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Sample records for lemon shark negaprion

  1. Social learning in juvenile lemon sharks, Negaprion brevirostris.

    Science.gov (United States)

    Guttridge, Tristan L; van Dijk, Sander; Stamhuis, Eize J; Krause, Jens; Gruber, Samuel H; Brown, Culum

    2013-01-01

    Social learning is taxonomically widespread and can provide distinct behavioural advantages, such as in finding food or avoiding predators more efficiently. Although extensively studied in bony fishes, no such empirical evidence exists for cartilaginous fishes. Our aim in this study was to experimentally investigate the social learning capabilities of juvenile lemon sharks, Negaprion brevirostris. We designed a novel food task, where sharks were required to enter a start zone and subsequently make physical contact with a target in order to receive a food reward. Naive sharks were then able to interact with and observe (a) pre-trained sharks, that is, 'demonstrators', or (b) sharks with no previous experience, that is, 'sham demonstrators'. On completion, observer sharks were then isolated and tested individually in a similar task. During the exposure phase observers paired with 'demonstrator' sharks performed a greater number of task-related behaviours and made significantly more transitions from the start zone to the target, than observers paired with 'sham demonstrators'. When tested in isolation, observers previously paired with 'demonstrator' sharks completed a greater number of trials and made contact with the target significantly more often than observers previously paired with 'sham demonstrators'. Such experience also tended to result in faster overall task performance. These results indicate that juvenile lemon sharks, like numerous other animals, are capable of using socially derived information to learn about novel features in their environment. The results likely have important implications for behavioural processes, ecotourism and fisheries.

  2. Increases in arterial blood oxygen during exercise in the lemon shark (Negaprion brevirostris)

    DEFF Research Database (Denmark)

    BUSHNELL, PG; LUTZ, PL; STEFFENSEN, JF

    1982-01-01

    Polyethylene cannulae were implanted in pre- and post-branchial blood vessels allowing nonstressful blood sampling over a variety of activity ranges in an active tropical elasmobranch, the lemon shark (Negaprion brevirostris). TheP 50 was found to be 11.8 Torr at 24°C and pH of 7.7. A Bohr shift...

  3. Monogenoid infection of neonatal and older juvenile lemon sharks, Negaprion brevirostris (Carcharhinidae), in a shark nursery.

    Science.gov (United States)

    Young, Joy M; Frasca, Salvatore; Gruber, Samuel H; Benz, George W

    2013-12-01

    Fifty lemon sharks, Negaprion brevirostris , were captured in a shallow, mangrove-fringed shark nursery at Bimini, Bahamas and examined for the presence of skin-dwelling ectoparasitic monogenoids (Monogenoidea). Sixteen sharks were infected by Dermophthirius nigrellii (Microbothriidae); the youngest host was estimated to be 3- to 4-wk-old. Infection prevalence, mean intensity, and median intensity (0.32, 2.63, and 2.0, respectively, for all sharks) were not significantly different between neonates (estimated ages 3- to 10-wk-old) and non-neonatal juveniles (estimated ages 1- to 4-yr-old), suggesting that soon after parturition lemon sharks acquire infection levels of D. nigrellii matching those of juvenile conspecifics. Monogenoids were only found on the trailing portion of the first and second dorsal fins and upper lobe of the caudal fin. The prevalence of D. nigrellii was highest on the first dorsal fin; however, the mean and median intensities of D. nigrellii were similar between fins in all but 1 case. These results raise important husbandry implications regarding the practice of preferentially seeking neonatal and other small lemon sharks for captivity.

  4. The energetic, physiological, and behavioral response of lemon sharks (Negaprion brevirostris) to simulated longline capture.

    Science.gov (United States)

    Bouyoucos, Ian A; Suski, Cory D; Mandelman, John W; Brooks, Edward J

    2017-05-01

    Commercial fisheries bycatch is a considerable threat to elasmobranch population recovery, and techniques to mitigate sub-lethal consequences can be improved with data on the energetic, physiological, and behavioral response of individuals to capture. This study sought to estimate the effects of simulated longline capture on the behavior, energy use, and physiological stress of juvenile lemon sharks (Negaprion brevirostris). Captive sharks equipped with acceleration biologgers were subjected to 1h of simulated longline capture. Swimming behaviors were identified from acceleration data using a machine-learning algorithm, energetic costs were estimated using accelerometer-calibrated relationships and respirometry, and physiological stress was quantified with point-of-care blood analyzers. During capture, sharks exhibited nine-fold increases in the frequency of burst swimming, 98% reductions in resting, and swam as often as unrestrained sharks. Aerobic metabolic rates during capture were 8% higher than for unrestrained sharks, and accounted for a 57.7% increase in activity costs when excess post-exercise oxygen consumption was included. Lastly, sharks exhibited significant increases in blood lactate and glucose, but no change in blood pH after 1h of capture. Therefore, these results provide preliminary insight into the behavioral and energetic responses of sharks to capture, and have implications for mitigating sub-lethal consequences of capture for sharks as commercial longline bycatch. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Regional-scale migrations and habitat use of juvenile lemon sharks (Negaprion brevirostris) in the US South Atlantic.

    Science.gov (United States)

    Reyier, Eric A; Franks, Bryan R; Chapman, Demian D; Scheidt, Douglas M; Stolen, Eric D; Gruber, Samuel H

    2014-01-01

    Resolving the geographic extent and timing of coastal shark migrations, as well as their environmental cues, is essential for refining shark management strategies in anticipation of increasing anthropogenic stressors to coastal ecosystems. We employed a regional-scale passive acoustic telemetry array encompassing 300 km of the east Florida coast to assess what factors influence site fidelity of juvenile lemon sharks (Negaprion brevirostris) to an exposed coastal nursery at Cape Canaveral, and to document the timing and rate of their seasonal migrations. Movements of 54 juvenile lemon sharks were monitored for three years with individuals tracked for up to 751 days. While most sharks demonstrated site fidelity to the Cape Canaveral region December through February under typical winter water temperatures, historically extreme declines in ocean temperature were accompanied by rapid and often temporary, southward displacements of up to 190 km along the Florida east coast. From late February through April each year, most sharks initiated a northward migration at speeds of up to 64 km day(-1) with several individuals then detected in compatible estuarine telemetry arrays in Georgia and South Carolina up to 472 km from release locations. Nineteen sharks returned for a second or even third consecutive winter, thus demonstrating strong seasonal philopatry to the Cape Canaveral region. The long distance movements and habitat associations of immature lemon sharks along the US southeast coast contrast sharply with the natal site fidelity observed in this species at other sites in the western Atlantic Ocean. These findings validate the existing multi-state management strategies now in place. Results also affirm the value of collaborative passive arrays for resolving seasonal movements and habitat preferences of migratory coastal shark species not easily studied with other tagging techniques.

  6. The behaviour and recovery of juvenile lemon sharks Negaprion brevirostris in response to external accelerometer tag attachment.

    Science.gov (United States)

    Bullock, R W; Guttridge, T L; Cowx, I G; Elliott, M; Gruber, S H

    2015-12-01

    Behavioural responses of lemon sharks Negaprion brevirostris to a fin-mounted tag package (CEFAS G6A tri-axial accelerometer with epoxied Sonotronics PT4 acoustic transmitter) were measured in a controlled captive environment (n = 10, total length, LT range 80-140 cm) and in free-ranging sharks upon release (n = 7, LT range 100-160 cm). No changes were detected in behaviour (i.e. swimming speed, tailbeat frequency, time spent resting and frequency of chafing) between control and tagged captive shark trials, suggesting that the tag package itself does not alter behaviour. In the free-ranging trials, an initial period of elevated swimming activity was found in all individuals (represented by overall dynamic body acceleration). Negaprion brevirostris, however, appeared to recover quickly, returning to a steady swimming state between 2 and 35 min after release. Post-release tracking found that all sharks swim immediately for the shoreline and remain within 100 m of shore for prolonged periods. Hence, although N. brevirostris are capable of quick adaptation to stressors and demonstrate rapid recovery in terms of activity, tracking data suggest that they may modify their spatial use patterns post release. This research is important in separating deviation in behaviour due to environmental stressors from artefacts caused by experimental techniques. © 2015 The Fisheries Society of the British Isles.

  7. Aerial Survey as a Tool to Estimate Abundance and Describe Distribution of a Carcharhinid Species, the Lemon Shark, Negaprion brevirostris

    Directory of Open Access Journals (Sweden)

    S. T. Kessel

    2013-01-01

    Full Text Available Aerial survey provides an important tool to assess the abundance of both terrestrial and marine vertebrates. To date, limited work has tested the effectiveness of this technique to estimate the abundance of smaller shark species. In Bimini, Bahamas, the lemon shark (Negaprion brevirostris shows high site fidelity to a shallow sandy lagoon, providing an ideal test species to determine the effectiveness of localised aerial survey techniques for a Carcharhinid species in shallow subtropical waters. Between September 2007 and September 2008, visual surveys were conducted from light aircraft following defined transects ranging in length between 8.8 and 4.4 km. Count results were corrected for “availability”, “perception”, and “survey intensity” to provide unbiased abundance estimates. The abundance of lemon sharks was greatest in the central area of the lagoon during high tide, with a change in abundance distribution to the east and western regions of the lagoon with low tide. Mean abundance of sharks was estimated at 49 (±8.6 individuals, and monthly abundance was significantly positively correlated with mean water temperature. The successful implementation of the aerial survey technique highlighted the potential of further employment for shark abundance assessments in shallow coastal marine environments.

  8. Physiological Optics of the Eye of the Juvenile Lemon Shark (Negaprion brevirostris).

    Science.gov (United States)

    1980-05-01

    fUr Lher affects of ametropia ) is the distance between the second nodal point vI lhe -’otoreceptor layer. This dimension is known as the posterior...gauge on the negative effect of ametropia on visual acuity, t the size of these retinal blur circles can be calculated using the schematic eye, 96...the working distance between retinoscopist and subject eye. My retinoscopic measurements of the underwater ametropia in juvenile lemon sharks have been

  9. Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868, in Los Roques Archipelago National Park, Venezuela

    Directory of Open Access Journals (Sweden)

    Rafael Tavares

    2016-01-01

    Full Text Available The protection of the habitats used by juvenile sharks is a management strategy that has recently caught the attention of fishery biologists. In the present study, we evaluated the population of the lemon shark (Negaprion brevirostris from Los Roques Archipelago in order to identify the nursery area, describe the size composition, and examine the variation in nocturnal activity of the juvenile individuals. The data analysed came from three different sources: commercial shark fishery, tag-recapture sampling, and visual records. A total of 375 lemon sharks with total lengths between 55 and 281 cm were recorded during the study period. Overall data showed that the area occupied by juvenile lemon sharks was clearly partitioned into primary and secondary nurseries. Additionally, nighttime activity seemed to change according to the size of sharks in the primary nursery, suggesting a reduction of time activity overlapping among juveniles of distinct size/age. Results suggest that the strategy of utilization of the primary nurseries by the lemon shark may lead to important ecological benefits by reducing the competition, predation and natural mortality.

  10. Genetic network and breeding patterns of a sicklefin lemon shark (Negaprion acutidens population in the Society Islands, French Polynesia.

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    Johann Mourier

    Full Text Available Human pressures have put many top predator populations at risk of extinction. Recent years have seen alarming declines in sharks worldwide, while their resilience remains poorly understood. Studying the ecology of small populations of marine predators is a priority to better understand their ability to withstand anthropogenic and environmental stressors. In the present study, we monitored a naturally small island population of 40 adult sicklefin lemon sharks in Moorea, French Polynesia over 5 years. We reconstructed the genetic relationships among individuals and determined the population's mating system. The genetic network illustrates that all individuals, except one, are interconnected at least through one first order genetic relationship. While this species developed a clear inbreeding avoidance strategy involving dispersal and migration, the small population size, low number of breeders, and the fragmented environment characterizing these tropical islands, limits its complete effectiveness.

  11. Two new species and a new phyllobothriid cestode genus from sharks of the genus Negaprion Whitley (Carcharhiniformes).

    Science.gov (United States)

    Ruhnke, T R; Workman, R E

    2013-05-01

    Alexandercestus n. g. (Cestoda: Tetraphyllidea) is erected for two cestode species found parasitising the two known species of lemon sharks (Carcharhiniformes: Negaprion spp.). This new genus differs from all other phyllobothriid genera except for Hemipristicola Cutmore, Theiss, Bennett & Cribb, 2011, Marsupiobothrium Yamaguti, 1952, Nandocestus Reyda, 2008, Orectolobicestus Ruhnke, Caira & Carpenter 2006, Orygmatobothrium Diesing, 1863, Paraorygmatobothrium Ruhnke, 1994 and Phyllobothrium van Beneden, 1849 in possessing uniloculate bothridia with an apical sucker and neck scutes. Alexandercestus differs from Orectolobicestus and Nandocestus in lacking marginal loculi on the bothridia, from Paraorygmatobothrium in possessing uninterrupted vitelline follicles at the level of the ovary and from Phyllobothrium in being euapolytic as opposed to anapolytic and in lacking posteriorly bifid bothridia. The new genus lacks the central accessory bothridial organ seen in specimens of Orygmatobothrium, and lacks the central bothridial accessory sucker of specimens of Marsupiobothrium. Alexandercestus spp. compare most favourably with specimens of Hemipristicola, especially with respect to aspects of proglottid morphology, but differ in possessing aristate gladiate spinitriches rather than serrate gladiate spinitriches on the proximal bothridial surface. In addition, the bothridia of Alexandercestus spp. are comparatively more fleshy and foliose than those in specimens of Hemipristicola. Two new species of Alexandercestus n. g. are described, Alexandercestus gibsoni n. sp. from Negaprion acutidens, collected from off northern Australia and the Marshall Islands, and Alexandercestus manteri n. sp. from N. brevirostris, collected off the islands of Bimini and the Florida Keys. The two new species differ in total length and vitelline follicle distribution. Bayesian inference and parsimony analysis of the D1-D3 region of the large nuclear ribosomal DNA of 17 published and seven

  12. Social learning in juvenile lemon sharks, Negaprion brevirostris

    NARCIS (Netherlands)

    Guttridge, Tristan L.; van Dijk, Sander; Stamhuis, Eize J.; Krause, Jens; Gruber, Samuel H.; Brown, Culum

    Social learning is taxonomically widespread and can provide distinct behavioural advantages, such as in finding food or avoiding predators more efficiently. Although extensively studied in bony fishes, no such empirical evidence exists for cartilaginous fishes. Our aim in this study was to

  13. Velocity Deficits in the Wake of Model Lemon Shark Dorsal Fins Measured with Particle Image Velocimetry

    Science.gov (United States)

    Terry, K. N.; Turner, V.; Hackett, E.

    2017-12-01

    Aquatic animals' morphology provides inspiration for human technological developments, as their bodies have evolved and become adapted for efficient swimming. Lemon sharks exhibit a uniquely large second dorsal fin that is nearly the same size as the first fin, the hydrodynamic role of which is unknown. This experimental study looks at the drag forces on a scale model of the Lemon shark's unique two-fin configuration in comparison to drag forces on a more typical one-fin configuration. The experiments were performed in a recirculating water flume, where the wakes behind the scale models are measured using particle image velocimetry. The experiments are performed at three different flow speeds for both fin configurations. The measured instantaneous 2D distributions of the streamwise and wall-normal velocity components are ensemble averaged to generate streamwise velocity vertical profiles. In addition, velocity deficit profiles are computed from the difference between these mean streamwise velocity profiles and the free stream velocity, which is computed based on measured flow rates during the experiments. Results show that the mean velocities behind the fin and near the fin tip are smallest and increase as the streamwise distance from the fin tip increases. The magnitude of velocity deficits increases with increasing flow speed for both fin configurations, but at all flow speeds, the two-fin configurations generate larger velocity deficits than the one-fin configurations. Because the velocity deficit is directly proportional to the drag force, these results suggest that the two-fin configuration produces more drag.

  14. Relative abundance and size of coastal sharks derived from commercial shark longline catch and effort data.

    Science.gov (United States)

    Carlson, J K; Hale, L F; Morgan, A; Burgess, G

    2012-04-01

    In the north-west Atlantic Ocean, stock assessments conducted for some commercially harvested coastal sharks indicate declines from 64 to 80% with respect to virgin population levels. While the status of commercially important species is available, abundance trend information for other coastal shark species in the north-west Atlantic Ocean are unavailable. Using a generalized linear modelling (GLM) approach, a relative abundance index was derived from 1994 to 2009 using observer data collected in a commercial bottom longline fishery. Trends in abundance and average size were estimated for bull shark Carcharhinus leucas, spinner shark Carcharhinus brevipinna, tiger shark Galeocerdo cuvier and lemon shark Negaprion brevirostris. Increases in relative abundance for all shark species ranged from 14% for C. brevipinna, 12% for C. leucas, 6% for N. brevirostris and 3% for G. cuvier. There was no significant change in the size at capture over the time period considered for all species. While the status of shark populations should not be based exclusively on abundance trend information, but ultimately on stock assessment models, results from this study provide some cause for optimism on the status of these coastal shark species. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  15. Mercury accumulation in sharks from the coastal waters of southwest Florida.

    Science.gov (United States)

    Rumbold, Darren; Wasno, Robert; Hammerschlag, Neil; Volety, Aswani

    2014-10-01

    As large long-lived predators, sharks are particularly vulnerable to exposure to methylmercury biomagnified through the marine food web. Accordingly, nonlethal means were used to collect tissues for determining mercury (Hg) concentrations and stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) from a total of 69 sharks, comprising 7 species, caught off Southwest Florida from May 2010 through June 2013. Species included blacknose (Carcharhinus acronotus), blacktip (C. limbatus), bull (C. leucas), great hammerhead (Sphyrna mokarran), lemon (Negaprion brevirostris), sharpnose (Rhizoprionodon terraenovae), and tiger sharks (Galeocerdo cuvier). The sharks contained Hg concentrations in their muscle tissues ranging from 0.19 mg/kg (wet-weight basis) in a tiger shark to 4.52 mg/kg in a blacktip shark. Individual differences in total length and δ(13)C explained much of the intraspecific variation in Hg concentrations in blacknose, blacktip, and sharpnose sharks, but similar patterns were not evident for Hg and δ(15)N. Interspecific differences in Hg concentration were evident with greater concentrations in slower-growing, mature blacktip sharks and lower concentrations in faster-growing, young tiger sharks than other species. These results are consistent with previous studies reporting age-dependent growth rate can be an important determinant of intraspecific and interspecific patterns in Hg accumulation. The Hg concentrations observed in these sharks, in particular the blacktip shark, also suggested that Hg may pose a threat to shark health and fitness.

  16. Long-term changes in species composition and relative abundances of sharks at a provisioning site.

    Science.gov (United States)

    Brunnschweiler, Juerg M; Abrantes, Kátya G; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier) displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas) of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive exclusion among shark

  17. Long-term changes in species composition and relative abundances of sharks at a provisioning site.

    Directory of Open Access Journals (Sweden)

    Juerg M Brunnschweiler

    Full Text Available Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-species shark feeding site in Fiji. Using direct observation sampling methods, eight species of sharks (bull shark Carcharhinus leucas, grey reef shark Carcharhinus amblyrhynchos, whitetip reef shark Triaenodon obesus, blacktip reef shark Carcharhinus melanopterus, tawny nurse shark Nebrius ferrugineus, silvertip shark Carcharhinus albimarginatus, sicklefin lemon shark Negaprion acutidens, and tiger shark Galeocerdo cuvier displayed inter-annual site fidelity between 2003 and 2012. Encounter rates and/or relative abundances of some species changed over time, overall resulting in more individuals (mostly C. leucas of fewer species being encountered on average on shark feeding dives at the end of the study period. Differences in shark community composition between the years 2004-2006 and 2007-2012 were evident, mostly because N. ferrugineus, C. albimarginatus and N. acutidens were much more abundant in 2004-2006 and very rare in the period of 2007-2012. Two explanations are offered for the observed changes in relative abundances over time, namely inter-specific interactions and operator-specific feeding protocols. Both, possibly in combination, are suggested to be important determinants of species composition and encounter rates, and relative abundances at this shark provisioning site in Fiji. This study, which includes the most species from a spatially confined shark provisioning site to date, suggests that long-term provisioning may result in competitive

  18. Novel acoustic technology for studying free-ranging shark social behaviour by recording individuals' interactions.

    Directory of Open Access Journals (Sweden)

    Tristan L Guttridge

    Full Text Available Group behaviours are widespread among fish but comparatively little is known about the interactions between free-ranging individuals and how these might change across different spatio-temporal scales. This is largely due to the difficulty of observing wild fish groups directly underwater over long enough time periods to quantify group structure and individual associations. Here we describe the use of a novel technology, an animal-borne acoustic proximity receiver that records close-spatial associations between free-ranging fish by detection of acoustic signals emitted from transmitters on other individuals. Validation trials, held within enclosures in the natural environment, on juvenile lemon sharks Negaprion brevirostris fitted with external receivers and transmitters, showed receivers logged interactions between individuals regularly when sharks were within 4 m ( approximately 4 body lengths of each other, but rarely when at 10 m distance. A field trial lasting 17 days with 5 juvenile lemon sharks implanted with proximity receivers showed one receiver successfully recorded association data, demonstrating this shark associated with 9 other juvenile lemon sharks on 128 occasions. This study describes the use of acoustic underwater proximity receivers to quantify interactions among wild sharks, setting the scene for new advances in understanding the social behaviours of marine animals.

  19. When bigger is not better: selection against large size, high condition and fast growth in juvenile lemon sharks.

    Science.gov (United States)

    Dibattista, J D; Feldheim, K A; Gruber, S H; Hendry, A P

    2007-01-01

    Selection acting on large marine vertebrates may be qualitatively different from that acting on terrestrial or freshwater organisms, but logistical constraints have thus far precluded selection estimates for the former. We overcame these constraints by exhaustively sampling and repeatedly recapturing individuals in six cohorts of juvenile lemon sharks (450 age-0 and 255 age-1 fish) at an enclosed nursery site (Bimini, Bahamas). Data on individual size, condition factor, growth rate and inter-annual survival were used to test the 'bigger is better', 'fatter is better' and 'faster is better' hypotheses of life-history theory. For age-0 sharks, selection on all measured traits was weak, and generally acted against large size and high condition. For age-1 sharks, selection was much stronger, and consistently acted against large size and fast growth. These results suggest that selective pressures at Bimini may be constraining the evolution of large size and fast growth, an observation that fits well with the observed small size and low growth rate of juveniles at this site. Our results support those of some other recent studies in suggesting that bigger/fatter/faster is not always better, and may often be worse.

  20. Species co-occurrence affects the trophic interactions of two juvenile reef shark species in tropical lagoon nurseries in Moorea (French Polynesia).

    Science.gov (United States)

    Matich, Philip; Kiszka, Jeremy J; Mourier, Johann; Planes, Serge; Heithaus, Michael R

    2017-06-01

    Food web structure is shaped by interactions within and across trophic levels. As such, understanding how the presence and absence of predators, prey, and competitors affect species foraging patterns is important for predicting the consequences of changes in species abundances, distributions, and behaviors. Here, we used plasma δ 13 C and δ 15 N values from juvenile blacktip reef sharks (Carcharhinus melanopterus) and juvenile sicklefin lemon sharks (Negaprion acutidens) to investigate how species co-occurrence affects their trophic interactions in littoral waters of Moorea, French Polynesia. Co-occurrence led to isotopic niche partitioning among sharks within nurseries, with significant increases in δ 15 N values among sicklefin lemon sharks, and significant decreases in δ 15 N among blacktip reef sharks. Niche segregation likely promotes coexistence of these two predators during early years of growth and development, but data do not suggest coexistence affects life history traits, such as body size, body condition, and ontogenetic niche shifts. Plasticity in trophic niches among juvenile blacktip reef sharks and sicklefin lemon sharks also suggests these predators are able to account for changes in community structure, resource availability, and intra-guild competition, and may fill similar functional roles in the absence of the other species, which is important as environmental change and human impacts persist in coral reef ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Was everything bigger in Texas? Characterization and trends of a land-based recreational shark fishery

    Science.gov (United States)

    Ajemian, Matthew J.; Jose, Philip D.; Froeschke, John T.; Wildhaber, Mark L.; Stunz, Gregory W.

    2016-01-01

    Although current assessments of shark population trends involve both fishery-independent and fishery-dependent data, the latter are generally limited to commercial landings that may neglect nearshore coastal habitats. Texas has supported the longest organized land-based recreational shark fishery in the United States, yet no studies have used this “non-traditional” data source to characterize the catch composition or trends in this multidecadal fishery. We analyzed catch records from two distinct periods straddling heavy commercial exploitation of sharks in the Gulf of Mexico (historical period = 1973–1986; modern period = 2008–2015) to highlight and make available the current status and historical trends in Texas’ land-based shark fishery. Catch records describing large coastal species (>1,800 mm stretched total length [STL]) were examined using multivariate techniques to assess catch seasonality and potential temporal shifts in species composition. These fishery-dependent data revealed consistent seasonality that was independent of the data set examined, although distinct shark assemblages were evident between the two periods. Similarity percentage analysis suggested decreased contributions of Lemon Shark Negaprion brevirostris over time and a general shift toward the dominance of Bull Shark Carcharhinus leucas and Blacktip Shark C. limbatus. Comparisons of mean STL for species captured in historical and modern periods further identified significant decreases for both Bull Sharks and Lemon Sharks. Size structure analysis showed a distinct paucity of landed individuals over 2,000 mm STL in recent years. Although inherent biases in reporting and potential gear-related inconsistencies undoubtedly influenced this fishery-dependent data set, the patterns in our findings documented potential declines in the size and occurrence of select large coastal shark species off Texas, consistent with declines reported in the Gulf of Mexico. Future management efforts

  2. Comparative Use of a Caribbean Mesophotic Coral Ecosystem and Association with Fish Spawning Aggregations by Three Species of Shark.

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    Alexandria E Pickard

    Full Text Available Understanding of species interactions within mesophotic coral ecosystems (MCEs; ~ 30-150 m lags well behind that for shallow coral reefs. MCEs are often sites of fish spawning aggregations (FSAs for a variety of species, including many groupers. Such reproductive fish aggregations represent temporal concentrations of potential prey that may be drivers of habitat use by predatory species, including sharks. We investigated movements of three species of sharks within a MCE and in relation to FSAs located on the shelf edge south of St. Thomas, United States Virgin Islands. Movements of 17 tiger (Galeocerdo cuvier, seven lemon (Negaprion brevirostris, and six Caribbean reef (Carcharhinus perezi sharks tagged with acoustic transmitters were monitored within the MCE using an array of acoustic receivers spanning an area of 1,060 km2 over a five year period. Receivers were concentrated around prominent grouper FSAs to monitor movements of sharks in relation to these temporally transient aggregations. Over 130,000 detections of telemetered sharks were recorded, with four sharks tracked in excess of 3 years. All three shark species were present within the MCE over long periods of time and detected frequently at FSAs, but patterns of MCE use and orientation towards FSAs varied both spatially and temporally among species. Lemon sharks moved over a large expanse of the MCE, but concentrated their activities around FSAs during grouper spawning and were present within the MCE significantly more during grouper spawning season. Caribbean reef sharks were present within a restricted portion of the MCE for prolonged periods of time, but were also absent for long periods. Tiger sharks were detected throughout the extent of the acoustic array, with the MCE representing only portion of their habitat use, although a high degree of individual variation was observed. Our findings indicate that although patterns of use varied, all three species of sharks repeatedly

  3. Comparative Use of a Caribbean Mesophotic Coral Ecosystem and Association with Fish Spawning Aggregations by Three Species of Shark.

    Science.gov (United States)

    Pickard, Alexandria E; Vaudo, Jeremy J; Wetherbee, Bradley M; Nemeth, Richard S; Blondeau, Jeremiah B; Kadison, Elizabeth A; Shivji, Mahmood S

    2016-01-01

    Understanding of species interactions within mesophotic coral ecosystems (MCEs; ~ 30-150 m) lags well behind that for shallow coral reefs. MCEs are often sites of fish spawning aggregations (FSAs) for a variety of species, including many groupers. Such reproductive fish aggregations represent temporal concentrations of potential prey that may be drivers of habitat use by predatory species, including sharks. We investigated movements of three species of sharks within a MCE and in relation to FSAs located on the shelf edge south of St. Thomas, United States Virgin Islands. Movements of 17 tiger (Galeocerdo cuvier), seven lemon (Negaprion brevirostris), and six Caribbean reef (Carcharhinus perezi) sharks tagged with acoustic transmitters were monitored within the MCE using an array of acoustic receivers spanning an area of 1,060 km2 over a five year period. Receivers were concentrated around prominent grouper FSAs to monitor movements of sharks in relation to these temporally transient aggregations. Over 130,000 detections of telemetered sharks were recorded, with four sharks tracked in excess of 3 years. All three shark species were present within the MCE over long periods of time and detected frequently at FSAs, but patterns of MCE use and orientation towards FSAs varied both spatially and temporally among species. Lemon sharks moved over a large expanse of the MCE, but concentrated their activities around FSAs during grouper spawning and were present within the MCE significantly more during grouper spawning season. Caribbean reef sharks were present within a restricted portion of the MCE for prolonged periods of time, but were also absent for long periods. Tiger sharks were detected throughout the extent of the acoustic array, with the MCE representing only portion of their habitat use, although a high degree of individual variation was observed. Our findings indicate that although patterns of use varied, all three species of sharks repeatedly utilized the MCE and

  4. Two decades of genetic profiling yields first evidence of natal philopatry and long-term fidelity to parturition sites in sharks

    KAUST Repository

    Feldheim, Kevin Andrew

    2013-12-09

    Sharks are a globally threatened group of marine fishes that often breed in their natal region of origin. There has even been speculation that female sharks return to their exact birthplace to breed (\\'natal philopatry\\'), which would have important conservation implications. Genetic profiling of lemon sharks (Negaprion brevirostris) from 20 consecutive cohorts (1993-2012) at Bimini, Bahamas, showed that certain females faithfully gave birth at this site for nearly two decades. At least six females born in the 1993-1997 cohorts returned to give birth 14-17 years later, providing the first direct evidence of natal philopatry in the chondrichthyans. Long-term fidelity to specific nursery sites coupled with natal philopatry highlights the merits of emerging spatial and local conservation efforts for these threatened predators. © 2013 John Wiley & Sons Ltd.

  5. Correlations of metabolic rate and body acceleration in three species of coastal sharks under contrasting temperature regimes.

    Science.gov (United States)

    Lear, Karissa O; Whitney, Nicholas M; Brewster, Lauran R; Morris, Jack J; Hueter, Robert E; Gleiss, Adrian C

    2017-02-01

    The ability to produce estimates of the metabolic rate of free-ranging animals is fundamental to the study of their ecology. However, measuring the energy expenditure of animals in the field has proved difficult, especially for aquatic taxa. Accelerometry presents a means of translating metabolic rates measured in the laboratory to individuals studied in the field, pending appropriate laboratory calibrations. Such calibrations have only been performed on a few fish species to date, and only one where the effects of temperature were accounted for. Here, we present calibrations between activity, measured as overall dynamic body acceleration (ODBA), and metabolic rate, measured through respirometry, for nurse sharks (Ginglymostoma cirratum), lemon sharks (Negaprion brevirostris) and blacktip sharks (Carcharhinus limbatus). Calibrations were made at a range of volitional swimming speeds and experimental temperatures. Linear mixed models were used to determine a predictive equation for metabolic rate based on measured ODBA values, with the optimal model using ODBA in combination with activity state and temperature to predict metabolic rate in lemon and nurse sharks, and ODBA and temperature to predict metabolic rate in blacktip sharks. This study lays the groundwork for calculating the metabolic rate of these species in the wild using acceleration data. © 2017. Published by The Company of Biologists Ltd.

  6. Effect of weight and frontal area of external telemetry packages on the kinematics, activity levels and swimming performance of small-bodied sharks.

    Science.gov (United States)

    Bouyoucos, I A; Suski, C D; Mandelman, J W; Brooks, E J

    2017-05-01

    This study sought to observe the effects of submerged weight and frontal cross-sectional area of external telemetry packages on the kinematics, activity levels and swimming performance of small-bodied juvenile sharks, using lemon sharks Negaprion brevirostris (60-80 cm total length, L T ) as a model species. Juveniles were observed free-swimming in a mesocosm untagged and with small and large external accelerometer packages that increased frontal cross-sectional area of the animals and their submerged weight. Despite adhering to widely used standards for tag mass, the presence of an external telemetry package altered swimming kinematics, activity levels and swimming performance of juvenile N. brevirostris relative to untagged individuals, suggesting that tag mass is not a suitable standalone metric of device suitability. Changes in swimming performance could not be detected from tail-beat frequency, which suggests that tail-beat frequency is an unsuitable standalone metric of swimming performance for small N. brevirostris. Lastly, sharks experienced treatment-specific changes in activity level and swimming kinematics from morning to afternoon observation. Therefore, the presence of external telemetry packages altered the kinematics, activity levels and swimming performance of small young-of-the-year N. brevirostris and these data may therefore be relevant to other similar-sized juveniles of other shark species. © 2017 The Fisheries Society of the British Isles.

  7. Shark Cartilage

    Science.gov (United States)

    Shark cartilage (tough elastic tissue that provides support, much as bone does) used for medicine comes primarily from sharks ... Several types of extracts are made from shark cartilage including squalamine lactate, AE-941, and U-995. ...

  8. Sharks senses and shark repellents.

    Science.gov (United States)

    Hart, Nathan S; Collin, Shaun P

    2015-01-01

    Despite over 70 years of research on shark repellents, few practical and reliable solutions to prevent shark attacks on humans or reduce shark bycatch and depredation in commercial fisheries have been developed. In large part, this deficiency stems from a lack of fundamental knowledge of the sensory cues that drive predatory behavior in sharks. However, the widespread use of shark repellents is also hampered by the physical constraints and technical or logistical difficulties of deploying substances or devices in an open-water marine environment to prevent an unpredictable interaction with a complex animal. Here, we summarize the key attributes of the various sensory systems of sharks and highlight residual knowledge gaps that are relevant to the development of effective shark repellents. We also review the most recent advances in shark repellent technology within the broader historical context of research on shark repellents and shark sensory systems. We conclude with suggestions for future research that may enhance the efficacy of shark repellent devices, in particular, the continued need for basic research on shark sensory biology and the use of a multi-sensory approach when developing or deploying shark repellent technology. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  9. Shark Detectives

    Science.gov (United States)

    Hitt, Dia

    2005-01-01

    Oceans are often considered mysterious, fascinating places filled with unique and scary animals. One of the most misunderstood and therefore scariest animals is the shark, yet the whale shark, the world's largest fish, is considered harmless to humans. This student-directed activity involves research, deductive reasoning, and students' own…

  10. 21 CFR 146.114 - Lemon juice.

    Science.gov (United States)

    2010-04-01

    ... food. The lemon oil and lemon essence (derived from lemons) content may be adjusted in accordance with... juice, as defined in this paragraph, may be preserved by heat sterilization (canning), refrigeration...

  11. Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon

    International Nuclear Information System (INIS)

    Matulik, Adam G.; Kerstetter, David W.; Hammerschlag, Neil; Divoll, Timothy; Hammerschmidt, Chad R.; Evers, David C.

    2017-01-01

    Mercury bioaccumulation is frequently observed in marine ecosystems, often with stronger effects at higher trophic levels. We compared total mercury (THg) and methylmercury (MeHg) from muscle with length, comparative isotopic niche, and diet (via δ 13 C and δ 15 N) among four sympatric coastal sharks in Florida Bay (USA): blacknose, blacktip, bull, and lemon. Mercury in blacknose and blacktip sharks increased significantly with size, whereas bull and lemon sharks had a high variance in mercury relative to size. Both δ 13 C and δ 15 N were consistent with general resource use and trophic position relationships across all species. A significant relationship was observed between δ 13 C and mercury in blacktip sharks, suggesting an ontogenetic shift isotopic niche, possibly a dietary change. Multiple regression showed that δ 13 C and δ 15 N were the strongest factors regarding mercury bioaccumulation in individuals across all species. Additional research is recommended to resolve the mechanisms that determine mercury biomagnification in individual shark species. - Highlights: • Total mercury (THg) and methylmercury (MeHg) examined in sympatric coastal sharks: lemon, bull, blacknose, blacktip • THg concentrations increased with size of blacknose and blacktip sharks • THg concentrations in bull and lemon sharks were unrelated to length • THg and δ 13 C were related in blacktip sharks; no other direct relationships between Hg and δ 13 C or δ 15 N and were observed • Multiple regression found δ 13 C and δ 15 N have stronger relationships to Hg than length for the species and lengths assessed

  12. 50 CFR Appendix A to Part 635 - Species Tables

    Science.gov (United States)

    2010-10-01

    ... Lemon, Negaprion brevirostris Nurse, Ginglymostoma cirratum Scalloped hammerhead, Sphyrna lewini Smooth..., Lutjanus analis Nurse shark, Ginglymostoma cirratum Queen snapper, Etelis oculatus Red grouper, Epinephelus... and will not become effective until approval has been given by the Office of Management and Budget. ...

