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| | 1. |
2011 Apr 18 |
Reactive oxygen species: Are they important for haematopoiesis?
Sardina JL, López-Ruano G, Sánchez-Sánchez B, Llanillo M, Hernández-Hernández A
Crit Rev Oncol Hematol. 2011 Apr 18; [Epub ahead of print]
Abstract
The production of reactive oxygen species (ROS) has traditionally been related to deleterious effects for cells. However, it is now widely accepted that ROS can play an important role in regulating cellular signalling and gene expression. NADPH oxidase ROS production seems to be especially important in this regard. Some lines of evidence suggest that ROS may be important modulators of cell differentiation, including haematopoietic differentiation, in both physiologic and pathologic conditions. Here we shall review how ROS can regulate cell signalling and gene expression. We shall also focus on the importance of ROS for haematopoietic stem cell (HSC) biology and for haematopoietic differentiation. We shall review the involvement of ROS and NADPH oxidases in cancer, and in particular what is known about the relationship between ROS and haematological malignancies. Finally, we shall discuss the use of ROS as cancer therapeutic targets.
[Pubmed: 21507675]
| | 2. |
2011 Jun 24 |
A case study of trace metals in suspended particulate matter and biota before wastewater treatment plant from the Izmir Bay, Turkey.
Kontas A
Environ Monit Assess. 2011 Jun 24; [Epub ahead of print]
Abstract
The concentrations of trace metals (Cu, Zn, Mn, Ni, and Fe) from suspended particulate matter (SPM) and biota in Izmir Bay (Eastern Aegean Sea) were studied in order to evaluate the environmental impact of the anthropogenic metals before building of Wastewater Treatment Plant. SPM samples were collected in wet and dry periods from Izmir Bay. Metal concentrations in SPM (Cu, 0.36-2.19; Mn, 0.07-11.3; Ni, 0.43-7.81; Zn, 7.33-269; Fe, 1.00-266 μgdm( - 3)) were comparable to those reported for other moderately polluted bays. Maximum metal concentrations in SPM were observed during summer season. SPM metal concentrations displayed a clear spatial trend with values increasing with proximity to urban centers. Cu and Zn concentrations in SPM were especially high in the inner bay. SPM were found to be contaminated by Zn. The vertical profile of Mn, Zn, and Ni concentrations in SPM had a maximal value at the upper layer and decreased to minimal value at the bottom layer of the inner bay in summer, in contrast to the observed pattern of Fe and Cu. Maximum Cu concentrations were obtained in Penaeus kerathurus. Also, maximum Zn and Fe concentrations were found in Mytilus galloprovincialis. Relatively high Cu levels were found in Sardina pilcardus and Mullus barbatus than other fish species. Besides, Cu levels were lower in Diplodus annularis and Merluccius merluccius. Finally, metal levels in biota tissues were lower than the limits of European Dietary Standards and Guidelines.
[Pubmed: 21701893]
| | 3. |
2011 Jun 24 |
Polymorphisms of beta-lactoglobulin promoter region in three Sicilian goat breeds.
Sardina MT, Rosa AJ, Davoli R, Braglia S, Portolano B
Mol Biol Rep. 2011 Jun 24; [Epub ahead of print]
Abstract
Several beta-lactoglobulin (BLG) polymorphisms have been described within the proximal promoter region and coding region of the caprine gene, although no genetic variants affecting the protein amino acid composition and/or expression level have been characterized so far. Binding sites for several transcription factors (TFs) are present in the BLG promoter region. The aims of this work were to sequence the full-length promoter region of three Sicilian goat breeds in order to identify polymorphisms, analyze the identified haplotypes, search for differences between breeds for the presence of polymorphisms in this gene region, search for putative TFs binding sites, and check if polymorphisms lay within the identified TFs binding sites. The promoter region of BLG gene in Sicilian goat breeds showed high level of polymorphism due to the presence of 36 single nucleotide polymorphisms (SNPs). Association between polymorphic sites was computed within the whole sample analyzed and 18 haplotypes were inferred. Binding sites for three milk protein binding factors (MPBFs) and four nuclear factor-I (NF-I) were found within BLG promoter region based on the ovine sequence. The identification of some SNPs within TFs binding sites allowed hypothesizing the loss of TFs. Further studies are in progress to evaluate the effect of these mutations on binding affinity of TFs, the functional interaction of the TFs with the goat BLG promoter, and the relationship of the polymorphisms with BLG gene expression and milk production and composition.
[Pubmed: 21701825]
| | 4. |
2011 Aug 10 |
Cloning and Characterization of a Novel Oligoalginate Lyase from a Newly Isolated Bacterium Sphingomonas sp. MJ-3.
Park HH, Kam N, Lee EY, Kim HS
Mar Biotechnol (NY). 2011 Aug 10; [Epub ahead of print]
Abstract
A bacterium possessing alginate-degrading activity was isolated from marine brown seaweed soup liquefied by salted and fermented anchovy. The isolated strain was designated as Sphingomonas sp. MJ-3 based on the analyses of 16S ribosomal DNA sequences, 16S-23S internal transcribed spacer region sequences, biochemical characteristics, and cellular fatty acid composition. A novel alginate lyase gene was cloned from genomic DNA library and then expressed in Escherichia coli. When the deduced amino acid sequence was compared with the sequences on the databases, interestingly, the cloned gene product was predicted to consist of AlgL (alginate lyase L)-like and heparinase-like protein domain. The MJ-3 alginate lyase gene shared below 27.0% sequence identity with exolytic alginate lyase of Sphingomonas sp. A1. The optimal pH and temperature for the recombinant MJ-3 alginate lyase were 6.5 and 50°C, respectively. The final degradation products of alginate oligosaccharides were analyzed by electrospray ionization mass spectrometry and proved to be alginate monosaccharides. Based on the results, the recombinant alginate lyase from Sphingomonas sp. MJ-3 is regarded as an oligoalginate lyase that can degrade oligoalginate and alginate into alginate monosaccharides.
[Pubmed: 21826589]
| | 5. |
2011 Oct 19 |
The effects of extraction methods on the contents of fatty acids, especially EPA and DHA in marine lipids.
Ozogul Y, Simşek A, Balikçi E, Kenar M
Int J Food Sci Nutr. 2011 Oct 19; [Epub ahead of print]
Abstract
This study aims to evaluate the efficiency of trans-methylation methods in fish oil obtained using Soxhlet extraction method and Bligh and Dyer method and also to observe the effects of extraction methods on the contents of polyunsaturated fatty acids [PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in five marine species: sardine (Sardinella aurita), anchovy (Engraulis encrasicolus), sea bream (Sparus aurata), brushtooth lizardfish (Saurida undosquamis) and chub mackerel (Scomber japonicus). The results showed that Bligh and Dyer extraction method was more efficient in extracting polar and non-polar lipids than Soxhlet method and also prevented losses of PUFAs by a reduction in the oxidation. The level of EPA showed fluctuations for the two extraction methods. However, Soxhlet method showed significant decrease (p < 0.05) in the level of DHA for all fish species. The use of n-heptane proves to be superior for the recovery of unsaturated fatty acids, especially EPA and DHA.
