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Sample records for mako isurus oxyrhinchus

  1. Melanomacrophages in three species of free-ranging sharks from the northwestern Atlantic, the blue shark Prionacae glauca (L.), the shortfin mako, Isurus oxyrhinchus Rafinesque, and the thresher, Alopias vulpinus (Bonnaterre).

    Science.gov (United States)

    Borucinska, J D; Kotran, K; Shackett, M; Barker, T

    2009-10-01

    The melanomacrophage aggregates or cells (MMC) are commonly used as biomarkers of exposure to pollution in fish, albeit their numbers and morphological characteristics can be influenced not only by environmental toxins but also by a range of physiological parameters and pathological conditions. Accordingly, before we can use MMC as biomarkers in any fish species, their normal, 'background' characteristics have to be established in apparently healthy fish. The knowledge of MMC in sharks is minimal. The aim of this study was to characterize MMC from 51 free-ranging, large pelagic sharks from the northwestern Atlantic, including shortfin mako, Isurus oxyrhinchus, thresher, Alopias vulpinus and blue shark, Prionacae glauca. The rationale of this study was twofold. First, because, sharks have life histories predisposing them to the accumulation of environmental toxins they constitute good sentinel species of the health of the global marine ecosystem. Second, because many shark populations are in decline or threatened by extinction, we need to expand our understanding of their health status in order to develop appropriate protective measures. All sharks were collected by sports fishing gear between June and August in 2007. Their health condition was assessed by necropsy, morphometrics, and by microscopic examination of gonads, livers, spleens and kidneys. Routine, haematoxylin and eosin and/or Pearl's reagent-stained paraffin embedded sections were studied by light microscopy. Our results provide the first data on the morphometric and morphological characteristics of MMC in viscera of apparently healthy free-ranging sharks from the northwestern Atlantic.

  2. Digestive enzyme activities are higher in the shortfin mako shark, Isurus oxyrinchus, than in ectothermic sharks as a result of visceral endothermy.

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    Newton, Kyle C; Wraith, James; Dickson, Kathryn A

    2015-08-01

    Lamnid sharks are regionally endothermic fishes that maintain visceral temperatures elevated above the ambient water temperature. Visceral endothermy is thought to increase rates of digestion and food processing and allow thermal niche expansion. We tested the hypothesis that, at in vivo temperatures, the endothermic shortfin mako shark, Isurus oxyrinchus, has higher specific activities of three digestive enzymes-gastric pepsin and pancreatic trypsin and lipase-than the thresher shark, Alopias vulpinus, and the blue shark, Prionace glauca, neither of which can maintain elevated visceral temperatures. Homogenized stomach or pancreas tissue obtained from sharks collected by pelagic longline was incubated at both 15 and 25 °C, at saturating substrate concentrations, to quantify tissue enzymatic activity. The mako had significantly higher enzyme activities at 25 °C than did the thresher and blue sharks at 15 °C. This difference was not a simple temperature effect, because at 25 °C the mako had higher trypsin activity than the blue shark and higher activities for all enzymes than the thresher shark. We also hypothesized that the thermal coefficient, or Q 10 value, would be higher for the mako shark than for the thresher and blue sharks because of its more stable visceral temperature. However, the mako and thresher sharks had similar Q 10 values for all enzymes, perhaps because of their closer phylogenetic relationship. The higher in vivo digestive enzyme activities in the mako shark should result in higher rates of food processing and may represent a selective advantage of regional visceral endothermy.

  3. Effects of prolonged entanglement in discarded fishing gear with substantive biofouling on the health and behavior of an adult shortfin mako shark, Isurus oxyrinchus.

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    Wegner, Nicholas C; Cartamil, Daniel P

    2012-02-01

    A mature male shortfin mako, Isurus oxyrinchus, was captured with a three-strand twisted natural fiber rope wrapped around the body causing deep abrasions, scoliosis of the back, and undernourishment. Fifty-two pelagic peduculate barnacles from four species were found fouling on the rope. Assuming larval settlement occurred following entanglement, barnacle growth-rate data suggest the rope had been around the shark for at least 150 days. However, the onset of severe scoliosis (likely linked to the increased constriction of the rope with growth and the added drag induced by biofouling) indicates that this rope may have been in place much longer. Following removal of the rope, a pop-up satellite archival tag was attached to the shark to assess post-release health. The resulting 54 days of tag deployment data show that despite its injuries, the shark survived, and following an initial stress period, exhibited movement patterns characteristic of healthy makos. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Application of Bomb Radiocarbon Chronologies to Shortfin Mako (Isurus oxyrinchus)

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    Ardizzone, D; Cailliet, G M; Natanson, L J; Andrews, A H; Kerr, L A; Brown, T A

    2007-07-16

    There is an ongoing disagreement regarding the aging of the shortfin mako due to a difference of interpretation in the periodic deposition of vertebral growth band pairs, especially for the larger size classes. Using analysis of length-month information, tagging data, and length-frequency analysis, concluded that two band pairs were formed in the vertebral centrum every year (biannual band-pair interpretation). Cailliet et al. (1983), however, presented growth parameters based on the common assumption that one band pair forms annually (annual band-pair interpretation). Therefore, growth rates obtained by Pratt & Casey (1983) were twice that of Cailliet et al. (1983) and could lead to age discrepancies of about 15 years for maximum estimated ages on the order of 30 from the annual band-pair interpretation. Serious consequences in the population dynamics could occur for this species if inputs are based on an invalid age interpretation. The latest Fishery Management Plan (FMP) for Highly Migratory Species (HMS), for example, adopted the biannual band pair deposition hypothesis because it apparently fit the observed growth patterns best (Pacific Fishery Management Council 2003). However, the ongoing uncertainty about the aging of the shortfin mako was acknowledged and it was recommended that an endeavor to resolve this issue be made. Since 1983, five additional studies on the age and growth of the shortfin mako have been conducted (Chan 2001, Campana et al. 2002, Hsu 2003, Ribot-Carballal et al. 2005, Bishop et al. 2006). Using Marginal Increment Ratio (MIR), Hsu (2003) indicated the formation of annual translucent bands from July to September in western North Pacific Ocean shortfin makos. Using Marginal Increment Analysis (MIA) Ribot-Carballal et al. (2005) supported the annual band-pair interpretation for 109 shortfin makos collected in the eastern Pacific Ocean. Although the study provided support for annual band-pair deposition, no statistical test was performed

  5. Water-tunnel studies of heat balance in swimming mako sharks.

    Science.gov (United States)

    Bernal, D; Sepulveda, C; Graham, J B

    2001-12-01

    The mako shark (Isurus oxyrinchus) has specialized vascular networks (retia mirabilia) forming counter-current heat exchangers that allow metabolic heat retention in certain regions of the body, including the aerobic, locomotor red muscle and the viscera. Red muscle, white muscle and stomach temperatures were measured in juvenile (5-13.6 kg) makos swimming steadily in a water tunnel and exposed to stepwise square-wave changes in ambient temperature (T(a)) to estimate the rates of heat transfer and to determine their capacity for the activity-independent control of heat balance. The rates of heat gain of red muscle during warming were significantly higher than the rates of heat loss during cooling, and neither the magnitude of the change in T(a) nor the direction of change in T(a) had a significant effect on red muscle latency time. Our findings for mako red muscle are similar to those recorded for tunas and suggest modulation of retial heat-exchange efficiency as the underlying mechanism controlling heat balance. However, the red muscle temperatures measured in swimming makos (0.3-3 degrees C above T(a)) are cooler than those measured previously in larger decked makos. Also, the finding of non-stable stomach temperatures contrasts with the predicted independence from T(a) recorded in telemetry studies of mako and white sharks. Our studies on live makos provide new evidence that, in addition to the unique convergent morphological properties between makos and tunas, there is a strong functional similarity in the mechanisms used to regulate heat transfer.

  6. Age, Growth and Spatial Distribution of the Life Stages of the Shortfin Mako, Isurus oxyrinchus (Rafinesque, 1810) Caught in the Western and Central Atlantic.

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    Barreto, Rodrigo R; de Farias, Wialla K T; Andrade, Humber; Santana, Francisco M; Lessa, Rosangela

    2016-01-01

    The shortfin mako (Isurus oxyrinchus) is a highly migratory pelagic shark that preferentially inhabits oceanic regions in practically all oceans. The wide distribution range of this species renders it susceptible to coastal and oceanic fishing operations. The International Union for Conservation of Nature (IUCN) and the International Commission for the Conservation of Atlantic Tunas (ICCAT) consider this species to be highly vulnerable, especially due to its biological parameters, which are different from those of other sharks that occupy the same niche (e.g., Prionace glauca). Consequently, considerable declines in abundance have been detected over various parts of its range, most of which are linked to oceanic longline fishing. The species has conflicting life history parameters in studies conducted in the last 30 years, especially with regard to age and growth. The main discrepancies regard the interpretation of the periodicity of the deposition of band pairs (BPs) on vertebrae and the possibility of ontogenetic variations in growth. Shortfin mako sharks (n = 1325) were sampled by onboard observers of the Brazilian chartered pelagic longline fleet based in northeast Brazil from 2005 to 2011. Lengths were 79 to 250 and 73 to 296 cm (fork length, FL) for males and females, respectively, with a statistically significant difference in size between sexes and differences in the proportion of individuals in each size class. The onboard observers collected a subsample of vertebrae (n = 467), only 234 of which were suitable for analyses. Reliability between readings was satisfactory. However, it was not possible to validate periodicity in the formation of age bands in the sample. Thus, the von Bertalanffy growth function was used to calculate growth rates for the species through the interpretation of BPs in different scenarios: one BP per year (s1), two BPs per year (s2) and two BPs per year until five years of life (s3). Growth parameters varied for both females (Linf

  7. Structural studies of haemoglobin from pisces species shortfin mako shark (Isurus oxyrinchus) at 1.9 Å resolution

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    Ramesh, Pandian, E-mail: prms23@gmail.com [Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 440-746 (Korea, Republic of); University of Madras, Maraimalai Campus (Guindy), Chennai 600 025 (India); Sundaresan, S. S.; Sathya Moorthy, Pon.; Balasubramanian, M.; Ponnuswamy, M. N. [University of Madras, Maraimalai Campus (Guindy), Chennai 600 025 (India)

    2013-11-01

    Shortfin mako shark haemoglobin adopts an unliganded deoxy T state conformation, which is shown from the quaternary structural features, interface interactions and heme binding sites of different subunits of haemoglobin with high-resolution X-ray data. Haemoglobin (Hb) is a tetrameric iron-containing protein that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Pisces are the advanced aquatic vertebrates capable of surviving at wide depth ranges. The shortfin mako shark (SMS) is the pelagic, largest, fastest and most sophisticated species of the shark kingdom with well developed eyes. Mostly the pisces species are cold blooded in nature. Distinctly, the SMSs are warm-blooded animals with an advanced circulatory system. SMSs are capable of maintaining elevated muscle temperatures up to 33 K above the ambient water temperatures at a depth of 150–500 m. SMSs have a diverged air-breathing mechanism compared with other vertebrates. The haemoglobin molecule consists of four polypeptide chains, namely two α chains, each with 140 amino acids and two β chains each having 136 amino acids. The SMS Hb was found to crystallize in monoclinic space group P2{sub 1} using the hanging-drop vapour-diffusion method at room temperature. The crystal packing parameters for the SMS Hb structure contain one whole biological molecule in the asymmetric unit with a solvent content of 47%. The SMS Hb quaternary structural features interface–interface interactions and heme binding sites are discussed with different state Hbs and the results reveal that SMS Hb adopts an unliganded deoxy T state conformation.

  8. Structural studies of haemoglobin from pisces species shortfin mako shark (Isurus oxyrinchus) at 1.9 Å resolution

    International Nuclear Information System (INIS)

    Ramesh, Pandian; Sundaresan, S. S.; Sathya Moorthy, Pon.; Balasubramanian, M.; Ponnuswamy, M. N.

    2013-01-01

    Shortfin mako shark haemoglobin adopts an unliganded deoxy T state conformation, which is shown from the quaternary structural features, interface interactions and heme binding sites of different subunits of haemoglobin with high-resolution X-ray data. Haemoglobin (Hb) is a tetrameric iron-containing protein that carries oxygen from the lungs to tissues and carbon dioxide from tissues back to the lungs. Pisces are the advanced aquatic vertebrates capable of surviving at wide depth ranges. The shortfin mako shark (SMS) is the pelagic, largest, fastest and most sophisticated species of the shark kingdom with well developed eyes. Mostly the pisces species are cold blooded in nature. Distinctly, the SMSs are warm-blooded animals with an advanced circulatory system. SMSs are capable of maintaining elevated muscle temperatures up to 33 K above the ambient water temperatures at a depth of 150–500 m. SMSs have a diverged air-breathing mechanism compared with other vertebrates. The haemoglobin molecule consists of four polypeptide chains, namely two α chains, each with 140 amino acids and two β chains each having 136 amino acids. The SMS Hb was found to crystallize in monoclinic space group P2 1 using the hanging-drop vapour-diffusion method at room temperature. The crystal packing parameters for the SMS Hb structure contain one whole biological molecule in the asymmetric unit with a solvent content of 47%. The SMS Hb quaternary structural features interface–interface interactions and heme binding sites are discussed with different state Hbs and the results reveal that SMS Hb adopts an unliganded deoxy T state conformation

  9. A Comparative Study of Intratesticular Ductules in the Spermatogenically Active Testes of Shortfin Mako and Thresher Sharks.

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    McClusky, Leon Mendel; Sulikowski, James

    2016-10-01

    This comparative study of the radial testes of sexually mature thresher sharks (Alopias vulpinus) and shortfin mako sharks (Isurus oxyrinchus) describes the histology of the three-tiered network of sperm-carrying ductules in the testis and the lymphomyeloid tissue associated with it, namely the epigonal organ. In both species, a testis → epigonal gradient was evident regarding the thickness of the ductule epithelial lining and subepithelial investment of connective tissue. Ductules straddling the testis-epigonal border often displayed luminal leukocytes and various signs of regression, including the progressive thickening of the ductule epithelial lining, dissolution of the cytoplasm, and loss of normal histoarchitecture. In Isurus, large amorphous areas formed due to the fusion of neighboring regressing ductules. The epigonal organ of Alopias additionally revealed circular degenerative sperm-containing, Hassall-like bodies with either a degenerate or cellular appearance, the latter the result of cell proliferative activity (as shown by proliferating cell nuclear antigen (PCNA) immunohistochemistry) in an expanding outer border comprising cells with intensely PCNA immunoreactive slender and oblong nuclei. The latter cells exhibited a periphery-to-center transformation of their nuclei, at which stage they were PCNA-negative and most likely in a terminally differentiated state as they phagocytized the cell debris in the degenerate core. Intermediate stages of these circular bodies were a rarity. The relationship between these degenerate bodies, and the common occurrence of blind pockets in the epithelial linings and non-apoptosis-related degenerate patches in the apical cytoplasmic regions of the irregular shaped ductules in Alopias is unclear, and needs further elucidation. Anat Rec, 299:1435-1448, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  10. Is Host Ectoparasite Load Related to Echeneid Fish Presence?

