that both orexigenic and anorexigenic factors are present in the telencephalon, diencephalon and mesencephalon in cod larvae. The telencephalon mostly contains key factors of hunger control (NPY, while the diencephalon, and particularly the hypothalamus may have a more complex role in modulating the multifunctional control of appetite in this species. As the larvae develop, the overall progression in

  3. Does DNA extraction affect the physical and chemical composition of historical cod (Gadus morhua) otoliths?

    DEFF Research Database (Denmark)

    Therkildsen, Nina Overgaard; Eg Nielsen, Einar; Hüssy, Karin

    2010-01-01

    applications. We examined the effects of three different DNA extraction methods on the elemental composition, the morphology, and the clarity of annual growth increments for successful age estimation of Atlantic cod (Gadus morhua) otoliths that had been archived for 0–31 years. The three extraction methods...... yielded DNA of comparable quality, and none of the methods caused major damage to the otoliths. Of the element concentrations measured, only Mg and Rb showed considerable changes resulting from DNA extraction. The physical properties of the otolith (morphology and clarity of annual growth increments) were...

  4. Transcriptional responses in juvenile Atlantic cod (Gadus morhua) after exposure to mercury-contaminated sediments obtained near the wreck of the German WW2 submarine U-864, and from Bergen Harbor, Western Norway.

    Science.gov (United States)

    Olsvik, Pål A; Brattås, Marianne; Lie, Kai K; Goksøyr, Anders

    2011-04-01

    The main aim of the present work was to investigate the effects of mercury (Hg)-enriched sediments on fish. Sediments near the sunken German WW2 submarine U-864, which according to historical documents included 67 tons of metallic Hg in its cargo, are enriched of Hg leaking from the wreckage. Juvenile Atlantic cod (Gadus morhua) were exposed to two field-collected polluted sediments (U-864: inorganic Hg and Bergen Harbor (Vågen): inorganic Hg, PCB and PAH) or two comparable reference sediments for 5 weeks in the laboratory, and transcriptional responses evaluated in gills and liver. Gills of fish exposed to the Hg-enriched sunken WW2 submarine U-864 sediment contained four fold higher Hg levels compared to the control fish. An increase in Hg content in liver in the U-864 fish was also observed. The transcriptional results showed that calreticulin, HSP70 and heme oxygenase mRNA were significantly up-regulated in gills in fish exposed to the Hg-enriched sediments, whereas calreticulin, heme oxygenase, transferrin and WAP65 were significantly up-regulated and glutathione peroxidase 4B and zona pellucida 3 were significantly down-regulated in liver tissue. In gills and liver of cod exposed to the mixed-contaminated Vågen sediment, CYP1A showed the highest induction. In conclusion, the experiment shows that sediment-bound Hg is available to the fish and affects the transcription of oxidative stress responsive enzymes, suggesting that the Hg-enriched sediments may negatively affect the local wildlife. Furthermore, the mixed contaminated sediments of Vågen affected similar responses in addition to Ah-receptor mediated responses reflecting exposure to PAHs and PCBs. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Cod Collapse and the Climate in the North Atlantic

    Science.gov (United States)

    Meng, K. C.; Oremus, K. L.; Gaines, S.

    2014-12-01

    Effective fisheries management requires forecasting population changes. We find a negative relationship between the North Atlantic Oscillation (NAO) index and subsequently surveyed biomass and catch of Atlantic cod, Gadus morhua, off the New England coast. A 1-unit NAO increase is associated with a 17% decrease in surveyed biomass of age-1 cod the following year. This relationship persists as the cod mature, such that observed NAO can be used to forecast future adult biomass. We also document that an NAO event lowers catch for up to 15 years afterward. In contrast to forecasts by existing stock assessment models, our NAO-driven statistical model successfully hindcasts the recent collapse of New England cod fisheries following strong NAO events in 2007 and 2008 (see figure). This finding can serve as a template for forecasting other fisheries affected by climatic conditions.

  6. Organochlorines including polychlorinated biphenyls in muscle, liver, and ovaries of cod, Gadus morhua

    Energy Technology Data Exchange (ETDEWEB)

    Hellou, J.; Warren, W.G.; Payne, J.F. (Northwest Atlantic Fisheries Centre, St. John' s, Newfoundland (Canada))

    1993-11-01

    Twenty-three specific organochlorine contaminants and polychlorinated biphenyls (PCBs), measured as three Aroclor standards were analyzed in muscle, liver, and ovaries of cod, Gadus morhua, collected in the Northwest Atlantic. In general, contaminants were undetectable in muscle tissue, while concentrations were 10 times lower in ovaries than liver (wet weight). Comparison of results to other locations indicated a similarity between the ratio of the concentrations of p,p'-DDE, p,p'-DDD and p,p'-DDT, in liver of cod from the northern North Sea and from the Northwest Atlantic, although with lower levels in the present study. The ratio of alpha-HCH and gamma-HCH was between that of the central and northern North Sea. Similar ratios tend to indicate similar residence times in the atmosphere, from source to sampling area. Comparison of sigma PCB and sigma DDT in the liver of cod from various geographical locations showed the following general trend in concentrations: Arctic, Northwest Atlantic, West Atlantic, Norway < North Baltic, Nova Scotia, North Sea < South Baltic. It was observed that if the liver concentration of one compound was low (high), there was a tendency for all compounds to be low (high). Cluster analysis of organochlorines in liver pointed to the presence of four basic clusters, which could reflect similar physical chemical properties within a group. Concentrations of organochlorines in ovaries were below levels expected to affect egg and larval viability.

  7. Differential impacts of elevated CO2 and acidosis on the energy budget of gill and liver cells from Atlantic cod, Gadus morhua.

    Science.gov (United States)

    Stapp, L S; Kreiss, C M; Pörtner, H O; Lannig, G

    2015-09-01

    Ocean acidification impacts fish and other marine species through increased seawater PCO2 levels (hypercapnia). Knowledge of the physiological mechanisms mediating effects in various tissues of fish is incomplete. Here we tested the effects of extracellular hypercapnia and acidosis on energy metabolism of gill and liver cells of Atlantic cod. Exposure media mimicked blood conditions in vivo, either during normo- or hypercapnia and at control or acidic extracellular pH (pHe). We determined metabolic rate and energy expenditure for protein biosynthesis, Na(+)/K(+)-ATPase and H(+)-ATPase and considered nutrition status by measurements of metabolic rate and protein biosynthesis in media with and without free amino acids (FAA). Addition of FAA stimulated hepatic but not branchial oxygen consumption. Normo- and hypercapnic acidosis as well as hypercapnia at control pHe depressed metabolic stimulation of hepatocytes. In gill cells, acidosis depressed respiration independent of PCO2 and FAA levels. For both cell types, depressed respiration was not correlated with the same reduction in energy allocated to protein biosynthesis or Na(+)/K(+)-ATPase. Hepatic energy expenditure for protein synthesis and Na(+)/K(+)-ATPase was even elevated at acidic compared to control pHe suggesting increased costs for ion regulation and cellular reorganization. Hypercapnia at control pHe strongly reduced oxygen demand of branchial Na(+)/K(+)-ATPase with a similar trend for H(+)-ATPase. We conclude that extracellular acidosis triggers metabolic depression in gill and metabolically stimulated liver cells. Additionally, hypercapnia itself seems to limit capacities for metabolic usage of amino acids in liver cells while it decreases the use and costs of ion regulatory ATPases in gill cells. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Impact of long-term moderate hypercapnia and elevated temperature on the energy budget of isolated gills of Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Kreiss, Cornelia M; Michael, Katharina; Bock, Christian; Lucassen, Magnus; Pörtner, Hans-O

    2015-04-01

    Effects of severe hypercapnia have been extensively studied in marine fishes, while knowledge on the impacts of moderately elevated CO2 levels and their combination with warming is scarce. Here we investigate ion regulation mechanisms and energy budget in gills from Atlantic cod acclimated long-term to elevated PCO2 levels (2500 μatm) and temperature (18°C). Isolated perfused gill preparations were established to determine gill thermal plasticity during acute exposures (10-22°C) and in vivo costs of Na(+)/K(+)-ATPase activity, protein and RNA synthesis. Maximum enzyme capacities of F1Fo-ATPase, H(+)-ATPase and Na(+)/K(+)-ATPase were measured in vitro in crude gill homogenates. After whole animal acclimation to elevated PCO2 and/or warming, branchial oxygen consumption responded more strongly to acute temperature change. The fractions of gill respiration allocated to protein and RNA synthesis remained unchanged. In gills of fish CO2-exposed at both temperatures, energy turnover associated with Na(+)/K(+)-ATPase activity was reduced by 30% below rates of control fish. This contrasted in vitro capacities of Na(+)/K(+)-ATPase, which remained unchanged under elevated CO2 at 10°C, and earlier studies which had found a strong upregulation under severe hypercapnia. F1Fo-ATPase capacities increased in hypercapnic gills at both temperatures, whereas Na(+)/K(+)ATPase and H(+)-ATPase capacities only increased in response to elevated CO2 and warming indicating the absence of thermal compensation under CO2. We conclude that in vivo ion regulatory energy demand is lowered under moderately elevated CO2 levels despite the stronger thermal response of total gill respiration and the upregulation of F1Fo-ATPase. This effect is maintained at elevated temperature. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. A millennium of north-east Atlantic cod juvenile growth trajectories inferred from archaeological otoliths.

    Directory of Open Access Journals (Sweden)

    Guðbjörg Ásta Ólafsdóttir

    Full Text Available Archaeological excavations of historical fishing sites across the North Atlantic have recovered high quantities of Atlantic cod (Gadus morhua bones. In the current study we use Atlantic cod otoliths from archaeological excavations of a historical fishing sites in north-west Iceland, dated to AD 970 -AD 1910 to examine historical growth trajectories of cod. No large scale growth variations or shifts in growth patterns were observed in the current chronologies, supporting the stability of historical Atlantic cod growth trajectories. The most significant variation in growth patterns was consistent with those that have been observed in recent times, for example, reduced early juvenile growth during periods of colder ocean temperature. The current results represent a high resolution chronological record of north-east Atlantic cod growth, greatly increasing the prior temporal range of such data, thereby providing a valuable baseline for a broad range of studies on Atlantic cod growth.

  10. A millennium of north-east Atlantic cod juvenile growth trajectories inferred from archaeological otoliths.

    Science.gov (United States)

    Ólafsdóttir, Guðbjörg Ásta; Pétursdóttir, Gróa; Bárðarson, Hlynur; Edvardsson, Ragnar

    2017-01-01

    Archaeological excavations of historical fishing sites across the North Atlantic have recovered high quantities of Atlantic cod (Gadus morhua) bones. In the current study we use Atlantic cod otoliths from archaeological excavations of a historical fishing sites in north-west Iceland, dated to AD 970 -AD 1910 to examine historical growth trajectories of cod. No large scale growth variations or shifts in growth patterns were observed in the current chronologies, supporting the stability of historical Atlantic cod growth trajectories. The most significant variation in growth patterns was consistent with those that have been observed in recent times, for example, reduced early juvenile growth during periods of colder ocean temperature. The current results represent a high resolution chronological record of north-east Atlantic cod growth, greatly increasing the prior temporal range of such data, thereby providing a valuable baseline for a broad range of studies on Atlantic cod growth.

  11. Seasonal and annual variation in the diet of Atlantic cod (Gadus morhua) in relation to the abundance of capelin (Mallotus villosus) off eastern Newfoundland, Canada

    Science.gov (United States)

    Methven, David A.; Piatt, John F.

    1989-01-01

    The importance of capelin as prey for cod has long been known (Thompson, 1943; and see Lilly (1987) for a review); however, no studies have been conducted on how the highly dynamic seasonal and yearly variations in capelin abundance affect cod diet. We studied the occurrence of capelin in cod stomachs in relation to the relative abundance of capelin at Witless Bay, Newfoundland (47°15’N 52°46’W), during June, July and August, 1982-1984. The mean number of capelin per stomach and the per cent occurrence of stomachs containing capelin were determined for each collection of stomachs. A total of 680 stomachs were examined. Cod were sampled from those caught in gillnets by fishermen and averaged 66 cm ± 8 (s.d.) in 1983 and 62 cm ± 8 (s.d.) in 1984. Relative abundance of capelin in the local habitat was determined by conducting hydroacoustic surveys around Gull Island in Witless Bay, the same area where cod were collected for stomach content analysis. Only hydroacoustic surveys conducted within three days of cod stomach collections were analyzed. Further details of hydroacoustic surveys including quantifications of acoustic echograms are described in Piatt (1989).

  12. Heat-shock responsive genes identified and validated in Atlantic cod (Gadus morhua) liver, head kidney and skeletal muscle using genomic techniques.

    Science.gov (United States)

    Hori, Tiago S; Gamperl, A Kurt; Afonso, Luis Ob; Johnson, Stewart C; Hubert, Sophie; Kimball, Jennifer; Bowman, Sharen; Rise, Matthew L

    2010-01-28

    Daily and seasonal changes in temperature are challenges that fish within aquaculture settings cannot completely avoid, and are known to elicit complex organismal and cellular stress responses. We conducted a large-scale gene discovery and transcript expression study in order to better understand the genes that are potentially involved in the physiological and cellular aspects of stress caused by heat-shock. We used suppression subtractive hybridization (SSH) cDNA library construction and characterization to identify transcripts that were dysregulated by heat-shock in liver, skeletal muscle and head kidney of Atlantic cod. These tissues were selected due to their roles in metabolic regulation, locomotion and growth, and immune function, respectively. Fish were exposed for 3 hours to an 8 degrees C elevation in temperature, and then allowed to recover for 24 hours at the original temperature (i.e. 10 degrees C). Tissue samples obtained before heat-shock (BHS), at the cessation of heat-shock (CS), and 3, 12, and 24 hours after the cessation of heat-shock (ACS), were used for reciprocal SSH library construction and quantitative reverse transcription - polymerase chain reaction (QPCR) analysis of gene expression using samples from a group that was transferred but not heat-shocked (CT) as controls. We sequenced and characterized 4394 ESTs (1524 from liver, 1451 from head kidney and 1419 from skeletal muscle) from three "forward subtracted" libraries (enriched for genes up-regulated by heat-shock) and 1586 from the liver "reverse subtracted" library (enriched for genes down-regulated by heat-shock), for a total of 5980 ESTs. Several cDNAs encoding putative chaperones belonging to the heat-shock protein (HSP) family were found in these libraries, and "protein folding" was among the gene ontology (GO) terms with the highest proportion in the libraries. QPCR analysis of HSP90alpha and HSP70-1 (synonym: HSPA1A) mRNA expression showed significant up-regulation in all three

  13. Heat-shock responsive genes identified and validated in Atlantic cod (Gadus morhua liver, head kidney and skeletal muscle using genomic techniques

    Directory of Open Access Journals (Sweden)

    Kimball Jennifer

    2010-01-01

    Full Text Available Abstract Background Daily and seasonal changes in temperature are challenges that fish within aquaculture settings cannot completely avoid, and are known to elicit complex organismal and cellular stress responses. We conducted a large-scale gene discovery and transcript expression study in order to better understand the genes that are potentially involved in the physiological and cellular aspects of stress caused by heat-shock. We used suppression subtractive hybridization (SSH cDNA library construction and characterization to identify transcripts that were dysregulated by heat-shock in liver, skeletal muscle and head kidney of Atlantic cod. These tissues were selected due to their roles in metabolic regulation, locomotion and growth, and immune function, respectively. Fish were exposed for 3 hours to an 8°C elevation in temperature, and then allowed to recover for 24 hours at the original temperature (i.e. 10°C. Tissue samples obtained before heat-shock (BHS, at the cessation of heat-shock (CS, and 3, 12, and 24 hours after the cessation of heat-shock (ACS, were used for reciprocal SSH library construction and quantitative reverse transcription - polymerase chain reaction (QPCR analysis of gene expression using samples from a group that was transferred but not heat-shocked (CT as controls. Results We sequenced and characterized 4394 ESTs (1524 from liver, 1451 from head kidney and 1419 from skeletal muscle from three "forward subtracted" libraries (enriched for genes up-regulated by heat-shock and 1586 from the liver "reverse subtracted" library (enriched for genes down-regulated by heat-shock, for a total of 5980 ESTs. Several cDNAs encoding putative chaperones belonging to the heat-shock protein (HSP family were found in these libraries, and "protein folding" was among the gene ontology (GO terms with the highest proportion in the libraries. QPCR analysis of HSP90α and HSP70-1 (synonym: HSPA1A mRNA expression showed significant up

  14. The role of extracellular matrix components in pin bone attachments during storage-a comparison between farmed Atlantic salmon (Salmo salar) and cod (Gadus morhua L.).

    Science.gov (United States)

    Rønning, Sissel B; Østbye, Tone-Kari; Krasnov, Aleksei; Vuong, Tram T; Veiseth-Kent, Eva; Kolset, Svein O; Pedersen, Mona E

    2017-04-01

    Pin bones represent a major problem for processing and quality of fish products. Development of methods of removal requires better knowledge of the pin bones' attachment to the muscle and structures involved in the breakdown during loosening. In this study, pin bones from cod and salmon were dissected from fish fillets after slaughter or storage on ice for 5 days, and thereafter analysed with molecular methods, which revealed major differences between these species before and after storage. The connective tissue (CT) attaches the pin bone to the muscle in cod, while the pin bones in salmon are embedded in adipose tissue. Collagens, elastin, lectin-binding proteins and glycosaminoglycans (GAGs) are all components of the attachment site, and this differ between salmon and cod, resulting in a CT in cod that is more resistant to enzymatic degradation compared to the CT in salmon. Structural differences are reflected in the composition of transcriptome. Microarray analysis comparing the attachment sites of the pin bones with a reference muscle sample showed limited differences in salmon. In cod, on the other hand, the variances were substantial, and the gene expression profiles suggested difference in myofibre structure, metabolism and cell processes between the pin bone attachment site and the reference muscle. Degradation of the connective tissue occurs closest to the pin bones and not in the neighbouring tissue, which was shown using light microscopy. This study shows that the attachment of the pin bones in cod and salmon is different; therefore, the development of methods for removal should be tailored to each individual species.

  15. Comparison of protein expression in plasma from nonylphenol and bisphenol A-exposed Atlantic cod (Gadus morhua) and turbot (Scophthalmus maximus) by use of SELDI-TOF

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Bodil K. [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway)]. E-mail: Bodil.larsen@irisresearch.no; Bjornstad, Anne [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway); Sundt, Rolf C. [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway); Taban, Ingrid C. [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway); Pampanin, Daniela M. [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway); Andersen, Odd Ketil [International Research Institute of Stavanger (IRIS) AS, Mekjarvik 12, N-4070 Randaberg (Norway)

    2006-06-01

    The overall objective of this study was to compare the expression of plasma proteins in juvenile cod and turbot after a 3 week exposure to two different chemicals known to be estrogenic: 4-nonylphenol (NP, 29 {mu}g/L) and bisphenol A (BPA, 59 {mu}g/L). ProteinChip[reg] array technology in combination with surfaced enhanced laser desorption ionisation-time of flight (SELDI-TOF) was used to investigate general responses in plasma proteins. In addition, an indirect enzyme-linked immunosorbent assay (ELISA) was used to analyse two specific biomarkers of estrogenic exposure, vitellogenin (Vtg) and zona radiata protein (Zrp) in plasma. Both methods revealed clear species specific responses. In cod, 67% of significantly altered proteins showed the same response (up or down regulated) in NP and BPA exposed animals (males and females combined). The rest were either specific to NP (10%), BPA (19%) or they showed opposite responses to the two chemicals (4%). In contrast, only 20% of significantly altered proteins were common for NP and BPA exposed turbot: 60% were altered only in NP and 17% only in BPA. Furthermore, in BPA exposed cod, 77% of the responses were common for male and females, whereas turbot showed only 21% similarity for the two genders. However, NP exposed male and female turbot showed 88% similarity in responses. As gender was not determined in NP exposed cod, gender specific responses could not be determined. ELISA results supported that cod responded clearly to both chemicals as a large increase was observed in Vtg and Zrp levels. Turbot responded strongly to NP, but seemed only slightly affected by BPA. Overall, the results indicated that cod are more sensitive or respond with less specificity to estrogenic chemicals than turbot. The relatively large degree of common responses in NP and BPA exposed cod may indicate that in cod BPA have similar mode of action as NP. Generally, the results show the potential of SELDI-TOF as a tool for comparing multiple

  16. Large-scale sequence analyses of Atlantic cod.

    Science.gov (United States)

    Johansen, Steinar D; Coucheron, Dag H; Andreassen, Morten; Karlsen, Bård Ove; Furmanek, Tomasz; Jørgensen, Tor Erik; Emblem, Ase; Breines, Ragna; Nordeide, Jarle T; Moum, Truls; Nederbragt, Alexander J; Stenseth, Nils C; Jakobsen, Kjetill S

    2009-06-01

    The Atlantic cod (Gadus morhua) is a key species in the North Atlantic ecosystem and commercial fisheries, with increasing aquacultural production in several countries. A Norwegian effort to sequence the complete 0.9Gbp genome by the 454 pyrosequencing technology has been initiated and is in progress. Here we review recent progress in large-scale sequence analyses of the nuclear genome, the mitochondrial genome and genome-wide microRNA identification in the Atlantic cod. The nuclear genome will be de novo sequenced with 25 times oversampling. A total of 120 mitochondrial genomes, sampled from several locations in the North Atlantic, are being completely sequenced by Sanger technology in a high-throughput pipeline. These sequences will be included in a new database for maternal marker reference of Atlantic cod diversity. High-throughput 454 sequencing, as well as Evolutionary Image Array (EvoArray) informatics, is used to investigate the complete set of expressed microRNAs and corresponding mRNA targets in various developmental stages and tissues. Information about microRNA profiles will be essential in the understanding of transcriptome complexity and regulation. Finally, developments and perspectives of Atlantic cod aquaculture are discussed in the light of next-generation high-throughput sequence technologies.

  17. The blood chemical status of Atlantic cod Gadus morhua following capture by jig and demersal longline with differential hook removal methods.

    Science.gov (United States)

    Mandelman, J W; Morrison, R A; Cavin, J M; Farrington, M A

    2012-09-01

    Common haematological [haematocrit (Hct)], primary (serum cortisol) and secondary (serum glucose and plasma lactate) analytes were utilized to compare blood biochemical status of Gadus morhua captured rapidly by jig with that of G. morhua captured by commercial demersal longline. In general, the physiological status of G. morhua, despite blind hook times, was significantly more disrupted (pronounced haemo-concentration and significantly elevated concentrations of cortisol, glucose and lactate) following longline capture relative to capture by jig, while no differences were detected among longline-caught fish as a function of dehooking method (or concomitant extent of overt physical trauma). Blood profiles from the more stressed G. morhua, a possible function of more extended longline hook times, were similar to the most stressed values reported for this species. The results also demonstrate that, although acute blood biochemical status is an effective gauge of relative stress, it does not reflect physical injury status, which has been shown to exert a strong influence on delayed mortality in previous studies in this species. Thus, acute blood chemical status alone may not be the most complete predictor of mortality. Future studies should evaluate physiological repercussions from capture-handling against physical trauma during more extended post-release periods for this species. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  18. Food resource utilization by juvenile Baltic cod Gadus morhua : a mechanism potentially influencing recruitment success at the demersal juvenile stage?

    DEFF Research Database (Denmark)

    Hüssy, Karin; St. John, Michael; Böttcher, U.

    1997-01-01

    Pelagic and demersal juvenile Baltic cod Gadus morhua L. were collected during surveys in the Bornholm Basin (Baltic Sea) in autumn 1994. Stomach contents were examined for prey composition in order to evaluate the potential importance of the pelagic and demersal habitats for recruitment success....... Juvenile cod less than 40 mm fed exclusively on pelagic prey such as copepods and cladocerans. Between 40 and 50 mm the juveniles began to consume benthic prey such as mysids and amphipods; however, copepods were still the dominant food organisms. Between 50 and 70 mm the dominant prey items consumed were...... by pelagic and small demersal juveniles from this study differed from prey reported to be taken by juvenile cod of corresponding size in the Atlantic and the North Sea. However, prey organisms consumed by demersal juvenile Baltic cod larger than 90 mm were much smaller, and prey numbers much higher, than...

  19. Response of branchial Na(+)/K(+) ATPase to changes in ambient temperature in Atlantic cod (Gadus morhua) and whiting (Merlangius merlangus).

    Science.gov (United States)

    Michael, Katharina; Koschnick, Nils; Pörtner, Hans-O; Lucassen, Magnus

    2016-05-01

    The maintenance of ion and pH homeostasis despite changes in ambient temperature is crucial for ectothermic organisms. Thermal sensitivity of Na(+)/K(+) ATPase mRNA expression, protein expression and activity was determined in gills of North Sea cod (NC) and Northeastern Arctic cod (NEAC), acclimated for 6 weeks at 4 and 10 °C and compared to field samples of North Sea cod (sNC), acclimatized to early spring (4 °C) and summer (18 °C) conditions. The same analyses were conducted in gills of the confamiliar whiting, acclimated at 4 and 10 °C. Branchial Na(+)/K(+) ATPase capacities remained uncompensated at functional and protein levels in NC and NEAC at both acclimation temperatures. Na(+)/K(+) ATPase mRNA expression in NEAC acclimated at 10 °C was about twofold higher compared to NC, indicating some population-specific differentiation at this level. Lower Na(+)/K(+) ATPase capacities in gills of warm-acclimatized sNC at common assay temperatures indicate thermal compensation between seasonal extremes, and post-translational modifications contributed to this mitigation at high assay temperature. Together, cod compensates Na(+)/K(+) ATPase capacities on the warm edge of the thermal window and below 4 °C, respectively. In contrast, whiting Na(+)/K(+) ATPase capacities were cold compensated at 4 °C, supported by 1.5-fold higher mRNA and protein expression. Besides, capacities were lower in whiting compared to NC and NEAC at optimum temperature, which may be advantageous in terms of reduced maintenance cost, but at temperatures ≤4 °C, compensation may represent an energy trade-off to maintain homeostasis. The species-specific response of gadid Na(+)/K(+) ATPase indicates certain threshold temperatures beyond which compensation of the pump is elicited, possibly related to the different biogeography of these species.

  20. The role of extracellular matrix components in pin bone attachments during storage—a comparison between farmed Atlantic salmon (Salmo salar) and cod (Gadus morhua L.)

    OpenAIRE

    Rønning, Sissel Beate; Østbye, Tone-Kari K; Krasnov, Aleksei; Vuong, Tram Thu; Veiseth-Kent, Eva; Kolset, Svein Olav; Pedersen, Mona Elisabeth

    2016-01-01

    Pin bones represent a major problem for processing and quality of fish products. Development of methods of removal requires better knowledge of the pin bones? attachment to the muscle and structures involved in the breakdown during loosening. In this study, pin bones from cod and salmon were dissected from fish fillets after slaughter or storage on ice for 5?days, and thereafter analysed with molecular methods, which revealed major differences between these species before and after storage. T...

  1. Feeding ecology of age-0 walleye pollock (Gadus chalcogrammus) and Pacific cod (Gadus macrocephalus) in the southeastern Bering Sea

    Science.gov (United States)

    Strasburger, Wesley W.; Hillgruber, Nicola; Pinchuk, Alexei I.; Mueter, Franz J.

    2014-11-01

    Walleye pollock (Gadus chalcogrammus) and Pacific cod (Gadus macrocephalus) are of particular economic and ecological importance in the southeastern Bering Sea. The spatial and temporal overlap of early life stages of both species may explain their strongly correlated recruitment trends. Pelagic larvae and juveniles were collected during four research cruises in May, July and September of 2008, an exceptionally cold year, and their stomach contents were examined. Feeding success and diet composition of walleye pollock and Pacific cod were consistently different in spring, summer, and fall. Pacific cod larvae and juveniles always consumed larger and progressively fewer prey items per stomach than walleye pollock; this difference was particularly pronounced in the fall. Our data suggest that co-occurring early life stages of walleye pollock and Pacific cod were dividing prey resources rather than competing for them, at least during the exceptionally cold conditions in 2008 in the southeastern Bering Sea.

  2. [Crystallization of aqueous solutions of cryoprotectors from Atlantic cod and lake Gammarus].

    Science.gov (United States)

    Andreev, A A; Petropavlov, N N

    1996-01-01

    A comparative analysis of two types of cryoprotectants, antifreeze glycoproteins from Atlantic cod (Gadus morhua) and carbohydrates from hemolymph of amphypoid crustacean (Gammarus lacustris) has been performed. Both glycoprotein and carbohydrate antifreezes effectively decreased the freezing point of water solutions and diminished the size of ice crystals formed. Noncolligative and colligative mechanisms of action are characteristic correspondingly for glycoproteins and carbohydrates.

  3. The effect of external dummy transmitters on oxygen consumption and performance of swimming Atlantic cod

    DEFF Research Database (Denmark)

    Steinhausen, M.F.; Andersen, Niels Gerner; Steffensen, J.F.

    2006-01-01

    Decreased critical swimming speed and increased oxygen consumption (Mo-2) was found for externally tagged Atlantic cod Gadus morhua swimming at a high speed of 0 center dot 9 body length (total length, L-Gamma) s(-1). No difference was found in the standard metabolic rate, indicating...

  4. Atlantic Cod Show a Highly Variable Sensitivity to Electric-Induced Spinal Injuries

    NARCIS (Netherlands)

    Soetaert, M.; Haan, de D.; Verschueren, B.; Decostere, A.; Puvanendran, V.; Saunders, J.; Polet, H.; Chiers, K.

    2016-01-01

    Pulse trawling is the most promising alternative to conventional beam trawls targeting Sole Solea solea (also known as Solea vulgaris), but due to the electric fields created by electrotrawls spinal injuries are reported in gadoid round fishes such as Atlantic Cod Gadus morhua. This study aimed

  5. Recent trends in the abundance of plaice Pleuronectes platessa and cod Gadus morhua in shallow coastal waters of the Northeastern Atlantic continental shelf – a review

    DEFF Research Database (Denmark)

    Dutz, Jörg; Støttrup, Josianne Gatt; Stenberg, Claus

    2016-01-01

    responsible for any trends. At present, only a few studies exist on the trends of abundance of plaice or cod, namely from the Bay of Biscay, the North Sea and the Skagerrak/Kattegat. They suggest a declining abundance in coastal, shallow areas and – at least for plaice – a latitudinal gradient with an erosion...... of juveniles and adult fish to increasing seawater temperature are the main hypotheses for changes in distribution and abundance of both fish species in the North Sea/Bay of Biscay. However, temperature alone cannot explain the observed decline of fish in coastal areas, and the causes may be more complex...

  6. Individual behaviour of Baltic cod (Gadus morhua) in relation to sex and reproductive state

    DEFF Research Database (Denmark)

    Nielsen, Birgitte; Hüssy, Karin; Neuenfeldt, Stefan

    2013-01-01

    of the spawning period differs between sexes, as does the level of activity during spawning events. Not all individuals followed the general pattern; a considerable number of individuals were found to spawn in shallow water in the Arkona Basin, and juvenile fish undertook the migration without spawning......Information from data storage tags (DSTs) is conventionally used to infer movement patterns or reveal characteristics (e.g. temperature or salinity) of the environment surrounding tagged fish. Here we link data derived from DSTs with the reproductive physiology of tagged fish. Individual vertical...... activity of adult male and female Atlantic cod Gadus morhua L. in the Bornholm Basin was derived from DST measures and related to the individual histologically determined reproductive phase. Spawning migrations were identified by movements towards deeper and more saline waters. No difference was observed...

  7. Digestibility of chitin in cod, Gadus morhua, in vivo

    Science.gov (United States)

    Danulat, Eva

    1987-12-01

    Sixteen cod, Gadus morhua (L.), were individually fed a single ration of shrimps, Crangon allmanni. Four fish were killed and examined 6, 12, 24 and 48 h after the fish had been fed. Chitinase activities were measured in the extracts of stomach contents, stomach tissue, pyloric caecae, intestinal contents and intestinal tissue. The level of enzyme activity in different parts of the digestive tract was shown to be dependent on the phase of the digestive process. High concentrations of the chitin degradation product N-acetyl-D-glucosamine were determined in the stomach and in the intestinal contents. Based on the chitin concentration in the food organisms and the individual food uptake, the amount of chitin consumed by each fish could be calculated. Only up to 9% of the ingested chitin was recovered from the intestinal contents of the fish at any given time after feeding (6, 12, 24 and 48 h). In addition, only 2.4% of the chitin consumed with the food could be recovered in the collected faeces of the fish. The 4 cod killed 48 h after feeding had completely emptied their stomach. Chitin digestion in these fish was calculated to have been 90%.

  8. Transcriptome profiling reveals that feeding wild zooplankton to larval Atlantic cod (Gadus morhua) influences suites of genes involved in oxidation-reduction, mitosis, and selenium homeostasis.