[Pubmed: 22010951]
| | 6. |
2011 Nov 6 |
Polycyclic aromatic hydrocarbon levels in three pelagic fish species from Atlantic Ocean: Inter-specific and inter-season comparisons and assessment of potential public health risks.
Ramalhosa MJ, Paíga P, Morais S, Ramos S, Delerue-Matos C, Oliveira MB
Food Chem Toxicol. 2011 Nov 6; [Epub ahead of print]
Abstract
The concentrations of 18 polycyclic aromatic hydrocarbons (PAHs) were determined in three commercially valuable fish species (sardine, Sardine pilchardus; chub mackerel, Scomber japonicus; and horse mackerel, Trachurus trachurus) from the Atlantic Ocean. Specimens were collected seasonally during 2007-2009. Only low molecular weight PAHs were detected, namely, naphthalene, acenaphthene, fluorene and phenanthrene. Chub mackerel (1.80-19.90μg/kgww) revealed to be significantly more contaminated than horse mackerel (2.73-10.0μg/kgww) and sardine (2.29-14.18μg/kgww). Inter-specific and inter-season comparisons of PAHs bioaccumulation were statistically assessed. The more relevant statistical correlations were observed between PAH amounts and total fat content (significant positive relationships, p⩽0.05), and season (sardine displayed higher amounts in autumn-winter while the mackerel species showed globally the inverse behavior). The health risks by consumption of these species were assessed and shown to present no threat to public health concerning PAH intakes.
[Pubmed: 22079181]
| | 7. |
2011 Dec 7 |
Biochemical properties of recombinant leucine aminopeptidase II from Bacillus stearothermophilus and potential applications in the hydrolysis of Chinese anchovy (Engraulis japonicus) proteins.
Wang F, Ning Z, Lan D, Liu Y, Yang B, Wang Y
J Agric Food Chem. 2011 Dec 7; [Epub ahead of print]
Abstract
The effects of various factors on the activity and conformation of recombinant leucine aminopeptidase II (rLAP II) from Bacillus stearothermophilus and its potential utilization in the hydrolysis of anchovy proteins were investigated. The optimal temperature and pH of rLAP II were 55 °C and 8.0 in phosphate buffer, and its activity was strongly stimulated by Co2+. Conformational studies indicated that maintaining the α-helical structure had a critical effect on rLAP II activity. rLAP II was used to hydrolyze anchovy proteins, and it exhibited high specificity for peptides with molecular weight between 6000 Da and 1000 Da and positive coordination with endogenous enzymes and commercial Flavourzyme. Its use will enhance protein hydrolysis in species of aquatic animals. rLAP II could potentially be used to remove bitterness in the protein hydrolysis industry.
[Pubmed: 22148180]
| | 8. |
2012 Jan 4 |
Radioactivity and heavy metal concentrations of some commercial fish species consumed in the Black Sea Region of Turkey.
Korkmaz Görür F, Keser R, Akçay N, Dizman S
Chemosphere. 2012 Jan 4; [Epub ahead of print]
Abstract
Marine fish is an important daily diet item for the people of Turkey. The Black Sea Region of Turkey was contaminated by the Chernobyl accident in 1986, a comprehensive study was planned and carried out to determine the radioactivity levels ((226)Ra, (232)Th, (40)K and (137)Cs) and heavy metal concentrations (As, Mn, Fe, Cr, Ni, Zn, Cu and Pb) in four of the most common fish species: Engraulis encrasicholus (anchovy), Oncorhynchus mykiss (trout), Trachurus mediterranus (bluefin) and Merlangius merlangus (whiting) samples collected from eight stations in the Black Sea Region of Turkey during 2010. The dose due to consumption of fish by the public was estimated and it was shown that this dose imposes no threat to human healthy. The concentrations of heavy metal are below the daily intake recommended by the international organizations.
[Pubmed: 22225706]
| | 9. |
2012 Jan 18 |
Richness and diversity of helminth communities in the Japanese grenadier anchovy, Coilia nasus, during its anadromous migration in the Yangtze River, China.
Li WX, Zou H, Wu SG, Song R, Wang GT
J Parasitol. 2012 Jan 18; [Epub ahead of print]
Abstract
Abstract To determine the relationship between the species richness, diversity of helminth communities, and the migration distance during upward migration from coast to freshwater, helminth communities in the anadromous fish Coilia nasus were investigated along the coast, the Yangtze Estuary, and 3 localities on the Yangtze River. Six helminth species were found in 224 C. nasus. Changes in salinity usually reduced the survival time of parasites, and thus the number of helminth species and their abundance. Except for the 2 dominant helminths, the acanthocephalan Acanthosentis cheni and the nematode Contracaecum sp., mean abundance of other 4 species of helminths was rather low (< 1.0) during the upward migration in the Yangtze River. Mean abundance of the 2 dominant helminths peaked in the Yangtze Estuary and showed no obvious decrease among the 3 localities on the Yangtze River. Mean species richness, Brillouin's index, and Shannon index were also highest in the estuary (with 1.93 ± 0.88, 0.28 ± 0.25, and 0.37 ± 0.34, respectively) and did not exhibit marked decline at the 3 localities on the Yangtze River. A significant negative correlation was not seen between the similarity and the geographical distance (R = -0.5104, P = 0.1317). The strong salinity tolerance of intestinal helminths, relatively brief stay in the Yangtze River, and a large amount of feeding on small fish and shrimp when commencing spawning migration perhaps were responsible for the results.
[Pubmed: 22257179]
| | 10. |
2012 Feb |
Sociocultural and Dietary Practices Among Malay Subjects in the North-Eastern Region of Peninsular Malaysia: A Region of Low Prevalence of Helicobacter pylori Infection.
Lee YY, Ismail AW, Mustaffa N, Musa KI, Majid NA, Choo KE, Mahendra Raj S, Derakhshan MH, Malaty HM, Graham DY
Helicobacter. 2012 Feb;17(1):54-61.