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    Gonzalo R. Mucientes

    2008-01-01

    Full Text Available This study used field data of echeneid and ectoparasite associations with free-swimming whale sharks (Rhincodon typus and captured mako sharks (Isurus oxyrinchus to test whether (1 echeneid presence was positively correlated with ectoparasite presence; and (2 the number of ectoparasites was negatively correlated with the number of echeneid fish. Data from whale and mako sharks do not support the first hypothesis whereas data from mako sharks yields support for the second hypothesis. The results indicate that echeneids do regulate the number of ectoparasites on at least some host species, but these benefits may be contingent on the echeneid species.

  11. Is Host Ectoparasite Load Related to Echeneid Fish Presence?

    International Nuclear Information System (INIS)

    Mucientes, G.R.; Queiroz, N.; Queiroz, N.; Pierce, S.J.; Pierce, S.J.; Sazima, I.; Brunnschweiler, J.M.

    2008-01-01

    This study used field data of echeneid and ectoparasitic associations with free-swimming whale sharks (Rhincodon typus) and captured mako sharks (Isurus oxyrinchus) to test whether (1) echeneid presence was positively correlated with ectoparasitic presence; and (2) the number of ectoparasitic was negatively correlated with the number of echeneid fish. Data from whale and mako sharks do not support the first hypothesis whereas data from mako sharks yields support for the second hypothesis. The results indicate that echeneids do regulate the number of ectoparasitic on at least some host species, but these benefits may be contingent on the echeneid species.

  12. Phylogenetic relationships and genetic diversity of Nemesis Risso ...

    African Journals Online (AJOL)

    Nemesi s is one of 12 genera in the family Eudactylinidae and includes about nine species. In this study, we investigated whether there is any population structure among Nemesis lamna individuals infecting the white shark Carcharodon carcharias and the shortfin mako Isurus oxyrinchus according to host species or ...

  13. Stable Isotope Analysis of Extant Lamnoid Shark Centra: A New Tool in Age Determination?

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    Labs, J.

    2003-12-01

    The oxygen isotopes of fourteen vertebral centra from ten extant lamnoid sharks (including Carcharodon carcharias [great white], Isurus paucus [longfin mako], and Isurus oxyrinchus [shortfin mako]) were sampled and measured along the growth axis to determine the periodicity of incremental growth represented in the centra. As part of the internal (endochondral) skeleton, shark centra are composed initially of hyaline cartilage, which then secondarily ossifies during ontogeny forming calcified hydroxyapatite bone. The incremental growth of shark centra forms definite growth rings, with darker denser portions being deposited during slower growth times (i.e., winter) and lighter portions being deposited during more rapid growth (i.e., summer). Thus, shark centra, whether they are extant or extinct, are characterized by clearly delineated incremental growth couplets. The problem with this general rule is that there are several factors in which the growth of these couplets can vary depending upon physical environment (including temperature and water depth), food availability, and stress. The challenge for paleobiological interpretations is how to interpret the periodicity of this growth. It can generally be assumed that these bands are annual, but it is uncertain the extent to which exceptions to the rule occur. Stable isotopic analysis provides the potential to independently determine the periodicity of the growth increments and ultimately the ontogenetic age of an individual.

  14. Spatial ecology of blue shark and shortfin mako in southern Peru: local abundance, habitat preferences and implications for conservation

    DEFF Research Database (Denmark)

    Adams, Grant D.; Flores, Daniel; Flores, Oscar Galindo

    2016-01-01

    While global declines of pelagic shark populations have been recognized for several years, conservation efforts remain hampered by a poor understanding of the spatial distribution and ecology. Two species of conservation concern are the blue shark Prionace glauca and the shortfin mako shark Isuru...

  15. Catch, effort and bycatch of longline fishery in central Peru

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    Liliana Ayala

    2014-12-01

    Full Text Available The aims of this study is to report some characteristics of fishing trips, effort, catches, fishing areas and bycatch through observations on board and logbooks. 85% of sets were in the first 574 Km of distance from the coast (309 nautical miles. Farthest set was located at 1320 Km (712 nautical miles. A total of 382000 hooks were used to catch Mahi mahi, in 224 sets and 29 fishing trips, 94.6% of catch was Mahi mahi, 2.7% blue shark (Prionace glauca y 1,3% mako shark (Isurus oxyrinchus. Also, 103790 hooks were used to catch sharks, in 109 sets y 12 trips, 81.9% of catch was blue sharks and 16.8% mako sharks. Catch per Unit of Effort (CPUE for Mahi mahi shows significative difference among seasons; with a peak from November to January. CPUE for shark shows significative difference among seasons, with peaks in September and October. The Green turtle Chelonia mydas agassizii was the most caugth species and two of three were juveniles. All Loggerhead turtles, Caretta caretta, caught were juveniles. A petrel is reported as bycatch and, probably, mammal bycatch is scarce. Considering the huge effort of this fishery, it is important to monitor it and establish management actions.

  16. Postrelease survival, vertical and horizontal movements, and thermal habitats of five species of pelagic sharks in the central Pacific Ocean

    DEFF Research Database (Denmark)

    Musyl, Michael K.; Brill, Richard W.; Curran, Daniel S.

    2011-01-01

    ]) in the central Pacific Ocean to determine speciesspecific movement patterns and survival rates after release from longline fishing gear. Only a single postrelease mortality could be unequivocally documented: a male blue shark which succumbed seven days after release. Meta-analysis of published reports......From 2001 to 2006, 71 pop-up satellite archival tags (PSATs) were deployed on five species of pelagic shark (blue shark [Prionace glauca]; shortfin mako [Isurus oxyrinchus]; silky shark [Carcharhinus falciformis]; oceanic whitetip shark [C. longimanus]; and bigeye thresher [Alopias superciliosus...... and the current study (n=78 reporting PSATs) indicated that the summary effect of postrelease mortality for blue sharks was 15% (95% CI, 8.5-25.1%) and suggested that catch-and-release in longline fisheries can be a viable management tool to protect parental biomass in shark populations. Pelagic sharks displayed...

  17. Satellite telemetry reveals higher fishing mortality rates than previously estimated, suggesting overfishing of an apex marine predator.

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    Byrne, Michael E; Cortés, Enric; Vaudo, Jeremy J; Harvey, Guy C McN; Sampson, Mark; Wetherbee, Bradley M; Shivji, Mahmood

    2017-08-16

    Overfishing is a primary cause of population declines for many shark species of conservation concern. However, means of obtaining information on fishery interactions and mortality, necessary for the development of successful conservation strategies, are often fisheries-dependent and of questionable quality for many species of commercially exploited pelagic sharks. We used satellite telemetry as a fisheries-independent tool to document fisheries interactions, and quantify fishing mortality of the highly migratory shortfin mako shark ( Isurus oxyrinchus ) in the western North Atlantic Ocean. Forty satellite-tagged shortfin mako sharks tracked over 3 years entered the Exclusive Economic Zones of 19 countries and were harvested in fisheries of five countries, with 30% of tagged sharks harvested. Our tagging-derived estimates of instantaneous fishing mortality rates ( F = 0.19-0.56) were 10-fold higher than previous estimates from fisheries-dependent data (approx. 0.015-0.024), suggesting data used in stock assessments may considerably underestimate fishing mortality. Additionally, our estimates of F were greater than those associated with maximum sustainable yield, suggesting a state of overfishing. This information has direct application to evaluations of stock status and for effective management of populations, and thus satellite tagging studies have potential to provide more accurate estimates of fishing mortality and survival than traditional fisheries-dependent methodology. © 2017 The Author(s).

  18. Lithological architecture and petrography of the Mako Birimian greenstone belt, Kédougou-Kéniéba Inlier, eastern Senegal

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    Dabo, Moussa; Aïfa, Tahar; Gning, Ibrahima; Faye, Malick; Ba, Mamadou Fallou; Ngom, Papa Malick

    2017-07-01

    The new lithological and petrographic data obtained in the Mako sector are analyzed in the light of the geochemical data available in the literature. It consists of ultramaic, mafic rocks of tholeiitic affinities associated with intermediate and felsic rocks of calc-alkaline affinities and with intercalations of sedimentary rocks. The whole unit is intruded by Eburnean granitoids and affected by a greenschist to amphibolite facies metamorphism related to a high grade hydrothermalism. It consists of: (i) ultramafic rocks composed of a fractional crystallization succession of lherzolites, wehrlites and pyroxenites with mafic rock inclusions; (ii) layered, isotropic and pegmatitic metagabbros which gradually pass to metabasalts occur at the top; (iii) massive and in pillow metabasalts with locally tapered vesicles, completely or partially filled with quartzo-feldspathic minerals; (iv) quarzites locally overlying the mafic rocks and thus forming the top of the lower unit. This ultramafic-mafic lower unit presents a tholeiitic affinity near to the OIB or N-MORB. It represents the Mako Ophiolitic Complex (MOC), a lithospheric fragment of Birimian lithospheric crust. The upper unit is a mixed volcanic complex arranged in the tectonic corridors. From bottom to top it comprises the following: (i) andesitic, and (ii) rhyodacitic and rhyolitic lava flows and tuffs, respectively. They present a calc-alkaline affinity of the active margins. Three generations of Eburnean granitoids are recognized: (i) early (2215-2160 Ma); (ii) syn-tectonics (2150-2100 Ma) and post-tectonics (2090-2040 Ma). The lithological succession, geochemical and metamorphic characteristics of these units point to an ophiolitic supra-subduction zone.

  19. Multiple prismatic calcium phosphate layers in the jaws of present-day sharks (Chondrichthyes; Selachii).

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    Dingerkus, G; Séret, B; Guilbert, E

    1991-01-15

    Jaws of large individuals, over 2 m in total length, of the shark species Carcharodon carcharias (great white shark) and Isurus oxyrinchus (mako shark) of the family Lamnidae, and Galeocerdo cuvieri (tiger shark) and Carcharhinus leucas (bull shark) of the family Carcharhinidae were found to have multiple, up to five, layers of prismatic calcium phosphate surrounding the cartilages. Smaller individuals of these species and other known species of living chondrichthyans have only one layer of prismatic calcium phosphate surrounding the cartilages, as also do most species of fossil chondrichthyans. Two exceptions are the fossil shark genera Xenacanthus and Tamiobatis. Where it is found in living forms, this multiple layered calcification does not appear to be phylogenetic, as it appears to be lacking in other lamnid and carcharhinid genera and species. Rather it appears to be functional, only appearing in larger individuals and species of these two groups, and hence may be necessary to strengthen the jaw cartilages of such individuals for biting.

  20. Movable shark scales act as a passive dynamic micro-roughness to control flow separation

    International Nuclear Information System (INIS)

    Lang, Amy W; Bradshaw, Michael T; Smith, Jonathon A; Wheelus, Jennifer N; Motta, Philip J; Habegger, Maria L; Hueter, Robert E

    2014-01-01

    Shark scales on fast-swimming sharks have been shown to be movable to angles in excess of 50°, and we hypothesize that this characteristic gives this shark skin a preferred flow direction. During the onset of separation, flow reversal is initiated close to the surface. However, the movable scales would be actuated by the reversed flow thereby causing a greater resistance to any further flow reversal and this mechanism would disrupt the process leading to eventual flow separation. Here we report for the first time experimental evidence of the separation control capability of real shark skin through water tunnel testing. Using skin samples from a shortfin mako Isurus oxyrinchus, we tested a pectoral fin and flank skin attached to a NACA 4412 hydrofoil and separation control was observed in the presence of movable shark scales under certain conditions in both cases. We hypothesize that the scales provide a passive, flow-actuated mechanism acting as a dynamic micro-roughness to control flow separation. (paper)

  1. Effects of trophic ecology and habitat use on maternal transfer of contaminants in four species of young of the year lamniform sharks.

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    Lyons, Kady; Carlisle, Aaron; Preti, Antonella; Mull, Christopher; Blasius, Mary; O'Sullivan, John; Winkler, Chuck; Lowe, Christopher G

    2013-09-01

    Organic contaminant and total mercury concentrations were compared in four species of lamniform sharks over several age classes to examine bioaccumulation patterns and gain insights into trophic ecology. Contaminants found in young of the year (YOY) sharks were assumed to be derived from maternal sources and used as a proxy to investigate factors that influence maternal offloading processes. YOY white (Carcharodon carcharias) and mako (Isurus oxyrinchus) sharks had comparable and significantly higher concentrations of PCBs, DDTs, pesticides, and mercury than YOY thresher (Alopias vulpinus) or salmon (Lamna ditropis) sharks. A significant positive relationship was found between YOY contaminant loads and maternal trophic position, suggesting that trophic ecology is one factor that plays an important role in maternal offloading. Differences in organic contaminant signatures and contaminant concentration magnitudes among species corroborated what is known about species habitat use and may be used to provide insights into the feeding ecology of these animals. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

  3. New Mediterranean Marine biodiversity records (December, 2013

    Directory of Open Access Journals (Sweden)

    M. BILECENOGLU

    2013-10-01

    Full Text Available Based on recent biodiversity studies carried out in different parts of the Mediterranean, the following 19 species are included as new records on the floral or faunal lists of the relevant ecosystems: the green algae Penicillus capitatus (Maltese waters; the nemertean Amphiporus allucens (Iberian Peninsula, Spain; the salp Salpa maxima (Syria; the opistobranchs Felimida britoi and Berghia coerulescens (Aegean Sea, Greece; the dusky shark Carcharhinus obscurus (central-west Mediterranean and Ionian Sea, Italy; Randall’s threadfin bream Nemipterus randalli, the broadbanded cardinalfish Apogon fasciatus and the goby Gobius kolombatovici (Aegean Sea, Turkey; the reticulated leatherjack Stephanolepis diaspros and the halacarid Agaue chevreuxi (Sea of Marmara, Turkey; the slimy liagora Ganonema farinosum, the yellowstripe barracuda Sphyraena chrysotaenia, the rayed pearl oyster Pinctada imbricata radiata and the Persian conch Conomurex persicus (south-eastern Crete, Greece; the blenny Microlipophrys dalmatinus and the bastard grunt Pomadasys incisus (Ionian Sea, Italy; the brown shrimp Farfantepenaeus aztecus (north-eastern Levant, Turkey; the blue-crab Callinectes sapidus (Corfu, Ionian Sea, Greece. In addition, the findings of the following rare species improve currently available biogeographical knowledge: the oceanic pufferfish Lagocephalus lagocephalus (Malta; the yellow sea chub Kyphosus incisor (Almuñécar coast of Spain; the basking shark Cetorhinus maximus and the shortfin mako Isurus oxyrinchus (north-eastern Levant, Turkey.