    Science.gov (United States)

    Rise, Matthew L; Hall, Jennifer R; Nash, Gordon W; Xue, Xi; Booman, Marije; Katan, Tomer; Gamperl, A Kurt

    2015-11-26

    Larval nutrition and growth are key issues for wild and cultured cod. While it was shown previously that larval cod fed wild zooplankton grow faster than those fed only rotifers, the mechanisms involved in this enhanced growth are not completely understood. We used microarrays to identify larval cod transcripts that respond to feeding with small amounts of wild zooplankton (5-10 % of live prey items). The larval transcriptome was compared between 3 treatment groups [fed rotifers (RA), rotifers with protein hydrolysate (RA-PH), or rotifers with zooplankton (RA-Zoo)] at 9-10 mm length [26-30 days post-hatch (dph)] to identify a robust suite of zooplankton-responsive genes (i.e. differentially expressed between RA-Zoo and both other groups). The microarray experiment identified 147 significantly up-regulated and 156 significantly down-regulated features in RA-Zoo compared with both RA and RA-PH. Gene ontology terms overrepresented in the RA-Zoo responsive gene set included "response to selenium ion" and several related to cell division and oxidation-reduction. Ten selenoprotein-encoding genes, and 2 genes involved in thyroid hormone generation, were up-regulated in RA-Zoo compared with both other groups. Hierarchical clustering of RA-Zoo responsive genes involved in oxidation-reduction and selenium homeostasis demonstrated that only the zooplankton treatment had a considerable and consistent impact on the expression of these genes. Fourteen microarray-identified genes were selected for QPCR involving 9-13 mm larvae, and 13 of these were validated as differentially expressed between RA-Zoo and both other groups at ~9 mm. In contrast, in age-matched (34-35 dph; ~11 mm RA and RA-PH, ~13 mm RA-Zoo) and size-matched (~13 mm) older larvae, only 2 and 3 genes, respectively, showed the same direction of RA-Zoo-responsive change as in ~9 mm larvae. The modulation of genes involved in selenium binding, redox homeostasis, and thyroid hormone generation in ~9 mm RA-Zoo larvae in

  9. Infection levels and species diversity of ascaridoid nematodes in Atlantic cod, Gadus morhua, are correlated with geographic area and fish size

    DEFF Research Database (Denmark)

    Gay, M.; Bao, M.; MacKenzie, K.

    2018-01-01

    2012-2014.Prevalences for Anisakis in whole fish and in fillets in the different fishing areas varied from 16 to 100% and from 12 to 90% respectively. Abundance was also greatly influenced by the sampling area. Generalized additive model results indicate higher numbers of Anisakis in the North Sea......, even after the larger body size was accounted for. Numbers and prevalence of Anisakis were positively related to fish length or weight. The prevalence of parasites in whole fish and in fillets was also influenced by the season, with the spring displaying a peak for the prevalence in whole fish and......, at the same time, a drop for the prevalence in fillets. Whereas 46% of cod had Anisakis larvae in their fillets, the majority (39%) had parasites mainly in the ventral part of the fillet and only 12% had parasites in their dorsal part. This observation is of importance for the processing of the fish. Indeed...

  10. Behavioral responses of Atlantic cod to sea temperature changes.

    Science.gov (United States)

    Freitas, Carla; Olsen, Esben Moland; Moland, Even; Ciannelli, Lorenzo; Knutsen, Halvor

    2015-05-01

    Understanding responses of marine species to temperature variability is essential to predict impacts of future climate change in the oceans. Most ectotherms are expected to adjust their behavior to avoid extreme temperatures and minimize acute changes in body temperature. However, measuring such behavioral plasticity in the wild is challenging. Combining 4 years of telemetry-derived behavioral data on juvenile and adult (30-80 cm) Atlantic cod (Gadus morhua), and in situ ocean temperature measurements, we found a significant effect of sea temperature on cod depth use and activity level in coastal Skagerrak. During summer, cod were found in deeper waters when sea surface temperature increased. Further, this effect of temperature was stronger on larger cod. Diel vertical migration, which consists in a nighttime rise to shallow feeding habitats, was stronger among smaller cod. As surface temperature increased beyond ∼15°C, their vertical migration was limited to deeper waters. In addition to larger diel vertical migrations, smaller cod were more active and travelled larger distances compared to larger specimens. Cold temperatures during winter tended, however, to reduce the magnitude of diel vertical migrations, as well as the activity level and distance moved by those smaller individuals. Our findings suggest that future and ongoing rises in sea surface temperature may increasingly deprive cod in this region from shallow feeding areas during summer, which may be detrimental for local populations of the species.

  11. Potential Use of Atlantic Cod Trypsin in Biomedicine

    Science.gov (United States)

    Gudmundsdóttir, Ágústa; Hilmarsson, Hilmar; Stefansson, Bjarki

    2013-01-01

    Surface proteins of viruses and bacteria used for cell attachment and invasion are candidates for degradation by proteases. Trypsin from Atlantic cod (Gadus morhua) was previously demonstrated to have efficacy against influenza viruses in vitro and on skin. In this paper, cod trypsin is shown to be 3–12 times more effective in degrading large native proteins than its mesophilic analogue, bovine trypsin. This is in agreement with previous findings where cod trypsin was found to be the most active among twelve different proteases in cleaving various cytokines and pathological proteins. Furthermore, our results show that cod trypsin has high efficacy against herpes simplex virus type 1 (HSV-1) and the respiratory syncytial virus (RSV) in vitro. The results on the antipathogenic properties of cod trypsin are important because rhinovirus, RSV, and influenza are the most predominant pathogenic viruses in upper respiratory tract infections. Results from a clinical study presented in this paper show that a specific formulation containing cod trypsin was preferred for wound healing over other methods used in the study. Apparently, the high digestive ability of the cold-adapted cod trypsin towards large native proteins plays a role in its efficacy against pathogens and its positive effects on wounds. PMID:23555095

  12. Potential Use of Atlantic Cod Trypsin in Biomedicine

    Directory of Open Access Journals (Sweden)

    Ágústa Gudmundsdóttir

    2013-01-01

    Full Text Available Surface proteins of viruses and bacteria used for cell attachment and invasion are candidates for degradation by proteases. Trypsin from Atlantic cod (Gadus morhua was previously demonstrated to have efficacy against influenza viruses in vitro and on skin. In this paper, cod trypsin is shown to be 3–12 times more effective in degrading large native proteins than its mesophilic analogue, bovine trypsin. This is in agreement with previous findings where cod trypsin was found to be the most active among twelve different proteases in cleaving various cytokines and pathological proteins. Furthermore, our results show that cod trypsin has high efficacy against herpes simplex virus type 1 (HSV-1 and the respiratory syncytial virus (RSV in vitro. The results on the antipathogenic properties of cod trypsin are important because rhinovirus, RSV, and influenza are the most predominant pathogenic viruses in upper respiratory tract infections. Results from a clinical study presented in this paper show that a specific formulation containing cod trypsin was preferred for wound healing over other methods used in the study. Apparently, the high digestive ability of the cold-adapted cod trypsin towards large native proteins plays a role in its efficacy against pathogens and its positive effects on wounds.

  13. Substitution of fish oil with camelina oil and inclusion of camelina meal in diets fed to Atlantic cod (Gadus morhua) and their effects on growth, tissue lipid classes, and fatty acids.

    Science.gov (United States)

    Hixson, S M; Parrish, C C

    2014-03-01

    Developing a commercially relevant Atlantic cod aquaculture industry will require improvements in feed sustainability. Camelina oil and meal are potential replacements of fish oil and fish meal in aquaculture feeds. Camelina oil is high in 18:3ω3 (30%), with an ω3/ω6 ratio > 1. Camelina meal has a considerable crude protein level (38%), which includes significant amounts of methionine and phenylalanine. Four diets were tested; each diet was fed to triplicate tanks (3 tanks per diet) of Atlantic cod (14.4 g/fish; 70 fish per tank) for 13 wk. The diets included a fish oil/fish meal control (FO) and three diets which replaced 100% of fish oil with camelina oil: one diet contained fish meal (100CO), another solvent extracted fish meal (100COSEFM), and another had fish meal partially reduced by 15% inclusion of camelina meal (100CO15CM). Growth was measured (length and weight) and tissue samples were collected for lipid analysis (muscle, liver, brain, gut, spleen, skin, and carcass) at wk 0 (before feeding the experimental diet) and at wk 13. Cod fed camelina oil had a lower (P cod fed the FO diet (50.8 ± 10.3 g/fish). Cod fed 100CO15CM had a lower (P Cod tissues in the 100COSEFM treatment were most impacted by dietary fatty acid profile. Multivariate statistics revealed that FO and 100COSEFM tissue fatty acid profiles were 21 to 31% different, depending on tissue type. The full replacement of fish oil with camelina oil, plus solvent extracted fish meal had an overarching effect on the entire fatty acid profile of the whole animal. Fatty acid mass balance calculations indicated that cod fed 100COSEFM elongated 13% of 18:3ω3 to 20:3ω3 and oxidized the remaining 87%, whereas cod fed fish oil showed a much lower (P cod fed 100COSEFM deposited the most energy throughout the trial (60 kJ/fish; P = 0.019), mostly in the liver (90%). Excess camelina lipids were not necessarily utilized for energy, which likely impacted growth. Feeding 100% camelina oil to Atlantic cod

  14. Using otolith microstructure to analyse growth of juvenile Baltic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Mosegaard, Henrik; Hinrichsen, H.H.

    2003-01-01

    Pelagic and demersal juvenile Baltic cod Gadus morhua L. were collected on the slope and the top of Rønne bank in the Baltic Sea during 2 cruises in November and December 1998. The growth, age at settling and vertical migration pattern were studied by otolith microstructure analysis. The relation......Pelagic and demersal juvenile Baltic cod Gadus morhua L. were collected on the slope and the top of Rønne bank in the Baltic Sea during 2 cruises in November and December 1998. The growth, age at settling and vertical migration pattern were studied by otolith microstructure analysis...

  15. Puberty in male atlantic cod (Gadus morhua)

    OpenAIRE

    ALMEIDA, F. F. L. de

    2009-01-01

    Puberty is the process by which a juvenile acquires for the first time the capacity to reproduce sexually, a critical basis for the conservation of a species. In general, the biological processes constituting the first gonadal maturation and the mechanisms involved in this process are similar among vertebrates. Internal and/or external signals trigger the secretion of gonadotropin-releasing hormone (Gnrh) by neurosecretory neurons in the ventral forebrain, and Gnrh stimulates the synthesis an...

  16. Multiple ice-age refugia in Pacific cod, Gadus macrocephalus.

    Science.gov (United States)

    Canino, Michael F; Spies, Ingrid B; Cunningham, Kathryn M; Hauser, Lorenz; Grant, W Stewart

    2010-10-01

    Pleistocene ice-ages greatly influenced the historical abundances of Pacific cod, Gadus macrocephalus, in the North Pacific and its marginal seas. We surveyed genetic variation at 11 microsatellite loci and mitochondrial (mt) DNA in samples from twelve locations from the Sea of Japan to Washington State. Both microsatellite (mean H = 0.868) and mtDNA haplotype (mean h = 0.958) diversities were large and did not show any geographical trends. Genetic differentiation between samples was significantly correlated with geographical distance between samples for both microsatellites (FST = 0.028, r(2) = 0.33) and mtDNA (FST = 0.027, r(2) = 0.18). Both marker classes showed a strong genetic discontinuity between northwestern and northeastern Pacific populations that likely represents groups previously isolated during glaciations that are now in secondary contact. Significant differences appeared between samples from the Sea of Japan and Okhotsk Sea that may reflect ice-age isolations in the northwest Pacific. In the northeast Pacific, a microsatellite and mtDNA partition was detected between coastal and Georgia Basin populations. The presence of two major coastal mtDNA lineages on either side of the Pacific Ocean basin implies at least two ice-age refugia and separate postglacial population expansions facilitated by different glacial histories. Northward expansions into the Gulf of Alaska were possible 14-15 kyr ago, but deglaciation and colonization of the Georgia Basin probably occurred somewhat later. Population expansions were evident in mtDNA mismatch distributions and in Bayesian skyline plots of the three major lineages, but the start of expansions appeared to pre-date the last glacial maximum. © 2010 Blackwell Publishing Ltd.

  17. Growth, temperature and density relationships of North Sea cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Rindorf, Anna; Jensen, Henrik; Schrum, Corinna

    2008-01-01

    This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related to temper......This study presents an analysis of the relationship between ambient temperature, cod density, fishing mortality, prey fish biomass, and growth of North Sea cod (Gadus morhua) as estimated from survey catches during the period from 1983 to 2006. Growth of young cod was positively related...... to temperature; however, although temperature increased, distribution of 1-year-olds changed concurrently and no increase in length at age 1 occurred. Growth from age 1 to age 2 decreased as ambient biomass of sandeel and density of cod decreased, whereas growth of cod older than 2 years decreased...... with increasing density of cod and increased with increasing biomass of demersal fish prey. Though growth of juveniles was strongly positively correlated to ambient temperature, no indication of direct temperature limitation of growth of older North Sea cod was found....

  18. Genomic characterization of the Atlantic cod sex-locus.

    Science.gov (United States)

    Star, Bastiaan; Tørresen, Ole K; Nederbragt, Alexander J; Jakobsen, Kjetill S; Pampoulie, Christophe; Jentoft, Sissel

    2016-08-08

    A variety of sex determination mechanisms can be observed in evolutionary divergent teleosts. Sex determination is genetic in Atlantic cod (Gadus morhua), however the genomic location or size of its sex-locus is unknown. Here, we characterize the sex-locus of Atlantic cod using whole genome sequence (WGS) data of 227 wild-caught specimens. Analyzing more than 55 million polymorphic loci, we identify 166 loci that are associated with sex. These loci are located in six distinct regions on five different linkage groups (LG) in the genome. The largest of these regions, an approximately 55 Kb region on LG11, contains the majority of genotypes that segregate closely according to a XX-XY system. Genotypes in this region can be used genetically determine sex, whereas those in the other regions are inconsistently sex-linked. The identified region on LG11 and its surrounding genes have no clear sequence homology with genes or regulatory elements associated with sex-determination or differentiation in other species. The functionality of this sex-locus therefore remains unknown. The WGS strategy used here proved adequate for detecting the small regions associated with sex in this species. Our results highlight the evolutionary flexibility in genomic architecture underlying teleost sex-determination and allow practical applications to genetically sex Atlantic cod.

  19. Characterization of the fatty acyl elongase (elovl) gene family, and hepatic elovl and delta-6 fatty acyl desaturase transcript expression and fatty acid responses to diets containing camelina oil in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Xue, Xi; Feng, Charles Y; Hixson, Stefanie M; Johnstone, Kim; Anderson, Derek M; Parrish, Christopher C; Rise, Matthew L

    2014-09-01

    For aquaculture to become sustainable, there is a need to substitute fish oil [FO, rich in ω3 long chain polyunsaturated fatty acids (LC-PUFA) such as 20:5ω3 (EPA) and 22:6ω3 (DHA)] in aquafeed with plant oils such as camelina oil [CO, rich in C18 PUFA such as 18:3ω3 (ALA) and 18:2ω6 (LNA)]. The LC-PUFA are essential components in fish diets for maintaining optimal health, physiology and growth. However, most marine fish including Atlantic cod are inefficient at producing LC-PUFA from shorter chain precursors. Since elovl genes encode enzymes that play key roles in fatty acid biosynthesis, we hypothesized that they may be involved in Atlantic cod responses to diets rich in 18:3ω3 and 18:2ω6. Ten members of the cod elovl gene family were characterized at the mRNA level. RT-PCR was used to study constitutive expression of elovl transcripts in fifteen tissues. Some transcripts (e.g. elovl5) were ubiquitously expressed, while others had tissue-specific expression (e.g. elovl4a in brain and eye). Cod fed a CO-containing diet (100% CO replacement of FO and including solvent-extracted fish meal) had significantly lower weight gain, with significant up-regulation of elovl5 and fadsd6 transcripts in the liver as shown by QPCR analysis, compared with cod on a FO control diet after a 13-week trial. Multivariate statistical analyses (SIMPER and PCA) indicated that high 18:3ω3 and/or low ω3 LC-PUFA levels in the liver were associated with the up-regulation of elovl5 and fadsd6, which are involved in LC-PUFA biosynthesis in cod. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Towards sustainable fisheries of the Öresund cod (Gadus morhua) through sub-stock-specific assessment and management recommendations

    DEFF Research Database (Denmark)

    Lindegren, Martin; Waldo, Staffan; Nilsson, P. Anders

    2013-01-01

    elements. Atlantic cod (Gadus morhua) frequently occurs in spatially segregated populations, some of which exhibit fine-scaled stock structuring within current management boundaries. Here we use the locally spawning cod stock in the Sound (“Öresund”) as a case study, and perform a sub......Fisheries management traditionally relies on stock assessments assuming discrete populations within large administrational areas. However, failing to account for sub-stock structuring may result in overestimation of the stocks' true harvest potential and unsustainable exploitation of small stock......-term net benefits to the local gill-net fishery. Furthermore, our study emphasizes the need for developing sub-stock-specific management recommendations in order to ensure the maintenance of fisheries resources in general, and the persistence of sub-stock structuring in particular....

  1. Hierarchical modelling of temperature and habitat size effects on population dynamics of North Atlantic cod

    DEFF Research Database (Denmark)

    Mantzouni, Irene; Sørensen, Helle; O'Hara, Robert B.

    2010-01-01

    Understanding how temperature affects cod (Gadus morhua) ecology is important for forecasting how populations will develop as climate changes in future. The effects of spawning-season temperature and habitat size on cod recruitment dynamics have been investigated across the North Atlantic. Ricker...... and Beverton and Holt stock–recruitment (SR) models were extended by applying hierarchical methods, mixed-effects models, and Bayesian inference to incorporate the influence of these ecosystem factors on model parameters representing cod maximum reproductive rate and carrying capacity. We identified...

  2. Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size?

    OpenAIRE

    Rindorf, Anna; Andersen, Bo Sølgaard

    2008-01-01

    This study presents all investigation of the relationship between stock size of North Sea cod (Gadus morhua) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a model allowing both density-dependent changes in catchability and bias in the assessment biomass estimates. Catchability in fisheries targeting a mixed species composition either remained constant or decreased with decreasing stock size, whereas catchability in targeted cod fisheries...

  3. Environmental effects on recruitment and implications for biological reference points of Eastern Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Köster, Fritz; Vinther, Morten; MacKenzie, Brian

    2009-01-01

    The decline of the Eastern Baltic cod (Gadus morhua) stock from highest to lowest stock levels on record throughout the 1980s and early 1990s was caused by a combination of recruitment failure and increasing fishing pressure at declining stock sizes. The processes driving the reproductive success...

  4. Seasonal prevalence and intensity of follicular atresia in Baltic cod Gadus morhua callarias L

    DEFF Research Database (Denmark)

    Kraus, Gerd; Tomkiewicz, Jonna; Diekmann, R.

    2008-01-01

    In the present study, 307 ovaries of eastern Baltic cod Gadus morhua callarias sampled during the prespawning and spawning season 2000 were analysed histologically to estimate the seasonal prevalence and intensity of atresia. The number of atretic oocytes per ovary was estimated using a combination...

  5. Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod.

    Science.gov (United States)

    Bradbury, Ian R; Bowman, Sharen; Borza, Tudor; Snelgrove, Paul V R; Hutchings, Jeffrey A; Berg, Paul R; Rodríguez-Ezpeleta, Naiara; Lighten, Jackie; Ruzzante, Daniel E; Taggart, Christopher; Bentzen, Paul

    2014-01-01

    Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD) and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70%) occurring in or associated with (cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species.

  6. Exophthalmia in wild-caught cod (Gadus morhua L.): development of a secondary barotrauma effect in captivity.

    Science.gov (United States)

    Humborstad, O-B; Ferter, K; Kryvi, H; Fjelldal, P G

    2017-01-01

    Capture-based aquaculture (CBA) of Atlantic cod (Gadus morhua) has become increasingly important in recent years, and increased attention is being paid to animal welfare issues linked to these activities. Earlier studies showed that some cod develop secondary exophthalmia in captivity. This study investigated the development of secondary exophthalmia in two groups of wild-caught cod, one of which was exposed to rapid decompression causing acute barotrauma (treatment group) while the other was not (control group). Photographs and radiographs before and up to 33 days after barotrauma revealed a significant increase in overall eye protrusion caused by an accumulation of gas in the orbita in the treatment group, first observed on day 9 after decompression, while no protrusions were observed in the control group. Barotrauma was thus identified as an important trigger for the development of secondary uni- or bilateral exophthalmia of wild-caught cod. Two underlying mechanisms are suggested, where the more likely is residual swim bladder gas taking the route of least resistance, while the less likely is the exsolution of gas from the blood. Our results have implications for a wide range of contexts in which cod are rapidly brought to the surface from great depth. © 2016 John Wiley & Sons Ltd.

  7. Ribosomal RNA gene sequences confirm that protistan endoparasite of larval cod Gadus morhua is Ichthyodinium sp

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Meyer, Stefan; Overton, Julia Lynne

    2010-01-01

    An enigmatic protistan endoparasite found in eggs and larvae of cod Gadus morhua and turbot Psetta maxima was isolated from Baltic cod larvae, and DNA was extracted for sequencing of the parasite's small Subunit ribosomal RNA (SSU rRNA) gene. The endoparasite has previously been suggested...... to be related to Ichthyodinium chabelardi, a dinoflagellate-like protist that parasitizes yolk sacs of embryos and larvae of a variety of fish species. Comparison of a 1535 bp long fragment of the SSU rRNA gene of the cod endoparasite showed absolute identify with I. chabelardi, demonstrating that the 2...

  8. Evaluation of the impact of camelina oil-containing diets on the expression of genes involved in the innate anti-viral immune response in Atlantic cod (Gadus morhua).

    Science.gov (United States)

    Booman, Marije; Xu, Qingheng; Rise, Matthew L

    2014-11-01

    To improve sustainability of aquaculture, especially for carnivorous species like Atlantic cod, replacement of fish oil-based diets with vegetable oil-based diets has been studied. The use of vegetable oil in fish feeds can significantly change the fatty acid composition of fish tissues, and given the importance of fatty acids in inflammation and immunity, this change could potentially impact the immune response and health of the fish. The oilseed Camelina sativa is a promising source for this vegetable oil, because of the high oil content of its seeds (40%), a higher n-3 fatty acid content than most other oilseeds, and a high amount of γ-tocopherol. This study aims to investigate the effect of the replacement of dietary fish oil with oil from Camelina sativa on the immune response of Atlantic cod, as measured by the gene expression in spleen. Juvenile cod were fed on a fish oil-based diet (FO) or one of two diets in which camelina oil replaced 40% or 80% of fish oil (40CO and 80CO respectively) for 67 days, after which they were injected with either the viral mimic polyriboinosinic polyribocytidylic acid (pIC), or phosphate-buffered saline (PBS) as a control. Microarray analysis was used to determine the effect of the diet on the basal spleen transcriptome (pre-injection), and on the response to pIC (24 h post-injection). No marked differences in the spleen transcriptome were found between the three diets, either before or after injection with pIC. All fish, regardless of diet, showed a strong anti-viral response 24 h after pIC injection, with more than 500 genes having a significant difference of expression of 2-fold or higher compared to the PBS-injected fish for the FO, 40CO and 80CO diets. Gene Ontology annotation analysis of the three pIC-responsive gene lists indicated they were highly similar, and that the term 'immune system process' was significantly enriched in the pIC-responsive gene lists for all three diets. QPCR analysis for 5 genes with a known

  9. Cod (Gadus morhua) muscle proteome cataloging using 1D-PAGE protein separation, nano-liquid chromatography peptide fractionation, and linear trap quadrupole (LTQ) mass spectrometry.

    Science.gov (United States)

    Gebriel, Mohammed; Uleberg, Kai-Erik; Larssen, Eivind; Bjørnstad, Anne Hjelle; Sivertsvik, Morten; Møller, Simon Geir

    2010-12-08

    Because Atlantic cod (Gadus morhua) has high economic value and its protein-rich muscle tissue is a food source, an increased understanding of the effects and consequences of environmental, nutritional, biological, and industrial factors on meat quality is necessary. To gain insight into cod muscle tissue protein composition, a large-scale proteomics approach has been used. One-dimensional polyacrylamide gel electrophoresis, nanoflow liquid chromatography peptide separation, and linear trap quadrupole mass spectrometry were used to identify 4804 peptides, which retrieved 9113 cod expressed sequence tags (ESTs), which in turn were mapped to 446 unique proteins. The same data set identified 3924 proteins from the zebrafish protein database, which highlights the complementary value of the two approaches. The generated data sets will act as a foundation for studies related to physiological status assessment of cod under different environmental conditions, screening for diseases, and biomarker identification for assessment of fish quality during industrial processing and preservation.

  10. Selective haddock (Melanogrammus aeglefinus) trawling: Avoiding cod (Gadus morhua) bycatch

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Holst, René; Madsen, Niels

    2010-01-01

    a selective trawl based on the behavioral differences between haddock and cod as they enter a trawl, i.e., cod stay close to the seabed whereas haddock rise above it. The trawl's fishing line is raised similar to 60 cm above the seabed to allow cod to escape beneath the trawl while haddock are retained....... To collect the escapees, three sampling bags were attached beneath the raised fishing line. The selective haddock trawl reduced the total catch of cod by 55% during the day and 82% at night, and 99% of the marketable haddock was caught during the day and 89% at night. Cod escape rates were highly length...

  11. Do North Sea cod (Gadus morhua) fisheries maintain high catch rates at low stock size?

    DEFF Research Database (Denmark)

    Rindorf, Anna; Andersen, Bo Sølgaard

    2008-01-01

    This study presents all investigation of the relationship between stock size of North Sea cod (Gadus morhua) and catch rates in seven commercial fishing fleets. The shape of the relationship was estimated using a model allowing both density-dependent changes in catchability and bias...... in the assessment biomass estimates. Catchability in fisheries targeting a mixed species composition either remained constant or decreased with decreasing stock size, whereas catchability in targeted cod fisheries increased with decreasing stock size. However, even ill the cases where catchability increased...... of concurrent shifts in the spatial distribution of the cod stock and the cod fishery. No evidence of the former was found but there was a northern shift in the spatial distribution of both effort and the cod stock....

  12. β-naphthoflavone interferes with cyp1c1, cox2 and IL-8 gene transcription and leukotriene B4 secretion in Atlantic cod (Gadus morhua) head kidney cells during inflammation.

    Science.gov (United States)

    Holen, Elisabeth; Olsvik, Pål A

    2016-07-01

    The objective of this study was to evaluate how β-naphthoflavone interacts with lipopolysaccharide (LPS) and polyinosinic acid: polycytidylic acid (poly I: C) induced innate immune parameters as well as phase I and phase II detoxification enzymes in head kidney cells isolated from Atlantic cod. β-naphthoflavone is a pure agonist of aryl hydrocarbon receptor (AhR) while LPS and poly I: C are not. β-naphthoflavone was added to head kidney leukocytes alone or together with LPS or poly I: C and the responses were evaluated in terms of protein and gene expression. The results showed that β-naphthoflavone (25 nM), with and without LPS, significantly induced cytochrome P450 (cyp1c) transcription in cod head kidney cells. β-naphthoflavone (100 nM) in the presence of the virus mimic, poly I: C, also increased cyp1c1transcription. LPS induced cyp1c1, cyclooxygenase 2 (cox2), interleukin 1β (IL-1β), interleukin 6 (IL-6) and interleukin 8 (IL-8) transcription, genes that were not affected by the tested β-naphthoflavone concentrations alone. However, β-naphthoflavone (25 and 50 nM) strengthened LPS induced cox2 and IL-8 transcription. Cod head kidney cells exposed to β-naphthoflavone concentrations ranging from 25 to 100 nM, with and without LPS or poly I: C, expressed AhR protein. LPS or β-naphthoflavone (5-50 nM) significantly induced leukotriene B4 (LTB4) secretion compared to control. In conclusion, this study suggests that β-naphthoflavone could interfere with LPS induced immune cell signaling in cod head kidney cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Spatial and temporal trends of BFRs in Atlantic cod and polar cod in the North-East Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Bytingsvik, J.; Gaustad, H.; Pettersvik Salmer, M.; Soermo, E.G.; Munro Jenssen, B. [Norwegian Univ. of Science and Technology, Dept. of Biology, Trondheim (Norway); Baek, K.; Foereid, S. [Norwegian School of Veterinary Science, Oslo (Norway); Ruus, A. [Norwegian Insitute for Water Research, Oslo (Norway); Utne Skaare, J. [National Veterinary Institute, Oslo (Norway)

    2004-09-15

    Brominated Flame Retardants (BFRs) such as polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD) are added to materials (e.g., textiles and electronic materials) to reduce flammability. BFRs are lipophilic and resistant against degradation causing them to biomagnify in the marine food chain. Thus, due to industrial activities and surface run-off from applications and dumping sites, sediments and aquatic organism in rivers, estuaries and coastal waters close to rural areas may be particularly contaminated by these chemicals. Furthermore, because of their semi-volatile properties BFRs may also bioaccumulate in humans and wildlife at more remote locations such as the Arctic2. Their different degrees of bromination determine their actual environmental behaviour and fate. The higher brominated compounds tend to accumulate near the source whereas the lower brominated, which are more volatile, tend to end up in more remote areas such as the Arctic region. The aim of the present study was to measure BFR concentrations in cod (i.e., Atlantic cod [Gadus morhua] and polar cod [Boreogadus saida]) at different locations in Norwegian waters, ranging from the estuary of the largest river in Norway, Glomma, to the pristine Artic waters of Svalbard. Glomma has its outlet near Hvaler, outer Oslofjord, and is draining water from some of the largest rivers and lakes of the more industrialised areas of Norway. An example is its connection to Mjoesa, the largest lake in Norway, where very high levels of BFRs have been reported. Concentrations of BFRs in Atlantic cod sampled at Hvaler (58 circle 59'N, 10 circle 47'E) were therefore compared to concentrations in Atlantic cod sampled at Froan, (64 circle 10'N, 09 circle 20'E) situated in the more open waters of the Norwegian Sea off coast of Mid-Norway and polar cod from Bear Island, Svalbard (73 circle 4' N, 18 circle 3'E). A second aim was to study temporal changes in concentrations of BFRs

  14. Proceedings of the Pacific regional peer review on Pacific Cod (Gadus macrocephalus) assessment for Queen Charlotte Sound (5AB), British Columbia in 2013

    National Research Council Canada - National Science Library

    Haigh, R

    2015-01-01

    ...) Canadian Science Advisory Secretariat (CSAS) Regional Peer Review meeting on December 8, 2014 at the Pacific Biological Station in Nanaimo, British Columbia (BC). Pacific Cod (Gadus macrocephalus...

  15. Diet changes of Pacific cod (Gadus macrocephalus) in Alaska between 1980 and 1995

    OpenAIRE

    Yang, Mei-Sun

    2004-01-01

    The diet of Pacific cod (Gadus macrocephalus) in the area of Pavlof Bay, Alaska, was studied in the early 1980s by Albers and Anderson (1985). They found that the dominant prey species were forage species like pandalid shrimp, capelin (Mallotus villosus), and walleye pollock (Theragra chalcogramma). The shrimp fishery in Pavlof Bay began in 1968 and closed in 1980 because of low shrimp abundance (Ruccio and Worton1). Survey data indicate that, during the period between 1972 and 1997, the abun...

  16. Spatial and temporal distribution of Pacific cod Gadus macrocephalus juveniles in Mutsu Bay, Japan

    OpenAIRE

    Takatsu, Tetsuya; Yoshida, Yasuyuki; Kooka, Kouji; Sugimoto, Kouichi; Takahashi, Toyomi

    2001-01-01

    The spatial distributions of Pacific cod (Gadus macrocephalus) juveniles and their food organisms were examined in Mutsu Bay from April to July during 1988-1997. In April, large larvae (≤25 mm in total length (TL)) and pelagic juveniles (>25 mm TL) were widely distributed in the bay, and were concentrated at the same depths as calanoid copepodites during daylight hours. Geographical changes in cod TLs might have been due to transport by the Tsugaru Warm Current. After mid- and late May, juven...

  17. Diel variation in feeding and movement patterns of juvenile Atlantic cod at offshore wind farms

    Science.gov (United States)

    Reubens, Jan T.; De Rijcke, Maarten; Degraer, Steven; Vincx, Magda

    2014-01-01

    Atlantic cod (Gadus morhua) is a commercially important fish species suffering from overexploitation in the North-East Atlantic. In recent years, their natural environment is being intensively altered by the construction of offshore wind farms in many coastal areas. These constructions form artificial reefs influencing local biodiversity and ecosystem functioning. It has been demonstrated that Atlantic cod is present in the vicinity of these constructions. However, empirical data concerning the diel activity and feeding behaviour of Atlantic cod in the vicinity of these artificial reefs is lacking. Atlantic cod has a flexible diel activity cycle linked to spatio-temporal variations in food availability and predation risk. In this study we integrated acoustic telemetry with stomach content analysis to quantify diel activity and evaluate diel feeding patterns at a windmill artificial reef (WAR) in the Belgian part of the North Sea. Atlantic cod exhibited crepuscular movements related to feeding activity; a 12 h cycle was found and the highest catch rates and stomach fullness were recorded close to sunset and sunrise. It is suggested that the observed diel movement pattern is related to the prey species community and to predation pressure. Foraging at low ambient light levels (i.e. at dusk and dawn) probably causes a trade-off between foraging success and reducing predation pressure. Fish did not leave the area in-between feeding periods. Hence other benefits (i.e. shelter against currents and predators) besides food availability stimulate the aggregation behaviour at the WARs.

  18. Linking lipid dynamics with the reproductive cycle in Baltic cod Gadus morhua

    DEFF Research Database (Denmark)

    Røjbek, Maria; Jacobsen, Charlotte; Tomkiewicz, Jonna

    2012-01-01

    This study describes lipid composition and antioxidants of Baltic cod Gadus morhua L. during the reproductive cycle, and investigates whether they reflect its dominant prey and whether levels of fatty acids important for reproductive performance were low. Reasons for a shift in peak spawning time...... of Baltic cod from spring/early summer to midsummer since the early 1990s remain unresolved and may partly be diet related. This study demonstrated that a substantial amount of lipid was invested in cod ovarian development, and that lipid composition varied substantially with the reproductive cycle...... ovaries and decreased in late maturing and spawning fish, most likely due to their antioxidant protection activity. The fatty acid composition of cod liver reflected its clupeid prey. The ratio of 18:1n-9 to DHA was almost twice as high in sprat as in herring and indicated the ratio of sprat and herring...