  13. Effect of lemon juice on blood pressure

    OpenAIRE

    SARI, Aysel; SELİM, Nevzat; DİLEK, Melda; AYDOĞDU, Turkan; ADIBELLİ, Zelal; BÜYÜKKAYA, Piltan; AKPOLAT, Tekin

    2012-01-01

    Lemon juice has commonly been used by hypertensive patients in order to lower blood pressure (BP) acutely when BP is raised or as an alternative/complementary therapy for expectation of chronic improvement. Grapefruit, a citrus fruit like lemon, causes clinically significant interactions with a variety of drugs including calcium antagonists. The aims of this study were to investigate acute and chronic effects of lemon juice on BP among hypertensive patients. Ninty-eight patients were included...

  14. Instant BrainShark

    CERN Document Server

    Li, Daniel

    2013-01-01

    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. ""Instant BrainShark"" is a step-by-step guide to creating online presentations using BrainShark. The book covers digital marketing best practices alongside tips for sales conversions. The book is written in an easy-to-read style for anybody to easily pick up and get started with BrainShark.Instant BrainShark is for anyone who wants to use BrainShark to create presentations online and share them around the community. The book is also useful for developers who are looking to explore

  15. 7 CFR 29.1031 - Lemon (L).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Lemon (L). 29.1031 Section 29.1031 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 92) § 29.1031 Lemon (L). Yellow. [42 FR 21092, Apr. 25, 1977. Redesignated at 49 FR 16755, Apr. 20...

  16. The Greenland shark

    DEFF Research Database (Denmark)

    Costantini, David; Smith, Shona; Killen, Shaun S.

    2017-01-01

    the oxidative status of the Greenland shark (Somniosus microcephalus), which has recently been found as the longest living vertebrate animal known to science with a lifespan of at least 272years. As compared to other species, the Greenland shark had body mass-corrected values of muscle glutathione peroxidase...... that the values of metrics of oxidative status we measured might be linked to ecological features (e.g., adaptation to cold waters and deep dives) of this shark species rather to its lifespan....

  17. Ergodicity of the generalized lemon billiards

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingyu [Department of Computer Science, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801-2302 (United States); Mohr, Luke; Zhang, Hong-Kun, E-mail: hongkun@math.umass.edu; Zhang, Pengfei [Department of Mathematics and Statistics, UMass Amherst, Amherst, Massachusetts 01003 (United States)

    2013-12-15

    In this paper, we study a two-parameter family of convex billiard tables, by taking the intersection of two round disks (with different radii) in the plane. These tables give a generalization of the one-parameter family of lemon-shaped billiards. Initially, there is only one ergodic table among all lemon tables. In our generalized family, we observe numerically the prevalence of ergodicity among the some perturbations of that table. Moreover, numerical estimates of the mixing rate of the billiard dynamics on some ergodic tables are also provided.

  18. Sharks of the order Carcharhiniformes

    National Research Council Canada - National Science Library

    Compagno, L.J.V

    1988-01-01

    This book is a general review, taxonomic revision, and phylogenetic analysis of the carcharhinoids, the largest group of living sharks, which comprises almost 60 percent or 200 of known shark species...

  19. Shark complement: an assessment.

    Science.gov (United States)

    Smith, S L

    1998-12-01

    The classical (CCP) and alternative (ACP) pathways of complement activation have been established for the nurse shark (Ginglymostoma cirratum). The isolation of a cDNA clone encoding a mannan-binding protein-associated serine protease (MASP)-1-like protein from the Japanese dogfish (Triakis scyllia) suggests the presence of a lectin pathway. The CCP consists of six functionally distinct components: C1n, C2n, C3n, C4n, C8n and C9n, and is activated by immune complexes in the presence of Ca++ and Mg++ ions. The ACP is antibody independent, requiring Mg++ ions and a heat-labile 90 kDa factor B-like protein for activity. Proteins considered homologues of C1q, C3 and C4 (C2n) of the mammalian complement system have been isolated from nurse shark serum. Shark C1q is composed of at least two chain types each showing 50% identity to human C1q chains A and B. Partial sequence of the globular domain of one of the chains shows it to be C1q-like rather than like mannan-binding protein. N-terminal amino acid sequences of the alpha and beta chain of shark C3 and C4 molecules show significant identity with corresponding human C3 and C4 chains. A sequence representing shark C4 gamma chain, shows little similarity to human C4 gamma chain. The terminal shark components C8n and C9n are functional analogues of mammalian C8 and C9. Anaphylatoxin activity has been demonstrated in activated shark serum, and porcine C5a desArg induces shark leucocyte chemotaxis. The deduced amino acid sequence of a partial C3 cDNA clone from the nurse shark shows 50%, 30% and 24% homology with the corresponding region of mammalian C3, C4 and alpha 2-macroglobulin. Deduced amino acid sequence data from partial Bf/C2 cDNA clones, two from the nurse shark and one from the Japanese dogfish, suggest that at least one species of elasmobranch has two distinct Bf/C2 genes.

  20. Concentration of lemon pectin extract by ultrafiltration

    Directory of Open Access Journals (Sweden)

    Damián Stechina

    2012-09-01

    Full Text Available Current annual lemon production in Argentina is about 900 thousand t. 75% is used industrially to obtain pasteurized juice concentrate. Since 40 - 45 % of citrus fruit content is peel and seeds, the annual lemon residue yield is 360 thousand t. Lemon peel contains about 30% (B.S. of peptic substances with an important commercial value due to its gelling and thickening properties for food, chemical, pharmacological and cosmetic products. Membrane processes have many applications in food manufacture. The objective of this study is to analyze the influence of ultrafiltration operating variables on instant permeate flow (Fp and on the energy requirement for pectin extract concentration from lemon peel. A DDS lab module was used, lab 20-772 model with synthetic material membranes, 9 kDa, shear force, the intrinsic membrane resistance (Rm being 3*1013 m -1 . Results show that Fp decrease caused by polarization induced resistance occurrence and the influence of operating variables on Fp offer relevant data to estimate the energy requirement in relation to feeding flow at constant temperature, which may be compared to pectin concentration increase in the retained flow in relation to initial extract concentration.

  1. Implantable Neural Interfaces for Sharks

    Science.gov (United States)

    2007-05-01

    technology for recording and stimulating from the auditory and olfactory sensory nervous systems of the awake, swimming nurse shark , G. cirratum (Figures...overlay of the central nervous system of the nurse shark on a horizontal MR image. Implantable Neural Interfaces for Sharks ...Neural Interfaces for Characterizing Population Responses to Odorants and Electrical Stimuli in the Nurse Shark , Ginglymostoma cirratum.” AChemS Abs

  2. The shark's fin

    International Nuclear Information System (INIS)

    Listinsky, J.L.; Griffiths, H.J.

    1989-01-01

    Initial plain film studies of seven patients with facet fracture-dislocations of the cervical spine were examined retrospectively. Rotation of the cross-table lateral film from a standard vetical viewing orientation to a simulated brow-down position allowed easier appreciation of the dislocated pillar in six of the seven patients. The displaced pillar had an appearance similar to that of the dorsal fin of a shark. We conclude that the finding of a shark's fin appearance of an articular pillar in a traumatized patient warrants further radiographic studies. (author). 8 refs.; 3 figs

  3. Some properties of kefir enriched with apple and lemon fiber

    Directory of Open Access Journals (Sweden)

    Busra Goncu

    2017-01-01

    Full Text Available The effects of apple and lemon fiber addition on some properties of kefir were investigated. Five different kefirs were produced (A is control, B, C, D, E, F and G: contain 0.25 % apple fiber, 0.5 % apple fiber, 1 % apple fiber, 0.25 % lemon fiber, 0.5 % lemon fiber and 1 % lemon fiber, respectively and stored for 20 days at 4±1 °C. pH, titratable acidity, dry matter, water activity, water holding capacity, viscosity, L, a and b values, sensorial analysis, total lactic bacteria, Lactococcus spp., Leuconostoc spp. and yeast counts of kefirs were determined at 1st, 10th and 20th days of storage. The addition of apple and lemon fiber enhanced rheological, microbiological and sensorial properties of kefirs (p<0.01. Apple and lemon fiber could be used for kefir production at a rate of 0.25 or 0.5 %.

  4. Antimicrobial and antioxidant activity of lemon balm Kombucha

    OpenAIRE

    Velićanski Aleksandra S.; Cvetković Dragoljub D.; Markov Siniša L.; Tumbas Vesna T.; Savatović Slađana M.

    2007-01-01

    Kombucha is a beverage traditionally produced by metabolic activity of yeasts and acetic acid bacteria. The antimicrobial activity of lemon balm kombucha as well as of particular control samples was determined by agar-well diffusion method. Antioxidant activity on stable 1,1-diphenyl-2-picrylhydrazyl radicals of lemon balm kombucha and lemon balm tea was determined by electron spin resonance spectroscopy. Acetic acid, Kombucha samples and heat-denaturated kombucha showed significant antimicro...

  5. Some properties of kefir enriched with apple and lemon fiber

    OpenAIRE

    Busra Goncu; Asli Celikel; Mutlu B. Guler-Akin; M. Serdar Akin

    2017-01-01

    The effects of apple and lemon fiber addition on some properties of kefir were investigated. Five different kefirs were produced (A is control, B, C, D, E, F and G: contain 0.25 % apple fiber, 0.5 % apple fiber, 1 % apple fiber, 0.25 % lemon fiber, 0.5 % lemon fiber and 1 % lemon fiber, respectively) and stored for 20 days at 4±1 °C. pH, titratable acidity, dry matter, water activity, water holding capacity, viscosity, L, a and b values, sensorial analysis, total lactic bacteria, Lactococcus ...

  6. Chemotaxis of nurse shark leukocytes.

    Science.gov (United States)

    Obenauf, S D; Smith, S H

    1985-01-01

    Studies were conducted to determine the ability of leukocytes from the nurse shark to migrate in an in vitro micropore filter chemotaxis assay and to determine optimal assay conditions and suitable attractants for such an assay. A migratory response was seen with several attractants: activated rat serum, activated shark plasma, and a pool of shark complement components. Only the response to activated rat serum was chemotactic, as determined by the checkerboard assay.

  7. 50 CFR 600.1204 - Shark finning; possession at sea and landing of shark fins.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Shark finning; possession at sea and landing of shark fins. 600.1204 Section 600.1204 Wildlife and Fisheries FISHERY CONSERVATION AND... PROVISIONS Shark Finning § 600.1204 Shark finning; possession at sea and landing of shark fins. (a)(1) No...

  8. Juan's Dilemma: A New Twist on the Old Lemon Battery

    Science.gov (United States)

    Hunt, Vanessa; Sorey, Timothy; Balandova, Evguenia; Palmquist, Bruce

    2010-01-01

    When life hands you lemons, make a battery! In this article, the authors describe an activity they refer to as "Juan's Dilemma," an extension of the familiar lemon-battery activity (Goodisman 2001). Juan's Dilemma integrates oxidation and reduction chemistry with circuit theory in a fun, real-world exercise. The authors designed this activity for…

  9. 78 FR 46610 - Lemon Juice From Argentina and Mexico

    Science.gov (United States)

    2013-08-01

    ... Argentina and Mexico Determination On the basis of the record \\1\\ developed in the subject five-year reviews... determines that termination of the suspended antidumping duty investigation on lemon juice from Mexico would...), entitled Lemon Juice from Argentina and Mexico: Investigation Nos. 731-TA-1105-1106 (Review). By order of...

  10. 78 FR 47006 - Lemon Juice From Argentina and Mexico

    Science.gov (United States)

    2013-08-02

    ... Argentina and Mexico Determination On the basis of the record \\1\\ developed in the subject five-year reviews... determines that termination of the suspended antidumping duty investigation on lemon juice from Mexico would...), entitled Lemon Juice from Argentina and Mexico: Investigation Nos. 731-TA-1105-1106 (Review). By order of...

  11. Bioaccumulation of organohalogenated compounds in sharks and rays from the southeastern USA.

    Science.gov (United States)

    Weijs, Liesbeth; Briels, Nathalie; Adams, Douglas H; Lepoint, Gilles; Das, Krishna; Blust, Ronny; Covaci, Adrian

    2015-02-01

    Organohalogenated compounds are widespread in the marine environment and can be a serious threat to organisms in all levels of aquatic food webs, including elasmobranch species. Information about the concentrations of POPs (persistent organic pollutants) and of MeO-PBDEs (methoxylated polybrominated diphenyl ethers) in elasmobranchs is scarce and potential toxic effects are poorly understood. The aims of the present study were therefore to investigate the occurrence of multiple POP classes (PCBs, PBDEs, DDXs, HCB, CHLs) and of MeO-PBDEs in various elasmobranch species from different trophic levels in estuarine and marine waters of the southeastern United States. Overall, levels and patterns of PCBs, PBDEs, DDXs, HCB, CHLs and of MeO-PBDEs varied according to the species, maturity stage, gender and habitat type. The lowest levels of POPs were found in Atlantic stingrays and the highest levels were found in bull sharks. As both species are respectively near the bottom and at top of the trophic web, with juvenile bull sharks frequently feeding on Atlantic stingrays, these findings further suggest a bioaccumulation and biomagnification process with trophic position. MeO-PBDEs were not detected in Atlantic stingrays, but were found in all shark species. HCB was not found in Atlantic stingrays, bonnetheads or lemon sharks, but was detected in the majority of bull sharks examined. Comparison with previous studies suggests that Atlantic stingrays may be experiencing toxic effects of PCBs and DDXs on their immune system. However, the effect of these compounds on the health of shark species remains unclear. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Necrophagy of a nurse shark (Ginglymostoma cirratum) by tiger sharks (Galeocerdo cuvier)

    OpenAIRE

    Rada, Danilo P; Programa de Pós Graduação em Ciências Biológicas, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil; Burgess, George H; Florida Museum of Natural History University of Florida, Gainesville, Florida, U.S.A.; Rosa, Ricardo S; Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.; Gadig, Otto F; Laboratório de Pesquisa em Elasmobrânquios e Nécton Marinho, UNESP, São Vicente, São Paulo, Brazil.

    2015-01-01

    The aim of this study is to report a scavenging event, involving the consumption of a nurse shark, Ginglymostoma cirratum, by tiger sharks, Galeocerdo cuvier, at Fernando de Noronha archipelago, Brazil. Recreational divers found and photographed a bitten nurse shark carcass, just after sighting two tiger sharks near of the site. We estimated the sharks total lengths and discussed aspects of this feeding interaction using of images of forensic analysis. A straight cut on the nurse shark caudal...

  13. Highly migratory shark fisheries research by the National Shark Research Consortium (NSRC), 2002-2007

    OpenAIRE

    Hueter, Robert E.; Cailliet, Gregor M.; Ebert, David A.; Musick, John A.; Burgess, George H.

    2007-01-01

    The National Shark Research Consortium (NSRC) includes the Center for Shark Research at Mote Marine Laboratory, the Pacific Shark Research Center at Moss Landing Marine Laboratories, the Shark Research Program at the Virginia Institute of Marine Science, and the Florida Program for Shark Research at the University of Florida. The consortium objectives include shark-related research in the Gulf of Mexico and along the Atlantic and Pacific coasts of the U.S., education and scientific cooperation.

  14. Antimicrobial and antioxidant activity of lemon balm Kombucha

    Directory of Open Access Journals (Sweden)

    Velićanski Aleksandra S.

    2007-01-01

    Full Text Available Kombucha is a beverage traditionally produced by metabolic activity of yeasts and acetic acid bacteria. The antimicrobial activity of lemon balm kombucha as well as of particular control samples was determined by agar-well diffusion method. Antioxidant activity on stable 1,1-diphenyl-2-picrylhydrazyl radicals of lemon balm kombucha and lemon balm tea was determined by electron spin resonance spectroscopy. Acetic acid, Kombucha samples and heat-denaturated kombucha showed significant antimicrobial activity against bacteria. However, there was no activity against yeasts and moulds. Kombucha showed higher antioxidant activity than tea sample for all applied sample volumes.

  15. Heavy metals binding properties of esterified lemon

    Energy Technology Data Exchange (ETDEWEB)

    Arslanoglu, Hasan; Altundogan, Hamdi Soner [Department of Chemical Engineering, Firat University, 23279 Elazig (Turkey); Tumen, Fikret, E-mail: ftumen@firat.edu.tr [Department of Chemical Engineering, Firat University, 23279 Elazig (Turkey)

    2009-05-30

    Sorption of Cd{sup 2+}, Cr{sup 3+}, Cu{sup 2+}, Ni{sup 2+}, Pb{sup 2+} and Zn{sup 2+} onto a carboxyl groups-rich material prepared from lemon was investigated in batch systems. The results revealed that the sorption is highly pH dependent. Sorption kinetic data indicated that the equilibrium was achieved in the range of 30-240 min for different metal ions and sorption kinetics followed the pseudo-second-order model for all metals studied. Relative sorption rate of various metal cations was found to be in the general order of Ni{sup 2+} > Cd{sup 2+} > Cu{sup 2+} > Pb{sup 2+} > Zn{sup 2+} > Cr{sup 3+}. The binding characteristics of the sorbent for heavy metal ions were analyzed under various conditions and isotherm data was accurately fitted to the Langmuir equation. The metal binding capacity order calculated from Langmuir isotherm was Pb{sup 2+} > Cu{sup 2+} > Ni{sup 2+} > Cd{sup 2+} > Zn{sup 2+} > Cr{sup 3+}. The mean free energy of metal sorption process calculated from Dubinin-Radushkevich parameter and the Polanyi potential was found to be in the range of 8-11 kJ mol{sup -1} for the metals studied showing that the main mechanism governing the sorption process seems to be ion exchange. The basic thermodynamic parameters of metals ion sorption process were calculated by using the Langmuir constants obtained from equilibration study. The {Delta}G{sup o} and {Delta}H{sup o} values for metals ion sorption on the lemon sorbent showed the process to be spontaneous and exothermic in nature. Relatively low {Delta}H{sup o} values revealed that physical adsorption significantly contributed to the mechanism.

  16. The Lemon Screamer, the Lasagna Cell, and the Physics Teacher.

    Science.gov (United States)

    Willis, Courtney W.; Nicholson, Lois

    1990-01-01

    Described is a demonstration which uses two electrodes attached to a piezoelectric buzzer that operates when inserted into a lemon. The calculation of cell potentials and the effects demonstrated are discussed. (CW)

  17. The Use of Alginate in Lemon Extract Effervescent Powder Production

    Directory of Open Access Journals (Sweden)

    Murdinah

    2015-11-01

    Full Text Available Study on the use of alginate in lemon (Citrus medica var lemon extract effervescent powder production has conducted. The aims of the research are to determine the optimum concentration of alginate used in lemon extract effervescent powder to produced best product and acceptance consumen.The lemon extract effervescent powder formula consisted of lemon extract powder, sucrose, aspartame, salt and effervescent mix (citric acid-tartrat acid-sodium bicarbonat. The alginate used in this study was extracted from Sargassum filipendula sea weed. The concentration of alginate used in lemon effervescent powder production was varied from 1; 2; 3 and 4%. The parameters observed to see the quality of the product were moisture content, ash content, pH, viscosity and organoleptic value (flavor, taste, viscosity, effec effervescent, effect sparkle and acceptance. Analysis of dietary fiber, sugar content, vitamin C content, total titratable acids, TPC and E.Coli to the best product. The result showed that the higher the concentration of alginate used in lemon effervescent powder production, the higher viscousness and the lower the organoleptic value. The optimum concentration of alginate used in the lemon extract effervescent powder processing was 1%. The characteristic this product 7.60% moisture content, 0.86% insoluble dietary fiber , 7.92% soluble dietary fiber, 3.74% sugar content, 55,26 mg/100 g vitamin C, 134.15 mL 0.1 NaOH/100 mL total titratable acids, 20 cPs viscosity, <2.5x102 coloni/mL TPC and E.Coli negative.

  18. Semi-automatic Citation Correction with Lemon8-XML

    Directory of Open Access Journals (Sweden)

    MJ Suhonos

    2009-03-01

    Full Text Available The Lemon8-XML software application, developed by the Public Knowledge Project (PKP, provides an open-source, computer-assisted interface for reliable citation structuring and validation. Lemon8-XML combines citation parsing algorithms with freely-available online indexes such as PubMed, WorldCat, and OAIster. Fully-automated markup of entire bibliographies may be a genuine possibility using this approach. Automated markup of citations would increase bibliographic accuracy while reducing copyediting demands.

  19. Extraction, characterisation, and enzymatic degradation of lemon peel pectins.

    NARCIS (Netherlands)

    Ros, J.M.; Schols, H.A.; Voragen, A.G.J.

    1996-01-01

    The albedo of Spanish lemons (16.0% w/w of lemon fresh weight) was extracted to obtain a chelating agent soluble pectin fraction, a diluted sodium hydroxide soluble pectin fraction and a residue (4.2, 1.8, and 5.0% w/w of fresh albedo, respectively). These fractions represented 61.3, 12.4, and 10.4%

  20. On two abnormal sharks from Gujarat

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalan, U.K.

    The description of the two abnormal sharks, Carchariaswalbeehmi and Eulamia dussumieri collected from Gujarat, India, is given Of these C walbeehmi was double-headed The other shark E dussumieri had thumb snouted albino...

  1. Shark Conservation: An Educational Approach Based on Children’s Knowledge and Perceptions toward Sharks

    Science.gov (United States)

    Chan, Sau Ying; Lee, Yeung Chung; Ip, Brian Ho Yeung; Cheang, Chi Chiu

    2016-01-01

    Shark conservation has become a focus of current international conservation efforts. However, the misunderstanding of sharks and their negative public portrayal may hinder their conservation. More importantly, the consumption of shark fin, which is very common in Chinese cultures, poses a significant threat to sharks. Hong Kong has long been the world’s largest shark fin trading center. Shark conservation would become more sustainable if public understanding of this predatory fish and an appreciation of its ecological significance could be promoted. It is possible that the demand for fins could be effectively managed through long-term educational efforts targeted at younger generations. To provide essential baseline data for planning of these educational efforts, this project investigated the perceptions of 11 to 12 year-old primary school students in Hong Kong about sharks, and their understanding of ecological concepts and shark-related knowledge. The findings indicate that these students lack sufficient knowledge and possess misconceptions about sharks and their ecological significance in the marine ecosystem. The students’ conceptual understanding level is strongly correlated with their perceptions. Correlational analyses further demonstrated a positive association between formal education and perceptions toward shark conservation. The students who favoured shark fin consumption did so because of its tastiness, whereas concerns about shark population decline and the cruelty of shark hunting were the main reasons for not favoring shark fin consumption. This pilot study provides preliminary but important insights into primary school education regarding the conservation of sharks. PMID:27684706

  2. Shark Conservation: An Educational Approach Based on Children's Knowledge and Perceptions toward Sharks.

    Science.gov (United States)

    Tsoi, Kwok Ho; Chan, Sau Ying; Lee, Yeung Chung; Ip, Brian Ho Yeung; Cheang, Chi Chiu

    Shark conservation has become a focus of current international conservation efforts. However, the misunderstanding of sharks and their negative public portrayal may hinder their conservation. More importantly, the consumption of shark fin, which is very common in Chinese cultures, poses a significant threat to sharks. Hong Kong has long been the world's largest shark fin trading center. Shark conservation would become more sustainable if public understanding of this predatory fish and an appreciation of its ecological significance could be promoted. It is possible that the demand for fins could be effectively managed through long-term educational efforts targeted at younger generations. To provide essential baseline data for planning of these educational efforts, this project investigated the perceptions of 11 to 12 year-old primary school students in Hong Kong about sharks, and their understanding of ecological concepts and shark-related knowledge. The findings indicate that these students lack sufficient knowledge and possess misconceptions about sharks and their ecological significance in the marine ecosystem. The students' conceptual understanding level is strongly correlated with their perceptions. Correlational analyses further demonstrated a positive association between formal education and perceptions toward shark conservation. The students who favoured shark fin consumption did so because of its tastiness, whereas concerns about shark population decline and the cruelty of shark hunting were the main reasons for not favoring shark fin consumption. This pilot study provides preliminary but important insights into primary school education regarding the conservation of sharks.

  3. Characteristics of the shark fisheries of Fiji

    Science.gov (United States)

    Glaus, Kerstin B. J.; Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia; White, William T.; Brunnschweiler, Juerg M.

    2015-12-01

    Limited information is available on artisanal and subsistence shark fisheries across the Pacific. The aim of this study was to investigate Fiji’s inshore fisheries which catch sharks. In January and February 2013, 253 semi-directive interviews were conducted in 117 villages and at local harbours on Viti Levu, Vanua Levu, Taveuni, Ovalau and a number of islands of the Mamanuca and Yasawa archipelagos. Of the 253 interviewees, 81.4% reported to presently catch sharks, and 17.4% declared that they did not presently catch any sharks. Of the 206 fishers that reported to catch sharks, 18.4% targeted sharks and 81.6% caught sharks as bycatch. When targeted, primary use of sharks was for consumption or for sale. Sharks caught as bycatch were frequently released (69.6%), consumed (64.9%) or shared amongst the community (26.8%). Fishers’ identification based on an identification poster and DNA barcoding revealed that at least 12 species of elasmobranchs, 11 shark and one ray species (Rhynchobatus australiae) were caught. This study, which is the first focused exploration of the shark catch in Fiji’s inshore fisheries, suggests that the country’s artisanal shark fisheries are small but have the potential to develop into larger and possibly more targeted fisheries.

  4. Characteristics of the shark fisheries of Fiji.

    Science.gov (United States)

    Glaus, Kerstin B J; Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia; White, William T; Brunnschweiler, Juerg M

    2015-12-02

    Limited information is available on artisanal and subsistence shark fisheries across the Pacific. The aim of this study was to investigate Fiji's inshore fisheries which catch sharks. In January and February 2013, 253 semi-directive interviews were conducted in 117 villages and at local harbours on Viti Levu, Vanua Levu, Taveuni, Ovalau and a number of islands of the Mamanuca and Yasawa archipelagos. Of the 253 interviewees, 81.4% reported to presently catch sharks, and 17.4% declared that they did not presently catch any sharks. Of the 206 fishers that reported to catch sharks, 18.4% targeted sharks and 81.6% caught sharks as bycatch. When targeted, primary use of sharks was for consumption or for sale. Sharks caught as bycatch were frequently released (69.6%), consumed (64.9%) or shared amongst the community (26.8%). Fishers' identification based on an identification poster and DNA barcoding revealed that at least 12 species of elasmobranchs, 11 shark and one ray species (Rhynchobatus australiae) were caught. This study, which is the first focused exploration of the shark catch in Fiji's inshore fisheries, suggests that the country's artisanal shark fisheries are small but have the potential to develop into larger and possibly more targeted fisheries.

  5. Evaluation of different iron compounds in chlorotic Italian lemon trees (Citrus lemon).

    Science.gov (United States)

    Ortiz, Patricio Rivera; Castro Meza, Blanca I; de la Garza Requena, Francisco R; Flores, Guillermo Mendoza; Etchevers Barra, Jorge D

    2007-05-01

    The severe deficiency of iron or ferric chlorosis is a serious problem of most citrus trees established in calcareous soils, as a result of the low availability of iron in these soils and the poor uptake and limited transport of this nutrient in trees. The objective of this study was to evaluate the response of chlorotic Italian lemon trees (Citrus lemon) to the application of iron compounds to roots and stems. On comparing the effects of aqueous solutions of ferric citrate, ferrous sulphate and FeEDDHA chelate, applied to 20% of the roots grown in soil and sand, of trees that were planted in pots containing calcareous soil, it was observed that the chelate fully corrected ferric chlorosis, while citrate and sulphate did not solve the problem. EDDHA induced the root uptake of iron as well as the movement of the nutrient up to the leaves. With the use of injections of ferric solutions into the secondary stem of adult trees, ferric citrate corrected chlorosis but ferrous sulphate did not. The citrate ion expanded the mobility of iron within the plant, from the injection points up to the leaves, whereas the sulphate ion did not sufficiently improve the movement of iron towards the leaf mesophyll.

  6. Biodiesel from lemon and lemon grass oil and its effect on engine performance and exhaust emission

    Science.gov (United States)

    Dhivagar, R.; Sundararaj, S.; Vignesh, V. R.

    2018-03-01

    In the present scenario many developing countries are depending on oil producing nations for their fuel resources. Due to demand and scarcity of the fuel, there has been a huge increase in fuel prices. The vehicular population is also continuously increasing and becoming a great menace to peoples. This paper aims to provide an alternate solution for petroleum based fuels. It suggests that biodiesel produced from lemon and lemon grass oil can be used as an alternative fuel. This work investigates the thermal performance of four stroke diesel engine using blends of biodiesel and diesel as a fuel. Performance parameters like brake thermal efficiency, mechanical efficiency and specific fuel consumption were measured at different loads for diesel and various combination of biofuel (L10, L20, and L30). The maximum brake thermal efficiency obtained is about 26.12%for L20 which is slightly higher than that of diesel (24.91%). Engine experimental results showed that exhaust emissions including CO2 and HC were reduced by 6% and 5% for L20 mixture of biodiesel whereas CO emission was as same as diesel. However, there was increase in NOxby 26% to the diesel fuel.

  7. LEMON - LHC Era Monitoring for Large-Scale Infrastructures

    International Nuclear Information System (INIS)

    Babik, Marian; Hook, Nicholas; Lansdale, Thomas Hector; Lenkes, Daniel; Siket, Miroslav; Waldron, Denis; Fedorko, Ivan

    2011-01-01

    At the present time computer centres are facing a massive rise in virtualization and cloud computing as these solutions bring advantages to service providers and consolidate the computer centre resources. However, as a result the monitoring complexity is increasing. Computer centre management requires not only to monitor servers, network equipment and associated software but also to collect additional environment and facilities data (e.g. temperature, power consumption, cooling efficiency, etc.) to have also a good overview of the infrastructure performance. The LHC Era Monitoring (Lemon) system is addressing these requirements for a very large scale infrastructure. The Lemon agent that collects data on every client and forwards the samples to the central measurement repository provides a flexible interface that allows rapid development of new sensors. The system allows also to report on behalf of remote devices such as switches and power supplies. Online and historical data can be visualized via a web-based interface or retrieved via command-line tools. The Lemon Alarm System component can be used for notifying the operator about error situations. In this article, an overview of the Lemon monitoring is provided together with a description of the CERN LEMON production instance. No direct comparison is made with other monitoring tool.

  8. Chemicals and lemon essential oil effect on Alicyclobacillus acidoterrestris viability

    Directory of Open Access Journals (Sweden)

    Maria Cristina Maldonado

    2013-12-01

    Full Text Available Alicyclobacillus acidoterrestris is considered to be one of the important target microorganisms in the quality control of acidic canned foods. There is an urgent need to develop a suitable method for inhibiting or controlling the germination and outgrowth of A.acidoterrestris in acidic drinks. The aim of this work was to evaluate the chemicals used in the lemon industry (sodium benzoate, potassium sorbate, and lemon essential oil as a natural compound, against a strain of A.acidoterrestris in MEB medium and in lemon juice concentrate. The results pointed out that sodium benzoate (500-1000-2000 ppm and lemon essential oil (0.08- 0.12- 0.16% completely inhibited the germination of A. acidoterrestris spores in MEB medium and LJC for 11 days. Potassium sorbate (600-1200 ppm was more effective to inhibit the growth of the microbial target in lemon juice than in MEB medium. The effect of sodium benzoate, potassium sorbate and essential oil was sporostatic in MEB and LJC as they did not affect spore viability.

  9. Shark hunting - An indiscriminate trade endangering elasmobranchs to extinction

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Snigdha; Desai, S.R.; Dhargalkar, V.K.

    - head/round headed shark (Sphyrna zygaena), grey dog shark (R. acutus), sharp-nosed/yellow dog shark (S. lati- caudus) and black-finned/blacktip shark (C. melanop- terus). Most of the shark fin exports have been directed to Hong Kong and Singapore...

  10. Lemon juice has protective activity in a rat urolithiasis model

    Directory of Open Access Journals (Sweden)

    Oussama Abdelkhalek

    2007-10-01

    Full Text Available Abstract Background The use of herbal medicines (medicinal plants or phytotherapy has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation. Methods The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered nephrolithic by providing drinking water containing 0.75% ethylene glycol [v/v] (EG and 2% ammonium chloride [w/v] (AC for 10 days. In addition to EG/AC treatment, three groups of rats were also gavage-administered solutions containing 100%, 75% or 50% lemon juice [v/v] (6 μl solution/g body weight. Positive control rats were treated with EG/AC but not lemon juice. Negative control rats were provided with normal drinking water, and were administered normal water by gavage. Each group contained 6 rats. After 10 days, serum samples were collected for analysis, the left kidney was removed and assessed for calcium levels using flame spectroscopy, and the right kidney was sectioned for histopathological analysis using light microscopy. Results Analysis showed that the rats treated with EG/AC alone had higher amounts of calcium in the kidneys compared to negative control rats. This EG/AC-induced increase in kidney calcium levels was inhibited by the administration of lemon juice. Histology showed that rats treated with EG/AC alone had large deposits of calcium oxalate crystals in all parts of the kidney, and that such deposits were not present in rats also treated with either 100% or 75% lemon juice. Conclusion These data suggest that lemon juice has a protective activity against urolithiasis.

  11. Oceanic sharks clean at coastal seamount.

    Directory of Open Access Journals (Sweden)

    Simon P Oliver

    2011-03-01

    Full Text Available Interactions between pelagic thresher sharks (Alopias pelagicus and cleaner wrasse were investigated at a seamount in the Philippines. Cleaning associations between sharks and teleosts are poorly understood, but the observable interactions seen at this site may explain why these mainly oceanic sharks regularly venture into shallow coastal waters where they are vulnerable to disturbance from human activity. From 1,230 hours of observations recorded by remote video camera between July 2005 and December 2009, 97 cleaner-thresher shark events were analyzed, 19 of which were interrupted. Observations of pelagic thresher sharks interacting with cleaners at the seamount were recorded at all times of day but their frequency declined gradually from morning until evening. Cleaners showed preferences for foraging on specific areas of a thresher shark's body. For all events combined, cleaners were observed to conduct 2,757 inspections, of which 33.9% took place on the shark's pelvis, 23.3% on the pectoral fins, 22.3% on the caudal fin, 8.6% on the body, 8.3% on the head, 2.1% on the dorsal fin, and 1.5% on the gills respectively. Cleaners did not preferentially inspect thresher sharks by time of day or by shark sex, but there was a direct correlation between the amount of time a thresher shark spent at a cleaning station and the number of inspections it received. Thresher shark clients modified their behavior by "circular-stance-swimming," presumably to facilitate cleaner inspections. The cleaner-thresher shark association reflected some of the known behavioral trends in the cleaner-reef teleost system since cleaners appeared to forage selectively on shark clients. Evidence is mounting that in addition to acting as social refuges and foraging grounds for large visiting marine predators, seamounts may also support pelagic ecology by functioning as cleaning stations for oceanic sharks and rays.

  12. Games in the classroom: the market of lemons

    Directory of Open Access Journals (Sweden)

    Luis Alejandro Palacio García

    2017-05-01

    Full Text Available Classroom games are a pedagogical tool for the appropriation of concepts and enrich traditional microeconomic classes with the methodology of experimental economics. This article presents an example of participatory research that seeks to collaboratively change the learning process. We propose the lemons-market game: an experimental protocol, programed for laboratory sessions, that motivates students to debate about adverse selection due to information asymmetries, that is, about the extent to which good-quality goods are expelled from the market by inferior-quality goods (lemons.

  13. Grey Nurse Shark ( Carcharias taurus) Diving Tourism: Tourist Compliance and Shark Behaviour at Fish Rock, Australia

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks ( Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  14. Grey nurse shark (Carcharias taurus) diving tourism: Tourist compliance and shark behaviour at Fish Rock, Australia.

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  15. Cyanobacterial Neurotoxin BMAA and Mercury in Sharks

    Directory of Open Access Journals (Sweden)

    Neil Hammerschlag

    2016-08-01

    Full Text Available Sharks have greater risk for bioaccumulation of marine toxins and mercury (Hg, because they are long-lived predators. Shark fins and cartilage also contain β-N-methylamino-l-alanine (BMAA, a ubiquitous cyanobacterial toxin linked to neurodegenerative diseases. Today, a significant number of shark species have found their way onto the International Union for Conservation of Nature (IUCN Red List of Threatened Species. Many species of large sharks are threatened with extinction due in part to the growing high demand for shark fin soup and, to a lesser extent, for shark meat and cartilage products. Recent studies suggest that the consumption of shark parts may be a route to human exposure of marine toxins. Here, we investigated BMAA and Hg concentrations in fins and muscles sampled in ten species of sharks from the South Atlantic and Pacific Oceans. BMAA was detected in all shark species with only seven of the 55 samples analyzed testing below the limit of detection of the assay. Hg concentrations measured in fins and muscle samples from the 10 species ranged from 0.05 to 13.23 ng/mg. These analytical test results suggest restricting human consumption of shark meat and fins due to the high frequency and co-occurrence of two synergistic environmental neurotoxic compounds.