  4. Population trends in Pacific Oceanic sharks and the utility of regulations on shark finning.

    Science.gov (United States)

    Clarke, Shelley C; Harley, Shelton J; Hoyle, Simon D; Rice, Joel S

    2013-02-01

    Accurate assessment of shark population status is essential for conservation but is often constrained by limited and unreliable data. To provide a basis for improved management of shark resources, we analyzed a long-term record of species-specific catches, sizes, and sexes of sharks collected by onboard observers in the western and central Pacific Ocean from 1995 to 2010. Using generalized linear models, we estimated population-status indicators on the basis of catch rate and biological indicators of fishing pressure on the basis of median size to identify trends for blue (Prionace glauca), mako (Isurus spp.), oceanic whitetip (Carcharhinus longimanus), and silky (Carcharhinus falciformis) sharks. Standardized catch rates of longline fleets declined significantly for blue sharks in the North Pacific (by 5% per year [CI 2% to 8%]), for mako sharks in the North Pacific (by 7% per year [CI 3% to 11%]), and for oceanic whitetip sharks in tropical waters (by 17% per year [CI 14% to 20%]). Median lengths of silky and oceanic whitetip sharks decreased significantly in their core habitat, and almost all sampled silky sharks were immature. Our results are consistent with results of analyses of similar data sets. Combined, these results and evidence of targeted fishing for sharks in some regional fisheries heighten concerns for sustainable utilization, particularly for oceanic whitetip and North Pacific blue sharks. Regional regulations that prohibit shark finning (removal of fins and discarding of the carcass) were enacted in 2007 and are in many cases the only form of control on shark catches. However, there is little evidence of a reduction of finning in longline fisheries. In addition, silky and oceanic whitetip sharks are more frequently retained than finned, which suggests that even full implementation of and adherence to a finning prohibition may not substantially reduce mortality rates for these species. We argue that finning prohibitions divert attention from

  5. Shark-Cetacean trophic interaction, Duinefontein, Koeberg, (5 Ma, South Africa

    Directory of Open Access Journals (Sweden)

    Romala Govender

    2015-11-01

    Full Text Available This study forms part of a larger project to reconstruct the Mio-Pliocene marine palaeoenvironment along South Africa’s west coast. It documents the shark–cetacean trophic interaction during the Zanclean (5 Ma at Duinefontein (Koeberg. The damage described on the fragmentary cetacean bones was compared with similar damage observed on fossils from Langebaanweg, a Mio-Pliocene site on the west coast of South Africa, and data present in the literature. This comparison showed that the damage was the result of shark bites. The state of preservation makes it difficult to determine if the shark bite marks were the cause of death or as a result of scavenging. The presence of the bite marks on the bone would, however, indicate some degree of skeletonisation. Bite marks on some cranial fragments would suggest that the cetacean’s body was in an inverted position typical of a floating carcass. The preservation of the material suggests that the bones were exposed to wave action resulting in their fragmentation as well as abrasion, polishing and rolling. It also suggests that the cetacean skeletons were exposed for a long time prior to burial. The morphology of the bites suggests that the damage was inflicted by sharks with serrated and unserrated teeth. Shark teeth collected from the deposit include megalodon (Carcharodon megalodon, white (Carcharodon carcharias as well as mako (Isurus sp. and Cosmopolitodus hastalis sharks, making these sharks the most likely predators/scavengers.

  6. Shark fisheries in the Southeast Pacific: A 61-year analysis from Peru [version 2; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Adriana Gonzalez-Pestana

    2016-04-01

    Full Text Available Peruvian waters exhibit high conservation value for sharks. This contrasts with a lag in initiatives for their management and a lack of studies about their biology, ecology and fishery. We investigated the dynamics of Peruvian shark fishery and its legal framework identifying information gaps for recommending actions to improve management. Further, we investigated the importance of the Peruvian shark fishery from a regional perspective. From 1950 to 2010, 372,015 tons of sharks were landed in Peru. From 1950 to 1969, we detected a significant increase in landings; but from 2000 to 2011 there was a significant decrease in landings, estimated at 3.5% per year. Six species represented 94% of landings: blue shark (Prionace glauca, shortfin mako (Isurus oxyrinchus, smooth hammerhead (Sphyrna zygaena, common thresher (Alopias vulpinus, smooth-hound (Mustelus whitneyi and angel shark (Squatina californica. Of these, the angel shark exhibits a strong and significant decrease in landings: 18.9% per year from 2000 to 2010. Peru reports the highest accumulated historical landings in the Pacific Ocean; but its contribution to annual landings has decreased since 1968. Still, Peru is among the top 12 countries exporting shark fins to the Hong Kong market. Although the government collects total weight by species, the number of specimens landed as well as population parameters (e.g. sex, size and weight are not reported. Further, for some genera, species-level identification is deficient and so overestimates the biomass landed by species and underestimates the species diversity. Recently, regional efforts to regulate shark fishery have been implemented to support the conservation of sharks but in Peru work remains to be done.

  7. Estimating Finite Rate of Population Increase for Sharks Based on Vital Parameters.

    Directory of Open Access Journals (Sweden)

    Kwang-Ming Liu

    Full Text Available The vital parameter data for 62 stocks, covering 38 species, collected from the literature, including parameters of age, growth, and reproduction, were log-transformed and analyzed using multivariate analyses. Three groups were identified and empirical equations were developed for each to describe the relationships between the predicted finite rates of population increase (λ' and the vital parameters, maximum age (Tmax, age at maturity (Tm, annual fecundity (f/Rc, size at birth (Lb, size at maturity (Lm, and asymptotic length (L∞. Group (1 included species with slow growth rates (0.034 yr(-1 < k < 0.103 yr(-1 and extended longevity (26 yr < Tmax < 81 yr, e.g., shortfin mako Isurus oxyrinchus, dusky shark Carcharhinus obscurus, etc.; Group (2 included species with fast growth rates (0.103 yr(-1 < k < 0.358 yr(-1 and short longevity (9 yr < Tmax < 26 yr, e.g., starspotted smoothhound Mustelus manazo, gray smoothhound M. californicus, etc.; Group (3 included late maturing species (Lm/L∞ ≧ 0.75 with moderate longevity (Tmax < 29 yr, e.g., pelagic thresher Alopias pelagicus, sevengill shark Notorynchus cepedianus. The empirical equation for all data pooled was also developed. The λ' values estimated by these empirical equations showed good agreement with those calculated using conventional demographic analysis. The predictability was further validated by an independent data set of three species. The empirical equations developed in this study not only reduce the uncertainties in estimation but also account for the difference in life history among groups. This method therefore provides an efficient and effective approach to the implementation of precautionary shark management measures.

  8. Shark fisheries in the Southeast Pacific: A 61-year analysis from Peru

    Science.gov (United States)

    Gonzalez-Pestana, Adriana; Kouri J., Carlos; Velez-Zuazo, Ximena

    2016-01-01

    Peruvian waters exhibit high conservation value for sharks. This contrasts with a lag in initiatives for their management and a lack of studies about their biology, ecology and fishery. We investigated the dynamics of Peruvian shark fishery and its legal framework identifying information gaps for recommending actions to improve management. Further, we investigated the importance of the Peruvian shark fishery from a regional perspective. From 1950 to 2010, 372,015 tons of sharks were landed in Peru. From 1950 to 1969, we detected a significant increase in landings; but from 2000 to 2011 there was a significant decrease in landings, estimated at 3.5% per year. Six species represented 94% of landings: blue shark ( Prionace glauca), shortfin mako ( Isurus oxyrinchus), smooth hammerhead ( Sphyrna zygaena), common thresher ( Alopias vulpinus), smooth-hound ( Mustelus whitneyi) and angel shark ( Squatina californica). Of these, the angel shark exhibits a strong and significant decrease in landings: 18.9% per year from 2000 to 2010. Peru reports the highest accumulated historical landings in the Pacific Ocean; but its contribution to annual landings has decreased since 1968. Still, Peru is among the top 12 countries exporting shark fins to the Hong Kong market. Although the government collects total weight by species, the number of specimens landed as well as population parameters (e.g. sex, size and weight) are not reported. Further, for some genera, species-level identification is deficient and so overestimates the biomass landed by species and underestimates the species diversity. Recently, regional efforts to regulate shark fishery have been implemented to support the conservation of sharks but in Peru work remains to be done. PMID:27635216

  9. Plasticity of trophic interactions among sharks from the oceanic south-western Indian Ocean revealed by stable isotope and mercury analyses

    Science.gov (United States)

    Kiszka, Jeremy J.; Aubail, Aurore; Hussey, Nigel E.; Heithaus, Michael R.; Caurant, Florence; Bustamante, Paco

    2015-02-01

    Sharks are a major component of the top predator guild in oceanic ecosystems, but the trophic relationships of many populations remain poorly understood. We examined chemical tracers of diet and habitat (δ15N and δ13C, respectively) and total mercury (Hg) concentrations in muscle tissue of seven pelagic sharks: blue shark (Prionace glauca), short-fin mako shark (Isurus oxyrinchus), oceanic whitetip shark (Carcharhinus longimanus), scalloped hammerhead shark (Sphyrna lewini), pelagic thresher shark (Alopias pelagicus), crocodile shark (Pseudocarcharias kamoharai) and silky shark (Carcharhinus falciformis), from the data poor south-western tropical Indian Ocean. Minimal interspecific variation in mean δ15N values and a large degree of isotopic niche overlap - driven by high intraspecific variation in δ15N values - was observed among pelagic sharks. Similarly, δ13C values of sharks overlapped considerably for all species with the exception of P. glauca, which had more 13C-depleted values indicating possibly longer residence times in purely pelagic waters. Geographic variation in δ13C, δ15N and Hg were observed for P. glauca and I. oxyrinchus. Mean Hg levels were similar among species with the exception of P. kamoharai which had significantly higher Hg concentrations likely related to mesopelagic feeding. Hg concentrations increased with body size in I. oxyrinchus, P. glauca and C. longimanus. Values of δ15N and δ13C varied with size only in P. glauca, suggesting ontogenetic shifts in diets or habitats. Together, isotopic data indicate that - with few exceptions - variance within species in trophic interactions or foraging habitats is greater than differentiation among pelagic sharks in the south-western Indian Ocean. Therefore, it is possible that this group exhibits some level of trophic redundancy, but further studies of diets and fine-scale habitat use are needed to fully test this hypothesis.

  10. Biomimetic shark skin: design, fabrication and hydrodynamic function.

    Science.gov (United States)

    Wen, Li; Weaver, James C; Lauder, George V

    2014-05-15

    Although the functional properties of shark skin have been of considerable interest to both biologists and engineers because of the complex hydrodynamic effects of surface roughness, no study to date has successfully fabricated a flexible biomimetic shark skin that allows detailed study of hydrodynamic function. We present the first study of the design, fabrication and hydrodynamic testing of a synthetic, flexible, shark skin membrane. A three-dimensional (3D) model of shark skin denticles was constructed using micro-CT imaging of the skin of the shortfin mako (Isurus oxyrinchus). Using 3D printing, thousands of rigid synthetic shark denticles were placed on flexible membranes in a controlled, linear-arrayed pattern. This flexible 3D printed shark skin model was then tested in water using a robotic flapping device that allowed us to either hold the models in a stationary position or move them dynamically at their self-propelled swimming speed. Compared with a smooth control model without denticles, the 3D printed shark skin showed increased swimming speed with reduced energy consumption under certain motion programs. For example, at a heave frequency of 1.5 Hz and an amplitude of ± 1 cm, swimming speed increased by 6.6% and the energy cost-of-transport was reduced by 5.9%. In addition, a leading-edge vortex with greater vorticity than the smooth control was generated by the 3D printed shark skin, which may explain the increased swimming speeds. The ability to fabricate synthetic biomimetic shark skin opens up a wide array of possible manipulations of surface roughness parameters, and the ability to examine the hydrodynamic consequences of diverse skin denticle shapes present in different shark species. © 2014. Published by The Company of Biologists Ltd.

  11. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa.

    Science.gov (United States)

    McKinney, Melissa A; Dean, Kylie; Hussey, Nigel E; Cliff, Geremy; Wintner, Sabine P; Dudley, Sheldon F J; Zungu, M Philip; Fisk, Aaron T

    2016-01-15

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH3Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n=283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg(-1) dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg(-1) dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ(15)N), whereas measures of foraging habitat (using carbon stable isotopes, δ(13)C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Species composition of the international shark fin trade assessed through a retail-market survey in Hong Kong.

    Science.gov (United States)

    Fields, Andrew T; Fischer, Gunter A; Shea, Stanley K H; Zhang, Huarong; Abercrombie, Debra L; Feldheim, Kevin A; Babcock, Elizabeth A; Chapman, Demian D

    2018-04-01

    The shark fin trade is a major driver of shark exploitation in fisheries all over the world, most of which are not managed on a species-specific basis. Species-specific trade information highlights taxa of particular concern and can be used to assess the efficacy of management measures and anticipate emerging threats. The species composition of the Hong Kong Special Administrative Region of China, one of the world's largest fin trading hubs, was partially assessed in 1999-2001. We randomly selected and genetically identified fin trimmings (n = 4800), produced during fin processing, from the retail market of Hong Kong in 2014-2015 to assess contemporary species composition of the fin trade. We used nonparametric species estimators to determine that at least 76 species of sharks, batoids, and chimaeras supplied the fin trade and a Bayesian model to determine their relative proportion in the market. The diversity of traded species suggests species substitution could mask depletion of vulnerable species; one-third of identified species are threatened with extinction. The Bayesian model suggested that 8 species each comprised >1% of the fin trimmings (34.1-64.2% for blue [Prionace glauca], 0.2-1.2% for bull [Carcharhinus leucas] and shortfin mako [Isurus oxyrinchus]); thus, trade was skewed to a few globally distributed species. Several other coastal sharks, batoids, and chimaeras are in the trade but poorly managed. Fewer than 10 of the species we modeled have sustainably managed fisheries anywhere in their range, and the most common species in trade, the blue shark, was not among them. Our study and approach serve as a baseline to track changes in composition of species in the fin trade over time to better understand patterns of exploitation and assess the effects of emerging management actions for these animals. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

  13. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa

    International Nuclear Information System (INIS)

    McKinney, Melissa A.; Dean, Kylie; Hussey, Nigel E.; Cliff, Geremy; Wintner, Sabine P.; Dudley, Sheldon F.J.; Zungu, M. Philip; Fisk, Aaron T.