  19. Saduria entomon infected with Hysterothylacium aduncum found in situ in the stomach of cod (Gadus morhua) from the Baltic Sea.

    Science.gov (United States)

    Pawlak, J; Nadolna-Ałtyn, K; Szostakowska, B; Pachur, M; Podolska, M

    2017-10-12

    The parasite fauna of cod (Gadus morhus) is well described, but the life cycles of Baltic cod parasites are known only in general terms. Invertebrates commonly found in the stomach of cod are recognized as intermediate hosts in the life cycles of nematodes or acanthocephalans. The aim of this study was to determine the source of infection of Baltic cod with parasites found in situ in invertebrates present in the cod stomach. Our results indicate that Saduria entomon is both a source of infection of Baltic cod with parasites and an intermediate host in the life cycle of Hysterothylacium aduncum in the Baltic Sea.

  20. Spatial and Temporal Patterns in the Cod Fisheries of the North Atlantic

    Directory of Open Access Journals (Sweden)

    Anne Hayden

    2015-01-01

    Full Text Available Atlantic Cod Gadus morhua has been subject to commercial exploitation since the thirteenth century. An analysis of cod fisheries over space and time reveals a pattern of serial depletion that reflects the cross-scale interaction of fish population structure, economic incentives, developments in fishing technology, and government efforts to limit access to fishing areas. Three case studies from Newfoundland and Labrador, the larger Northwest Atlantic, and the Gulf of Maine illustrate a pattern of fish population depletion followed by expansion of fishing activity that repeats at a range of scales. The meta-population structure of cod populations allows overharvesting, even when strict but broadscale controls are in place. The results argue for the reform of fisheries management to incorporate governance that more closely reflects the scale of the local components of metapopulations.

  1. Genome architecture enables local adaptation of Atlantic cod despite high connectivity

    DEFF Research Database (Denmark)

    Barth, Julia M I; Berg, Paul R; Jonsson, Per R.

    2017-01-01

    characterized by strong levels of gene flow. As one example, populations of the marine fish Atlantic cod (Gadus morhua) are highly connected due to immense dispersal capabilities but nevertheless show local adaptation in several key traits. By combining population genomic analyses based on 12K single......-nucleotide polymorphisms with larval dispersal patterns inferred using a biophysical ocean model, we show that Atlantic cod individuals residing in sheltered estuarine habitats of Scandinavian fjords mainly belong to offshore oceanic populations with considerable connectivity between these diverse ecosystems. Nevertheless...... Mb chromosomal rearrangement in fjord cod, previously proposed to comprise genes critical for the survival at low salinities. This suggests that despite considerable connectivity with offshore populations, local adaptation to fjord environments may be enabled by suppression of recombination...

  2. The genome sequence of Atlantic cod reveals a unique immune system.

    Science.gov (United States)

    Star, Bastiaan; Nederbragt, Alexander J; Jentoft, Sissel; Grimholt, Unni; Malmstrøm, Martin; Gregers, Tone F; Rounge, Trine B; Paulsen, Jonas; Solbakken, Monica H; Sharma, Animesh; Wetten, Ola F; Lanzén, Anders; Winer, Roger; Knight, James; Vogel, Jan-Hinnerk; Aken, Bronwen; Andersen, Oivind; Lagesen, Karin; Tooming-Klunderud, Ave; Edvardsen, Rolf B; Tina, Kirubakaran G; Espelund, Mari; Nepal, Chirag; Previti, Christopher; Karlsen, Bård Ove; Moum, Truls; Skage, Morten; Berg, Paul R; Gjøen, Tor; Kuhl, Heiner; Thorsen, Jim; Malde, Ketil; Reinhardt, Richard; Du, Lei; Johansen, Steinar D; Searle, Steve; Lien, Sigbjørn; Nilsen, Frank; Jonassen, Inge; Omholt, Stig W; Stenseth, Nils Chr; Jakobsen, Kjetill S

    2011-08-10

    Atlantic cod (Gadus morhua) is a large, cold-adapted teleost that sustains long-standing commercial fisheries and incipient aquaculture. Here we present the genome sequence of Atlantic cod, showing evidence for complex thermal adaptations in its haemoglobin gene cluster and an unusual immune architecture compared to other sequenced vertebrates. The genome assembly was obtained exclusively by 454 sequencing of shotgun and paired-end libraries, and automated annotation identified 22,154 genes. The major histocompatibility complex (MHC) II is a conserved feature of the adaptive immune system of jawed vertebrates, but we show that Atlantic cod has lost the genes for MHC II, CD4 and invariant chain (Ii) that are essential for the function of this pathway. Nevertheless, Atlantic cod is not exceptionally susceptible to disease under natural conditions. We find a highly expanded number of MHC I genes and a unique composition of its Toll-like receptor (TLR) families. This indicates how the Atlantic cod immune system has evolved compensatory mechanisms in both adaptive and innate immunity in the absence of MHC II. These observations affect fundamental assumptions about the evolution of the adaptive immune system and its components in vertebrates.

  3. Trans-oceanic genomic divergence of Atlantic cod ecotypes is associated with large inversions.

    Science.gov (United States)

    Berg, P R; Star, B; Pampoulie, C; Bradbury, I R; Bentzen, P; Hutchings, J A; Jentoft, S; Jakobsen, K S

    2017-12-01

    Chromosomal rearrangements such as inversions can play a crucial role in maintaining polymorphism underlying complex traits and contribute to the process of speciation. In Atlantic cod (Gadus morhua), inversions of several megabases have been identified that dominate genomic differentiation between migratory and nonmigratory ecotypes in the Northeast Atlantic. Here, we show that the same genomic regions display elevated divergence and contribute to ecotype divergence in the Northwest Atlantic as well. The occurrence of these inversions on both sides of the Atlantic Ocean reveals a common evolutionary origin, predating the >100 000-year-old trans-Atlantic separation of Atlantic cod. The long-term persistence of these inversions indicates that they are maintained by selection, possibly facilitated by coevolution of genes underlying complex traits. Our data suggest that migratory behaviour is derived from more stationary, ancestral ecotypes. Overall, we identify several large genomic regions-each containing hundreds of genes-likely involved in the maintenance of genomic divergence in Atlantic cod on both sides of the Atlantic Ocean.

  4. Effect of ocean acidification on marine fish sperm (Baltic cod: Gadus morhua)

    Science.gov (United States)

    Frommel, A. Y.; Stiebens, V.; Clemmesen, C.; Havenhand, J.

    2010-12-01

    Ocean acidification, as a consequence of increasing marine pCO2, may have severe effects on the physiology of marine organisms. However, experimental studies remain scarce, in particular concerning fish. While adults will most likely remain relatively unaffected by changes in seawater pH, early life-history stages are potentially more sensitive - particularly the critical stage of fertilization, in which sperm motility plays a central role. In this study, the effects of ocean acidification (decrease of pHT to 7.55) on sperm motility of Baltic cod, Gadus morhua, were assessed. We found no significant effect of decreased pH on sperm speed, rate of change of direction or percent motility for the population of cod analyzed. We predict that future ocean acidification will probably not pose a problem for sperm behavior, and hence fertilization success, of Baltic cod.

  5. Effect of ocean acidification on marine fish sperm (Baltic cod: Gadus morhua

    Directory of Open Access Journals (Sweden)

    J. Havenhand

    2010-12-01

    Full Text Available Ocean acidification, as a consequence of increasing marine pCO2, may have severe effects on the physiology of marine organisms. However, experimental studies remain scarce, in particular concerning fish. While adults will most likely remain relatively unaffected by changes in seawater pH, early life-history stages are potentially more sensitive – particularly the critical stage of fertilization, in which sperm motility plays a central role. In this study, the effects of ocean acidification (decrease of pHT to 7.55 on sperm motility of Baltic cod, Gadus morhua, were assessed. We found no significant effect of decreased pH on sperm speed, rate of change of direction or percent motility for the population of cod analyzed. We predict that future ocean acidification will probably not pose a problem for sperm behavior, and hence fertilization success, of Baltic cod.

  6. Quality changes during cod (Gadus morhua) desalting at different temperatures.

    Science.gov (United States)

    Oliveira, Helena; Gonçalves, Amparo; Nunes, Maria L; Vaz-Pires, Paulo; Costa, Rui

    2015-10-01

    To advise consumers and manufacturers regarding decreasing the time needed to desalt salted cod (a time-consuming process), there is a need to develop knowledge about quality changes at different desalting temperatures. The objective of this work was to evaluate the physico-chemical, microbiological and sensory quality changes and their causes during cod desalting at 5, 10 and 15 °C, using a cod/water ratio of 1:9 without water changes. The influence of slices with different thickness and different desalting times was also evaluated. Desalting promoted a decrease in the levels of total volatile basic nitrogen, thiobarbituric acid reactive substances and free amino acids nitrogen (FAA-N). The highest FAA-N values were found in 'thicker' samples desalted at 15 °C due to the higher proteolytic bacteria number observed in these samples, which activity compensated the leaching of soluble components to the desalting solution. The water uptake and the salt leaching out of the muscle found during the processes created conditions for the bacterial growth, contributing to the spoilage at 15 °C. Based on fresh odour and 'off'-flavours results, 'thicker' samples desalted at 15 °C after 72 h were close to spoilage and on microbial levels were spoiled. In order to extend the shelf life and safety of cod desalted products, desalting at temperatures above 10 °C is not advisable. © 2014 Society of Chemical Industry. © 2014 Society of Chemical Industry.

  7. Avoidance from petroleum hydrocarbons by the cod (Gadus morhua)

    OpenAIRE

    Bøhle, Bjørn

    1982-01-01

    Med norsk forord og sammendrag. In laboratory experiments cod was presented a choice situation between different concentrations of petroleum hydrocarbons, appearing as "water soluble fraction" and emulsified droplets derived from Fuel Oil No. 2. In most experiments, the fishes seemed to avoid water containing hydrocarbons, though some fishes for periods was indifferent also to considerable contaminated water. The over all results indicates that a majority of the fishes av...

  8. Relative strength of the 2010, 2011 and 2012 year classes, from nearshore surveys of demersal age 0 and 1 Atlantic cod in Newman Sound, Bonavista Bay

    National Research Council Canada - National Science Library

    Gregory, R.S; Morris, C; Newton, B; Sargent, P

    2016-01-01

    We surveyed demersal age 0 and 1 year old Atlantic cod (Gadus morhua) in the nearshore (<10 m deep) during the past 17 seasons using a seine net, to conduct a qualitative assessment of the strength of these year-classes...

  9. Effect of produced water on cod (Gadus morhua) immune responses

    Energy Technology Data Exchange (ETDEWEB)

    Hamoutene, D.; Mabrouk, G.; Samuelson, S.; Mansour, A.; Lee, K. [Fisheries and Oceans Canada, Dartmouth, NS (Canada). Maritimes Region, Ocean Sciences Division; Volkoff, H.; Parrish, C. [Memorial Univ. of Newfoundland, St. John' s, NL (Canada); Mathieu, A. [Oceans Ltd., St. John' s, NL (Canada)

    2007-07-01

    Studies have shown that produced water (PW) discharged from North Sea offshore platforms affects the biota at greater distances from operational platforms than originally presumed. According to PW dispersion simulations, dilution by at least 240 times occurs within 50-100 m, and up to 9000 times by 20 km from the discharge. In this study, the effect of PW on cod immunity was investigated by exposing fish to 0, 100 ppm (x 10,000 dilution) or 200 ppm (x 500) of PW for 76 days. Immune responses were evaluated at the end of the exposure. Fish from the 3 groups were injected with Aeromonas salmonicida lipopolysaccharides (LPS). Blood cell observation and flow cytometry were used to investigate the serum cortisol levels and gill histology along with ratios and respiratory burst (RB) responses of both circulating and head-kidney white blood cells (WBCs). The study revealed that baseline immunity and stress response were not affected by PW, other than an irritant-induced change in gill cells found in treated cod. In all groups, LPS injection resulted in a pronounced decrease in RB of head-kidney cells and an increase in serum cortisol and protein levels. However, the group exposed to 200 ppm of PW exhibited the most significant changes. LPS injection was also shown to influence WBC ratios, but further studies are needed to determine if this impact is stronger in fish exposed to PW. This study suggested an effect of PW on cod immunity after immune challenge with LPS.

  10. Eye fluke infection status in Baltic cod, Gadus morhua, after three decades and their use as ecological indicators.

    Science.gov (United States)

    Mehrdana, Foojan; Marana, Moonika H; Skov, Jakob; Bahlool, Qusay Z M; Sindberg, Diana; Mundeling, Mai; Overgaard, Bettina C; Kania, Per W; Buchmann, Kurt

    2015-09-01

    Eye flukes of the genus Diplostomum were recorded with a prevalence of 7.4% and a mean intensity of 11.9 (range 1-75) parasites per fish in eye lenses of a total of 188 Atlantic cod, Gadus morhua, sampled in the Southeastern Baltic Sea from March 2013 to February 2014. A slight decrease of infection level, among the fish with body length ranging from 30 to 89.5 cm, was found when data were compared to a corresponding survey in the 1980s. Due to imprecise species identification of eye flukes based on morphometric analyses we present, as a baseline for further studies, rDNA sequences from a subsample of 19 eye flukes based on sequencing of a part of 18S, ITS-1, 5.8S, ITS-2 and part of 28S. We discuss the use of eye fluke recordings in Baltic cod as an environmental indicator due to the dependence of the parasite's life cycle on biotic (occurrence of snail and bird hosts) and abiotic (temperature and salinity) parameters.

  11. Effect of high pressure on cod (Gadus morhua) desalting

    Science.gov (United States)

    Salvador, Ângelo C.; Saraiva, Jorge A.; Fidalgo, Liliana G.; Delgadillo, Ivonne

    2013-06-01

    The effect of high pressure on salt and water diffusion in the desalting process of cod was studied. Under pressure, up to 300 MPa, the osmotic equilibrium is reached much faster, compared to desalting at atmospheric pressure. Water (D ew) and salt (D es) effective diffusion coefficients reached a maximum at 200 MPa, increasing 500- and 160-fold, respectively, compared with desalting at atmospheric pressure. Increasing pressure up to 300 MPa causes a reduction in both effective diffusion coefficients, although they were still about 70-fold higher than at atmospheric pressure. Up to 200 MPa, a linear correlation was found between D ew and D es and pressure. However, the total diffused amounts of water and salt, when the osmotic equilibrium was reached, were lower under pressure. At atmospheric pressure cod water content increased 1.65-fold, but under pressure the increment was on average 1.25-fold, while salt content decreased to 0.51-fold the initial value at atmospheric pressure and to around 0.75-fold under pressure.

  12. Identification and characterisation of novel SNP markers in Atlantic cod: Evidence for directional selection

    Directory of Open Access Journals (Sweden)

    Fjalestad Kjersti T

    2008-02-01

    Full Text Available Abstract Background The Atlantic cod (Gadus morhua is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable management, and for marker-assisted selection and pedigree determination in aquaculture. Here, we report on the development and evaluation of a large number of Single Nucleotide Polymorphism (SNP markers from the alignment of Expressed Sequence Tag (EST sequences in Atlantic cod. We also present basic population parameters of the SNPs in samples of North-East Arctic cod and Norwegian coastal cod obtained from three different localities, and test for SNPs that may have been targeted by natural selection. Results A total of 17,056 EST sequences were used to find 724 putative SNPs, from which 318 segregating SNPs were isolated. The SNPs were tested on Atlantic cod from four different sites, comprising both North-East Arctic cod (NEAC and Norwegian coastal cod (NCC. The average heterozygosity of the SNPs was 0.25 and the average minor allele frequency was 0.18. FST values were highly variable, with the majority of SNPs displaying very little differentiation while others had FST values as high as 0.83. The FST values of 29 SNPs were found to be larger than expected under a strictly neutral model, suggesting that these loci are, or have been, influenced by natural selection. For the majority of these outlier SNPs, allele frequencies in a northern sample of NCC were intermediate between allele frequencies in a southern sample of NCC and a sample of NEAC, indicating a cline in allele frequencies similar to that found at the Pantophysin I locus. Conclusion The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.

  13. Identification and characterisation of novel SNP markers in Atlantic cod: evidence for directional selection.

    Science.gov (United States)

    Moen, Thomas; Hayes, Ben; Nilsen, Frank; Delghandi, Madjid; Fjalestad, Kjersti T; Fevolden, Svein-Erik; Berg, Paul R; Lien, Sigbjørn

    2008-02-26

    The Atlantic cod (Gadus morhua) is a groundfish of great economic value in fisheries and an emerging species in aquaculture. Genetic markers are needed to identify wild stocks in order to ensure sustainable management, and for marker-assisted selection and pedigree determination in aquaculture. Here, we report on the development and evaluation of a large number of Single Nucleotide Polymorphism (SNP) markers from the alignment of Expressed Sequence Tag (EST) sequences in Atlantic cod. We also present basic population parameters of the SNPs in samples of North-East Arctic cod and Norwegian coastal cod obtained from three different localities, and test for SNPs that may have been targeted by natural selection. A total of 17,056 EST sequences were used to find 724 putative SNPs, from which 318 segregating SNPs were isolated. The SNPs were tested on Atlantic cod from four different sites, comprising both North-East Arctic cod (NEAC) and Norwegian coastal cod (NCC). The average heterozygosity of the SNPs was 0.25 and the average minor allele frequency was 0.18. FST values were highly variable, with the majority of SNPs displaying very little differentiation while others had FST values as high as 0.83. The FST values of 29 SNPs were found to be larger than expected under a strictly neutral model, suggesting that these loci are, or have been, influenced by natural selection. For the majority of these outlier SNPs, allele frequencies in a northern sample of NCC were intermediate between allele frequencies in a southern sample of NCC and a sample of NEAC, indicating a cline in allele frequencies similar to that found at the Pantophysin I locus. The SNP markers presented here are powerful tools for future genetics work related to management and aquaculture. In particular, some SNPs exhibiting high levels of population divergence have potential to significantly enhance studies on the population structure of Atlantic cod.

  14. Host size-dependent anisakid infection in Baltic cod Gadus morhua associated with differential food preferences.

    Science.gov (United States)

    Zuo, Shaozhi; Huwer, Bastian; Bahlool, Qusay; Al-Jubury, Azmi; Daugbjerg Christensen, Nanna; Korbut, Rozalia; Kania, Per; Buchmann, Kurt

    2016-06-15

    A significant increase in the infection level of Baltic cod Gadus morhua with the anisakid nematode larvae Contracaecum osculatum and Pseudoterranova decipiens has been recorded during recent years due to the expanding local population of grey seals Halichoerus grypus, which act as final hosts for these parasites. Here, we report from an investigation of 368 cod (total length [TL] 6-49 cm; caught in ICES Subdivision 25) that the infection level of juvenile cod (TL 6-30 cm) with larvae of C. osculatum and P. decipiens is absent or very low, whereas it increases drastically in larger cod (TL 31-48 cm). A third nematode Hysterothylacium aduncum was rarely found. The study indicates that the prey animals for large cod act as transport hosts for the parasite larvae. Analyses of stomach contents of cod caught in the same area (2007-2014) showed that small benthic organisms (including polychaetes Harmothoë sarsi) are preferred food items by small cod, the isopod Saduria entomon is taken by all size classes, and sprat Sprattus sprattus are common prey items for cod larger than 30 cm. Parasitological investigations (microscopic and molecular analyses) of H. sarsi (100 specimens) and S. entomon (40 specimens) did not reveal infection in these invertebrates, but 11.6% of sprat (265 specimens examined) was shown to be infected with 1-8 C. osculatum third stage larvae per fish. Analyses of sprat stomach contents confirmed that copepods and cladocerans are the main food items of sprat. These observations suggest that the C. osculatum life cycle in the Baltic Sea includes grey seals as final hosts, sprat as the first transport host and cod as second transport host. It may be speculated that sprat obtain infection by feeding on copepods and/or cladocerans, which could serve as the first intermediate hosts. One cannot exclude the possibility that the size-dependent C. osculatum infection of cod may contribute (indirectly or directly) to the differential mortality of larger cod

  15. Spawning phenology and geography of Aleutian Islands and eastern Bering Sea Pacific cod (Gadus macrocephalus)

    Science.gov (United States)

    Neidetcher, Sandra K.; Hurst, Thomas P.; Ciannelli, Lorenzo; Logerwell, Elizabeth A.

    2014-11-01

    Pacific cod (Gadus macrocephalus) is an economically and ecologically important species in the southeastern Bering Sea and Aleutian Islands, yet little is known about the spawning dynamics of Pacific cod in these regions. To address this knowledge gap, we applied a gross anatomical maturity key for Pacific cod to describe temporal and spatial patterns of reproductive status over three winter spawning seasons: 2005, 2006, and 2007. Maturity status of female Pacific cod was assessed by fishery observers during sampling of commercial catches and used to construct maps showing spawning activity in the Bering Sea and Aleutian Islands. Most spawning activity was observed on the Bering Sea shelf and Aleutian Island plateaus between 100 and 200 m depth. Data for those days when a high percentage of spawning stage fish were observed were used to identify areas with concentrations of spawning fish. Spawning concentrations were identified north of Unimak Island, in the vicinity of the Pribilof Islands, at the shelf break near Zhemchug Canyon, and adjacent to islands in the central and western Aleutian Islands along the continental shelf. The spawning season was found to begin in the last days of February or early March and extend through early to mid-April. Variation in spawning time (averaging ~10 days between years) may have been associated with a change from warm (2005) to cold (2007) climate conditions during the study period. Our information on Pacific cod spawning patterns will help inform fishery management decisions, models of spawning and larval dispersal and the spatial structure of the stock.

  16. Factors determining variations in otolith microincrement width of demersal juvenile Baltic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Mosegaard, Henrik; Hinrichsen, H.H.

    2003-01-01

    Pelagic and demersal juvenile Baltic cod Gadus morhua L. were collected on the slope and the top of Rønne bank in the Baltic Sea during 2 cruises in November and December 1998. The objective of this study was to evaluate distinct changes in otolith increment width observed in demersal juveniles...... variable within and between individuals, in both the experimental and the field samples. The first change in increment pattern observed in the field samples was related to settling. The formation periodicity of increments within the different pattern intervals was confirmed with a growth model based...... on otolith growth rates of juvenile cod reared in the laboratory under different conditions. In this model, otolith growth rate was expressed as a function of rearing temperature and fish dry weight. Otolith growth of the field samples was calculated using ambient temperatures obtained from a 3D...

  17. Chemical surface disinfection of eggs of Baltic cod, Gadus morhua L

    DEFF Research Database (Denmark)

    Overton, J L; Bruun, Morten Sichlau; Dalsgaard, Inger

    2010-01-01

    growth was observed with increased concentrations of disinfectant (3.0 × 107–1.6 × 101 CFU mL−1). Abnormalities in newly hatched larvae were not related to disinfection. Survival of the yolk sac larvae was significantly better for eggs treated with 400 mg L−1 glutaraldehyde for 10 min at 10 and 15 dph......The effect of two disinfectants on eggs and larvae of Baltic cod, Gadus morhua, was investigated. The eggs were disinfected for 10 min using various concentrations of either glutaraldehyde (100, 200, 400, 600 and 800 mg L−1) or iodophor (10, 50, 100 and 150 mg L−1), 1–4-days post......-fertilization. Bactericidal effect of disinfection, survival to hatching, hatching success and larval abnormalities were assessed. Larval survival was recorded at 5-, 10- and 15-days post-hatch (dph). Although Baltic cod eggs have an unusually thin chorion, they could tolerate surface disinfection. A reduction in bacterial...

  18. A surgical method for implanting transmitters with sensors into the body cavity of cod (Gadus morhua L.)

    DEFF Research Database (Denmark)

    Pedersen, B.H.; Andersen, Niels Gerner

    1985-01-01

    Relatively complicated surgery is a necessity when implanting sensors internally in fish in order to measure physiological variables at specific locations. A surgical procedure from implanting transmitters with remote sensors into the body cavity of cod (Gadus morhua L.) is presented. The method...

  19. Catch-Quota Pilot Study on the Dutch commercial fishery on cod (Gadus morhua)(first period: 2010-2012

    NARCIS (Netherlands)

    Helmond, van A.T.M.; Couperus, A.S.; Warmerdam, M.J.M.; Tuinen, van D.W.

    2012-01-01

    The possibility to operate a catch-quota scheme on Dutch commercial fishing vessels was investigated in a pilot study on the commercial fishery on cod (Gadus Morhua). The project started at the end of 2010 and was fully operational, with five Dutch registered vessels, in 2011. To be able to

  20. Effect of temperature on quality-related changes in cod (Gadus morhua) during short- and long-term frozen storage

    DEFF Research Database (Denmark)

    Burgaard, Maria Garver; Jørgensen, Bo

    2010-01-01

    Cod (Gadus morhua) was stored at eight temperatures (-10 to -80 degrees C) for 1 to 18 months, after which quality indicators were measuredincluding drip loss, water holding capacity, low field NMR spin-spin relaxation, color, amount of thiobarbituric acid reactive substances, and sarcoplasmic...

  1. Effect of moderate hypoxia at three acclimation temperatures on stress responses in Atlantic cod with different haemoglobin types

    DEFF Research Database (Denmark)

    Methling, Caroline; Aluru, Neelakanteswar; Vijayan, Mathilakath M

    2010-01-01

    This study examines stress responses in Atlantic cod (Gadus morhua) when exposed to a moderate and transient reduction (35% O(2) sat.) in dissolved oxygen at a range of temperatures (5 degrees C, 10 degrees C and 15 degrees C), conditions occurring in some areas they inhabit. Given...... in a difference in stress response to hypoxia exposure. Two hsp70-isoforms (labelled a and b) were detected and they differed in expression in the gills but not in the liver of Atlantic cod. Acclimation temperature significantly affected the expression of hsp70 in the liver, and in an isoform-specific manner...... hypoxic exposure influence the organismal and cellular stress responses in Atlantic cod. We hypothesise that HbI-2 fish are more tolerant to short-term hypoxic episodes than HbI-1 fish, and this adaptation may be independent of tissue hsp70 expression....

  2. Walking the cod: an investigation into the relative robustness of cod, Gadus morhua, skeletal elements

    Directory of Open Access Journals (Sweden)

    Andrew K.G. Jones

    1999-12-01

    Full Text Available A simple experiment is described which details what happens to the bones of cod when they are walked on by a man. The pattern of fragmentation for various elements is illustrated and an index of robustness proposed for those elements in a cod skeleton most frequently recovered from archaeological sites.

  3. Mitogenome sequence variation in migratory and stationary ecotypes of North-east Atlantic cod.

    Science.gov (United States)

    Karlsen, Bård O; Emblem, Åse; Jørgensen, Tor E; Klingan, Kevin A; Nordeide, Jarle T; Moum, Truls; Johansen, Steinar D

    2014-06-01

    Sequencing of mitochondrial gene fragments from specimens representing a wide range of geographical locations has indicated limited population structuring in Atlantic cod (Gadus morhua). We recently performed whole genome analysis based on next-generation sequencing of two pooled ecotype samples representing offshore migratory and inshore stationary cod from the North-east Atlantic Ocean. Here we report molecular features and variability of the 16.7kb mitogenome component that was collected from the datasets. These sequences represented more than 25 times coverage of each individual and more than 1100 times coverage of each ecotype sample. We estimated the mitogenome to have evolved 14 times more rapidly than the nuclear genome. Among the 365 single nucleotide polymorphism (SNP) sites identified, 121 were shared between ecotypes, and 151 and 93 were private within the migratory and stationary cod, respectively. We found 323 SNPs to be located in protein coding genes, of which 29 were non-synonymous. One synonymous site in ND2 was likely to be under positive selection. FST measurements indicated weak differentiation in ND1 and ND2 between ecotypes. We conclude that the Atlantic cod mitogenome and the nuclear genome apparently evolved by distinct evolutionary constraints, and that the reproductive isolation observed from whole genome analysis was not visible in the mtDNA sequences. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Occurrence of anisakid nematodes in Atlantic cod (Gadus morhua) and Greenland cod (Gadus ogac), West Greenland

    DEFF Research Database (Denmark)

    Mouritsen, Kim N.; Hedeholm, Rasmus; Schack, Henriette B.

    2010-01-01

    larvae (L3) of three anisakid species were found, including Contracaecum osculatum (Rudolphi, 1802), Anisakis simplex (Rudolphi, 1809) and Hysterothylacium aduncum (Rudolphi, 1802). Molecular identification by PCR-RFLP indicated the presence of A. simplex s.s. and the sibling species C. osculatum B and C...

  5. Stable isotope evidence for late medieval (14th-15th C) origins of the eastern Baltic cod (Gadus morhua) fishery

    DEFF Research Database (Denmark)

    Orton, D.C.; Makowiecki, D.; de Roo, T.

    2011-01-01

    Although recent historical ecology studies have extended quantitative knowledge of eastern Baltic cod (Gadus morhua) exploitation back as far as the 16th century, the historical origin of the modern fishery remains obscure. Widespread archaeological evidence for cod consumption around the eastern...... these hypotheses we use stable carbon and nitrogen isotope analysis to determine likely catch regions of 74 cod vertebrae and cleithra from 19 Baltic archaeological sites dated from the 8th to the 16th centuries. δ13C and δ15N signatures for six possible catch regions were established using a larger sample...

  6. Temperature-mediated survival, development and hatching variation of Pacific cod Gadus macrocephalus eggs.

    Science.gov (United States)

    Bian, X; Zhang, X; Sakrai, Y; Jin, X; Gao, T; Wan, R; Yamamoto, J

    2014-01-01

    Laboratory-validated data on the survival, development and hatching responses of fertilized Pacific cod Gadus macrocephalus eggs from the northern Japan stock were determined through an incubation experiment. The optimum temperature for survival until hatching ranged from 4 to 8°C. No significant difference in development rates was found between the populations from Mutsu Bay, Japan, and western Canadian coastal waters even though the samples may belong to different G. macrocephalus stocks. Gadus macrocephalus larvae hatched asynchronously from egg batches despite incubation under the same environment during their development. Both incubation temperature and temperature-mediated hatch rank affect size and yolk reserve. These data suggest that variations in water temperatures within an ecological range markedly influence the development rates, survival and hatching of the eggs, as well as the stage at hatch larvae of G. macrocephalus. Asynchronous hatching and the production of offspring with variable sizes and yolk reserves are considered evolutionary bet-hedging strategies that enable the species to maximize their likelihood of survival in an environment with variable temperatures. © 2013 The Fisheries Society of the British Isles.

  7. Characterization of Atlantic cod spawning habitat and behavior in Icelandic coastal waters.

    Directory of Open Access Journals (Sweden)

    Timothy B Grabowski

    Full Text Available The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations off the coast of southwestern Iceland during a 2-d research cruise (15-16 April 2009. We simultaneously operated two different active hydroacoustic gear types, a split beam echosounder and a dual frequency imaging sonar (DIDSON, as well as a remotely operated underwater vehicle (ROV. A total of five fish species were identified through ROV surveys: including cusk Brosme brosme, Atlantic cod, haddock Melanogrammus aeglefinus, lemon sole Microstomus kitt, and Atlantic redfish Sebastes spp. Of the three habitats identified in the acoustic surveys, the transitional habitat between boulder/lava field and sand habitats was characterized by greater fish density and acoustic target strength compared to that of sand or boulder/lava field habitats independently. Atlantic cod were observed behaving in a manner consistent with published descriptions of spawning. Individuals were observed ascending 1-5 m into the water column from the bottom at an average vertical swimming speed of 0.20-0.25 m s(-1 and maintained an average spacing of 1.0-1.4 m between individuals. Our results suggest that cod do not choose spawning locations indiscriminately despite the fact that it is a broadcast spawning fish with planktonic eggs that are released well above the seafloor.

  8. Characterization of Atlantic cod spawning habitat and behavior in Icelandic coastal waters.

    Science.gov (United States)

    Grabowski, Timothy B; Boswell, Kevin M; McAdam, Bruce J; Wells, R J David; Marteinsdóttir, Guđrún

    2012-01-01

    The physical habitat used during spawning may potentially be an important factor affecting reproductive output of broadcast spawning marine fishes, particularly for species with complex, substrate-oriented mating systems and behaviors, such as Atlantic cod Gadus morhua. We characterized the habitat use and behavior of spawning Atlantic cod at two locations off the coast of southwestern Iceland during a 2-d research cruise (15-16 April 2009). We simultaneously operated two different active hydroacoustic gear types, a split beam echosounder and a dual frequency imaging sonar (DIDSON), as well as a remotely operated underwater vehicle (ROV). A total of five fish species were identified through ROV surveys: including cusk Brosme brosme, Atlantic cod, haddock Melanogrammus aeglefinus, lemon sole Microstomus kitt, and Atlantic redfish Sebastes spp. Of the three habitats identified in the acoustic surveys, the transitional habitat between boulder/lava field and sand habitats was characterized by greater fish density and acoustic target strength compared to that of sand or boulder/lava field habitats independently. Atlantic cod were observed behaving in a manner consistent with published descriptions of spawning. Individuals were observed ascending 1-5 m into the water column from the bottom at an average vertical swimming speed of 0.20-0.25 m s(-1) and maintained an average spacing of 1.0-1.4 m between individuals. Our results suggest that cod do not choose spawning locations indiscriminately despite the fact that it is a broadcast spawning fish with planktonic eggs that are released well above the seafloor.