Abstract
Background and Aim: The prevalence of Helicobacter pylori infection is exceptionally low among the Malays in the north-eastern region of Peninsular Malaysia. The reasons are unknown. Our aim was to compare environmental factors that differed in relation to H. pylori prevalence among Malays born and residing in Kelantan. Methods: A case-control study was conducted among Malays in Kelantan who underwent upper endoscopy between 2000 and 2008. Helicobacter pylori status was determined by gastric histology. Sociocultural and dietary factors were assessed using a validated investigator-directed questionnaire administered after 2008, and the data were analyzed using logistic regression analysis. Results: The study group consisted of 161 subjects (79 H. pylori positive and 82 controls). Univariable analysis identified five poor sanitary practices associated with an increased prevalence of H. pylori infection: use of well water, use of pit latrine, less frequent boiling of drinking water, and infrequent hand wash practice after toilet use and before meals. Multivariable logistic regression analysis identified three variables inversely associated with H. pylori infection: frequent consumption of tea (OR: 0.023, 95% CI: 0.01-0.07), frequent use of "budu" or local anchovy sauce (OR: 0.09, 95% CI: 0.1-0.7), and frequent use of "pegaga" or centenella asiatica (OR: 0.25, 95% CI: 0.1-0.65). Conclusions: Under the assumption that sanitary, sociocultural, and dietary habits have not changed over the years, we can conclude that an increased risk of H. pylori was associated with unsanitary practices whereas protection was associated with consumption of tea and locally produced foods, "pegaga" and "budu." These dietary factors are candidates for future study on the effects on H. pylori transmission.
[Pubmed: 22221617]
| | 11. |
2012 Feb 07 |
Descriptions of digeneans from Sardina pilchardus (Walbaum) (Clupeidae) off the Algerian coast of the western Mediterranean, with a complete list of its helminth parasites.
Marzoug D, Boutiba Z, Gibson DI, Pérez-Del-Olmo A, Kostadinova A
Syst. Parasitol. 2012 Mar;81(3):169-86. Epub 2012 Feb 07.
Abstract
Five species of digeneans parasitic in the pilchard Sardina pilchardus (Walbaum), a little studied host, from off the Algerian coast of the western Mediterranean are redescribed. These are Parahemiurus merus (Linton, 1910) Manter, 1940, Aphanurus stossichii (Monticelli, 1891) Looss, 1907, Aphanurus virgula Looss, 1907, Lecithaster confusus Odhner, 1905 and Pronoprymna ventricosa (Rudolphi, 1819) Poche, 1926. One of these, A. virgula, is a new record for this host. One other digenean, Hemiurus luehei Odhner, 1905, was also recorded from this host. A complete checklist of the helminth parasites of S. pilchardus throughout its distributional range, comprising 104 host-parasite records of 39 taxa, is presented.
[Pubmed: 22311267]
| | 12. |
2012 Feb 11 |
Proximate and Fatty Acid Composition of Some Commercially Important Fish Species from the Sinop Region of the Black Sea.
Kocatepe D, Turan H
Lipids. 2012 Feb 11; [Epub ahead of print]
Abstract
The proximate and fatty acid compositions of the commercially important fish species (Engraulis encrasicolus, Alosa alosa, Belone belone, Scorpaena porcus, Pomatomus saltatrix, Mullus barbatus) from the Sinop region of the Black Sea were examined. The fat contents ranged from 1.26% (for scorpion fish) to 18.12% (for shad). The protein contents were min 14.54% (for red mullet) and maximum 20.26% (for belone). The fatty acid compositions of the fish ranged from 27.83 to 35.91% for saturated fatty acids, 19.50-33.80% for monounsaturated fatty acids and 15.25-40.02% for polyunsaturated fatty acids. Among the saturated fatty acids, palmitic acid (16:0) (17.75-22.20%) was the dominant fatty acid for all the fish species. As a second saturated fatty acid, myristic acid (14:0) was observed in four of the fish species and its content ranged from 4.72 to 7.31%. Whereas, for the other two fish species, the second saturated fatty acid was stearic acid (18:0) ranging between 4.54 and 10.64%. Among the monounsaturated fatty acids, those occurring in the highest proportions were oleic acid (18:1n-9c) (11.67-22.45%) and palmitoleic acid (16:1) (4.50-9.40%). Docosahexaenoic acid (22:6n-3) (5.41-28.52%), eicosapentaenoic acid (20:5n-3) (4.68-11.06) and linoleic acid (18:2n-6) (1.38-3.49%) were dominant polyunsaturated fatty acids, respectively. All the species, in particular the belone, the anchovy and the shad had high levels of the n-3 series.
[Pubmed: 22322400]
| | 13. |
2012 Feb 27 |
Characterization of phospholipid molecular species in the edible parts of bony fish and shellfish.
Boselli E, Pacetti D, Lucci P, Frega NG
J Agric Food Chem. 2012 Feb 27; [Epub ahead of print]
Abstract
The phospholipid molecular species of freshwater (pangasius, Nile perch, trout), marine fish fillets (horse mackerel, European hake, common sole, European anchovy, European pilchard, Atlantic mackerel) and the edible muscle foot of bivalves (clam, mussel, oyster) commonly available in the Italian market during spring and summer was characterized by means of normal-phase high performance liquid chromatography coupled on-line with positive electrospray ionization ion-trap tandem mass spectrometry. From principal component analysis (PCA) it was observed that the total fatty acid profile was not suitable to differentiate among the shellfish genera. The fatty acid molecular combinations of phosphatidylcholine, the main phospholipid class, as well as phosphatidylinositol and phosphatidylethanolamine allowed for the differentiation of shellfish from the bony fishes. Phosphatidylserine and phosphatidylethanolamine plasmalogen profile allowed for the discrimination of each bony fish or shellfish genus, since PS and pPE classes included a large number of fatty acid combinations which were specific for a fish genus or group.
[Pubmed: 22369175]
| | 14. |
2012 Feb 2 |
Molecular phylogenetics reveals a pattern of biome conservatism in New World anchovies (family Engraulidae).
Bloom DD, Lovejoy NR
J Evol Biol. 2012 Feb 2; [Epub ahead of print]
Abstract
Evolutionary transitions between marine and freshwater biomes are relatively rare events, yielding a widespread pattern of biome conservatism among aquatic organisms. We investigated biome transitions in anchovies (Engraulidae), a globally distributed clade of economically important fishes. Most anchovy species are near-shore marine fishes, but several exclusively freshwater species are known from tropical rivers of South America and were previously thought to be the product of six or more independent freshwater invasions. We generated a comprehensive molecular phylogeny for Engraulidae, including representatives from 15 of 17 currently recognized genera. Our data support previous hypotheses of higher-level relationships within Engraulidae, but show that most New World genera are not monophyletic and in need of revision. Ancestral character reconstruction reveals that New World freshwater anchovies are the product of a single marine to freshwater transition, supporting a pattern of biome conservatism. We argue that competition is the principal mechanism that regulates aquatic biome transitions on a continental scale.