    2016-01-01

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH_3Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n = 283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg"−"1 dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg"−"1 dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ"1"5N), whereas measures of foraging habitat (using carbon stable isotopes, δ"1"3C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. - Highlights: • Hg concentrations in 17 shark species from South Africa's east coast were measured. • Higher values relative to other regions suggested the importance of local emissions. • Length and

  14. Ventricle morphology in pelagic elasmobranch fishes.

    Science.gov (United States)

    Emery, S H; Mangano, C; Randazzo, V

    1985-01-01

    Ventricle weights of the warm-bodied great white shark, Atlantic shortfin mako, and the common thresher shark (the latter presumed to be warm-bodied) are similar to those of ectothermic blue sharks, sandbar sharks, dusky sharks, tiger sharks and scalloped hammerhead sharks. Ventricle muscularity, as estimated by the ratio of cortical to spongy layer thickness, is almost twice as great in the former three species than in the latter elasmobranchs. Measurements of ventricular volumes suggest that the ventricles of the great white, Atlantic shortfin mako and common thresher sharks are better adapted to respond to demands for increases in cardiac output via increased heartbeat frequency in comparison with ectothermic species of shark.

  15. Impact of biology knowledge on the conservation and management of large pelagic sharks.

    Science.gov (United States)

    Yokoi, Hiroki; Ijima, Hirotaka; Ohshimo, Seiji; Yokawa, Kotaro

    2017-09-06

    Population growth rate, which depends on several biological parameters, is valuable information for the conservation and management of pelagic sharks, such as blue and shortfin mako sharks. However, reported biological parameters for estimating the population growth rates of these sharks differ by sex and display large variability. To estimate the appropriate population growth rate and clarify relationships between growth rate and relevant biological parameters, we developed a two-sex age-structured matrix population model and estimated the population growth rate using combinations of biological parameters. We addressed elasticity analysis and clarified the population growth rate sensitivity. For the blue shark, the estimated median population growth rate was 0.384 with a range of minimum and maximum values of 0.195-0.533, whereas those values of the shortfin mako shark were 0.102 and 0.007-0.318, respectively. The maturity age of male sharks had the largest impact for blue sharks, whereas that of female sharks had the largest impact for shortfin mako sharks. Hypotheses for the survival process of sharks also had a large impact on the population growth rate estimation. Both shark maturity age and survival rate were based on ageing validation data, indicating the importance of validating the quality of these data for the conservation and management of large pelagic sharks.

  16. Global versus local causes and health implications of high mercury concentrations in sharks from the east coast of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, Melissa A., E-mail: melissa.mckinney@uconn.edu [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Dean, Kylie; Hussey, Nigel E. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Cliff, Geremy; Wintner, Sabine P. [KwaZulu-Natal Sharks Board, Umhlanga Rocks 4320 (South Africa); Biomedical Resource Unit, University of KwaZulu-Natal, Durban 4000 (South Africa); Dudley, Sheldon F.J. [KwaZulu-Natal Sharks Board, Umhlanga Rocks 4320 (South Africa); Department of Agriculture, Forestry and Fisheries, Cape Town 8012 (South Africa); Zungu, M. Philip [Department of Agriculture, Forestry and Fisheries, Cape Town 8012 (South Africa); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada)

    2016-01-15

    Conservation concern regarding the overharvest of global shark populations for meat and fin consumption largely surrounds documented deleterious ecosystem effects, but may be further supported by improved knowledge of possibly high levels in their edible tissues (particularly meat) of the neurotoxin, methylmercury (CH{sub 3}Hg). For many regions, however, little data exist on shark tissue Hg concentrations, and reasons for Hg variation within and among species or across regions are poorly understood. We quantified total Hg (THg) in 17 shark species (total n = 283) from the east coast of South Africa, a top Hg emitter globally. Concentrations varied from means of around 0.1 mg kg{sup −1} dry weight (dw) THg in hardnose smoothhound (Mustelus mosis) and whale (Rhincodon typus) sharks to means of over 10 mg kg{sup −1} dw in shortfin mako (Isurus oxyrinchus), scalloped hammerhead (Sphyrna lewini), white (Carcharodon carcharias) and ragged-tooth (Carcharias taurus) sharks. These sharks had higher THg levels than conspecifics sampled from coastal waters of the North Atlantic and North, mid-, and South Pacific, and although sampling year and shark size may play a confounding role, this result suggests the potential importance of elevated local emissions. Values of THg showed strong, species-specific correlations with length, and nearly half the remaining variation was explained by trophic position (using nitrogen stable isotopes, δ{sup 15}N), whereas measures of foraging habitat (using carbon stable isotopes, δ{sup 13}C) were not significant. Mercury concentrations were above the regulatory guidelines for fish health effects and safe human consumption for 88% and 70% of species, respectively, suggesting on-going cause for concern for shark health, and human consumers of shark meat. - Highlights: • Hg concentrations in 17 shark species from South Africa's east coast were measured. • Higher values relative to other regions suggested the importance of local

  17. Fish remains from Miocene beds of Višnja vas near Vojnik, Slovenia

    Directory of Open Access Journals (Sweden)

    Aleš Šoster

    2013-06-01

    Full Text Available This paper discusses fossil teeth of sharks (Elasmobranchii, Neoselachii and porgies (Teleostei, Sparidae fromthe Miocene glauconite sandstones of Vi{nja vas near Vojnik. The remains of fish teeth, mostly tooth crowns, belongto cartilaginous fishes of the genera Notorynchus, Carcharias, Carcharoides, Isurus and Cosmopolitodus and to abony fish genus Pagrus.

  18. 75 FR 30483 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Amendment 3

    Science.gov (United States)

    2010-06-01

    ... and 635 Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Amendment 3; Final Rule... and 635 [Docket No. 080519678-0217-02] RIN 0648-AW65 Atlantic Highly Migratory Species; Atlantic Shark... available to rebuild blacknose sharks and end overfishing of blacknose and shortfin mako sharks, consistent...

  19. Media Literacy and Cigarette Smoking in Hungarian Adolescents

    Science.gov (United States)

    Page, Randy M.; Piko, Bettina F.; Balazs, Mate A.; Struk, Tamara

    2011-01-01

    Objective: To assess smoking media literacy in a sample of Hungarian youth and to determine its association with current smoking and susceptibility to future smoking. Design: Quantitative cross-sectional survey. Setting: Four elementary and four high schools in Mako, Hungary. Method: A survey form was administered in regularly-scheduled classes to…

  20. 77 FR 60632 - Atlantic Highly Migratory Species; Silky Shark Management Measures

    Science.gov (United States)

    2012-10-04

    ... assessment. NMFS needs to conduct a full benchmark stock assessment for silky sharks as soon as possible... mako stock. This approach is also consistent with National Standard 3 that states that to the extent practicable, an individual stock of fish shall be managed as a unit throughout its range, and interrelated...

  1. Ictiofauna del mioceno inferior de la localidad de Pacuare de Tres Equis, formación río Banano, provincia de Cartago, Costa Rica, y descripción de un nuevo género y una nueva especie de scaridae

    OpenAIRE

    César A. Laurito; Cristian Calvo; Ana L. Valerio; Alejandro Calvo; Rafael Chacón

    2014-01-01

    Se estudia la ictiofauna de la localidad de Pacuare de Tres Equis de edad Mioceno Inferior donde se registran 8 géneros de tiburones: Heptranchias, Megaselachus, Isurus, Carcharias, Mitsukurina, Hemipristis, Negaprion y Carcharhinus; y 6 familias de osteíctios, Sparidae, Acanthuridae, Scaridae, Labridae, Sphyraenidae y Tetraodontidae. Esta asociación de peces sugiere un ambiente marino sublitoral - nerítico, con aguas cálidas tropicales y salinidad normal.

  2. New specimens and records of chondrichthyan fishes (Vertebrata: Chondrichthyes off the Mexican Pacific coast Nuevos ejemplares y nuevos registros de peces cartilaginosos (Vertebrata: Chondrichthyes de la costa del Pacífico mexicano

    Directory of Open Access Journals (Sweden)

    Gorgonio Ruiz-Campos

    2010-08-01

    Full Text Available New specimens and new records of occurrence for 10 species of chondrichthyan (elasmobranch and chimaeroid fishes previously unknown or little documented for the continental shelf of the Mexican Pacific are reported. This contribution provides the first record of Centroscyllium nigrum, Isurus paucus, and Bathyraja trachura for the Mexican Pacific, as well as new specimens of Hydrolagus colliei, Hexanchus griseus, Echinorhinus cookei, Pseudocarcharias kamoharai, and Raja velezi for the western coast of the Baja California Peninsula, including the intermediate record within the known distribution range for Apristurus kampae, and the southernmost record for Raja inornata.Se reportan nuevos ejemplares y nuevos registros de concurrencia para 10 especies de elasmobranquios previamente desconocidos o con muy poca documentación en aguas del Pacífico mexicano. Esta contribución ofrece el primer registro de Centroscyllium nigrum, Isurus paucus, y Bathyraja trachura en el Pacífico mexicano; así como nuevos ejemplares de Hydrolagus colliei, Hexanchus griseus, Echinorhinus cookei, Pseudocarcharias kamoharai y Raja velezi en la costa occidental de la península de Baja California, con la inclusión del registro intermedio en el ámbito de distribución conocida para Apristurus kampae, y el registro más meridional para Raja inornata.

  3. Ictiofauna del mioceno inferior de la localidad de Pacuare de Tres Equis, formación río Banano, provincia de Cartago, Costa Rica, y descripción de un nuevo género y una nueva especie de scaridae

    OpenAIRE

    Laurito, César A.; Calvo, Cristian; Valerio, Ana L.; Calvo, Alejandro; Chacón, Rafael

    2014-01-01

    Se estudia la ictiofauna de la localidad de Pacuare de Tres Equis de edad Mioceno Inferior donde se registran 8 géneros de tiburones: Heptranchias, Megaselachus, Isurus, Carcharias, Mitsukurina, Hemipristis, Negaprion y Carcharhinus; y 6 familias de osteíctios, Sparidae, Acanthuridae, Scaridae, Labridae, Sphyraenidae y Tetraodontidae. Esta asociación de peces sugiere un ambiente marino sublitoral - nerítico, con aguas cálidas tropicales y salinidad normal. A studied of the Lower Miocene fi...

  4. Impact of biology knowledge on the conservation and management of large pelagic sharks

    OpenAIRE

    Yokoi, Hiroki; Ijima, Hirotaka; Ohshimo, Seiji; Yokawa, Kotaro

    2017-01-01

    Population growth rate, which depends on several biological parameters, is valuable information for the conservation and management of pelagic sharks, such as blue and shortfin mako sharks. However, reported biological parameters for estimating the population growth rates of these sharks differ by sex and display large variability. To estimate the appropriate population growth rate and clarify relationships between growth rate and relevant biological parameters, we developed a two-sex age-str...

  5. Discovery of riblets in a bird beak (Rynchops) for low fluid drag.

    Science.gov (United States)

    Martin, Samuel; Bhushan, Bharat

    2016-08-06

    Riblet structures found on fast-swimming shark scales, such as those found on a mako shark, have been shown to reduce fluid drag. In previous experimental and modelling studies, riblets have been shown to provide drag reduction by lifting vortices formed in turbulent flow, decreasing overall shear stresses. Skimmer birds (Rynchops) are the only birds to catch fish in flight by flying just above the water surface with a submerged beak to fish for food. Because they need to quickly catch prey, reducing drag on their beak is advantageous. For the first time, riblet structures found on the beak of the skimmer bird have been studied experimentally and computationally for low fluid drag properties. In this study, skimmer replicas were studied for drag reduction through pressure drop in closed-channel, turbulent water flow. Pressure drop measurements are compared for black and yellow skimmer beaks in two configurations, and mako shark skin. In addition, two configurations of skimmer beak were modelled to compare drag properties and vortex structures. Results are discussed, and a conceptual model is presented to explain a possible drag reduction mechanism in skimmers.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  6. Desembarque artesanal en Ilo Moquegua: Flota espinelera. 1994-2001

    OpenAIRE

    Treviño Bernal, Hugo; Tejada Cáceres, Alex; Zambrano Pinto, Martín; Huamaní Delgado, Isaac

    2016-01-01

    La flota espinelera artesanal de Ilo-Moquegua, durante los años 1994-2001 desembarcó especies oceánicas. La información sobre áreas de pesca, volúmenes de captura, composición por especies, número de anzuelos, tipo de carnada y días de pesca se obtuvo de los pescadores espineleros. Se desembarcaron 11 especies, destacando: perico (Coryphaena hippurus), tiburón azul (Prionace glauca), tiburón diamante (Isurus oxyrinchus), pez espada (Xiphias gladius) y tiburón martillo (Sphyrna zygaena). Otras...

  7. The The geothermal potentials for electric development in Maluku Province

    OpenAIRE

    Isnaniawardhani, Vijaya; Sukiyah, Emi; Sudradjat, Adjat; Nanlohy, Martha Magdalena

    2018-01-01

    The characteristic of small to medium size islands is the limited amount of natural resources for electric generation. Presently the needs of energy in Maluku Province are supplied by the diesel generation units. The electricity distributes through an isolated grid system of each island. There are 10 separate systems in Maluku Province, namely Ambon, Namlea, Tual, Saumlaki, Mako, Piru, Bula, Masohi, Dobo and Langgur. From the geothermal point of view, this condition is suitable because the na...

  8. Characterization of Passive Flow-Actuated Microflaps Inspired by Shark Skin for Separation Control

    Science.gov (United States)

    Morris, Jackson; Devey, Sean; Lang, Amy; Hubner, Paul

    2017-11-01

    Thanks to millions of years of natural selection, sharks have evolved into quick apex predators. Previous research has proven shark skin to reduce flow separation, which would result in lower pressure drag. Mako shark skin is made up of microscopic scales on the order of 0.2 mm in size. These scales are hypothesized to be a flow control mechanism, capable of being passively actuated by reversed flow. We believe shark scales are strategically sized to interact with the lower 5 percent of the boundary layer, where reversed flow occurs near the wall. Previous wind tunnel research has shown that it is possible to passively actuate 2D flaps in the lower regions of the boundary layer. This research aims to identify reverse flow conditions that will cause small 3D flaps to actuate. Several sets of microflaps (about 4 mm in length) geometrically similar to shark scales were 3D printed. These microflaps were tested in a low-speed wind tunnel in various reverse flow conditions. Microflaps were observed to be actuated by the reversing flow and flow conditions were characterized using a hot-wire probe. These microflaps have the potential to mimic the mako shark type of flow control in air, passively actuated by reverse flow conditions. This research was supported by Boeing, the US Army, and the National Science Foundation REU program.