  9. Daily rhythmicity of clock gene transcripts in atlantic cod fast skeletal muscle.

    Science.gov (United States)

    Lazado, Carlo C; Kumaratunga, Hiruni P S; Nagasawa, Kazue; Babiak, Igor; Giannetto, Alessia; Fernandes, Jorge M O

    2014-01-01

    The classical notion of a centralized clock that governs circadian rhythmicity has been challenged with the discovery of peripheral oscillators that enable organisms to cope with daily changes in their environment. The present study aimed to identify the molecular clock components in Atlantic cod (Gadus morhua) and to investigate their daily gene expression in fast skeletal muscle. Atlantic cod clock genes were closely related to their orthologs in teleosts and tetrapods. Synteny was conserved to varying degrees in the majority of the 18 clock genes examined. In particular, aryl hydrocarbon receptor nuclear translocator-like 2 (arntl2), RAR-related orphan receptor A (rora) and timeless (tim) displayed high degrees of conservation. Expression profiling during the early ontogenesis revealed that some transcripts were maternally transferred, namely arntl2, cryptochrome 1b and 2 (cry1b and cry2), and period 2a and 2b (per2a and per2b). Most clock genes were ubiquitously expressed in various tissues, suggesting the possible existence of multiple peripheral clock systems in Atlantic cod. In particular, they were all detected in fast skeletal muscle, with the exception of neuronal PAS (Per-Arnt-Single-minded) domain-containing protein (npas1) and rora. Rhythmicity analysis revealed 8 clock genes with daily rhythmic expression, namely arntl2, circadian locomotor output cycles kaput (clock), npas2, cry2, cry3 per2a, nuclear receptor subfamily 1, group D, member 1 (nr1d1), and nr1d2a. Transcript levels of the myogenic genes myogenic factor 5 (myf5) and muscleblind-like 1 (mbnl1) strongly correlated with clock gene expression. This is the first study to unravel the molecular components of peripheral clocks in Atlantic cod. Taken together, our data suggest that the putative clock system in fast skeletal muscle of Atlantic cod has regulatory implications on muscle physiology, particularly in the expression of genes related to myogenesis.

  10. Daily rhythmicity of clock gene transcripts in atlantic cod fast skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Carlo C Lazado

    Full Text Available The classical notion of a centralized clock that governs circadian rhythmicity has been challenged with the discovery of peripheral oscillators that enable organisms to cope with daily changes in their environment. The present study aimed to identify the molecular clock components in Atlantic cod (Gadus morhua and to investigate their daily gene expression in fast skeletal muscle. Atlantic cod clock genes were closely related to their orthologs in teleosts and tetrapods. Synteny was conserved to varying degrees in the majority of the 18 clock genes examined. In particular, aryl hydrocarbon receptor nuclear translocator-like 2 (arntl2, RAR-related orphan receptor A (rora and timeless (tim displayed high degrees of conservation. Expression profiling during the early ontogenesis revealed that some transcripts were maternally transferred, namely arntl2, cryptochrome 1b and 2 (cry1b and cry2, and period 2a and 2b (per2a and per2b. Most clock genes were ubiquitously expressed in various tissues, suggesting the possible existence of multiple peripheral clock systems in Atlantic cod. In particular, they were all detected in fast skeletal muscle, with the exception of neuronal PAS (Per-Arnt-Single-minded domain-containing protein (npas1 and rora. Rhythmicity analysis revealed 8 clock genes with daily rhythmic expression, namely arntl2, circadian locomotor output cycles kaput (clock, npas2, cry2, cry3 per2a, nuclear receptor subfamily 1, group D, member 1 (nr1d1, and nr1d2a. Transcript levels of the myogenic genes myogenic factor 5 (myf5 and muscleblind-like 1 (mbnl1 strongly correlated with clock gene expression. This is the first study to unravel the molecular components of peripheral clocks in Atlantic cod. Taken together, our data suggest that the putative clock system in fast skeletal muscle of Atlantic cod has regulatory implications on muscle physiology, particularly in the expression of genes related to myogenesis.

  11. Distribution, diet, and energetic condition of age-0 walleye pollock (Gadus chalcogrammus) and pacific cod (Gadus macrocephalus) inhabiting the Gulf of Alaska

    Science.gov (United States)

    Moss, Jamal H.; Zaleski, Marilyn F.; Heintz, Ron A.

    2016-10-01

    Walleye pollock (Gadus chalcogrammus) and Pacific cod (Gadus macrocephalus) are commercially and ecologically important species in Alaska waters. Little is known about their ecology after transitioning from larvae to free swimming fish until settlement to nursery habitats in the eastern Gulf of Alaska. Differences in the distribution, diet, body size, and energetic status between the eastern and central Gulf of Alaska were investigated during summer months to better understand regional and interspecific differences in life history and ecology. The composition of zooplankton prey in the diets of walleye pollock and Pacific cod inhabiting shelf waters was more varied relative to those inhabiting the slope and basin. Body condition and total energy content of Pacific cod was greater than walleye pollock, however total energy content increased with length at a similar rate for both species. Walleye pollock inhabiting continental slope waters had higher energy stores relative to those inhabiting the continental shelf and basin, indicating an energetic advantage for individuals remaining off the shelf during summer months or potentially the advection of fish with higher energy reserves off of the shelf. Previous studies have documented the importance of energy stores for surviving winter and future studies should focus on understanding the mechanisms influencing lipid storage and somatic growth for walleye pollock and Pacific cod inhabiting the eastern and central Gulf of Alaska.

  12. Protein genes in repetitive sequence—antifreeze glycoproteins in Atlantic cod genome

    Directory of Open Access Journals (Sweden)

    Zhuang Xuan

    2012-07-01

    Full Text Available Abstract Background Highly repetitive sequences are the bane of genome sequence assembly, and the short read lengths produced by current next generation sequencing technologies further exacerbates this obstacle. An adopted practice is to exclude repetitive sequences in genome data assembly, as the majority of repeats lack protein-coding genes. However, this could result in the exclusion of important genotypes in newly sequenced non-model species. The absence of the antifreeze glycoproteins (AFGP gene family in the recently sequenced Atlantic cod genome serves as an example. Results The Atlantic cod (Gadus morhua genome was assembled entirely from Roche 454 short reads, demonstrating the feasibility of this approach. However, a well-known major adaptive trait, the AFGP, essential for survival in frigid Arctic marine habitats was absent in the annotated genome. To assess whether this resulted from population difference, we performed Southern blot analysis of genomic DNA from multiple individuals from the North East Arctic cod population that the sequenced cod belonged, and verified that the AFGP genotype is indeed present. We searched the raw assemblies of the Atlantic cod using our G. morhua AFGP gene, and located partial AFGP coding sequences in two sequence scaffolds. We found these two scaffolds constitute a partial genomic AFGP locus through comparative sequence analyses with our newly assembled genomic AFGP locus of the related polar cod, Boreogadus saida. By examining the sequence assembly and annotation methodologies used for the Atlantic cod genome, we deduced the primary cause of the absence of the AFGP gene family from the annotated genome was the removal of all repetitive Roche 454 short reads before sequence assembly, which would exclude most of the highly repetitive AFGP coding sequences. Secondarily, the model teleost genomes used in projection annotation of the Atlantic cod genome have no antifreeze trait, perpetuating the

  13. Protein genes in repetitive sequence-antifreeze glycoproteins in Atlantic cod genome.

    Science.gov (United States)

    Zhuang, Xuan; Yang, Chun; Fevolden, Svein-Erik; Cheng, C-H Christina

    2012-07-02

    Highly repetitive sequences are the bane of genome sequence assembly, and the short read lengths produced by current next generation sequencing technologies further exacerbates this obstacle. An adopted practice is to exclude repetitive sequences in genome data assembly, as the majority of repeats lack protein-coding genes. However, this could result in the exclusion of important genotypes in newly sequenced non-model species. The absence of the antifreeze glycoproteins (AFGP) gene family in the recently sequenced Atlantic cod genome serves as an example. The Atlantic cod (Gadus morhua) genome was assembled entirely from Roche 454 short reads, demonstrating the feasibility of this approach. However, a well-known major adaptive trait, the AFGP, essential for survival in frigid Arctic marine habitats was absent in the annotated genome. To assess whether this resulted from population difference, we performed Southern blot analysis of genomic DNA from multiple individuals from the North East Arctic cod population that the sequenced cod belonged, and verified that the AFGP genotype is indeed present. We searched the raw assemblies of the Atlantic cod using our G. morhua AFGP gene, and located partial AFGP coding sequences in two sequence scaffolds. We found these two scaffolds constitute a partial genomic AFGP locus through comparative sequence analyses with our newly assembled genomic AFGP locus of the related polar cod, Boreogadus saida. By examining the sequence assembly and annotation methodologies used for the Atlantic cod genome, we deduced the primary cause of the absence of the AFGP gene family from the annotated genome was the removal of all repetitive Roche 454 short reads before sequence assembly, which would exclude most of the highly repetitive AFGP coding sequences. Secondarily, the model teleost genomes used in projection annotation of the Atlantic cod genome have no antifreeze trait, perpetuating the unawareness that the AFGP gene family is missing. We

  14. Protein genes in repetitive sequence—antifreeze glycoproteins in Atlantic cod genome

    Science.gov (United States)

    2012-01-01

    Background Highly repetitive sequences are the bane of genome sequence assembly, and the short read lengths produced by current next generation sequencing technologies further exacerbates this obstacle. An adopted practice is to exclude repetitive sequences in genome data assembly, as the majority of repeats lack protein-coding genes. However, this could result in the exclusion of important genotypes in newly sequenced non-model species. The absence of the antifreeze glycoproteins (AFGP) gene family in the recently sequenced Atlantic cod genome serves as an example. Results The Atlantic cod (Gadus morhua) genome was assembled entirely from Roche 454 short reads, demonstrating the feasibility of this approach. However, a well-known major adaptive trait, the AFGP, essential for survival in frigid Arctic marine habitats was absent in the annotated genome. To assess whether this resulted from population difference, we performed Southern blot analysis of genomic DNA from multiple individuals from the North East Arctic cod population that the sequenced cod belonged, and verified that the AFGP genotype is indeed present. We searched the raw assemblies of the Atlantic cod using our G. morhua AFGP gene, and located partial AFGP coding sequences in two sequence scaffolds. We found these two scaffolds constitute a partial genomic AFGP locus through comparative sequence analyses with our newly assembled genomic AFGP locus of the related polar cod, Boreogadus saida. By examining the sequence assembly and annotation methodologies used for the Atlantic cod genome, we deduced the primary cause of the absence of the AFGP gene family from the annotated genome was the removal of all repetitive Roche 454 short reads before sequence assembly, which would exclude most of the highly repetitive AFGP coding sequences. Secondarily, the model teleost genomes used in projection annotation of the Atlantic cod genome have no antifreeze trait, perpetuating the unawareness that the AFGP gene

  15. Effect of selenite on the uptake of methylmercury in cod (Gadus morhua)

    Energy Technology Data Exchange (ETDEWEB)

    Ringdal, O.; Julshamn, K.

    1985-09-01

    A protecting role of selenite against the toxic effects of different mercury compounds is well documented. The organ distribution and retention of inorganic mercury as well as of methylmercury seem to be influenced by a high selenium status. Mercury is characteristically present in the aquatic environment and follows the food chain. Several authors have shown a correlation between high concentrations of mercury and selenium in aquatic organisms. Virtually nothing is known about the interaction of methylmercury and selenium in feeding experiments on fish. Therefore the present study was designed to determine the possible interaction of methylmercury and selenium in different tissues of cod (Gadus morhua) by means of feeding diets supplemented with nontoxic levels of the elements.

  16. Comparison of physical and chemical characteristics of collagen from the skin of cod (Gadus macrocephaius).

    Science.gov (United States)

    Shu, Y; Ren, H; Ao, R; Qi, W C; Zhang, Z S

    2017-06-29

    Acid and pepsin-soluble collagen (ASC and PSC, respectively) were extracted from cod (Gadus macrocephaius) skin, and yields of 37.36 and 55.96% were obtained for ASC and PSC, respectively. The total yield of ASC and PSC was 93.92%, based on the lyophilized dry weight, which is higher than that obtained from other sources. Electrophoresis revealed that both ASC and PSC consisted of two different α-chains (α1 and α2), which were characterized as type I collagen. Analysis of amino acids showed that both the ASC and PSC contained imino acids (216.1 and 190.6 residues/1000 residues, respectively) and the Fourier transform infrared spectroscopy spectra of both collagens were similar with pepsin hydrolysis having no effect on their triple-helical structure. The thermal denaturation temperature of ASC and PSC, as measured by viscometry, was 26.8° and 25.6°C, respectively.

  17. Proteome analysis elucidating post-mortem changes in cod (Gadus morhua) muscle proteins.

    Science.gov (United States)

    Kjaersgård, Inger V H; Jessen, Flemming

    2003-07-02

    Proteome analysis was successfully applied to study the alterations in fish muscle proteins during ice storage. The processes occurring during post-mortem metabolism are known to lead to characteristic changes in the texture and taste of fish muscle. Endogenous proteases are anticipated to play the major role in these processes, although the exact mechanisms during fish meat tenderization have yet to be depicted. Protein changes in cod (Gadus morhua) muscle were followed during 8 days of storage. Within the partial proteome (pI 3.5-8.0, MW 13-35 kDa) significant changes were found in 11 protein spots. In nine protein spots the intensity increased, and for eight of these the increases were significant (p changes after 8 days, thereby indicating that in the fish muscle different biochemical processes are involved in the protein changes observed post-mortem.

  18. Genetic variation and local differences in Pacific cod Gadus macrocephalus around Japan.

    Science.gov (United States)

    Suda, A; Nagata, N; Sato, A; Narimatsu, Y; Nadiatul, H H; Kawata, M

    2017-01-01

    The population structure of the Pacific cod Gadus macrocephalus was examined using 15 microsatellite loci and mitochondrial DNA (ND2 region). In total, 274 individuals were sampled from 16 locations around Japan to estimate the level of genetic differentiation and effective population size (Ne ). Pairwise FST , analysis of molecular variance and Bayesian clustering analysis suggested the presence of two genetically distinct groups in waters around Japan, with a higher Ne value in the eastern group than in the western group. A possible factor that restricts gene flow between groups may be related to the water temperature differences in the south-western part of the Sea of Japan, where the Tsushima Warm Current flows around the area inhabited by the western group, which may limit migration between the west and east. © 2016 The Fisheries Society of the British Isles.

  19. The parasitic copepod Lernaeocera branchialis negatively affects cardiorespiratory function in Gadus morhua

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Seth, H.; Axelsson, M.

    2014-01-01

    The parasitic copepod Lernaeocera branchialis had a negative effect on cardiorespiratory function in Atlantic cod Gadus morhua such that it caused pronounced cardiac dysfunction with irregular rhythm and reduced stroke amplitude compared with uninfected fish. In addition, parasite infection...

  20. Harvesting Atlantic Cod under Climate Variability

    Science.gov (United States)

    Oremus, K. L.

    2016-12-01

    Previous literature links the growth of a fishery to climate variability. This study uses an age-structured bioeconomic model to compare optimal harvest in the Gulf of Maine Atlantic cod fishery under a variable climate versus a static climate. The optimal harvest path depends on the relationship between fishery growth and the interest rate, with higher interest rates dictating greater harvests now at the cost of long-term stock sustainability. Given the time horizon of a single generation of fishermen under assumptions of a static climate, the model finds that the economically optimal management strategy is to harvest the entire stock in the short term and allow the fishery to collapse. However, if the biological growth of the fishery is assumed to vary with climate conditions, such as the North Atlantic Oscillation, there will always be pulses of high growth in the stock. During some of these high-growth years, the growth of the stock and its economic yield can exceed the growth rate of the economy even under high interest rates. This implies that it is not economically optimal to exhaust the New England cod fishery if NAO is included in the biological growth function. This finding may have theoretical implications for the management of other renewable yet exhaustible resources whose growth rates are subject to climate variability.

  1. Stable isotope evidence for late medieval (14th-15th C) origins of the eastern Baltic cod (Gadus morhua) fishery

    DEFF Research Database (Denmark)

    Orton, D.C.; Makowiecki, D.; de Roo, T.

    2011-01-01

    Although recent historical ecology studies have extended quantitative knowledge of eastern Baltic cod (Gadus morhua) exploitation back as far as the 16th century, the historical origin of the modern fishery remains obscure. Widespread archaeological evidence for cod consumption around the eastern...... Baltic littoral emerges around the 13th century, three centuries before systematic documentation, but it is not clear whether this represents (1) development of a substantial eastern Baltic cod fishery, or (2) large-scale importation of preserved cod from elsewhere. To distinguish between...... of a substantial late medieval fishery. Potential human impact on cod stocks in the eastern Baltic must thus be taken into account for at least the last 600 years...

  2. The effects of WAF and CEWAF on EROD activity in juvenile Atlantic cod

    Energy Technology Data Exchange (ETDEWEB)

    Burridge, L.; Lyons, M.; Wong, D.; Li, Z.; Lee, K. [Fisheries and Oceans Canada, Ottawa, ON (Canada)

    2010-07-01

    The affects of dispersed oil and hydrocarbons on Atlantic cod were examined in this study in which water accommodated fractions (WAF) of two types of oil were generated in a wave tank or in a baffled flask. Oil droplet sizes of the two systems were comparable. Chemically enhanced water accommodated fractions (CEWAF) of combinations of two oils and two dispersants were prepared in a similar manner. Juvenile Atlantic cod (Gadus morhua) were exposed to a broad range of concentrations of either WAF or CEWAF before being transferred to clean seawater. Periodic sampling of 5 fish confirmed the liver ethoxyresorufin-O-deethylas (EROD) activity. At the end of a 4 hour exposure, EROD activity was no different from the controls, but it was much higher after 20 hours at CEWAF concentrations above 2 percent v/v regardless of oil or dispersant type. Over the next 48 hours, EROD activity declined and did not return to control or pre-treatment levels even after 72 hours. EROD in livers from cod exposed to WAF was much higher after 24 hours at concentrations of 12 percent v/v or higher, reaching a maximum of 8 picomoles/mg protein/min. After 72 hours, EROD activity in WAF-exposed livers decreased to pre-treatment levels. The study showed that a brief 4 hour exposure to WAF and CEWAF can induce EROD activity in livers of juvenile cod and that the surge in enzyme activity can continue for 24-48 hours.

  3. Evidence for and characterization of nervous necrosis virus infection in Pacific cod (Gadus macrocephalus).

    Science.gov (United States)

    Mao, Ming-Guang; Wen, Shi-Hui; Perálvarez-Marín, Alex; Li, Hua; Jiang, Jie-Lan; Jiang, Zhi-Qiang; Li, Xing; Sun, Hang; Lü, Hui-Qian

    2015-09-01

    A mortality rate higher than 90% was observed in a larva-rearing facility for Pacific cod, Gadus macrocephalus, in China. Larvae showing clinical signs of infection were collected. Initial suspicion of nervous necrosis virus (NNV) infection was confirmed by sequencing, absolute quantification real-time PCR (A-qPCR), and electron microscopy. The nucleotide sequence of RNA2 was 1,375 bases long (GenBank no. KM576685), coding for a single ORF corresponding to the capsid protein from residues 21 to 1034. Phylogenetic analysis of the capsid protein sequence showed that PCNNV belongs to the barfin flounder NNV (BFNVV) genotype. An amino acid sequence alignment revealed 39 differences between the cold- and warm-resistant viral groups, suggesting that PCNNV evolved under temperature selection. The 3-D structure of the predicted capsid protein was modeled to identify potential epitopes, and the gene was expressed in Escherichia coli, yielding a protein with a molecular mass of 55 kDa. During PCNNV outbreaks, the viral copy number was found to reach 10(7) per ng of total RNA, which could be considered the lethal copy number of NNV in cod. The gonads, eggs, fertilized eggs and asymptomatic cod fry were all positive for PCNNV, indicating viral vertical transmission as the main source of the viral load. The amount of virus in the apparent healthy fry or survivors seemed to decrease gradually with development. These results might lead to efficient diagnostic methods to help farmers select NNV-free broodfish for cod breeding.

  4. A comparative study of quality and safety of Atlantic cod (Gadus morhua) fillets during cold storage, as affected by different thawing methods of pre-rigor frozen headed and gutted fish.

    Science.gov (United States)

    Roiha, Irja Sunde; Jónsson, Ásbjörn; Backi, Christoph Josef; Lunestad, Bjørn Tore; Karlsdóttir, Magnea G

    2018-01-01

    The catch of marine whitefish is typically seasonal, whereas the land-based processing industry has a need for all-year stable supply of raw materials. This challenge can be met by applying fish frozen at sea. When using frozen fish, the methods employed for thawing may influence the safety and quality of the final product. This study aimed to investigate the applicability of novel thawing strategies in order to provide an all-year supply of high-quality and safe cod products. Comparative investigations of quality and safety factors after thawing in water, with and without air circulation, and contact thawing were performed. The parameters included water-holding capacity, thawing loss, drip loss, cooking yield, sensory evaluation and microbiological analyses (including total volatile bases nitrogen). Water thawing with air circulation provided faster thawing than water thawing without air circulation and contact thawing. For all three methods, the quality of the thawed fish was acceptable and the shelf life of the fillets during chilled storage was between 10 and 14 days post-filleting. The results show that controlled freezing of cod, followed by appropriate thawing, may provide the processing industry with an all-year delivery of raw materials, without compromising quality and safety of the final product. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  5. Comparative study of tranavirus isolates from cod (Gadus morhua) and turbot (Psetta maxima) with reference to other ranaviruses

    DEFF Research Database (Denmark)

    Ariel, Ellen; Holopainen, Riikka; Olesen, Niels Jørgen

    2010-01-01

    Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity in immun......Two iridovirus isolates recovered from cod (Gadus morhua) and turbot (Psetta maxima) in Denmark were examined in parallel with a panel of other ranaviruses including frog virus 3 (FV3), the reference strain for the genus Ranavirus. The isolates were assessed according to their reactivity...... to rainbow trout under experimental challenge conditions was investigated. The viruses were serologically and genetically closely related to highly pathogenic ranaviruses such as European catfish iridovirus (ECV), European sheatfish iridovirus (ESV) and epizootic haematopoietic necrosis virus (EHNV...

  6. The Impact of Egg Ozonation on Hatching Success, Larval Growth, and Survival of Atlantic Cod, Atlantic Salmon, and Rainbow Trout.

    Science.gov (United States)

    Fry, Jessica; Casanova, Pérez Juan; Hamoutene, Dounia; Lush, Lynn; Walsh, Andy; Couturier, Cyr

    2015-03-01

    The direct exposure of fish eggs to ozonated water has generated interest as a means of ensuring pathogen-free eggs without the use of harsh chemicals. However, there are numerous knowledge gaps, including safe contact times, exposure levels, and potential long-term effects on aquaculture species in both freshwater and seawater. The effect of different ozone (O3) doses (0.5-1.0, 1.5-2.0, and 2.5-3.0 mg of O3/L for 90 s) on recently fertilized eggs of Atlantic Cod Gadus morhua and eyed eggs of Atlantic Salmon Salmo salar and Rainbow Trout Oncorhynchus mykiss was evaluated in comparison with the effects of two commercial disinfectants: Perosan (0.004 mg/L) and Ovadine (100 mg/L). The impact of ozone application was evaluated based on hatching success, larval nucleic acid concentration, larval growth, and survival. Overall, results indicated that ozonation of Atlantic Cod eggs at a dose less than 3.0 mg/L for 90 s produced no negative effect on the larvae up to 30 d posthatch. Furthermore, ozonation of Atlantic Salmon and Rainbow Trout eggs generated no negative effect on the larvae, based on monitoring until 85% yolk sac re-absorption (16 d posthatch).

  7. Improved rotatory-flow technique applied to cod (Gadus morrhua L. )

    Energy Technology Data Exchange (ETDEWEB)

    Lindahl, P.E.; Oloesson, S.; Schwanbom, E.

    1976-01-01

    An improved version of rotatory-flow apparatus is described, allowing tests of fitness with fish of different size at constant temperature. Cod (Gadus morrhua, L.) was used as experimental animal, and its treatment and behavior during different phases of the test are described in some detail. Each test results in determination of the ''critical rev min/sup -1/'' at which the fish is just brought to rotate with the water. The mean of a series of 10 critical rev min/sup -1/ with the same fish, multiplied by the interior circumference of the rotational tube used, gives the ''critical peripheral velocity'' of the specimen. Critical peripheral velocities of a sample of fish, plotted against the standard length of the fish, arrange themselves along a straight line which intersects the vertical axis near the origin. Divided by the corresponding standard lengths the critical peripheral velocities give ''reaction quotients,'' the mean of which describe the reaction of the whole sample of fish. Optimal experimental conditions have been found by investigating the effects of systematic variation in streaming velocity, relationship between rotational tube diameter and fin-breadth, temperature and effects of repetition of test-series on successive days etc. on the results of testing. Changes in temperature of 3 to 6C induced significant changes in mean reaction quotients only when the upper critical temperature of cod was reached.

  8. Effects of seismic shooting on local abundance and catch rates of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus)

    OpenAIRE

    Engås, Arill; Løkkeborg, Svein; Ona, Egil; Soldal, Aud Vold

    1996-01-01

    To determine whether seismic exploration affected abundance or catch rates of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus), acoustic mapping and fishing trials with trawls and longlines were conducted in the central Barents Sea 7 days before, 5 days during, and 5 days after seismic shooting with air guns. Seismic shooting severely affected fish distribution, local abundance, and catch rates in the entire investigation area of 40 ´ 40 nautical miles.Trawl catches of co...

  9. Ontogenetic patterns and temperature-dependent growth rates in early life stages of Pacific cod (Gadus macrocephalus)

    OpenAIRE

    Hurst, Thomas P.; Benjamin J. Laurel; Ciannelli, Lorenzo

    2010-01-01

    Pacific cod (Gadus macrocephalus) is an important component of fisheries and food webs in the North Pacific Ocean and Bering Sea. However, vital rates of early life stages of this species have yet to be described in detail. We determined the thermal sensitivity of growth rates of embryos, preflexion and postflexion larvae, and postsettlement juveniles. Growth rates (length and mass) at each ontogenetic stage were measured in three replicate tanks at four to five temperatures. Nonl...

  10. Stable isotope evidence for late medieval (14th-15th C origins of the eastern Baltic cod (Gadus morhua fishery.

    Directory of Open Access Journals (Sweden)

    David C Orton

    Full Text Available Although recent historical ecology studies have extended quantitative knowledge of eastern Baltic cod (Gadus morhua exploitation back as far as the 16th century, the historical origin of the modern fishery remains obscure. Widespread archaeological evidence for cod consumption around the eastern Baltic littoral emerges around the 13th century, three centuries before systematic documentation, but it is not clear whether this represents (1 development of a substantial eastern Baltic cod fishery, or (2 large-scale importation of preserved cod from elsewhere. To distinguish between these hypotheses we use stable carbon and nitrogen isotope analysis to determine likely catch regions of 74 cod vertebrae and cleithra from 19 Baltic archaeological sites dated from the 8th to the 16th centuries. δ(13C and δ(15N signatures for six possible catch regions were established using a larger sample of archaeological cod cranial bones (n = 249. The data strongly support the second hypothesis, revealing widespread importation of cod during the 13th to 14th centuries, most of it probably from Arctic Norway. By the 15th century, however, eastern Baltic cod dominate within our sample, indicating the development of a substantial late medieval fishery. Potential human impact on cod stocks in the eastern Baltic must thus be taken into account for at least the last 600 years.

  11. Ultrapure LPS induces inflammatory and antibacterial responses attenuated in vitro by exogenous sera in Atlantic cod and Atlantic salmon.

    Science.gov (United States)

    Seppola, Marit; Mikkelsen, Helene; Johansen, Audny; Steiro, Kari; Myrnes, Bjørnar; Nilsen, Inge W

    2015-05-01

    Phagocyte recognition of lipopolysaccharide (LPS) is an early key event for triggering the host innate immune response necessary for clearance of invading bacteria. The ability of fishes to recognise LPS has been questioned as contradictory results have been presented. We show here that monocyte/macrophage cultures from Atlantic cod (Gadus morhua) and Atlantic salmon (Salmo salar) respond with an increased expression of inflammatory and antibacterial genes to both crude and ultrapure Escherichia coli LPS. Crude LPS produces higher induction than the ultrapure LPS type in both species in vitro as well as in vivo in cod injected with LPS. Crude LPS gave, in contrast to ultrapure LPS, an additional weak up-regulation of antiviral genes in salmon macrophages, most likely because of contaminants in the LPS preparation. Increased levels of chicken (c)-type lysozyme transcripts and enzyme activity were measured in salmon macrophages following ultrapure LPS stimulation demonstrating not only increased transcription but also translation. Simultaneous use and even pre-treatment with bovine sera suppressed the LPS-induced expression thereby reflecting the presence of transcription inhibitory components in sera. Together, these findings show that both cod and salmon recognise LPS per se and that the observed induction is highly dependent on the absence of sera. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. An improved genome assembly uncovers prolific tandem repeats in Atlantic cod.

    Science.gov (United States)

    Tørresen, Ole K; Star, Bastiaan; Jentoft, Sissel; Reinar, William B; Grove, Harald; Miller, Jason R; Walenz, Brian P; Knight, James; Ekholm, Jenny M; Peluso, Paul; Edvardsen, Rolf B; Tooming-Klunderud, Ave; Skage, Morten; Lien, Sigbjørn; Jakobsen, Kjetill S; Nederbragt, Alexander J

    2017-01-18

    The first Atlantic cod (Gadus morhua) genome assembly published in 2011 was one of the early genome assemblies exclusively based on high-throughput 454 pyrosequencing. Since then, rapid advances in sequencing technologies have led to a multitude of assemblies generated for complex genomes, although many of these are of a fragmented nature with a significant fraction of bases in gaps. The development of long-read sequencing and improved software now enable the generation of more contiguous genome assemblies. By combining data from Illumina, 454 and the longer PacBio sequencing technologies, as well as integrating the results of multiple assembly programs, we have created a substantially improved version of the Atlantic cod genome assembly. The sequence contiguity of this assembly is increased fifty-fold and the proportion of gap-bases has been reduced fifteen-fold. Compared to other vertebrates, the assembly contains an unusual high density of tandem repeats (TRs). Indeed, retrospective analyses reveal that gaps in the first genome assembly were largely associated with these TRs. We show that 21% of the TRs across the assembly, 19% in the promoter regions and 12% in the coding sequences are heterozygous in the sequenced individual. The inclusion of PacBio reads combined with the use of multiple assembly programs drastically improved the Atlantic cod genome assembly by successfully resolving long TRs. The high frequency of heterozygous TRs within or in the vicinity of genes in the genome indicate a considerable standing genomic variation in Atlantic cod populations, which is likely of evolutionary importance.

  13. Francisella noatunensis subsp. noatunensis invades, survives and replicates in Atlantic cod cells.

    Science.gov (United States)

    Bakkemo, Kathrine R; Mikkelsen, Helene; Johansen, Audny; Robertsen, Børre; Seppola, Marit

    2016-09-26

    Systemic infection caused by the facultative intracellular bacterium Francisella noatunensis subsp. noatunensis remains a disease threat to Atlantic cod Gadus morhua L. Future prophylactics could benefit from better knowledge on how the bacterium invades, survives and establishes infection in its host cells. Here, facilitated by the use of a gentamicin protection assay, this was studied in primary monocyte/macrophage cultures and an epithelial-like cell line derived from Atlantic cod larvae (ACL cells). The results showed that F. noatunensis subsp. noatunensis is able to invade primary monocyte/macrophages, and that the actin-polymerisation inhibitor cytochalasin D blocked internalisation, demonstrating that the invasion is mediated through phagocytosis. Interferon gamma (IFNγ) treatment of cod macrophages prior to infection enhanced bacterial invasion, potentially by stimulating macrophage activation in an early step in host defence against F. noatunensis subsp. noatunensis infections. We measured a rapid drop of the initial high levels of internalised bacteria in macrophages, indicating the presence and action of a cellular immune defence mechanism before intracellular bacterial replication took place. Low levels of bacterial internalisation and replication were detected in the epithelial-like ACL cells. The capacity of F. noatunensis subsp. noatunensis to enter, survive and even replicate within an epithelial cell line may play an important role in its ability to infect live fish and transverse epithelial barriers to reach the bacterium's main target cells-the macrophage.

  14. Effect of petroleum hydrocarbons on Atlantic cod, Gadusmorhua, following chronic exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kiceniuk, J.W. (Dept. of Fisheries and Oceans, St. John' s, NF (Canada)); Khan, R.A. (Memorial Univ. of Newfoundland, St. John' s, NF (Canada))

    1987-01-01

    Experiments were conducted to ascertain the effects of crude oils at low concentrations on Atlantic cod (Gadus morhua) following long-term exposure (3-21 weeks) in a flow-through seawater system. Control and oil-treated fish were fed to satiation. Effects were assessed by comparing condition factor, organ indices, and hematological values with those of corresponding control animals. No mortality occurred but food consumption was significantly reduced in oil-treated cod, especially during summer-autumn. Condition factor and somatic indices of some organs were lower in oil-treated fish. Gall bladders were enlarged in oil-treated fish. Effects of oil exposure were less pronounced during winter, as food intake in both groups of fish was reduced considerably. The rate of gametogenesis was slower in male cod exposed to oil fractions in summer-autumn whereas spermeation was delayed in fish treated in winter-spring. These studies provide evidence that feeding, growth, and reproduction in male cod are biologically important variables that are affected following chronic exposure to petroleum. 22 refs., 4 tabs.

  15. Oxygen limitation of thermal tolerance in cod, Gadus morhua L., studied by magnetic resonance imaging and on-line venous oxygen monitoring.