[Pubmed: 22300535]
| | 15. |
2012 Feb 2 |
Molecular identification of Anisakis spp. from fishes collected in the Tyrrhenian Sea (NW Mediterranean).
Cavallero S, Ligas A, Bruschi F, D'Amelio S
Vet Parasitol. 2012 Feb 2; [Epub ahead of print]
Abstract
The accurate identification of anisakid nematodes at any life cycle stage is important both to deepen the knowledge on their taxonomy, ecology, epidemiology and for diagnosis and control, as larval stages cause a clinical disease in humans known as anisakidosis. With the aim to investigate the presence of anisakid larvae, specimens of horse mackerel, Trachurus trachurus (Linnaeus, 1758), silver scabbardfish, Lepidopus caudatus (Euphrasen, 1788), European anchovy, Engraulis encrasicolus (Linnaeus, 1758) and opah fish, Lampris guttatus (Brunnich, 1788), were collected by trawling at depths ranging from 50 to 400m. A molecular approach based on restriction profiles obtained after digestion of the nuclear ribosomal ITS region was used to identify Anisakis spp. larvae recovered in fish samples. Restriction profiles showed three banding patterns, corresponding to Anisakis pegreffii, Anisakis physeteris and to heterozygote pattern between A. pegreffii and Anisakis simplex s.s. Specimens showing the heterozygote restriction pattern were also analyzed by sequencing of the entire ITS region, to confirm the heterozygote status.
[Pubmed: 22360842]
| | 16. |
2011 Dec 19 |
Speciation analysis of mercury in natural water and fish samples by using capillary electrophoresis-inductively coupled plasma mass spectrometry.
Zhao Y, Zheng J, Fang L, Lin Q, Wu Y, Xue Z, Fu F
Talanta. 2012 Jan 30;89:280-5. Epub 2011 Dec 19.
Abstract
A environment-friendly microwave-assisted extraction used to extract trace mercury compounds from fish samples, and a ultra-sensitive method for the analysis of Hg(II), methylmercury (MeHg) and ethylmercury (EtHg) by using capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) were described in this study. The extraction method is environment-friendly, simple, effective, and can be used to extract trace mercury compounds in fish samples with a satisfied recovery within several minutes. The CE-ICP-MS analytical method has a detection limit as lower as 0.021-0.032 ng Hg/mL for MeHg, EtHg and Hg(II), and can be used to determined ultratrace MeHg, EtHg and Hg(II) in natural water and fish samples directly without any preconcentration. With the help of the above methods, we have successfully determined MeHg, EtHg and Hg(II) in dried fish (Tapertail anchovy) muscle and natural water within 25 min with a RSD (relative standard deviation, n=6) <5% and a recovery of 94-103%. Our results showed that dried muscle of T. anchovy contained only one species of mercury, MeHg, indicating that MeHg is easier to be accumulated by aquatic organisms.
[Pubmed: 22284493]
| | 17. |
2012 |
Beneficial effect of teleost fish bone Peptide as calcium supplements for bone mineralization.
Kim SK, Jung WK
Adv. Food Nutr. Res. 2012;65:287-95.
Abstract
A most common and trusted source of Ca is milk or other dairy products. However, some oriental people do not drink milk due to lactose indigestion and intolerance, which make them allergic to milk. There have been many studies on alternative calcium-rich diet or Ca supplements. Among them, teleost fish like anchovy and mola, which are commonly consumed in Asian countries, could be an important Ca dietary supplement, especially in population groups with low intakes of milk and dairy products. In this chapter, we summarize beneficial effects of teleost fish bone peptide (FBP) for Ca bioavailability and bone mineralization, based on our researches.
[Pubmed: 22361195]
| | 18. |
2012 |
Characterization of Selenium Species in Extract from Niboshi (a Processed Japanese Anchovy).
Yoshida S, Haratake M, Fuchigami T, Nakayama M
Chem. Pharm. Bull. 2012;60(3):348-53.
Abstract
Fish are selenium rich foodstuffs and a major selenium source for the Japanese population. Niboshi is processed from Japanese anchovy (Engraulis japonicus) and commonly used to prepare soup stock for Japanese dishes. In this study, we characterized selenium species in the Niboshi extract by ultrafiltration, ion-exchange chromatography and mass spectrometry. Selenium species in the Niboshi were more extractable by polar solvents (water and ethanol) than an apolar one (hexane) along with amino acids and proteinous species. Selenium in the water-extract from the Niboshi was mostly ascribed to organoselenium compounds with a molecular mass less than 5 kDa. Although selenoamino acids and selenoproteins and their fragments were involved in the extract, a large portion of the selenium species appeared to be low-molecular-mass organoselenium compounds other than selenoamino acids and their derivatives. Ion-exchange chromatographic separations revealed that most of the selenium species in the extract possess anionic and/or amphoteric characteristics. One of these selenium species from the Niboshi extract was detected at m/z 577 for (80)Se by mass spectrometry subsequent to ion-pair extraction.
[Pubmed: 22382415]
| | 19. |
2012 Mar 7 |
Genetic structuring of European anchovy (Engraulis encrasicolus) populations through mitochondrial DNA sequences.
Keskin E, Atar HH
Mitochondrial DNA. 2012 Mar 7; [Epub ahead of print]
Abstract
Mitochondrial DNA sequence variation in 655 bpfragments of the cytochrome oxidase c subunit I gene, known as the DNA barcode, of European anchovy (Engraulis encrasicolus) was evaluated by analyzing 1529 individuals representing 16 populations from the Black Sea, through the Marmara Sea and the Aegean Sea to the Mediterranean Sea. A total of 19 (2.9%) variable sites were found among individuals, and these defined 10 genetically diverged populations with an overall mean distance of 1.2%. The highest nucleotide divergence was found between samples of eastern Mediterranean and northern Aegean (2.2%). Evolutionary history analysis among 16 populations clustered the Mediterranean Sea clades in one main branch and the other clades in another branch. Diverging pattern of the European anchovy populations correlated with geographic dispersion supports the genetic structuring through the Black Sea-Marmara Sea-Aegean Sea-Mediterranean Sea quad.
[Pubmed: 22397375]
| | 20. |
2012 Mar 09 |
Isolation and Characterization of an Antibacterial Peptide Fraction from the Pepsin Hydrolysate of Half-Fin Anchovy (Setipinna taty).
Song R, Wei RB, Luo HY, Wang DF
Molecules. 2012;17(3):2980-91. Epub 2012 Mar 09.