  9. Proceedings 2001. Networks. Section 3. Book 4

    International Nuclear Information System (INIS)

    Shukleva, Eva; Taleski, Rubin

    2001-01-01

    The holding of this Symposium was initiated by MAKO CIGRE - Macedonian Committee on Large High Voltage Systems, in compliance with its determination to raise competent discussions on current issues. The 3 sections of the conference were entitled: (1) power plants facilities, (2) power transmission lines, (3) networks. The forth volume includes the following topics: STK 36 - electromagnetic compatibility; STK 37 - planning and development of the power systems; STK 38 - power systems analysis and STK 39 - power systems control. Papers relevant to INIS are indexed separately

  10. Captura de tiburones en la región noroccidental de Cuba

    Directory of Open Access Journals (Sweden)

    Consuelo Aguilar

    2014-07-01

    Full Text Available Los tiburones han sido una importante fuente de alimento e ingresos en Cuba. A pesar de esto, es muy escasa la información sobre este grupo y, en las últimas décadas, no han sido objeto de una investigación organizada. De octubre 2009 a junio 2011 se recolectaron datos biológicos (229 tiburones examinados y pesqueros en cuatro sitios de desembarque de la región noroccidental de Cuba. En esta región, los tiburones son capturados en pesquerías comerciales multiespecíficas en la plataforma insular y de manera incidental en pesquerías deportivas de corto radio de acción durante la captura de grandes especies pelágicas de mar abierto. Se registró un total de 17 especies; seis en pesca comercial, dominada por Carcharhinus perezii, Sphyrna mokarran y Carcharhinus leucas, y 14 en pesca deportiva (artesanal de pequeña escala, no propiamente recreacional, dominada por Isurus oxyrinchus, Isurus paucus, Carcharhinus longimanus, Carcharhinus falciformis, Galeocerdo cuvier y Prionace glauca. La CPUE mensual en las pesquerías deportivas, varió de 0,43 a 4,44 tiburones capturados por diez viajes de pesca. La mayoría de los tiburones oceánicos capturados en las pesquerías deportivas son especies altamente migratorias y sus poblaciones muestran gran conectividad ecológica en el Golfo de México y aguas adyacentes. Este hecho y la presencia de una gran proporción de individuos de C. longimanus y C. falciformis por debajo de la longitud de madurez, son resultados que deben ser considerados en los planes regionales de conservación y uso racional de los tiburones.

  11. AutoWIG: automatic generation of python bindings for C++ libraries

    Directory of Open Access Journals (Sweden)

    Pierre Fernique

    2018-04-01

    Full Text Available Most of Python and R scientific packages incorporate compiled scientific libraries to speed up the code and reuse legacy libraries. While several semi-automatic solutions exist to wrap these compiled libraries, the process of wrapping a large library is cumbersome and time consuming. In this paper, we introduce AutoWIG, a Python package that wraps automatically compiled libraries into high-level languages using LLVM/Clang technologies and the Mako templating engine. Our approach is automatic, extensible, and applies to complex C++ libraries, composed of thousands of classes or incorporating modern meta-programming constructs.

  12. Diversity of dermal denticle structure in sharks: Skin surface roughness and three-dimensional morphology.

    Science.gov (United States)

    Ankhelyi, Madeleine V; Wainwright, Dylan K; Lauder, George V

    2018-05-29

    Shark skin is covered with numerous placoid scales or dermal denticles. While previous research has used scanning electron microscopy and histology to demonstrate that denticles vary both around the body of a shark and among species, no previous study has quantified three-dimensional (3D) denticle structure and surface roughness to provide a quantitative analysis of skin surface texture. We quantified differences in denticle shape and size on the skin of three individual smooth dogfish sharks (Mustelus canis) using micro-CT scanning, gel-based surface profilometry, and histology. On each smooth dogfish, we imaged between 8 and 20 distinct areas on the body and fins, and obtained further comparative skin surface data from leopard, Atlantic sharpnose, shortfin mako, spiny dogfish, gulper, angel, and white sharks. We generated 3D images of individual denticles and measured denticle volume, surface area, and crown angle from the micro-CT scans. Surface profilometry was used to quantify metrology variables such as roughness, skew, kurtosis, and the height and spacing of surface features. These measurements confirmed that denticles on different body areas of smooth dogfish varied widely in size, shape, and spacing. Denticles near the snout are smooth, paver-like, and large relative to denticles on the body. Body denticles on smooth dogfish generally have between one and three distinct ridges, a diamond-like surface shape, and a dorsoventral gradient in spacing and roughness. Ridges were spaced on average 56 µm apart, and had a mean height of 6.5 µm, comparable to denticles from shortfin mako sharks, and with narrower spacing and lower heights than other species measured. We observed considerable variation in denticle structure among regions on the pectoral, dorsal, and caudal fins, including a leading-to-trailing edge gradient in roughness for each region. Surface roughness in smooth dogfish varied around the body from 3 to 42 microns. © 2018 Wiley Periodicals, Inc.

  13. Future Climate Change Impacts on Streamflows of Two Main West Africa River Basins: Senegal and Gambia

    Directory of Open Access Journals (Sweden)

    Ansoumana Bodian

    2018-03-01

    Full Text Available This research investigated the effect of climate change on the two main river basins of Senegal in West Africa: the Senegal and Gambia River Basins. We used downscaled projected future rainfall and potential evapotranspiration based on projected temperature from six General Circulation Models (CanESM2, CNRM, CSIRO, HadGEM2-CC, HadGEM2-ES, and MIROC5 and two scenarios (RCP4.5 and RCP8.5 to force the GR4J model. The GR4J model was calibrated and validated using observed daily rainfall, potential evapotranspiration from observed daily temperature, and streamflow data. For the cross-validation, two periods for each river basin were considered: 1961–1982 and 1983–2004 for the Senegal River Basin at Bafing Makana, and 1969–1985 and 1986–2000 for the Gambia River Basin at Mako. Model efficiency is evaluated using a multi-criteria function (Fagg which aggregates Nash and Sutcliffe criteria, cumulative volume error, and mean volume error. Alternating periods of simulation for calibration and validation were used. This process allows us to choose the parameters that best reflect the rainfall-runoff relationship. Once the model was calibrated and validated, we simulated streamflow at Bafing Makana and Mako stations in the near future at a daily scale. The characteristic flow rates were calculated to evaluate their possible evolution under the projected climate scenarios at the 2050 horizon. For the near future (2050 horizon, compared to the 1971–2000 reference period, results showed that for both river basins, multi-model ensemble predicted a decrease of annual streamflow from 8% (Senegal River Basin to 22% (Gambia River Basin under the RCP4.5 scenario. Under the RCP8.5 scenario, the decrease is more pronounced: 16% (Senegal River Basin and 26% (Gambia River Basin. The Gambia River Basin will be more affected by the climate change.

  14. Total mercury in sharks along the southern Brazilian Coast Mercúrio total em tubarões capturados na costa brasileira

    Directory of Open Access Journals (Sweden)

    E.T. Mársico

    2007-12-01

    Full Text Available Pesquisou-se a concentração de mercúrio total na porção muscular de 39 exemplares de tubarões de três diferentes espécies Prionace glauca, Isurus oxyrhynchus, Sphyrna zygaena, capturados na costa sul do Brasil, Santa Catarina. O teor de mercúrio foi determinado por espectrofotometria de absorção atômica por vapor frio. Observou-se ampla variação na concentração de mercúrio total com valor individual máximo excedendo o limite estabelecido pela legislação brasileira, de 1.0µg.g-1 em um exemplar fêmea de P. glauca. Nessa espécie, a concentração de Hg-total aumentou proporcionalmente ao comprimento total (r=0,62; P<0,0001. Não foi evidenciada diferença estatisticamente significativa entre exemplares fêmeas e machos.

  15. Megalodon, mako shark and planktonic foraminifera from the continental shelf off Portugal and their age

    OpenAIRE

    ANTUNES, M.; LEGOINHA, P.; BALBINO, A.

    2015-01-01

    Turbidite fragments collected by a fishing net off the central Portuguese coast (Peniche) present some fossils. The matrix is phosphatized and iron-rich with small quantities of manganese, zinc and copper. The occurrence of Megaselachus megalodon most probably excludes an age older than Middle Miocene. Its very advanced evolution stage is consistent with a Pliocene age. Based on planktonic foraminifera in depressions of cetacean skulls recovered in the same way, from the same area...

  16. Facile analysis of contents and compositions of the chondroitin sulfate/dermatan sulfate hybrid chain in shark and ray tissues.

    Science.gov (United States)

    Takeda, Naoko; Horai, Sawako; Tamura, Jun-ichi

    2016-04-07

    The chondroitin sulfate (CS)/dermatan sulfate (DS) hybrid chain was extracted from specific tissues of several kinds of sharks and rays. The contents and sulfation patterns of the CS/DS hybrid chain were precisely analyzed by digestion with chondroitinases ABC and AC. All samples predominantly contained the A- and C-units. Furthermore, all samples characteristically contained the D-unit. Species-specific differences were observed in the contents of the CS/DS hybrid chain, which were the highest in Mako and Blue sharks and Sharpspine skates, but were lower in Hammerhead sharks. Marked differences were observed in the ratio of the C-unit/A-unit between sharks and rays. The contents of the CS/DS hybrid chain and the ratio of the C-unit/A-unit may be related to an oxidative stress-decreasing ability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Husbandry Emissions at the Sub-Facility Scale by Fused Mobile Surface In Situ and Airborne Remote Sensing

    Science.gov (United States)

    Leifer, I.; Melton, C.; Tratt, D. M.; Hall, J. L.; Buckland, K. N.; Frash, J.; Leen, J. B.; Lundquist, T.; Vigil, S. A.

    2017-12-01

    Husbandry methane (CH4) and ammonia (NH3) are strong climate and air pollution drivers. Husbandry emission factors have significant uncertainty and can differ from lab estimates as real-world practices affect emissions including where and how husbandry activities occur, their spatial and temporal relationship to micro-climate (winds, temperature, insolation, rain, and lagoon levels, which vary diurnally and seasonally), and animal care. Research dairies provide a unique opportunity to combine insights on sub-facility scale emissions to identify best practices. Two approaches with significant promise for quantifying husbandry emissions are airborne remote sensing and mobile in situ trace gas with meteorological measurements. Both capture snapshot data to allow deconvolution of temporal and spatial variability, which challenges stationary measurements, while also capturing micro-scale processes, allowing connection of real-world practices to emissions. Mobile in situ concentration data on trace gases and meteorology were collected by AMOG (AutoMObile trace Gas) Surveyor on 10 days spanning 31 months at the California Polytechnic State University Research Dairy, San Luis Obispo, CA. AMOG Surveyor is a commuter vehicle modified for atmospheric science. CH4, NH3, H2O, COS, CO, CO2, H2S, O3, NO, NO2, SO2, NOX, solar spectra, temperature, and winds were measured. The airborne hyperspectral thermal infrared sensor, Mako, collected data on 28 Sept. 2015. Research dairies allow combining insights on sub-facility scale emissions to identify best practices holistically - i.e., considering multiple trace gases. In situ data were collected while transecting plumes, approximately orthogonal to winds. Emission strength and source location were estimated by Gaussian plume inversion, validated by airborne data. Good agreement was found on source strength and location at meter length-scales. Data revealed different activities produced unique emissions with distinct trace gas

  18. Early Pliocene fishes (Chondrichthyes, Osteichthyes) from Gran Canaria and Fuerteventura (Canary Islands, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Betancort, J.F.; Lomoschitz, A.; Meco, J.

    2016-07-01

    Fossil fish teeth are contained in marine deposits dated at ca 4.8 Ma found on the islands of Gran Canaria and Fuerteventura (Canary Islands, Spain). These islands, situated in the North Atlantic Subtropical Gyre, can be considered a mid-way stopover point between the Caribbean Sea, with the Central American Seaway about to close in this epoch, and the Mediterranean, in the first stage of its post-Messinian Gibraltar Seaway period. Accordingly, there existed extensive pantropical communication, particularly for nektonic animals capable of travelling large distances. In this paper, we present a number of fossil fishes, most of which are identified for the first time on the basis of their teeth: the Chondrichthyes species Carcharocles megalodon, Parotodus benedeni, Cosmopolitodus hastalis, Isurus oxyrinchus, Carcharias cf. acutissima, Carcharhinus cf. leucas, Carcharhinus cf. priscus, Galeocerdo cf. aduncus, and the Osteichthyes species Archosargus cinctus, Labrodon pavimentatum, and Diodon scillae. Coincidences are observed between these ichthyofauna and specimens found in the Azores Islands, the Pacific coast of America and the Mediterranean Sea. (Author)

  19. Early Pliocene fishes (Chondrichthyes, Osteichthyes from Gran Canaria and Fuerteventura (Canary Islands, Spain

    Directory of Open Access Journals (Sweden)

    J. F. Betancort

    2016-11-01

    Full Text Available Fossil fish teeth are contained in marine deposits dated at ca 4.8 Ma found on the islands of Gran Canaria and Fuerteventura (Canary Islands, Spain. These islands, situated in the North Atlantic Subtropical Gyre, can be considered a mid-way stopover point between the Caribbean Sea, with the Central American Seaway about to close in this epoch, and the Mediterranean, in the first stage of its post-Messinian Gibraltar Seaway period. Accordingly, there existed extensive pantropical communication, particularly for nektonic animals capable of travelling large distances. In this paper, we present a number of fossil fishes, most of which are identified for the first time on the basis of their teeth: the Chondrichthyes species Carcharocles megalodon, Parotodus benedeni, Cosmopolitodus hastalis, Isurus oxyrinchus, Carcharias cf. acutissima, Carcharhinus cf. leucas, Carcharhinus cf. priscus, Galeocerdo cf. aduncus, and the Osteichthyes species Archosargus cinctus, Labrodon pavimentatum, and Diodon scillae. Coincidences are observed between these ichthyofauna and specimens found in the Azores Islands, the Pacific coast of America and the Mediterranean Sea.