    Science.gov (United States)

    Lannig, Gisela; Bock, Christian; Sartoris, Franz J; Pörtner, Hans O

    2004-10-01

    The hypothesis of an oxygen-limited thermal tolerance due to restrictions in cardiovascular performance at extreme temperatures was tested in Atlantic cod, Gadus morhua (North Sea). Heart rate, changes in arterial and venous blood flow, and venous oxygen tensions were determined during an acute temperature change to define pejus ("getting worse") temperatures that border the thermal optimum range. An exponential increase in heart rate occurred between 2 and 16 degrees C (Q(10) = 2.38 +/- 0.35). Thermal sensitivity was reduced beyond 16 degrees C when cardiac arrhythmia became visible. Flow-weighted magnetic resonance imaging (MRI) measurements of temperature-dependent blood flow revealed no exponential but a hyperbolic increase of blood flow with a moderate linear increase at temperatures >4 degrees C. Therefore, temperature-dependent heart rate increments are not mirrored by similar increments in blood flow. Venous Po(2) (Pv(O(2))), which reflects the quality of oxygen supply to the heart of cod (no coronary circulation present), followed an inverse U-shaped curve with highest Pv(O(2)) levels at 5.0 +/- 0.2 degrees C. Thermal limitation of circulatory performance in cod set in below 2 degrees C and beyond 7 degrees C, respectively, characterized by decreased Pv(O(2)). Further warming led to a sharp drop in Pv(O(2)) beyond 16.1 +/- 1.2 degrees C in accordance with the onset of cardiac arrhythmia and, likely, the critical temperature. In conclusion, progressive cooling or warming brings cod from a temperature range of optimum cardiac performance into a pejus range, when aerobic scope falls before critical temperatures are reached. These patterns might cause a shift in the geographical distribution of cod with global warming.

  16. Stable oxygen isotope reconstruction of ambient temperature during the collapse of a cod (Gadus morhua) fishery.

    Science.gov (United States)

    Jones, J Brin; Campana, Steven E

    2009-09-01

    Changing environmental conditions set against a backdrop of high exploitation can result in severe consequences for commercially harvested stocks. The collapse of the Eastern Scotian Shelf cod (Gadus morhua L.) off eastern Canada was primarily due to overexploitation but may have been exacerbated by a widespread temperature decline. Recent studies have called for accurate determination of ambient temperature (the actual temperature exposure history of the fish) before discarding environmental conditions as a factor in the collapse. We used the stable oxygen isotope composition of otoliths (delta18O(oto)) to reconstruct the ambient temperature history of Eastern Scotian Shelf cod from 1970 to 2000 in order to determine whether the stock experienced the temperature decline or shifted their distribution to avoid it. To correct delta18O(oto) for seawater isotope content (deltaO(w)), we generated a new meta-equation for the relationship between delta18O(w) (per mil) and salinity (S, in psu) on the Eastern Scotian Shelf: delta18O(w) = 0.539 x S - 18.790. The ambient temperature series revealed that the large-scale geographic distribution of mature cod remained constant through the cooling period, although their ambient temperature was cooler than expected in warmer periods and warmer than expected in cooler periods, indicating small-scale thermoregulatory movement. Although the mean hydrographic temperature was 4 degrees C, mature cod usually inhabited the coldest available waters (mean ambient temperature = 3 degrees C), while the juveniles usually inhabited warmer waters (mean ambient temperature = 5.5 degrees C). Length-at-age was significantly related to ambient temperature, especially in the early years of growth, and therefore declining ambient temperatures were at least partially responsible for declines in asymptotic length (up to age 8 yr). The most active thermoregulatory movement occurred during a moderate warming period; therefore extreme warming events (such

  17. Envelope surface ultrastructure and specific gravity of artificially fertilized Pacific cod Gadus macrocephalus eggs.

    Science.gov (United States)

    Bian, X; Zhang, X; Sakurai, Y; Jin, X; Gao, T; Wan, R; Yamamoto, J

    2014-02-01

    The envelope surface ultrastructure and specific gravity of artificially fertilized eggs of the Pacific cod Gadus macrocephalus were examined. The unfertilized, demersal and slightly adhesive eggs of G. macrocephalus were almost spherical and had no oil globules. Wrinkled envelope surface with elaborated hexagonal reticulated patterns and type I micropyle were observed under a scanning electron microscope. The adhesiveness of the eggs was lost at the blastodermal-cap stage after fertilization. The micropylar canal was sealed by secretion of the perivitelline fluid, and the entire surface became rough. Numerous bacilli were deposited at the micropyle and the outer envelope surface at the late germ-ring stage and at the embryo five-eighths around the yolk stage. The micropyle was completely deformed at the embryo seven-eighths around the yolk stage. The specific gravity of the fertilized G. macrocephalus eggs ranged from c. 1·0316 to 1·0454. These values, however, sharply decreased towards the end stages of egg development to produce pelagic larvae. The ultrastructural changes in the micropyle and envelope surface of the G. macrocephalus eggs protected the embryo from microorganism infections and mechanical stress during the long incubation period. The adhesiveness and specific gravity of the eggs influenced their dispersion potential. © 2014 The Fisheries Society of the British Isles.

  18. A novel beta-defensin antimicrobial peptide in Atlantic cod with stimulatory effect on phagocytic activity.

    Directory of Open Access Journals (Sweden)

    Jareeporn Ruangsri

    Full Text Available A novel defensin antimicrobial peptide gene was identified in Atlantic cod, Gadus morhua. This three exon/two intron defensin gene codes for a peptide precursor consisting of two domains: a signal peptide of 26 amino acids and a mature peptide of 40 residues. The mature cod defensin has six conserved cysteine residues that form 1-5, 2-4 and 3-6 disulphide bridges. This pattern is typical of beta-defensins and this gene was therefore named cod beta-defensin (defb. The tertiary structure of Defb exhibits an α/β fold with one α helix and β1β2β3 sheets. RT-PCR analysis indicated that defb transcripts were present mainly in the swim bladder and peritoneum wall but could also be detected at moderate to low levels in skin, head- and excretory kidneys. In situ hybridisation revealed that defb was specifically expressed by cells located in the swim bladder submucosa and the oocytes. During embryonic development, defb gene transcripts were detectable from the golden eye stage onwards and their expression was restricted to the swim bladder and retina. Defb was differentially expressed in several tissues following antigenic challenge with Vibrio anguillarum, being up-regulated up to 25-fold in head kidney. Recombinant Defb displayed antibacterial activity, with a minimal inhibitory concentration of 0.4-0.8 µM and 25-50 µM against the Gram-(+ bacteria Planococcus citreus and Micrococcus luteus, respectively. In addition, Defb stimulated phagocytic activity of cod head kidney leucocytes in vitro. These findings imply that beta-defensins may play an important role in the innate immune response of Atlantic cod.

  19. A Novel Beta-Defensin Antimicrobial Peptide in Atlantic Cod with Stimulatory Effect on Phagocytic Activity

    Science.gov (United States)

    Ruangsri, Jareeporn; Kitani, Yoichiro; Kiron, Viswanath; Lokesh, Jep; Brinchmann, Monica F.; Karlsen, Bård Ove; Fernandes, Jorge M. O.

    2013-01-01

    A novel defensin antimicrobial peptide gene was identified in Atlantic cod, Gadus morhua. This three exon/two intron defensin gene codes for a peptide precursor consisting of two domains: a signal peptide of 26 amino acids and a mature peptide of 40 residues. The mature cod defensin has six conserved cysteine residues that form 1–5, 2–4 and 3–6 disulphide bridges. This pattern is typical of beta-defensins and this gene was therefore named cod beta-defensin (defb). The tertiary structure of Defb exhibits an α/β fold with one α helix and β1β2β3 sheets. RT-PCR analysis indicated that defb transcripts were present mainly in the swim bladder and peritoneum wall but could also be detected at moderate to low levels in skin, head- and excretory kidneys. In situ hybridisation revealed that defb was specifically expressed by cells located in the swim bladder submucosa and the oocytes. During embryonic development, defb gene transcripts were detectable from the golden eye stage onwards and their expression was restricted to the swim bladder and retina. Defb was differentially expressed in several tissues following antigenic challenge with Vibrio anguillarum, being up-regulated up to 25-fold in head kidney. Recombinant Defb displayed antibacterial activity, with a minimal inhibitory concentration of 0.4–0.8 µM and 25–50 µM against the Gram-(+) bacteria Planococcus citreus and Micrococcus luteus, respectively. In addition, Defb stimulated phagocytic activity of cod head kidney leucocytes in vitro. These findings imply that beta-defensins may play an important role in the innate immune response of Atlantic cod. PMID:23638029

  20. Long distance linkage disequilibrium and limited hybridization suggest cryptic speciation in atlantic cod.

    Directory of Open Access Journals (Sweden)

    Ian R Bradbury

    Full Text Available Hybrid zones provide unprecedented opportunity for the study of the evolution of reproductive isolation, and the extent of hybridization across individuals and genomes can illuminate the degree of isolation. We examine patterns of interchromosomal linkage disequilibrium (ILD and the presence of hybridization in Atlantic cod, Gadus morhua, in previously identified hybrid zones in the North Atlantic. Here, previously identified clinal loci were mapped to the cod genome with most (∼70% occurring in or associated with (<5 kb coding regions representing a diverse array of possible functions and pathways. Despite the observation that clinal loci were distributed across three linkage groups, elevated ILD was observed among all groups of clinal loci and strongest in comparisons involving a region of low recombination along linkage group 7. Evidence of ILD supports a hypothesis of divergence hitchhiking transitioning to genome hitchhiking consistent with reproductive isolation. This hypothesis is supported by Bayesian characterization of hybrid classes present and we find evidence of common F1 hybrids in several regions consistent with frequent interbreeding, yet little evidence of F2 or backcrossed individuals. This work suggests that significant barriers to hybridization and introgression exist among these co-occurring groups of cod either through strong selection against hybrid individuals, or genetic incompatibility and intrinsic barriers to hybridization. In either case, the presence of strong clinal trends, and little gene flow despite extensive hybridization supports a hypothesis of reproductive isolation and cryptic speciation in Atlantic cod. Further work is required to test the degree and nature of reproductive isolation in this species.

  1. Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing

    DEFF Research Database (Denmark)

    Sparrevohn, Claus Reedtz; Storr-Paulsen, Marie

    2012-01-01

    Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing. – ICES Journal of Marine Science, 69: 323–330.Marine recreational fishing is a popular outdoor activity in Denmark, practised by both anglers and passive gear fishers...... with the mandatory Danish fishing licence. The second survey was designed to identify those who fish without a licence. It was estimated that 1231 t of cod were harvested in 2009, corresponding to 4.8% of the entire Danish cod yield (recreational harvest + commercial landings). Area differences were found, and...... to 19% of the entire Danish eel yield. The inclusion of the harvest taken by fishers without a valid licence was important and added almost 20% to the estimated harvest....

  2. EVOLUTION OF ATLANTIC AND PACIFIC COD: LOSS OF GENETIC VARIATION AND GENE EXPRESSION IN PACIFIC COD.

    Science.gov (United States)

    Grant, W Stewart; Ståhl, Gunnar

    1988-01-01

    An allozyme investigation of 41 protein-coding loci in two morphologically similar fishes, Atlantic and Pacific cod, indicates that Pacific cod experienced a severe population bottleneck that led to the loss of gene diversity and gene expression. Pacific cod possesses a significantly lesser amount of gene diversity (H = 0.032) than Atlantic cod (H = 0.125) and lacks gene expression for Me-3. Allele-frequency distributions differ between species as predicted by neutral theory: Atlantic cod has a U-shaped distribution, which is expected for populations in drift-mutation equilibrium, whereas Pacific cod has a J-shaped distribution with an excess of low-frequency alleles. This excess may be explained by the appearance of new alleles through mutation which have not yet reached intermediate frequencies through drift. The population bottleneck in Pacific cod was most likely associated with founder populations that dispersed into the Pacific Ocean after the Bering Strait opened. Under the molecular-clock hypothesis a Nei genetic distance of 0.415 (based on 41 loci) suggests that Pacific cod dispersed into the Pacific Ocean soon after the Bering Strait opened in the mid-Pliocene, 3.0 to 3.5 million years ago. © 1988 The Society for the Study of Evolution.

  3. Transcriptomic analysis and biomarkers (Rag1 and Igμ) for probing the immune system development in Pacific cod, Gadus macrocephalus.

    Science.gov (United States)

    Mao, Ming-Guang; Li, Xing; Perálvarez-Marín, Alejandro; Jiang, Jie-Lan; Jiang, Zhi-Qiang; Wen, Shi-Hui; Lü, Hui-Qian

    2015-06-01

    Mortality (>90%) is a big concern in larval rearing facilities of Pacific cod, Gadus macrocephalus, limiting its culture presently still in the experimental stages. Understanding the immune system development of G. macrocephalus is crucial to optimize the aquaculture of this species, to improve the use of economic resources and to avoid abuse of antibiotics. For the transcriptome analysis, using an Illumina sequencing platform, 61,775,698 raw reads were acquired. After a de novo assembly, 77,561 unigenes were obtained. We have classified functionally these transcripts by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). 27 genes mainly related to hematopoietic or lymphoid organ development and somatic diversification of immune receptors have been reported for the first time in Pacific cod, and 14 Ig heavy chain (μ chain) locuses were assembled using Trinity. Based on our previous achievement, we have chosen Rag1 and Igμ as immune system development biomarkers. Full length cDNA of Rag1 and Igμ as biomarkers were obtained respectively using RACE PCR. Concerning Rag1, the deduced amino acid of Rag1 and protein immunodetection revealed a Rag1 isoform of 69 kDa, significantly different from other fish orthologs, such as Oncorhynchus mykiss (121 kDa). Phylogenetic analysis reveals a unique immune system for the Gadus genre, not exclusive for Atlantic cod, among vertebrates. Meanwhile, full length cDNA of Igμ included an ORF of 1710 bp and the deduced amino acid was composed of a leader peptide, a variable domain, CH1, CH2, Hinge, CH3, CH4 and C-terminus, which was in accordance with most teleost. Absolute quantification PCR revealed that significant expression of Rag1 appeared earlier than Igμ, 61 and 95 dph compared to 95 dph, respectively. Here we report the first transcriptomic analysis of G. macrocephalus as the starting point for genetic research on immune system development towards improving the Pacific cod aquaculture. Copyright © 2015

  4. Third-stage nematode larvae of Contracaecum osculatum from Baltic cod (Gadus morhua) elicit eosinophilic granulomatous reactions when penetrating the stomach mucosa of pigs.

    Science.gov (United States)

    Strøm, S B; Haarder, S; Korbut, R; Mejer, H; Thamsborg, S M; Kania, P W; Buchmann, K

    2015-03-01

    Third-stage larvae of the anisakid nematode Contracaecum osculatum were recovered from livers of Atlantic cod (Gadus morhua) caught in the Baltic Sea (June 2014) and used for experimental infection of two pigs (one male and one female). Each pig received 215 larvae by oral infection (feeding with minced cod liver containing live nematode larvae). Pigs were euthanized after 5 days, necropsied, and subjected to parasitological investigation. A total of 12 larvae were found penetrating the mucosa of the ventricle (7 in the female pig and 5 in the male pig) eliciting a granulomatous reaction at the penetration site. Four non-attached larvae were found in the female pig stomach and one in the male pig. Petechial bleeding was observed at several locations in the ventricular mucosa where larvae were located. Histological examination of the stomach mucosa revealed a massive cellular infiltration (giant cells, lymphocytes, macrophages, granulocytes, and fibroblast like cells) around the penetrating larva. Mononuclear and polymorphonuclear cells containing eosinophilic granulae were particularly prominent in the granulomas. Reactions correspond to reactions in pigs following experimental infection with the human pathogenic anisakid larvae Anisakis sp. and Pseudoterranova sp. which suggests that C. osculatum might have a zoonotic potential as well.

  5. Genetic differentiation of Pacific cod Gadus macrocephalus in the Sea of Okhotsk and in the Bering Sea.

    Science.gov (United States)

    Smirnova, M A; Orlova, S Yu; Mugue, N S; Mukhametov, I N; Smirnov, A A; Orlov, A M

    2015-01-01

    Genetic differentiation of the Pacific cod Gadus macrocephalus was studied. Samples from six regions of the Sea of Okhotsk and the Bering Sea were analyzed with two mtDNA genetic markers-gene of cytochrome 1 and the control region (D-loop). Comparative analysis showed significant genetic differentiation between the two groups of samples. The first group included samples from Tauiskaya Bay and waters of Western Kamchatka. The second group consisted of the samples collected in the waters of the Iturup Island (Sea of Okhotsk), Northern Kurile Islands, Navarin region of the Bering Sea, and Anadyr Bay.

  6. Population structure in Atlantic cod in the eastern North Sea-Skagerrak-Kattegat: early life stage dispersal and adult migration.

    Science.gov (United States)

    André, Carl; Svedäng, Henrik; Knutsen, Halvor; Dahle, Geir; Jonsson, Patrik; Ring, Anna-Karin; Sköld, Mattias; Jorde, Per Erik

    2016-02-03

    In marine fish species, where pelagic egg and larvae drift with ocean currents, population structure has been suggested to be maintained by larval retention due to hydrographic structuring and by homing of adult fish to natal areas. Whilst natal homing of adults has been demonstrated for anadromous and coral reef fishes, there are few documented examples of philopatric migration in temperate marine fish species. Here, we demonstrate temporally stable genetic differentiation among spawning populations of Atlantic cod (Gadus morhua L.), and present genetic and behavioural evidence for larval drift and philopatric migration in the eastern North Sea-Skagerrak-Kattegat area. We show that juvenile cod collected in the eastern Skagerrak and central Kattegat are genetically similar to cod from offshore spawning areas in the eastern North Sea. Genetic assignment of individual 2-5 year old fish indicates that cod residing at, or migrating towards, spawning areas in Kattegat and the North Sea display philopatric behaviours. Together these findings suggest a loop between spawning, larval drift and adult return-migrations to spawning areas and underlines that both oceanographic processes and migratory behaviour in the adult phase may be important for stock separation and integrity in marine temperate fishes such as Atlantic cod.

  7. Thermal growth potential of Atlantic cod by the end of the 21st century.

    Science.gov (United States)

    Butzin, Martin; Pörtner, Hans-Otto

    2016-12-01

    Ocean warming may lead to smaller body sizes of marine ectotherms, because metabolic rates increase exponentially with temperature while the capacity of the cardiorespiratory system to match enhanced oxygen demands is limited. Here, we explore the impact of rising sea water temperatures on Atlantic cod (Gadus morhua), an economically important fish species. We focus on changes in the temperature-dependent growth potential by a transfer function model combining growth observations with climate model ensemble temperatures. Growth potential is expressed in terms of asymptotic body weight and depends on water temperature. We consider changes between the periods 1985-2004 and 2081-2100, assuming that future sea water temperatures will evolve according to climate projections for IPCC AR5 scenario RCP8.5. Our model projects a response of Atlantic cod to future warming, differentiated according to ocean regions, leading to increases of asymptotic weight in the Barents Sea, while weights are projected to decline at the southern margin of the biogeographic range. Southern spawning areas will disappear due to thermal limitation of spawning stages. These projections match the currently observed biogeographic shifts and the temperature- and oxygen-dependent decline in routine aerobic scope at southern distribution limits. © 2016 John Wiley & Sons Ltd.

  8. Substantial Downregulation of Myogenic Transcripts in Skeletal Muscle of Atlantic Cod during the Spawning Period

    Science.gov (United States)

    Edvardsen, Vigdis

    2016-01-01

    Gonadal maturation is an extremely energy consuming process for batch spawners and it is associated with a significant decrease in growth and seasonal deterioration in flesh quality. Our knowledge about the molecular mechanisms linking sexual maturation and muscle growth is still limited. In the present study, we performed RNA-Seq using 454 GS-FLX pyrosequencing in fast skeletal muscle sampled from two-year-old Atlantic cod (Gadus morhua) at representative time points throughout the reproductive cycle (August, March and May). In total, 126,937 good quality reads were obtained, with 546 nucleotide length and 52% GC content on average. RNA-Seq analysis using the CLC Genomics Workbench with the Atlantic cod reference UniGene cDNA data revealed 59,581 (46.9%) uniquely annotated reads. Pairwise comparison for expression levels identified 153 differentially expressed UniGenes between time points. Notably, we found a significant suppression of myh13 and myofibrillar gene isoforms in fast skeletal muscle during the spawning season. This study uncovered a large number of differentially expressed genes that may be influenced by gonadal maturation, thus representing a significant contribution to our limited understanding of the molecular mechanisms regulating muscle wasting and regeneration in batch spawners during their reproductive cycle. PMID:26844771

  9. Diel vertical migration of adult Pacific cod Gadus macrocephalus in Alaska.

    Science.gov (United States)

    Nichol, D G; Kotwicki, S; Zimmermann, M

    2013-07-01

    The diel vertical migration (DVM) of Pacific cod Gadus macrocephalus was examined using depth and temperature data from 250 recaptured archival tags deployed on G. macrocephalus in the eastern Bering Sea and in the Gulf of Alaska near Kodiak Island. DVM of two types, deeper during daytime (type I) and deeper during night-time (type II), occurred frequently (15-40% of all days) in G. macrocephalus released at all sites. Most individuals displayed both diel types, with each type of behaviour lasting up to 58 contiguous days, and day and night depth differences averaging c. 8 m. Despite high among-individual variability, the occurrence of DVM varied significantly with the release site, season (i.e. day-of-year) and bottom depth, with the trend in seasonal occurrence nearly opposite for type I compared to type II DVM. No significance could be attributed to G. macrocephalus fork length, sex or ambient (tag) temperature. Trends in the magnitude of G. macrocephalus depth change were observed, with increased movement often occurring during night-time, dawn and dusk, and at release sites where the bathymetry was more complex. Both type I and type II DVMs were attributed to foraging on prey species that also undergo DVM, and increased vertical movements of G. macrocephalus during crepuscular and night-time periods were attributed to more active foraging during dim-light conditions when G. macrocephalus can potentially exploit a sensory advantage over some of their prey. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  10. Cloning and expression analysis of interferon regulatory factor 7 in the Pacific cod, Gadus macrocephalus.

    Science.gov (United States)

    Sun, Hang; Jiang, Zhiqiang; Mao, Mingguang; Huo, Yuan; Han, Yuzhe; Zhang, Saisai

    2016-02-01

    Interferon regulatory factor 7 (IRF7) plays an important role in regulating the response of type I interferon (IFN) to viral infection. To understand the mechanisms underlying immune reactions in the Pacific cod, Gadus macrocephalus, the gene encoding G. macrocephalus IRF7 was cloned and characterized. The cDNA of G. macrocephalus IRF7 was also cloned and sequenced. A cDNA sequence of 2032 bp was assembled using polymerase chain reaction (PCR) products. It contains an open reading frame of 1323 bp in length, which encoded a 440-amino acid polypeptide that comprised a DNA-binding domain (DBD), an IRF association domain (IAD), and a serine-rich domain (SRD). In the DBD, the tryptophan cluster consisted of only four tryptophans, which is a unique characteristic in fish IRF7. The mRNA of IRF7 was detected in various tissues, including in the spleen, thymus, kidney, intestine, and gills, using relative quantification PCR (R-qPCR). Dynamic expression of IRF7 was observed in larvae throughout post-hatching (ph) development, with the highest level detected at day of ph (dph) 25. Response to immune stimulation was examined by challenging larvae with polyriboinosinic polyribocytidylic acid (pIC) to mimic viral infection and elicit an immune reaction. R-qPCR revealed that the expression of IRF7 significantly increased in pIC-treated groups relative to that in the control groups, in a time-dependent manner, with peak responses at 48 and 72 h after pIC-treatment. These results show that IRF7 is expressed in various tissues of adult fish and larvae and is sensitive to viral infection, suggesting that it plays a role in antiviral immune defense in G. macrocephalus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Heavy metals in Pacific cod (Gadus macrocephalus) from the Aleutians: location, age, size, and risk.

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Shukla, Tara; Jeitner, Christian; Burke, Sean; Donio, Mark; Shukla, Sheila; Snigaroff, Ronald; Snigaroff, Daniel; Stamm, Timothy; Volz, Conrad

    2007-11-01

    Considerable attention has been devoted to the risks from mercury (Hg) and polychlorinated biphenyls (PCB) to high-level predators (including humans) who consume freshwater fish. Although the U.S. Food and Drug Administration (FDA) issued advisories because of Hg for four marine fish species, there are few data on lead (Pb), cadmium (Cd), or other metals in Bering Sea fish generally, or on the risk these levels pose to the fish themselves or to consumers of marine fish. Levels of arsenic (As), Cd, chromium (Cr), Pb, Hg, and selenium (Se) levels were examined in muscle and liver of 142 Pacific Cod (Gadus macrocephalus) collected in 2004 at Nikolski, Adak, Amchitka, and Kiska Islands in the Aleutian Chain (Alaska) in the Bering Sea/North Pacific Ocean, a major source of commercial fishing. One key objective was whether there were location, age, gender, and size effects on tissue concentration that might pose a risk to the fish or their predators (including humans). All fish were measured and weighed, and a subset was aged by examining otolith layers. As was higher in liver than in muscle (geometric mean 2420 versus 1590 ng/g or ppb wet weight), as were Cd (GM 224 versus 1.92) and Se (GM 1380 versus 165). Conversely, Cr was higher in muscle (76.8 versus 45 ppb), as were Pb (23.7 vs 12 ppb) and surprisingly Hg (128 versus 82 ppb). Adak, until recently a large military base, had the highest levels of As, Hg, and Se, while Amchitka had the highest Pb levels, but Nikolski, which generally had the lowest levels, had relatively high Pb in liver. In general, interisland differences were significant for most metals in muscle, but only for Cr in liver. Weight and length were positively related to age, but age tended to explain more of the variance in metal levels. The multiple regression relationships differed by tissue in an unanticipated manner. Location contributed significantly to the models for muscle Cd, Pb, Hg, and Se, but not for liver levels. Conversely the length by

  12. Gape morphology of cod Gadus morhua L., haddock Melanogrammus aeglefinus (L.) and whiting Merlangius merlangus (L.) through metamorphosis from larvae to juveniles in the western Irish Sea

    NARCIS (Netherlands)

    Rowlands, W.L.; Dickey-Collas, M.; Geffen, A.J.; Nash, R.D.M.

    2006-01-01

    Variations in standard length (LS), gape size (SG) and jaw length (LJ) were studied in larval and juvenile gadoids (cod Gadus morhua, haddock Melanogrammus aeglefinus and whiting Merlangius merlangus) from 4 to 70 mm. The increase in SG and LJ was not linear with respect to LS. The relationship was

  13. A comparative analysis of legislated and modified Baltic Sea trawlcodends for simultaneously improving the size selection of cod (Gadus morhua) and plaice (Pleuronectes platessa)

    DEFF Research Database (Denmark)

    Wienbeck, Harald; Herrmann, Bent; Feekings, Jordan P.

    2014-01-01

    Five modified trawl codends were assessed for their utility in simultaneously improving the size selectiv-ity of cod (Gadus morhua) and plaice (Pleuronectes platessa) in the Baltic Sea. The modifications includedrefining the selective performance of the current Bacoma codend by increasing the mesh...

  14. Habitat selection of juvenile cod (Gadus morhua), whiting (Merlangus merlangius) and some littoral fish in an aquarium. In: Flødevigen rapportserie no 1, 1987

    OpenAIRE

    Gjøsæter, Jakob

    1987-01-01

    Experiments were conducted to study the habit at selection of juvenile cod Gadus morhua, juvenile whiting merlangus merlangius, black goby Gobius niger, great pipefish Syngnathus acus, sand eel Ammodytes tobianus, butterfish Pholis gunnellus, three-spined stickleback Gasterosteus acculeatus, sea stickleback Spinachia spinachia, goldsinny Ctenolabrus rupestris, and flounder Plathichthys flesus. Aquaria with compartments with algae, with sand and with no substratum were us...

  15. Identification of viral hemorrhagic septicemia virus isolated from Pacific cod Gadus macrocephalus in Prince William Sound Alaska, USA

    Science.gov (United States)

    Meyers, T.R.; Sullivan, J.; Emmenegger, E.; Follett, J.; Short, S.; Batts, W.N.; Winton, J.R.

    1992-01-01

    Ulcerative slun tissues from 2 Pacific cod Gadus rnacrocephalus caught in Prince William Sound, Alaska, USA, were examined for virus by Fish Pathology staff within the F.R.E.D. Division of the Alaska Department of Fish and Game. Six days after inoculation of Epitheliorna papulosum cyprini (EPC) cells at 14"C, diffuse rounding and lifting of cells from the monolayers suggestive of cytopathlc effect became visible in the lower sample dilutions. Ultrastructural examinations of affected EPC cells showed rhabdovirus particles within cytoplasmic vacuoles and on the cell surface membranes. Virus isolates from both cod were subsequently confirmed as viral hemorrhagic septicemia virus (VHSV) by serum neutralizabon and immunoblot assay. This is the first VHSV isolated from Pacific cod, which represents a new host species for the virus. Histologically, cod skin ulcers appeared to be caused by a foreign-body-type inflammatory response to foci of protozoa resembling X cells that also had plasmodial stages. Whether the rhabdovirus was incidental to the slun lesion or played a role in its etiology remains to be determined. The possible relationship between thls virus and the recent occurrences of VHSV in anadromous salmoruds from Washington State, USA, is discussed.

  16. Genome architecture enables local adaptation of Atlantic cod despite high connectivity.

    Science.gov (United States)

    Barth, Julia M I; Berg, Paul R; Jonsson, Per R; Bonanomi, Sara; Corell, Hanna; Hemmer-Hansen, Jakob; Jakobsen, Kjetill S; Johannesson, Kerstin; Jorde, Per Erik; Knutsen, Halvor; Moksnes, Per-Olav; Star, Bastiaan; Stenseth, Nils Chr; Svedäng, Henrik; Jentoft, Sissel; André, Carl

    2017-09-01

    Adaptation to local conditions is a fundamental process in evolution; however, mechanisms maintaining local adaptation despite high gene flow are still poorly understood. Marine ecosystems provide a wide array of diverse habitats that frequently promote ecological adaptation even in species characterized by strong levels of gene flow. As one example, populations of the marine fish Atlantic cod (Gadus morhua) are highly connected due to immense dispersal capabilities but nevertheless show local adaptation in several key traits. By combining population genomic analyses based on 12K single nucleotide polymorphisms with larval dispersal patterns inferred using a biophysical ocean model, we show that Atlantic cod individuals residing in sheltered estuarine habitats of Scandinavian fjords mainly belong to offshore oceanic populations with considerable connectivity between these diverse ecosystems. Nevertheless, we also find evidence for discrete fjord populations that are genetically differentiated from offshore populations, indicative of local adaptation, the degree of which appears to be influenced by connectivity. Analyses of the genomic architecture reveal a significant overrepresentation of a large ~5 Mb chromosomal rearrangement in fjord cod, previously proposed to comprise genes critical for the survival at low salinities. This suggests that despite considerable connectivity with offshore populations, local adaptation to fjord environments may be enabled by suppression of recombination in the rearranged region. Our study provides new insights into the potential of local adaptation in high gene flow species within fine geographical scales and highlights the importance of genome architecture in analyses of ecological adaptation. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  17. Transcriptome profiling of the antiviral immune response in Atlantic cod macrophages.

    Science.gov (United States)

    Eslamloo, Khalil; Xue, Xi; Booman, Marije; Smith, Nicole C; Rise, Matthew L

    2016-10-01

    A study was conducted to determine the transcriptome response of Atlantic cod (Gadus morhua) macrophages to the viral mimic, polyriboinosinic polyribocytidylic acid (pIC), using a 20K Atlantic cod microarray platform and qPCR. We identified 285 significantly up-regulated and 161 significantly down-regulated probes in cod macrophages 24 h after pIC stimulation. A subset of 26 microarray-identified transcripts was subjected to qPCR validation using samples treated with pIC or phosphate-buffered saline (control) over time (3, 6, 12, 24, 48 h), and 77% of them showed a significant response to pIC. The microarray and qPCR analyses in this study showed that pIC induced the expression of cod macrophage transcripts involved in RLR- and TLR-dependent pathogen recognition (e.g. tlr3, tlr7, mda5 and lgp2), as well as signal transducers (e.g. stat1 and nfkbia) and transcription activators (e.g. irf7 and irf10) in the MyD88-independent and dependent signalling pathways. Several immune effectors (e.g. isg15s, viperin, herc4, mip2 and ccl13) were significantly up-regulated in pIC-stimulated cod macrophages. The expression of some transcripts (e.g. irf7, irf10, viperin) was significantly up-regulated by pIC as early as 12 h. All pIC-induced transcripts had peak expression at either 24 h (e.g. tlr7, irf7, mip2) or 48 h (e.g. tlr3, lgp2, stat1). This study suggests possible roles of both vertebrate-conserved (e.g. tlr3 as an up-regulated gene) and fish-specific (tlr22g as a down-regulated gene) receptors in dsRNA recognition, and the importance of conserved and potentially fish-specific interferon stimulated genes in cod macrophages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Harvest selection on Atlantic cod behavioral traits: implications for spatial management.