Abstract
Enzymatic proteolysis of food proteins is considered a promising method to generate antibacterial peptides. The objective of the present study was to isolate and characterize peptide fraction from the pepsin hydrolysate of half-fin anchovy (Setipinna taty) with antibacterial activity against Escherichia coli. The most active peptide fraction HAHp2-3-I was isolated by a series of chromatographic methods, including Sephadex G-25 chromatography, reverse high-performance liquid chromatography (RP-HPLC) and Source 5RPC ST. Peptides identification of HAHp2-3-I was carried out using UPLC-LTQ-Orbitrap mass spectrometer. HAHp2-3-I contained five cationic peptides (MLTTPPHAKYVLQW, SHAATKAPPKNGNY, PTAGVANALQHA, QLGTHSAQPVPF and VNVDERWRKL) and three anionic peptides (LATVSVGAVELCY, NPEFLASGDHLDNLQ and PEVVYECLHW). Prediction of peptide secondary structure indicated that these anionic peptides should have extended strand and random coil structures, whereas cationic peptides PTAGVANALQHA and VNVDERWRKL could form alpha helixes. In addition, results of scanning electron microscopy (SEM) revealed that treatment by HAHp2-3-I could cause the morphological changes of E. coli and destruction of the cell integrity via irreversible membrane damage. The results could provide information for investigating the antibacterial model of antibacterial peptides derived from fish protein hydrolysates.
[Pubmed: 22406902]
| | 21. |
2012 Mar 23 |
Patterns of Diversity in Soft-Bodied Meiofauna: Dispersal Ability and Body Size Matter
Curini-Galletti, Artois, Delogu, De Smet, Fontaneto, Jondelius, Leasi, Martínez, Meyer-Wachsmuth, Nilsson, Tongiorgi, Worsaae, Todaro
PLoS One 2012 Mar 23;7(3). published online before print
Abstract
Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups.
[Pubmed: 22457790]
| | 22. |
2012 Mar 15 |
The application of an age-structured model to the north Aegean anchovy fishery: An evaluation of different management measures.
Politikos DV, Tzanetis DE, Nikolopoulos CV, Maravelias CD
Math Biosci. 2012 Mar 15; [Epub ahead of print]
Abstract
The objective of this paper is the integration of existing biological and fishery knowledge of anchovy into a unified modelling framework in order to advance our understanding of species' population dynamics under different fishing strategies. The model simulates the anchovy biomass by combining an age-specific growth equation and a continuous age-structured population model based on the McKendrick-Von Foerster equation. Model predictions were compared to the biomass estimates and annual catches during the period 2003-2008. The present work provided direct evidence for the significance of the prespawning period as a critical life period for the management of anchovy stock in the Aegean Sea. It was found that the introduction of additional management measures could increase the profits in the long run for the fishery. However, for these to become apparent they will require a minimum of four years. Results also indicated that the reduction of fishing mortality directed at the spawning stock (recruitment overfishing) and the selective harvesting of younger individuals may be a plausible means of increasing stock's total anchovy biomass. Finally, as a criterion of long-term population survival, we have considered the mathematical notation of persistence. The numerical criteria of persistence in the present model indicated that the anchovy population could be considered viable.
[Pubmed: 22426444]
| | 23. |
2012 Mar 9 |
Efficient expression and purification of recombinant glutaminase from Bacillus licheniformis (GlsA) in Escherichia coli.
Sinsuwan S, Yongsawatdigul J, Chumseng S, Yamabhai M
Protein Expr Purif. 2012 Mar 9;83(1):52-58. Epub 2012 Mar 9.
Abstract
Glutaminase or l-glutamine aminohydrolase (EC 3.5.1.2) is an enzyme that catalyzes the formation of glutamic acid and ammonium ion from glutamine. This enzyme functions in cellular metabolism of every organism by supplying nitrogen required for the biosynthesis of a variety of metabolic intermediates, while glutamic acid plays a role in both sensory and nutritional properties of food. So far there have been only a few reports on cloning, expression and characterization of purified glutaminases. Microbial glutaminases are enzymes with emerging potential in both the food and the pharmaceutical industries. In this research a recombinant glutaminase from Bacillus licheniformis (GlsA) was expressed in Escherichia coli, under the control of a ptac promoter. The recombinant enzyme was tagged with decahistidine tag at its C-terminus and could be conveniently purified by one-step immobilized metal affinity chromatography (IMAC) to apparent homogeneity. The enzyme could be induced for efficient expression with IPTG, yielding approximately 26,000units from 1-l shake flask cultures. The enzyme was stable at 30°C and pH 7.5 for up to 6h, and could be used efficiently to increase glutamic acid content when protein hydrolysates from soy and anchovy were used as substrates. The study demonstrates an efficient expression system for the production and purification of bacterial glutaminase. In addition, its potential application for bioconversion of glutamine to flavor-enhancing glutamic acid has been demonstrated.
[Pubmed: 22433447]
| | 24. |
2012 Apr 02 |
All-enzymatic HPLC method for determination of individual and total contents of vitamin B(6) in foods.
Thi Viet Do H, Ide Y, Mugo AN, Yagi T
Food Nutr Res. 2012;56. Epub 2012 Apr 02.
Abstract
There is a need for a reliable and accurate method for quantification of each of the seven individual vitamin B(6) compounds including pyridoxine-β-glucoside in foods.
[Pubmed: 22481897]
| | 25. |
2012 Apr 11 |
Distribution and Habitat Associations of Billfish and Swordfish Larvae across Mesoscale Features in the Gulf of Mexico.
Rooker JR, Simms JR, Wells RJ, Holt SA, Holt GJ, Graves JE, Furey NB
PLoS ONE. 2012;7(4):e34180. Epub 2012 Apr 11.
Abstract
Ichthyoplankton surveys were conducted in surface waters of the northern Gulf of Mexico (NGoM) over a three-year period (2006-2008) to determine the relative value of this region as early life habitat of sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida), and swordfish (Xiphias gladius). Sailfish were the dominant billfish collected in summer surveys, and larvae were present at 37.5% of the stations sampled. Blue marlin and white marlin larvae were present at 25.0% and 4.6% of the stations sampled, respectively, while swordfish occurred at 17.2% of the stations. Areas of peak production were detected and maximum density estimates for sailfish (22.09 larvae 1000 m(-2)) were significantly higher than the three other species: blue marlin (9.62 larvae 1000 m(-2)), white marlin (5.44 larvae 1000 m(-2)), and swordfish (4.67 larvae 1000 m(-2)). The distribution and abundance of billfish and swordfish larvae varied spatially and temporally, and several environmental variables (sea surface temperature, salinity, sea surface height, distance to the Loop Current, current velocity, water depth, and Sargassum biomass) were deemed to be influential variables in generalized additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and swordfish larvae, with densities typically higher in frontal zones or areas proximal to the Loop Current. Habitat suitability of all four species was strongly linked to physicochemical attributes of the water masses they inhabited, and observed abundance was higher in slope waters with lower sea surface temperature and higher salinity. Our results highlight the value of the NGoM as early life habitat of billfishes and swordfish, and represent valuable baseline data for evaluating anthropogenic effects (i.e., Deepwater Horizon oil spill) on the Atlantic billfish and swordfish populations.