  20. DNA barcode identification of commercial fish sold in Mexican markets.

    Science.gov (United States)

    Sarmiento-Camacho, Stephanie; Valdez-Moreno, Martha

    2018-04-24

    The substitution of high-value fish species for those of lower value is common practice. Although numerous studies have addressed this issue, few have been conducted in Mexico. In this study, we sought to identify fresh fillets of fish, sharks, and rays using DNA barcodes. We analyzed material from "La Viga" in Mexico City, and other markets located on the Gulf and Caribbean coasts of Mexico. From 134 samples, we obtained sequences from 129, identified to 9 orders, 28 families, 38 genera, and 44 species. The most common species were Seriola dumerili, Pangasianodon hypophthalmus, Carcharhinus falciformis, Carcharhinus brevipinna, and Hypanus americanus. Pangasianodon hypophthalmus was most commonly used as a substitute for higher-value species. The substitution rate was 18% of the total. A review of the conservation status of the specimens identified against the IUNC list enabled us to establish that some species marketed in Mexico are threatened: Makaira nigricans, Lachnolaimus maximus, Hyporthodus flavolimbatus, and Isurus oxyrinchus are classified as vulnerable; Lopholatilus chamaeleonticeps and Sphyrna lewini are endangered; and the status of Hyporthodus nigritus is critical. These results will demonstrate to the Mexican authorities that DNA barcoding is a reliable tool for species identification, even when morphological identification is difficult or impossible.

  1. Mid-Atlantic elasmobranchs: Suitable metal scouts?

    International Nuclear Information System (INIS)

    Torres, Paulo; Tristão da Cunha, Regina; Rodrigues, Armindo dos Santos

    2017-01-01

    Heavy metals are a hazard to marine fauna and human health. In this study we assess stable isotopes and metal content in Prionace glauca and Isurus oxyrinchus and analyse these results within and among other species and across regions and geographical areas. Also, we evaluate their suitability, together with Raja clavata and Galeorhinus galeus, as Mid-Atlantic bioindicators. Prionace glauca and I. oxyrinchus shared the same trophic level in a pelagic food web and did not present significant differences between genders or metals, except for As. Arsenic and Hg accumulated while Cd and Pb were not detected. One I. oxyrinchus presented Hg values above regulatory limits. A high Hg exposure was associated with I. oxyrinchus since its maximum weekly intake was exceeded. Elasmobranchs can be used as metal sentinels, each presenting different key features which defines a good marine bioindicator, allowing long-term monitoring at different temporal and spatial scales. - Highlights: • We analysed P. glauca and I. oxyrinchus muscle from Mid-Atlantic. • We determined stable isotopes, trophic ecology and heavy metal content. • Results reflect bioaccumulation for As and Hg. • Oxyrinchus already presented Hg values above regulatory limits. • Mid-Atlantic elasmobranchs appear to be effective metal bioindicators.

  2. Convergent evolution in mechanical design of lamnid sharks and tunas.

    Science.gov (United States)

    Donley, Jeanine M; Sepulveda, Chugey A; Konstantinidis, Peter; Gemballa, Sven; Shadwick, Robert E

    2004-05-06

    The evolution of 'thunniform' body shapes in several different groups of vertebrates, including whales, ichthyosaurs and several species of large pelagic fishes supports the view that physical and hydromechanical demands provided important selection pressures to optimize body design for locomotion during vertebrate evolution. Recognition of morphological similarities between lamnid sharks (the most well known being the great white and the mako) and tunas has led to a general expectation that they also have converged in their functional design; however, no quantitative data exist on the mechanical performance of the locomotor system in lamnid sharks. Here we examine the swimming kinematics, in vivo muscle dynamics and functional morphology of the force-transmission system in a lamnid shark, and show that the evolutionary convergence in body shape and mechanical design between the distantly related lamnids and tunas is much more than skin deep; it extends to the depths of the myotendinous architecture and the mechanical basis for propulsive movements. We demonstrate that not only have lamnids and tunas converged to a much greater extent than previously known, but they have also developed morphological and functional adaptations in their locomotor systems that are unlike virtually all other fishes.

  3. [Trophic niche partitioning of pelagic sharks in Central Eastern Pacific inferred from stable isotope analysis.

    Science.gov (United States)

    Li, Yun Kai; Gao, Xiao di; Wang, Lin Yu; Fang, Lin

    2018-01-01

    As the apex predators of the open ocean ecosystems, pelagic sharks play important roles in stabilizing the marine food web through top-down control. Stable isotope analysis is a powerful tool to investigate the feeding ecology. The carbon and nitrogen isotope ratios can be used to trace food source and evaluate the trophic position of marine organisms. In this study, the isotope values of 130 pelagic sharks from 8 species in Central Eastern Pacific were analyzed and their trophic position and niche were calculated to compare the intra/inter-specific resource partitioning in the Central Eastern Pacific ecosystem. The results exhibited significant differences in both carbon and nitrogen isotope values among the shark species. The trophic levels ranged from 4.3 to 5.4 in the Central Eastern Pacific shark community. The trophic niche of blue sharks and shortfin mako sharks showed no overlap with the other shark species, exhibiting unique ecological roles in the open ocean food web. These data highlighted the diverse roles among pelagic sharks, supporting previous findings that this species is not trophically redundant and the trophic niche of pelagic sharks can not be simply replaced by those of other top predator species.

  4. A WELL PRESERVED SKELETON OF THE FOSSIL SHARK COSMOPOLITODUS HASTALIS FROM THE LATE MIOCENE OF PERU, FEATURING FISH REMAINS AS FOSSILIZED STOMACH CONTENTS

    Directory of Open Access Journals (Sweden)

    ALBERTO COLLARETA

    2017-01-01

    Full Text Available Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru. Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus. Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation.

  5. The geothermal potentials for electric development in Maluku Province

    Directory of Open Access Journals (Sweden)

    Vijaya Isnaniawardhani

    2018-03-01

    Full Text Available The characteristic of small to medium size islands is the limited amount of natural resources for electric generation. Presently the needs of energy in Maluku Province are supplied by the diesel generation units. The electricity distributes through an isolated grid system of each island. There are 10 separate systems in Maluku Province, namely Ambon, Namlea, Tual, Saumlaki, Mako, Piru, Bula, Masohi, Dobo and Langgur. From the geothermal point of view, this condition is suitable because the nature of the generation is small to medium and the locations are dispersed. The geological condition of Maluku Province is conducive for the formation of geothermal resources. The advanced utilization of geothermal energy in Maluku Province is in Tulehu located about 8 kilometers NE of Ambon. It is expected that 60 MW electric will be produced at the first stage in 2019. A total of 100 MW resources were estimated. Other places of geothermal potentials are Lauke and Tawen both located in Ambon Island with the potentials of 25 MW respectively. In Oma Haruku, Saparua and Nusa Laut the geothermal potentials were estimated to be 25 MW each. The total amount of geothermal energy in Maluku Province is thus, 225 MW which will contribute significantly to the needs of projected 184 MW in the year 2025.

  6. Reversing flow causes passive shark scale actuation in a separating turbulent boundary layer

    Science.gov (United States)

    Lang, Amy; Gemmell, Bradford; Motta, Phil; Habegger, Laura; Du Clos, Kevin; Devey, Sean; Stanley, Caleb; Santos, Leo

    2017-11-01

    Control of flow separation by shortfin mako skin in experiments has been demonstrated, but the mechanism is still poorly understood yet must be to some extent Re independent. The hypothesized mechanisms inherent in the shark skin for controlling flow separation are: (1) the scales, which are capable of being bristled only by reversing flow, inhibit flow reversal events from further development into larger-scale separation and (2) the cavities formed when scales bristle induces mixing of high momentum flow towards the wall thus energizing the flow close to the surface. Two studies were carried out to measure passive scale actuation caused by reversing flow. A small flow channel induced an unsteady, wake flow over the scales prompting reversing flow events and scale actuation. To resolve the flow and scale movements simultaneously we used specialized optics at high magnification (1 mm field of view) at 50,000 fps. In another study, 3D printed models of shark scales, or microflaps (bristling capability up to 50 degrees), were set into a flat plate. Using a tripped, turbulent boundary layer grown over the long flat plate and a localized adverse pressure gradient, a separation bubble was generated within which the microflaps were placed. Passive flow actuation of both shark scales and microflaps by reversing flow was observed. Funding from Army Research Office and NSF REU site Grant.

  7. Record of Carcharocles megalodon in the Eastern Guadalquivir Basin (Upper Miocene, South Spain

    Directory of Open Access Journals (Sweden)

    Reolid, M.

    2015-12-01

    Full Text Available Tortonian diatomites of the San Felix Quarry (Porcuna, in the Eastern Guadalquivir Basin, have given isolated marine vertebrate remains that include a large shark tooth (123.96 mm from apex to the baseline of the root. The large size of the crown height (92.2 mm, the triangular shape, the broad serrated crown, the convex lingual face and flat labial face, and the robust, thick angled root determine that this specimen corresponds to Carcharocles megalodon. The symmetry with low slant shows it to be an upper anterior tooth. The total length estimated from the tooth crown height is calculated by means of different methods, and comparison is made with Carcharodon carcharias. The final inferred total length of around 11 m classifies this specimen in the upper size range of the known C. megalodon specimens. The palaeogeography of the Guadalquivir Basin close to the North Betic Strait, which connected the Atlantic Ocean to the Mediterranean Sea, favoured the interaction of the cold nutrient-rich Atlantic waters with warmer Mediterranean waters. The presence of diatomites indicates potential upwelling currents in this context, as well as high productivity favouring the presence of large vertebrates such as mysticetid whales, pinnipeds and small sharks (Isurus. These large vertebrates recorded in the Eastern Guadalquivir Basin were potential prey of C. megalodon.Las diatomitas tortonienses de la antigua Cantera de San Félix (Porcuna, Jaén, en el sector oriental de la Cuenca del Guadalquivir, han proporcionado restos aislados de vertebrados marinos entre los que destaca un gran diente de tiburón (123.96 mm desde el ápice hasta la línea basal de la raiz. La altura de la corona (92.2 mm, su forma triangular con bordes aserrados, la presencia de una cara lingual convexa y una labial plana, conjuntamente con la raíz angulosa y robusta, permiten determinar que este diente perteneció a un ejemplar de Carcharocles megalodon. La alta simetría de la pieza

  8. La pesquería de tiburones oceánicos-costeros en los litorales de Colima, Jalisco y Michoacán

    Directory of Open Access Journals (Sweden)

    Angélica Cruz

    2011-06-01

    Full Text Available La pesquería de tiburón es una de las más importantes en el Pacífico mexicano, en la actualidad no se cuentan con los datos de la composición específica de las capturas de las diferentes flotas. En el presente trabajo se describen aspectos biológicos-pesqueros de las especies de tiburón, capturadas por la flota palangrera de mediana altura del puerto de Manzanillo, en un periodo anual de abril 2006-abril 2007, los muestreos se realizaron mensualmente a bordo de estas embarcaciones. La composición de las capturas estuvo representada por nueve especies (n=1 962, de las cuales Carcharhinus falciformis (Bibron, 1839 (88.12% sostiene esta pesquería y en segundo lugar Prionace glauca (Linnaeus, 1758 (8.21%. Las especies poco frecuentes fueron Sphyrna zygaena (Linnaeus, 1758 con (1.78%, Alopias pelagicus (Nakamura, 1935 (0.82%, Carcharhinus longimanus (Poey, 1861 (0.45%, Alopias superciliosus (Lowe, 1839 (0.35%, Carcharhinus leucas (Valenciennes, 1839 (0.1%, Carcharhinus limbatus (Valenciennes, 1839 (0.1% é Isurus oxyrinchus (Rafinesque, 1810 (0.05%. La fecundidad estimada para C. falciformis fue de 3-7 crías/hembra con tallas de 30-45cm LT; 40.57+2.03cm LT y P. glauca con 5-52 crías/hembra, con tallas de 5-18.6cm LT; 11.61±0.21cm LT. Por lo tanto se asume que C. falciformis presenta un ciclo concurrente y P. glauca probablemente un ciclo bianual consecutivo.

  9. Control or involvement? Relationship between authoritative parenting style and adolescent depressive symptomatology.

    Science.gov (United States)

    Piko, B F; Balázs, M A

    2012-03-01

    Among factors predicting adolescent mood problems, certain aspects of the parent-adolescent relationship play an important role. In previous studies, children whose parents had an authoritative style of parenting reported the best behavioral and psychological outcomes. Therefore, the main goal of this paper was to investigate the role of authoritative parenting style and other family variables (negative family interactions and positive identification with parents) in adolescents' depressive symptomatology. The study was carried out in all primary and secondary schools in Mako and the surrounding region in Hungary in the spring of 2010, students of grades 7-12 (N = 2,072): 49.2% of the sample were males; 38.1% primary school pupils; and 61.9% high school students. Self-administered questionnaires contained items of measuring depressive symptoms (CDI) and parental variables beyond sociodemographics. Beyond descriptive statistics and calculation of correlation coefficients, multiple linear regression analyses were applied to detect relationships between parental variables and depressive scores by gender. Overall, our data support a negative association between authoritative parenting style and adolescent mood problems, particularly among girls. Among boys, only mother's responsiveness was a significant predictor. Among girls, father's parenting played a decisive role; not only his responsiveness but also demandingness. Interestingly, mother's demandingness went together with an elevated depressive score for girls. Prevention programs cannot guarantee success without taking into account the role of parents. Teaching positive parenting seems to be a part of these prevention programs that may include facilitating intimate yet autonomous relationships.

  10. DNA barcoding of shark meats identify species composition and CITES-listed species from the markets in Taiwan.

    Science.gov (United States)

    Liu, Shang-Yin Vanson; Chan, Chia-Ling Carynn; Lin, Oceana; Hu, Chieh-Shen; Chen, Chaolun Allen

    2013-01-01

    An increasing awareness of the vulnerability of sharks to exploitation by shark finning has contributed to a growing concern about an unsustainable shark fishery. Taiwan's fleet has the 4th largest shark catch in the world, accounting for almost 6% of the global figures. Revealing the diversity of sharks consumed by Taiwanese is important in designing conservation plans. However, fins make up less than 5% of the total body weight of a shark, and their bodies are sold as filets in the market, making it difficult or impossible to identify species using morphological traits. In the present study, we adopted a DNA barcoding technique using a 391-bp fragment of the mitochondrial cytochrome oxidase I (COI) gene to examine the diversity of shark filets and fins collected from markets and restaurants island-wide in Taiwan. Amongst the 548 tissue samples collected and sequenced, 20 major clusters were apparent by phylogenetic analyses, each of them containing individuals belonging to the same species (most with more than 95% bootstrap values), corresponding to 20 species of sharks. Additionally, Alopias pelagicus, Carcharhinus falciformis, Isurus oxyrinchus, and Prionace glauca consisted of 80% of the samples we collected, indicating that these species might be heavily consumed in Taiwan. Approximately 5% of the tissue samples used in this study were identified as species listed in CITES Appendix II, including two species of Sphyrna, C. longimanus and Carcharodon carcharias. DNA barcoding provides an alternative method for understanding shark species composition when species-specific data is unavailable. Considering the global population decline, stock assessments of Appendix II species and highly consumed species are needed to accomplish the ultimate goal of shark conservation.