    Science.gov (United States)

    Olsen, Esben Moland; Heupel, Michelle R; Simpfendorfer, Colin A; Moland, Even

    2012-07-01

    Harvesting wild populations may contrast or reinforce natural agents of selection and potentially cause evolutionary changes in life-history traits such as growth and maturation. Harvest selection may also act on behavioral traits, although this field of research has so far received less attention. We used acoustic tags and a network of receivers to monitor the behavior and fate of individual Atlantic cod (Gadus morhua, N = 60) in their natural habitat on the Norwegian Skagerrak coast. Fish with a strong diel vertical migration, alternating between shallow- and deep-water habitats, had a higher risk of being captured in the fishery (traps, gillnet, hand line) as compared to fish that stayed in deeper water. There was also a significant negative correlation between fish size (30-66 cm) and the magnitude of diel vertical migration. Natural selection on behavior was less clear, but tended to favor fish with a large activity space. On a monthly time scale we found significant repeatabilities for cod behavior, meaning that individual characteristics tended to persist and therefore may be termed personality traits. We argue that an evolutionary approach to fisheries management should consider fish behavior. This would be of particular relevance for spatial management actions such as marine reserve design.

  19. Gender differences in health and aging of Atlantic cod subject to size selective fishery.

    Science.gov (United States)

    Carney Almroth, Bethanie; Sköld, Mattias; Nilsson Sköld, Helen

    2012-09-15

    We have analyzed health and physiological aging parameters in male and female Atlantic cod, Gadus morhua, captured in Kattegat, Skagerrak and in Öresund. Gender differences were clearly evident in a number of variables. Males had longer liver telomeres and higher catalase activities than females, while females had higher superoxide dismutase activity, liver somatic index and condition factor. Effects of age were found for males where levels of the antioxidant glutathione and telomere length declined with age, indicating physiological aging. Liver somatic index increased and percentage oxidized glutathione decreased with age. Between-site comparisons of males show that percentage oxidized glutathione and catalase were lowest in Kattegat, whereas protein carbonyls and condition factor were higher in Skagerrak. Females, on the other hand, showed no differences between sites or indications of somatic aging or age-related effects in egg quality, indicating that older and larger female cod are healthy and show no changes in eggs with age. In contrast, males showed indications of physiological aging and lower condition than females. The results emphasize the importance of conserving old mature fish, in particular high egg-productive females, when managing fisheries.

  20. Gender differences in health and aging of Atlantic cod subject to size selective fishery

    Directory of Open Access Journals (Sweden)

    Bethanie Carney Almroth

    2012-07-01

    We have analyzed health and physiological aging parameters in male and female Atlantic cod, Gadus morhua, captured in Kattegat, Skagerrak and in Öresund. Gender differences were clearly evident in a number of variables. Males had longer liver telomeres and higher catalase activities than females, while females had higher superoxide dismutase activity, liver somatic index and condition factor. Effects of age were found for males where levels of the antioxidant glutathione and telomere length declined with age, indicating physiological aging. Liver somatic index increased and percentage oxidized glutathione decreased with age. Between-site comparisons of males show that percentage oxidized glutathione and catalase were lowest in Kattegat, whereas protein carbonyls and condition factor were higher in Skagerrak. Females, on the other hand, showed no differences between sites or indications of somatic aging or age-related effects in egg quality, indicating that older and larger female cod are healthy and show no changes in eggs with age. In contrast, males showed indications of physiological aging and lower condition than females. The results emphasize the importance of conserving old mature fish, in particular high egg-productive females, when managing fisheries.

  1. Parallel adaptive evolution of Atlantic cod on both sides of the Atlantic Ocean in response to temperature.

    Science.gov (United States)

    Bradbury, Ian R; Hubert, Sophie; Higgins, Brent; Borza, Tudor; Bowman, Sharen; Paterson, Ian G; Snelgrove, Paul V R; Morris, Corey J; Gregory, Robert S; Hardie, David C; Hutchings, Jeffrey A; Ruzzante, Daniel E; Taggart, Chris T; Bentzen, Paul

    2010-12-22

    Despite the enormous economic and ecological importance of marine organisms, the spatial scales of adaptation and biocomplexity remain largely unknown. Yet, the preservation of local stocks that possess adaptive diversity is critical to the long-term maintenance of productive stable fisheries and ecosystems. Here, we document genomic evidence of range-wide adaptive differentiation in a broadcast spawning marine fish, Atlantic cod (Gadus morhua), using a genome survey of single nucleotide polymorphisms. Of 1641 gene-associated polymorphisms examined, 70 (4.2%) tested positive for signatures of selection using a Bayesian approach. We identify a subset of these loci (n=40) for which allele frequencies show parallel temperature-associated clines (pAtlantic. Temperature associations were robust to the statistical removal of geographic distance or latitude effects, and contrasted 'neutral' loci, which displayed no temperature association. Allele frequencies at temperature-associated loci were significantly correlated, spanned three linkage groups and several were successfully annotated supporting the involvement of multiple independent genes. Our results are consistent with the evolution and/or selective sweep of multiple genes in response to ocean temperature, and support the possibility of a new conservation paradigm for non-model marine organisms based on genomic approaches to resolving functional and adaptive diversity.

  2. Purification and characterisation of trypsin-like enzyme from the pyloric caeca of cod (Gadus morhua II

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Beirão

    2001-03-01

    Full Text Available A trypsin -like enzyme from the pyloric caeca of cod (Gadus morhua was purified by affinity chromatography on CHOM Sepharose 4B. Some characteristics were established by its catalytic activity on T.A.M.E., typical enzyme substrate, and serine protease inhibitors. The enzyme had an isoelectric point of 5.30 and 5.89 and was very similar in amino acid composition to bovine trypsin, but differed in having a higher relative amount of acidic amino acids and a lower amount of basic amino acids. The enzyme also hydrolysed fish protein substrates.A tripsina do ceco pilórico do bacalhau (Gadus morhua foi purificada por cromatografia de CHOM Sepharose 4B. Algumas características foram determinadas como atividade catalítica para T.A.M.E., substratos enzimáticos e inibidores de proteases. A enzima mostrou ponto isoelétrico de 5,30 e 5,89 e composição de aminoácidos similar à tripsina bovina, mas diferiu por ter um alto percentual de aminoácidos ácidos e baixo valor em aminoácidos básicos. A tripsina do bacalhau também hidrolisou substratos de proteínas de pescados.

  3. Discarding of cod (Gadus morhua) in the northern cod and northern shrimp directed fisheries from 1980-94

    National Research Council Canada - National Science Library

    Kulka, D.W

    1996-01-01

    .... Cod was discarded from both of these fisheries but amounts were generally under-recorded in the fishing logs and was not accounted for in the landing statistics which are the basis for catch data...

  4. Recruitment variability in North Atlantic cod and match-mismatch dynamics.

    Science.gov (United States)

    Kristiansen, Trond; Drinkwater, Kenneth F; Lough, R Gregory; Sundby, Svein

    2011-03-07

    Fisheries exploitation, habitat destruction, and climate are important drivers of variability in recruitment success. Understanding variability in recruitment can reveal mechanisms behind widespread decline in the abundance of key species in marine and terrestrial ecosystems. For fish populations, the match-mismatch theory hypothesizes that successful recruitment is a function of the timing and duration of larval fish abundance and prey availability. However, the underlying mechanisms of match-mismatch dynamics and the factors driving spatial differences between high and low recruitment remain poorly understood. We used empirical observations of larval fish abundance, a mechanistic individual-based model, and a reanalysis of ocean temperature data from 1960 to 2002 to estimate the survival of larval cod (Gadus morhua). From the model, we quantified how survival rates changed during the warmest and coldest years at four important cod spawning sites in the North Atlantic. The modeled difference in survival probability was not large for any given month between cold or warm years. However, the cumulative effect of higher growth rates and survival through the entire spawning season in warm years was substantial with 308%, 385%, 154%, and 175% increases in survival for Georges Bank, Iceland, North Sea, and Lofoten cod stocks, respectively. We also found that the importance of match-mismatch dynamics generally increased with latitude. Our analyses indicate that a key factor for enhancing survival is the duration of the overlap between larval and prey abundance and not the actual timing of the peak abundance. During warm years, the duration of the overlap between larval fish and their prey is prolonged due to an early onset of the spring bloom. This prolonged season enhances cumulative growth and survival, leading to a greater number of large individuals with enhanced potential for survival to recruitment.

  5. Recruitment variability in North Atlantic cod and match-mismatch dynamics.

    Directory of Open Access Journals (Sweden)

    Trond Kristiansen

    Full Text Available BACKGROUND: Fisheries exploitation, habitat destruction, and climate are important drivers of variability in recruitment success. Understanding variability in recruitment can reveal mechanisms behind widespread decline in the abundance of key species in marine and terrestrial ecosystems. For fish populations, the match-mismatch theory hypothesizes that successful recruitment is a function of the timing and duration of larval fish abundance and prey availability. However, the underlying mechanisms of match-mismatch dynamics and the factors driving spatial differences between high and low recruitment remain poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We used empirical observations of larval fish abundance, a mechanistic individual-based model, and a reanalysis of ocean temperature data from 1960 to 2002 to estimate the survival of larval cod (Gadus morhua. From the model, we quantified how survival rates changed during the warmest and coldest years at four important cod spawning sites in the North Atlantic. The modeled difference in survival probability was not large for any given month between cold or warm years. However, the cumulative effect of higher growth rates and survival through the entire spawning season in warm years was substantial with 308%, 385%, 154%, and 175% increases in survival for Georges Bank, Iceland, North Sea, and Lofoten cod stocks, respectively. We also found that the importance of match-mismatch dynamics generally increased with latitude. CONCLUSIONS/SIGNIFICANCE: Our analyses indicate that a key factor for enhancing survival is the duration of the overlap between larval and prey abundance and not the actual timing of the peak abundance. During warm years, the duration of the overlap between larval fish and their prey is prolonged due to an early onset of the spring bloom. This prolonged season enhances cumulative growth and survival, leading to a greater number of large individuals with enhanced potential for

  6. First feed affects the expressions of microRNA and their targets in Atlantic cod.

    Science.gov (United States)

    Bizuayehu, Teshome Tilahun; Furmanek, Tomasz; Karlsen, Ørjan; van der Meeren, Terje; Edvardsen, Rolf Brudvik; Rønnestad, Ivar; Hamre, Kristin; Johansen, Steinar D; Babiak, Igor

    2016-04-14

    To our knowledge, there is no report on microRNA (miRNA) expression and their target analysis in relation to the type of the first feed and its effect on the further growth of fish. Atlantic cod (Gadus morhua) larvae have better growth and development performance when fed natural zooplankton as a start-feed, as compared with those fed typical aquaculture start-feeds. In our experiment, two groups of Atlantic cod larvae were fed reference feed (zooplankton, mostly copepods, filtered from a seawater pond) v. aquaculture feeds: enriched rotifers (Brachionus sp.) and later brine shrimp (Artemia salina). We examined the miRNA expressions of six defined developmental stages as determined and standardised by body length from first feeding for both diet groups. We found eight miRNA (miR-9, miR-19a, miR-130b, miR-146, miR-181a, miR-192, miR-206 and miR-11240) differentially expressed between the two feeding groups in at least one developmental stage. We verified the next-generation sequencing data using real-time RT-PCR. We found 397 putative targets (mRNA) to the differentially expressed miRNA; eighteen of these mRNA showed differential expression in at least one stage. The patterns of differentially expressed miRNA and their putative target mRNA were mostly inverse, but sometimes also concurrent. The predicted miRNA targets were involved in different pathways, including metabolic, phototransduction and signalling pathways. The results of this study provide new nutrigenomic information on the potential role of miRNA in mediating nutritional effects on growth during the start-feeding period in fish larvae.

  7. Neuromast Formation in the Prehatching Embryos of the Cod Fish, Gadus macrocephalus Tilesius

    OpenAIRE

    Machiko, Otsuka; Shin-ichi, Nagai; Department of Biology, Dokkyo University School of Medicine

    1997-01-01

    To clarify when the free neuromasts of fish become functional, the neuromast formation in the embryonic development of the codfish Gadus macrocephalus Tilesius was investigated. The initial appearance of placodes and an increase in the number and distribution of free neuromasts were followed using light microscopy and scanning electron microscopy. Subsequently, the appearance of afferent and efferent nerve endings of the free neuromasts was investigated by transmission electron microscopy. Se...

  8. Effects of chilled storage and cryopreservation on sperm characteristics, antioxidant enzyme activities, and lipid peroxidation in Pacific cod Gadus microcephalus

    Science.gov (United States)

    Wang, Xueying; Shi, Xuehui; Liu, Yifan; Yu, Daode; Guan, Shuguang; Liu, Qinghua; Li, Jun

    2016-07-01

    The present study evaluated the effects of chilled storage and cryopreservation on sperm motion characteristics, antioxidant enzyme activities, and lipid peroxidation in the Pacific cod Gadus macrocephalus. Sperm motility and the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (Gr), and lipid peroxidation (measured via malondialdehyde (MDA) content) were determined after the milt was stored at 4°C for 12 h, cryopreserved without cryoprotectant in 12% propylene glycol (PG), cryopreserved in 12% PG+0.1 mol/L trehalose, or cryopreserved in 12% PG spermatozoa but centrifuged to decant the supernatant prior to cryopreservation (only sperm cells were cryopreserved). After chilled storage or cryopreservation, the SOD, CAT and GPx activities were reduced in sperm cells and increased in seminal plasma in almost all treatments; sperm motility parameters were also decreased. However, the addition of trehalose into the cryoprotectant could significantly improve the postthaw sperm quality as revealed by the sperm average path velocity. This improvement might be attributed to the function of trehalose in scavenging reactive oxygen species. Chilled storage and cryopreservation had significant effects on sperm motion characteristics, antioxidant enzyme activities, and lipid peroxidation in the Pacific cod.

  9. Free radical scavenging and angiotensin-I converting enzyme inhibitory peptides from Pacific cod (Gadus macrocephalus) skin gelatin.

    Science.gov (United States)

    Ngo, Dai-Hung; Ryu, Bomi; Vo, Thanh-Sang; Himaya, S W A; Wijesekara, Isuru; Kim, Se-Kwon

    2011-12-01

    Potent antioxidative peptides were purified from Pacific cod (Gadus macrocephalus) skin gelatin using alcalase, neutrase, papain, trypsin, pepsin, and α-chymotrypsin. Among them, the papain hydrolysate exhibited the highest antioxidant activity. Therefore, it was further purified and obtained two peptides with amino acid sequences of Thr-Cys-Ser-Pro (388 Da) and Thr-Gly-Gly-Gly-Asn-Val (485.5 Da). The antioxidant activity of the purified peptides was performed by electron spin resonance technique. Moreover, their intracellular free radical scavenging activity using 2',7'-dichlorofluorescin diacetate and the protective effect against oxidation-induced DNA damage were evaluated in mouse macrophages (RAW 264.7 cells). Furthermore, both peptides have shown potential angiotensin-I converting enzyme inhibitory effect. The present study demonstrated that the peptides derived from Pacific cod (G. macrocephalus) skin gelatin could be used in the food industry as functional ingredients with potent antioxidative and antihypertensive benefits. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Linking size and age at sexual maturation to body growth, productivity and recruitment of Atlantic cod stocks spanning the North Atlantic

    DEFF Research Database (Denmark)

    Köster, Fritz; Trippel, E.A.; Tomkiewicz, Jonna

    2013-01-01

    Sexual maturation patterns of 22 North Atlantic stocks of cod (Gadus morhua) were examined and related to geographical distribution area, ambient water temperature, growth and surplus production. Four patterns were identified, i.e. sexual maturation early in life at small size, early in life...... at large size, late in life at small size and lastly, late in life at large size. These maturation patterns were geographically clustered and associated with differences in growth and surplus production. Stocks maturing late in life at small size were characterised by slow growth and low surplus production...... (e.g. stocks in the Gulf of St. Lawrence, Labrador/Newfoundland). Stocks maturing early in life at large size exhibited high to intermediate growth and surplus production (e.g. Celtic Sea, North Sea). Stocks maturing late in life at large size had low to intermediate growth rates and surplus...

  11. Cytomorphological Changes in the Hepate of the White Sea Coastal Cod (Gadus morhua maris-albi Derjugin, 1920 during Parasitic Invasions

    Directory of Open Access Journals (Sweden)

    Shakurova N.V.

    2015-06-01

    Full Text Available The cod Gadus morhua maris-albi is one of the most heavily infested fish species in the White Sea. The fish liver (hepate is a convenient model to study the pathogenesis in parasitosis. A transmission electron microscopy study of the White Sea cod hepatocytes in both minor and severe infestation was performed in this paper. The ultrastructure of hepatocytes and pericytes in minor infestation was analyzed. The signs of fatty liver disease in specimens with the high degree of infestation were revealed. Changes in the fine structure of hepatocytes and adaptation of the organism to parasitosis were discussed.

  12. Prediction of selectivity from morphological conditions: Methodology and a case study on cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Herrmann, Bent; Krag, Ludvig Ahm; Frandsen, Rikke

    2009-01-01

    The FISHSELECT methodology. tools, and software were developed and used to measure the morphological parameters that determine the ability of cod to penetrate different mesh types, sizes, and openings. The shape of one cross-section at the cod's head was found to explain 97.6% of the mesh...

  13. Underwater sound from vessel traffic reduces the effective communication range in Atlantic cod and haddock.

    Science.gov (United States)

    Stanley, Jenni A; Van Parijs, Sofie M; Hatch, Leila T

    2017-11-07

    Stellwagen Bank National Marine Sanctuary is located in Massachusetts Bay off the densely populated northeast coast of the United States; subsequently, the marine inhabitants of the area are exposed to elevated levels of anthropogenic underwater sound, particularly due to commercial shipping. The current study investigated the alteration of estimated effective communication spaces at three spawning locations for populations of the commercially and ecologically important fishes, Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus). Both the ambient sound pressure levels and the estimated effective vocalization radii, estimated through spherical spreading models, fluctuated dramatically during the three-month recording periods. Increases in sound pressure level appeared to be largely driven by large vessel activity, and accordingly exhibited a significant positive correlation with the number of Automatic Identification System tracked vessels at the two of the three sites. The near constant high levels of low frequency sound and consequential reduction in the communication space observed at these recording sites during times of high vocalization activity raises significant concerns that communication between conspecifics may be compromised during critical biological periods. This study takes the first steps in evaluating these animals' communication spaces and alteration of these spaces due to anthropogenic underwater sound.

  14. Small-scale biocomplexity in coastal Atlantic cod supporting a Darwinian perspective on fisheries management.

    Science.gov (United States)

    Olsen, Esben Moland; Knutsen, Halvor; Gjøsæter, Jakob; Jorde, Per Erik; Knutsen, Jan Atle; Stenseth, Nils Chr

    2008-08-01

    Harvesting of marine resources raises concerns about how to identify and preserve biocomplexity, including the diversity of life histories found within and among wild populations of a species. In order to fully accomplish this, there is a need to elucidate the underlying causes of phenotypic variation, and how this variation responds to environmental changes. In general, both evolutionary (genetic) and nonevolutionary (plastic) responses may occur. Plastic responses to environmental change are expected to shift the phenotype along a reaction norm, while an evolutionary response is expected to shift the reaction norm itself. Here, we assess the maturation patterns of coastal Atlantic cod (Gadus morhua) in Skagerrak, where studies using neutral markers have revealed genetically differentiated populations of this harvested fish within tens of kilometres of coastline. Our results suggest that physiological state prior to the spawning season, as well as juvenile growth, both influence the probability of completing sexual maturation at a given age. Furthermore, our results point towards a spatial structuring of this plasticity (i.e. the maturation reaction norms) comparable with population connectivity inferred from neutral markers. We argue that such fine-scale biocomplexity calls for a Darwinian approach to fisheries management.

  15. Regime shifts, resilience and recovery of a cod stock

    DEFF Research Database (Denmark)

    Lindegren, Martin; Diekmann, Rabea; Möllmann, Christian

    2010-01-01

    In the North and Baltic seas Atlantic cod Gadus morhua stocks collapsed as part or one of the major factors inducing large-scale ecosystem regime shifts. Determining the relative contribution of overfishing and climate variability in causing these shifts has proven difficult. While facing similar...... of the local cod stock to environmental change. The recovery and healthy condition of the Sound cod stock illustrate the need for adaptive marine management strategies that maximize ecosystem resilience....

  16. [Formation of genetic diversity in populations of Pacific cod (Gadus macrocephalus Tilesius) (Gadidae)].

    Science.gov (United States)

    Stroganov, A N

    2013-11-01

    The variability of the Gmo3, Gmo34, Gmo35, Pgmo32, Gmo19 microsatellite DNA loci was examined in the population samples of Pacific cod from different parts of the North Pacific. The statistical tests showed that the differentiation of the population was the result of different levels of reproductive autonomy of the individual Pacific cod populations, formed in the Pleistocene-Holocene period with the specific features of transgressions and regressions of the World Ocean, and supported by the existing system of currents and the features of the migratory behavior of cod in the North Pacific.

  17. Maturation Trends Suggestive of Rapid Evolution Preceded the Collapse of Northern Cod

    OpenAIRE

    Olsen, E.M.; Heino, M.; Lilly, G.R.; Morgan, M J; Brattey, J.; Ernande, B.; Dieckmann, U.

    2004-01-01

    Northern cod, comprising populations of Atlantic cod (Gadus morhua) off southern Labrador and eastern Newfoundland, supported major fisheries for hundreds of years. But in the late 1980s and early 1990s, northern cod underwent one of the worst collapses in the history of fisheries. The Canadian government closed the directed fishing for northern cod in July 1992, but even after a decade-long offshore moratorium, population sizes remain historically low. Here we show that, up until the morator...

  18. Mitochondrial acclimation potential to ocean acidification and warming of Polar cod and Atlantic cod (Gadus morhua)

    National Research Council Canada - National Science Library

    Leo, Elettra; Kunz, Kristina L; Schmidt, Matthias; Storch, Daniela; Portner, Hans-O; Mark, Felix C

    2017-01-01

    Ocean acidification and warming are happening fast in the Arctic but little is known about the effects of ocean acidification and warming on the physiological performance and survival of Arctic fish...

  19. Oil droplet fouling and differential toxicokinetics of polycyclic aromatic hydrocarbons in embryos of Atlantic haddock and cod.

    Science.gov (United States)

    Sørensen, Lisbet; Sørhus, Elin; Nordtug, Trond; Incardona, John P; Linbo, Tiffany L; Giovanetti, Laura; Karlsen, Ørjan; Meier, Sonnich

    2017-01-01

    The impact of crude oil pollution on early life stages (ELS) of fish, including larvae and embryos, has received considerable attention in recent years. Of the organic components present in crude oil, polycyclic aromatic hydrocarbons (PAHs) are considered the main class of compounds responsible for toxic effects in marine organisms. Although evidence suggests that they are more toxic, alkylated PAHs remain much less studied than their unsubstituted congeners. Recently, it was established that embryos of Atlantic haddock (Melanogrammus aeglefinus) are particularly sensitive to dispersed crude oil, and it was hypothesized that this was caused by direct interaction with crude oil droplets, which adhered to the chorion of exposed embryos. Such a phenomenon would increase the potential for uptake of less water-soluble compounds, including alkylated PAHs. In the current study, we compared the uptake of parent and alkylated PAHs in Atlantic cod (Gadus morhua) and haddock embryos exposed to dispersed crude oil at a range of environmentally relevant concentrations (10-600 μg oil/liter seawater). Although the species are biologically very similar, the cod chorion does not become fouled with oil droplets, even when the two species are exposed to dispersions of crude oil droplets under similar conditions. A close correlation between the degree of fouling and toxicological response (heart defects, craniofacial malformation) was observed. Oil droplet fouling in haddock led to both quantitative and qualitative differences in PAH uptake. Finally, kinetic data on a large suite of PAHs showed differential elimination, suggesting differential metabolism of unsubstituted versus alkylated compounds.

  20. Male reproductive competition in spawning aggregations of cod ( Gadus morhua , L.)

    DEFF Research Database (Denmark)

    Bekkevold, Dorte; Hansen, Michael Møller; Loeschcke, V.

    2002-01-01

    was dependent on the magnitude of the size difference between a female and a male. We discuss our results in relation to the cod mating system. Finally, we suggest that the highly skewed distribution of paternity success observed in cod may be a factor contributing to the low effective population size......Reproductive competition may lead to a large skew in reproductive success among individuals. Very few studies have analysed the paternity contribution of individual males in spawning aggregations of fish species with huge census population sizes. We quantified the variance in male reproductive...... success in spawning aggregations of cod under experimental conditions over an entire spawning season. Male reproductive success was estimated by microsatellite-based parentage analysis of offspring produced in six separate groups of spawning cod. In total, 1340 offspring and 102 spawnings distributed...

  1. Cod Collapse and Climate in the North Atlantic

    Science.gov (United States)

    Oremus, K. L.; Meng, K. C.; Gaines, S.

    2016-02-01

    Understanding the determinants of fish population dynamics is crucial to the recovery of many fisheries. Current research emphasizes the role of environmental conditions in driving fish populations, but the magnitude of and mechanisms behind these effects on crucial populations are not well established. Despite aggressive management efforts, New England cod fisheries have been in decline for several decades and have now reached unprecedented lows. We find a strong negative relationship between the North Atlantic Oscillation (NAO) and subsequent adult cod biomass and catch. In the Gulf of Maine fishery, a 1-unit NAO increase is associated with a 13% decrease in the biomass of age-1 cod the following year, a decrease that persists as the affected cohort matures. We further detect that a 1-unit NAO increase can lower commercial catch for up to 19 subsequent years, suggesting that fishing practices may be inadvertently exacerbating NAO's direct biological effects. These results imply that 18% and 32% of the overall decline in adult biomass and catch, respectively, since 1980 can be attributed to the NAO's recent multi-decadal positive phase. The Georges Bank cod fishery displays similar patterns. Because there is a delay between an NAO event and subsequent declines in adult biomass, our finding implies that already observed NAO events can be used in stock forecasts, providing lead time for adaptive policy. More broadly, our approach can inform forecasting efforts for other fisheries strongly affected by natural and anthropogenic climatic variation.

  2. Enrichment of metabolites in the cerebrospinal fluid of cod (Gadus morhua) following oral administration of hexachlorobenzene and 2,4',5-trichlorobiphenyl

    Energy Technology Data Exchange (ETDEWEB)

    Ingebrigtsen, K. (Department of Pharmacology and Toxicology, The Norwegian College of Veterinary Medicine, Oslo (Norway) Department of Laboratory Animal Services, National Institute of Public Health, Oslo (Norway)); Hektoen, H. (Norwegian Institute for Water Research, Oslo (Norway)); Andersson, T. (Department of Zoophysiology, University of Goeteborg, Goeteborg (Sweden)); Klasson Wehler, E.; Bergman, Aa. (Environmental Chemistry, Wallenberg Laboratory, Stockholm University, Stockholm (Sweden)); Brandt, I. (Department of Pharmacology and Toxicology, The Swedish University of Agricultural Sciences, Biomedicum, Uppsala (Sweden))

    1992-01-01

    The disposition of [sup 14]C-labelled hexachlorobenzene (HCB) and 2, 4',5-trichlorobiphenyl (triCB) was studied in cod (Gadus morhua) and rainbow trout (Oncorhynchus mykiss). For both compounds tape section autoradiography revealed substantial amounts of radiolabeled material in the central nervous system (CNS) of cod, whereas only traces of radioactivity were observed in the CNS of rainbow trout. Furthermore, an enrichment of radiolabeled compound in the cerebrospinal fluid (CSF) was observed in the cod, whereas no radioactivity could be detected in the CSF of rainbow trout. According to autoradiography, the CNS of cod dosed with HCB contained the parent compound, whereas the major part of radioactivity in CSF was due to HCB metabolites. Thin-layer chromatography of extracts from cod dosed with triCB showed the presence of parent compound in the CNS, whereas part of the radioactivity in the CSF was due to triCB metabolites. The activities of cytochrome P-450 and UDP-glucuronosyltransferase in the CNS of cod and rainbow trout were determined in microsomal and mitochondrial fractions. Both species expressed activities which were in the same order of magnitude as those reported for the corresponding fractions from rat brain. Incubation of triCB with cod brain mitochondria and microsomes resulted in the formation of two polar metabolites. It is suggested that cod may be more vulnerable than rainbow trout regarding neurotoxicological effects of HCB, triCB and related environmental pollutants.

  3. Historic changes in length distributions of three Baltic cod (Gadus morhua) stocks: Evidence of growth retardation.

    Science.gov (United States)

    Svedäng, Henrik; Hornborg, Sara

    2017-08-01

    Understanding how combinations of fishing effort and selectivity affect productivity is central to fisheries research. We investigate the roles of fishing regulation in comparison with ecosystem status for Baltic Sea cod stock productivity, growth performance, and population stability. This case study is interesting because three cod populations with different exploitation patterns and stock status are located in three adjacent but partially, ecologically different areas. In assessing stock status, growth, and productivity, we use survey information and rather basic stock parameters without relying on age readings. Because there is an urgent interest of better understanding of the current development of the Eastern Baltic cod stock, we argue that our approach represents partly a novel way of interpreting monitoring information together with catch data in a simplified yet more informative way. Our study reports how the Eastern and Western Baltic cod have gone toward more truncated size structures between 1991 and 2016, in particular for the Eastern Baltic cod, whereas the Öresund cod show no trend. We suggest that selective fishing may disrupt fish population dynamic stability and that lower natural productivity might amplify the effects of selective fishing. In support of earlier findings on a density-dependent growth of Eastern Baltic cod, management is advised to acknowledge that sustainable exploitation levels for Eastern Baltic cod are much more limited than perceived in regular assessments. Of more general importance, our results emphasize the need to embrace a more realistic view on what ecosystems can produce regarding tractable fish biomass to facilitate a more ecosystem-based fisheries management.

  4. Modeling growth of larval cod ( Gadus morhua) in large-scale seasonal and latitudinal environmental gradients

    Science.gov (United States)

    Kristiansen, Trond; Vikebø, Frode; Sundby, Svein; Huse, Geir; Fiksen, Øyvind

    2009-10-01

    The spawning strategy of cod has evolved through natural selection to give larvae a good start in life. Therefore, larval drift, growth, and survival are key processes to understand spawning strategies. Spawning of Northeast Arctic (NA) cod stretches from late February to early May over 1500 km along the Norwegian coast. Hatching occurs from late March to late May, a period when the number of daylight hours increases from 11 to 17. Larval feeding opportunities are constrained by prey abundance and environmental variables such as light, while temperature determines the maximum growth potential. Here, we model seasonal and latitudinal constraints on larval cod growth by combining predictions from a bio-physically coupled model providing input on nauplii production and development ( Calanus finmarchicus), a 3D physical model (ROMS) providing flow- and temperature-fields, and an individual-based model (IBM) of larval cod physiology and feeding processes. Our aim is to investigate the relative significance of temperature, turbulence, light, and prey density on growth of larval cod by integrative modeling. The models suggest that larval cod experience lower growth if hatched early in the season (prior to mid-April) when the foraging hours are few. Larval cod hatched in early May experience higher temperatures, better growth conditions, and are less susceptible to prey limitation due to increased day-length. We also suggest that increased prey abundance is more valuable early in the spawning season compared to later, when larvae have better feeding conditions. The model quantifies the strong relationship between larval feeding and growth in relation to day-length, time of the season, and water temperature, and the seasonal and spatial appearance of prey.

  5. Predictive analysis of scale-dependent habitat association: Juvenile cod ( Gadus spp.) in eastern Newfoundland

    Science.gov (United States)

    Schneider, David C.; Norris, Michael J.; Gregory, Robert S.

    2008-08-01

    We used results of laboratory experiments to make predictions about a well-established phenomenon, scale-dependent association of organisms with habitat. Based on shelter seeking behaviour in laboratory experiments, we predicted that age 0 cod would be locally decoupled from vegetated habitat at spatial scales on the order of the limits of underwater visibility, becoming associated at larger scales. On transects at 10 sites in Newman Sound, Bonavista Bay, Newfoundland age 0 juvenile cod were usually found either in or adjacent to the band of tall eelgrass running parallel to the coast. At the scale of 5 m or less along transects perpendicular and parallel to the coast cod were decoupled from habitat, as expected. At the scale of 5-20 m cod were either decoupled or only weakly associated with habitat, contrary to expectation based on underwater visibility and shelter seeking behaviour in the lab. At the scale of 20-100 m along transects perpendicular to the coast cod were positively associated with tall eelgrass, while being negatively associated with short eelgrass. This reflects the negative association of tall with short eelgrass due to parallel band structure at this scale. At scales of 20-100 m along transects parallel to the coast cod were positively associated with short eelgrass. Decoupling of cod density from the amount of habitat at scales of 5-20 m was due to the formation of small shoals near the boundaries between tall and short eelgrasses. The observed change in association of numbers with habitat with change in scale, combined with the theoretical expectation that association with habitat decreases as the risk/reward ratio increases, allowed us to draw the conclusion that the ratio of risk to reward decreases as spatial scale increases from 10 to 100 m. The predictive approach we develop here can be extended to other scale-dependent phenomena, such as scale-dependent association of predator with prey.