[Pubmed: 22509277]
| | 26. |
2012 Apr 19 |
Effect of Sub-Lethal Exposure to Ultraviolet Radiation on the Escape Performance of Atlantic Cod Larvae (Gadus morhua)
Fukunishi, Browman, Durif, Bjelland, Skiftesvik
PLoS One 2012 Apr 19;7(4). published online before print
Abstract
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%, Control: 63%). No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%, Control: 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.
[Pubmed: 22536406]
| | 27. |
2012 Apr 27 |
Land Cover and Rainfall Interact to Shape Waterbird Community Composition
Studds, DeLuca, Baker, King, Marra
PLoS One 2012 Apr 27;7(4). published online before print
Abstract
Human land cover can degrade estuaries directly through habitat loss and fragmentation or indirectly through nutrient inputs that reduce water quality. Strong precipitation events are occurring more frequently, causing greater hydrological connectivity between watersheds and estuaries. Nutrient enrichment and dissolved oxygen depletion that occur following these events are known to limit populations of benthic macroinvertebrates and commercially harvested species, but the consequences for top consumers such as birds remain largely unknown. We used non-metric multidimensional scaling (MDS) and structural equation modeling (SEM) to understand how land cover and annual variation in rainfall interact to shape waterbird community composition in Chesapeake Bay, USA. The MDS ordination indicated that urban subestuaries shifted from a mixed generalist-specialist community in 2002, a year of severe drought, to generalist-dominated community in 2003, of year of high rainfall. The SEM revealed that this change was concurrent with a sixfold increase in nitrate-N concentration in subestuaries. In the drought year of 2002, waterbird community composition depended only on the direct effect of urban development in watersheds. In the wet year of 2003, community composition depended both on this direct effect and on indirect effects associated with high nitrate-N inputs to northern parts of the Bay, particularly in urban subestuaries. Our findings suggest that increased runoff during periods of high rainfall can depress water quality enough to alter the composition of estuarine waterbird communities, and that this effect is compounded in subestuaries dominated by urban development. Estuarine restoration programs often chart progress by monitoring stressors and indicators, but rarely assess multivariate relationships among them. Estuarine management planning could be improved by tracking the structure of relationships among land cover, water quality, and waterbirds. Unraveling these complex relationships may help managers identify and mitigate ecological thresholds that occur with increasing human land cover.
[Pubmed: 22558286]
| | 28. |
2012 Apr 27 |
Molecular Systematic of Three Species of Oithona (Copepoda, Cyclopoida) from the Atlantic Ocean: Comparative Analysis Using 28S rDNA
Cepeda, Blanco-Bercial, Bucklin, Berón, Viñas
PLoS One 2012 Apr 27;7(4). published online before print
Abstract
Species of Oithona (Copepoda, Cyclopoida) are highly abundant, ecologically important, and widely distributed throughout the world oceans. Although there are valid and detailed descriptions of the species, routine species identifications remain challenging due to their small size, subtle morphological diagnostic traits, and the description of geographic forms or varieties. This study examined three species of Oithona (O. similis, O. atlantica and O. nana) occurring in the Argentine sector of the South Atlantic Ocean based on DNA sequence variation of a 575 base-pair region of 28S rDNA, with comparative analysis of these species from other North and South Atlantic regions. DNA sequence variation clearly resolved and discriminated the species, and revealed low levels of intraspecific variation among North and South Atlantic populations of each species. The 28S rDNA region was thus shown to provide an accurate and reliable means of identifying the species throughout the sampled domain. Analysis of 28S rDNA variation for additional species collected throughout the global ocean will be useful to accurately characterize biogeographical distributions of the species and to examine phylogenetic relationships among them.
[Pubmed: 22558245]
| | 29. |
2012 Apr 25 |
A Ranking System for Reference Libraries of DNA Barcodes: Application to Marine Fish Species from Portugal
Costa, Landi, Martins, Costa, Costa, Carneiro, Alves, Steinke, Carvalho
PLoS One 2012 Apr 25;7(4). published online before print
Abstract
The increasing availability of reference libraries of DNA barcodes (RLDB) offers the opportunity to the screen the level of consistency in DNA barcode data among libraries, in order to detect possible disagreements generated from taxonomic uncertainty or operational shortcomings. We propose a ranking system to attribute a confidence level to species identifications associated with DNA barcode records from a RLDB. Here we apply the proposed ranking system to a newly generated RLDB for marine fish of Portugal.
[Pubmed: 22558244]
| | 30. |
2012 Apr 25 |
Model-Derived Dispersal Pathways from Multiple Source Populations Explain Variability of Invertebrate Larval Supply
Domingues, Nolasco, Dubert, Queiroga
PLoS One 2012 Apr 25;7(4). published online before print
Abstract
Predicting the spatial and temporal patterns of marine larval dispersal and supply is a challenging task due to the small size of the larvae and the variability of oceanographic processes. Addressing this problem requires the use of novel approaches capable of capturing the inherent variability in the mechanisms involved.
[Pubmed: 22558225]
| | 31. |
2012 Apr 27 |
Disparity Changes in 370 Ma Devonian Fossils: The Signature of Ecological Dynamics?
Girard, Renaud
PLoS One 2012 Apr 27;7(4). published online before print
Abstract
Early periods in Earth's history have seen a progressive increase in complexity of the ecosystems, but also dramatic crises decimating the biosphere. Such patterns are usually considered as large-scale changes among supra-specific groups, including morphological novelties, radiation, and extinctions. Nevertheless, in the same time, each species evolved by the way of micro-evolutionary processes, extended over millions of years into the evolution of lineages. How these two evolutionary scales interacted is a challenging issue because this requires bridging a gap between scales of observation and processes. The present study aims at transferring a typical macro-evolutionary approach, namely disparity analysis, to the study of fine-scale evolutionary variations in order to decipher what processes actually drove the dynamics of diversity at a micro-evolutionary level. The Late Frasnian to Late Famennian period was selected because it is punctuated by two major macro-evolutionary crises, as well as a progressive diversification of marine ecosystem. Disparity was estimated through this period on conodonts, tooth-like fossil remains of small eel-like predators that were part of the nektonic fauna. The study was focused on the emblematic genus of the period, Palmatolepis. Strikingly, both crises affected an already impoverished Palmatolepis disparity, increasing risks of random extinction. The major disparity signal rather emerged as a cycle of increase and decrease in disparity during the inter-crises period. The diversification shortly followed the first crisis and might correspond to an opportunistic occupation of empty ecological niche. The subsequent oriented shrinking in the morphospace occupation suggests that the ecological space available to Palmatolepis decreased through time, due to a combination of factors: deteriorating climate, expansion of competitors and predators. Disparity changes of Palmatolepis thus reflect changes in the structure of the ecological space itself, which was prone to evolve during this ancient period where modern ecosystems were progressively shaped.