  16. Cyanobacterial Neurotoxin BMAA and Mercury in Sharks.

    Science.gov (United States)

    Hammerschlag, Neil; Davis, David A; Mondo, Kiyo; Seely, Matthew S; Murch, Susan J; Glover, William Broc; Divoll, Timothy; Evers, David C; Mash, Deborah C

    2016-08-16

    Sharks have greater risk for bioaccumulation of marine toxins and mercury (Hg), because they are long-lived predators. Shark fins and cartilage also contain β-N-methylamino-l-alanine (BMAA), a ubiquitous cyanobacterial toxin linked to neurodegenerative diseases. Today, a significant number of shark species have found their way onto the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Many species of large sharks are threatened with extinction due in part to the growing high demand for shark fin soup and, to a lesser extent, for shark meat and cartilage products. Recent studies suggest that the consumption of shark parts may be a route to human exposure of marine toxins. Here, we investigated BMAA and Hg concentrations in fins and muscles sampled in ten species of sharks from the South Atlantic and Pacific Oceans. BMAA was detected in all shark species with only seven of the 55 samples analyzed testing below the limit of detection of the assay. Hg concentrations measured in fins and muscle samples from the 10 species ranged from 0.05 to 13.23 ng/mg. These analytical test results suggest restricting human consumption of shark meat and fins due to the high frequency and co-occurrence of two synergistic environmental neurotoxic compounds.

  17. HMSRP Hawaiian Monk Seal Shark Predation Mitigation Shark Sightings and Incidents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data on direct sightings of large sharks around monk seal pupping sites and shark incidents on preweaned and newly weaned pups at French Frigate Shoals are entered...

  18. Lemon grass ( Cymbopogon citratus ) essential oil as a potent anti ...

    African Journals Online (AJOL)

    Conclusion: Results of the present study indicate that LGEO has a noteworthy potential for the development of drugs for the treatment of fungal infections and skin inflammation that should be explored in future studies. Keywords: lemon grass; essential oil; antifungal activity; anti-inflammatory effect; citral; aromatherapy ...

  19. Evaluation of rough lemon (Citrus jambhiri Lush.) as rootstock for ...

    African Journals Online (AJOL)

    Lakesh.Sharma

    2013-10-30

    Oct 30, 2013 ... rootstock for salinity tolerance at seedling stage under in vitro conditions ... INTRODUCTION. Around the world, citrus is one of the .... to summarize the general effect of different concentrations of NaCl on rough lemon on the ...

  20. Shark fishing effort and catch of the ragged-tooth shark Carcharias ...

    African Journals Online (AJOL)

    An integrated telephone and on-site questionnaire survey was used to estimate total shark fishing effort and specific catch of the ragged-tooth shark Carcharias taurus by coastal club-affiliated shore-anglers, primarily along the east coast of South Africa. Mean total shark fishing effort was estimated to be 37 820 fisherdays ...

  1. The relationships among lemons, limes and citron: a chromosomal comparison.

    Science.gov (United States)

    Carvalho, R; Soares Filho, W S; Brasileiro-Vidal, A C; Guerra, M

    2005-01-01

    Lemons, limes and citron constitute a group of closely related Citrus species, whose species delimitations and taxonomic relationships are unclear. In order to identify karyotypic similarities and species relationships within this group, the CMA+/DAPI- banding pattern and the distribution of the 5S and 45S rDNA sites of 10 accessions of lime, lemon, and citron were investigated. The four cultivars of C. limon analyzed showed the same pattern of CMA+ bands and rDNA sites, suggesting that they originated from a single germplasm, later differentiated by distinct somatic mutations. The lemons C. jambhiri, C. limonia and C. volkameriana displayed karyotypes very similar to each other, but they differed from C. limon by the absence of a single chromosome with one band in each telomere. The limes, C. aurantifolia and C. limettioides, seemed less related to each other and exhibited different heteromorphic chromosome pairs. In C. aurantifolia, the presence of a chromosome type unknown in all other Citrus species cytologically known so far supports the assumption that this accession may be derived from a hybrid with a species from the subgenus Papeda or from another genus. Citrus medica was the only homozygous accession of this group and all of its chromosome types were clearly represented in limes and lemons, some of them forming heteromorphic pairs. The analysis of the distribution of rDNA sites allowed a further refinement of the comparison among accessions. The lemons and limes were heterozygous for all rDNA sites, whereas C. medica was entirely homozygous. These data support the hypothesis that C. medica is a true species while the other nine accessions are hybrids. Copyright 2005 S. Karger AG, Basel.

  2. Morphological and genetic analysis of three new species of Ceratomyxa Thélohan, 1892 (Myxozoa: Myxosporea) from carcharhinid sharks off Australia.

    Science.gov (United States)

    Gleeson, Ricky; Adlard, Robert

    2011-10-01

    Three new species of Ceratomyxa Thélohan, 1892 are described from the gall-bladders of two species of carcharhinid sharks collected off Heron and Lizard Islands on the Great Barrier Reef, Australia. Ceratomyxa carcharhini n. sp. and C. melanopteri n. sp. are described from Carcharhinus melanopterus (Quoy & Gaimard), and Ceratomyxa negaprioni n. sp. is described from Negaprion acutidens (Rüppell). These species are the first ceratomyxids reported from Australian elasmobranchs, and this is the first paper to formally characterise a novel Ceratomyxa species from an elasmobranch using both morphology and small subunit ribosomal DNA sequence data. Maximum parsimony and Bayesian inference analyses of the SSU rDNA dataset revealed that ceratomyxids from elasmobranchs form a sister clade to that of species infecting marine teleosts and Palliatus indecorus Schulman, Kovaleva & Dubina, 1979. Furthermore, the only sequenced freshwater ceratomyxid, Ceratomyxa shasta Noble, 1950, fell outside the overall marine ceratomyxid clade. These data show that Ceratomyxa, as currently recognised, is polyphyletic and ignites discussion on whether Ceratomyxa should be split. However, further taxon sampling, particularly in freshwater systems, is required to establish relevant biological divisions within the genus.

  3. Sharks and people: insight into the global practices of tourism operators and their attitudes to shark behaviour.

    Science.gov (United States)

    Richards, Kirsty; O'Leary, Bethan C; Roberts, Callum M; Ormond, Rupert; Gore, Mauvis; Hawkins, Julie P

    2015-02-15

    Shark tourism is a popular but controversial activity. We obtained insights into this industry via a global e-mailed questionnaire completed by 45 diving/snorkelling operators who advertised shark experiences (shark operators) and 49 who did not (non-shark operators). 42% of shark operators used an attractant to lure sharks and 93% stated they had a formal code of conduct which 86% enforced "very strictly". While sharks were reported to normally ignore people, 9 operators had experienced troublesome behaviour from them. Whilst our research corroborates previous studies indicating minimal risk to humans from most shark encounters, a precautionary approach to provisioning is required to avoid potential ecological and societal effects of shark tourism. Codes of conduct should always stipulate acceptable diver behaviour and appropriate diver numbers and shark operators should have a moral responsibility to educate their customers about the need for shark conservation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Lemon peel oil – A novel renewable alternative energy source for diesel engine

    International Nuclear Information System (INIS)

    Ashok, B.; Thundil Karuppa Raj, R.; Nanthagopal, K.; Krishnan, Rahul; Subbarao, Rayapati

    2017-01-01

    Highlights: • Novel biofuel is extracted from lemon peels through steam distillation process. • Lemon peel oil is found to be a potential, renewable alternate eco-friendly fuel. • Significant vibration is observed with 100% lemon peel oil. • Reduction of CO, HC and smoke emission are observed with lemon peel oil blends. • Lemon peel oil blends are showed higher brake thermal efficiency than diesel fuel. - Abstract: The present research work has embarked on to exploit the novel renewable and biodegradable source of energy from lemon fruit rinds. A systematic approach has been made in this study to find the suitability of lemon peel oil for internal combustion engines and gensets applications. Extracted lemon peel oil is found to exhibit comparatively very low viscosity, flash point and boiling point than that of conventional diesel. Various blends of lemon peel oil have been prepared with conventional diesel with volumetric concentration of 20%, 40%, 50% and 100% and their physical and chemical properties are evaluated for its suitability in direct injection diesel engine. Lower cetane index of lemon peel oil significantly influences the ignition delay period and peak heat release rate that lead to the penalty in NOx emissions. Interestingly, the diesel engine performance characteristics have been improved to a remarkable level with higher proportions of lemon peel oil in the blends. In addition, the reduction of BSCO, BSHC and smoke emission is proportional to the lemon oil concentration in the blends. Overall diesel engine characteristics indicated that lemon peel oil can partially or completely replace the petroleum diesel usage to a great extent in developing countries like India.

  5. Pelagic shark fisheries of Indonesia's Eastern Indian Ocean ...

    African Journals Online (AJOL)

    Sharks are commonly caught in Indonesian waters both by target fisheries and as bycatch. Fishers targeting sharks mostly employ drift longlines, whereas tuna longlines and gillnets are the gear mostly responsible for shark bycatch. Our studies on shark fisheries have been conducted since 2006 and have focused on the ...

  6. Lemon juice has protective activity in a rat urolithiasis model

    OpenAIRE

    Touhami, Mohammed; Laroubi, Amine; Elhabazi, Khadija; Loubna, Farouk; Zrara, Ibtissam; Eljahiri, Younes; Oussama, Abdelkhalek; Grases, Félix; Chait, Abderrahman

    2007-01-01

    Abstract Background The use of herbal medicines (medicinal plants or phytotherapy) has recently gained popularity in Europe and the United States. Nevertheless the exact mechanism of the preventive effects of these products is still far to be clearly established, being its knowledge necessary to successfully apply these therapies to avoid stone formation. Methods The effect of oral lemon juice administration on calcium oxalate urolithiasis was studied in male Wistar rats. Rats were rendered n...

  7. Natural spread of Citrus tristeza virus in lemon varieties

    Directory of Open Access Journals (Sweden)

    Julia Figueroa

    2012-06-01

    Full Text Available Natural spread of Citrus tristeza virus (CTV was monitored in different lemon varieties derived from shoot tip grafted (STG selections proven to be free of CTV before planting. The trial was planted in November, 2007, with a randomized four-block design with four replications. This experiment was originally established to compare selected clones with their duplicates recovered by STG. The selected clones were originally nucellar clones kept in the germplasm bank in the field for 30 to 40 years, so the plants were naturally infected with CTV. The lemon varieties tested were two lines of both Frost Eureka and Limoneira 8A Lisbon and one line of Feminello Santa Teresa and Genoa EEAT. Plants were grafted on Poncirus trifoliata Flying Dragon, except for Eureka lemon, which was grafted on 79 AC [Citrus reshni x (C. paradisi x P. Trifoliata]. Direct immunoprinting-ELISA with 3DF1+3CA5 monoclonal antibodies (Plant Print Diagnostics, Valencia was used to determine the presence of CTV in field samples. Each sample was composed of four young shoots collected from the four sides of each tree. Two diagnoses were performed, one in September 2009 and another in September 2010. STG trees showed significant differences in CTV infection among them. The variety most infected with CTV was Limoneria 8 A and the least infected was Feminello Santa Teresa. Infected plants were found in a random distribution in the plot. All selected lemon trees were CTV positive. CTV spread will be monitored until 100% of all varieties show positive.

  8. Anti-Stress Effects of Lemon Balm-Containing Foods

    Directory of Open Access Journals (Sweden)

    Andrew Scholey

    2014-10-01

    Full Text Available Lemon balm (Melissa officinalis has been used historically and contemporarily as a modulator of mood and cognitive function, with anxiolytic effects following administration of capsules, coated tablets and topical application. Following a pilot study with lemon balm extract administered as a water based drink, which confirmed absorption of rosmarinic acid effects on mood and cognitive function, we conducted two similar double-blind, placebo-controlled, crossover studies. These evaluated the mood and cognitive effects of a standardised M. officinalis preparation administered in palatable forms in a beverage and in yoghurt. In each study a cohort of healthy young adults’ self-rated aspects of mood were measured before and after a multi-tasking framework (MTF administered one hour and three hours following one of four treatments. Both active lemon balm treatments were generally associated with improvements in mood and/or cognitive performance, though there were some behavioral “costs” at other doses and these effects depended to some degree on the delivery matrix.

  9. Lemon Effect of Green Agricultural Products and Its Marketing Strategy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The paper introduces the lemon effect of green agricultural products,analyzes the formation reasons of the lemon effect of green agricul-tural products and summarizes problems brought by the effect,such as malicious deception and high price.The paper proposes countermeasures toavoid the lemon effect of green agricultural products from a perspective of marketing.The first is to strengthen the quality supervision of green agri-cultural products,upgrade the quality of products,and build up branded products.The government should foster the main body of the products andguide the main body to realize the importance of brand construction and management.The second is to construct a sales channel system of greenagricultural products,making use of the trading center of modern green agricultural products to sell products,developing a long term partnershipwith processing industries,big supermarket and restaurants,making use of internet and selling products online and offline.The third is to propagatethe products.Make a good use of advertisement,personal sales,propagation and public relations to accelerate the healthy development of greenagricultural market.

  10. Calcitonin produces hypercalcemia in leopard sharks.

    Science.gov (United States)

    Glowacki, J; O'Sullivan, J; Miller, M; Wilkie, D W; Deftos, L J

    1985-02-01

    Calcitonin was detected by RIA in sera from four marine species, leopard sharks (Triakis semifasciata), horn sharks (Heterodontus francisci), thornback rays (Platyrhinoides triseriata), and kelp bass (Paralabrax clathratus). These animals have levels of calcitonin and calcium higher than freshwater and terrestrial species have. The administration of salmon calcitonin to bass (4 micrograms/kg BW) produced hypocalcemia and hypophosphatemia as has been reported for other bony vertebrates. In marked contrast, calcitonin produced a prompt hypercalcemia in sharks; the average was 9.8% increase in serum calcium in nine animals with no attendant change in phosphorus. These findings demonstrate that calcitonin can increase serum calcium in sharks. Because shark skeleton is composed of cartilage, this hypercalcemic effect of calcitonin does not require a bony skeleton.

  11. How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour

    OpenAIRE

    Kempster, Ryan M.; Egeberg, Channing A.; Hart, Nathan S.; Ryan, Laura; Chapuis, Lucille; Kerr, Caroline C.; Schmidt, Carl; Huveneers, Charlie; Gennari, Enrico; Yopak, Kara E.; Meeuwig, Jessica J.; Collin, Shaun P.

    2016-01-01

    Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scienti...

  12. Shark Spotters: Successfully reducing spatial overlap between white sharks (Carcharodon carcharias) and recreational water users in False Bay, South Africa.

    Science.gov (United States)

    Engelbrecht, Tamlyn; Kock, Alison; Waries, Sarah; O'Riain, M Justin

    2017-01-01

    White sharks (Carcharodon carcharias) are apex predators that play an important role in the structure and stability of marine ecosystems. Despite their ecological importance and protected status, white sharks are still subject to lethal control to reduce the risk of shark bites for recreational water users. The Shark Spotters program, pioneered in Cape Town, South Africa, provides a non-lethal alternative for reducing the risk of human-shark conflict. In this study we assessed the efficacy of the Shark Spotters program in reducing overlap between water users and white sharks at two popular beaches in False Bay, South Africa. We investigated seasonal and diel patterns in water use and shark presence at each beach, and thereafter quantified the impact of different shark warnings from shark spotters on water user abundance. We also assessed the impact of a fatal shark incident on patterns of water use. Our results revealed striking diel and seasonal overlap between white sharks and water users at both beaches. Despite this, there was a low rate of shark-human incidents (0.5/annum) which we attribute partly to the success of the Shark Spotters program. Shark spotters use visual (coloured flags) and auditory (siren) cues to inform water users of risk associated with white shark presence in the surf zone. Our results showed that the highest risk category (denoted by a white flag and accompanying siren) caused a significant reduction in water user abundance; however the secondary risk category (denoted by a red flag with no siren) had no significant effect on water users. A fatal shark incident was shown to negatively impact the number of water users present for at least three months following the incident. Our results indicate that the Shark Spotters program effectively reduces spatial overlap between white sharks and water users when the risk of conflict is highest.

  13. The Ecological Role of Sharks on Coral Reefs.

    Science.gov (United States)

    Roff, George; Doropoulos, Christopher; Rogers, Alice; Bozec, Yves-Marie; Krueck, Nils C; Aurellado, Eleanor; Priest, Mark; Birrell, Chico; Mumby, Peter J

    2016-05-01

    Sharks are considered the apex predator of coral reefs, but the consequences of their global depletion are uncertain. Here we explore the ecological roles of sharks on coral reefs and, conversely, the importance of reefs for sharks. We find that most reef-associated shark species do not act as apex predators but instead function as mesopredators along with a diverse group of reef fish. While sharks perform important direct and indirect ecological roles, the evidence to support hypothesised shark-driven trophic cascades that benefit corals is weak and equivocal. Coral reefs provide some functional benefits to sharks, but sharks do not appear to favour healthier reef environments. Restoring populations of sharks is important and can yet deliver ecological surprise. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The Effect of Background Music in Shark Documentaries on Viewers' Perceptions of Sharks.

    Directory of Open Access Journals (Sweden)

    Andrew P Nosal

    Full Text Available Despite the ongoing need for shark conservation and management, prevailing negative sentiments marginalize these animals and legitimize permissive exploitation. These negative attitudes arise from an instinctive, yet exaggerated fear, which is validated and reinforced by disproportionate and sensationalistic news coverage of shark 'attacks' and by highlighting shark-on-human violence in popular movies and documentaries. In this study, we investigate another subtler, yet powerful factor that contributes to this fear: the ominous background music that often accompanies shark footage in documentaries. Using three experiments, we show that participants rated sharks more negatively and less positively after viewing a 60-second video clip of swimming sharks set to ominous background music, compared to participants who watched the same video clip set to uplifting background music, or silence. This finding was not an artifact of soundtrack alone because attitudes toward sharks did not differ among participants assigned to audio-only control treatments. This is the first study to demonstrate empirically that the connotative attributes of background music accompanying shark footage affect viewers' attitudes toward sharks. Given that nature documentaries are often regarded as objective and authoritative sources of information, it is critical that documentary filmmakers and viewers are aware of how the soundtrack can affect the interpretation of the educational content.

  15. The Effect of Background Music in Shark Documentaries on Viewers' Perceptions of Sharks.

    Science.gov (United States)

    Nosal, Andrew P; Keenan, Elizabeth A; Hastings, Philip A; Gneezy, Ayelet

    2016-01-01

    Despite the ongoing need for shark conservation and management, prevailing negative sentiments marginalize these animals and legitimize permissive exploitation. These negative attitudes arise from an instinctive, yet exaggerated fear, which is validated and reinforced by disproportionate and sensationalistic news coverage of shark 'attacks' and by highlighting shark-on-human violence in popular movies and documentaries. In this study, we investigate another subtler, yet powerful factor that contributes to this fear: the ominous background music that often accompanies shark footage in documentaries. Using three experiments, we show that participants rated sharks more negatively and less positively after viewing a 60-second video clip of swimming sharks set to ominous background music, compared to participants who watched the same video clip set to uplifting background music, or silence. This finding was not an artifact of soundtrack alone because attitudes toward sharks did not differ among participants assigned to audio-only control treatments. This is the first study to demonstrate empirically that the connotative attributes of background music accompanying shark footage affect viewers' attitudes toward sharks. Given that nature documentaries are often regarded as objective and authoritative sources of information, it is critical that documentary filmmakers and viewers are aware of how the soundtrack can affect the interpretation of the educational content.

  16. Regional movements of the tiger shark, Galeocerdo cuvier, off Northeastern Brazil: inferences regarding shark attack hazard.

    Science.gov (United States)

    Hazin, Fábio H V; Afonso, André S; De Castilho, Pedro C; Ferreira, Luciana C; Rocha, Bruno C L M

    2013-09-01

    An abnormally high shark attack rate verified off Recife could be related to migratory behavior of tiger sharks. This situation started after the construction of the Suape port to the south of Recife. A previous study suggested that attacking sharks could be following northward currents and that they were being attracted shoreward by approaching vessels. In this scenario, such northward movement pattern could imply a higher probability of sharks accessing the littoral area of Recife after leaving Suape. Pop-up satellite archival tags were deployed on five tiger sharks caught off Recife to assess their movement patterns off northeastern Brazil. All tags transmitted from northward latitudes after 7-74 days of freedom. The shorter, soak distance between deployment and pop-up locations ranged between 33-209 km and implied minimum average speeds of 0.02-0.98 km.h-1. Both pop-up locations and depth data suggest that tiger shark movements were conducted mostly over the continental shelf. The smaller sharks moved to deeper waters within 24 hours after releasing, but they assumed a shallower (shark movements in the South Atlantic, this study also adds new information for the reasoning of the high shark attack rate verified in this region.

  17. Physico-chemical and viscoelastic properties of high pressure homogenized lemon peel fiber fraction suspensions obtained after sequential pectin extraction

    NARCIS (Netherlands)

    Willemsen, K.L.D.D.; Panozzo, A.; Moelants, K.; Debon, S.J.J.; Desmet, C.; Cardinaels, R.M.; Moldenaers, P.; Wallecan, J.; Hendrickx, M.E.G.

    2017-01-01

    The viscoelastic properties of high pressure homogenized lemon peel cell wall fiber suspensions, obtained after sequential selective pectin extraction, were investigated in the current study. For comparison, a general pectin extraction was additionally performed on lemon peel under acid thermal

  18. Effects of lemon juice on the reproductive hormones of female wistar ...

    African Journals Online (AJOL)

    Lemon juice has been used by Mediterranean women as their main method of contraception. In the Nigerian traditional society, women of child bearing age are advised against the intake of lemon if they want to conceive because it is believed to have contraceptive effect. This necessitated the investigation of the effect of ...

  19. Protective Effects of Lemon Juice on Alcohol-Induced Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Tong Zhou

    2017-01-01

    Full Text Available Chronic excessive alcohol consumption (more than 40–80 g/day for males and more than 20–40 g/day for females could induce serious liver injury. In this study, effects of lemon juice on chronic alcohol-induced liver injury in mice were evaluated. The serum biochemical profiles and hepatic lipid peroxidation levels, triacylglycerol (TG contents, antioxidant enzyme activities, and histopathological changes were examined for evaluating the hepatoprotective effects of lemon juice in mice. In addition, the in vitro antioxidant capacities of lemon juice were determined. The results showed that lemon juice significantly inhibited alcohol-induced increase of alanine transaminase (ALT, aspartate transaminase (AST, hepatic TG, and lipid peroxidation levels in a dose-dependent manner. Histopathological changes induced by alcohol were also remarkably improved by lemon juice treatment. These findings suggest that lemon juice has protective effects on alcohol-induced liver injury in mice. The protective effects might be related to the antioxidant capacity of lemon juice because lemon juice showed in vitro antioxidant capacity.

  20. 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

  1. Methylmercury in dried shark fins and shark fin soup from American restaurants.

    Science.gov (United States)

    Nalluri, Deepthi; Baumann, Zofia; Abercrombie, Debra L; Chapman, Demian D; Hammerschmidt, Chad R; Fisher, Nicholas S

    2014-10-15

    Consumption of meat from large predatory sharks exposes human consumers to high levels of toxic monomethylmercury (MMHg). There also have been claims that shark fins, and hence the Asian delicacy shark fin soup, contain harmful levels of neurotoxic chemicals in combination with MMHg, although concentrations of MMHg in shark fins are unknown. We measured MMHg in dried, unprocessed fins (n=50) of 13 shark species that occur in the international trade of dried shark fins as well as 50 samples of shark fin soup prepared by restaurants from around the United States. Concentrations of MMHg in fins ranged from 9 to 1720 ng/g dry wt. MMHg in shark fin soup ranged from sharks such as hammerheads (Sphyrna spp.). Consumption of a 240 mL bowl of shark fin soup containing the average concentration of MMHg (4.6 ng/mL) would result in a dose of 1.1 μg MMHg, which is 16% of the U.S. EPA's reference dose (0.1 μg MMHg per 1 kg per day in adults) of 7.4 μg per day for a 74 kg person. If consumed, the soup containing the highest measured MMHg concentration would exceed the reference dose by 17%. While shark fin soup represents a potentially important source of MMHg to human consumers, other seafood products, particularly the flesh of apex marine predators, contain much higher MMHg concentrations and can result in substantially greater exposures of this contaminant for people. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Size of the great white shark (carcharodon).

    Science.gov (United States)

    Randall, J E

    1973-07-13

    The maximum length of 36.5 feet (11.1 meters) attributed to the white shark (Carcharodon carcharias) by Günther and others is a mistake. Examination of the jaws and teeth of the specimen referred to by Günther and comparison with the jaws of white sharks of known length revealed a length of about 17 feet ( approximately 5 meters). The largest white shark reliably measured was a 21-foot (6.4-meter) individual from Cuba. Bites on whale carcasses found off southern Australia suggest that white sharks as long as 25 or 26 feet (7 (1/2) or 8 meters) exist today. The size of extinct Carcharodon has also been grossly exaggerated. Based on a projection of a curve of tooth size of Recent Carcharodon carcharias, the largest fossil Carcharodon were about 43 feet ( approximately 13 meters) long.

  3. Atlantic Sharpnose Shark Reproductive Biology Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Reproductive data from Atlantic sharpnose sharks were collected from specimens captured throughout the northern Gulf of Mexico on various research vessels. Data...

  4. Cooperative Shark Mark Recapture Database (MRDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Shark Mark Recapture Database is a Cooperative Research Program database system used to keep multispecies mark-recapture information in a common format for...

  5. Preferred conservation policies of shark researchers.

    Science.gov (United States)

    Shiffman, David S; Hammerschlag, Neil

    2016-08-01

    There is increasing concern about the conservation status of sharks. However, the presence of numerous different (and potentially mutually exclusive) policies complicates management implementation and public understanding of the process. We distributed an online survey to members of the largest professional shark and ray research societies to assess member knowledge of and attitudes toward different conservation policies. Questions covered society member opinions on conservation and management policies, personal histories of involvement in advocacy and management, and perceptions of the approach of conservation nongovernmental organizations (NGOs) to shark conservation. One hundred and two surveys were completed (overall response rate 21%). Respondents considered themselves knowledgeable about and actively involved in conservation and management policy; a majority believed scientists have a responsibility to advocate for conservation (75%), and majorities have sent formal public comments to policymakers (54%) and included policy suggestions in their papers (53%). They believe sustainable shark fisheries are possible, are currently happening today (in a few places), and should be the goal instead of banning fisheries. Respondents were generally less supportive of newer limit-based (i.e., policies that ban exploitation entirely without a species-specific focus) conservation policy tools, such as shark sanctuaries and bans on the sale of shark fins, than of target-based fisheries management tools (i.e., policies that allow for sustainable harvest of species whose populations can withstand it), such as fishing quotas. Respondents were generally supportive of environmental NGO efforts to conserve sharks but raised concerns about some NGOs that they perceived as using incorrect information and focusing on the wrong problems. Our results show there is an ongoing debate in shark conservation and management circles relative to environmental policy on target-based natural

  6. Seedless induced mutant in highly seeded lemon (Citrus limon)

    International Nuclear Information System (INIS)

    Spiegel-Roy, P.; Vardi, Aliza; Elhanati, A.

    1990-01-01

    Full text: We have reported earlier on the induction of a seedless mutant in ''Eureka'' lemon. Further irradiation work with gamma rays was performed with another lemon cultivar, ''Israeli Villafranca''. This highly prolific cultivar has usually up to 25 seeds per fruit. Budwood of ''Villafranca'' was exposed to 50 Gy gamma rays from a Co source at the Nuclear Soreq Centre (by courtesy of Mr. R. Padova). Buds from M 1 V 1 plants (usually buds 3 to 15) were individually budded in the nursery on sour orange, as well as buds from non-irradiated material. Out of 120 M 1 V 2 plants grown in the field at 3x2 m spacing one tree bore completely seedless fruit. Fruit on adjacent trees had 22 seeds on the average. The selected tree has been observed for two seasons and found to bear normal seedless fruit. M 1 V 3 trees from budwood of the selected original tree have been raised. Some of these have started bearing. Nearly all fruits are completely seedless, with a maximum number of 1 seed per fruit. (author)

  7. Evolutionary immunology. A boost to immunity from nurse sharks.

    Science.gov (United States)

    Parham, P

    1995-07-01

    A study of the nurse shark has revealed a type of rearranging gene that has yet to be seen in mammals; it encodes a secreted 'new antigen receptor' which, unlike shark immunoglobulin, revels in somatic hypermutation.

  8. Shark predation on Indian Ocean bottlenose dolphins TUTSiops ...

    African Journals Online (AJOL)

    1988-10-24

    Oct 24, 1988 ... Four species of shark, the Zambesi (Carcharhinus leucas), the tiger (Galeocerdo ... level of shark predation on bottlenose dolphins was unknown it appeared to ..... possible examples of these adaptations. Acknowledgments.

  9. "Shark is the man!": ethnoknowledge of Brazil's South Bahia fishermen regarding shark behaviors.

    Science.gov (United States)

    Barbosa-Filho, Márcio Luiz Vargas; Schiavetti, Alexandre; Alarcon, Daniela Trigueirinho; Costa-Neto, Eraldo Medeiros

    2014-07-03

    Fishermen's knowledge is a source of indispensable information in decision-making processes related to efforts to stimulate the management and conservation of fishing resources, especially in developing countries. This study analyzed the knowledge of fishermen from three municipal areas of Bahia in northeast Brazil regarding the behavior repertoire of sharks and the possible influence that these perceptions may have on the inclination to preserve these animals. This is a pioneering study on the ethnobiological aspects of elasmobranchs in Brazil. Open, semi-structured interviews with shark fishing specialists were conducted between September 2011 and October 2012. The interviews addressed the fishermen's profile, fishing techniques and knowledge about sharks, focusing on the behaviours exhibited by sharks. The data were analysed with quantitative approach and conducted with the use of descriptive statistical techniques. Sixty-five fishermen were interviewed. They descend from the rafting subculture of Brazil's northeast, which has historically been disregarded by public policies addressing the management and conservation of fishing resources. The fishing fleet involved in shark fishing includes rafts, fishing boats and lobster boats equipped with fishing lines, gillnets, longlines and "esperas". The informers classified sharks' behaviour repertoire into 19 ethological categories, related especially to feeding, reproduction, and social and migratory behaviours. Because they identify sharks as predators, the detailed recognition of the behaviours exhibited is crucial both for an efficient catch and to avoid accidents. Therefore, this knowledge is doubly adaptive as it contributes to safer, more lucrative fishing. A feeling of respect for sharks predominates, since informers recognize the ecological role of these animals in marine ecosystems, attributing them the status of leader (or "the man") in the sea. This work demonstrates the complexity and robustness of

  10. Survey of shark fisheries and preparation of a National Plan of Action (NPOA) for conservation and management of shark resources in Bangladesh

    OpenAIRE

    2014-01-01

    The report presents; terms of reference; work progress; surveys of shark fishers and traders; shark biodiversity survey; and a National Plan of Action (NPOA) for conservation and management of shark resources in Bangladesh.

  11. Fisheries management and conservation of sharks in Indonesia ...

    African Journals Online (AJOL)

    Indonesian waters have a high diversity of sharks and rays, with at least 118 species belonging to 25 families found throughout the vast archipelago. Indonesia also has the highest shark landings globally and nearly all high-value shark species are overexploited and could be considered threatened. This situation is of ...

  12. White sharks Carcharodon carcharias at Bird Island, Algoa Bay ...

    African Journals Online (AJOL)

    We present the first quantitative study of the occurrence, size and sex of white sharks Carcharodon carcharias at Bird Island, Algoa Bay. Twenty-two boat trips were made to Bird Island between November 2009 and October 2011 to chum for sharks. A total of 53 sharks was observed over the study period, ranging in size ...

  13. A global perspective on the trophic geography of sharks

    DEFF Research Database (Denmark)

    Bird, Christopher S.; Verissimo, Ana; Magozzi, Sarah

    2018-01-01

    Sharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural trait...

  14. 77 FR 57022 - Drawbridge Operation Regulation; Shark River, Avon, NJ

    Science.gov (United States)

    2012-09-17

    ... Operation Regulation; Shark River, Avon, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation... across the Shark River (South Channel), at Avon Township, NJ. This deviation is necessary to facilitate stringer replacement on the Shark River railroad bridge. This temporary deviation will allow the...

  15. 78 FR 77591 - Drawbridge Operation Regulation; Shark River, NJ

    Science.gov (United States)

    2013-12-24

    ... Operation Regulation; Shark River, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge... governs the bascule span of the Route 71 Bridge across Shark River (South Channel), mile 0.8, at Belmar... motor seals and instrumentation on the bridge. The Route 71 Bridge across Shark River (South Channel...

  16. 78 FR 3836 - Drawbridge Operation Regulation; Shark River, Avon, NJ

    Science.gov (United States)

    2013-01-17

    ... Operation Regulation; Shark River, Avon, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from... and the railroad bridge, mile 0.9 both of which are across the Shark River (South Channel), at Avon Township, NJ. This deviation is necessary to facilitate machinery replacement on the Shark River railroad...

  17. Recovery of human remains after shark attack.

    Science.gov (United States)

    Byard, Roger W; James, Ross A; Heath, Karen J

    2006-09-01

    Two cases of fatal shark attack are reported where the only tissues recovered were fragments of lung. Case 1: An 18-year-old male who was in the sea behind a boat was observed by friends to be taken by a great white shark (Carcharodon carcharias). The shark dragged him under the water and then, with a second shark, dismembered the body. Witnesses noted a large amount of blood and unrecognizable body parts coming to the surface. The only tissues recovered despite an intensive beach and sea search were 2 fragments of lung. Case 2: A 19-year-old male was attacked by a great white shark while diving. A witness saw the shark swim away with the victim's body in its mouth. Again, despite intensive beach and sea searches, the only tissue recovered was a single piece of lung, along with pieces of wetsuit and diving equipment. These cases indicate that the only tissue to escape being consumed or lost in fatal shark attacks, where there is a significant attack with dismemberment and disruption of the integrity of the body, may be lung. The buoyancy of aerated pulmonary tissue ensures that it rises quickly to the surface, where it may be recovered by searchers soon after the attack. Aeration of the lung would be in keeping with death from trauma rather than from drowning and may be a useful marker in unwitnessed deaths to separate ante- from postmortem injury, using only relatively small amounts of tissues. Early organ recovery enhances the identification of human tissues as the extent of morphologic alterations by putrefactive processes and sea scavengers will have been minimized. DNA testing is also possible on such recovered fragments, enabling confirmation of the identity of the victim.

  18. Fatal tiger shark, Galeocerdo cuvier attack in New Caledonia erroneously ascribed to great white shark, Carcharodon carcharias

    OpenAIRE

    Tirard, P.; Maillaud, C.; Borsa, Philippe

    2015-01-01

    International audience; To understand the causes and patterns of shark attacks on humans, accurate identification of the shark species involved is necessary. Often, the only reliable evidence for this comes from the characteristics of the wounds exhibited by the victim. The present case report is intended as a reappraisal of the Luengoni, 2007 case (International Shark Attack File no. 4299) where a single shark bite provoked the death of a swimmer by haemorrhagic shock. Our examination of the...

  19. Something worth remembering: visual discrimination in sharks.

    Science.gov (United States)

    Fuss, Theodora; Schluessel, Vera

    2015-03-01

    This study investigated memory retention capabilities of juvenile gray bamboo sharks (Chiloscyllium griseum) using two-alternative forced-choice experiments. The sharks had previously been trained in a range of visual discrimination tasks, such as distinguishing between squares, triangles and lines, and their corresponding optical illusions (i.e., the Kanizsa figures or Müller-Lyer illusions), and in the present study, we tested them for memory retention. Despite the absence of reinforcement, sharks remembered the learned information for a period of up to 50 weeks, after which testing was terminated. In fish, as in other vertebrates, memory windows vary in duration depending on species and task; while it may seem beneficial to retain some information for a long time or even indefinitely, other information may be forgotten more easily to retain flexibility and save energy. The results of this study indicate that sharks are capable of long-term memory within the framework of selected cognitive skills. These could aid sharks in activities such as food retrieval, predator avoidance, mate choice or habitat selection and therefore be worth being remembered for extended periods of time. As in other cognitive tasks, intraspecific differences reflected the behavioral breadth of the species.

  20. Bacteriology of the teeth from a great white shark: potential medical implications for shark bite victims.

    Science.gov (United States)

    Buck, J D; Spotte, S; Gadbaw, J J

    1984-11-01

    Bacteria were cultured for the first time from the teeth of a great white shark (Carcharodon carcharias). Isolates included Vibrio alginolyticus, Vibrio fluvialis, Vibrio parahaemolyticus, and other genera. All are common in the marine environment and some may be associated with wound infections in humans. Shark bite lacerations may serve as a source of these potentially infectious bacteria, particularly Vibrio spp., and should be treated immediately. Antibiotic susceptibility patterns are shown for representatives of Vibrio isolates and indicate that a variety of new agents may be appropriate chemotherapy for shark bite victims.