  6. Mapping the spawning grounds of North Sea cod (Gadus morhua) by direct and indirect means

    Science.gov (United States)

    Fox, Clive J; Taylor, Martin; Dickey-Collas, Mark; Fossum, Petter; Kraus, Gerd; Rohlf, Norbert; Munk, Peter; van Damme, Cindy J.G; Bolle, Loes J; Maxwell, David L; Wright, Peter J

    2008-01-01

    Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton survey to cover the whole North Sea. Also, this survey, conducted in 2004, was the first to make extensive use of DNA-based molecular methods to unambiguously identify early developmental stage cod eggs. We compare the findings from the plankton survey with estimated egg production inferred from the distribution of mature cod in contemporaneous trawl surveys. Results from both approaches were in general agreement and showed hot spots of egg production around the southern and eastern edges of the Dogger Bank, in the German Bight, the Moray Firth and to the east of the Shetlands. These areas broadly coincide with known spawning locations from the period 1940 to 1970. We were, however, unable to directly detect significant numbers of cod eggs at the historic spawning ground off Flamborough (northeast coast of England). The results demonstrate that most of the major spawning grounds of cod in the North Sea are still active but that some localized populations may have been reduced to the point where it is now difficult to detect the presence of eggs in the plankton. PMID:18397869

  7. Effect of calcium-binding peptide from Pacific cod (Gadus macrocephalus) bone on calcium bioavailability in rats.

    Science.gov (United States)

    Peng, Zhe; Hou, Hu; Zhang, Kai; Li, Bafang

    2017-04-15

    Bone collagen peptide with high affinity to Ca was extracted from Pacific cod (Gadus macrocephalus) bone. FTIR spectra of calcium-binding bone collagen peptide showed that band at 3381cm(-1) shifted to 3361cm(-1), 1455cm(-1) moved to 1411cm(-1), and amide II became deeper valley, compared with that of bone collagen peptide. This peptide was sequenced by Q-TOF-MS and sequences of Gly-Pro-Glu-Gly, Gly-Glu-Lys, Gly-Pro-Leu-Gly and Gly-Leu-Pro-Gly appeared repeatedly in some peptides. From SEM, after chelated with calcium, the loose and porous structure turned into granular structure. From the animal experiment, Ca apparent absorption rate, Ca retention rate and femur Ca content of calcium-binding bone collagen peptide group were significantly higher than those of model and CaCO3 groups (P<0.05), while serum ALP was significantly lower than model group (P<0.05) and similar to control group. The results suggested that calcium-binding bone collagen peptide could improve bioavailability of Ca and thus prevented Ca deficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Quantifying environmental heterogeneity : habitat size necessary for successful development of cod Gadus morhua eggs in the Baltic Sea

    DEFF Research Database (Denmark)

    MacKenzie, Brian; Hinrichsen, H.H.; Plikshs, M.

    2000-01-01

    Spatial and temporal variability in environmental factors can exert major influences on survival and growth of living organisms. However, in many key areas of fisheries science (e.g. growth, survival and recruitment determination), environmental heterogeneity is usually ignored because of insuffi......Spatial and temporal variability in environmental factors can exert major influences on survival and growth of living organisms. However, in many key areas of fisheries science (e.g. growth, survival and recruitment determination), environmental heterogeneity is usually ignored because...... of insufficient environmental or fisheries data or lack of evidence that such heterogeneity impacts response variables. For the eastern Baltic Sea (ICES Subdivisions 25 to 32), we evaluated spatial and temporal differences in conditions affecting the survival of cod Gadus morhua L, eggs at survival on four...... distinct spawning sites within the assessment area. We intercalibrated ways of quantifying the volume of water ('reproductive volume') at each site where salinity, oxygen and temperature conditions permitted successful egg development. We have developed and compared a time series (1952 to 1996...

  9. Evaluation of chemical markers for age validation of western Baltic cod (Gadus morhua otoliths

    Directory of Open Access Journals (Sweden)

    Sven Stötera

    2015-11-01

    Baltic cod were intraperitoneally injected with the different chemicals and kept for 47 days in netpens. The lowest mortality and best ring formation was observed at 100mg/kg cod wet weight compared to 50 and 25mg/kg wet weight (TET only. Preliminary analysis suggests that the simultaneous injection of TET and STR decreases the visibility of TET-rings. This is probably due to a binding interaction between both markers in the body of the fish, so that less TET is bound in the otolith. The use of tetracycline hydrochloride in the concentrations of 50 mg/kg and 100 mg/kg fish were considered the most appropriate to mark Baltic cod for age validation in large-scale mark-recapture experiments. TET and STR should not be injected together.

  10. Lipid and fatty acid compositions of cod ( Gadus morhua), haddock ( Melanogrammus aeglefinus) and halibut ( Hippoglossus hippoglossus)

    Science.gov (United States)

    Zeng, Duan; Mai, Kangsen; Ai, Qinghui; Milley, Joyce E.; Lall, Santosh P.

    2010-12-01

    This study was conducted to compare lipid and fatty acid composition of cod, haddock and halibut. Three groups of cod (276 g ± 61 g), haddock (538 g ± 83 g) and halibut (3704 g ± 221 g) were maintained with commercial feeds mainly based on fish meal and marine fish oil for 12 weeks prior to sampling. The fatty acid compositions of muscle and liver were determined by GC/FID after derivatization of extracted lipids into fatty acid methyl esters (FAME). Lipids were also fractionated into neutral and polar lipids using Waters silica Sep-Pak?. The phospholipid fraction was further separated by high-performance thin-layer chromatography (HPTLC) and the FAME profile was obtained. Results of the present study showed that cod and haddock were lean fish and their total muscle lipid contents were 0.8% and 0.7%, respectively, with phospholipid constituting 83.6% and 87.5% of the total muscle lipid, respectively. Halibut was a medium-fat fish and its muscle lipid content was 8%, with 84% of the total muscle lipid being neutral lipid. Total liver lipid contents of cod, haddock and halibut were 36.9%, 67.2% and 30.7%, respectively, of which the neutral lipids accounted for the major fraction (88.1%-97.1%). Polyunsaturated fatty acids were the most abundant in cod and haddock muscle neutral lipid. Monounsaturated fatty acid level was the highest in halibut muscle neutral lipid. Fatty acid compositions of phospholipid were relatively constant. In summary, the liver of cod and haddock as lean fish was the main lipid reserve organ, and structural phospholipid is the major lipid form in flesh. However, as a medium-fat fish, halibut stored lipid in both their liver and muscle.

  11. Degradation of ATP and glycogen in cod ( Gadus morhua ) muscle during freezing

    DEFF Research Database (Denmark)

    Cappeln, Gertrud; Jessen, Flemming

    2001-01-01

    Changes in ATP, IMP, lactate and glycogen contents in the muscle of cod were followed during freezing at temperatures of -20C and -45C. ATP degradation was accompanied by a corresponding increase in IMP content. Simultaneous measurement of temperature showed that at both freezing rates......, the greatest decrease in ATP content was observed when the temperature reached -0.8C. Glycolysis occurred during freezing of cod as indicated by an increase in lactate content. The changes found in all measured metabolites were more pronounced when freezing was performed at a slow rate compared to a fast rate...

  12. Host size-dependent anisakid infection in Baltic cod Gadus morhua associated with differential food preferences

    DEFF Research Database (Denmark)

    Zuo, Shaozhi; Huwer, Bastian; Bahlool, Qusay

    2016-01-01

    suggest that the C. osculatum life cycle in the Baltic Sea includes grey seals as final hosts, sprat as the first transport host and cod as second transport host. It may be speculated that sprat obtain infection by feeding on copepods and/or cladocerans, which could serve as the first intermediate hosts...

  13. Foraging behavior of larval cod ( Gadus morhua ) influenced by prey density and hunger

    DEFF Research Database (Denmark)

    Munk, Peter

    1995-01-01

    Fish larvae meet diverse environmental conditions at sea, and larval growth and chance of survival depend on a flexible response to environmental variability. The present study focuses on the flexibility of the foraging behaviour of larval cod in a series of laboratory experiments on larval search...

  14. Mapping the spawning grounds of North Sea cod ( Gadus morhua ) by direct and indirect means

    DEFF Research Database (Denmark)

    Fox, C.J.; Taylor, M.; Dickey-Collas, M.

    2008-01-01

    Despite recent evidence for sub-stock structuring, North Sea cod are assessed as a single unit. As a consequence, knowledge of sub-stock trends is poor. In particular, there are no recent evaluations of which spawning grounds are active. Here we report results from the first ichthyoplankton surve...

  15. Fishing gear-induced skin ulcerations in Baltic cod, Gadus morhua L

    DEFF Research Database (Denmark)

    Mellergaard, Stig; Bagge, O.

    1998-01-01

    In 1982 a high prevalence of skin ulcerations was observed in Baltic cod in the vicinity of the Danish island of Bornholm. In March the prevalence varied from G to 13%, and in May it had increased to between 26 and 48%. The ulcerations had a sequential development. The initial stage appeared as s...

  16. Selection in the host structures the microbiota associated with developing cod larvae (Gadus morhua).

    Science.gov (United States)

    Bakke, Ingrid; Coward, Eivind; Andersen, Tom; Vadstein, Olav

    2015-10-01

    Marine fish larvae are immature upon hatching, and share their environment with high numbers of bacteria. The microbial communities associated with developing fish larvae might be structured by other factors than those important in developing terrestrial animals. Here, we analysed the beta (β)-diversity of the microbiota associated with developing cod larvae and compared it with the bacterial communities in water and live feed by applying pyrosequencing of bar coded v4 16S rDNA amplicons. A total of 15 phyla were observed in the cod larval microbiota. Proteobacteria was the most abundant, followed by Firmicutes, Bacteroidetes and Actinobacteria. The composition and diversity of the cod larval microbiota changed considerably with age. The temporal and spatial patterns of β-diversity could not be explained by stochastic processes, and did not coincide with changes in the rearing conditions. Furthermore, the larval microbiota was highly distinct from the water and the live feed microbiota, particularly at early developmental stages. However, the similarity between larval and water microbiota increased with age. This study suggests that strong selection in the host structures the cod larval microbiota. The changes in community structure observed with increasing age can be explained by altered selection pressure due to development of the intestinal system. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  17. Effect of catch location, season and quality on value of Icelandic cod (Gadus morhua) products

    DEFF Research Database (Denmark)

    Margeirsson, Sveinn; Nielsen, Allan Aasbjerg; Jonsson, Gudmundur R.

    2006-01-01

    contributions on the effects of natural anti-oxidants to prevent oxidation are also included. Effects of dietary factors on muscle tissue quality, pre-rigor processing and brining of farmed cod are covered. The development of rigor mortis and the quality of muscle in relation to commercial and experimental...

  18. Simulations on the prediction of cod (Gadus morhua) freshness from an intelligent packaging sensor concept

    NARCIS (Netherlands)

    Heising, J.K.; Boekel, van M.A.J.S.; Dekker, M.

    2015-01-01

    A non-destructive method that monitors changes in the freshness status of packed cod fillets has potential for the development of an intelligent packaging concept. The method is based on monitoring volatile compounds that dissolve and dissociate in the sensing aqueous phase. A mathematical model was

  19. Hydroacoustic ex situ target strength measurements on juvenile cod ( Gadus morhua L.)

    DEFF Research Database (Denmark)

    Nielsen, J. Rasmus; Lundgren, Bo

    1999-01-01

    Most TS-measurements on fish have been carried out for 38 kHz, and the existing TS algorithm for 120 kHz on cod is based on measurements on stunned fish. The main objective of these experiments was to establish an empirical estimate of the relation between acoustic reflection (target strength, TS...

  20. Stock recruitment relationships for cod ( Gadus morhua L.) in the central Baltic Sea incorporating environmental variability

    DEFF Research Database (Denmark)

    Jarre, Astrid; Wieland, Kai; MacKenzie, Brian

    2000-01-01

    Recruitment of central/eastern Baltic cod critically depends on favourable oceanographic conditions in the deeper basins of the Baltic Sea creating a suitable habitat for the development of early life stages. The decline in the size of the spawning stock since the mid-1980s initiated a series of ...

  1. Glycolysis and ATP degradation in cod ( Gadus morhua ) at subzero temperatures in relation to thaw rigor

    DEFF Research Database (Denmark)

    Cappeln, Gertrud; Jessen, Flemming

    2001-01-01

    Glycolysis was shown to occur during freezing of cod of decrease in glycogen and an increase in lactate. In addition, the ATP content decreased during freezing. Synthesis of ATP was measured as degradation of glycogen. During storage at -9 and - 12 degreesC it was found that degradation of ATP...

  2. Diseases and parasites of Baltic cod ( Gadus morhua ) from the Mecklenburg Bight to the Estonian coast

    DEFF Research Database (Denmark)

    Mellergaard, Stig; Lang, T.

    1999-01-01

    During the 1994 BMB/ICES Sea-going Workshop "Fish Diseases and Parasites in the Baltic Sea", the prevalences of skin ulcers, pseudobranchial swellings (X-cell disease), skeletal deformities, and the parasites Cryptocotyle lingua and Lernaeocera branchialis were recorded in cod in 11 areas from...

  3. Infection of North Sea cod, Gadus morhua L., larvae with the parasitic nematode Hysterothylacium aduncum Rudolphi

    DEFF Research Database (Denmark)

    Skovgaard, Alf; Bahlool, Qusay Z. M.; Munk, Peter

    2011-01-01

    Investigation of 2197 cod larvae and post-larvae collected in the North Sea revealed high prevalence of infection with a parasitic anisakid nematode identified morphologically and genetically as Hysterothylacium aduncum. Nematodes were third stage larvae and were almost exclusively found in the b...... in the body cavity and they were never encapsulated. Prevalence increased significantly from 1992 to 2001 concomitantly with increased sea temperature. The possibility that the extent of parasitism is influenced by temperature change is discussed....

  4. Miltpain, a cysteine proteinase, from milt of Pacific cod (Gadus macrocephalus): purification and characterization.

    Science.gov (United States)

    Kawabata, C; Doi, Y; Ichishima, E

    2000-04-01

    Miltpain (EC.3.4.22.-) is a cysteine proteinase that preferentially hydrolyzes basic proteins, previously found in the milt of chum salmon. Here we report a similar cysteine proteinase in the milt of the marine Pacific cod. The enzyme was isolated and purified 6900-fold and with an estimated mass of 63 kDa by gel filtration chromatography and 72 kDa by SDS/PAGE. Cod miltpain has an optimum pH of 6.0 for Z-Arg-Arg-MCA hydrolysis, and Km of 11.5 microM and kcat of 19.0 s-1 with Z-Arg-Arg-MCA. It requires a thiol-inducing reagent for activation and is inhibited by E-64, iodoacetamide, CA-074, PCMB, NEM, TLCK, TPCK, ZPCK and o-phenanthroline. This proteinase strongly hydrolyzes basic proteins such as salmine, clupeine and histone, and exhibits unique substrate specificity toward paired basic residues such as Lys-Arg, Arg-Arg on the substrates of P2-P1. The isoelectric point is 5.2 by isoelectric focusing. N-Terminal sequencing gave a sequence of < EVPVEVVRXYVTSAPEK. The cysteine proteinase from Pacific cod very closely matches the previously reported miltpain from chum salmon.

  5. Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua).

    Science.gov (United States)

    Zuo, S; Barlaup, L; Mohammadkarami, A; Al-Jubury, A; Chen, D; Kania, P W; Buchmann, K

    2017-10-01

    Baltic cod livers have during recent years been found increasingly and heavily infected with third-stage larvae of Contracaecum osculatum. The infections are associated with an increasing population of grey seals which are final hosts for the parasite. Heavy worm burdens challenge utilization and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast escape of more than 60% of the worm larvae within 20 min and gave full release within 65 min but the liver tissue became highly dispersed. HCl alone, in concentrations of 48 and 72 mM, triggered a corresponding release of worm larvae with minor effect on liver integrity. A lower HCl concentration of 24 mM resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation, with subsequent release of reaction products, may contribute to activation of C. osculatum larvae and induce escape reactions. Short-term pretreatment of infected cod liver and possibly other infected fish products, using low acid concentrations is suggested as part of a technological solution for worm clearance as low acid concentrations had limited macroscopic effect on liver integrity within 35 min.

  6. MOLECULAR IDENTIFICATION OF Pseudoterranova azarasi LARVAE IN COD (Gadus sp. SOLD FOR HUMAN CONSUMPTION IN BRAZIL

    Directory of Open Access Journals (Sweden)

    Juliana MARIGO

    2015-12-01

    Full Text Available Anisakiasis and Pseudoterranovosis are human diseases caused by the ingestion of live Anisakidae larvae in raw, undercooked or lightly marinated fish. Larvae were collected from one salted cod sold for human consumption in a Sao Paulo market in 2013. One section of one brownish larva was used for molecular analyses. The partial COX2 gene sequence from the larva had a nucleotide identity of 99.8 % with Pseudoterranova azarasi, which belongs to the Pseudoterranova decipiens species complex. The risk of allergy when consuming dead larvae in salted fish is not well known and should be considered.

  7. Hydrographic influence on the spawning habitat suitability of western Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Hüssy, K.; Hinrichsen, H.-H.; Huwer, B.

    2012-01-01

    of early life stages, mediated by environmental conditions of both a physical (water temperature, salinity and oxygen conditions, ocean currents) and a biological nature (i.e. food, predators). The objective of this study is to assess the importance of variability in environmental conditions within...... different western Baltic cod spawning grounds for egg survival. Habitat identification was based on environmental threshold levels for egg survival and development and ambient hydrographical conditions at different times during the spawning season. The long-term resolution of environmental conditions...

  8. Using data storage tags to link otolith macrostructure in Baltic cod Gadus morhua with environmental conditions

    DEFF Research Database (Denmark)

    Hüssy, Karin; Nielsen, Birgitte; Mosegaard, Henrik

    2009-01-01

    We examined otolith opacity of Baltic cod in relation to environmental conditions in order to evaluate the formation mechanisms of seasonal patterns used in age determination. Adult fish were tagged with data storage tags (DSTs) and a permanent mark was induced in the otoliths by injection...... as expected-but in non-spawning fish only. In spawners, the general trend was a decrease in opacity from pre- to post spawning. A significant - but positive - temperature effect was only found in the pre-spawning period. The negative effects during and following spawning were not significant. In spawners...

  9. Why is age determination of Baltic cod (Gadus morhua) so difficult?

    DEFF Research Database (Denmark)

    Hüssy, Karin

    2010-01-01

    to a consistent pattern the following year, and overlap was not influenced by sex or fish size. The results suggest that otolith opacity in Baltic cod is not associated with seasonal patterns in daily increment structure and that traditional age determination based on otolith opacity yields highly uncertain...... similar to opacity patterns. However, within individual fish, the co-occurrence of overlap between the two patterns was random. In cases where there was overlap, translucent zone formation started just before the disappearance of visible increments. Overlap in 1 year did not necessarily lead...

  10. Stage-specific mortality of Baltic cod ( Gadus morhua L.) eggs

    DEFF Research Database (Denmark)

    Wieland, Kai; Hinrichsen, H.H.; Grønkjær, P.

    2000-01-01

    A study on cod egg mortality was carried out in the Bornholm Basin (southern central Baltic Sea) toward the end of July 1996. An initial egg aggregation marked by a satellite-tracked drifter buoy was sampled repeatedly over an Ii-day period; profiles of temperature, salinity and dissolved oxygen...... were concurrently recorded. Three replicate estimates of mortality were obtained for each pair of subsequent developmental stages from newly spawned eggs to early larvae. A consistent pattern of stage-specific mortality coincided well with previous experimental observations. Average daily mortality...... rates were 7.2% (eggs IA/IB), 38.7% (eggs (IB/II), 25.6% (eggs II/III), 40.0% (eggs III/IV), and 42.3% (eggs IV/early larvae). The cumulative mortality until hatch amounted to 99.9%. Results from hydrodynamic modelling, however, indicated that the drifter's trajectory was influenced by wind stress...

  11. Prediction of vertical distribution and ambient development temperature of Baltic cod, Gadus morhua L., eggs

    DEFF Research Database (Denmark)

    Wieland, Kai; Jarre, Astrid

    1997-01-01

    An artificial neural network (ANN) model was established to predict the vertical distribution of Baltic cod eggs. Data from vertical distribution sampling in the Bornholm Basin over the period 1986-1995 were used to train and test the network, while data sets from sampling in 1996 were used...... for validation. The model explained 82% of the variance between observed and predicted relative frequencies of occurrence of the eggs in relation to salinity, temperature and oxygen concentration; The ANN fitted all observations satisfactorily except for one sampling date, where an exceptional hydrographic...... situation was observed. Mean ambient temperatures, calculated from the predicted vertical distributions of the eggs and used for the computation of egg developmental times, were overestimated by 0.05 degrees C on average. This corresponds to an error in prediction of egg developmental time of less than 1%...

  12. Extrusion of Contracaecum osculatum nematode larvae from the liver of cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Zuo, S.; Barlaup, L.; Mohammadkarami, A.

    2017-01-01

    M resulted in 80% release within 35 min. Water and physiological saline had no effect on worm release, and 1% pepsin in water elicited merely a weak escape reaction. In addition to the direct effect of acid on worm behaviour it is hypothesised that the acid effect on calcium carbonate in the encapsulation...... and safety of the fish liver products, and technological solutions for removal of worms are highly needed. We investigated the attachment of the worm larvae in liver tissue by use of histochemical techniques and found that the cod host encapsulates the worm larvae in layers of host cells (macrophages......, fibroblasts) supported by enclosures of collagen and calcium. A series of incubation techniques, applying compounds targeting molecules in the capsule, were then tested for their effect to induce worm escape/release reactions. Full digestion solutions comprising pepsin, NaCl, HCl and water induced a fast...

  13. Analysing migrations of Atlantic cod Gadus morhua in the north‐east Atlantic Ocean

    DEFF Research Database (Denmark)

    Neuenfeldt, S.; Righton, D.; Neat, F.

    2013-01-01

    The application of data storage tags bears the potential for a quantum leap in the research on fish migrations, because not only first-capture and recapture positions are known, but at least theoretically, the migration path during the period at large can be reconstructed. Position, however, cann...

  14. Transport of North Sea cod larvae into the Skagerrak coastal populations.

    OpenAIRE

    Knutsen, Halvor; André, Carl; Jorde, Per Erik; Skogen, Morten D.; Thuróczy, Emma; Stenseth, Nils Chr.

    2004-01-01

    The Atlantic cod (Gadus morhua) is economically one of the world's most important marine species--a species presently suffering from heavy overexploitation throughout its range of distribution. Although not fully understood, the Atlantic cod is believed to be structured into populations in a rather complex manner, whereby both highly migratory and more confined ocean-spawning stocks coexist with stationary coastal populations. Owing to the complex population structure, little is presently kno...

  15. Antioxidant activity of cod (Gadus morhua) protein hydrolysates: Fractionation and characterisation of peptide fractions.

    Science.gov (United States)

    Sabeena Farvin, K H; Andersen, Lisa Lystbæk; Otte, Jeanette; Nielsen, Henrik Hauch; Jessen, Flemming; Jacobsen, Charlotte

    2016-08-01

    This study aimed to characterise peptide fractions (>5kDa, 3-5kDa and <3kDa) with antioxidative activity obtained from a cod protein hydrolysate. The free amino acids in all fractions were dominated by Ala, Gly, Glu and Ser. The total amino acid composition had high proportions of Lys, Ala and Glu. The 3-5kDa and <3kDa fractions were further fractionated by size exclusion chromatography. All sub-fractions showed high Fe(2+) chelating activity. The DPPH radical-scavenging activity of the 3-5kDa fraction was exerted mainly by one sub-fraction dominated by peptides with masses below 600Da. The DPPH radical-scavenging activity of the <3kDa fraction was exerted by sub-fractions with low molecular weight. The highest reducing power was found in a sub-fraction containing peptides rich in Arg, Tyr and Phe. Both free amino acids and low molecular weight peptides thus seemed to contribute to the antioxidative activity of the peptide fractions, and Tyr seemed to play a major role in the antioxidant activity. Copyright © 2016. Published by Elsevier Ltd.

  16. Long-term stability and effective population size in North Sea and Baltic Sea cod ( Gadus morhua )

    DEFF Research Database (Denmark)

    Poulsen, Nina Aagaard; Eg Nielsen, Einar; Schierup, M.H.

    2006-01-01

    for the Moray Firth population, while subtle but significant genetic changes over time were detected for the Bornholm Basin population. Estimates of the effective population size (N-e) generally exceeded 500 for both populations when employing a number of varieties of the temporal genetic method. However......, confidence intervals were very wide and N-e's most likely range in the thousands. There was no apparent loss of genetic variability and no evidence of a genetic bottleneck for either of the populations. Calculations of the expected levels of genetic variability under different scenarios of N-e showed...... that the number of alleles commonly reported at microsatellite loci in Atlantic cod is best explained by N-e's exceeding thousand. Recent fishery-induced bottlenecks can, however, not be ruled out as an explanation for the apparent discrepancy between high levels of variability and recently reported estimates...

  17. Oil droplet fouling and differential toxicokinetics of polycyclic aromatic hydrocarbons in embryos of Atlantic haddock and cod

    Science.gov (United States)

    Sørhus, Elin; Nordtug, Trond; Incardona, John P.; Linbo, Tiffany L.; Giovanetti, Laura; Karlsen, Ørjan; Meier, Sonnich

    2017-01-01

    The impact of crude oil pollution on early life stages (ELS) of fish, including larvae and embryos, has received considerable attention in recent years. Of the organic components present in crude oil, polycyclic aromatic hydrocarbons (PAHs) are considered the main class of compounds responsible for toxic effects in marine organisms. Although evidence suggests that they are more toxic, alkylated PAHs remain much less studied than their unsubstituted congeners. Recently, it was established that embryos of Atlantic haddock (Melanogrammus aeglefinus) are particularly sensitive to dispersed crude oil, and it was hypothesized that this was caused by direct interaction with crude oil droplets, which adhered to the chorion of exposed embryos. Such a phenomenon would increase the potential for uptake of less water-soluble compounds, including alkylated PAHs. In the current study, we compared the uptake of parent and alkylated PAHs in Atlantic cod (Gadus morhua) and haddock embryos exposed to dispersed crude oil at a range of environmentally relevant concentrations (10–600 μg oil/liter seawater). Although the species are biologically very similar, the cod chorion does not become fouled with oil droplets, even when the two species are exposed to dispersions of crude oil droplets under similar conditions. A close correlation between the degree of fouling and toxicological response (heart defects, craniofacial malformation) was observed. Oil droplet fouling in haddock led to both quantitative and qualitative differences in PAH uptake. Finally, kinetic data on a large suite of PAHs showed differential elimination, suggesting differential metabolism of unsubstituted versus alkylated compounds. PMID:28678887

  18. Oil droplet fouling and differential toxicokinetics of polycyclic aromatic hydrocarbons in embryos of Atlantic haddock and cod.

    Directory of Open Access Journals (Sweden)

    Lisbet Sørensen

    Full Text Available The impact of crude oil pollution on early life stages (ELS of fish, including larvae and embryos, has received considerable attention in recent years. Of the organic components present in crude oil, polycyclic aromatic hydrocarbons (PAHs are considered the main class of compounds responsible for toxic effects in marine organisms. Although evidence suggests that they are more toxic, alkylated PAHs remain much less studied than their unsubstituted congeners. Recently, it was established that embryos of Atlantic haddock (Melanogrammus aeglefinus are particularly sensitive to dispersed crude oil, and it was hypothesized that this was caused by direct interaction with crude oil droplets, which adhered to the chorion of exposed embryos. Such a phenomenon would increase the potential for uptake of less water-soluble compounds, including alkylated PAHs. In the current study, we compared the uptake of parent and alkylated PAHs in Atlantic cod (Gadus morhua and haddock embryos exposed to dispersed crude oil at a range of environmentally relevant concentrations (10-600 μg oil/liter seawater. Although the species are biologically very similar, the cod chorion does not become fouled with oil droplets, even when the two species are exposed to dispersions of crude oil droplets under similar conditions. A close correlation between the degree of fouling and toxicological response (heart defects, craniofacial malformation was observed. Oil droplet fouling in haddock led to both quantitative and qualitative differences in PAH uptake. Finally, kinetic data on a large suite of PAHs showed differential elimination, suggesting differential metabolism of unsubstituted versus alkylated compounds.

  19. On the prediction of short term changes in the recruitment of North Sea cod (Gadus morhua using statistical temperature forecasts

    Directory of Open Access Journals (Sweden)

    Benjamin Planque

    2003-04-01

    Full Text Available Empirical evidence supports the hypothesis of a general relationship between sea temperature and recruitment of cod stocks across the North Atlantic, as well as between recruitment and the size of the spawning population. In the North Sea, cod year-class strength is inversely related to sea surface temperature during the first half of the year. This stock is currently at a low level, and the future trajectory of the stock biomass will be strongly influenced by recruitment levels. In the present study we investigate the possible use of observed and modelled sea surface temperature (SST to increase the accuracy and/or time horizon of recruitment forecasts for this stock. We show that the statistical model developed for forecasting spring temperature has good skill (35% skill, with a standard error of 0.36°C when predictions are made in late January. Within the frame of the current fish stock assessment working group we incorporate SST observations and January forecasts and simulate short-term recruitment projections. The resulting model accounts for a greater fraction of the variance in recruitment (42% than that obtained without temperature (17%. In operational mode, the model allows forecasting 1.5 years in advance but the accuracy of predicted recruitment remains low. This example indicates that we have not yet reached a point where environmental information can be used with great benefit for the management of North Sea cod. However, a similar strategy may yield greater benefits if developed for other stocks for which environmental effects are better understood and/or account for a larger fraction of the variability in recruitment, for species with a shorter generation time and species for which recruitment forecast is critical to management (e.g. anchovy, and in areas where environmental prediction capabilities may be greater either in accuracy or in lead time.

  20. A follow-up study of selected biomarkers of health in cod Gadus morhua L. collected from the southern Baltic off the Polish coast.

    Science.gov (United States)

    Borucinska, J D; Morka, D; Grabowski, Z; Smith, H

    2017-12-01

    Selected biomarkers of health were examined in 50 post-spawning cod Gadus morhua collected in November 2015 from the southern Baltic. The biomarkers included condition factor (CF), macroscopic lesions, histopathology of spleen, liver and gonads, and morphometry of follicular atresia and hepatic and splenic melanomacrophage cells (MMC). All fish appeared in good body condition. One fish had a dermal ulcer, and in seven, macroscopic nematodes were noted within body cavity. Microscopic lesions in the liver included biliary myxozoanosis, microsporidial and necrocentric granulomas, parasitic hepatitis, multifocal necrosis, foci of cellular alterations, spongiosis, peliosis and cytoplasmic fibrillar inclusions. The spleen and gonads had microsporidial and/or necrocentric granulomas. Some of the biomarkers showed differences as compared to spawning cod collected in May from the same location in 2012, most importantly values an order of magnitude lower for splenic MMC in post-spawning fish. In post-spawning fish, there were statistically significant correlations between MMC, CF, follicular atresia, parasitic hepatitis and microsporidiosis. This is the first comparison of biomarkers of health in post-spawning and spawning Baltic cod. Future studies need to examine the relationships of biomarkers to levels of pollutants in the environment and in tissues of cod. © 2017 John Wiley & Sons Ltd.

  1. Interactive effects of incubation temperature and salinity on the early life stages of pacific cod Gadus macrocephalus

    Science.gov (United States)

    Bian, Xiaodong; Zhang, Xiumei; Sakurai, Yasunari; Jin, Xianshi; Wan, Ruijing; Gao, Tianxiang; Yamamoto, Jun

    2016-02-01

    The combined effects of incubation temperature and salinity on the early life stages of Pacific cod Gadus macrocephalus were examined under controlled laboratory conditions. Data were collected from two synchronized experiments. Experiment 1 was designed to evaluate the interactive effects of incubation temperature and salinity on the hatchability of fertilized G. macrocephalus eggs. Experiment 2 was set up to evaluate the interactive effects of incubation temperature and salinity on the time from hatching to 50% mortality of the non-fed yolk-sac larvae (M50). The results show that temperature could significantly influence the development and hatchability of the larvae, as well as the hatching characteristics of G. macrocephalus. Viable hatch was significantly influenced by salinity when the upper and lower thermal limits were approached and shows the synergism of low salinity on egg development at low-temperatures and conversely inhibitory effects of low-salinity at high-temperatures. Data on developmental rates as influenced by temperature were presented at each tested salinity level. No influence of salinity was found at the temperature levels tested. Dome-shaped quadratic curves were fitted to the relationship between temperature and the incidence of larval size and yolk storage at hatch for most of the tested salinity levels. The effect of salinity across all temperatures, however, had a much smaller influence on larval size and no effect on yolk storage at hatch. The influence of temperature on larval duration (time from hatching to M50) could be described in all cases by an exponential power function. Evidence on the synergism of low salinity at low-temperatures and conversely inhibitory effects of low-salinity at high-temperatures was also observed. The results were discussed in reference to salinity modified temperature effects on the early life stages of G. macrocephalus. Maximum hatchability and larval size at hatch, and moderate salinity tolerance and

  2. [Genetic variation at the pantophysin (PanI) locus in North-East Arctic cod Gadus morhua L. (Gadiformes: Gadidae) population in the Barents Sea and adjacent waters].

    Science.gov (United States)

    Makeenko, G A; Volkov, A A; Mugue, N S; Zelenina, D A

    2014-12-01

    We investigated polymorphisms in the pantophysin gene (Pan I locus) in a population of North-East Arctic cod, Gadus morhua L., throughout its foraging area in the Barents Sea and adjacent waters. Correlations between the frequencies of Pan I alleles and habitat conditions, such as depth and temperature, were explored. This study was based on a large number of specimens (2210 individuals) of different age and wide geographic sampling coverage. The frequency of the Pan I(A) allele, a known genetic marker of coastal cod, varied from zero to 0.47. Allele frequencies correlated with depth at the sampling location but not with bottom water temperatures. We observed variations in Pan I(A) frequencies among different age cohorts from the same area. The most prominent shift in Pan I polymorphism was detected at the early stages of the fish life cycle, between pelagic juveniles and benthic cod. We found that the Pan I(A) allele frequency in pelagic yearling cod was essentially same throughout the studied areas in the Barents Sea. In turn, juveniles settling at the northern and deep water locations showed a significant decrease in the allele frequency. In contrast, the frequency of the Pan I(A) allele remained constant in juveniles settling in shallow waters when compared to the pelagic stage. These results confirm the selective nature of the cod Pan I locus and indicate that selection process acting on individuals with different genotypes at the Pan I locus leads to the formation of a stable spatial distribution of allele frequencies observed in adult cod.