[Pubmed: 22558396]
| | 32. |
2012 Apr 13 |
The Effects of Spatially Heterogeneous Prey Distributions on Detection Patterns in Foraging Seabirds
Miramontes, Boyer, Bartumeus
PLoS One 2012 Apr 13;7(4). published online before print
Abstract
Many attempts to relate animal foraging patterns to landscape heterogeneity are focused on the analysis of foragers movements. Resource detection patterns in space and time are not commonly studied, yet they are tightly coupled to landscape properties and add relevant information on foraging behavior. By exploring simple foraging models in unpredictable environments we show that the distribution of intervals between detected prey (detection statistics) is mostly determined by the spatial structure of the prey field and essentially distinct from predator displacement statistics. Detections are expected to be Poissonian in uniform random environments for markedly different foraging movements (e.g. Lévy and ballistic). This prediction is supported by data on the time intervals between diving events on short-range foraging seabirds such as the thick-billed murre (Uria lomvia). However, Poissonian detection statistics is not observed in long-range seabirds such as the wandering albatross (Diomedea exulans) due to the fractal nature of the prey field, covering a wide range of spatial scales. For this scenario, models of fractal prey fields induce non-Poissonian patterns of detection in good agreement with two albatross data sets. We find that the specific shape of the distribution of time intervals between prey detection is mainly driven by meso and submeso-scale landscape structures and depends little on the forager strategy or behavioral responses.
[Pubmed: 22514629]
| | 33. |
2012 Apr 26 |
An Experimental Field Study of Delayed Density Dependence in Natural Populations of Aedes albopictus
Walsh, Bradley, Apperson, Gould
PLoS One 2012 Apr 26;7(4). published online before print
Abstract
Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.
[Pubmed: 22563428]
| | 34. |
2012 May 10 |
Protecting persistent dynamic oceanographic features: transboundary conservation efforts are needed for the critically endangered balearic shearwater.
Louzao M, Delord K, García D, Boué A, Weimerskirch H
PLoS ONE. 2012;7(5):e35728. Epub 2012 May 10.
Abstract
The protection of key areas for biodiversity at sea is not as widespread as on land and research investment is necessary to identify biodiversity hotspots in the open ocean. Spatially explicit conservation measures such as the creation of representative networks of marine protected areas (MPAs) is a critical step towards the conservation and management of marine ecosystems, as well as to improve public awareness. Conservation efforts in ecologically rich and threatened ecosystems are specially needed. This is particularly urgent for the Mediterranean marine biodiversity, which includes highly mobile marine vertebrates. Here, we studied the at sea distribution of one of the most endangered Mediterranean seabird, the critically endangered Balearic shearwater Puffinus mauretanicus. Present knowledge, from vessel-based surveys, suggests that this species has a coastal distribution over the productive Iberian shelf in relation to the distribution of their main prey, small pelagic fish. We used miniaturised satellite transmitters to determine the key marine areas of the southern population of Balearic shearwaters breeding on Eivissa and spot the spatial connections between breeding and key marine areas. Our tracking study indicates that Balearic shearwaters do not only forage along the Iberian continental shelf but also in more distant marine areas along the North African coast, in particular W of Algeria, but also NE coast of Morocco. Birds recurrently visit these shelf areas at the end of the breeding season. Species distribution modelling identified chlorophyll a as the most important environmental variable in defining those oceanographic features characterizing their key habitats in the western Mediterranean. We identified persistent oceanographic features across time series available in the study area and discuss our results within the current conservation scenario in relation to the ecology of the species.
[Pubmed: 22590510]
| | 35. |
2012 Apr 20 |
Can Thermoclines Be a Cue to Prey Distribution for Marine Top Predators? A Case Study with Little Penguins
Pelletier, Kato, Chiaradia, Ropert-Coudert
PLoS One 2012 Apr 20;7(4). published online before print
Abstract
The use of top predators as bio-platforms is a modern approach to understanding how physical changes in the environment may influence their foraging success. This study examined if the presence of thermoclines could be a reliable signal of resource availability for a marine top predator, the little penguin (Eudyptula minor). We studied weekly foraging activity of 43 breeding individual penguins equipped with accelerometers. These loggers also recorded water temperature, which we used to detect changes in thermal characteristics of their foraging zone over 5 weeks during the penguin’s guard phase. Data showed the thermocline was detected in the first 3 weeks of the study, which coincided with higher foraging efficiency. When a thermocline was not detected in the last two weeks, foraging efficiency decreased as well. We suggest that thermoclines can represent temporary markers of enhanced food availability for this top-predator to which they must optimally adjust their breeding cycle.
[Pubmed: 22536314]
| | 36. |
2012 May 8 |
Fish Is Food - The FAO’s Fish Price Index
Tveterås, Asche, Bellemare, Smith, Guttormsen, Lem, Lien, Vannuccini
PLoS One 2012 May 8;7(5). published online before print
Abstract
World food prices hit an all-time high in February 2011 and are still almost two and a half times those of 2000. Although three billion people worldwide use seafood as a key source of animal protein, the Food and Agriculture Organization (FAO) of the United Nations–which compiles prices for other major food categories–has not tracked seafood prices. We fill this gap by developing an index of global seafood prices that can help to understand food crises and may assist in averting them. The fish price index (FPI) relies on trade statistics because seafood is heavily traded internationally, exposing non-traded seafood to price competition from imports and exports. Easily updated trade data can thus proxy for domestic seafood prices that are difficult to observe in many regions and costly to update with global coverage. Calculations of the extent of price competition in different countries support the plausibility of reliance on trade data. Overall, the FPI shows less volatility and fewer price spikes than other food price indices including oils, cereals, and dairy. The FPI generally reflects seafood scarcity, but it can also be separated into indices by production technology, fish species, or region. Splitting FPI into capture fisheries and aquaculture suggests increased scarcity of capture fishery resources in recent years, but also growth in aquaculture that is keeping pace with demand. Regionally, seafood price volatility varies, and some prices are negatively correlated. These patterns hint that regional supply shocks are consequential for seafood prices in spite of the high degree of seafood tradability.