  1. Shark tales: a molecular species-level phylogeny of sharks (Selachimorpha, Chondrichthyes).

    Science.gov (United States)

    Vélez-Zuazo, Ximena; Agnarsson, Ingi

    2011-02-01

    Sharks are a diverse and ecologically important group, including some of the ocean's largest predatory animals. Sharks are also commercially important, with many species suffering overexploitation and facing extinction. However, despite a long evolutionary history, commercial, and conservation importance, phylogenetic relationships within the sharks are poorly understood. To date, most studies have either focused on smaller clades within sharks, or sampled taxa sparsely across the group. A more detailed species-level phylogeny will offer further insights into shark taxonomy, provide a tool for comparative analyses, as well as facilitating phylogenetic estimates of conservation priorities. We used four mitochondrial and one nuclear gene to investigate the phylogenetic relationships of 229 species (all eight Orders and 31 families) of sharks, more than quadrupling the number of taxon sampled in any prior study. The resulting Bayesian phylogenetic hypothesis agrees with prior studies on the major relationships of the sharks phylogeny; however, on those relationships that have proven more controversial, it differs in several aspects from the most recent molecular studies. The phylogeny supports the division of sharks into two major groups, the Galeomorphii and Squalimorphii, rejecting the hypnosqualean hypothesis that places batoids within sharks. Within the squalimorphs the orders Hexanchiformes, Squatiniformes, Squaliformes, and Pristiophoriformes are broadly monophyletic, with minor exceptions apparently due to missing data. Similarly, within Galeomorphs, the orders Heterodontiformes, Lamniformes, Carcharhiniformes, and Orectolobiformes are broadly monophyletic, with a couple of species 'misplaced'. In contrast, many of the currently recognized shark families are not monophyletic according to our results. Our phylogeny offers some of the first clarification of the relationships among families of the order Squaliformes, a group that has thus far received relatively

  2. 78 FR 59878 - Atlantic Highly Migratory Species; Commercial Atlantic Aggregated Large Coastal Shark (LCS...

    Science.gov (United States)

    2013-09-30

    ... Coastal Shark (LCS), Atlantic Hammerhead Shark, Atlantic Blacknose Shark, and Atlantic Non-Blacknose Small Coastal Shark (SCS) Management Groups AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... closing the commercial management groups for aggregated LCS and hammerhead sharks in the Atlantic region...

  3. Cross matching of blood in carcharhiniform, lamniform, and orectolobiform sharks.

    Science.gov (United States)

    Hadfield, Catherine A; Haines, Ashley N; Clayton, Leigh A; Whitaker, Brent R

    2010-09-01

    The transfusion of whole blood in elasmobranchs could provide cardiovascular support following hemorrhage. Since donor and recipient compatibility is not known, a technique was established to allow cross matching of red blood cells and serum in sharks. Cross matching was carried out among 19 individuals from seven species: the nurse shark (Ginglymostoma cirratum), sandbar shark (Carcharhinus plumbeus), sandtiger shark (Carcharias taurus), white-spotted bamboo shark (Chiloscyllium plagiosum), brown-banded bamboo shark (Chiloscyllium punctatum), zebra shark (Stegostoma fasciatum), and spotted wobbegong (Orectolobus maculatus). Negative cross-matches showed no agglutination or hemolysis, suggesting that donor and recipient would be compatible. Cross-matches between conspecifics were all negative (sandbar, sandtiger, nurse, and white-spotted bamboo sharks). All cross-matches between sandbar and sandtiger sharks were also negative. Positive crossmatches consisted of agglutination or hemolysis of red blood cells, suggesting that the donor and recipient would be incompatible. Strong positive reactions occurred, for example, with red blood cells from sandtiger and sandbar sharks and serum from nurse sharks. Cross matching should be carried out in elasmobranchs prior to any blood transfusion.

  4. On Sharks, Trolls, and Other Patent Animals

    DEFF Research Database (Denmark)

    Reitzig, Markus; Henkel, Joachim; Heath, Christopher

    2007-01-01

    Patent trolls (or sharks) are small patent holding individuals or firms who trap R&D intense manufacturers in patent infringement situations in order to receive damage awards for the illegitimate use of their technology. While of great concern to management, their existence and impact for both...... corporate decision makers and policy makers remains to be fully analyzed from an academic standpoint. In this paper we show why patent sharks can operate profitably, why they are of growing concern, how manufacturers can forearm themselves against them, and which issues policy makers need to address. To do...... so, we map international indemnification rules with strategic rationales of small patent-holding firms within a game-theoretical model. Our central finding is that the courts’ unrealistic consideration of the trade-offs faced by inadvertent infringers is a central condition for sharks to operate...

  5. Active predation by Greenland shark Somniosus microcephalus

    DEFF Research Database (Denmark)

    Nielsen, Julius; hedeholm, Rasmus; Simon, Malene

    2013-01-01

    and show that the sharks catch epi-benthic species with Atlantic cod being the most important (% IRI = 56 ), followed by squid (% IRI= 13 ) and wolf fish (IRI=4). Furthermore seal was found in 50 % of all stomachs (% IRI= 13). In addition to providing new knowledge of feeding habits of this species......Dansk Havforskermøde 2013 Julius Nielsen, Rasmus Hedeholm, Malene Simon og John Fleng Steffensen The Greenland shark is ubiquitous in the northern part of the North Atlantic ranging from eastern Canada to northwest Russia . Although knowledge is scarce it is believed to be abundant and potentially...... important part of the ecosystem. Whether Greenland sharks in general should be considered opportunistic scavengers or active predators is therefore important in understanding ecosystem dynamics. Due to its sluggish appearance and a maximum reported swimming speed of 74 cm per second scavenging seems...

  6. Allometric relationships of the dentition of the great White Shark, Carcharodon carcharias, in forensic investigations of shark attacks

    OpenAIRE

    Nambiar, P.; Bridges, T. E.; Brown, K. A.

    2017-01-01

    As a result of a systematic morphometric study of shark dentitions, a system of notation for describing the location of shark teeth has been developed and is proposed as a standard to be adopted for use in similar studies in the future. The macroscopic morphology of White Shark teeth has been characterised in order to gain quantitative data which might assist in identification of these sharks from bite marks on victims or objects or from shark carcasses. Using these data, a nomogram has been ...

  7. As (V) biosorption in an aqueous solution using chemically treated lemon (Citrus aurantifolia Swingle) residues.

    Science.gov (United States)

    Marín-Rangel, Vania Marilyn; Cortés-Martínez, Raúl; Villanueva, Ruth Alfaro Cuevas; Garnica-Romo, Ma Guadalupe; Martínez-Flores, Héctor Eduardo

    2012-01-01

    The use of biosorbents to remove metals and metalloids from contaminated water systems has gained great usage in various parts of the world. The objective of the current study was to test lemon peels as biosorbents for As (V). Lemon peels were chemically characterized and arsenic contact experiments were performed to determine the adsorption capacity of the peels using different empirical models. The model that fit the experimental data was the Lagergren empirical model with a correlation coefficient of R= 0.8841. The results show that lemon peels were able to retain 474.8 μg of As (V)/g of biosorbent. Lemon agro-industrial waste can be useful in the removal of heavy metals, such as arsenic, from aqueous media. © 2011 Institute of Food Technologists®

  8. Phytostabilisation potential of lemon grass (Cymbopogon flexuosus (Nees ex Stend) Wats) on iron ore tailings.

    Science.gov (United States)

    Mohanty, M; Dhal, N K; Patra, P; Das, B; Reddy, P S R

    2012-01-01

    The present pot culture study was carried out for the potential phytostabilisation of iron ore tailings using lemon grass (Cymbopogon flexuosus) a drought tolerant, perennial, aromatic grass. Experiments have been conducted by varying the composition of garden soil (control) with iron ore tailings. The various parameters, viz. growth of plants, number of tillers, biomass and oil content of lemon grass are evaluated. The studies have indicated that growth parameters of lemon grass in 1:1 composition of garden soil and iron ore tailings are significantly more (-5% increase) compared to plants grown in control soil. However, the oil content of lemon grass in both the cases more or less remained same. The results also infer that at higher proportion of tailings the yield of biomass decreases. The studies indicate that lemongrass with its fibrous root system is proved to be an efficient soil binder by preventing soil erosion.

  9. Biological responses of sharks to ocean acidification.

    Science.gov (United States)

    Rosa, Rui; Rummer, Jodie L; Munday, Philip L

    2017-03-01

    Sharks play a key role in the structure of marine food webs, but are facing major threats due to overfishing and habitat degradation. Although sharks are also assumed to be at relatively high risk from climate change due to a low intrinsic rate of population growth and slow rates of evolution, ocean acidification (OA) has not, until recently, been considered a direct threat. New studies have been evaluating the potential effects of end-of-century elevated CO 2 levels on sharks and their relatives' early development, physiology and behaviour. Here, we review those findings and use a meta-analysis approach to quantify the overall direction and magnitude of biological responses to OA in the species of sharks that have been investigated to date. While embryo survival and development time are mostly unaffected by elevated CO 2 , there are clear effects on body condition, growth, aerobic potential and behaviour (e.g. lateralization, hunting and prey detection). Furthermore, studies to date suggest that the effects of OA could be as substantial as those due to warming in some species. A major limitation is that all past studies have involved relatively sedentary, benthic sharks that are capable of buccal ventilation-no studies have investigated pelagic sharks that depend on ram ventilation. Future research should focus on species with different life strategies (e.g. pelagic, ram ventilators), climate zones (e.g. polar regions), habitats (e.g. open ocean), and distinct phases of ontogeny in order to fully predict how OA and climate change will impact higher-order predators and therefore marine ecosystem dynamics. © 2017 The Author(s).

  10. A refreshing beverage from mature coconut water blended with lemon juice

    OpenAIRE

    Chauhan, O. P.; Archana, B. S.; Singh, Asha; Raju, P. S.; Bawa, A. S.

    2012-01-01

    Coconut water obtained from the mature coconuts was blended with lemon juice to develop a refreshing beverage. The levels of total soluble solids (°Brix) in the coconut beverage and lemon juice (%), were optimized using response surface methodology and considering pH, CIE L* value and sensory attributes (colour, aroma, taste, consistency and overall acceptability) as responses. A number total of 14 experiments were carried out following Central Composite Rotatable Design (CCRD) keeping 6 expe...

  11. The relationship between growth stages and aroma composition of lemon basil Ocimum citriodorum Vis

    OpenAIRE

    Al-Kateb, H.; DONALD, M.

    2014-01-01

    Plants produce volatiles depending on the season, growth cycle and time of year. Lemon basil “Ocmium basilicum var.citrodorum” possesses three growth stages; pre-flowering, full flowering and post-flowering. The volatiles of lemon basil infusions either increased or decreased throughout the growth cycle. Oxygenated compounds were the predominant class detected. Volatiles such as citral (neral+geranial), eucalyptol and estragole contribute to the flavor profile and may contribute in the plant ...

  12. Allometric relationships of the dentition of the great White Shark, Carcharodon carcharias, in forensic investigations of shark attacks.

    Science.gov (United States)

    Nambiar, P; Bridges, T E; Brown, K A

    1991-06-01

    As a result of a systematic morphometric study of shark dentitions, a system of notation for describing the location of shark teeth has been developed and is proposed as a standard to be adopted for use in similar studies in the future. The macroscopic morphology of White Shark teeth has been characterised in order to gain quantitative data which might assist in identification of these sharks from bite marks on victims or objects or from shark carcasses. Using these data, a nomogram has been developed which can be used to estimate the body length of a White Shark from measurements of tooth or bite mark morphology. An example of the forensic application of such allometric data is provided as it applied to a recent fatal attack on a diver by a White Shark.

  13. Fatal tiger shark, Galeocerdo cuvier attack in New Caledonia erroneously ascribed to great white shark, Carcharodon carcharias.

    Science.gov (United States)

    Tirard, Philippe; Maillaud, Claude; Borsa, Philippe

    2015-07-01

    To understand the causes and patterns of shark attacks on humans, accurate identification of the shark species involved is necessary. Often, the only reliable evidence for this comes from the characteristics of the wounds exhibited by the victim. The present case report is intended as a reappraisal of the Luengoni, 2007 case (International Shark Attack File no. 4299) where a single shark bite provoked the death of a swimmer by haemorrhagic shock. Our examination of the wounds on the body of the victim, here documented by so-far unpublished photographic evidence, determined that the shark possessed large and homodontous jaws. This demonstrates that the attacker was a tiger shark, not a great white shark as previously published. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  14. Bacteriology of the teeth from a great white shark: potential medical implications for shark bite victims.

    OpenAIRE

    Buck, J D; Spotte, S; Gadbaw, J J

    1984-01-01

    Bacteria were cultured for the first time from the teeth of a great white shark (Carcharodon carcharias). Isolates included Vibrio alginolyticus, Vibrio fluvialis, Vibrio parahaemolyticus, and other genera. All are common in the marine environment and some may be associated with wound infections in humans. Shark bite lacerations may serve as a source of these potentially infectious bacteria, particularly Vibrio spp., and should be treated immediately. Antibiotic susceptibility patterns are sh...

  15. 75 FR 9158 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery

    Science.gov (United States)

    2010-03-01

    ... Coastal Fisheries Cooperative Management Act Provisions; Coastal Sharks Fishery AGENCY: National Marine... Commission's Interstate Fishery Management Plan (ISFMP) for Coastal Sharks. Subsequently, the Commission... New Jersey failed to carry out its responsibilities under the Coastal Sharks ISFMP, and if the...

  16. Reef sharks: recent advances in ecological understanding to inform conservation.

    Science.gov (United States)

    Osgood, G J; Baum, J K

    2015-12-01

    Sharks are increasingly being recognized as important members of coral-reef communities, but their overall conservation status remains uncertain. Nine of the 29 reef-shark species are designated as data deficient in the IUCN Red List, and three-fourths of reef sharks had unknown population trends at the time of their assessment. Fortunately, reef-shark research is on the rise. This new body of research demonstrates reef sharks' high site restriction, fidelity and residency on coral reefs, their broad trophic roles connecting reef communities and their high population genetic structure, all information that should be useful for their management and conservation. Importantly, recent studies on the abundance and population trends of the three classic carcharhinid reef sharks (grey reef shark Carcharhinus amblyrhynchos, blacktip reef shark Carcharhinus melanopterus and whitetip reef shark Triaenodon obesus) may contribute to reassessments identifying them as more vulnerable than currently realized. Because over half of the research effort has focused on only these three reef sharks and the nurse shark Ginglymostoma cirratum in only a few locales, there remain large taxonomic and geographic gaps in reef-shark knowledge. As such, a large portion of reef-shark biodiversity remains uncharacterized despite needs for targeted research identified in their red list assessments. A research agenda for the future should integrate abundance, life history, trophic ecology, genetics, habitat use and movement studies, and expand the breadth of such research to understudied species and localities, in order to better understand the conservation requirements of these species and to motivate effective conservation solutions. © 2015 The Fisheries Society of the British Isles.

  17. Phylogenetic origin of limes and lemons revealed by cytoplasmic and nuclear markers.

    Science.gov (United States)

    Curk, Franck; Ollitrault, Frédérique; Garcia-Lor, Andres; Luro, François; Navarro, Luis; Ollitrault, Patrick

    2016-04-01

    The origin of limes and lemons has been a source of conflicting taxonomic opinions. Biochemical studies, numerical taxonomy and recent molecular studies suggested that cultivated Citrus species result from interspecific hybridization between four basic taxa (C. reticulata,C. maxima,C. medica and C. micrantha). However, the origin of most lemons and limes remains controversial or unknown. The aim of this study was to perform extended analyses of the diversity, genetic structure and origin of limes and lemons. The study was based on 133 Citrus accessions. It combined maternal phylogeny studies based on mitochondrial and chloroplastic markers, and nuclear structure analysis based on the evaluation of ploidy level and the use of 123 markers, including 73 basic taxa diagnostic single nucleotide polymorphism (SNP) and indel markers. The lime and lemon horticultural group appears to be highly polymorphic, with diploid, triploid and tetraploid varieties, and to result from many independent reticulation events which defined the sub-groups. Maternal phylogeny involves four cytoplasmic types out of the six encountered in the Citrus genus. All lime and lemon accessions were highly heterozygous, with interspecific admixture of two, three and even the four ancestral taxa genomes. Molecular polymorphism between varieties of the same sub-group was very low. Citrus medica contributed to all limes and lemons and was the direct male parent for the main sub-groups in combination with C. micrantha or close papeda species (for C. aurata, C. excelsa, C. macrophylla and C. aurantifolia--'Mexican' lime types of Tanaka's taxa), C. reticulata(for C. limonia, C. karna and C. jambhiri varieties of Tanaka's taxa, including popular citrus rootstocks such as 'Rangpur' lime, 'Volkamer' and 'Rough' lemons), C. aurantium (for C. limetta and C. limon--yellow lemon types--varieties of Tanaka's taxa) or the C. maxima × C. reticulate hybrid (for C. limettioides--'Palestine sweet' lime types--and C

  18. Sharks eating mosasaurs, dead or alive?

    NARCIS (Netherlands)

    Rothschild, B. M.; Martin, L. D.; Schulp, A. S.

    Shark bite marks on mosasaur bones abound in the fossil record. Here we review examples from Kansas (USA) and the Maastrichtian type area (SE Netherlands, NE Belgium), and discuss whether they represent scavenging and/or predation. Some bite marks are most likely the result of scavenging. On the

  19. Effects of Lemon Balm on the Oxidative Stability and the Quality Properties of Hamburger Patties during Refrigerated Storage

    OpenAIRE

    Lee, Hyun-Joo; Choi, You-Jung; Choi, Yang-Il; Lee, Jae-Joon

    2014-01-01

    This study was performed to investigate the effects of lemon balm (Melissa officinalis L.) on various quality and antioxidant activity of hamburger patties. Lemon balm extract (LBE) showed the highest amount of total polyphenol (801.00 mg TAE/g DW) and flavonoids (65.05 mg RA/g DW). The IC50 value of DPPH hydroxyl scavenging of LBE was 132 ?g/mL. The hamburger patties were prepared by 0% (N), 0.1% (L1), 0.5% (L2), and 1.0% (L3) of the lemon balm powder. The addition of lemon balm powder incre...

  20. New data visualization of the LHC Era Monitoring (Lemon) system

    International Nuclear Information System (INIS)

    Ivan, Fedorko; Veronique, Lefebure; Daniel, Lenkes; Omar, Pera Mira

    2012-01-01

    In the last few years, new requirements have been received for visualization of monitoring data: advanced graphics, flexibility in configuration and decoupling of the presentation layer from the monitoring repository. Lemonweb is the data visualization component of the LHC Era Monitoring (Lemon) system. Lemonweb consists of two subcomponents: a data collector and a web visualization interface. The data collector is a daemon, implemented in Python, responsible for data gathering from the central monitoring repository and storing into time series data structures. Data is stored on disk in Round Robin Database (RRD) files: one file per monitored entity, with set of entity related metrics. Entities may be grouped into a hierarchical structure, called “clusters” and supporting mathematical operations over entities and clusters (e.g. cluster A + cluster B /clusters C – entity XY). Using the configuration information, a cluster definition is evaluated in the collector engine and, at runtime, a sequence of data selects is built, to optimize access to the central monitoring repository. In this article, an overview of the design and architecture as well as highlights of some implemented features will be presented.

  1. The Greenland shark (Somniosus microcephalus)

    DEFF Research Database (Denmark)

    Nielsen, Julius

    radiocarbon dating and a Bayesian calibration model to estimate longevity of the Greenland shark. The analyzed tissue stems from the eye lens nucleus – unique material which presumably reflects age 0 of the shark, as it has not undergone metabolic changes during the animal’s life. By studying 28 Greenland...... shark females between 81 cm and 502 cm, I estimate the oldest shark to be between 272 years and 512 years. With an estimated lifespan of at least 272 years, the Greenland shark is the longest living vertebrate animal in the world. In order to produce these age estimates, it has been necessary to study...... continental shelf waters in southern Greenland at depths between 200 and 550 m and fed primarily on cod, redfish and seals. From previous investigations of predatory sharks and whales in the north Atlantic, bomb radiocarbon has been widely applied, and I argue that a similar calibration approach is valid...

  2. Sharks in Captivity: The Role of Husbandry, Breeding, Education, and Citizen Science in Shark Conservation.

    Science.gov (United States)

    Grassmann, Michael; McNeil, Bryan; Wharton, Jim

    The role of public aquariums in promoting conservation has changed substantially over the decades, evolving from entertainment attractions to educational and research centres. In many facilities, larger sharks are an essential part of the collection and represent one of the biggest draws for the public. Displaying healthy elasmobranchs comes with many challenges, but improvements in husbandry techniques have enabled aquariums to have success with a variety of species. The establishment of organisations such as the Association of Zoos and Aquariums, and the completion of texts like the Elasmobranch Husbandry Manual, has helped set high standards of care for sharks in captivity and promoted international conservation efforts. Aquariums keeping sharks are in a unique position to influence local, regional, and international attitudes and policies by acting as both educational and research facilities. Interactions with multiple stakeholders of diverse educational and demographic backgrounds through the use of in-house advocacy, public outreach, media interviews, and partnerships with academic and government institutions enable these facilities to engage and share information with a broad audience. Although the data collected on sharks in captivity often cannot be directly translated to animals in the wild, it offers better insight into a number of life history traits and poorly understood behaviours, and has been the foundation for many captive breeding programs. Several Northeast Pacific (NEP) shark species are commonly displayed for long durations or bred in aquariums, while other less studied species have been held for short periods to collect valuable data that can be applied towards ongoing studies and conservation measures. Here, we discuss past and current tangible benefits of holding NEP sharks in captivity, as well as noting several ways in which future research and education activities will continue to inform and shape public opinions on shark management and

  3. Seasonal and long-term changes in relative abundance of bull sharks from a tourist shark feeding site in Fiji.

    Science.gov (United States)

    Brunnschweiler, Juerg M; Baensch, Harald

    2011-01-27

    Shark tourism has become increasingly popular, but remains controversial because of major concerns originating from the need of tour operators to use bait or chum to reliably attract sharks. We used direct underwater sampling to document changes in bull shark Carcharhinus leucas relative abundance at the Shark Reef Marine Reserve, a shark feeding site in Fiji, and the reproductive cycle of the species in Fijian waters. Between 2003 and 2009, the total number of C. leucas counted on each day ranged from 0 to 40. Whereas the number of C. leucas counted at the feeding site increased over the years, shark numbers decreased over the course of a calendar year with fewest animals counted in November. Externally visible reproductive status information indicates that the species' seasonal departure from the feeding site may be related to reproductive activity.

  4. Field hearing measurements of the Atlantic sharpnose shark Rhizoprionodon terraenovae.

    Science.gov (United States)

    Casper, B M; Mann, D A

    2009-12-01

    Field measurements of hearing thresholds were obtained from the Atlantic sharpnose shark Rhizoprionodon terraenovae using the auditory evoked potential method (AEP). The fish had most sensitive hearing at 20 Hz, the lowest frequency tested, with decreasing sensitivity at higher frequencies. Hearing thresholds were lower than AEP thresholds previously measured for the nurse shark Ginglymostoma cirratum and yellow stingray Urobatis jamaicensis at frequencies sharks which have been observed in acoustic field attraction experiments. The sound pressure levels that would be equivalent to the particle acceleration thresholds of R. terraenovae were much higher than the sound levels which attracted closely related sharks suggesting a discrepancy between the hearing threshold experiments and the field attraction experiments.

  5. Thresher sharks use tail-slaps as a hunting strategy.

    Science.gov (United States)

    Oliver, Simon P; Turner, John R; Gann, Klemens; Silvosa, Medel; D'Urban Jackson, Tim

    2013-01-01

    The hunting strategies of pelagic thresher sharks (Alopias pelagicus) were investigated at Pescador Island in the Philippines. It has long been suspected that thresher sharks hunt with their scythe-like tails but the kinematics associated with the behaviour in the wild are poorly understood. From 61 observations recorded by handheld underwater video camera between June and October 2010, 25 thresher shark shunting events were analysed. Thresher sharks employed tail-slaps to debilitate sardines at all times of day. Hunting events comprised preparation, strike, wind-down recovery and prey item collection phases, which occurred sequentially. Preparation phases were significantly longer than the others, presumably to enable a shark to windup a tail-slap. Tail-slaps were initiated by an adduction of the pectoral fins, a manoeuvre that changed a thresher shark's pitch promoting its posterior region to lift rapidly, and stall its approach. Tail-slaps occurred with such force that they may have caused dissolved gas to diffuse out of the water column forming bubbles. Thresher sharks were able to consume more than one sardine at a time, suggesting that tail-slapping is an effective foraging strategy for hunting schooling prey. Pelagic thresher sharks appear to pursue sardines opportunistically by day and night, which may make them vulnerable to fisheries. Alopiids possess specialist pectoral and caudal fins that are likely to have evolved, at least in part, for tail-slapping. The evidence is now clear; thresher sharks really do hunt with their tails.

  6. LEMONS - A Tool for the Identification of Splice Junctions in Transcriptomes of Organisms Lacking Reference Genomes.

    Directory of Open Access Journals (Sweden)

    Liron Levin

    Full Text Available RNA-seq is becoming a preferred tool for genomics studies of model and non-model organisms. However, DNA-based analysis of organisms lacking sequenced genomes cannot rely on RNA-seq data alone to isolate most genes of interest, as DNA codes both exons and introns. With this in mind, we designed a novel tool, LEMONS, that exploits the evolutionary conservation of both exon/intron boundary positions and splice junction recognition signals to produce high throughput splice-junction predictions in the absence of a reference genome. When tested on multiple annotated vertebrate mRNA data, LEMONS accurately identified 87% (average of the splice-junctions. LEMONS was then applied to our updated Mediterranean chameleon transcriptome, which lacks a reference genome, and predicted a total of 90,820 exon-exon junctions. We experimentally verified these splice-junction predictions by amplifying and sequencing twenty randomly selected genes from chameleon DNA templates. Exons and introns were detected in 19 of 20 of the positions predicted by LEMONS. To the best of our knowledge, LEMONS is currently the only experimentally verified tool that can accurately predict splice-junctions in organisms that lack a reference genome.

  7. CATCH COMPOSITION AND SOME BIOLOGICAL ASPECTS OF SHARKS IN WESTERN SUMATERA WATERS OF INDONESIA

    Directory of Open Access Journals (Sweden)

    Dharmadi Dharmadi

    2017-01-01

    Full Text Available This study was conducted in western Sumatera and since October 2013 to June 2014. The sampling locations in Banda Aceh and Sibolga-North Sumatera which were the largest base of fisheries in western Sumatera region. Shark landing recorded by enumerators was used  as sampling data daily . This research aim to describ sex ratio, size composition, catch composition of sharks, and length at first maturity. In Banda Aceh, the sharks as target fish collected by  sorting the bycatch from tuna longlines and tuna handlines. In Sibolga, sharks  is bycatch from fish net, bottom gillnet and purse seine. Overall, there were 20 species of shark caught in west Indian Ocean and landed at those fish landing sites, dominated by Spot tail shark (23% and Silky shark (13%, whereas Hammerhead shark contributed about 10% and  Oceanic whitetip shark was only less than 1%. Almost of Spot tail shark, Silky shark, and Scalloped hammerhead that caught in that area were  immature, while for the almost part of Tiger shark and Pelagic thresher were  matured. The sex ratios for Spot tail shark, Silky shark, Tiger shark, Pelagic thresher, and Scalloped hammerhead caught and landed at Lampulo and Sibolga fish landing sites were not balance. The length at first maturity for Spot tail shark was Lm=87,1 cm and Lm = 213,2 cm total length for Tiger shark.

  8. Unprovoked fatal shark attack in Lifou Island (Loyalty Islands, New Caledonia, South Pacific) by a great white shark, Carcharodon carcharias.

    Science.gov (United States)

    Clua, Eric; Séret, Bernard

    2010-09-01

    The case of a fatal, unprovoked shark attack is reported and analyzed. The incident took place on the 30th of September 2007, in the lagoon of Luengoni Bay, Lifou Island (Loyalty Islands, New Caledonia). A young French woman who was snorkeling was severely bitten on the right thigh and died of hemorrhage. An analysis based in particular on the size and color of the shark, the characteristics of the wounds, and the behavior of the shark before and after the bite suggests that the aggressor was a great white shark, Carcharodon carcharias.

  9. Pectic oligosacharides from lemon peel wastes: production, purification, and chemical characterization.

    Science.gov (United States)

    Gómez, Belén; Gullón, Beatriz; Yáñez, Remedios; Parajó, Juan C; Alonso, Jose L

    2013-10-23

    Lemon peel wastes were extracted with water to remove free sugars and other soluble compounds, and the insoluble solid was employed as a substrate for the manufacture of pectin-derived oligosaccharides by processing with hot, compressed water. When water-extracted lemon peel wastes were treated with water at 160 °C, the oligomer concentration reached the maximum value (31 g/L). Autohydrolysis liquors were subjected to two membrane filtration stages (diafiltration followed by concentration), yielding a refined product containing about 98 wt % of oligomers at a global yield of 14 kg/100 kg oven-dry lemon peel. The concentrate contained oligogalacturonides (with DP in the range of 2-18) and arabinooligosaccharides (with DP in the range of 2-8).

  10. Effects of different pollination combinations on fruit set in some lemon varieties

    Directory of Open Access Journals (Sweden)

    Gülay DEMİR

    2015-12-01

    Full Text Available Some new lemon varieties and some standart lemon varieties were used as plant material in the planned project. The effects of selfing, crossing and reciprocal crossing methods on fruit set were investigated. The study was carried out in Batı Akdeniz Agricultural Research Institute’s fruit department station in 2011-2012 years. In the study, it was determined the effects of self-pollination, naturel open pollination and reciprocal pollination on fruit set of limon varieties (BATEM Pınarı, BATEM Sarısı, Interdonato, Kütdiken, Italyan Memeli, Meyer, Lamas. According to results, İtalyan Memeli lemon with 35.17% was determined the highest rate on account of percentage of fruits at harvest time.

  11. PENGARUH AROMATERAPI INHALASI LEMON TERHADAP PENURUNAN NYERI PERSALINAN KALA I FASE AKTIF

    Directory of Open Access Journals (Sweden)

    Siti Cholifah

    2016-07-01

    Full Text Available This research to describe the effects of lemon aromatherapy inhalation on the reduction of first stage  labor pain in the active phase. The study was a quasi-experimental with pre-test-post-test non equivalent control group design. Mann-Whitney bivariable analysis and linear regression for multivariable analysis. The result of this study was average of labor pain in aromatherapy group was  4.74 + 1.327 wich is lower  than  control group 5.79 + 1.316. Result of Mann-Whitney test is  P 0.001 < 0.05. External variables which influence the labor pain was anxiety  with  the value of P < 0.05. There is inhaled lemon aromatherapy effect on reducing first stage labor pain  in active phase. Keywords: lemon aromatherapy inhalation, labor pain, first stage, active phase

  12. Re-creating missing population baselines for Pacific reef sharks.

    Science.gov (United States)

    Nadon, Marc O; Baum, Julia K; Williams, Ivor D; McPherson, Jana M; Zgliczynski, Brian J; Richards, Benjamin L; Schroeder, Robert E; Brainard, Russell E

    2012-06-01

    Sharks and other large predators are scarce on most coral reefs, but studies of their historical ecology provide qualitative evidence that predators were once numerous in these ecosystems. Quantifying density of sharks in the absence of humans (baseline) is, however, hindered by a paucity of pertinent time-series data. Recently researchers have used underwater visual surveys, primarily of limited spatial extent or nonstandard design, to infer negative associations between reef shark abundance and human populations. We analyzed data from 1607 towed-diver surveys (>1 ha transects surveyed by observers towed behind a boat) conducted at 46 reefs in the central-western Pacific Ocean, reefs that included some of the world's most pristine coral reefs. Estimates of shark density from towed-diver surveys were substantially lower (sharks observed in towed-diver surveys and human population in models that accounted for the influence of oceanic primary productivity, sea surface temperature, reef area, and reef physical complexity. We used these models to estimate the density of sharks in the absence of humans. Densities of gray reef sharks (Carcharhinus amblyrhynchos), whitetip reef sharks (Triaenodon obesus), and the group "all reef sharks" increased substantially as human population decreased and as primary productivity and minimum sea surface temperature (or reef area, which was highly correlated with temperature) increased. Simulated baseline densities of reef sharks under the absence of humans were 1.1-2.4/ha for the main Hawaiian Islands, 1.2-2.4/ha for inhabited islands of American Samoa, and 0.9-2.1/ha for inhabited islands in the Mariana Archipelago, which suggests that density of reef sharks has declined to 3-10% of baseline levels in these areas. ©2012 Society for Conservation Biology No claim to original US government works.

  13. An investigation into ciguatoxin bioaccumulation in sharks.

    Science.gov (United States)

    Meyer, Lauren; Capper, Angela; Carter, Steve; Simpfendorfer, Colin

    2016-09-01

    Ciguatoxins (CTXs) produced by benthic Gambierdiscus dinoflagellates, readily biotransform and bioaccumulate in food chains ultimately bioconcentrating in high-order, carnivorous marine species. Certain shark species, often feeding at, or near the top of the food-chain have the ability to bioaccumulate a suite of toxins, from both anthropogenic and algal sources. As such, these apex predators are likely sinks for CTXs. This assumption, in conjunction with anecdotal knowledge of poisoning incidents, several non-specific feeding trials whereby various terrestrial animals were fed suspect fish flesh, and a single incident in Madagascar in 1994, have resulted in the widespread acceptance that sharks may accumulate CTXs. This prompted a study to investigate original claims within the literature, as well as investigate CTX bioaccumulation in the muscle and liver of 22 individual sharks from nine species, across four locations along the east coast of Australia. Utilizing an updated ciguatoxin extraction method with HPLC-MS/MS, we were unable to detect P-CTX-1, P-CTX-2 or P-CTX-3, the three primary CTX congeners, in muscle or liver samples. We propose four theories to address this finding: (1) to date, methods have been optimized for teleost species and may not be appropriate for elasmobranchs, or the CTXs may be below the limit of detection; (2) CTX may be biotransformed into elasmobranch-specific congeners as a result of unique metabolic properties; (3) 22 individuals may be an inadequate sample size given the rare occurrence of high-order ciguatoxic organisms and potential for CTX depuration; and (4) the ephemeral nature and inconsistent toxin profiles of Gambierdiscus blooms may have undermined our classifications of certain areas as CTX hotspots. These results, in combination with the lack of clarity within the literature, suggest that ciguatoxin bioaccumulation in sharks remains elusive, and warrants further investigation to determine the dynamics of toxin production

  14. 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...

  15. 75 FR 8304 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2010-02-24

    ... Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and Identification... gear, and have also been issued shark or swordfish limited access permits. Additional free workshops... Coastal Highway, Ocean City, MD 21842. Atlantic Shark Identification Workshop Since January 1, 2007, shark...

  16. 77 FR 61562 - Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2012-10-10

    .... 120706221-2481-01] RIN 0648-XC106 Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2013 fishing season for the Atlantic commercial shark... the 2011 and 2012 Atlantic commercial shark fishing seasons. We propose to keep the porbeagle shark...

  17. 78 FR 25685 - Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation Act of 2010

    Science.gov (United States)

    2013-05-02

    .... 111014628-3329-01] RIN 0648-BB54 Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation... implement the provisions of the Shark Conservation Act of 2010 (SCA) and prohibit any person from removing any of the fins of a shark at sea, possessing shark fins on board a fishing vessel unless they are...

  18. 75 FR 67251 - Atlantic Highly Migratory Species; Inseason Action To Close the Commercial Blacknose Shark and...

    Science.gov (United States)

    2010-11-02

    ...-XZ95 Atlantic Highly Migratory Species; Inseason Action To Close the Commercial Blacknose Shark and Non-Blacknose Small Coastal Shark Fisheries AGENCY: National Marine Fisheries Service (NMFS), National Oceanic...: NMFS is closing the commercial blacknose shark and non- blacknose small coastal shark (SCS) fisheries...

  19. Interacting with wildlife tourism increases activity of white sharks.

    Science.gov (United States)

    Huveneers, Charlie; Watanabe, Yuuki Y; Payne, Nicholas L; Semmens, Jayson M

    2018-01-01

    Anthropogenic activities are dramatically changing marine ecosystems. Wildlife tourism is one of the fastest growing sectors of the tourism industry and has the potential to modify the natural environment and behaviour of the species it targets. Here, we used a novel method to assess the effects of wildlife tourism on the activity of white sharks ( Carcharodon carcharias ). High frequency three-axis acceleration loggers were deployed on ten white sharks for a total of ~9 days. A combination of multivariate and univariate analysis revealed that the increased number of strong accelerations and vertical movements when sharks are interacting with cage-diving operators result in an overall dynamic body acceleration (ODBA) ~61% higher compared with other times when sharks are present in the area where cage-diving occurs. Since ODBA is considered a proxy of metabolic rate, interacting with cage-divers is probably more costly than are normal behaviours of white sharks at the Neptune Islands. However, the overall impact of cage-diving might be small if interactions with individual sharks are infrequent. This study suggests wildlife tourism changes the instantaneous activity levels of white sharks, and calls for an understanding of the frequency of shark-tourism interactions to appreciate the net impact of ecotourism on this species' fitness.

  20. Mercury content of shark from south-western Australian waters

    Energy Technology Data Exchange (ETDEWEB)

    Caputi, N.; Edmonds, J.S.; Heald, D.I.