  11. Scenarios of Land-Use Change in Protected Forest of Wosi Rendani Manokwari District, West Papua, Indonesia

    Directory of Open Access Journals (Sweden)

    Mahmud

    2017-04-01

    Full Text Available Protected forests have drawn international attention. This research aims to determine scenarios of land-use change in Protected Forest of Wosi Rendani (PFWR. The study was conducted using land evaluation approach to land unit, determination and alternative land use change, based on the potential and the level of threat for PFWR. The results showed that PFWR should remain as a protected forest although the total score of forest modeling was 130. This forest serves to protect soil, water, and danger from floods and landslides. This region has springs, caves, and waterfalls, which can be further developed into eco-tourism and environmental services. As a city forest, PFWR makes Manokwari's weather cooler, enhances the quality of air, reduces environmental pollution, and adds catchment areas. As a community forest, PFWR has forest plants, agricultural crops and fruits, in which people are only allowed to take flowers, fruits, and seeds they have planted. As a buffer zone, PFWR serves as a buffer to reduce population pressures on the forest area or village surrounding the area with high interaction by integrating conservation and economic interests of the surrounding community. As cultivation and settlement, PFWR has three settlements, namely Soribo, Kentestar, and Ipingoisi, 4 settlements outside PFWR namely Tanah Merah Indah, Ajoi, Buton, Mako Brimob, as well as plots of land owned by developers such as Bank Arfindo, Lumintu, Irman Jaya, and Suntari. The final scenario of the land use change in PFWR depends on the policy of local and central government

  12. La pesquería de tiburones oceánicos-costeros en los litorales de Colima, Jalisco y Michoacán

    Directory of Open Access Journals (Sweden)

    Angélica Cruz

    2011-06-01

    Full Text Available La pesquería de tiburón es una de las más importantes en el Pacífico mexicano, en la actualidad no se cuentan con los datos de la composición específica de las capturas de las diferentes flotas. En el presente trabajo se describen aspectos biológicos-pesqueros de las especies de tiburón, capturadas por la flota palangrera de mediana altura del puerto de Manzanillo, en un periodo anual de abril 2006-abril 2007, los muestreos se realizaron mensualmente a bordo de estas embarcaciones. La composición de las capturas estuvo representada por nueve especies (n=1 962, de las cuales Carcharhinus falciformis (Bibron, 1839 (88.12% sostiene esta pesquería y en segundo lugar Prionace glauca (Linnaeus, 1758 (8.21%. Las especies poco frecuentes fueron Sphyrna zygaena (Linnaeus, 1758 con (1.78%, Alopias pelagicus (Nakamura, 1935 (0.82%, Carcharhinus longimanus (Poey, 1861 (0.45%, Alopias superciliosus (Lowe, 1839 (0.35%, Carcharhinus leucas (Valenciennes, 1839 (0.1%, Carcharhinus limbatus (Valenciennes, 1839 (0.1% é Isurus oxyrinchus (Rafinesque, 1810 (0.05%. La fecundidad estimada para C. falciformis fue de 3-7 crías/hembra con tallas de 30-45cm LT; 40.57+2.03cm LT y P. glauca con 5-52 crías/hembra, con tallas de 5-18.6cm LT; 11.61±0.21cm LT. Por lo tanto se asume que C. falciformis presenta un ciclo concurrente y P. glauca probablemente un ciclo bianual consecutivo.Fishery of oceanic and coastal sharks in Colima, Jalisco and Michoacán. Shark fishery is one of the most important activities in the Mexican Pacific coast, nevertheless, there is few data available about the specific captures done by the fleet along the coast. This study describes fishery biology aspects of the shark species catched by the semi-industrial long-line fleet of Manzanillo. Monthly samplings were made on board of these vessels during an annual period from April 2006 to April 2007. Captured species composition (n=1 962 organisms was represented by nine species. The one

  13. A partial skeleton of a new lamniform mackerel shark from the Miocene of Europe

    Directory of Open Access Journals (Sweden)

    Jürgen Kriwet

    2015-12-01

    Full Text Available Cenozoic lamniform sharks are mostly represented by isolated teeth and vertebrae, whereas articulated skeletal remains are usually very scarce. Here, we describe a partial skeleton of an extinct lamniform shark consisting of 42 slightly disarticulated teeth, 49 vertebrae, and additional unidentifiable cranial and postcranial remains. The specimen originates from the Miocene mica-clay of Groß Pampau (North Germany, which is of late Langenfeldian age (= Serravallian-Tortonian boundary; middle–late Miocene. A total of 13 measurements of each tooth, as well as morphological features, were used to reconstruct the dentition of this specimen and to provide detailed taxonomic information. Additionally, the total body size and age at death were established using methodologies based on vertebral and tooth measurements and vertebral centra growth ring counts, respectively. The specimen undoubtedly represents the most complete individual of “Carcharodon (= Isurus escheri”, previously known only from a few isolated teeth. The dental pattern (e.g., marked dignathic and monognathic heterodonty patterns; only slightly labio-lingually compressed upper teeth; upper teeth slender with distally inclined or curved main cusps; massive, hook-like upper intermediate tooth; main cusps with crenulated cutting edges; lateral cusplets in teeth of all ontogenetic stages clearly separates this shark from all hitherto known Cenozoic and Recent lamnids and a new genus, Carcharomodus, consequently is introduced. Carcharomodus escheri comb. nov. is a characteristic element of late early Miocene to the Pliocene Western and Central European fish faunas. All previously identified Pacific occurrences represent a different taxon. We estimate that the specimen had a total body length of about 4 m and that it was older than 10 years and thus might have reached maturity before death, as indicated by all available evidence.

  14. DNA barcoding of shark meats identify species composition and CITES-listed species from the markets in Taiwan.

    Directory of Open Access Journals (Sweden)

    Shang-Yin Vanson Liu

    Full Text Available BACKGROUND: An increasing awareness of the vulnerability of sharks to exploitation by shark finning has contributed to a growing concern about an unsustainable shark fishery. Taiwan's fleet has the 4th largest shark catch in the world, accounting for almost 6% of the global figures. Revealing the diversity of sharks consumed by Taiwanese is important in designing conservation plans. However, fins make up less than 5% of the total body weight of a shark, and their bodies are sold as filets in the market, making it difficult or impossible to identify species using morphological traits. METHODS: In the present study, we adopted a DNA barcoding technique using a 391-bp fragment of the mitochondrial cytochrome oxidase I (COI gene to examine the diversity of shark filets and fins collected from markets and restaurants island-wide in Taiwan. RESULTS: Amongst the 548 tissue samples collected and sequenced, 20 major clusters were apparent by phylogenetic analyses, each of them containing individuals belonging to the same species (most with more than 95% bootstrap values, corresponding to 20 species of sharks. Additionally, Alopias pelagicus, Carcharhinus falciformis, Isurus oxyrinchus, and Prionace glauca consisted of 80% of the samples we collected, indicating that these species might be heavily consumed in Taiwan. Approximately 5% of the tissue samples used in this study were identified as species listed in CITES Appendix II, including two species of Sphyrna, C. longimanus and Carcharodon carcharias. CONCLUSION: DNA barcoding provides an alternative method for understanding shark species composition when species-specific data is unavailable. Considering the global population decline, stock assessments of Appendix II species and highly consumed species are needed to accomplish the ultimate goal of shark conservation.

  15. Social normative beliefs regarding cigarette smoking in Hungarian adolescents.

    Science.gov (United States)

    Page, Randy M; Piko, Bettina F; Balazs, Mate A; Struk, Tamara

    2011-10-01

    Hungary will continue to experience a high burden of disease and death from lung cancer and other tobacco-induced disease unless there is a significant reduction in youth smoking. Social factors have been found to be among the most important determinants of adolescent smoking, yet few studies have investigated social normative beliefs in Hungarian youth. The purpose of the current study was to investigate three measures of smoking normative beliefs thought to influence adolescent smoking: perceived prevalence of smoking; perceived popularity of smoking among successful/elite elements of society; and perceived disapproval by friends and family. A cross-sectional school-based survey of eighth grade (n = 258) and 12th grade (n = 288) students in Mako, Hungary was conducted to assess social normative beliefs about smoking, current smoking, ever smoking, and susceptibility to smoking. The association of the normative beliefs with the smoking behavior variables was examined through logistic regression analysis, and the underlying factor structure of the normative belief items in the current sample was determined through factor analysis. The percent of boys reporting current smoking was 40.5% in 12th grade and 27.0% in eighth grade. Among girls, the percent was 44.0% of 12th graders and 29.1% of eighth graders. Parent/peer disapproval was the most consistently associated normative belief with smoking behavior and susceptibility to smoking across both samples. Youth smoking prevention programs should consider assessing and taking into account normative beliefs and develop strategies that provide accurate information about the actual prevalence of smoking, the types of individuals who smoke, and approval/disapproval of smoking by parents and peers. © 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.

  16. [Control or involvement? Relationship between parenting style and adolescent depression].

    Science.gov (United States)

    Pikó, Bettina; Balázs, Máté Ádám

    2010-01-01

    A number of studies have pointed out that parenting style has a longstanding impact on psychological health. Besides parental/familial risk factors certain aspects of the parent-adolescent relationship may serve as a protective factor and help prevent adolescent depression such as the authoritative parenting style. The aim of the present study has been to analyze interrelationships between adolescent depressive symptomatology, authoritative parenting style, negative and positive parental links. The study was carried out on in all primary and secondary schools in Mako and the surrounding region in the spring of 2010, students of grades 7-12 (N = 2072), 49.2% of the sample were males and 50.8% females; 38.1% primary school pupils and 61.9% high school students. Self-administered questionnaires contained items of measuring depressive symptoms (CDI) and parental variables beyond sociodemographics. After descripive statistics, correlation and multiple linear regression analyses have been used to detect interrelationships. Data support the protective effect of authoritative parenting style in relation to adolescent depression, particularly among girls. Among boys, only mother's responsive behavior proved to be a protective factor. Among girls, however, both elements of the father's authoritative parenting style were decisive; not only responsiveness but also demandingness. The parenting style of the opposite-sex parent was prevailing in both sexes. Negative family interactions served as a risk factor, whereas positive parental identification was a protective factor during adolescence as well. There is a need to strengthen the role of the authoritative parenting style and to guarantee the presence of the opposite-sex parents in the adolescents' lives. Nowadays there are family-oriented interventions which put forward the effectiveness of parenting and problem-solving and aiming at harmonizing the parent-adolescent relationship.

  17. ARE: Ada Rendering Engine

    Directory of Open Access Journals (Sweden)

    Stefano Penge

    2009-10-01

    'interno dei progetti ADA e MAKO.Tra gli sviluppi previsti: il completamento della libreria per diverse DTD; la creazione di classi di livello superiori che automatizzino compiti ripetitivi (creazione di form, tabelle, etc.

  18. The Pelagics Habitat Analysis Module (PHAM): Decision Support Tools for Pelagic Fisheries

    Science.gov (United States)

    Armstrong, E. M.; Harrison, D. P.; Kiefer, D.; O'Brien, F.; Hinton, M.; Kohin, S.; Snyder, S.

    2009-12-01

    PHAM is a project funded by NASA to integrate satellite imagery and circulation models into the management of commercial and threatened pelagic species. Specifically, the project merges data from fishery surveys, and fisheries catch and effort data with satellite imagery and circulation models to define the habitat of each species. This new information on habitat will then be used to inform population distribution and models of population dynamics that are used for management. During the first year of the project, we created two prototype modules. One module, which was developed for the Inter-American Tropical Tuna Commission, is designed to help improve information available to manage the tuna fisheries of the eastern Pacific Ocean. The other module, which was developed for the Coastal Pelagics Division of the Southwest Fishery Science Center, assists management of by-catch of mako, blue, and thresher sharks along the Californian coast. Both modules were built with the EASy marine geographic information system, which provides a 4 dimensional (latitude, longitude, depth, and time) home for integration of the data. The projects currently provide tools for automated downloading and geo-referencing of satellite imagery of sea surface temperature, height, and chlorophyll concentrations; output from JPL’s ECCO2 global circulation model and its ROM California current model; and gridded data from fisheries and fishery surveys. It also provides statistical tools for defining species habitat from these and other types of environmental data. These tools include unbalanced ANOVA, EOF analysis of satellite imagery, and multivariate search routines for fitting fishery data to transforms of the environmental data. Output from the projects consists of dynamic maps of the distribution of the species that are driven by the time series of satellite imagery and output from the circulation models. It also includes relationships between environmental variables and recruitment. During

  19. Diet Composition and Trophic Ecology of Northeast Pacific Ocean Sharks.

    Science.gov (United States)

    Bizzarro, Joseph J; Carlisle, Aaron B; Smith, Wade D; Cortés, Enric

    Although there is a general perception of sharks as large pelagic, apex predators, most sharks are smaller, meso- and upper-trophic level predators that are associated with the seafloor. Among 73 shark species documented in the eastern North Pacific (ENP), less than half reach maximum lengths >200cm, and 78% occur in demersal or benthic regions of the continental shelf or slope. Most small (≤200cm) species (e.g., houndsharks) and demersal, nearshore juveniles of larger species (e.g., requiem sharks) consume small teleosts and decapod crustaceans, whereas large species in pelagic coastal and oceanic environments feed on large teleosts and squids. Several large, pelagic apex predator species occur in the ENP, but the largest species (i.e., Basking Shark, Whale Shark) consume zooplankton or small nekton. Size-based dietary variability is substantial for many species, and segregation of juvenile and adult foraging habitats also is common (e.g., Horn Shark, Shortfin Mako). Temporal dietary differences are most pronounced for temperate, nearshore species with wide size ranges, and least pronounced for smaller species in extreme latitudes and deep-water regions. Sympatric sharks often occupy various trophic positions, with resource overlap differing by space and time and some sharks serving as prey to other species. Most coastal species remain in the same general region over time and feed opportunistically on variable prey inputs (e.g., season migrations, spawning, or recruitment events), whereas pelagic, oceanic species actively seek hot spots of prey abundance that are spatiotemporally variable. The influence of sharks on ecosystem structure and regulation has been downplayed compared to that of large teleosts species with higher per capita consumption rates (e.g., tunas, billfishes). However, sharks also exert indirect influences on prey populations by causing behavioural changes that may result in restricted ranges and reduced fitness. Except for food web modelling

  20. State Performance-Based Regulation Using Multiyear Rate Plans for U.S. Electric Utilities

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Mark Newton [Pacific Economics Group Research LLC (United States); Makos, Matt [Pacific Economics Group Research LLC (United States); Deason, Jeff [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Schwartz, Lisa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-07-31

    Electric utilities today must contain costs at a time when many need to modernize aging systems and all face major changes in technologies, customer preferences and competitive pressures.Most U.S. electric utility facilities are investor-owned, subject to rate and service regulation by state public utility commissions. Regulatory systems under which these utilities operate affect their performance and ability to meet these challenges. In this business environment, multiyear rate plans have some advantages over traditional rate regulation.The report focuses on key design issues and provides case studies of the multiyear rate plan approach, applicable to both vertically integrated and restructured states. Mark Newton Lowry and Matt Makos of Pacific Energy Group Research and Jeff Deason of Berkeley Lab authored the report; Lisa Schwartz, Berkeley Lab, was project manager and technical editor.The report is aimed primarily at state utility regulators and stakeholders in the state regulatory process. The multiyear rate approach also provides ideas on how to streamline oversight of public power utilities and rural electric cooperatives for their governing boards.Two key provisions of multiyear rate plans strengthen cost containment incentives and streamline regulation: 1. Reducing frequency of rate cases, typically to every four or five years 2. Using an attrition relief mechanism to escalate rates or revenue between rate cases to address cost pressures such as inflation and growth in number of customers, independently of the utility’s own cost Better utility performance can be achieved under well-designed multiyear rate plans while achieving lower regulatory costs. Benefits can be shared between utilities and their customers. But plans can be complex and involve significant changes in the regulatory system. Designing plans that stimulate utility performance without undue risk and share benefits fairly can be challenging.This report discusses the rationale for multiyear

  1. Native Geosciences: Strengthening the Future Through Tribal Traditions

    Science.gov (United States)

    Bolman, J. R.; Quigley, I.; Douville, V.; Hollow Horn Bear, D.