[Pubmed: 22590598]
| | 37. |
2012 May 22 |
Dispersal Routes and Habitat Utilization of Juvenile Atlantic Bluefin Tuna, Thunnus thynnus, Tracked with Mini PSAT and Archival Tags
Galuardi, Lutcavage
PLoS One 2012 May 22;7(5). published online before print
Abstract
Between 2005 and 2009, we deployed 58 miniature pop-up satellite archival tags (PSAT) and 132 implanted archival tags on juvenile Atlantic bluefin tuna (age 2–5) in the northwest Atlantic Ocean. Data returned from these efforts (n = 26 PSATs, 1 archival tag) revealed their dispersal routes, horizontal and vertical movements and habitat utilization. All of the tagged bluefin tuna remained in the northwest Atlantic for the duration observed, and in summer months exhibited core-use of coastal seas extending from Maryland to Cape Cod, MA, (USA) out to the shelf break. Their winter distributions were more spatially disaggregated, ranging south to the South Atlantic Bight, northern Bahamas and Gulf Stream. Vertical habitat patterns showed that juvenile bluefin tuna mainly occupied shallow depths (mean = 5–12 m, sd = 15–23.7 m) and relatively warm water masses in summer (mean = 17.9–20.9°C, sd = 4.2–2.6°C) and had deeper and more variable depth patterns in winter (mean = 41–58 m, sd = 48.9–62.2 m). Our tagging results reveal annual dispersal patterns, behavior and oceanographic associations of juvenile Atlantic bluefin tuna that were only surmised in earlier studies. Fishery independent profiling from electronic tagging also provide spatially and temporally explicit information for evaluating dispersals rates, population structure and fisheries catch patterns.
[Pubmed: 22629461]
| | 38. |
2012 May 16 |
Simultaneous determination of four biogenic and three volatile amines in anchovy by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry.
Romero-González R, Alarcón-Flores MI, Vidal JL, Frenich AG
J. Agric. Food Chem. 2012 May 30;60(21):5324-9. Epub 2012 May 16.
Abstract
A new method has been developed and validated for the simultaneous determination of four biogenic (putrescine, cadaverine, histamine, and tyramine) and three volatile amines (trimethylamine, triethylamine, and tripropylamine) in anchovy. Separation and determination of the selected compounds were carried out by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), using an electrospray ionization source (ESI) in positive ion mode. Chromatographic separation was carried out using an aqueous solution of formic acid (0.1%) and methanol as mobile phase in gradient mode. The method was validated, and mean recoveries were evaluated at three concentration levels (75, 150, and 250 μg/kg), ranging from 70 to 110% at the three levels assayed. Intra- and interday precision, expressed as relative standard deviation (RSD), were lower than 15% and 20%, respectively. Limits of quantitation (LOQs) were 25 μg/kg for all cases, except for that of TMA, which was set at 60 μg/kg. The developed procedure was applied to determine the target compounds in anchovy samples stored during 7 days at 4 °C, observing the increasing in the concentration of these compounds at longer storage time.
[Pubmed: 22559197]
| | 39. |
2012 May 14 |
Molecular identification and population dynamic of Anisakis pegreffii (Nematoda: Anisakidae Dujardin, 1845) isolated from the European anchovy (Engraulis encrasicolus L.) in the Adriatic Sea.
Mladineo I, Simat V, Miletić J, Beck R, Poljak V
Int J Food Microbiol. 2012 May 14; [Epub ahead of print]
Abstract
Anchovy Engraulis encrasicolus (L.) is a coastal pelagic and euryhaline species that represents the only European species of the family Engraulidae, with a widespread distribution. In Croatia, it is marketed fresh, frozen, salted or marinated and mainly exported to Italy and Spain, however Anisakis sp. larval infection is frequently the reason for border rejection. Since it is known that the prevalence and intensity of Anisakis infection varies with fish species, fishing area and season, the aim of our study was to identify Anisakis sp. parasitizing European anchovy and infer its population dynamic through a 2.5-year period. Larvae were found coiled and encysted on the external wall of intestine (94%) and reproductive organs (6%), rarely in fillets. Prevalence was 76.1% (95% confidence limits 74.51-77.56%), mean abundance 6.59 (bootstrap 95% confidence limits 5.81-7.26) and mean intensity 8.67 (bootstrap 95% confidence limits 7.82-9.35). The partial CO2 mitochondrial DNA sequence of the isolated anisakids confirmed clustering of the anchovy parasite within A. pegreffii sister group. Parasite population structure showed plasticity inferred by fishing ground, sampling year and fish gender and size. Compared to anisakid prevalence/abundance in other fish, the European anchovy in the Adriatic Sea represents a moderately high-infected paratenic host, although in the Mediterranean and Atlantic waters, anchovies have shown strikingly lesser values of prevalence. Since this host represents one of the most attractive Mediterranean fisheries products traditionally consumed without thermal preparation that in any case would not disrupt larval antigenicity and prevent human allergies, and given the high prevalence of the anisakid within the host, it is necessary to include anchovy into more firm risk assessment frames in order to develop measures that will support the safe alimentary production and consumption of seafood.
[Pubmed: 22647674]
| | 40. |
2012 May 24 |
Density-Dependent Processes in the Life History of Fishes: Evidence from Laboratory Populations of Zebrafish Danio rerio
Hazlerigg, Lorenzen, Thorbek, Wheeler, Tyler
PLoS One 2012 May 24;7(5). published online before print
Abstract
Population regulation is fundamental to the long-term persistence of populations and their responses to harvesting, habitat modification, and exposure to toxic chemicals. In fish and other organisms with complex life histories, regulation may involve density dependence in different life-stages and vital rates. We studied density dependence in body growth and mortality through the life-cycle of laboratory populations of zebrafish Danio rerio. When feed input was held constant at population-level (leading to resource limitation), body growth was strongly density-dependent in the late juvenile and adult phases of the life-cycle. Density dependence in mortality was strong during the early juvenile phase but declined thereafter and virtually ceased prior to maturation. Provision of feed in proportion to individual requirements (easing resource limitation) removed density dependence in growth and substantially reduced density dependence in mortality, thus indicating that ‘bottom-up’ effects act on growth as well as mortality, but most strongly on growth. Both growth and mortality played an important role in population regulation, with density-dependent growth having the greater impact on population biomass while mortality had the greatest impact on numbers. We demonstrate a clear ontogenic pattern of change in density-dependent processes within populations of a very small (maximum length 5 mm) fish, maintained in constant homogeneous laboratory conditions. The patterns are consistent with those distilled from studies on wild fish populations, indicating the presence of broad ontogenic patterns in density-dependent processes that are invariant to maximum body size and hold in homogeneous laboratory, as well as complex natural environments.
[Pubmed: 22655056]
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