    1979-11-01

    Muscle samples from four species of commercially sought sharks off the Western Australia coast were analyzed for total mercury. While substantial amounts of mercury were accumulated by sharks, as by other marine fish, the lack of polluting industry on the coast indicates that such mercury levels probably are natural. Mercury concentrations generally increased with fish size. (4 graphs, 1 map, 8 references, 2 tables)

  1. Supercritical fluid chromatography of fish, shark and seal oils

    DEFF Research Database (Denmark)

    Borch-Jensen, Christina; Mollerup, Jørgen

    1996-01-01

    Various natural and treated fish, shark liver and seal oils have been analyzed by supercritical fluid chromatography (SFC) using a non-polar capillary column. The lipids are separated according to molecular mass. The lipid groups found included free fatty acids, cholesterol, squalene, vitamins, wax...... applications of SFC on fish, seal and shark liver oils are presented....

  2. Cephalopods in the diets of four shark species ( galeocerdo Cuvier ...

    African Journals Online (AJOL)

    The cephalopod components of the diets of four species of shark, tiger Galeocerdo cuvier, smooth hammerhead Sphyrna zygaena, scalloped hammerhead S. lewini and great hammerhead S. mokarran, were examined to reveal patterns of prey choice. Although these sharks were caught in the inshore gillnets used in ...

  3. Record Litter Size for the Bull Shark, Carcharhinus leucas (Muller ...

    African Journals Online (AJOL)

    On the morning of 25 September 2013, a large female bull shark, Carcharhinus leucas, was landed in Port Victoria, Seychelles. It had been caught on an anchored long line set the previous evening, within 100 m of the main fishing quay. The female exhibited an unusually large girth for this heavy-set species. The shark ...

  4. Age and growth of the common blacktip shark Carcharhinus ...

    African Journals Online (AJOL)

    Age and growth estimates from length-at-age data were produced for the common blacktip shark Carcharhinus limbatus from Indonesia. Back-calculation techniques were used due to a low sample size (n = 30), which was dominated by large, mature sharks. A multi-model approach incorporating Akaike's information ...

  5. Size distributions and sex ratios of sharks caught by Oman's ...

    African Journals Online (AJOL)

    Oman's fishery resources are exploited by artisanal and industrial fisheries, but the former accounts for almost 90% of landings. Within the artisanal fishery, sharks have traditionally been harvested for their flesh, but the development of a valuable export market for shark fin has led to increased utilisation of this resource, and ...

  6. White shark and other chondrichthyan interactions with the beach ...

    African Journals Online (AJOL)

    Public perception has been that an apparent increase in the nearshore occurrence of white sharks Carcharodon carcharias in False Bay, on the south coast of South Africa, can at least be partly attributed to beach-seine (treknet) operations attracting sharks into this coastal area. To assess the merit of these concerns, ...

  7. 33 CFR 117.751 - Shark River (South Channel).

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Shark River (South Channel). 117.751 Section 117.751 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.751 Shark River (South...

  8. Shark protection plan for the Dutch Caibbean EEZ

    NARCIS (Netherlands)

    Beek, van I.J.M.; Debrot, A.O.; Walker, P.A.; Kingma, I.

    2014-01-01

    Shark populations have steeply declined worldwide due to unsustainable overexploitation and in this the Caribbean region is no exception. Since the 1990s many initiatives have been developed to protect the most threatened species. Sharks play an important ecological role in tropical marine

  9. Great white sharks: the biology of Carcharodon carcharias

    National Research Council Canada - National Science Library

    Klimley, A.P; Ainley, D.G

    1996-01-01

    ... Morphology 37 Systematics of the Lamnidae and the Origination Time of Carcharodon carcharias Inferred from the Comparative Analysis of Mitochondrial DNA Sequences Size and Skeletal Anatomy of the Giant "Megatooth" Shark Carcharodon megalodon 55 Paleoecology of Fossil White Sharks 67 4. 5. 6. 7. 8. 11. Temperature, Swimming Depth, and Movements ...

  10. Uranium extraction from ores with lemon juice I,b-uranium recovery from pregnant lemon juice liquors obtained by attacking phosphate ores and suggested flowsheet

    International Nuclear Information System (INIS)

    EL-Sayed, M.H.

    1992-01-01

    In order to recover uranium from the pregnant liquors obtained by attacking safaga phosphate and qatrani phosphatic sandstone ore materials with lemon juice, methylation for acidic fraction-salt separation has been carried out. Afterwards, separation of uranium from the associated calcium (mainly present in lemon juice liquors as citrate) has been performed by making-use of the wide difference in their water solubility. The solutions containing the separated uranium were then subjected to evaporation till dryness whereby the precipitated uranyl citrate was calcined at 500 degree C to obtain the yellow orange oxide powder (U o 3 ). On the basis of one ton ore treatment, a flowsheet for uranium recovery from the two ore materials has been suggested

  11. Uranium extraction from ores with lemon juice; II,b. uranium recovery from pregnant lemon juice liquors obtained by attacking phosphate ore and suggested flowsheet

    International Nuclear Information System (INIS)

    Hussein, E.M.

    1997-01-01

    In order to recover uranium from the pregnant liquors obtained by attacking Safaga phosphate and Qatrani phosphatic sandstone ore materials with lemon juice, methylation for acidic fraction-salt separation has been carried out. Afterwards, separation of uranium from the associated calcium (mainly present in lemon juice liquors as citrate) has been performed by making-use of the wide difference in their water solubility. The solutions containing the separated uranium were then subjected to evaporation till dryness whereby the precipitated uranyl citrate was calcined at 500 degree C to obtain the yellow orange oxide powder (UO 3 ). On the basis of one ton ore treatment, a flowsheet for uranium recovery from the two ore materials has been suggested

  12. Bristled shark skin: a microgeometry for boundary layer control?

    International Nuclear Information System (INIS)

    Lang, A W; Hidalgo, P; Westcott, M; Motta, P

    2008-01-01

    There exists evidence that some fast-swimming shark species may have the ability to bristle their scales during fast swimming. Experimental work using a water tunnel facility has been performed to investigate the flow field over and within a bristled shark skin model submerged within a boundary layer to deduce the possible boundary layer control mechanisms being used by these fast-swimming sharks. Fluorescent dye flow visualization provides evidence of the formation of embedded cavity vortices within the scales. Digital particle image velocimetry (DPIV) data, used to evaluate the cavity vortex formation and boundary layer characteristics close to the surface, indicate increased momentum in the slip layer forming above the scales. This increase in flow velocity close to the shark's skin is indicative of boundary layer control mechanisms leading to separation control and possibly transition delay for the bristled shark skin microgeometry

  13. Bristled shark skin: a microgeometry for boundary layer control?

    Energy Technology Data Exchange (ETDEWEB)

    Lang, A W; Hidalgo, P; Westcott, M [Aerospace Engineering and Mechanics Department, University of Alabama, Box 870280, Tuscaloosa, AL 35487 (United States); Motta, P [Biology Department, University of South Florida, 4202 East Fowler Avenue, Tampa, FL 33620 (United States)], E-mail: alang@eng.ua.edu

    2008-12-01

    There exists evidence that some fast-swimming shark species may have the ability to bristle their scales during fast swimming. Experimental work using a water tunnel facility has been performed to investigate the flow field over and within a bristled shark skin model submerged within a boundary layer to deduce the possible boundary layer control mechanisms being used by these fast-swimming sharks. Fluorescent dye flow visualization provides evidence of the formation of embedded cavity vortices within the scales. Digital particle image velocimetry (DPIV) data, used to evaluate the cavity vortex formation and boundary layer characteristics close to the surface, indicate increased momentum in the slip layer forming above the scales. This increase in flow velocity close to the shark's skin is indicative of boundary layer control mechanisms leading to separation control and possibly transition delay for the bristled shark skin microgeometry.

  14. "Sharks in Your Hands"--A Case Study on Effects of Teaching Strategies to Change Knowledge and Attitudes towards Sharks

    Science.gov (United States)

    Lee, Hung-Shan; Liu, Shiang-Yao; Yeh, Ting-Kuang

    2016-01-01

    This study was designed to exemplify how hands-on based teaching strategies enhanced students' knowledge and positive attitudes towards sharks. Hands-on activities for sharks' biological and morphological features were carried out. Eleven elementary school students from a remote area in Taiwan were recruited and assigned to the hands-on condition.…

  15. 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.

  16. How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour.

    Science.gov (United States)

    Kempster, Ryan M; Egeberg, Channing A; Hart, Nathan S; Ryan, Laura; Chapuis, Lucille; Kerr, Caroline C; Schmidt, Carl; Huveneers, Charlie; Gennari, Enrico; Yopak, Kara E; Meeuwig, Jessica J; Collin, Shaun P

    2016-01-01

    Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scientific studies. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with recommendations of their effectiveness. Using a modified stereo-camera system, we quantified behavioural interactions between white sharks (Carcharodon carcharias) and a baited target in the presence of a commercially available, personal electric shark deterrent (Shark Shield Freedom7™). The stereo-camera system enabled an accurate assessment of the behavioural responses of C. carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error) proximity of 131 (± 10.3) cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9) V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5) V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial when in the presence of an active Shark Shield™. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C. carcharias, and an accurate method for testing

  17. How Close is too Close? The Effect of a Non-Lethal Electric Shark Deterrent on White Shark Behaviour.

    Directory of Open Access Journals (Sweden)

    Ryan M Kempster

    Full Text Available Sharks play a vital role in the health of marine ecosystems, but the potential threat that sharks pose to humans is a reminder of our vulnerability when entering the ocean. Personal shark deterrents are being marketed as the solution to mitigate the threat that sharks pose. However, the effectiveness claims of many personal deterrents are based on our knowledge of shark sensory biology rather than robust testing of the devices themselves, as most have not been subjected to independent scientific studies. Therefore, there is a clear need for thorough testing of commercially available shark deterrents to provide the public with recommendations of their effectiveness. Using a modified stereo-camera system, we quantified behavioural interactions between white sharks (Carcharodon carcharias and a baited target in the presence of a commercially available, personal electric shark deterrent (Shark Shield Freedom7™. The stereo-camera system enabled an accurate assessment of the behavioural responses of C. carcharias when encountering a non-lethal electric field many times stronger than what they would naturally experience. Upon their first observed encounter, all C. carcharias were repelled at a mean (± std. error proximity of 131 (± 10.3 cm, which corresponded to a mean voltage gradient of 9.7 (± 0.9 V/m. With each subsequent encounter, their proximity decreased by an average of 11.6 cm, which corresponded to an increase in tolerance to the electric field by an average of 2.6 (± 0.5 V/m per encounter. Despite the increase in tolerance, sharks continued to be deterred from interacting for the duration of each trial when in the presence of an active Shark Shield™. Furthermore, the findings provide no support to the theory that electric deterrents attract sharks. The results of this study provide quantitative evidence of the effectiveness of a non-lethal electric shark deterrent, its influence on the behaviour of C. carcharias, and an accurate

  18. Home range and food habits of Pacific reef sharks (primarily the gray reef shark, Carcharhinus amblyrhynchos)

    International Nuclear Information System (INIS)

    Nelson, D.R.; McKibben, J.N.; Tricas, T.C.; Cooksey, D.J.

    1979-01-01

    Progress is reported on the following studies: determining home range dimensions and stabilities by tracking sharks equipped with ultrasonic transmitters; telemetry instrumentation and techniques for applicability under Enewetak conditions; studies on social behavior, especially aggression toward divers, in relation to space utilization and group organization; and compilation of food-habit data from examination of stomach contents

  19. A recent shark radiation: molecular phylogeny, biogeography and speciation of wobbegong sharks (family: Orectolobidae).

    Science.gov (United States)

    Corrigan, Shannon; Beheregaray, Luciano B

    2009-07-01

    The elasmobranch fish are an ancient, evolutionarily successful, but under-researched vertebrate group, particularly in regard to their recent evolutionary history. Their lineage has survived four mass extinction events and most present day taxa are thought to be derived from Mesozoic forms. Here we present a molecular phylogenetic analysis of the family Orectolobidae that provides evidence for recent events of diversification in this shark group. Species interrelationships in Orectolobidae were reconstructed based on four mitochondrial and nuclear genes. In line with previous morphological work, our results do not support current taxonomic arrangements in Orectolobidae and indicate that a taxonomic revision of the family is warranted. We propose that the onset of diversification of orectolobid sharks is of Miocene age and occurred within the Indo-Australian region. Surprisingly, we also find evidence for a recent ( approximately last 2 million years) and rapid radiation of wobbegong sharks. Allopatric speciation followed by range expansion seems like the general most likely explanation to account for wobbegong relationships and distributions. We suggest that the evolution of this shark group was mostly influenced by two temporal scenarios of diversification. The oldest relates to major geological changes in the Indo-West Pacific associated with the Miocene collision of the Indo-Australian and Eurasian plates. The most recent scenario was influenced by changes in oceanography and the emergence of biogeographic barriers related to Pleistocene glacial cycles in Australian waters.

  20. No rainbow for grey bamboo sharks: evidence for the absence of colour vision in sharks from behavioural discrimination experiments.

    Science.gov (United States)

    Schluessel, V; Rick, I P; Plischke, K

    2014-11-01

    Despite convincing data collected by microspectrophotometry and molecular biology, rendering sharks colourblind cone monochromats, the question of whether sharks can perceive colour had not been finally resolved in the absence of any behavioural experiments compensating for the confounding factor of brightness. The present study tested the ability of juvenile grey bamboo sharks to perceive colour in an experimental design based on a paradigm established by Karl von Frisch using colours in combination with grey distractor stimuli of equal brightness. Results showed that contrasts but no colours could be discriminated. Blue and yellow stimuli were not distinguished from a grey distractor stimulus of equal brightness but could be distinguished from distractor stimuli of varying brightness. In addition, different grey stimuli were distinguished significantly above chance level from one another. In conclusion, the behavioural results support the previously collected physiological data on bamboo sharks, which mutually show that the grey bamboo shark, like several marine mammals, is a cone monochromate and colourblind.

  1. Increased and altered fragrance of tobacco plants after metabolic engineering using three monoterpene synthases from lemon

    NARCIS (Netherlands)

    Lücker, J.; Schwab, W.; Hautum, van B.; Blaas, J.; Plas, van der L.H.W.; Bouwmeester, H.J.; Verhoeven, H.A.

    2004-01-01

    Wild-type tobacco (Nicotiana tabacum) plants emit low levels of terpenoids, particularly from the flowers. By genetic modification of tobacco cv Petit Havana SR1 using three different monoterpene synthases from lemon (Citrus limon L. Burm. f.) and the subsequent combination of these three into one

  2. Chemical guide parameters for Spanish lemon (Citrus limon (L.) Burm.) juices.

    Science.gov (United States)

    Lorente, José; Vegara, Salud; Martí, Nuria; Ibarz, Albert; Coll, Luís; Hernández, Julio; Valero, Manuel; Saura, Domingo

    2014-11-01

    To contribute for setting reference guideline for commercial juice extracted from the Spanish lemon varieties, chemical composition of 92 direct and 92 reconstituted samples were investigated. In direct lemon juice, titratable acidity was 52.4 g/L, being the citric acid the main component. Glucose, fructose and sucrose concentrations were 7.9, 7.3 and 4.5 g/L, respectively. Predominant mineral was potassium (1264.2mg/L), followed by phosphorous (306 mg/L), calcium (112 mg/L) and magnesium (92.6 mg/L). Hesperidin ranged from 257 to 484.8 mg/L, while water soluble pectins varied between 164.8 and 550 mg/L. Similar values were obtained in reconstituted lemon juice. There are different parameters that did not reach or exceeded the limits proposed by the European Association of the Industry of Juices and Nectars. These levels should be taken into account to modify the present reference guideline and that Spanish lemon juices are not discarded for to have lower or bigger values. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Lake Garda lemon houses (Italy: Opportunities of a sensitive, marginal area in urban planning

    Directory of Open Access Journals (Sweden)

    Badiani Barbara

    2017-12-01

    Full Text Available The lemon houses of Lake Garda provide Ecosystem Services, due to their history and their deep rooting in the landscape. Unfortunately, Urban Planning hasn’t ever taken into account these possible benefits. In fact, it has always allowed their reuse as residences and it has sustained the conservation of the buildings only. The lack of interest in reintroducing lemon growing or other agricultural activities has produced a noticeable impoverishment of the local landscape. To overcome these limits, Urban Planning should be oriented to implement practices, which take root in and bring out the variety of local landscapes. In order to reach this result, Urban Planning may help to bring some lemon houses, especially the abandoned or the most vulnerable ones, back to their original agricultural vocation, reintroducing autopoietic agricultural techniques, which are in balance with the environment. An interdisciplinary approach may be adopted in a profitable way, to strengthen the efficiency of the Urban Planning. Aiming at this interdisciplinary approach the paper reports our first investigations concerning the contribution of different disciplines, which will help Urban Planning to consider, in case of the reuse of Lake Garda lemon houses, immaterial benefits and to reintroduce activities linked to their original vocation.

  4. Effect of marinating chicken meat with lemon, green tea, and turmeric against foodborne bacterial pathogenss

    Science.gov (United States)

    Foodborne diseases affect millions of people each year. To reduce the incidence of bacterial foodborne pathogens more effective treatment methods are needed. In this study we evaluated the effect of marinating chicken breast fillets with extracts of lemon, green tea, and turmeric against Campylob...

  5. Assessment of Mesophilic Co-Digestion of Cow Dung with Lemon ...

    African Journals Online (AJOL)

    The scarcity of energy (fossil) and its attendant pollution menace have provided the avenue to consider alternative sources of energy. A study was carried out on the design and construction of an Anaerobic Digester system using 1mm galvanized steel for the production of biogas from co-digestion of Cow dung and Lemon ...

  6. Biosynthesis of silver nanoparticles using lemon leaves extract and its application for antimicrobial finish on fabric

    Science.gov (United States)

    Vankar, Padma S.; Shukla, Dhara

    2012-06-01

    Preparation of silver nanoparticles have been carried out using aqueous extract of lemon leaves ( Citrus limon) which acts as reducing agent and encapsulating cage for the silver nanoparticles. These silver nanoparticles have been used for durable textile finish on cotton and silk fabrics. Remarkable antifungal activity has been observed in the treated fabrics. The antimicrobial activity of silver nanoparticles derived from lemon leaves showed enhancement in activity due to synergistic effect of silver and essential oil components of lemon leaves. The present investigation shows the extracellular synthesis of highly stable silver nanoparticles by biotransformation using the extract of lemon leaves by controlled reduction of the Ag+ ion to Ag0. Further the silver nanoparticles were used for antifungal treatment of fabrics which was tested by antifungal activity assessment of textile material by Agar diffusion method against Fusarium oxysporum and Alternaria brassicicola. Formation of the metallic nanoparticles was established by FT-IR, UV-Visible spectroscopy, transmission electron microscopy, scanning electron microscopy, atomic force microscopy.

  7. In vitro plant regeneration in rough lemon (Citrus jambhiri Lush) by ...

    African Journals Online (AJOL)

    Jane

    2011-10-17

    Oct 17, 2011 ... H S Rattanpal*1, Gagandeep Kaur2 and Monika Gupta2 ... Seeds were extracted from ripe fruits of rough lemon. ... extract and additional dose of 25 g/l sucrose. ..... important grapefruit cultivar Rio Red (Citrus paradise Macf.).

  8. Level of heavy metals in soils and lemon grass in Jos, Bukuru and ...

    African Journals Online (AJOL)

    Level of heavy metals in soils and lemon grass in Jos, Bukuru and environs, Nigeria. SJ Salami, EA Akande, DM Zachariah. Abstract. No Abstract. Global Journal of Pure and Applied Sciences Vol. 13 (2) 2007: pp. 193-196. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT ...

  9. Lemon : An MPI parallel I/O library for data encapsulation using LIME

    NARCIS (Netherlands)

    Deuzeman, Albert; Reker, Siebren; Urbach, Carsten

    We introduce Lemon, an MPI parallel I/O library that provides efficient parallel I/O of both binary and metadata on massively parallel architectures. Motivated by the demands of the lattice Quantum Chromodynamics community, the data is stored in the SciDAC Lattice QCD Interchange Message

  10. Prebiotic potential of pectins and pectic oligosaccharides derived from lemon peel wastes and sugar beet pulp

    NARCIS (Netherlands)

    Gómez, Belén; Gullón, Beatriz; Yáñez, Remedios; Schols, Henk; Alonso, José L.

    2016-01-01

    Sugar beet pulp (SBP) and lemon peel wastes (LPW) were used to obtain two mixtures of pectic oligosaccharides (denoted as SBPOS and LPOS, respectively). Oligogalacturonides in LPOS showed a larger molecular weight, higher degree of methylation and lower degree of acetylation than the ones in

  11. Immunoglobulin heavy chain exclusion in the shark.

    Directory of Open Access Journals (Sweden)

    Karolina Malecek

    2008-06-01

    Full Text Available The adaptive immune system depends on specific antigen receptors, immunoglobulins (Ig in B lymphocytes and T cell receptors (TCR in T lymphocytes. Adaptive responses to immune challenge are based on the expression of a single species of antigen receptor per cell; and in B cells, this is mediated in part by allelic exclusion at the Ig heavy (H chain locus. How allelic exclusion is regulated is unclear; we considered that sharks, the oldest vertebrates possessing the Ig/TCR-based immune system, would yield insights not previously approachable and reveal the primordial basis of the regulation of allelic exclusion. Sharks have an IgH locus organization consisting of 15-200 independently rearranging miniloci (VH-D1-D2-JH-Cmu, a gene organization that is considered ancestral to the tetrapod and bony fish IgH locus. We found that rearrangement takes place only within a minilocus, and the recombining gene segments are assembled simultaneously and randomly. Only one or few H chain genes were fully rearranged in each shark B cell, whereas the other loci retained their germline configuration. In contrast, most IgH were partially rearranged in every thymocyte (developing T cell examined, but no IgH transcripts were detected. The distinction between B and T cells in their IgH configurations and transcription reveals a heretofore unsuspected chromatin state permissive for rearrangement in precursor lymphocytes, and suggests that controlled limitation of B cell lineage-specific factors mediate regulated rearrangement and allelic exclusion. This regulation may be shared by higher vertebrates in which additional mechanistic and regulatory elements have evolved with their structurally complex IgH locus.

  12. SHARK LONGLINE FISHERY IN TANJUNGLUAR-EAST LOMBOK

    Directory of Open Access Journals (Sweden)

    Dharmadi Dharmadi

    2013-06-01

    longline fishing was conducted every month. The trend of shark catches relates to the number of fishing vessels, fishing ground, and weather conditions at sea. The period between July and September is a transitional season from East to West seasons. During this season, the wind strength is weakened and a good fishing season for the fishers. The lowest catch occurs in January (1.06 tonnes and the highest catch in September with the total catch of 24.6 tonnes. Sharks caught by surface longline were dominated by Silky shark, Carcharhinus falciformis (40-90% with the size range of 100-125 cm. The catch of bottom longline was mostly consisting of fish in mature condition that dominated by Grey reef shark (Carcharhinus amblyrhynchos, Common black tip shark (C. limbatus, Spot tail shark (C. sorrah, and Scalloped hammerhead shark (Sphyrna lewini, with the size range of 125-200 cm, 170- 250 cm, 100-150 cm, and 170-300 cm, respectively. Surface longline fishing occurs in the offshore waters in depth more than 200 m to 3000 m, whereas bottom longline fishing is operated at a depth of 50-100 m around islands.

  13. Taxonomy Icon Data: white shark [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available white shark Carcharodon carcharias Chordata/Vertebrata/Pisciformes Carcharodon_carcharias_L.png Carcharo...don_carcharias_NL.png Carcharodon_carcharias_S.png Carcharodon_carcharias_NS.png http:/.../biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Carcharodon+carcharias&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Carcharo...don+carcharias&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Carcharo...don+carcharias&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Carcharodon+carcharias&t=NS ...

  14. Movement patterns of silvertip sharks ( Carcharhinus albimarginatus) on coral reefs

    Science.gov (United States)

    Espinoza, Mario; Heupel, Michelle. R.; Tobin, Andrew J.; Simpfendorfer, Colin A.

    2015-09-01

    Understanding how sharks use coral reefs is essential for assessing risk of exposure to fisheries, habitat loss, and climate change. Despite a wide Indo-Pacific distribution, little is known about the spatial ecology of silvertip sharks ( Carcharhinus albimarginatus), compromising the ability to effectively manage their populations. We examined the residency and movements of silvertip sharks in the central Great Barrier Reef (GBR). An array of 56 VR2W acoustic receivers was used to monitor shark movements on 17 semi-isolated reefs. Twenty-seven individuals tagged with acoustic transmitters were monitored from 70 to 731 d. Residency index to the study site ranged from 0.05 to 0.97, with a mean residency (±SD) of 0.57 ± 0.26, but most individuals were detected at or near their tagging reef. Clear seasonal patterns were apparent, with fewer individuals detected between September and February. A large proportion of the tagged population (>71 %) moved regularly between reefs. Silvertip sharks were detected less during daytime and exhibited a strong diel pattern in depth use, which may be a strategy for optimizing energetic budgets and foraging opportunities. This study provides the first detailed examination of the spatial ecology and behavior of silvertip sharks on coral reefs. Silvertip sharks remained resident at coral reef habitats over long periods, but our results also suggest this species may have more complex movement patterns and use larger areas of the GBR than common reef shark species. Our findings highlight the need to further understand the movement ecology of silvertip sharks at different spatial and temporal scales, which is critical for developing effective management approaches.

  15. Dramatic increase in sea otter mortality from white sharks in California

    Science.gov (United States)

    Tinker, M. Tim; Hatfield, Brian B.; Harris, Michael D.; Ames, Jack A.

    2016-01-01

    Although southern sea otters (Enhydra lutris nereis) are not considered prey for white sharks (Carcharodon carcharias), sharks do nonetheless bite sea otters. We analyzed spatial and temporal trends in shark bites on sea otters in California, assessing the frequency of shark bite wounds in 1,870 carcasses collected since 1985. The proportion of stranded sea otters having shark bites has increased sharply since 2003, and white shark bites now account for >50% of recovered carcasses. The trend was most pronounced in the southern part of the range, from Estero Bay to Point Conception, where shark bite frequency has increased eightfold. Seasonal trends were also evident: most shark-bitten carcasses are recovered in late summer and fall; however, the period of elevated shark bite frequency has lengthened. The causes of these trends are unclear, but possible contributing factors include increased white shark abundance and/or changes in white shark behavior and distribution. In particular, the spatiotemporal patterns of shark-bitten sea otters match increases in pinniped populations, and the increased availability of marine mammal prey for white sharks may have led to more sharks spending more time in nearshore waters utilized by both sea otters and pinnipeds.

  16. Mercury in shark in western Australia: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, D.A.; Edmonds, J.S.; Edinger, J.J.

    1977-01-01

    Linear and curvilinear regressions relating mercury concentration and size were used in conjunction with catch data to estimate the average concentration in the three major shark species in the Western Australia fishery industry. The three species were whiskery (Furgaleus ventralis), bronze whaler (Carcharhinus obscurus) and gummy (Emissola antarctica) sharks. The averge mercury concentration for the 3 species was found to be approximately 0.75 ppM. The relevance of this to Public Health regulations was discussed and the need for information on consumption of shark stressed.

  17. 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

  18. Community structure of elasmobranchs in estuaries along the northwest Gulf of Mexico

    Science.gov (United States)

    Plumlee, Jeffrey D.; Dance, Kaylan M.; Matich, Philip; Mohan, John A.; Richards, Travis M.; TinHan, Thomas C.; Fisher, Mark R.; Wells, R. J. David

    2018-05-01

    Estuaries promote high levels of productivity and biodiversity by providing habitat for many biological communities due to their wide range of environmental conditions. Estuarine systems serve as nurseries, areas for parturition, and feeding grounds for elasmobranchs. However, estuaries face an array of anthropogenic pressures, including overfishing, altered flow regimes, pollution, and habitat destruction. Given the vulnerability of estuarine ecosystems, observing long-term changes in community structure is essential to understanding the effects of anthropogenic stressors. Elasmobranch community structure was analyzed among eight estuaries in the northwest Gulf of Mexico to evaluate spatial and temporal variability in species abundance and diversity using bi-annual fisheries independent gillnet survey data over three decades (1985-2014). Ten species comprised 99.4% of elasmobranchs caught which included 35.3% bull sharks (Carcharhinus leucas), 18.1% bonnetheads (Sphyrna tiburo), 17.0% cownose rays (Rhinoptera bonasus), 13.4% blacktip sharks (Carcharhinus limbatus), 5.9% Atlantic stingrays (Dasyatis sabina), 3.1% Atlantic sharpnose sharks (Rhizoprionodon terraenovae), 2.7% spinner sharks (Carcharhinus brevipinna), 2.1% scalloped hammerheads (Sphyrna lewini), 1.7% finetooth sharks (Carcharhinus isodon), and 0.7% lemon sharks (Negaprion brevirostris). During the study period, elasmobranch community structure changed among estuaries and among decades. Bull sharks, bonnetheads, cownose rays, blacktip sharks, and spinner sharks all increased in abundance during the study period, whereas finetooth sharks and lemon sharks decreased over time. Higher latitude estuaries were dominated by bull sharks while lower latitude estuaries were dominated by cownose rays. Salinity was the most important environmental variable in predicting individual elasmobranch species abundance (deviance explained: 14.4 ± 6.5 SD), while temperature and depth also played a role in shaping community

  19. A "Shark Encounter": Delayed Primary Closure and Prophylactic Antibiotic Treatment of a Great White Shark Bite.

    Science.gov (United States)

    Popa, Daniel; Van Hoesen, Karen

    2016-11-01

    Shark bites are rare but sensational injuries that are covered in the lay press but are not well described in the medical literature. We present the case of a 50-year-old man who sustained two deep puncture wounds to his thigh from a great white shark in the waters surrounding Isla de Guadalupe off the coast of Baja California, Mexico, during a caged SCUBA dive. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: We discuss our strategy of closing the wounds in a delayed primary fashion 24 hours after injury, our antibiotic choices, and the patient's course and review marine pathogens and appropriate antibiotic coverage. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. The Effect of Lemon Inhalation Aromatherapy on Nausea and Vomiting of Pregnancy: A Double-Blinded, Randomized, Controlled Clinical Trial

    OpenAIRE

    Yavari kia, Parisa; Safajou, Farzaneh; Shahnazi, Mahnaz; Nazemiyeh, Hossein

    2014-01-01

    Background: Nausea and vomiting of pregnancy are amongst the most common complaints that effects on both the physical and mental conditions of the pregnant women. Due to the increasing tendency of women to use herbal medications during pregnancy, the effect of lemon inhalation aromatherapy on nausea and vomiting of pregnancy was investigated in this study. Objectives: The aim of this study was to determine the effect of lemon inhalation aromatherapy on nausea and vomiting during pregnancy. Ma...

  1. Review of the Freshwater Sharks of Iran (Family Carcharhinidae)

    OpenAIRE

    Brian W. Coad

    2015-01-01

    The systematics, morphology, distribution, biology, economic importance and conservation of the bull shark (Carcharhinus leucas) in Iran are described, the species is illustrated, and a bibliography on this fish in Iran is provided.

  2. Determination of methylmercury and inorganic mercury in shark fillets

    NARCIS (Netherlands)

    Krystek, Petra; Ritsema, Rob

    2004-01-01

    Three samples of deep-frozen shark fillets were analysed according to the following procedure: dissolution in tetramethylammonium hydroxide, derivatization/ethylation with sodium tetraethylborate, extraction into iso-octane and measurement with gas chromatography hyphenated to inductively coupled

  3. Atlantic Sharpnose and Blacknose Shark Congressional Supplemental Sampling

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Life history data were collected from Atlantic sharpnose and blacknose sharks during the Congressional Supplemental Program during 2011. Data collected include...

  4. Review of the Freshwater Sharks of Iran (Family Carcharhinidae

    Directory of Open Access Journals (Sweden)

    Brian W. Coad

    2015-07-01

    Full Text Available The systematics, morphology, distribution, biology, economic importance and conservation of the bull shark (Carcharhinus leucas in Iran are described, the species is illustrated, and a bibliography on this fish in Iran is provided.

  5. Diet of bonnethead shark in eastern Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To examine variation in diet and daily ration of the bonnethead, Sphyrna tiburo (Linnaeus, 1758), sharks were collected from three areas in the eastern Gulf of...

  6. Shark Attack Project - Marine Attack at Towed Hydrophone Arrays

    National Research Council Canada - National Science Library

    Kalmijn, Adrianus J

    2005-01-01

    The original objective of the SIO Marine Attack project was to identify the electric and magnetic fields causing sharks to inflict serious damage upon the towed hydrophone arrays of US Navy submarines...

  7. Predator Gut Isotopes - Characterizing ecosystem role of sharks

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This work uses white muscle tissues collected from sixgill and sevengill sharks to characterize the diet of each species. Tissues from prey species have also been...

  8. Cartilage (Bovine and Shark) (PDQ®)—Health Professional Version

    Science.gov (United States)

    Expert-reviewed information summary about the use of bovine and shark cartilage as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  9. Cooperative Atlantic States Shark Pupping and Nursery (COASTSPAN)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Survey of inshore areas used by sharks for pupping and nurseries. Various locations have been surveyed, from the U.S. Virgin Islands to Massachusetts, most in...

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

    Science.gov (United States)

    Wilga, C D

    2005-07-01

    The morphology of the jaw suspension and jaw protrusion mechanism in lamniform sharks is described and mapped onto a cladogram to investigate how changes in jaw suspension and protrusion have evolved. This has revealed that several evolutionary modifications in the musculoskeletal apparatus of the jaws have taken place among lamniform sharks. Galeomorph sharks (Carcharhiniformes, Lamniformes, Orectolobiformes, and Heterodontiformes) have paired ethmopalatine ligaments connecting the ethmoid process of the upper jaw to the ethmoid region of the cranium. Basal lamniform sharks also acquired a novel single palatonasal ligament connecting the symphysis of the upper jaw to the cranium mid-ventral to the nasal capsule. Sharks in the family Lamnidae subsequently lost the original paired ethmopalatine ligament while retaining the novel palatonasal ligament. Thus, basal lamniform taxa (Mitsukurina owstoni, Carcharius taurus, Alopias vulpinnis) have increased ligamentous support of the lateral region of the upper jaw while derived species (Lamnidae) have lost this lateral support but gained anterior support. In previous studies the morphology of the jaw suspension has been shown to play a major role in the mechanism of upper jaw protrusion in elasmobranchs. The preorbitalis is the primary muscle effecting upper jaw protrusion in squalean (sister group to galeomorphs) and carcharhiniform (sister group to lamniforms) sharks. The preorbitalis originates from the quadratomandibularis muscle and inserts onto the nasal capsule in squalean and carcharhiniform sharks. Carcharhiniform sharks have evolved a subdivided preorbitalis muscle with the new division inserting near the ethmoid process of the palatoquadrate (upper jaw). Alopid sharks have also independently evolved a partially subdivided preorbitalis with the new division inserting at the base of the ethmoid process and surrounding connective tissue. Lamnid sharks have retained the two preorbitalis divisions but have modified

  11. Diet of scalloped hammerhead shark in eastern Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile scalloped hammerhead sharks, Sphyrna lewini, were collected in northwest Florida to examine foraging ecology, bioenergetics, and trophic level (30-60 cm FL...

  12. Partitioning of body fluids in the Lake Nicaragua shark and three marine sharks.

    Science.gov (United States)

    THORSON, T B

    1962-11-09

    The relative volumes of major body fluids of freshwater and marine sharks are remarkably similar in spite of the differences in external medium and in osmotic pressure of body fluids. The small differences detected are in agreement with differences reported in comparisons of freshwater and marine teleosts: a slightly higher total water content and a smiller ratio of extracellular to intracellular fluids in freshwater forms.

  13. Shark immunity bites back: affinity maturation and memory response in the nurse shark, Ginglymostoma cirratum.

    Science.gov (United States)

    Dooley, Helen; Flajnik, Martin F

    2005-03-01

    The cartilaginous fish are the oldest phylogenetic group in which all of the molecular components of the adaptive immune system have been found. Although early studies clearly showed that sharks could produce an IgM-based response following immunization, evidence for memory, affinity maturation and roles for the other isotypes (notably IgNAR) in this group remained inconclusive. The data presented here illustrate that the nurse shark (Ginglymostoma cirratum) is able to produce not only an IgM response, but we also show for the first time a highly antigen-specific IgNAR response. Additionally, under appropriate conditions, a memory response for both isotypes can be elicited. Analysis of the response shows differential expression of pentameric and monomeric IgM. Pentameric IgM provides the 'first line of defense' through high-avidity, low-affinity interaction with antigen. In contrast, monomeric IgM and IgNAR seem responsible for the specific, antigen-driven response. We propose the presence of distinct lineages of B cells in sharks. As there is no conventional isotype switching, each lineage seems pre-determined to express a single isotype (IgM versus IgNAR). However, our data suggest that there may also be specific lineages for the different forms (pentameric versus monomeric) of the IgM isotype.