    2008-12-01

    Native people have lived for millennia in distinct and unique ways in our natural sacred homelands and environments. Tribal cultures are the expression of deep understandings of geosciences shared through oral histories, language and ceremonies. Today, Native people as all people are living in a definite time of change. The developing awareness of "change" brings forth an immense opportunity to expand and elevate Native geosciences knowledge, specifically in the areas of earth, wind, fire and water. At the center of "change" is the need to balance the needs of the people with the needs of the environment. Native tradition and our inherent understanding of what is "sacred above is sacred below" is the foundation for an emerging multi-faceted approach to increasing the representation of Natives in geosciences. The approach is also a pathway to assist in Tribal language revitalization, connection of oral histories and ceremonies as well as building an intergenerational teaching/learning community. Humboldt State University, Sinte Gleska University and South Dakota School of Mines and Technology in partnership with Northern California (Hoopa, Yurok, & Karuk) and Great Plains (Lakota) Tribes have nurtured Native geosciences learning communities connected to Tribal Sacred Sites and natural resources. These sites include the Black Hills (Mato Paha, Mato Tiplia, Hinhan Kaga Paha, Mako Sica etc.), Klamath River (Ishkêesh), and Hoopa Valley (Natinixwe). Native geosciences learning is centered on the themes of earth, wind, fire and water and Native application of remote sensing technologies. Tribal Elders and Native geoscientists work collaboratively providing Native families in-field experiential intergenerational learning opportunities which invite participants to immerse themselves spiritually, intellectually, physically and emotionally in the experiences. Through this immersion and experience Native students and families strengthen the circle of our future Tribal

  2. Genome-wide identification and expression profiling reveal tissue-specific expression and differentially-regulated genes involved in gibberellin metabolism between Williams banana and its dwarf mutant.

    Science.gov (United States)

    Chen, Jingjing; Xie, Jianghui; Duan, Yajie; Hu, Huigang; Hu, Yulin; Li, Weiming

    2016-05-27

    Dwarfism is one of the most valuable traits in banana breeding because semi-dwarf cultivars show good resistance to damage by wind and rain. Moreover, these cultivars present advantages of convenient cultivation, management, and so on. We obtained a dwarf mutant '8818-1' through EMS (ethyl methane sulphonate) mutagenesis of Williams banana 8818 (Musa spp. AAA group). Our research have shown that gibberellins (GAs) content in 8818-1 false stems was significantly lower than that in its parent 8818 and the dwarf type of 8818-1 could be restored by application of exogenous GA3. Although GA exerts important impacts on the 8818-1 dwarf type, our understanding of the regulation of GA metabolism during banana dwarf mutant development remains limited. Genome-wide screening revealed 36 candidate GA metabolism genes were systematically identified for the first time; these genes included 3 MaCPS, 2 MaKS, 1 MaKO, 2 MaKAO, 10 MaGA20ox, 4 MaGA3ox, and 14 MaGA2ox genes. Phylogenetic tree and conserved protein domain analyses showed sequence conservation and divergence. GA metabolism genes exhibited tissue-specific expression patterns. Early GA biosynthesis genes were constitutively expressed but presented differential regulation in different tissues in Williams banana. GA oxidase family genes were mainly transcribed in young fruits, thus suggesting that young fruits were the most active tissue involved in GA metabolism, followed by leaves, bracts, and finally approximately mature fruits. Expression patterns between 8818 and 8818-1 revealed that MaGA20ox4, MaGA20ox5, and MaGA20ox7 of the MaGA20ox gene family and MaGA2ox7, MaGA2ox12, and MaGA2ox14 of the MaGA2ox gene family exhibited significant differential expression and high-expression levels in false stems. These genes are likely to be responsible for the regulation of GAs content in 8818-1 false stems. Overall, phylogenetic evolution, tissue specificity and differential expression analyses of GA metabolism genes can provide a

  3. An observational study of duloxetine versus SSRI monotherapy for the treatment of painful physical symptoms in Japanese patients with major depressive disorder: primary analysis

    Directory of Open Access Journals (Sweden)

    Kuga A

    2017-08-01

    Full Text Available Atsushi Kuga,1 Toshinaga Tsuji,2 Shinji Hayashi,2 Mako Matsubara,3 Shinji Fujikoshi,4 Hirofumi Tokuoka,1 Aki Yoshikawa,5 Rodrigo Escobar,6 Kazuhide Tanaka,7 Takaharu Azekawa8 1Bio Medicine, Medicines Development Unit Japan, Eli Lilly Japan K.K., Kobe, Japan; 2Medical Affairs Department, Shionogi & Co. Ltd, Osaka, Japan; 3Pharmacovigilance Department, Shionogi & Co. Ltd, Osaka, Japan; 4Statistical Science, Medicines Development Unit Japan, Eli Lilly Japan K.K., Kobe, Japan; 5Scientific Communications, Medicines Development Unit Japan, Eli Lilly Japan K.K. Kobe, Japan; 6Bio-Medicines, Eli Lilly and Company, Indianapolis, IN, USA; 7Hitsuji Clinic, Kusatsu, Japan; 8Shioiri Mental Clinic, Yokosuka, Japan Objective: The objective of this study was to assess the effectiveness of duloxetine monotherapy, in comparison with selective serotonin reuptake inhibitor (SSRI monotherapy, in the treatment of painful physical symptoms (PPS in Japanese patients with major depressive disorder (MDD in real-world clinical settings.Methods: This was a multicenter, 12-week prospective, observational study. This study enrolled MDD patients with at least moderate PPS, defined as a Brief Pain Inventory-Short Form (BPI-SF average pain score (item 5 ≥3. Patients were treated with duloxetine or SSRIs (escitalopram, sertraline, paroxetine, or fluvoxamine for 12 weeks, and PPS were assessed by BPI-SF average pain score. The primary outcome was early improvement in the BPI-SF average pain score at 4 weeks post-baseline. Results: A total of 523 patients were evaluated for treatment effectiveness (duloxetine N=273, SSRIs N=250. The difference in BPI-SF average pain score between the two groups was not statistically significant at 4 weeks post-baseline, the primary endpoint (least-squares mean change from baseline [95% confidence interval]: duloxetine,−2.8 [−3.1, −2.6]; SSRIs, −2.5 [−2.8, −2.3]; P=0.166. There was a numerical advantage for duloxetine in improvement

  4. Sailfish: A flexible multi-GPU implementation of the lattice Boltzmann method

    Science.gov (United States)

    Januszewski, M.; Kostur, M.

    2014-09-01

    We present Sailfish, an open source fluid simulation package implementing the lattice Boltzmann method (LBM) on modern Graphics Processing Units (GPUs) using CUDA/OpenCL. We take a novel approach to GPU code implementation and use run-time code generation techniques and a high level programming language (Python) to achieve state of the art performance, while allowing easy experimentation with different LBM models and tuning for various types of hardware. We discuss the general design principles of the code, scaling to multiple GPUs in a distributed environment, as well as the GPU implementation and optimization of many different LBM models, both single component (BGK, MRT, ELBM) and multicomponent (Shan-Chen, free energy). The paper also presents results of performance benchmarks spanning the last three NVIDIA GPU generations (Tesla, Fermi, Kepler), which we hope will be useful for researchers working with this type of hardware and similar codes. Catalogue identifier: AETA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETA_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU Lesser General Public License, version 3 No. of lines in distributed program, including test data, etc.: 225864 No. of bytes in distributed program, including test data, etc.: 46861049 Distribution format: tar.gz Programming language: Python, CUDA C, OpenCL. Computer: Any with an OpenCL or CUDA-compliant GPU. Operating system: No limits (tested on Linux and Mac OS X). RAM: Hundreds of megabytes to tens of gigabytes for typical cases. Classification: 12, 6.5. External routines: PyCUDA/PyOpenCL, Numpy, Mako, ZeroMQ (for multi-GPU simulations), scipy, sympy Nature of problem: GPU-accelerated simulation of single- and multi-component fluid flows. Solution method: A wide range of relaxation models (LBGK, MRT, regularized LB, ELBM, Shan-Chen, free energy, free surface) and boundary conditions within the lattice

  5. Integrating geoscience and Native American experiences through a multi-state geoscience field trip for high school students

    Science.gov (United States)

    Kelso, P. R.; Brown, L. M.; Spencer, M.; Sabatine, S.; Goetz, E. R.

    2012-12-01

    Lake Superior State University (LSSU) developed the GRANITE (Geological Reasoning And Natives Investigating The Earth) to engage high school students in the geosciences. The GRANITE program's target audience is Native American high school students and other populations underrepresented in the geosciences. Through the GRANITE program students undertake a variety of field and laboratory geosciences activities that culminates in a two week summer geoscience field experience during which they travel from Michigan to Wyoming. The sites students visit were selected because of their interesting and diverse geologic features and because in many cases they have special significance to Native American communities. Examples of the processes and localities studied by GRANITE students include igneous processes at Bear Butte, SD (Mato Paha) and Devil's Tower, WY (Mato Tipila); sedimentary processes in the Badlands, SD (Mako Sica) and Black Hills, SD (Paha Sapa); karst processes at Wind Cave, SD (Wasun Niye) and Vore Buffalo Jump; structural processes at Van Hise rock, WI and Dillon normal fault Badlands, SD; hydrologic and laucustrine processes along the Great Lakes and at the Fond du Lac Reservation, MN; fluvial processes along the Mississippi and Missouri rivers; geologic resources at the Homestake Mine, SD and Champion Mine, MI; and metamorphic processes at Pipestone, MN and Baraboo, WI. Through the GRANITE experience students develop an understanding of how geoscience is an important part of their lives, their communities and the world around them. The GRANITE program also promotes each student's growth and confidence to attend college and stresses the importance of taking challenging math and science courses in high school. Geoscience career opportunities are discussed at specific geologic localities and through general discussions. GRANITE students learn geosciences concepts and their application to Native communities and society in general through activities and

  6. Morphology and evolution of the jaw suspension in lamniform sharks.

    Science.gov (United States)

    Wilga, C D

    2005-07-01

    both of the insertion points. The original ventral preorbitalis division now inserts onto the connective tissue surrounding the mid-region of the upper jaw, while the new dorsal preorbitalis division inserts onto the surrounding connective tissue and skin at a more posterior position on the upper jaw. The retractor muscle of the jaws, the levator hyomandibularis, has also been modified during the evolution of lamniform sharks. In most sharks, including basal lamniforms, the levator hyomandibularis inserts onto the hyomandibula and functions to retract the jaws after protrusion. In alopid and lamnid sharks the levator hyomandibularis inserts primarily onto the upper and lower jaws around the jaw joint and is a more direct route for retracting the jaws. Thus, there has been at least one instance of character loss (ethmopalatine ligament), acquisition (palatonasal ligament), subdivision (preorbitalis), and modification (ventral preorbitalis, dorsal preorbitalis, and levator hyomandibularis) in the ligaments and muscles associated with the jaw suspension and jaw protrusion mechanism in lamniform sharks. While derived lamniform sharks (Lamna nasus, Carcharodon carcharius, and Isurus oxyrinchus) lost the ancestral passive lateral support of the ethmoid articulation of the upper jaw, they simultaneously acquired muscular support by way of the levator hyomandibularis, which provides a dynamic mechanism for lateral support. The evolution of multiple divisions of preorbitalis insertions onto the palatoquadrate and modification of the levator hyomandibularis insertion directly onto the jaws provides an active mechanism for multiple protractions and retractions of the upper jaw, which is advantageous in those sharks that gouge or saw pieces from large oversized prey items.

  7. Drag Reduction by Riblets & Sharkskin Denticles: A Numerical Study

    Science.gov (United States)

    Boomsma, Aaron

    Riblet films are a passive method of turbulent boundary layer control that can reduce viscous drag. They have been studied with great detail for over 30 years. Although common riblet applications include flows with Adverse Pressure Gradients (APG), nearly all research thus far has been performed in channel flows. Recent research has provided motivation to study riblets in more complicated turbulent flows with claims that riblet drag reduction can double in mild APG common to airfoils at moderate angles of attack. Therefore, in this study, we compare drag reduction by scalloped riblet films between riblets in a zero pressure gradient and those in a mild APG using high-resolution large eddy simulations. In order to gain a fundamental understanding of the relationship between drag reduction and pressure gradient, we simulated several different riblet sizes that encompassed a broad range of s + (riblet width in wall units), similarly to many experimental studies. We found that there was only a slight improvement in drag reduction for riblets in the mild APG. We also observed that peak values of streamwise turbulence intensity, turbulent kinetic energy, and streamwise vorticity scale with riblet width. Primary Reynolds shear stresses and turbulence kinetic energy production however scale with the ability of the riblet to reduce skin-friction. Another turbulent roughness of similar shape and size to riblets is sharkskin. The hydrodynamic function of sharkskin has been under investigation for the past 30 years. Current literature conflicts on whether sharkskin is able to reduce skin friction similarly to riblets. To contribute insights toward reconciling these conflicting views, Direct Numerical Simulations (DNS) are carried out to obtain detailed flow fields around realistic denticles. A sharp interface immersed boundary method is employed to simulate two arrangements of actual sharkskin denticles (from Isurus oxyrinchus) in a turbulent boundary layer at Retau ≈ 180