  3. Forecasting the Major Influences of Predation and Environment on Cod Recovery in the Northern Gulf of St. Lawrence

    OpenAIRE

    Nicolas Bousquet; Emmanuel Chassot; Duplisea, Daniel E.; Mike O Hammill

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring thi...

  4. Distribution and elimination of (/sup 14/C)octachlorostyrene in cod (Gadus morhua), rainbow trout (Salmo gairdneri, and blue mussel (Mytilus edulis)

    Energy Technology Data Exchange (ETDEWEB)

    Ingebrigtsen, K.; Solbakken, J.E.; Norheim, G.; Nafstad, I.

    1988-01-01

    Cod (Gadus morhua) and rainbow trout (Salmo gairdneri) were given a single oral dose of 100 microCi/kg b.w. of (/sup 14/C)octachlorostyrene ((/sup 14/C)OCS) in peanut oil. Blue mussel (Mytilus edulis) was exposed to (/sup 14/C)OCS in water. The distribution and elimination of the compound was studied by liquid scintillation counting and whole-body autoradiography. The highest degree of radioactivity in the cod and rainbow trout was measured in the liver and the visceral fat, respectively. The degree of radioactivity in the brain of cod exceeded that of the rainbow trout by a factor between 2 and 4 at all survival times. In addition to bile excretion of (/sup 14/C)OCS-derived radioactivity, a possible excretion over the intestinal mucosa was suggested. The rate of elimination was slow in both species, and substantial amounts of radioactivity remained in the tissues 90 d after administration. In the blue mussel, the highest degree of radioactivity was found in the hepatopancreas. Substantial amounts of radioactivity were present in the mussel tissues 60 d after administration.

  5. Interactions between small pelagic fish and young cod across the north Atlantic.

    Science.gov (United States)

    Minto, Cóilín; Worm, Boris

    2012-10-01

    Species interactions that play out over large spatial scales are difficult to observe, particularly in the oceans. The current lack of empirical evidence for biologically meaningful interaction parameters likely delays the application of holistic management procedures. Here we estimate interactions during the early life history of fish across regions. We present separate and hierarchical Bayesian models that estimate the direction and strength of interactions between Atlantic cod and dominant pelagic fishes across much of their range in the North Atlantic. We test the hypothesis that small pelagic fish may reduce survival of cod at early life stages, and thereby contribute to the delayed recovery of depleted cod populations. Significant regional variation exists between cod recruitment and Atlantic herring abundance with eight of 14 regions displaying a negative relationship, four regions displaying no relationship, and a positive relationship observed in two regions. In contrast, most regions where Atlantic mackerel co-occurs showed no relationship with cod recruitment, with the possible exception of Gulf of St. Lawrence and Celtic Sea regions. Regions with sprat or capelin as dominant pelagics also displayed weak or no relationship, although the probability of a negative interaction with sprat increased when time series autocorrelation was accounted for. Overall, the interaction between herring and young cod was found to be negative with 94% probability, while the probability of negative interactions with mackerel was only 68%. Our findings suggest that the strength of predation or competition effects on young cod varies among small pelagic species but appears consistently for Atlantic herring; this effect may need to be considered in recovery trajectories for depleted cod populations. The methods introduced here are applicable in the investigation of species interactions from time series data collected across different study systems.

  6. Slave to the rhythm: seasonal signals in otolith microchemistry reveal age of eastern Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Hüssy, Karin; Gröger, J.; Heidemann, F.

    2016-01-01

    Annual growth zones in cod otoliths from the eastern Baltic stock are less discrete than in other cod stocks leading to biased age reading, which recently led to a failure of age-based assessment in the eastern Baltic cod stock. In this study, we explored the applicability of minor and trace...... element patterns in cod otoliths for age determination. By first identifying elements of interest in a stock without ageing problems, western Baltic cod, we then tested their applicability on another stock without ageing problems, North Sea cod, and finally applied this knowledge to estimate age...... significance of the local profile minima were identified, based on which their age could be estimated. Despite extensive environmental differences between the three areas examined, the element concentrations of Cu, Zn, and Rb were strongly correlated in all individuals with similar correlations in all three...

  7. Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

    OpenAIRE

    Krag, Ludvig Ahm

    2009-01-01

    For the last decade, the Kattegat-Skagerrak and the North Sea cod stocks have been at a critically low level. Several management initiatives were introduced to protect and aid the recovery of these cod stocks. Most fisheries in these areas are conducted in a multispecies setting, where several different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the hi...

  8. Genomic divergence between the migratory and stationary ecotypes of Atlantic cod.

    Science.gov (United States)

    Karlsen, Bård O; Klingan, Kevin; Emblem, Åse; Jørgensen, Tor E; Jueterbock, Alexander; Furmanek, Tomasz; Hoarau, Galice; Johansen, Steinar D; Nordeide, Jarle T; Moum, Truls

    2013-10-01

    Atlantic cod displays a range of phenotypic and genotypic variations, which includes the differentiation into coastal stationary and offshore migratory types of cod that co-occur in several parts of its distribution range and are often sympatric on the spawning grounds. Differentiation of these ecotypes may involve both historical separation and adaptation to ecologically distinct environments, the genetic basis of which is now beginning to be unravelled. Genomic analyses based on recent sequencing advances are able to document genomic divergence in more detail and may facilitate the exploration of causes and consequences of genome-wide patterns. We examined genomic divergence between the stationary and migratory types of cod in the Northeast Atlantic, using next-generation sequencing of pooled DNA from each of two population samples. Sequence data was mapped to the published cod genome sequence, arranged in more than 6000 scaffolds (611 Mb). We identified 25 divergent scaffolds (26 Mb) with a higher than average gene density, against a backdrop of overall moderate genomic differentiation. Previous findings of localized genomic divergence in three linkage groups were confirmed, including a large (15 Mb) genomic region, which seems to be uniquely involved in the divergence of migratory and stationary cod. The results of the pooled sequencing approach support and extend recent findings based on single-nucleotide polymorphism markers and suggest a high degree of reproductive isolation between stationary and migratory cod in the North-east Atlantic. © 2013 John Wiley & Sons Ltd.

  9. Multi-decadal responses of a cod (Gadus morhua) population to human-induced trophic changes, fishing, and climate

    DEFF Research Database (Denmark)

    Eero, Margit; MacKenzie, Brian; Köster, Fritz

    2011-01-01

    significant climate-driven variations in cod recruitment production at multi-annual timescales, which had major impacts on population dynamics and the yields to commercial fisheries. We also quantify the roles of marine mammal predation, eutrophication, and exploitation on the development of the cod...

  10. Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm

    different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the highest discard rates of juvenile fish, including cod. The focus of this work was on improving...... the selectivity of demersal trawling with regard to cod. This Ph.D. thesis consists of a review and four supporting papers (1-4). Two main techniques are used to aid fish in escaping from fishing gear. The first technique involves a process of mechanical sorting based on fish size and the second is based...... of this study was to improve the size selection for cod in the fisheries directed towards Nephrops. Paper 2 describes a new methodology, tools, and software that have been developed and used to measure the morphological parameters that determine the ability of cod to penetrate different mesh types, sizes...

  11. Temperature during early development has long-term effects on microRNA expression in Atlantic cod.

    Science.gov (United States)

    Bizuayehu, Teshome Tilahun; Johansen, Steinar D; Puvanendran, Velmurugu; Toften, Hilde; Babiak, Igor

    2015-04-17

    Environmental temperature has serious implications in life cycle of aquatic ectotherms. Understanding the molecular mechanisms of temperature acclimation and adaptation of marine organisms is of the uttermost importance for ecology, fisheries, and aquaculture, as it allows modeling the effects of global warming on population dynamics. Regulatory molecules are major modulators of acclimation and adaptation; among them, microRNAs (miRNAs) are versatile and substantial contributors to regulatory networks of development and adaptive plasticity. However, their role in thermal plasticity is poorly known. We have asked whether the temperature and its shift during the early ontogeny (embryonic and larval development) affect the miRNA repertoire of Atlantic cod (Gadus morhua), and if thermal experience has long-term consequences in the miRNA profile. We characterized miRNA during different developmental stages and in juvenile tissues using next generation sequencing. We identified 389 putative miRNA precursor loci, 120 novel precursor miRNAs, and 281 mature miRNAs. Some miRNAs showed stage- or tissue-enriched expression and miRNAs, such as the miR-17 ~ 92 cluster, myomiRs (miR-206), neuromiRs (miR-9, miR-124), miR-130b, and miR-430 showed differential expression in different temperature regimes. Long-term effect of embryonic incubation temperature was revealed on expression of some miRNAs in juvenile pituitary (miR-449), gonad (miR-27c, miR-30c, and miR-200a), and liver (let-7 h, miR-7a, miR-22, miR-34c, miR-132a, miR-192, miR-221, miR-451, miR-2188, and miR-7550), but not in brain. Some of differentially expressed miRNAs in the liver were confirmed using LNA-based rt-qPCR. The effect of temperature on methylation status of selected miRNA promoter regions was mostly inconclusive. Temperature elevation by several degrees during embryonic and larval developmental stages significantly alters the miRNA profile, both short-term and long-term. Our results suggest that a further

  12. Remarkably low mtDNA control-region diversity and shallow population structure in Pacific cod Gadus macrocephalus.

    Science.gov (United States)

    Liu, M; Lu, Z C; Gao, T X; Yanagimoto, T; Sakurai, Y

    2010-10-01

    To investigate the genetic diversity and describe the population structure in Gadus macrocephalus, a 452 base pair (bp) fragment of the mitochondrial DNA control region was analysed in 259 individuals. The results showed remarkably low nucleotide diversity and a lack of genealogical structure. Small but significant genetic differentiations, however, were detected among north-western Pacific populations, but no large-scale regional differences were detected. These results indicate that populations of G. macrocephalus in the north-western Pacific are genetically subdivided and represent evolutionary lineages that should be managed individually. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

  13. Synergies between climate and management for Atlantic cod fisheries at high latitudes.

    Science.gov (United States)

    Kjesbu, Olav Sigurd; Bogstad, Bjarte; Devine, Jennifer A; Gjøsæter, Harald; Howell, Daniel; Ingvaldsen, Randi B; Nash, Richard D M; Skjæraasen, Jon Egil

    2014-03-04

    The widespread depletion of commercially exploited marine living resources is often seen as a general failure of management and results in criticism of contemporary management procedures. When populations show dramatic and positive changes in population size, this invariably leads to questions about whether favorable climatic conditions or good management (or both) were responsible. The Barents Sea cod (Gadus morhua) stock has recently increased markedly and the spawning stock biomass is now at an unprecedented high. We identify the crucial social and environmental factors that made this unique growth possible. The relationship between vital rates of Barents Sea cod stock productivity (recruitment, growth, and mortality) and environment is investigated, followed by simulations of population size under different management scenarios. We show that the recent sustained reduction in fishing mortality, facilitated by the implementation of a "harvest control rule," was essential to the increase in population size. Simulations show that a drastic reduction in fishing mortality has resulted in a doubling of the total population biomass compared with that expected under the former management regime. However, management alone was not solely responsible. We document that prevailing climate, operating through several mechanistic links, positively reinforced management actions. Heightened temperature resulted in an increase in the extent of the suitable feeding area for Barents Sea cod, likely offering a release from density-dependent effects (for example, food competition and cannibalism) through prolonged overlap with prey and improved adult stock productivity. Management and climate may thus interact to give a positive outlook for exploited high-latitude marine resources.

  14. Effects of light conditions and temperature gradients on vertical migration behavior of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma)

    Science.gov (United States)

    Flanders, K. R.; Laurel, B.

    2016-02-01

    Early life stages of marine fishes must maximize growth while minimizing vulnerability to predators. Larval stages in particular are subject to ocean currents, but encounter favorable habitats by adjusting their vertical position in the water column. The investigation of environmental cues that change larval fish behavior is therefore crucial to understanding larval drift and dispersal modeling, and subsequently population structure and connectivity. In this study, the behavioral responses of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma) in a vertical water column were examined. Two prominent environmental variables, light and temperature, were manipulated over 3 h during observational trials. Light intensity was studied at two levels (1.484 x 101 μE m-2 s-1 ; 2.54 x102 μE m-2 s-1), and a diel effect was studied through the removal of light after 2 h. Light intensity did not significantly impact the position of either species in a vertical water column. However, a significant difference by species was apparent when all light levels were considered: the mean position of Arctic cod was closer to the surface of the water than that of walleye pollock. The effect of temperature through the introduction of a thermocline (range 5.6°C - 1.5°C) was limited to walleye pollock given the Arctic cod larvae were surface oriented across all light treatments. However, the thermocline did not significantly impact the relative change in position from light to dark in walleye pollock, likely because they were also surface oriented in control treatments. These results could be incorporated into future larval dispersal and survival models, particularly in Alaskan and Arctic waters, to investigate changes in species distributions resulting from global warming impacts. These results also indicate population structures of Arctic cod and walleye pollock could be affected, which may be reflected in ecosystem and trophic interactions. Because Arctic cod

  15. 1H NMR metabolic profiling of cod (Gadus morhua) larvae: potential effects of temperature and diet composition during early developmental stages.

    Science.gov (United States)

    Chauton, Matilde Skogen; Galloway, Trina Falck; Kjørsvik, Elin; Størseth, Trond Røvik; Puvanendran, Velmurugu; van der Meeren, Terje; Karlsen, Ørjan; Rønnestad, Ivar; Hamre, Kristin

    2015-11-06

    Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development. © 2015. Published by The Company of Biologists Ltd.

  16. 1H NMR metabolic profiling of cod (Gadus morhua larvae: potential effects of temperature and diet composition during early developmental stages

    Directory of Open Access Journals (Sweden)

    Matilde Skogen Chauton

    2015-12-01

    Full Text Available Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development.

  17. Effect of netting direction and number of meshes around on size selection in the codend for Baltic cod (Gadus morhua)

    DEFF Research Database (Denmark)

    Wienbeck, Harald; Herrmann, Bent; Moderhak, Waldemar

    2011-01-01

    We investigated experimentally the effect that turning the netting direction 90° (T90) and halving the number of meshes around in the circumference in a diamond mesh codend had on size selection of Baltic cod. The results generally agreed with predictions of a previous simulation-based study. Both...... modifications had a significant positive effect on the size selection of cod. The best selection results were obtained for a codend in which both factors were applied together. For that codend, very little between-haul variation in cod size selection was detected, especially compared to the reference codend...

  18. Extracellular glucose supports lactate production but not aerobic metabolism in cardiomyocytes from both normoglycemic Atlantic cod and low glycemic short-horned sculpin.

    Science.gov (United States)

    Clow, Kathy A; Short, Connie E; Driedzic, William R

    2016-05-01

    Fish exhibit a wide range of species-specific blood glucose levels. How this relates to glucose utilization is yet to be fully realized. Here, we assessed glucose transport and metabolism in myocytes isolated from Atlantic cod (Gadus morhua) and short-horned sculpin (Myoxocephalus scorpius), species with blood glucose levels of 3.7 and 0.57 mmol l(-1), respectively. Glucose metabolism was assessed by the production of (3)H2O from [2-(3)H]glucose. Glucose metabolism was 3.5- to 6-fold higher by myocytes from Atlantic cod than by those from short-horned sculpin at the same level of extracellular glucose. In Atlantic cod myocytes, glucose metabolism displayed what appears to be a saturable component with respect to extracellular glucose, and cytochalasin B inhibited glucose metabolism. These features revealed a facilitated glucose diffusion mechanism that accounts for between 30% and 55% of glucose entry at physiological levels of extracellular glucose. Facilitated glucose diffusion appears to be minimal in myocytes for short-horned sculpin. Glucose entry by simple diffusion occurs in both cell types with the same linear relationship between glucose metabolism and extracellular glucose concentration, presumably due to similarities in membrane composition. Oxygen consumption by myocytes incubated in medium containing physiological levels of extracellular glucose (Atlantic cod 5 mmol l(-1), short-horned sculpin 0.5 mmol l(-1)) was similar in the two species and was not decreased by cytochalasin B, suggesting that these cells have the capability of oxidizing alternative on-board metabolic fuels. Cells produced lactate at low rates but glycogen levels did not change during the incubation period. In cells from both species, glucose utilization assessed by both simple chemical analysis of glucose disappearance from the medium and (3)H2O production was half the rate of lactate production and as such extracellular glucose was not available for oxidative metabolism

  19. Improving the size- and species selectivity of cod (Gadus morhua) in demersal mixed-species trawl fisheries

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm

    have been published in scientific journals and Paper 3 has been submitted to Fisheries Research. This review will take a broader perspective and will examine the capturing process, which is the basis for the selection process. Moreover, it discusses the existing methods and knowledge in the fields......For the last decade, the Kattegat-Skagerrak and the North Sea cod stocks have been at a critically low level. Several management initiatives were introduced to protect and aid the recovery of these cod stocks. Most fisheries in these areas are conducted in a multispecies setting, where several...... different species, including cod, are caught together. Demersal trawling is the predominant fishing method in Denmark, as measured by both catch value and volume. Demersal trawls also account for the highest discard rates of juvenile fish, including cod. The focus of this work was on improving...

  20. How may feeding data be integrated into a model for a Norwegian fjord population of cod (Gadus morhua L. ?

    Directory of Open Access Journals (Sweden)

    Torstein Pedersen

    2003-04-01

    Full Text Available We investigate how cod feeding data may be included into a recently developed age-structured model for a coastal cod population in a small fjord in northern Norway. The model integrates data from mark-recapture experiments, trawl-surveys and commercial catches. The fjord population has high biomass density (2-3 tonnes km-2 and low fishing mortality rates (F

  1. Multi-decadal responses of a cod (Gadus morhua) population to human-induced trophic changes, fishing, and climate.

    Science.gov (United States)

    Eero, Margit; MacKenzie, Brian R; Köster, Friedrich W; Gislason, Henrik

    2011-01-01

    Understanding how human impacts have interacted with natural variability to affect populations and ecosystems is required for sustainable management and conservation. The Baltic Sea is one of the few large marine ecosystems worldwide where the relative contribution of several key forcings to changes in fish populations can be analyzed with empirical data. In this study we investigate how climate variability and multiple human impacts (fishing, marine mammal hunting, eutrophication) have affected multi-decadal scale dynamics of cod in the Baltic Sea during the 20th century. We document significant climate-driven variations in cod recruitment production at multi-annual timescales, which had major impacts on population dynamics and the yields to commercial fisheries. We also quantify the roles of marine mammal predation, eutrophication, and exploitation on the development of the cod population using simulation analyses, and show how the intensity of these forcings differed over time. In the early decades of the 20th century, marine mammal predation and nutrient availability were the main limiting factors; exploitation of cod was still relatively low. During the 1940s and subsequent decades, exploitation increased and became a dominant forcing on the population. Eutrophication had a relatively minor positive influence on cod biomass until the 1980s. The largest increase in cod biomass occurred during the late 1970s, following a long period of hydrographically related above-average cod productivity coupled to a temporary reduction in fishing pressure. The Baltic cod example demonstrates how combinations of different forcings can have synergistic effects and consequently dramatic impacts on population dynamics. Our results highlight the potential and limitations of human manipulations to influence predator species and show that sustainable management can only be achieved by considering both anthropogenic and naturally varying processes in a common framework.

  2. Optimization and comparison of miniaturized extraction techniques for PAHs from crude oil exposed Atlantic cod and haddock eggs.

    Science.gov (United States)

    Sørensen, Lisbet; Silva, Marta S; Booth, Andy M; Meier, Sonnich

    2016-02-01

    Two miniaturized extraction methods for a wide range of 2-6 ring polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues in small lipid-rich biota samples (≤100 mg) have been developed. Both methods utilize liquid extraction (LE) prior to a clean-up step using either normal phase solid phase extraction (SPE) or mixed-phase dispersive SPE (dSPE). Optimization of the methods was achieved by comparing the type and amount of sorbents, drying agents, and solvents used. In order to improve the limits of detection (LOD) of target PAHs under high sensitivity gas chromatography-tandem mass spectrometry analysis, specific emphasis was given to minimizing lipid co-extraction. The optimized LE-SPE method comprised extraction with dichloromethane/n-hexane (1:1, v/v) and clean-up by silica SPE, whereas the optimized LE-dSPE method comprised extraction with acetonitrile and clean-up with PSA and C18 sorbents. The methods were validated and directly compared through the analysis of Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) eggs exposed to oil. The LE-SPE method resulted in lower levels of co-extracted lipids (14.1 ± 1.7 ng/μL) than the LE-dSPE method (60 ± 14 ng/μL). Achieved PAH LODs for the LE-SPE method were typically an order of magnitude lower (fish eggs (~100 mg) exposed to small quantities of crude oil (~1-10 μg/L total PAHs).

  3. Microevolution in time and space: SNP analysis of historical DNA reveals dynamic signatures of selection in Atlantic cod.

    Science.gov (United States)

    Therkildsen, Nina O; Hemmer-Hansen, Jakob; Als, Thomas D; Swain, Douglas P; Morgan, M Joanne; Trippel, Edward A; Palumbi, Stephen R; Meldrup, Dorte; Nielsen, Einar E

    2013-05-01

    Little is known about how quickly natural populations adapt to changes in their environment and how temporal and spatial variation in selection pressures interact to shape patterns of genetic diversity. We here address these issues with a series of genome scans in four overfished populations of Atlantic cod (Gadus morhua) studied over an 80-year period. Screening of >1000 gene-associated single-nucleotide polymorphisms (SNPs) identified 77 loci that showed highly elevated levels of differentiation, likely as an effect of directional selection, in either time, space or both. Exploratory analysis suggested that temporal allele frequency shifts at certain loci may correlate with local temperature variation and with life history changes suggested to be fisheries induced. Interestingly, however, largely nonoverlapping sets of loci were temporal outliers in the different populations and outliers from the 1928 to 1960 period showed almost complete stability during later decades. The contrasting microevolutionary trajectories among populations resulted in sequential shifts in spatial outliers, with no locus maintaining elevated spatial differentiation throughout the study period. Simulations of migration coupled with observations of temporally stable spatial structure at neutral loci suggest that population replacement or gene flow alone could not explain all the observed allele frequency variation. Thus, the genetic changes are likely to at least partly be driven by highly dynamic temporally and spatially varying selection. These findings have important implications for our understanding of local adaptation and evolutionary potential in high gene flow organisms and underscore the need to carefully consider all dimensions of biocomplexity for evolutionarily sustainable management. © 2013 Blackwell Publishing Ltd.

  4. Influence of photoperiod on expression of DNA (cytosine-5) methyltransferases in Atlantic cod.

    Science.gov (United States)

    Giannetto, Alessia; Nagasawa, Kazue; Fasulo, Salvatore; Fernandes, Jorge M O

    2013-05-01

    Photoperiod manipulation during early juvenile stages can influence growth in Atlantic cod. In the present study, one group of cod juveniles were reared under natural photoperiod conditions for Bodø (67° N, 14° E), whereas their counterparts were kept under continuous illumination. The mean weight of juvenile cod reared under continuous illumination was found to be 13% greater than those kept under natural photoperiod after 120days of light treatment. The molecular basis of this phenotypic plasticity is currently unknown but it is likely that DNA (cytosine-5)-methyltransferases (dnmts) are involved, since these genes play a crucial role in epigenetic regulation of gene expression. Phylogenetic analysis of Atlantic cod dnmt1, dnmt2 and dnmt3a revealed that within each group, the phylogeny follows the taxonomic relationship between the various species and comparative mapping of dnmt paralogues showed that these genes lie within regions of conserved synteny amongst teleosts. Of the three dnmt paralogues, dnmt3a had the highest expression in fast muscle of adult cod. In addition, dnmt1 and dnmt2 were differentially expressed between tissues but with prominent expression in gonads. Dnmt1 and dnmt3a transcript levels showed a significant increase in fast muscle of juvenile cod from the continuous light group at several time points. Remarkably, dnmt1 and dnmt3a transcript levels were 2-fold higher at 120days, by which point photoperiod conditions between the two light groups had become identical. Our data revealed that photoperiod can have an extended effect on expression of dnmt genes, which may be involved in the epigenetic regulation of muscle growth by photoperiod in Atlantic cod. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Combined application of modified atmosphere packaging and superchilled storage to extend the shelf life of fresh cod (Gadus morhua) loins.

    Science.gov (United States)

    Wang, T; Sveinsdóttir, K; Magnússon, H; Martinsdóttir, E

    2008-01-01

    Development of new technologies and preservation methods to offer conveniently packed fish with sufficient keeping quality is important to meet increasing demand for value-added fresh fish products on the market. The aim of this study was to investigate the effect of combined application of modified atmosphere packaging (MAP) and superchilled storage on the shelf life of fresh cod loins. Fresh cod loins were packed in polystyrene boxes and in MA (CO(2)/N(2)/O(2): 50%/45%/5%) on day 3 postcatch and stored at chilled (1.5 degrees C) and superchilled (-0.9 degrees C) temperatures. Quantitative descriptive analysis (QDA) and physical, chemical, and microbial analyses were carried out during the 21 d of storage. Superchilled storage alone compared with traditional chilled storage in polystyrene boxes increased the total shelf life (days from catch) of cod loins from 9 to 16 or 17 d. Chilled MA packaging increased the shelf life from 9 to 14 d and when MAP and superchilled storage were combined, a synergistic effect was observed and the shelf life was further extended to at least 21 d. It is noteworthy that the characteristic fresh and sweet taste can be maintained longer under such conditions. This could contribute to enhanced eating quality of fresh cod fillets for consumers in distant markets. However, MAP combined with superchilled storage resulted in different textural properties. Superchilled MA packed cod loins had more meaty texture compared to other sample groups after 7-d storage.

  6. The use of otolith microstructure to estimate age in adult Atlantic cod Gadus morhua

    DEFF Research Database (Denmark)

    Hüssy, Karin; Hinrichsen, H.H.; Fey, D.P.

    2010-01-01

    primordium of the otolith. Increment formation apparently ceased at temperatures cold months corresponded closely with estimated growth rates. The increment patterns seemed to reflect annual cycles in environmental temperature, and the count of the increment cycles may thus...... to be tightly coupled to the annual cycle in environmental temperature at a depth of 30–60 m, where G. morhua predominantly reside. Between 135 and 200 increments occurred within the different zones, with a non-significant trend towards lower increment numbers and widths with distance from the primary...

  7. Catch-and-release of Atlantic cod (Gadus morhua) in recreational fisheries

    OpenAIRE

    Ferter, Keno

    2015-01-01

    The role of recreational fisheries in the exploitation pressure on fish resources is increasingly recognized. This has led to the introduction of new harvest regulations for several European marine recreational fisheries. Such regulations have been shown to increase the practice of regulatory catch-and-release (C&R). Additionally, anglers have been shown to practice voluntary C&R due to various personal motivations. Access-point surveys in two study areas in Northern and Southern Norway found...

  8. Differences in growth and survival between cod Gadus morhua and herring Clupea harengus early stages co-reared at variable prey concentrations.

    Science.gov (United States)

    Folkvord, A; Vollset, K W; Catalán, I A

    2015-11-01

    It was hypothesized that the survival and growth strategies of herring Clupea harengus, displaying a flexible reproductive activity, are adapted to coping with longer periods of prey deprivation (i.e. more variable prey availability), in contrast to cod Gadus morhua, which are adapted to match growth and survival at high prey concentrations. Experimental larval growth and survival data for the two naturally co-occurring species reared either in separate tanks or in combination are presented to test this hypothesis. Natural zooplankton was supplied either ad libitum or in a periodically restricted manner to mimic natural suboptimal conditions. Periodically restricted feeding significantly reduced initial growth of G. morhua larvae co-reared with C. harengus, while no such initial effect was seen for co-reared C. harengus. Overall survival of G. morhua was higher when reared together with C. harengus (32 v. 24%), while C. harengus had higher survival without the presence of G. morhua (59 v. 44%), indicating that both species were affected by higher densities of G. morhua larvae. Furthermore, the final survival in G. morhua was inversely related to average final size, while in C. harengus an opposite trend was observed. How potential behavioural interactions may drive the present results are discussed and contended that a better insight into field vital rates may be gained from further exploration of co-rearing experiments. © 2015 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

  9. Distribution and elimination of (/sup 14/C)-hexachlorobenzene after single oral exposure in cod (Gadus morhua) and flounder (Platichthys flesus)

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. A study of lipid- and water-soluble arsenic species in liver of Northeast Arctic cod (Gadus morhua) containing high levels of total arsenic

    DEFF Research Database (Denmark)

    Sele, Veronika; Sloth, Jens Jørgen; Julshamn, Kale

    2015-01-01

    In the present study liver samples (n = 26) of Northeast Arctic cod (Gadus morhua), ranging in total arsenic concentrations from 2.1 to 240 mg/kg liver wet weight (ww), were analysed for their content of total arsenic and arsenic species in the lipid-soluble and water-soluble fractions. The arsenic...... concentrations in the lipid fractions ranged from 1.8 to 16.4 mg As/kg oil of liver, and a linear correlation (r(2) = 0.80, p arsenic concentrations in liver and the total arsenic concentrations in the respective lipid fractions of the same livers. The relative proportion...... of arsenolipids was considerably lower in liver samples with high total arsenic levels (33-240 mg/kg ww), which contained from 3 to 7% of the total arsenic in the lipid-soluble fraction. In contrast liver samples with low arsenic concentrations (2.1-33 mg/kg ww) contained up to 50% of the total arsenic as lipid...

  11. Host condition and accumulation of metals by acanthocephalan parasite Echinorhynchus gadi in cod Gadus morhua from the southern Baltic Sea.

    Science.gov (United States)

    Podolska, M; Polak-Juszczak, L; Nadolna-Ałtyn, K

    2016-12-15

    In this study, we analyzed the relationship between concentration of metals in the host-parasite system (cod - acanthocephalan Echinorhynchus gadi) and Fulton's condition factor (FCF) of the host. The relationship between metal (Ca, Cd, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Pb, Sr, Zn) concentrations in E. gadi and cod tissues was expressed as a bioconcentration factor (BCF), the ratio of the concentration in the parasite tissue to that in host tissues. Acanthocephalans accumulated mainly toxic metals (Cd, Pb), as well as Sr, Ca, Na. Cadmium showed the highest bioconcentration in parasites (BCF >200) compared to fish muscle. Significant negative correlation was detected between FCF and the concentration of Cd and Hg in cod liver. In contrast, FCF was positively correlated with the concentration of Hg in acanthocephalan tissues. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A robust method for compiling trawl survey data used in the assessment of central Baltic cod ( Gadus morhua L.)

    DEFF Research Database (Denmark)

    Sparholt, H.; Tomkiewicz, Jonna

    2000-01-01

    Annual stratified bottom trawl surveys have been used since 1982 to estimate cod abundance in the central Baltic Sea. Catch at age from national research vessels is included in a common database, but data compilation is hampered by large differences in fishing power between vessels, mainly due...... of adult cod of all ages aggregated to minimise the effects of age determination discrepancies. The established index of spawning stock biomass did not correlate significantly better with VPA estimates than simpler indices ignoring depth stratification and fishing power. However, the method is preferable...... because it considers factors known to influence survey trawl catches....

  13. Development of international fisheries for the eastern Baltic cod ( Gadus morhua ) from the late 1880s until 1938

    DEFF Research Database (Denmark)

    Eero, Margit; MacKenzie, Brian; Karlsdottir, H.M.

    2007-01-01

    of indicators of fishing effort and qualitative information on developments in fishing technology. This information has been assembled for different countries and locations in the Baltic Sea. We first summarize the multi-decadal development of national cod fisheries and their relative importance during...... the first decades of the 20th century. We then assess whether these data can be used to estimate the relative roles of fishing and ecosystem changes on variations in catches. We conclude that the assembled data reveal biologically meaningful variations in the state of the cod stock and that some...

  14. Three chromosomal rearrangements promote genomic divergence between migratory and stationary ecotypes of Atlantic cod.

    Science.gov (United States)

    Berg, Paul R; Star, Bastiaan; Pampoulie, Christophe; Sodeland, Marte; Barth, Julia M I; Knutsen, Halvor; Jakobsen, Kjetill S; Jentoft, Sissel

    2016-03-17

    Identification of genome-wide patterns of divergence provides insight on how genomes are influenced by selection and can reveal the potential for local adaptation in spatially structured populations. In Atlantic cod - historically a major marine resource - Northeast-Arctic- and Norwegian coastal cod are recognized by fundamental differences in migratory and non-migratory behavior, respectively. However, the genomic architecture underlying such behavioral ecotypes is unclear. Here, we have analyzed more than 8.000 polymorphic SNPs distributed throughout all 23 linkage groups and show that loci putatively under selection are localized within three distinct genomic regions, each of several megabases long, covering approximately 4% of the Atlantic cod genome. These regions likely represent genomic inversions. The frequency of these distinct regions differ markedly between the ecotypes, spawning in the vicinity of each other, which contrasts with the low level of divergence in the rest of the genome. The observed patterns strongly suggest that these chromosomal rearrangements are instrumental in local adaptation and separation of Atlantic cod populations, leaving footprints of large genomic regions under selection. Our findings demonstrate the power of using genomic information in further understanding the population dynamics and defining management units in one of the world's most economically important marine resources.

  15. Oceanographic influences on the distribution of Baltic cod, Gadus morhua , during spawning in the Bornholm Basin of the Baltic Sea

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Lehmann, K.M.; St. John, Michael

    1998-01-01

    The Baltic Sea is a stratified, semi-enclosed sea typified by a low-salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing r...

  16. A model-based evaluation of Marine Protected Areas: the example of eastern Baltic cod (Gadus morhua callarias L.)

    DEFF Research Database (Denmark)