  14. Predicting occurrence of juvenile shark habitat to improve conservation planning.

    Science.gov (United States)

    Oh, Beverly Z L; Sequeira, Ana M M; Meekan, Mark G; Ruppert, Jonathan L W; Meeuwig, Jessica J

    2017-06-01

    Fishing and habitat degradation have increased the extinction risk of sharks, and conservation strategies recognize that survival of juveniles is critical for the effective management of shark populations. Despite the rapid expansion of marine protected areas (MPAs) globally, the paucity of shark-monitoring data on large scales (100s-1000s km) means that the effectiveness of MPAs in halting shark declines remains unclear. Using data collected by baited remote underwater video systems (BRUVS) in northwestern Australia, we developed generalized linear models to elucidate the ecological drivers of habitat suitability for juvenile sharks. We assessed occurrence patterns at the order and species levels. We included all juvenile sharks sampled and the 3 most abundant species sampled separately (grey reef [Carcharhinus amblyrhynchos], sandbar [Carcharhinus plumbeus], and whitetip reef sharks [Triaenodon obesus]). We predicted the occurrence of juvenile sharks across 490,515 km 2 of coastal waters and quantified the representation of highly suitable habitats within MPAs. Our species-level models had higher accuracy (ĸ ≥ 0.69) and deviance explained (≥48%) than our order-level model (ĸ = 0.36 and deviance explained of 10%). Maps of predicted occurrence revealed different species-specific patterns of highly suitable habitat. These differences likely reflect different physiological or resource requirements between individual species and validate concerns over the utility of conservation targets based on aggregate species groups as opposed to a species-focused approach. Highly suitable habitats were poorly represented in MPAs with the most restrictions on extractive activities. This spatial mismatch possibly indicates a lack of explicit conservation targets and information on species distribution during the planning process. Non-extractive BRUVS provided a useful platform for building the suitability models across large scales to assist conservation planning across

  15. Movements of Blue Sharks (Prionace glauca) across Their Life History

    Science.gov (United States)

    Vandeperre, Frederic; Aires-da-Silva, Alexandre; Fontes, Jorge; Santos, Marco; Serrão Santos, Ricardo; Afonso, Pedro

    2014-01-01

    Spatial structuring and segregation by sex and size is considered to be an intrinsic attribute of shark populations. These spatial patterns remain poorly understood, particularly for oceanic species such as blue shark (Prionace glauca), despite its importance for the management and conservation of this highly migratory species. This study presents the results of a long-term electronic tagging experiment to investigate the migratory patterns of blue shark, to elucidate how these patterns change across its life history and to assess the existence of a nursery area in the central North Atlantic. Blue sharks belonging to different life stages (n = 34) were tracked for periods up to 952 days during which they moved extensively (up to an estimated 28.139 km), occupying large parts of the oceanic basin. Notwithstanding a large individual variability, there were pronounced differences in movements and space use across the species' life history. The study provides strong evidence for the existence of a discrete central North Atlantic nursery, where juveniles can reside for up to at least 2 years. In contrast with previously described nurseries of coastal and semi-pelagic sharks, this oceanic nursery is comparatively vast and open suggesting that shelter from predators is not its main function. Subsequently, male and female blue sharks spatially segregate. Females engage in seasonal latitudinal migrations until approaching maturity, when they undergo an ontogenic habitat shift towards tropical latitudes. In contrast, juvenile males generally expanded their range southward and apparently displayed a higher degree of behavioural polymorphism. These results provide important insights into the spatial ecology of pelagic sharks, with implications for the sustainable management of this heavily exploited shark, especially in the central North Atlantic where the presence of a nursery and the seasonal overlap and alternation of different life stages coincides with a high fishing

  16. Determination of physical characteristics, chemical composition and digestion coefficients of treated lemon pulp with Saccharomyces cerevisiae in goat diet.

    Science.gov (United States)

    Dadvar, P; Dayani, O; Mehdipour, M; Morovat, M

    2015-02-01

    The aim of this study was to evaluate the effects of processing of lemon pulp with Saccharomyces cerevisiae on physical properties, chemical composition, digestion coefficients and blood parameters. Eight adult male Raeini goats were used in a 28-day period. The experimental design was a completely randomised design with two treatments and four replicates. The first 21 days were for adaptation, and the last 7 days were for collecting samples. The animals were housed in individual metabolic cages equipped with a urine-faeces separator and were fed with diet containing alfalfa hay (60%) and lemon pulp (40%) at the maintenance level. Collected data were subjected to analysis of completely randomised design. With diet containing processed lemon pulp, functional specific gravity, bulk density, soluble dry matter, percentage of crude protein, neutral detergent fibre (NDF), acid detergent fibre and crude ash were significantly increased and water-holding capacity, insoluble dry matter, insoluble ash percentage of dry matter, organic matter, crude fat, non-fibrous carbohydrates and nitrogen-free extract were significantly decreased (p lemon pulp (p lemon pulp, digestibility of crude protein and NDF was higher (p lemon pulp with S. cerevisiae improved the physical characteristics and increased the percentage of crude protein and the digestion coefficients of protein and NDF. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  17. Vertical movement patterns and ontogenetic niche expansion in the tiger shark, Galeocerdo cuvier.

    Science.gov (United States)

    Afonso, André S; Hazin, Fábio H V

    2015-01-01

    Sharks are top predators in many marine ecosystems and can impact community dynamics, yet many shark populations are undergoing severe declines primarily due to overfishing. Obtaining species-specific knowledge on shark spatial ecology is important to implement adequate management strategies for the effective conservation of these taxa. This is particularly relevant concerning highly-mobile species that use wide home ranges comprising coastal and oceanic habitats, such as tiger sharks, Galeocerdo cuvier. We deployed satellite tags in 20 juvenile tiger sharks off northeastern Brazil to assess the effect of intrinsic and extrinsic factors on depth and temperature usage. Sharks were tracked for a total of 1184 d and used waters up to 1112 m in depth. The minimum temperature recorded equaled 4°C. All sharks had a clear preference for surface (sharks used mostly shallow (sharks spending considerably more time in surface (shark habitat was observed, with generalized linear models estimating a ~4-fold increase in maximum diving depth from 150- to 300-cm size-classes. The time spent in the upper 5 m of the water column did not vary ontogenetically but shark size was the most important factor explaining the utilization of deeper water layers. Young-of-the-year tiger sharks seem to associate with shallow, neritic habitats but they progressively move into deeper oceanic habitats as they grow larger. Such an early plasticity in habitat use could endow tiger sharks with access to previously unavailable prey, thus contributing to a wider ecological niche.

  18. The traditional irrigation technique of Lake Garda lemon--houses (Northern Italy)

    Science.gov (United States)

    Barontini, Stefano; Vitale, Nicola; Fausti, Federico; Bettoni, Barbara; Bonati, Sara; Peli, Marco; Pietta, Antonella; Tononi, Marco; Ranzi, Roberto

    2016-04-01

    Between 16th and 19th centuries the North-Western side of Lake Garda was seat of an important district which, at the time of its maximum splendour between 18th and 19th centuries, produced and exported lemons and citrus even toward the Northern Europe and the Russia. The limonaie del Garda (Lake-Garda lemon-houses), the local name of the citrus orchards, were settled on terraces built on steep slopes, with landfill taken from the Eastern side of the lake, and closed by greenhouses during late autumn and winter in order to protect the cultivations. The terraces were built nearby streams, they were South-Eastern exposed and protected by walls from the cold winds. Thanks in fact to the Lake Garda microclimate, lemon trees were not cultivated in pots, as in the typical orangeries of mid-latitudes Europe, but directly in the soil. Here the citrus cultivation technique reached a remarkably high degree of standardisation, with local cultivar as the Madernino or lemon from Maderno, and it involved, as in modern industrial districts, all the surrounding land in order to satisfy the needing of required materials to build the terraces, the walls, the greenhouses and the wooden frames to hold the branches laden with fruits. Due to the great water requirement of lemon trees during summer, which is estimated to range from 150 to 300 ℓ every ten days, the water management played a key role in the cultivation technique. The traditional irrigation technique was standardized as well. During our surveys, we observed that most of the lemon-houses still conserve little stone flumes along the walls upslope to the terraces, with spillways every adult tree, i.e. about every 4 m. The flumes were filled with water taken from an upstream reservoir, built nearby a stream. The spillways were activated with a backwater obtained by means of a sand bag placed within the flume, just downstream to the spillway itself. In order to avoid any excavation, spilled water was driven to the base of each

  19. A study of the drying effect on lemon slices using a closed-type solar dryer

    Energy Technology Data Exchange (ETDEWEB)

    Ho-Hsien Chen; Hernandez, C.E.; Tzou-Chi Huang [National Pingtung University of Science and Technology (China). Dept. of Food Science

    2005-01-01

    An experimental closed-type dryer associated with a photovoltaic system (PV) was developed. The transparent drying cabinet was designed with high transmittance glass to decrease the reflection of direct sunlight and to offer extra direct solar heating on the raw material during drying. Parallel wiring with a local electrical grid was necessary for switching purposes if there is insufficient battery backup during peak operation. Lemon slices were dried using the closed-type solar dryer and results were compared with hot air drying at 60{sup o}C. The results indicate that the dried lemon slices using a closed-type solar dryer has better general levels of quality in terms of sensory parameters. (author)

  20. Immunoglobulins in the eggs of the nurse shark, Ginglymostoma cirratum.

    Science.gov (United States)

    Haines, Ashley N; Flajnik, Martin F; Rumfelt, Lynn L; Wourms, John P

    2005-01-01

    Elasmobranchs, which include the sharks, skates, and rays, emerged over 450 million years ago and are the oldest vertebrates to possess an adaptive immune system. They have evolved diverse reproductive modes, with a variety of physiological adaptations that enhance reproductive success. The nurse shark, Ginglymostoma cirratum, is an aplacental, viviparous elasmobranch in which the egg and its associated vitelline vasculature are the primary route for maternal-embryonic interactions. During gestation, nurse shark embryos hatch from their eggcases and develop free in the uterus, which is flushed regularly with seawater. Similar to higher vertebrates, embryonic and neonatal nurse sharks possess an immune system that is not fully competent. In birds and bony fishes, maternal immunoglobulins (Ig) stored in the egg during oogenesis confer protective immunity to embryos during gestation. However, early research suggested that such transfer of passive immunity does not occur in sharks. To better understand how elasmobranch embryos are protected from waterborne pathogens during this potentially vulnerable time, we have re-examined the existence of Igs in elasmobranch eggs. Using monoclonal antibodies, we establish the presence of two classes of Igs in nurse shark eggs: 7S IgM and IgNAR. The potential transfer of immunoglobulins from elasmobranch eggs is discussed.

  1. Acoustic telemetry reveals cryptic residency of whale sharks

    KAUST Repository

    Cagua, Edgar F.

    2015-04-01

    Althoughwhale sharks (Rhincodon typus) have beendocumentedtomove thousands of kilometres, they are most frequently observed at a few predictable seasonal aggregation sites. The absence of sharks at the surface during visual surveys has led to the assumption that sharks disperse to places unknown during the long \\'off-seasons\\' at most of these locations. Here we compare 2 years of R. typus visual sighting records from Mafia Island in Tanzania to concurrent acoustic telemetry of tagged individuals. Sightings revealed a clear seasonal pattern with a peak between October and February and no sharks observed at other times. By contrast, acoustic telemetry demonstrated yearround residency of R. typus. The sharks use a different habitat in the offseason, swimming deeper and further away from shore, presumably in response to prey distributions. This behavioural change reduces the sharks\\' visibility, giving the false impression that they have left the area.We demonstrate, for the first timeto our knowledge, year-roundresidencyofunprovisioned, individual R. typus at an aggregation site, and highlight the importance of using multiple techniques to study the movement ecology of marine megafauna. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  2. Olfaction Contributes to Pelagic Navigation in a Coastal Shark.

    Science.gov (United States)

    Nosal, Andrew P; Chao, Yi; Farrara, John D; Chai, Fei; Hastings, Philip A

    2016-01-01

    How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities.

  3. Vertebral bomb radiocarbon suggests extreme longevity in white sharks.

    Science.gov (United States)

    Hamady, Li Ling; Natanson, Lisa J; Skomal, Gregory B; Thorrold, Simon R

    2014-01-01

    Conservation and management efforts for white sharks (Carcharodon carcharias) remain hampered by a lack of basic demographic information including age and growth rates. Sharks are typically aged by counting growth bands sequentially deposited in their vertebrae, but the assumption of annual deposition of these band pairs requires testing. We compared radiocarbon (Δ(14)C) values in vertebrae from four female and four male white sharks from the northwestern Atlantic Ocean (NWA) with reference chronologies documenting the marine uptake of (14)C produced by atmospheric testing of thermonuclear devices to generate the first radiocarbon age estimates for adult white sharks. Age estimates were up to 40 years old for the largest female (fork length [FL]: 526 cm) and 73 years old for the largest male (FL: 493 cm). Our results dramatically extend the maximum age and longevity of white sharks compared to earlier studies, hint at possible sexual dimorphism in growth rates, and raise concerns that white shark populations are considerably more sensitive to human-induced mortality than previously thought.

  4. Acoustic telemetry reveals cryptic residency of whale sharks.

    Science.gov (United States)

    Cagua, E Fernando; Cochran, Jesse E M; Rohner, Christoph A; Prebble, Clare E M; Sinclair-Taylor, Tane H; Pierce, Simon J; Berumen, Michael L

    2015-04-01

    Although whale sharks (Rhincodon typus) have been documented to move thousands of kilometres, they are most frequently observed at a few predictable seasonal aggregation sites. The absence of sharks at the surface during visual surveys has led to the assumption that sharks disperse to places unknown during the long 'off-seasons' at most of these locations. Here we compare 2 years of R. typus visual sighting records from Mafia Island in Tanzania to concurrent acoustic telemetry of tagged individuals. Sightings revealed a clear seasonal pattern with a peak between October and February and no sharks observed at other times. By contrast, acoustic telemetry demonstrated year-round residency of R. typus. The sharks use a different habitat in the off-season, swimming deeper and further away from shore, presumably in response to prey distributions. This behavioural change reduces the sharks' visibility, giving the false impression that they have left the area. We demonstrate, for the first time to our knowledge, year-round residency of unprovisioned, individual R. typus at an aggregation site, and highlight the importance of using multiple techniques to study the movement ecology of marine megafauna. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Shark recreational fisheries: Status, challenges, and research needs.

    Science.gov (United States)

    Gallagher, Austin J; Hammerschlag, Neil; Danylchuk, Andy J; Cooke, Steven J

    2017-05-01

    For centuries, the primary manner in which humans have interacted with sharks has been fishing. A combination of their slow-growing nature and high use-values have resulted in population declines for many species around the world, and to date the vast majority of fisheries-related work on sharks has focused on the commercial sector. Shark recreational fishing remains an overlooked area of research despite the fact that these practices are popular globally and could present challenges to their populations. Here we provide a topical overview of shark recreational fisheries, highlighting their history and current status. While recreational fishing can provide conservation benefits under certain circumstances, we focus our discourse on the relatively understudied, potentially detrimental impacts these activities may have on shark physiology, behavior, and fitness. We took this angle given the realized but potentially underestimated significance of recreational fishing for shark conservation management plans and stock assessments, in hopes of creating a dialogue around sustainability. We also present a series of broad and focused research questions and underpin areas of future research need to assist with the development of this emergent area of research.

  6. Isolation and extraction of antimicrobial substances against oral bacteria from lemon peel

    OpenAIRE

    Miyake, Yoshiaki; Hiramitsu, Masanori

    2011-01-01

    We have isolated 4 antibacterial substances that were active against the oral bacteria that cause dental caries and periodontitis, such as Streptococcus mutans, Prevotella intermedia, and Porphyromonas gingivalis, from lemon peel, a waste product in the citrus industry. The isolated substances were identified as 8-geranyloxypsolaren, 5-geranyloxypsolaren, 5-geranyloxy-7-methoxycoumarin, and phloroglucinol 1-β-D-glucopyranoside (phlorin) upon structural analyses. Among these, 8-Geranyloxypsola...

  7. Evaluation of the stability of concentrated emulsions for lemon beverages using sequential experimental designs.

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Abreu Almeida

    Full Text Available The study of the stability of concentrated oil-in-water emulsions is imperative to provide a scientific approach for an important problem in the beverage industry, contributing to abolish the empiricism still present nowadays. The use of these emulsions would directly imply a reduction of transportation costs between production and the sales points, where dilution takes place. The goal of this research was to evaluate the influence of the main components of a lemon emulsion on its stability, aiming to maximize the concentration of oil in the beverage and to correlate its physicochemical characteristics to product stability, allowing an increase of shelf life of the final product. For this purpose, analyses of surface and interface tension, electrokinetic potential, particle size and rheological properties of the emulsions were conducted. A 2(4-1 fractional factorial design was performed with the following variables: lemon oil/water ratio (30% to 50%, starch and Arabic gum concentrations (0% to 30% and dioctyl sodium sulfosuccinate (0 mg/L to 100 mg/L, including an evaluation of the responses at the central conditions of each variable. Sequentially, a full design was prepared to evaluate the two most influential variables obtained in the first plan, in which concentration of starch and gum ranged from 0% to 20%, while concentration of lemon oil/water ratio was fixed at 50%, without dioctyl sodium sulfosuccinate. Concentrated emulsions with stability superior to 15 days were obtained with either starch or Arabic gum and 50% lemon oil. The most stable formulations presented viscosity over 100 cP and ratio between the surface tension of the emulsion and the mucilage of over 1. These two answers were selected, since they better represent the behavior of emulsions in terms of stability and could be used as tools for an initial selection of the most promising formulations.

  8. Evaluation of the stability of concentrated emulsions for lemon beverages using sequential experimental designs.

    Science.gov (United States)

    Almeida, Teresa Cristina Abreu; Larentis, Ariane Leites; Ferraz, Helen Conceição

    2015-01-01

    The study of the stability of concentrated oil-in-water emulsions is imperative to provide a scientific approach for an important problem in the beverage industry, contributing to abolish the empiricism still present nowadays. The use of these emulsions would directly imply a reduction of transportation costs between production and the sales points, where dilution takes place. The goal of this research was to evaluate the influence of the main components of a lemon emulsion on its stability, aiming to maximize the concentration of oil in the beverage and to correlate its physicochemical characteristics to product stability, allowing an increase of shelf life of the final product. For this purpose, analyses of surface and interface tension, electrokinetic potential, particle size and rheological properties of the emulsions were conducted. A 2(4-1) fractional factorial design was performed with the following variables: lemon oil/water ratio (30% to 50%), starch and Arabic gum concentrations (0% to 30%) and dioctyl sodium sulfosuccinate (0 mg/L to 100 mg/L), including an evaluation of the responses at the central conditions of each variable. Sequentially, a full design was prepared to evaluate the two most influential variables obtained in the first plan, in which concentration of starch and gum ranged from 0% to 20%, while concentration of lemon oil/water ratio was fixed at 50%, without dioctyl sodium sulfosuccinate. Concentrated emulsions with stability superior to 15 days were obtained with either starch or Arabic gum and 50% lemon oil. The most stable formulations presented viscosity over 100 cP and ratio between the surface tension of the emulsion and the mucilage of over 1. These two answers were selected, since they better represent the behavior of emulsions in terms of stability and could be used as tools for an initial selection of the most promising formulations.

  9. Production of interstocked 'Pera' sweet orange nursey trees on 'Volkamer' lemon and 'Swingle' citrumelo rootstocks

    OpenAIRE

    Girardi,Eduardo Augusto; Mourão Filho,Francisco de Assis Alves

    2006-01-01

    Incompatibility among certain citrus scion and rootstock cultivars can be avoided through interstocking. 'Pera' sweet orange (Citrus sinensis L. Osbeck) nursery tree production was evaluated on 'Swingle' citrumelo (Poncirus trifoliata (L.) Raf x Citrus paradisi Macf) and 'Volkamer' lemon (Citrus volkameriana Pasquale) incompatible rootstocks, using 'Valencia' and 'Hamlin' sweet oranges (Citrus sinensis L. Osbeck), 'Sunki' mandarin (Citrus sunki Hort. ex Tanaka), and 'Cleopatra' mandarin (Citr...

  10. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Directory of Open Access Journals (Sweden)

    Y. García-Orellana

    2013-01-01

    Full Text Available Field-grown lemon trees (Citrus limon (L. Burm. fil. cv. Fino were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS signal intensity (actual MDS/control treatment MDS threshold values of 1.25 (T1 treatment and 1.35 (T2 treatment, which induced two different drought stress levels. Daily variations in leaf (Yleaf and stem (Ystem water potentials, leaf conductance, net photosynthesis, sap flow (SF and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Yleaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Ystem was seen to be a better plant water status indicator than Yleaf. The difference between the two values of Y (Ystem - Yleaf  = DY was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees.

  11. WELFARE OF BROILERS INGESTING A PRE-SLAUGHTER HYDRIC DIET OF LEMON GRASS

    Directory of Open Access Journals (Sweden)

    AFB Royer

    2015-09-01

    Full Text Available ABSTRACTThe pre-slaughter period is considered critical in broiler production. Several factors contribute to increase the birds' stress, such as handling, harvesting, and transportation, negatively affecting their welfare. This study aimed at evaluating the addition of lemon grass (Cymbopogon citratusStapf to the drinking water of broilers during the pre-slaughter period on their behavior, blood cortisol, and surface temperature. The study was carried out at the experimental farm of the Federal University of Grande Dourados (UFGD, Dourados, MS, Brazil. In total, 2594 broilers were distributed according to a completely randomized experimental design, in a 3x2x2 factorial arrangement, with four replicates per treatment. Treatments consisted of three different lemon grass levels (Cymbopogon citratus Stapf used in the form of an infusion (0, 0.1, and 5 g per L of water, sex (male or female, and genetic strain (Ross(r 308 or Cobb(r 500. The infusion was offered when birds were 42 days old. On that day, blood was collected for blood cortisol level determination, broiler surface temperature was recorded, and an ethogram was applied to register broiler behavior. Blood cortisol level and broiler surface temperature were not affected by treatments (p>0.05. The behavior of beak opening was different between the genetic strains (p<0.05, being more frequent in Ross(r 308 broilers. Lemon grass water content did not affect broilers' surface temperature when consumed during the pre-slaughter period.

  12. Preference mapping of lemon lime carbonated beverages with regular and diet beverage consumers.

    Science.gov (United States)

    Leksrisompong, P P; Lopetcharat, K; Guthrie, B; Drake, M A

    2013-02-01

    The drivers of liking of lemon-lime carbonated beverages were investigated with regular and diet beverage consumers. Ten beverages were selected from a category survey of commercial beverages using a D-optimal procedure. Beverages were subjected to consumer testing (n = 101 regular beverage consumers, n = 100 diet beverage consumers). Segmentation of consumers was performed on overall liking scores followed by external preference mapping of selected samples. Diet beverage consumers liked 2 diet beverages more than regular beverage consumers. There were no differences in the overall liking scores between diet and regular beverage consumers for other products except for a sparkling beverage sweetened with juice which was more liked by regular beverage consumers. Three subtle but distinct consumer preference clusters were identified. Two segments had evenly distributed diet and regular beverage consumers but one segment had a greater percentage of regular beverage consumers (P beverage consumers) did not have a large impact on carbonated beverage liking. Instead, mouthfeel attributes were major drivers of liking when these beverages were tested in a blind tasting. Preference mapping of lemon-lime carbonated beverage with diet and regular beverage consumers allowed the determination of drivers of liking of both populations. The understanding of how mouthfeel attributes, aromatics, and basic tastes impact liking or disliking of products was achieved. Preference drivers established in this study provide product developers of carbonated lemon-lime beverages with additional information to develop beverages that may be suitable for different groups of consumers. © 2013 Institute of Food Technologists®

  13. The sixgill shark Hexanchus griseus is one of the most common ...

    African Journals Online (AJOL)

    denise

    2002-11-01

    Pisces, Selachii) de Angola. Notas Cent. Biol. Aquat. Trop., Lisboa 32: 1–23. SPRINGER, S. 1967 — Social organization of shark populations. In Sharks, Skates, and Rays. Gilbert, P. W., Mathewson, R. F. and D. P. Rall (Eds).

  14. 76 FR 65673 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Correction

    Science.gov (United States)

    2011-10-24

    ... these shark stocks and end overfishing, as necessary. The notice provided an incorrect date for a...' intent to undertake rulemaking to rebuild and/or end overfishing of these Atlantic shark stocks and to...

  15. Acoustic Monitoring of a Previously Unstudied Whale Shark Aggregation in the Red Sea

    KAUST Repository

    Cochran, Jesse

    2012-01-01

    in the area and to inform local management. Continued study will add to the collective knowledge on Red Sea whale sharks, including the population dynamics within the region and how they interact with the global whale shark community.

  16. Eocene squalomorph sharks (Chondrichthyes, Elasmobranchii) from Antarctica

    Science.gov (United States)

    Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A.; Kriwet, Jürgen

    2017-10-01

    Rare remains of predominantly deep-water sharks of the families Hexanchidae, Squalidae, Dalatiidae, Centrophoridae, and Squatinidae are described from the Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula, which has yielded the most abundant chondrichthyan assemblage from the Southern Hemisphere to date. Previously described representatives of Hexanchus sp., Squalus weltoni, Squalus woodburnei, Centrophorus sp., and Squatina sp. are confirmed and dental variations are documented. Although the teeth of Squatina sp. differ from other Palaeogene squatinid species, we refrain from introducing a new species. A new dalatiid taxon, Eodalatias austrinalis gen. et sp. nov. is described. This new material not only increases the diversity of Eocene Antarctic elasmobranchs but also allows assuming that favourable deep-water habitats were available in the Eocene Antarctic Ocean off Antarctica in the Eocene. The occurrences of deep-water inhabitants in shallow, near-coastal waters of the Antarctic Peninsula agrees well with extant distribution patterns.

  17. Eocene squalomorph sharks (Chondrichthyes, Elasmobranchii) from Antarctica.

    Science.gov (United States)

    Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A; Kriwet, Jürgen

    2017-10-01

    Rare remains of predominantly deep-water sharks of the families Hexanchidae, Squalidae, Dalatiidae, Centrophoridae, and Squatinidae are described from the Eocene La Meseta Formation, Seymour Island, Antarctic Peninsula, which has yielded the most abundant chondrichthyan assemblage from the Southern Hemisphere to date. Previously described representatives of Hexanchus sp., Squalus weltoni , Squalus woodburnei , Centrophorus sp., and Squatina sp. are confirmed and dental variations are documented. Although the teeth of Squatina sp. differ from other Palaeogene squatinid species, we refrain from introducing a new species. A new dalatiid taxon, Eodalatias austrinalis gen. et sp. nov. is described. This new material not only increases the diversity of Eocene Antarctic elasmobranchs but also allows assuming that favourable deep-water habitats were available in the Eocene Antarctic Ocean off Antarctica in the Eocene. The occurrences of deep-water inhabitants in shallow, near-coastal waters of the Antarctic Peninsula agrees well with extant distribution patterns.

  18. Long-Term Changes in Species Composition and Relative Abundances of Sharks at a Provisioning Site

    OpenAIRE

    Brunnschweiler, Juerg M.; Abrantes, Kátya G.; Barnett, Adam

    2014-01-01

    Diving with sharks, often in combination with food baiting/provisioning, has become an important product of today's recreational dive industry. Whereas the effects baiting/provisioning has on the behaviour and abundance of individual shark species are starting to become known, there is an almost complete lack of equivalent data from multi-species shark diving sites. In this study, changes in species composition and relative abundances were determined at the Shark Reef Marine Reserve, a multi-...

  19. Llinas’ Phase Reset Mechanism Delays the Onset of Chaos in Shark and Dolphin Wall Turbulence

    Science.gov (United States)

    2014-02-10

    the results of the modeling of chaos control by sharks . Skins of great white ,33 Atlantic sharpnose,36 and tiger shark37 dermal denticles (dd), with...13. c: Dermal denticles (diamond-shaped scales) of great white shark ; depending on species, there may be three to six riblets per scale (five to...Denticles of Great White Shark ," Electron Microscope Unit, University of Cape Town, Smithsonian Museum of Natural History, http://ocean.si.edu/ocean

  20. Development of New Lemon-Lime Flavored Beverage for OGTT: Acceptability and Reproducibility.

    Science.gov (United States)

    Chotwanvirat, Phawinpon; Thewjitcharoen, Yotsapon; Parksook, Wyn; Krittiyawong, Sirinate; Hutaphat, Kritchana; Nakasatien, Soontaree; Kaocharoen, Sming; Himathongkam, Thep

    2016-05-01

    The oral glucose tolerance test (OGTT) is essential procedure in both screening and diagnosis of impaired glucose tolerance (IGT), impaired fasting glucose (IFG) and diabetes mellitus (DM), but it is not easy to perform because of intense sweetness of the 75-g glucose test beverage causing abdominal discomfort post-testing. Therefore, the new formula of non-carbonated lemon-lime flavored beverage was developed to increase its palatability and better compliance. To develop a new non-carbonated lemon-lime flavored beverage to replace the standard beverage for OGTT Subsequently, the diagnostic value and acceptability between the new formula and the traditional 75-g OGTT formula were compared in healthy subjects. The new lemon-lime flavored formula was developed to replace the standard beverage for OGTT by adding 1,000 milligram of citric acid and 0.03 gram of lime flavor to 75 gram of anhydrous glucose to a final volume of 300 ml. The study was conducted in 30 healthy subjects who underwent the traditional 75-gram OGTT test and the new formula of OGTT beverage one week later, or vice versa, to access acceptability, indices markers of insulin secretion, and insulin sensitivity. Palatability was determined by rating on a 9-point Hedonic Scale. Thirty healthy subjects (15 females) with the age of 33.2 ± 7.5 years and body mass index of 22.9 ± 3.5 kg/m² were enrolled. No significant difference was found between plasma glucose in 0, 30, 60, 90, and 120 minutes, insulin level (0 and 120 minutes) and four insulin surrogate markers in both traditional 75-gram OGTT and new formula of lemon-lime flavored OGTT beverage. The overall satisfaction score of the new formula OGTT was better when compared with the scores of the traditional OGTT (7.1 ± 1.8 vs. 4.7 ± 2.0). Only one subject complained about abdominal discomfort in both episode of OGTT CONCLUSION: The modified lemon-lime flavored beverage for OGTT demonstrated better acceptance in the subjects without difference in

  1. 78 FR 24148 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2013-04-24

    ... declared that the status of the dusky shark stock is still overfished and still experiencing overfishing (i... rebuilding and ending overfishing of dusky sharks. This EIS would assess the potential effects on the human environment of action to rebuild and end overfishing of the dusky shark stock, consistent with the Magnuson...

  2. Sharks caught in the protective gill nets off KwaZulu-Natal, South ...

    African Journals Online (AJOL)

    Between 1978 and 1999, a total of 5 626 dusky sharks Carcharhinus obscurus, constituting 20% of the total shark catch, was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 256 sharks (SD = 107.5, range 129–571). There was no significant linear trend in catch rate with time.

  3. 77 FR 32036 - Atlantic Highly Migratory Species; Commercial Porbeagle Shark Fishery Closure

    Science.gov (United States)

    2012-05-31

    ...-XC044 Atlantic Highly Migratory Species; Commercial Porbeagle Shark Fishery Closure AGENCY: National...: Temporary rule; fishery closure. SUMMARY: NMFS is closing the commercial fishery for porbeagle sharks. This... available quota. DATES: The commercial porbeagle shark fishery is closed effective 11:30 p.m. local time May...

  4. 75 FR 53871 - Atlantic Highly Migratory Species; Inseason Action To Close the Commercial Porbeagle Shark Fishery

    Science.gov (United States)

    2010-09-02

    ... Porbeagle Shark Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric... for porbeagle sharks. This action is necessary because landings for the 2010 fishing season has reached at least 80 percent of the available quota. DATES: The commercial porbeagle shark fishery is...

  5. 78 FR 73500 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2013-12-06

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., February, and March of 2014. Certain fishermen and shark dealers are required to attend a workshop to meet...

  6. 78 FR 54456 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2013-09-04

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., November, and December of 2013. Certain fishermen and shark dealers are required to attend a workshop to...

  7. 76 FR 23935 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2011-04-29

    .... 110120049-1144-01] RIN 0648-BA69 Atlantic Highly Migratory Species; Atlantic Shark Management Measures... retention, transshipping, landing, storing, or selling of hammerhead sharks in the family Sphyrnidae (except for Sphyrna tiburo) and oceanic whitetip sharks (Carcharhinus longimanus) caught in association with...

  8. 77 FR 32950 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2012-06-04

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., August, and September of 2012. Certain fishermen and shark dealers are required to attend a workshop to...

  9. 75 FR 10217 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2010-03-05

    ... Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and Identification... (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: NMFS announces free Atlantic Shark... April, May, and June of 2010. Certain fishermen and shark dealers are required to attend a workshop to...

  10. 77 FR 12574 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2012-03-01

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., May, and June of 2012. Certain fishermen and shark dealers are required to attend a workshop to meet...

  11. 77 FR 55464 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2012-09-10

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., November, and December of 2012. Certain fishermen and shark dealers are required to attend a workshop to...

  12. 78 FR 52487 - Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2013-08-23

    .... 130402317-3707-01] RIN 0648-XC611 Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2014 fishing season for the Atlantic commercial shark... management measures to provide, to the extent practicable, fishing opportunities for commercial shark...

  13. 76 FR 11679 - Drawbridge Operation Regulation; Shark River (South Channel), Belmar, NJ

    Science.gov (United States)

    2011-03-03

    ... Operation Regulation; Shark River (South Channel), Belmar, NJ AGENCY: Coast Guard, DHS. ACTION: Notice of... temporary deviation from the regulations governing the operation of the S71 Bridge across Shark River (South... Bridge, a bascule lift drawbridge, across Shark River (South Channel), at mile 0.8, in Belmar, NJ, has a...

  14. 77 FR 73451 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2012-12-10

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., February, and March of 2013. Certain fishermen and shark dealers are required to attend a workshop to meet...

  15. 75 FR 44938 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

    Science.gov (United States)

    2010-07-30

    ... Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery AGENCY: National... moratorium on fishing for Atlantic coastal sharks in the State waters of New Jersey. NMFS canceled the... Fisheries Commission's (Commission) Interstate Fishery Management Plan for Atlantic Coastal Sharks (Coastal...

  16. 78 FR 15709 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2013-03-12

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., May, and June of 2013. Certain fishermen and shark dealers are required to attend a workshop to meet...

  17. 75 FR 57235 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2010-09-20

    .... 100825390-0431-01] RIN 0648-BA17 Atlantic Highly Migratory Species; Atlantic Shark Management Measures... on potential adjustments to the regulations governing the U.S. Atlantic shark fishery to address several specific issues currently affecting management of the shark fishery and to identify specific goals...

  18. 75 FR 74693 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2010-12-01

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., February, and March of 2011. Certain fishermen and shark dealers are required to attend a workshop to meet...

  19. 75 FR 50715 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures; Amendment 3

    Science.gov (United States)

    2010-08-17

    ... [Docket No. 080519678-0313-03] RIN 0648-AW65 Atlantic Highly Migratory Species; Atlantic Shark Management... for adjusting annual shark quotas based on over- and underharvests. This correction makes a change to...), instruction 12a revised 50 CFR 635.27 (b)(1)(i) through (v), relating to, among other things, pelagic shark...

  20. 77 FR 37647 - Atlantic Highly Migratory Species; Silky Shark Management Measures

    Science.gov (United States)

    2012-06-22

    .... 120416016-2151-01] RIN 0648-BB96 Atlantic Highly Migratory Species; Silky Shark Management Measures AGENCY..., transshipping, or landing of silky sharks (Carcharhinus falciformis) caught in association with ICCAT fisheries... sharks with bottom longline, gillnet, or handgear; nor would the rule affect recreational fishermen as...

  1. 76 FR 34209 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2011-06-13

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., August, and September of 2011. Certain fishermen and shark dealers are required to attend a workshop to...

  2. 77 FR 35357 - Atlantic Highly Migratory Species; Commercial Atlantic Region Non-Sandbar Large Coastal Shark...

    Science.gov (United States)

    2012-06-13

    ... Highly Migratory Species; Commercial Atlantic Region Non-Sandbar Large Coastal Shark Fishery Opening Date... commercial Atlantic region non-sandbar large coastal shark fishery. This action is necessary to inform... large coastal shark fishery will open on July 15, 2012. FOR FURTHER INFORMATION CONTACT: Karyl Brewster...

  3. Pilot study on behaviour of sharks around Saba using acoustic telemetry - Progress report 2014

    NARCIS (Netherlands)

    Winter, H.V.; Vink, D.; Beek, van I.J.M.

    2015-01-01

    Worldwide many shark populations are in strong decline mainly due to fisheries. Population status of sharks in the Caribbean is still poorly known. In order to be able to take effective measures to protect sharks, insight in their spatial behaviour during different life stages is required. Do marine

  4. 76 FR 72383 - Atlantic Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2011-11-23

    ...-BA17 Atlantic Highly Migratory Species; Atlantic Shark Management Measures AGENCY: National Marine... plan (FMP) amendment that would consider catch shares for the Atlantic shark fisheries. The comment... potential catch shares programs in the Atlantic shark fisheries. Additionally, NMFS is extending the comment...

  5. 76 FR 53343 - Atlantic Highly Migratory Species; Commercial Porbeagle Shark Fishery Closure

    Science.gov (United States)

    2011-08-26

    ...-XA658 Atlantic Highly Migratory Species; Commercial Porbeagle Shark Fishery Closure AGENCY: National...: Temporary rule; fishery closure. SUMMARY: NMFS is closing the commercial fishery for porbeagle sharks. This... available quota. DATES: The commercial porbeagle shark fishery is closed effective 11:30 p.m. local time...

  6. 78 FR 54195 - Atlantic Highly Migratory Species; Atlantic Commercial Shark Fisheries

    Science.gov (United States)

    2013-09-03

    .... 110831548-3536-02] RIN 0648-XC836 Atlantic Highly Migratory Species; Atlantic Commercial Shark Fisheries...) dressed weight (dw) of non-blacknose small coastal shark (SCS) quota from the Atlantic region to the Gulf... Atlantic shark permitted vessels. DATES: The quota transfer is effective from September 2, 2013 until...

  7. 76 FR 77214 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2011-12-12

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., February, and March of 2012. Certain fishermen and shark dealers are required to attend a workshop to meet...

  8. 76 FR 67121 - Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2011-10-31

    .... 110913585-1625-01] RIN 0648-BB36 Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2012 fishing season for the Atlantic commercial shark... 2011 Atlantic commercial shark fishing seasons. In addition, NMFS proposes season openings based on...

  9. 75 FR 29991 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2010-05-28

    ... Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and Identification... (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., August, and September of 2010. Certain fishermen and shark dealers are required to attend a workshop to...

  10. 76 FR 11762 - Schedules for Atlantic Shark Identification Workshops and Protected Species Safe Handling...

    Science.gov (United States)

    2011-03-03

    ... for Atlantic Shark Identification Workshops and Protected Species Safe Handling, Release, and... Administration (NOAA), Commerce. ACTION: Notice of public workshops. SUMMARY: Free Atlantic Shark Identification..., May, and June of 2011. Certain fishermen and shark dealers are required to attend a workshop to meet...

  11. 75 FR 22103 - Atlantic Coastal Fisheries Cooperative Management Act Provisions; Atlantic Coastal Shark Fishery

    Science.gov (United States)

    2010-04-27

    ... species of sharks, including basking, great hammerhead, scalloped hammerhead, white, dusky, tiger, sand... Plan for Atlantic Coastal Sharks (Plan) and that the measures New Jersey has failed to implement and enforce are necessary for the conservation of the shark resource. This determination is consistent with...

  12. 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.

  13. 50 CFR 635.24 - Commercial retention limits for sharks and swordfish.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Commercial retention limits for sharks and... Management Measures § 635.24 Commercial retention limits for sharks and swordfish. The retention limits in this section are subject to the quotas and closure provisions in §§ 635.27 and 635.28. (a) Sharks. (1...

  14. Ocean-wide tracking of pelagic sharks reveals extent of overlap with longline fishing hotspots.

    Science.gov (United States)

    Queiroz, Nuno; Humphries, Nicolas E; Mucientes, Gonzalo; Hammerschlag, Neil; Lima, Fernando P; Scales, Kylie L; Miller, Peter I; Sousa, Lara L; Seabra, Rui; Sims, David W

    2016-02-09

    Overfishing is arguably the greatest ecological threat facing the oceans, yet catches of many highly migratory fishes including oceanic sharks remain largely unregulated with poor monitoring and data reporting. Oceanic shark conservation is hampered by basic knowledge gaps about where sharks aggregate across population ranges and precisely where they overlap with fishers. Using satellite tracking data from six shark species across the North Atlantic, we show that pelagic sharks occupy predictable habitat hotspots of high space use. Movement modeling showed sharks preferred habitats characterized by strong sea surface-temperature gradients (fronts) over other available habitats. However, simultaneous Global Positioning System (GPS) tracking of the entire Spanish and Portuguese longline-vessel fishing fleets show an 80% overlap of fished areas with hotspots, potentially increasing shark susceptibility to fishing exploitation. Regions of high overlap between oceanic tagged sharks and longliners included the North Atlantic Current/Labrador Current convergence zone and the Mid-Atlantic Ridge southwest of the Azores. In these main regions, and subareas within them, shark/vessel co-occurrence was spatially and temporally persistent between years, highlighting how broadly the fishing exploitation efficiently "tracks" oceanic sharks within their space-use hotspots year-round. Given this intense focus of longliners on shark hotspots, our study argues the need for international catch limits for pelagic sharks and identifies a future role of combining fine-scale fish and vessel telemetry to inform the ocean-scale management of fisheries.

  15. Laser photogrammetry improves size and demographic estimates for whale sharks

    Science.gov (United States)

    Richardson, Anthony J.; Prebble, Clare E.M.; Marshall, Andrea D.; Bennett, Michael B.; Weeks, Scarla J.; Cliff, Geremy; Wintner, Sabine P.; Pierce, Simon J.

    2015-01-01

    Whale sharks Rhincodon typus are globally threatened, but a lack of biological and demographic information hampers an accurate assessment of their vulnerability to further decline or capacity to recover. We used laser photogrammetry at two aggregation sites to obtain more accurate size estimates of free-swimming whale sharks compared to visual estimates, allowing improved estimates of biological parameters. Individual whale sharks ranged from 432–917 cm total length (TL) (mean ± SD = 673 ± 118.8 cm, N = 122) in southern Mozambique and from 420–990 cm TL (mean ± SD = 641 ± 133 cm, N = 46) in Tanzania. By combining measurements of stranded individuals with photogrammetry measurements of free-swimming sharks, we calculated length at 50% maturity for males in Mozambique at 916 cm TL. Repeat measurements of individual whale sharks measured over periods from 347–1,068 days yielded implausible growth rates, suggesting that the growth increment over this period was not large enough to be detected using laser photogrammetry, and that the method is best applied to estimating growth rates over longer (decadal) time periods. The sex ratio of both populations was biased towards males (74% in Mozambique, 89% in Tanzania), the majority of which were immature (98% in Mozambique, 94% in Tanzania). The population structure for these two aggregations was similar to most other documented whale shark aggregations around the world. Information on small (sharks, mature individuals, and females in this region is lacking, but necessary to inform conservation initiatives for this globally threatened species. PMID:25870776

  16. Shark Interactions With Directed and Incidental Fisheries in the Northeast Pacific Ocean: Historic and Current Encounters, and Challenges for Shark Conservation.

    Science.gov (United States)

    King, Jackie; McFarlane, Gordon A; Gertseva, Vladlena; Gasper, Jason; Matson, Sean; Tribuzio, Cindy A

    For over 100 years, sharks have been encountered, as either directed catch or incidental catch, in commercial fisheries throughout the Northeast Pacific Ocean. A long-standing directed fishery for North Pacific Spiny Dogfish (Squalus suckleyi) has occurred and dominated shark landings and discards. Other fisheries, mainly for shark livers, have historically targeted species including Bluntnose Sixgill Shark (Hexanchus griseus) and Tope Shark (Galeorhinus galeus). While incidental catches of numerous species have occurred historically, only recently have these encounters been reliably enumerated in commercial and recreational fisheries. In this chapter we present shark catch statistics (directed and incidental) for commercial and recreational fisheries from Canadian waters (off British Columbia), southern US waters (off California, Oregon, and Washington), and northern US waters (off Alaska). In total, 17 species of sharks have collectively been encountered in these waters. Fishery encounters present conservation challenges for shark management, namely, the need for accurate catch statistics, stock delineation, life history parameter estimates, and improved assessments methods for population status and trends. Improvements in management and conservation of shark populations will only come with the further development of sound science-based fishery management practices for both targeted and incidental shark fisheries. © 2017 Elsevier Ltd All rights reserved.

  17. Conservation and variation in the feeding mechanism of the spiny dogfish squalus acanthias

    Science.gov (United States)

    Wilga; Motta

    1998-05-01

    Changes in the feeding mechanism with feeding behavior were investigated using high-speed video and electromyography to examine the kinematics and motor pattern of prey capture, manipulation and transport in the spiny dogfish Squalus acanthias (Squalidae: Squaliformes). In this study, Squalus acanthias used both suction and ram behaviors to capture and manipulate prey, while only suction was used to transport prey. The basic kinematic feeding sequence observed in other aquatic-feeding lower vertebrates is conserved in the spiny dogfish. Prey capture, bite manipulation and suction transport events are characterized by a common pattern of head movements and motor activity, but are distinguishable by differences in duration and relative timing. In general, capture events are longer in duration than manipulation and transport events, as found in other aquatic-feeding lower vertebrates. Numerous individual effects were found, indicating that individual sharks are capable of varying head movements and motor activity among successful feeding events. Upper jaw protrusion in the spiny dogfish is not restricted by its orbitostylic jaw suspension; rather, the upper jaw is protruded by 30 % of its head length, considerably more than in the lemon shark Negaprion brevirostris (Carcharhinidae: Carcharhiniformes) (18 %) with its hyostylic jaw suspension. One function of upper jaw protrusion is to assist in jaw closure by protruding the upper jaw as well as elevating the lower jaw to close the gape, thus decreasing the time to jaw closure. The mechanism of upper jaw protrusion was found to differ between squaliform and carcharhiniform sharks. Whereas the levator palatoquadrati muscle assists in retracting the upper jaw in the spiny dogfish, it assists in protruding the upper jaw in the lemon shark. This study represents the first comprehensive electromyographic and kinematic analysis of the feeding mechanism in a squaliform shark.

  18. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away) and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  19. Residency and spatial use by reef sharks of an isolated seamount and its implications for conservation.

    Directory of Open Access Journals (Sweden)

    Adam Barnett

    Full Text Available Although marine protected areas (MPAs are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (~14 km away and one grey reef shark completed a round trip of ~250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef.

  20. Residency and Spatial Use by Reef Sharks of an Isolated Seamount and Its Implications for Conservation

    Science.gov (United States)

    Barnett, Adam; Abrantes, Kátya G.; Seymour, Jamie; Fitzpatrick, Richard

    2012-01-01

    Although marine protected areas (MPAs) are a common conservation strategy, these areas are often designed with little prior knowledge of the spatial behaviour of the species they are designed to protect. Currently, the Coral Sea area and its seamounts (north-east Australia) are under review to determine if MPAs are warranted. The protection of sharks at these seamounts should be an integral component of conservation plans. Therefore, knowledge on the spatial ecology of sharks at the Coral Sea seamounts is essential for the appropriate implementation of management and conservation plans. Acoustic telemetry was used to determine residency, site fidelity and spatial use of three shark species at Osprey Reef: whitetip reef sharks Triaenodon obesus, grey reef sharks Carcharhinus amblyrhynchos and silvertip sharks Carcharhinus albimarginatus. Most individuals showed year round residency at Osprey Reef, although five of the 49 individuals tagged moved to the neighbouring Shark Reef (∼14 km away) and one grey reef shark completed a round trip of ∼250 km to the Great Barrier Reef. Additionally, individuals of white tip and grey reef sharks showed strong site fidelity to the areas they were tagged, and there was low spatial overlap between groups of sharks tagged at different locations. Spatial use at Osprey Reef by adult sharks is generally restricted to the north-west corner. The high residency and limited spatial use of Osprey Reef suggests that reef sharks would be highly vulnerable to targeted fishing pressure and that MPAs incorporating no-take of sharks would be effective in protecting reef shark populations at Osprey and Shark Reef. PMID:22615782

  1. Biased immunoglobulin light chain gene usage in the shark1

    Science.gov (United States)

    Iacoangeli, Anna; Lui, Anita; Naik, Ushma; Ohta, Yuko; Flajnik, Martin; Hsu, Ellen

    2015-01-01

    This study of a large family of kappa light (L) chain clusters in nurse shark completes the characterization of its classical immunoglobulin (Ig) gene content (two heavy chain classes, mu and omega, and four L chain isotopes, kappa, lambda, sigma, and sigma-2). The shark kappa clusters are minigenes consisting of a simple VL-JL-CL array, where V to J recombination occurs over a ~500 bp interval, and functional clusters are widely separated by at least 100 kb. Six out of ca. 39 kappa clusters are pre-rearranged in the germline (GL-joined). Unlike the complex gene organization and multistep assembly process of Ig in mammals, each shark Ig rearrangement, somatic or in the germline, appears to be an independent event localized to the minigene. This study examined the expression of functional, non-productive, and sterile transcripts of the kappa clusters compared to the other three L chain isotypes. Kappa cluster usage was investigated in young sharks, and a skewed pattern of split gene expression was observed, one similar in functional and non-productive rearrangements. These results show that the individual activation of the spatially distant kappa clusters is non-random. Although both split and GL-joined kappa genes are expressed, the latter are prominent in young animals and wane with age. We speculate that, in the shark, the differential activation of the multiple isotypes can be advantageously used in receptor editing. PMID:26342033

  2. Biased Immunoglobulin Light Chain Gene Usage in the Shark.

    Science.gov (United States)

    Iacoangeli, Anna; Lui, Anita; Naik, Ushma; Ohta, Yuko; Flajnik, Martin; Hsu, Ellen

    2015-10-15

    This study of a large family of κ L chain clusters in nurse shark completes the characterization of its classical Ig gene content (two H chain isotypes, μ and ω, and four L chain isotypes, κ, λ, σ, and σ-2). The shark κ clusters are minigenes consisting of a simple VL-JL-CL array, where V to J recombination occurs over an ~500-bp interval, and functional clusters are widely separated by at least 100 kb. Six out of ~39 κ clusters are prerearranged in the germline (germline joined). Unlike the complex gene organization and multistep assembly process of Ig in mammals, each shark Ig rearrangement, somatic or in the germline, appears to be an independent event localized to the minigene. This study examined the expression of functional, nonproductive, and sterile transcripts of the κ clusters compared with the other three L chain isotypes. κ cluster usage was investigated in young sharks, and a skewed pattern of split gene expression was observed, one similar in functional and nonproductive rearrangements. These results show that the individual activation of the spatially distant κ clusters is nonrandom. Although both split and germline-joined κ genes are expressed, the latter are prominent in young animals and wane with age. We speculate that, in the shark, the differential activation of the multiple isotypes can be advantageously used in receptor editing. Copyright © 2015 by The American Association of Immunologists, Inc.

  3. Vulnerability of oceanic sharks as pelagic longline bycatch

    Directory of Open Access Journals (Sweden)

    A.J. Gallagher

    2014-08-01

    Full Text Available Bycatch (the unintentional catch of non-target species or sizes is consistently ranked as one of the greatest threats to marine fish populations; yet species-specific rates of bycatch survival are rarely considered in risk assessments. Regulations often require that bycatch of threatened species be released; but, if animals are already dead, their release serves no conservation purpose. We examined the survival of 12 shark species caught as bycatch in the US Atlantic pelagic longline fishery. Shark survival was evaluated in relation to fishery target (swordfish versus tuna and four operational, environmental, and biological variables to evaluate the underlying mechanisms affecting mortality. Survival estimates ranged from 33% (night shark to 97% (tiger shark with seven of the 12 species being significantly affected by at least one variable. We placed our survival results within a framework that assessed each species’ relative vulnerability by integrating survival estimates with reproductive potential and found that the bigeye thresher, dusky, night, and scalloped hammerhead shark exhibited the highest vulnerabilities to bycatch. We suggest that considering ecological and biological traits of species shows promise for designing effective conservation measures, whereas techniques that reduce fisheries interactions in the first place may be the best strategy for highly vulnerable species.

  4. Acoustic backscatter at a Red Sea whale shark aggregation site

    KAUST Repository

    Hozumi, Aya; Kaartvedt, Stein; Rø stad, Anders; Berumen, Michael L.; Cochran, Jesse E.M.; Jones, Burton

    2018-01-01

    An aggregation of sexually immature whale sharks occurs at a coastal submerged reef near the Saudi Arabian Red Sea coast each spring. We tested the hypothesis that these megaplanktivores become attracted to a prey biomass peak coinciding with their aggregation. Acoustic backscatter of the water column at 120 kHz and 333 kHz –a proxy for potential prey biomass –was continuously measured spanning the period prior to, during, and subsequent to the seasonal whale shark aggregations. No peak in acoustic backscatter was observed at the time of the aggregation. However, we observed a decrease in acoustic backscatter in the last days of deployment, which coincided the trailing end of whale shark season. Organisms forming the main scattering layer performed inverse diel vertical migration, with backscatter peaking at mid-depths during the day and in the deeper half of the water column at night. Target strength analyses suggested the backscatter was likely composed of fish larvae. Subsurface foraging behavior of the whale sharks within this aggregation has not been described, yet this study does not support the hypothesis that seasonal peaks in local whale shark abundance correspond to similar peaks in prey availability.

  5. Acoustic backscatter at a Red Sea whale shark aggregation site

    KAUST Repository

    Hozumi, Aya

    2018-03-28

    An aggregation of sexually immature whale sharks occurs at a coastal submerged reef near the Saudi Arabian Red Sea coast each spring. We tested the hypothesis that these megaplanktivores become attracted to a prey biomass peak coinciding with their aggregation. Acoustic backscatter of the water column at 120 kHz and 333 kHz –a proxy for potential prey biomass –was continuously measured spanning the period prior to, during, and subsequent to the seasonal whale shark aggregations. No peak in acoustic backscatter was observed at the time of the aggregation. However, we observed a decrease in acoustic backscatter in the last days of deployment, which coincided the trailing end of whale shark season. Organisms forming the main scattering layer performed inverse diel vertical migration, with backscatter peaking at mid-depths during the day and in the deeper half of the water column at night. Target strength analyses suggested the backscatter was likely composed of fish larvae. Subsurface foraging behavior of the whale sharks within this aggregation has not been described, yet this study does not support the hypothesis that seasonal peaks in local whale shark abundance correspond to similar peaks in prey availability.

  6. Introduction to Northeast Pacific Shark Biology, Ecology, and Conservation.

    Science.gov (United States)

    Lowry, Dayv; Larson, Shawn E

    Sharks are iconic, sometimes apex, predators found in every ocean and, as a result, they have featured prominently in the mythology, history, and fisheries of diverse human cultures around the world. Because of their regional significance to fisheries and ecological role as predators, and as a result of concern over long-term stability of their populations, there has been an increasing amount of work focused on shark conservation in recent decades. This volume highlights the biodiversity and biological attributes of, and conservation efforts targeted at, populations of sharks that reside in the Northeast Pacific Ocean bordering the west coast of the United States and Canada, one of the most economically and ecologically important oceanic regions in the world. A companion volume addresses details of fisheries and ecotourism in the same region, as well as delving into the relationship between captive husbandry of sharks and education/outreach efforts aimed at fostering a conservation mindset in the public at large. Together, these volumes provide readers a detailed backdrop against which to consider their own actions, and those of resource managers, academics, and educators, as they relate to the long-term conservation of sharks and their relatives. © 2017 Elsevier Ltd. All rights reserved.

  7. Lemon detox diet reduced body fat, insulin resistance, and serum hs-CRP level without hematological changes in overweight Korean women.

    Science.gov (United States)

    Kim, Mi Joung; Hwang, Jung Hyun; Ko, Hyun Ji; Na, Hye Bock; Kim, Jung Hee

    2015-05-01

    The lemon detox program is a very low-calorie diet which consists of a mixture of organic maple and palm syrups, and lemon juice for abstinence period of 7 days. We hypothesized that the lemon detox program would reduce body weight, body fat mass, thus lowering insulin resistance and known risk factors of cardiovascular disease. We investigated anthropometric indices, insulin sensitivity, levels of serum adipokines, and inflammatory markers in overweight Korean women before and after clinical intervention trial. Eighty-four premenopausal women were randomly divided into 3 groups: a control group without diet restriction (Normal-C), a pair-fed placebo diet group (Positive-C), and a lemon detox diet group (Lemon-D). The intervention period was 11 days total: 7 days with the lemon detox juice or the placebo juice, and then 4 days with transitioning food. Changes in body weight, body mass index, percentage body fat, and waist-hip ratio were significantly greater in the Lemon-D and Positive-C groups compared to the Normal-C group. Serum insulin level, homeostasis model assessment insulin resistance scores, leptin, and adiponectin levels decreased in the Lemon-D and Positive-C groups. Serum high-sensitive C-reactive protein (hs-CRP) levels were also reduced only in the Lemon-D group. Hemoglobin and hematocrit levels remained stable in the Lemon-D group while they decreased in the Positive-C and Normal-C groups. Therefore, we suppose that the lemon detox program reduces body fat and insulin resistance through caloric restriction and might have a potential beneficial effect on risk factors for cardiovascular disease related to circulating hs-CRP reduction without hematological changes. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. SCREENING FITOKIMIA, AKTIVITAS ANTIOKSIDAN DAN ANTIMIKROBA PADA BUAH JERUK LEMON(Citrus limon DAN JERUK NIPIS (Citrus aurantiifolia

    Directory of Open Access Journals (Sweden)

    Anindya Nirmala Permata

    2018-03-01

    Full Text Available The desire to live healthy by eating natural foods and drinks into the lifestyle of the community. Orange becomes one of the fruits that become functional food to maintain and maintain health. The purpose of this research is to know the difference of antioxidant and antimicrobial activity on Citrus limon and Citrus aurantiifolia. The research method is laboratory experimental research with descriptive analysis. This research was conducted in February-April 2017 at the Laboratory of Plant Biological Microbiology and Plant Chemistry Department of Biology State University of Malang. Phytochemical screening by color reaction method, total phenol with Folin Ciocalteu method, antioxidant activity with DPPH method and antimicrobial activity with disc method. Screening results show the presence of saponins and alkaloids but there are no flavonoids, terpenoids and tannins. Total phenol test showed total phenol content in Lemon (Citrus limon of 110,25 mg GAE / 100ml while in Lime (Citrus aurantiifolia 116,5 mg GAE / 100ml. The antioxidant activity of Lemon Citrus (Citrus limon 49.593 g / ml and Lime (Citrus aurantiifolia 49.589g / ml. Antimicrobial activity test obtained the highest zone of resistance at 100% concentration of each citrus fruit. The conclusion of this study is that there is a difference of antioxidant and antimicrobial activity in both oranges, where the lemon fruits (C.limon antioxidant activity is higher than and Lime (C. aurantiifolia, while the antimicrobial activity of lemon (C. aurantiifolia is higher Rather than lemon (C.limon.

  9. Application of lemon peel essential oil with edible coating agent to prolong shelf life of tofu and strawberry

    Science.gov (United States)

    Rahmawati, Della; Chandra, Mega; Santoso, Stefanus; Puteri, Maria Gunawan

    2017-01-01

    The essential oil of sweet orange, lemon, and key lime peel were analyzed for their antimicrobial activity. The antimicrobial activity of each citrus essential oil with different concentration was assessed using broth macro-dilution against Bacillus sp, Eschericia coli, Rhizopus stolonifer, and Botrytis sp which represented specific spoilage microorganism in tofu and fresh strawberry. Among all the citrus peel essential oils tested, lemon peel essential oil with 0.6% concentration showed significant activity as an antimicrobial agent against Escherichia coli and Bacillus sp. In other hand 1% of lemon peel essential oil is also considered to be the best concentration of inhibiting the Rhizopus Stolonifer and Botrytis sp. Lemon peel essential oil which has the highest antimicrobial activity was combined with two different kind of edible coating agents (cassava starch and sodium alginate) and was applied in both tofu and strawberry to observe whether it had possibility to decrease the degradation rate of tofu and strawberry. The addition of 0.6% and 1% lemon peel essential oil with each of edible coating agents was significantly able to reduce the degradation of tofu and fresh strawberry.

  10. Are Caribbean reef sharks, Carcharhinus perezi, able to perceive human body orientation?

    Science.gov (United States)

    Ritter, Erich K; Amin, Raid

    2014-05-01

    The present study examines the potential capability of Caribbean reef sharks to perceive human body orientation, as well as discussing the sharks' swimming patterns in a person's vicinity. A standardized video method was used to record the scenario of single SCUBA divers kneeling in the sand and the approach patterns of sharks, combined with a control group of two divers kneeling back-to-back. When approaching a single test-subject, significantly more sharks preferred to swim outside the person's field of vision. The results suggest that these sharks are able to identify human body orientation, but the mechanisms used and factors affecting nearest distance of approach remain unclear.

  11. The race against the "septic shark".

    Science.gov (United States)

    Westphal, Martin; Kampmeier, Tim

    2015-01-01

    Great white sharks are responsible for about 10 cases of death annually worldwide, as compared with millions of deaths caused by sepsis. However, the basic principles of avoiding shark attacks and fighting sepsis seem to be similar: avoidance, attention, and speed, if necessary. The present review discusses the current status of the systemic inflammatory response syndrome (SIRS) criteria, which are actually content for discussion because of their low specificity. Current data suggest that one in eight patients with severe sepsis does not fulfill the SIRS criteria and is consequently missed, and therefore the calls for new definitions of sepsis are getting louder. Furthermore, the need for early treatment of sepsis and fast admission to an intensive care unit (ICU) with experienced stuff is reviewed as well as the early and appropriate initiation of therapy, namely antibiotic and volume therapy. A key feature is the analysis of the studies from the so-called "Sepsis Trilogy" (ProCESS, ARISE, and ProMiSe studies), with a focus on the status of early goal-directed therapy (EGDT). The authors of the "Sepsis Trilogy" concluded that there is no benefit regarding survival in septic patients by using EGDT as compared with standard therapy. However, the low mortality of the control groups within the "Sepsis Trilogy" studies as compared with the Rivers et al. study from 2001 leads to the conclusion that there has been an improvement in the therapy of septic patients, most probably due to the early initiation of therapy as a kind of "standard" in sepsis therapy. Finally, the phenomenon of a "large trial disease" is discussed, exemplary in a trial which investigated the maintenance of the "right" mean arterial pressure in sepsis patients. Even if the result of a large randomized trial might be that there is no difference between two study groups, the real exercise is to identify the patient collectives who might benefit or experience harm due to an intervention. In summary, as

  12. Identification and evaluation of shark bycatch in Georgia's commercial shrimp trawl fishery with implications for management

    Science.gov (United States)

    Belcher, C.N.; Jennings, C.A.

    2011-01-01

    Many US states have recreational and commercial fisheries that occur in nursery areas occupied by subadult sharks and can potentially affect their survival. Georgia is one of few US states without a directed commercial shark fishery, but the state has a large, nearshore penaeid shrimp trawl fishery in which small sharks occur as bycatch. During our 1995–1998 investigation of bycatch in fishery-dependent sampling events, 34% of 127 trawls contained sharks. This bycatch totalled 217 individuals from six species, with Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson), the most common and finetooth shark, Carcharhinus isodon (Müller & Henle) and spinner shark, Carcharhinus brevipinna (Müller & Henle), the least common. The highest catch rates for sharks occurred during June and July and coincided with the peak months of the pupping season for many species. Trawl tow speed and tow time did not significantly influence catch rates for shark species. Gear configurations [net type, turtle excluder device (TED), bycatch reduction device] affected catch rates for shark species. Results of this study indicate gear restrictions, a delayed season opening, or reduced bar spacing on TEDs may reduce shark bycatch in this fishery.

  13. High Post-Capture Survival for Sharks, Rays and Chimaeras Discarded in the Main Shark Fishery of Australia?

    Science.gov (United States)

    Braccini, Matias; Van Rijn, Jay; Frick, Lorenz

    2012-01-01

    Most sharks, rays and chimaeras (chondrichthyans) taken in commercial fisheries are discarded (i.e. returned to the ocean either dead or alive). Quantifying the post-capture survival (PCS) of discarded species is therefore essential for the improved management and conservation of this group. For all chondrichthyans taken in the main shark fishery of Australia, we quantified the immediate PCS of individuals reaching the deck of commercial shark gillnet fishing vessels and applied a risk-based method to semi-quantitatively determine delayed and total PCS. Estimates of immediate, delayed and total PCS were consistent, being very high for the most commonly discarded species (Port Jackson shark, Australian swellshark, and spikey dogfish) and low for the most important commercial species (gummy and school sharks). Increasing gillnet soak time or water temperature significantly decreased PCS. Chondrichthyans with bottom-dwelling habits had the highest PCS whereas those with pelagic habits had the lowest PCS. The risk-based approach can be easily implemented as a standard practice of on-board observing programs, providing a convenient first-step assessment of the PCS of all species taken in commercial fisheries. PMID:22384270

  14. High post-capture survival for sharks, rays and chimaeras discarded in the main shark fishery of Australia?

    Science.gov (United States)

    Braccini, Matias; Van Rijn, Jay; Frick, Lorenz

    2012-01-01

    Most sharks, rays and chimaeras (chondrichthyans) taken in commercial fisheries are discarded (i.e. returned to the ocean either dead or alive). Quantifying the post-capture survival (PCS) of discarded species is therefore essential for the improved management and conservation of this group. For all chondrichthyans taken in the main shark fishery of Australia, we quantified the immediate PCS of individuals reaching the deck of commercial shark gillnet fishing vessels and applied a risk-based method to semi-quantitatively determine delayed and total PCS. Estimates of immediate, delayed and total PCS were consistent, being very high for the most commonly discarded species (Port Jackson shark, Australian swellshark, and spikey dogfish) and low for the most important commercial species (gummy and school sharks). Increasing gillnet soak time or water temperature significantly decreased PCS. Chondrichthyans with bottom-dwelling habits had the highest PCS whereas those with pelagic habits had the lowest PCS. The risk-based approach can be easily implemented as a standard practice of on-board observing programs, providing a convenient first-step assessment of the PCS of all species taken in commercial fisheries.

  15. The Influence of Culture on the International Management of Shark Finning

    Science.gov (United States)

    Dell'Apa, Andrea; Chad Smith, M.; Kaneshiro-Pineiro, Mahealani Y.

    2014-08-01

    Shark finning is prohibited in many countries, but high prices for fins from the Asian market help maintain the international black-market and poaching. Traditional shark fin bans fail to recognize that the main driver of fin exploitation is linked to cultural beliefs about sharks in traditional Chinese culture. Therefore, shark finning should be addressed considering the social science approach as part of the fishery management scheme. This paper investigates the cultural significance of sharks in traditional Chinese and Hawaiian cultures, as valuable examples of how specific differences in cultural beliefs can drive individuals' attitudes toward the property of shark finning. We suggest the use of a social science approach that can be useful in the design of successful education campaigns to help change individuals' attitudes toward shark fin consumption. Finally, alternative management strategies for commercial fishers are provided to maintain self-sustainability of local coastal communities.

  16. The use of positive reinforcement in training zebra sharks (Stegostoma fasciatum).

    Science.gov (United States)

    Marranzino, Ashley

    2013-01-01

    Positive reinforcement training (PRT) was used on 4 adult zebra sharks, Stegostoma fasciatum, housed at the Downtown Aquarium, Denver, to determine the ability of zebra sharks to become desensitized to various stimuli associated with veterinary procedures. One male and 3 female sharks were trained for 12 weeks. As a result of PRT, all 4 zebra sharks were desensitized to staying within a closed holding tank off of the main exhibit, the presence of multiple trainers in the closed holding tank, and tactile stimulation. One of the 4 zebra sharks was also successfully desensitized to the presence of a stretcher being brought into the holding tank. All of these procedures are common in veterinary examinations, and it is hoped that desensitization to these stimuli will reduce the stress associated with examinations. The training accomplished has allowed for easier maintenance of the zebra sharks by the aquarium staff and an improvement in the care of the sharks.

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

    Science.gov (United States)

    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.

  18. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Orellana, Y.; Ortuno, M. F.; Conejero, W.; Ruiz-Sanchez, M. C.

    2013-05-01

    Field-grown lemon trees (Citrus limon (L.) Burm. fil. cv. Fino) were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS) signal intensity (actual MDS/control treatment MDS) threshold values of 1.25 (T1 treatment) and 1.35 (T2 treatment), which induced two different drought stress levels. Daily variations in leaf (Y{sub l}eaf) and stem (Y{sub s}tem) water potentials, leaf conductance, net photosynthesis, sap flow (SF) and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Y{sub l}eaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Y{sub s}tem was seen to be a better plant water status indicator than Y{sub l}eaf. The difference between the two values of Y (Y{sub s}tem - Y{sub l}eaf {Delta}{Psi}) was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC) was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees. (Author) 40 refs.

  19. A new metric for measuring condition in large predatory sharks.

    Science.gov (United States)

    Irschick, D J; Hammerschlag, N

    2014-09-01

    A simple metric (span condition analysis; SCA) is presented for quantifying the condition of sharks based on four measurements of body girth relative to body length. Data on 104 live sharks from four species that vary in body form, behaviour and habitat use (Carcharhinus leucas, Carcharhinus limbatus, Ginglymostoma cirratum and Galeocerdo cuvier) are given. Condition shows similar levels of variability among individuals within each species. Carcharhinus leucas showed a positive relationship between condition and body size, whereas the other three species showed no relationship. There was little evidence for strong differences in condition between males and females, although more male sharks are needed for some species (e.g. G. cuvier) to verify this finding. SCA is potentially viable for other large marine or terrestrial animals that are captured live and then released. © 2014 The Fisheries Society of the British Isles.

  20. Switch from sexual to parthenogenetic reproduction in a zebra shark.

    Science.gov (United States)

    Dudgeon, Christine L; Coulton, Laura; Bone, Ren; Ovenden, Jennifer R; Thomas, Severine

    2017-01-16

    Parthenogenesis is a natural form of asexual reproduction in which embryos develop in the absence of fertilisation. Most commonly found in plants and invertebrate organisms, an increasing number of vertebrate species have recently been reported employing this reproductive strategy. Here we use DNA genotyping to report the first demonstration of an intra-individual switch from sexual to parthenogenetic reproduction in a shark species, the zebra shark Stegostoma fasciatum. A co-housed, sexually produced daughter zebra shark also commenced parthenogenetic reproduction at the onset of maturity without any prior mating. The demonstration of parthenogenesis in these two conspecific individuals with different sexual histories provides further support that elasmobranch fishes may flexibly adapt their reproductive strategy to environmental circumstances.

  1. Maternal transfer of organohalogenated compounds in sharks and stingrays.

    Science.gov (United States)

    Weijs, Liesbeth; Briels, Nathalie; Adams, Douglas H; Lepoint, Gilles; Das, Krishna; Blust, Ronny; Covaci, Adrian

    2015-03-15

    Elasmobranchs can bioaccumulate considerable amounts of persistent organic pollutants (POPs) and utilize several reproductive strategies thereby influencing maternal transfer of contaminants. This study provides preliminary data on the POP transfer from pregnant females to offspring of three species (Atlantic stingrays, bonnethead, blacktip sharks) with different reproduction modes (aplacental, placental viviparity). Polychlorinated biphenyl (PCB) levels were generally higher than any other POPs. Stingrays and blacktip shark embryos contained the lowest POP concentrations while bonnetheads and the blacktip adult female had the highest concentrations. Results suggest that POPs are more readily transferred from the mother to the embryo compared to what is transferred to ova in stingrays. Statistically significant differences in levels of selected POPs were found between embryos from the left and right uterus within the same litter as well as between female and male embryos within the same litter for bonnetheads, but not for the blacktip sharks. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. The effect of cold aqueous extract of lemon peel against types of bacteria isolated from the cooling devices Filters

    Directory of Open Access Journals (Sweden)

    Ashraf S. Hassan

    2017-11-01

    Full Text Available The antibacterial effect of citrus peel lemon against the bacterial strains obtained from the filters of air conditioners have been selected based on the presence most in these filters such as Streptococcus, Bacillus spp, Pseudomonas, E coli. agar well diffusion method used to evaluate antibacterial activity of citrus peels water extract. through the results became clear to us that the cold aqueous extract of lemon peel showed a significant effect on the growth of bacterial species through the diameters of inhibition zone that appeared in all concentrations of the extract (125, 250, 500, 1000 mg/ml. Gram-positive bacteria Streptococcus spp were the most affected Where the diameters of inhibition zone (18, 15, 12, 0, 0 mm respectively, while The Gram-negative bacteria E coli least affected. The results obtained in this study indicate that citrus lemon peel can be used in the treatment of diseases caused by organisms for the purposes of the pharmaceutical.

  3. Efficacy Assessment of Lemon Peel Aromatherpy Againts Airborne Bacteria Experimental Study in ICU Room of Sultan Agung Islamic Hospital Semarang

    Directory of Open Access Journals (Sweden)

    Merin Awu Sari

    2012-06-01

    Design and Method: This experimental study used post test only control groups design. The number of airborne bacteria colonies obtained from ICU room of Sultan Agung Islamic Hospital Semarang treated with lemon peel aromatherapy at the concentration of 100 % and the control group (-.The data were analyzed for normality using Shapiro Wilk followed by independent T-test Result: independent inT-test Independent showed a significant differences in the number of bacterial colonies between the treated groups receiving 100% concentration of lemon peel aromatherapy and control group (- (p < 0.045. Conclusion: Aromatherapy extracts of lemon peel has effect on reducing the number of airborne bacteria in the ICU of Sultan Agung Islamic Hospital Semarang (Sains Medika, 4(1:71-77.

  4. Application of Shark Skin Flow Control Techniques to Airflow

    Science.gov (United States)

    Morris, Jackson Alexander

    Due to millions of years of evolution, sharks have evolved to become quick and efficient ocean apex predators. Shark skin is made up of millions of microscopic scales, or denticles, that are approximately 0.2 mm in size. Scales located on the shark's body where separation control is paramount (such as behind the gills or the trailing edge of the pectoral fin) are capable of bristling. These scales are hypothesized to act as a flow control mechanism capable of being passively actuated by reversed flow. It is believed that shark scales are strategically sized to interact with the lower 5% of a boundary layer, where reversed flow occurs at the onset of boundary layer separation. Previous research has shown shark skin to be capable of controlling separation in water. This thesis aims to investigate the same passive flow control techniques in air. To investigate this phenomenon, several sets of microflaps were designed and manufactured with a 3D printer. The microflaps were designed in both 2D (rectangular) and 3D (mirroring shark scale geometry) variants. These microflaps were placed in a low-speed wind tunnel in the lower 5% of the boundary layer. Solid fences and a flat plate diffuser with suction were placed in the tunnel to create different separated flow regions. A hot film probe was used to measure velocity magnitude in the streamwise plane of the separated regions. The results showed that low-speed airflow is capable of bristling objects in the boundary layer. When placed in a region of reverse flow, the microflaps were passively actuated. Microflaps fluctuated between bristled and flat states in reverse flow regions located close to the reattachment zone.

  5. DNA capture reveals transoceanic gene flow in endangered river sharks.

    Science.gov (United States)

    Li, Chenhong; Corrigan, Shannon; Yang, Lei; Straube, Nicolas; Harris, Mark; Hofreiter, Michael; White, William T; Naylor, Gavin J P

    2015-10-27

    For over a hundred years, the "river sharks" of the genus Glyphis were only known from the type specimens of species that had been collected in the 19th century. They were widely considered extinct until populations of Glyphis-like sharks were rediscovered in remote regions of Borneo and Northern Australia at the end of the 20th century. However, the genetic affinities between the newly discovered Glyphis-like populations and the poorly preserved, original museum-type specimens have never been established. Here, we present the first (to our knowledge) fully resolved, complete phylogeny of Glyphis that includes both archival-type specimens and modern material. We used a sensitive DNA hybridization capture method to obtain complete mitochondrial genomes from all of our samples and show that three of the five described river shark species are probably conspecific and widely distributed in Southeast Asia. Furthermore we show that there has been recent gene flow between locations that are separated by large oceanic expanses. Our data strongly suggest marine dispersal in these species, overturning the widely held notion that river sharks are restricted to freshwater. It seems that species in the genus Glyphis are euryhaline with an ecology similar to the bull shark, in which adult individuals live in the ocean while the young grow up in river habitats with reduced predation pressure. Finally, we discovered a previously unidentified species within the genus Glyphis that is deeply divergent from all other lineages, underscoring the current lack of knowledge about the biodiversity and ecology of these mysterious sharks.

  6. Feeding of the megamouth shark (Pisces: Lamniformes: Megachasmidae) predicted by its hyoid arch: a biomechanical approach.

    Science.gov (United States)

    Tomita, Taketeru; Sato, Keiichi; Suda, Kenta; Kawauchi, Junro; Nakaya, Kazuhiro

    2011-05-01

    Studies of the megamouth shark, one of three planktivorous sharks, can provide information about their evolutionary history. Megamouth shark feeding has never been observed in life animals, but two alternative hypotheses on biomechanics suggest either feeding, i.e., ram feeding or suction feeding. In this study, the second moment of area of the ceratohyal cartilages, which is an indicator of the flexural stiffness of the cartilages, is calculated for 21 species of ram- and suction-feeding sharks using computed tomography. The results indicate that suction-feeding sharks have ceratohyal cartilages with a larger second moment of area than ram-feeding sharks. The result also indicates that the ram-suction index, which is an indicator of relative contribution of ram and suction behavior, is also correlated with the second moment of area of the ceratohyal. Considering that large bending stresses are expected to be applied to the ceratohyal cartilage during suction, the larger second moment of area of the ceratohyal of suction-feeding sharks can be interpreted as an adaptation for suction feeding. Based on the small second moment of area of the ceratohyal cartilage of the megamouth shark, the feeding mode of the megamouth shark is considered to be ram feeding, similar to the planktivorous basking shark. From these results, an evolutionary scenario of feeding mechanics of three species of planktivorous sharks can be suggested. In this scenario, the planktivorous whale shark evolved ram feeding from a benthic suction-feeding ancestor. Ram feeding in the planktivorous megamouth shark and the basking shark evolved from ram feeding swimming-type ancestors and that both developed their unique filtering system to capture small-sized prey. Copyright © 2011 Wiley-Liss, Inc.

  7. Quantification of Massive Seasonal Aggregations of Blacktip Sharks (Carcharhinus limbatus) in Southeast Florida.

    Science.gov (United States)

    Kajiura, Stephen M; Tellman, Shari L

    2016-01-01

    Southeast Florida witnesses an enormous seasonal influx of upper trophic level marine predators each year as massive aggregations of migrating blacktip sharks (Carcharhinus limbatus) overwinter in nearshore waters. The narrow shelf and close proximity of the Gulf Stream current to the Palm Beach County shoreline drive tens of thousands of sharks to the shallow, coastal environment. This natural bottleneck provides a unique opportunity to estimate relative abundance. Over a four year period from 2011-2014, an aerial survey was flown approximately biweekly along the length of Palm Beach County. A high definition video camera and digital still camera mounted out of the airplane window provided a continuous record of the belt transect which extended 200 m seaward from the shoreline between Boca Raton Inlet and Jupiter Inlet. The number of sharks within the survey transect was directly counted from the video. Shark abundance peaked in the winter (January-March) with a maximum in 2011 of 12,128 individuals counted within the 75.6 km(-2) belt transect. This resulted in a maximum density of 803.2 sharks km(-2). By the late spring (April-May), shark abundance had sharply declined to 1.1% of its peak, where it remained until spiking again in January of the following year. Shark abundance was inversely correlated with water temperature and large numbers of sharks were found only when water temperatures were less than 25 °C. Shark abundance was also correlated with day of the year but not with barometric pressure. Although shark abundance was not correlated with photoperiod, the departure of the sharks from southeast Florida occurred around the vernal equinox. The shark migration along the United States eastern seaboard corresponds spatially and temporally with the spawning aggregations of various baitfish species. These baseline abundance data can be compared to future studies to determine if shark population size is changing and if sharks are restricting their southward

  8. SHARK-NIR system design analysis overview

    Science.gov (United States)

    Viotto, Valentina; Farinato, Jacopo; Greggio, Davide; Vassallo, Daniele; Carolo, Elena; Baruffolo, Andrea; Bergomi, Maria; Carlotti, Alexis; De Pascale, Marco; D'Orazi, Valentina; Fantinel, Daniela; Magrin, Demetrio; Marafatto, Luca; Mohr, Lars; Ragazzoni, Roberto; Salasnich, Bernardo; Verinaud, Christophe

    2016-08-01

    In this paper, we present an overview of the System Design Analysis carried on for SHARK-NIR, the coronagraphic camera designed to take advantage of the outstanding performance that can be obtained with the FLAO facility at the LBT, in the near infrared regime. Born as a fast-track project, the system now foresees both coronagraphic direct imaging and spectroscopic observing mode, together with a first order wavefront correction tool. The analysis we here report includes several trade-offs for the selection of the baseline design, in terms of optical and mechanical engineering, and the choice of the coronagraphic techniques to be implemented, to satisfy both the main scientific drivers and the technical requirements set at the level of the telescope. Further care has been taken on the possible exploitation of the synergy with other LBT instrumentation, like LBTI. A set of system specifications is then flown down from the upper level requirements to finally ensure the fulfillment of the science drivers. The preliminary performance budgets are presented, both in terms of the main optical planes stability and of the image quality, including the contributions of the main error sources in different observing modes.

  9. Characterization of the 'Xiangshui' lemon transcriptome by de novo assembly to discover genes associated with self-incompatibility.

    Science.gov (United States)

    Zhang, Shuwei; Ding, Feng; He, Xinhua; Luo, Cong; Huang, Guixiang; Hu, Ying

    2015-02-01

    Seedlessness is a desirable character in lemons and other citrus species. Seedless fruit can be induced in many ways, including through self-incompatibility (SI). SI is widely used as an intraspecific reproductive barrier that prevents self-fertilization in flowering plants. Although there have been many studies on SI, its mechanism remains unclear. The 'Xiangshui' lemon is an important seedless cultivar whose seedlessness has been caused by SI. It is essential to identify genes involved in SI in 'Xiangshui' lemon to clarify its molecular mechanism. In this study, candidate genes associated with SI were identified using high-throughput Illumina RNA sequencing (RNA-seq). A total of 61,224 unigenes were obtained (average, 948 bp; N50 of 1,457 bp), among which 47,260 unigenes were annotated by comparison to six public databases (Nr, Nt, Swiss-Prot, KEGG, COG, and GO). Differentially expressed genes were identified by comparing the transcriptomes of no-, self-, and cross-pollinated stigmas with styles of the 'Xiangshui' lemon. Several differentially expressed genes that might be associated with SI were identified, such as those involved in pollen tube growth, programmed cell death, signal transduction, and transcription. NADPH oxidase genes associated with apoptosis were highly upregulated in the self-pollinated transcriptome. The expression pattern of 12 genes was analyzed by quantitative real-time polymerase chain reaction. A putative S-RNase gene was identified that had not been previously associated with self-pollen rejection in lemon or citrus. This study provided a transcriptome dataset for further studies of SI and seedless lemon breeding.

  10. Melanoma in the skin of a nurse shark (Ginglymostoma cirratum).

    Science.gov (United States)

    Waldoch, Jennifer A; Burke, Sandy S; Ramer, Jan C; Garner, Michael M

    2010-12-01

    A female nurse shark, Ginglymostoma cirratum, estimated at 27 yr of age had a 5.5-yr history of a 6-cm black, raised nodular skin lesion located on the right side of the proximal tail. The lesion was diagnosed on biopsy as a slow-growing melanoma of the skin with no vascular invasion. The nurse shark was euthanized for systemic illness approximately 4.5 mo after diagnosis of the dermal melanoma. No evidence of metastasis was found on histopathologic evaluation of the skin and viscera.

  11. Shark-bitten vertebrate coprolites from the Miocene of Maryland

    Science.gov (United States)

    Godfrey, Stephen J.; Smith, Joshua B.

    2010-05-01

    Coprolites (fossilized feces) preserve a wide range of biogenic components, from bacteria and spores to a variety of vertebrate tissues. Two coprolites from the Calvert Cliffs outcrop belt (Miocene-aged Chesapeake Group), MD, USA, preserve shark tooth impressions in the form of partial dental arcades. The specimens are the first known coprolites to preserve vertebrate tooth marks. They provide another example of trace fossils providing evidence of prehistoric animal behaviors that cannot be directly approached through the study of body fossils. Shark behaviors that could account for these impressions include: (1) aborted coprophagy, (2) benthic or nektonic exploration, or (3) predation.

  12. Sustainability evaluation of Sicily's lemon and orange production: an energy, economic and environmental analysis.

    Science.gov (United States)

    Pergola, M; D'Amico, M; Celano, G; Palese, A M; Scuderi, A; Di Vita, G; Pappalardo, G; Inglese, P

    2013-10-15

    The island of Sicily has a long standing tradition in citrus growing. We evaluated the sustainability of orange and lemon orchards, under organic and conventional farming, using an energy, environmental and economic analysis of the whole production cycle by using a life cycle assessment approach. These orchard systems differ only in terms of a few of the inputs used and the duration of the various agricultural operations. The quantity of energy consumption in the production cycle was calculated by multiplying the quantity of inputs used by the energy conversion factors drawn from the literature. The production costs were calculated considering all internal costs, including equipment, materials, wages, and costs of working capital. The performance of the two systems (organic and conventional), was compared over a period of fifty years. The results, based on unit surface area (ha) production, prove the stronger sustainability of the organic over the conventional system, both in terms of energy consumption and environmental impact, especially for lemons. The sustainability of organic systems is mainly due to the use of environmentally friendly crop inputs (fertilizers, not use of synthetic products, etc.). In terms of production costs, the conventional management systems were more expensive, and both systems were heavily influenced by wages. In terms of kg of final product, the organic production system showed better environmental and energy performances. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Fermented Citrus Lemon Reduces Liver Injury Induced by Carbon Tetrachloride in Rats

    Directory of Open Access Journals (Sweden)

    Yi Jinn Lillian Chen

    2018-01-01

    Full Text Available Fermented lemon juice displays a variety of important biological activities, including anti-inflammatory and antioxidant capabilities. The aim of the present study is to investigate hepatic-protective effects of no-sugar-added fermented lemon juice (FLJ for liver inflammation caused by carbon tetrachloride (CCl4 in rats. Rats are divided into six groups: H2O, CCl4 + H2O, CCl4 + silymarin, and CCl4 plus three different FLJ doses by oral administration, respectively. The results show that the contents of plasma ALT and AST, hepatic lipid peroxidation, splenomegaly, and liver water are reduced significantly in rats under FLJ treatment, and pathological examination of liver fibrosis is improved. The reduced hepatic injury by increasing liver soluble protein and glutathione and albumin is observed in FLJ treated groups, and FLJ has comparable efficacies to medicine silymarin in liver therapies. The no-sugar-added FLJ differs from traditional fermentation by adding lots of sugar and prevents any hidden sugar intake while taking it as a complimentary treatment for liver inflammation. The green color and the taste of sourness are both associated with treating and healing the liver based on the five-element theory in traditional Chinese medicine, and the green and sour FLJ may be applied to the ancient theory in preventing hepatic injury accordingly.

  14. The Species and Origin of Shark Fins in Taiwan's Fishing Ports, Markets, and Customs Detention: A DNA Barcoding Analysis.

    Science.gov (United States)

    Chuang, Po-Shun; Hung, Tzu-Chiao; Chang, Hung-An; Huang, Chien-Kang; Shiao, Jen-Chieh

    2016-01-01

    The increasing consumption of shark products, along with the shark's fishing vulnerabilities, has led to the decrease in certain shark populations. In this study we used a DNA barcoding method to identify the species of shark landings at fishing ports, shark fin products in retail stores, and shark fins detained by Taiwan customs. In total we identified 23, 24, and 14 species from 231 fishing landings, 316 fin products, and 113 detained shark fins, respectively. All the three sample sources were dominated by Prionace glauca, which accounted for more than 30% of the collected samples. Over 60% of the species identified in the fin products also appeared in the port landings, suggesting the domestic-dominance of shark fin products in Taiwan. However, international trade also contributes a certain proportion of the fin product markets, as four species identified from the shark fin products are not found in Taiwan's waters, and some domestic-available species were also found in the customs-detained sample. In addition to the species identification, we also found geographical differentiation in the cox1 gene of the common thresher sharks (Alopias vulpinus), the pelagic thresher shark (A. pelagicus), the smooth hammerhead shark (Sphyrna zygaena), and the scalloped hammerhead shark (S. lewini). This result might allow fishing authorities to more effectively trace the origins as well as enforce the management and conservation of these sharks.

  15. The Species and Origin of Shark Fins in Taiwan's Fishing Ports, Markets, and Customs Detention: A DNA Barcoding Analysis.

    Directory of Open Access Journals (Sweden)

    Po-Shun Chuang

    Full Text Available The increasing consumption of shark products, along with the shark's fishing vulnerabilities, has led to the decrease in certain shark populations. In this study we used a DNA barcoding method to identify the species of shark landings at fishing ports, shark fin products in retail stores, and shark fins detained by Taiwan customs. In total we identified 23, 24, and 14 species from 231 fishing landings, 316 fin products, and 113 detained shark fins, respectively. All the three sample sources were dominated by Prionace glauca, which accounted for more than 30% of the collected samples. Over 60% of the species identified in the fin products also appeared in the port landings, suggesting the domestic-dominance of shark fin products in Taiwan. However, international trade also contributes a certain proportion of the fin product markets, as four species identified from the shark fin products are not found in Taiwan's waters, and some domestic-available species were also found in the customs-detained sample. In addition to the species identification, we also found geographical differentiation in the cox1 gene of the common thresher sharks (Alopias vulpinus, the pelagic thresher shark (A. pelagicus, the smooth hammerhead shark (Sphyrna zygaena, and the scalloped hammerhead shark (S. lewini. This result might allow fishing authorities to more effectively trace the origins as well as enforce the management and conservation of these sharks.

  16. Shark teeth as edged weapons: serrated teeth of three species of selachians.

    Science.gov (United States)

    Moyer, Joshua K; Bemis, William E

    2017-02-01

    Prior to European contact, South Pacific islanders used serrated shark teeth as components of tools and weapons. They did this because serrated shark teeth are remarkably effective at slicing through soft tissues. To understand more about the forms and functions of serrated shark teeth, we examined the morphology and histology of tooth serrations in three species: the Tiger Shark (Galeocerdo cuvier), Blue Shark (Prionace glauca), and White Shark (Carcharodon carcharias). We show that there are two basic types of serrations. A primary serration consists of three layers of enameloid with underlying dentine filling the serration's base. All three species studied have primary serrations, although the dentine component differs (orthodentine in Tiger and Blue Sharks; osteodentine in the White Shark). Smaller secondary serrations are found in the Tiger Shark, formed solely by enameloid with no contribution from underlying dentine. Secondary serrations are effectively "serrations within serrations" that allow teeth to cut at different scales. We propose that the cutting edges of Tiger Shark teeth, equipped with serrations at different scales, are linked to a diet that includes large, hard-shelled prey (e.g., sea turtles) as well as smaller, softer prey such as fishes. We discuss other aspects of serration form and function by making analogies to man-made cutting implements, such as knives and saws. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Introduction to Northeast Pacific Shark Biology, Research, and Conservation, Part B.

    Science.gov (United States)

    Larson, Shawn E; Lowry, Dayv

    Sharks are iconic, sometimes apex, predators found in every ocean. Because of their ecological role as predators and concern over the stability of their populations, there has been an increasing amount of work focused on shark conservation around the world in recent decades. The populations of sharks that reside in the Northeast Pacific (NEP) Ocean bordering the west coast of the United States reside in one of the most economically and ecologically important oceanic regions in the world. Volume 78 of Advances in Marine Biology (AMB) is a companion to Volume 77, which focused primarily on NEP shark biodiversity, organismal biology, and ecology. Volume 78 highlights fisheries and the conservation implications of fisheries management; shark population modelling and the conservation impacts of these models given that many life history metrics of NEP sharks necessary to accurately run these models are still unknown; the value of captive sharks to the biology, outreach, and conservation of NEP sharks; and the conservation value of citizen science and shark ecotourism. Together these volumes encapsulate the current state of the knowledge for sharks in the NEP and lay the foundation for protecting, managing, and learning from these species in the face evolving natural conditions and societal opinions. © 2017 Elsevier Ltd All rights reserved.

  18. Utility of mesohabitat features for determining habitat associations of subadult sharks in Georgia’s estuaries

    Science.gov (United States)

    Belcher, C.N.; Jennings, Cecil A.

    2010-01-01

    We examined the affects of selected water quality variables on the presence of subadult sharks in six of nine Georgia estuaries. During 231 longline sets, we captured 415 individuals representing nine species. Atlantic sharpnose shark (Rhizoprionodon terranovae), bonnethead (Sphyrna tiburo), blacktip shark (Carcharhinus limbatus) and sandbar shark (C. plumbeus) comprised 96.1% of the catch. Canonical correlation analysis (CCA) was used to assess environmental influences on the assemblage of the four common species. Results of the CCA indicated Bonnethead Shark and Sandbar Shark were correlated with each other and with a subset of environmental variables. When the species occurred singly, depth was the defining environmental variable; whereas, when the two co-occurred, dissolved oxygen and salinity were the defining variables. Discriminant analyses (DA) were used to assess environmental influences on individual species. Results of the discriminant analyses supported the general CCA findings that the presence of bonnethead and sandbar shark were the only two species that correlated with environmental variables. In addition to depth and dissolved oxygen, turbidity influenced the presence of sandbar shark. The presence of bonnethead shark was influenced primarily by salinity and turbidity. Significant relationships existed for both the CCA and DA analyses; however, environmental variables accounted for shark species among sites.

  19. Quantifying shark distribution patterns and species-habitat associations: implications of marine park zoning.

    Science.gov (United States)

    Espinoza, Mario; Cappo, Mike; Heupel, Michelle R; Tobin, Andrew J; Simpfendorfer, Colin A

    2014-01-01

    Quantifying shark distribution patterns and species-specific habitat associations in response to geographic and environmental drivers is critical to assessing risk of exposure to fishing, habitat degradation, and the effects of climate change. The present study examined shark distribution patterns, species-habitat associations, and marine reserve use with baited remote underwater video stations (BRUVS) along the entire Great Barrier Reef Marine Park (GBRMP) over a ten year period. Overall, 21 species of sharks from five families and two orders were recorded. Grey reef Carcharhinus amblyrhynchos, silvertip C. albimarginatus, tiger Galeocerdo cuvier, and sliteye Loxodon macrorhinus sharks were the most abundant species (>64% of shark abundances). Multivariate regression trees showed that hard coral cover produced the primary split separating shark assemblages. Four indicator species had consistently higher abundances and contributed to explaining most of the differences in shark assemblages: C. amblyrhynchos, C. albimarginatus, G. cuvier, and whitetip reef Triaenodon obesus sharks. Relative distance along the GBRMP had the greatest influence on shark occurrence and species richness, which increased at both ends of the sampling range (southern and northern sites) relative to intermediate latitudes. Hard coral cover and distance across the shelf were also important predictors of shark distribution. The relative abundance of sharks was significantly higher in non-fished sites, highlighting the conservation value and benefits of the GBRMP zoning. However, our results also showed that hard coral cover had a large effect on the abundance of reef-associated shark species, indicating that coral reef health may be important for the success of marine protected areas. Therefore, understanding shark distribution patterns, species-habitat associations, and the drivers responsible for those patterns is essential for developing sound management and conservation approaches.

  20. Biological data from sharks landed within the United Arab Emirates ...

    African Journals Online (AJOL)

    Landing site and market surveys of sharks landed along the Arabian Gulf coast of the United Arab Emirates were undertaken between October 2010 and September 2012 to obtain biological data from this artisanal fishery. Data were collected on the size and sex of 12 482 individuals representing 30 species. Maximum ...

  1. Ferromanganese oxides on sharks' teeth from Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.

    The mineralogy, composition and growth rates of ferromanganese (Fe-Mn) oxides over the sharks' teeth from the Central Indian Ocean Basin are presented. The trends of metal enrichment (Mn, Ni, Cu and Zn) and depletion (Fe and Co), the Mn/Fe ratio...

  2. Some observations on the reproductive biology of the sixgill shark ...

    African Journals Online (AJOL)

    Observations are made of the maturation status of 81 male and 88 female sixgill sharks Hexanchus griseus from southern African waters. Males mature at about 310 cm total length (TL) with the calcification of the terminal cartilage elements of the claspers. Determination of maturity for females was problematic, but most ...

  3. Beyond Jaws : rediscovering the 'lost sharks' of southern Africa ...

    African Journals Online (AJOL)

    Southern Africa has one of the richest and most diverse chondrichthyan faunas in the world, comprising all 13 orders, 49 families, 111 genera and approximately 204 species. This represents nearly 20% of all known chondrichthyans, and includes 117 shark, 79 batoid and 8 chimaera species. A greater diversity of ...

  4. Mortality estimates for juvenile dusky sharks carcharhinus Obscurus ...

    African Journals Online (AJOL)

    A maximum likelihood model is developed, using mark-recapture data, to estimate total and fishing mortality rates for the dusky shark Carcharhinus obscurus in South Africa. The model accounts for tag-shedding, nonreporting of recaptured tags, the multiple release and single recapture nature of the study and the usage of ...

  5. Age, growth and reproductive biology of the blue shark Prionace ...

    African Journals Online (AJOL)

    The age, growth and reproductive biology of the blue shark Prionace glauca from South African waters were assessed using 205 specimens, ranging in total length (TL) from 72 to 313 cm. Greater number of males (120) than females (85) were examined as they were more frequently caught. Age and growth parameters ...

  6. Workshop on SHAring and Reusing architectural Knowledge: (SHARK 2011)

    NARCIS (Netherlands)

    Avgeriou, P.; Lago, P.; Kruchten, P.; Taylor, R.N.; Gall, H.; Medvidovic, N.

    2011-01-01

    Architectural Knowledge (AK) is defined as the integrated representation of the software architecture of a software-intensive system or family of systems along with architectural decisions and their rationale, external influence and the development environment. The SHARK workshop series focuses on

  7. Role of polyols in thermal inactivation of shark ornithine transcarbamoylase

    Czech Academy of Sciences Publication Activity Database

    Bellocco, E.; Lagana, G.; Barreca, D.; Ficarra, S.; Tellone, E.; Magazu, S.; Branca, C.; Kotyk, Arnošt; Galtieri, A.; Leuzzi, U.

    2005-01-01

    Roč. 54, č. 4 (2005), s. 395-402 ISSN 0862-8408 Institutional research plan: CEZ:AV0Z5011922 Keywords : ornithine transcarbamoylase * thermal inactivation * shark enzyme Subject RIV: CE - Biochemistry Impact factor: 1.806, year: 2005

  8. Swimming with Sharks: A Physical Educator's Guide to Effective Crowdsourcing

    Science.gov (United States)

    Bulger, Sean M.; Jones, Emily M.; Katz, Nicole; Shrewsbury, Gentry; Wood, Justin

    2016-01-01

    The reality-competition television series Shark Tank affords up-and-coming entrepreneurs the opportunity to make a formal business presentation to a panel of potential investors. Adopting a similar framework, entrepreneurial teachers have started using web-based collaborative fundraising or crowdsourcing as a tool to build program capacity with…

  9. 77 FR 70551 - Highly Migratory Species; Atlantic Shark Management Measures

    Science.gov (United States)

    2012-11-26

    ... the acceptable biological catch were not considered part of the statement of work for the stock... timeframe, with the 2008 total allowable catch of 220 metric tons (mt) whole weight (ww) (158.3 mt dressed... probability of rebuilding is the level of success for rebuilding of sharks that was established in the 1999...

  10. Ongoing decline of shark populations in the Eastern Red Sea

    KAUST Repository

    Spaet, Julia L.Y.; Nanninga, Gerrit B.; Berumen, Michael L.

    2016-01-01

    compared to other reef systems around the world. Catch per unit effort values of BRUVs on Sudanese reefs on the contrary were within the range of estimates from various locations where sharks are considered common. We argue that decades of heavy fishing

  11. ARM Aerial Facility ArcticShark Unmanned Aerial System

    Science.gov (United States)

    Schmid, B.; Hubbell, M.; Mei, F.; Carroll, P.; Mendoza, A.; Ireland, C.; Lewko, K.

    2017-12-01

    The TigerShark Block 3 XP-AR "ArcticShark" Unmanned Aerial System (UAS), developed and manufactured by Navmar Applied Sciences Corporation (NASC), is a single-prop, 60 hp rotary-engine platform with a wingspan of 6.5 m and Maximum Gross Takeoff Weight of 295 Kg. The ArcticShark is owned by the U.S. Department of Energy (DOE) and has been operated by Pacific Northwest National Laboratory (PNNL) since March 2017. The UAS will serve as an airborne atmospheric research observatory for DOE ARM, and, once fully operational, can be requested through ARM's annual call for proposals. The Arctic Shark is anticipated to measure a wide range of radiative, aerosol, and cloud properties using a variable instrument payload weighing up to 46 Kg. SATCOM-equipped, it is capable of taking measurements up to altitudes of 5.5 Km over ranges of up to 500 Km. The ArcticShark operates at airspeeds of 30 to 40 m/s, making it capable of slow sampling. With a full fuel load, its endurance exceeds 8 hours. The aircraft and its Mobile Operations Center (MOC) have been hardened specifically for operations in colder temperatures.ArcticShark's design facilitates rapid integration of various types of payloads. 2500 W of its 4000 W electrical systems is dedicated to payload servicing. It has an interior payload volume of almost 85 L and four wing-mounted pylons capable of carrying external probes. Its payload bay volume, electrical power, payload capacity, and flight characteristics enable the ArcticShark to accommodate multiple combinations of payloads in numerous configurations. Many instruments will be provided by the ARM Aerial Facility (AAF), but other organizations may eventually propose instrumentation for specific campaigns. AAF-provided measurement capabilities will include the following atmospheric state and thermodynamics: temperature, pressure, winds; gases: H2O and CO2; up- and down-welling broadband infrared and visible radiation; surface temperature; aerosol number concentration

  12. A novel field method to distinguish between cryptic carcharhinid sharks, Australian blacktip shark Carcharhinus tilstoni and common blacktip shark C. limbatus, despite the presence of hybrids.

    Science.gov (United States)

    Johnson, G J; Buckworth, R C; Lee, H; Morgan, J A T; Ovenden, J R; McMahon, C R

    2017-01-01

    Multivariate and machine-learning methods were used to develop field identification techniques for two species of cryptic blacktip shark. From 112 specimens, precaudal vertebrae (PCV) counts and molecular analysis identified 95 Australian blacktip sharks Carcharhinus tilstoni and 17 common blacktip sharks Carcharhinus limbatus. Molecular analysis also revealed 27 of the 112 were C. tilstoni × C. limbatus hybrids, of which 23 had C. tilstoni PCV counts and four had C. limbatus PCV counts. In the absence of further information about hybrid phenotypes, hybrids were assigned as either C. limbatus or C. tilstoni based on PCV counts. Discriminant analysis achieved 80% successful identification, but machine-learning models were better, achieving 100% successful identification, using six key measurements (fork length, caudal-fin peduncle height, interdorsal space, second dorsal-fin height, pelvic-fin length and pelvic-fin midpoint to first dorsal-fin insertion). Furthermore, pelvic-fin markings could be used for identification: C. limbatus has a distinct black mark >3% of the total pelvic-fin area, while C. tilstoni has markings with diffuse edges, or has smaller or no markings. Machine learning and pelvic-fin marking identification methods were field tested achieving 87 and 90% successful identification, respectively. With further refinement, the techniques developed here will form an important part of a multi-faceted approach to identification of C. tilstoni and C. limbatus and have a clear management and conservation application to these commercially important sharks. The methods developed here are broadly applicable and can be used to resolve species identities in many fisheries where cryptic species exist. © 2016 The Fisheries Society of the British Isles.

  13. The experimental vibrational infrared spectrum of lemon peel and simulation of spectral properties of the plant cell wall

    Science.gov (United States)

    Berezin, K. V.; Shagautdinova, I. T.; Chernavina, M. L.; Novoselova, A. V.; Dvoretskii, K. N.; Likhter, A. M.

    2017-09-01

    The experimental vibrational IR spectra of the outer part of lemon peel are recorded in the range of 3800-650 cm-1. The effect of artificial and natural dehydration of the peel on its vibrational spectrum is studied. It is shown that the colored outer layer of lemon peel does not have a noticeable effect on the vibrational spectrum. Upon 28-day storage of a lemon under natural laboratory conditions, only sequential dehydration processes are reflected in the vibrational spectrum of the peel. Within the framework of the theoretical DFT/B3LYP/6-31G(d) method, a model of a plant cell wall is developed consisting of a number of polymeric molecules of dietary fibers like cellulose, hemicellulose, pectin, lignin, some polyphenolic compounds (hesperetin glycoside-flavonoid), and a free water cluster. Using a supermolecular approach, the spectral properties of the wall of a lemon peel cell was simulated, and a detailed theoretical interpretation of the recorded vibrational spectrum is given.

  14. Fractionation of lemon essential oil by solvent extraction: Phase equilibrium for model systems at T = 298.2 K

    International Nuclear Information System (INIS)

    Koshima, Cristina C.; Capellini, Maria C.; Geremias, Ivana M.; Aracava, Keila K.; Gonçalves, Cintia B.; Rodrigues, Christianne E.C.

    2012-01-01

    Highlights: ► Deterpenation of lemon oil by solvent extraction using hydrous ethanol. ► Limonene, γ-terpinene, β-pinene, and citral were used to simulate the oil. ► Citral shows a higher distribution coefficient than the hydrocarbons. ► Terpenic hydrocarbons exhibit very similar phase separation behaviour. ► NRTL and UNIQUAC models provided a good description of the phase equilibrium. - Abstract: The fractioning of lemon essential oil can be performed by liquid–liquid extraction using hydrous ethanol as a solvent. A quaternary mixture composed of limonene, γ-terpinene, β-pinene, and citral was used to simulate lemon essential oil. In this paper, we present (liquid + liquid) equilibrium data that were experimentally determined for systems containing essential oil compounds, ethanol, and water at T = 298.2 K. The experimental data were correlated using the NRTL and UNIQUAC models, and the mean deviations between calculated and experimental data were less than 0.0053 in all systems, indicating the accuracy of these molecular models in describing our systems. The results show that as the water content in the solvent phase increased, the values of the distribution coefficients decreased, regardless of the type of compound studied. However, the oxygenated compound always showed the highest distribution coefficient among the components of the essential oil, thus making deterpenation of the lemon essential oil a feasible process.

  15. Comparison of Glaciological and Gravimetric Glacier Mass Balance Measurements of Taku and Lemon Creek Glaciers, Southeast Alaska

    Science.gov (United States)

    Vogler, K.; McNeil, C.; Bond, M.; Getraer, B.; Huxley-Reicher, B.; McNamara, G.; Reinhardt-Ertman, T.; Silverwood, J.; Kienholz, C.; Beedle, M. J.

    2017-12-01

    Glacier-wide annual mass balances (Ba) have been calculated for Taku (726 km2) and Lemon Creek glaciers (10.2 km2) since 1946 and 1953 respectively. These are the longest mass balance records in North America, and the only Ba time-series available for Southeast Alaska, making them particularly valuable for the global glacier mass balance monitoring network. We compared Ba time-series from Taku and Lemon Creek glaciers to Gravity Recovery and Climate Experiment (GRACE) mascon solutions (1352 and 1353) during the 2004-2015 period to assess how well these gravimetric solutions reflect individual glaciological records. Lemon Creek Glacier is a challenging candidate for this comparison because it is small compared to the 12,100 km2 GRACE mascon solutions. Taku Glacier is equally challenging because its mass balance is stable compared to the negative balances dominating its neighboring glaciers. Challenges notwithstanding, a high correlation between the glaciological and gravimetrically-derived Ba for Taku and Lemon Creek glaciers encourage future use of GRACE to measure glacier mass balance. Additionally, we employed high frequency ground penetrating radar (GPR) to measure the variability of accumulation around glaciological sites to assess uncertainty in our glaciological measurements, and the resulting impact to Ba. Finally, we synthesize this comparison of glaciological and gravimetric mass balance solutions with a discussion of potential sources of error in both methods and their combined utility for measuring regional glacier change during the 21st century.

  16. Effect of lemon verbena supplementation on muscular damage markers, proinflammatory cytokines release and neutrophils' oxidative stress in chronic exercise.

    Science.gov (United States)

    Funes, Lorena; Carrera-Quintanar, Lucrecia; Cerdán-Calero, Manuela; Ferrer, Miguel D; Drobnic, Franchek; Pons, Antoni; Roche, Enrique; Micol, Vicente

    2011-04-01

    Intense exercise is directly related to muscular damage and oxidative stress due to excessive reactive oxygen species (ROS) in both, plasma and white blood cells. Nevertheless, exercise-derived ROS are essential to regulate cellular adaptation to exercise. Studies on antioxidant supplements have provided controversial results. The purpose of this study was to determine the effect of moderate antioxidant supplementation (lemon verbena extract) in healthy male volunteers that followed a 90-min running eccentric exercise protocol for 21 days. Antioxidant enzymes activities and oxidative stress markers were measured in neutrophils. Besides, inflammatory cytokines and muscular damage were determined in whole blood and serum samples, respectively. Intense running exercise for 21 days induced antioxidant response in neutrophils of trained male through the increase of the antioxidant enzymes catalase, glutathione peroxidase and glutathione reductase. Supplementation with moderate levels of an antioxidant lemon verbena extract did not block this cellular adaptive response and also reduced exercise-induced oxidative damage of proteins and lipids in neutrophils and decreased myeloperoxidase activity. Moreover, lemon verbena supplementation maintained or decreased the level of serum transaminases activity indicating a protection of muscular tissue. Exercise induced a decrease of interleukin-6 and interleukin-1β levels after 21 days measured in basal conditions, which was not inhibited by antioxidant supplementation. Therefore, moderate antioxidant supplementation with lemon verbena extract protects neutrophils against oxidative damage, decreases the signs of muscular damage in chronic running exercise without blocking the cellular adaptation to exercise.

  17. The impact of lemon pectin characteristics on TLR activation and T84 intestinal epithelial cell barrier function

    NARCIS (Netherlands)

    Vogt, Leonie M.; Sahasrabudhe, Neha M.; Ramasamy, Uttara; Meyer, Diederick; Pullens, Gerdie; Faas, Marijke M.; Venema, Koen; Schols, Henk A.; de Vos, Paul

    Sufficient dietary fibre intake reduces the risk of several diseases, but the mechanisms linking fibre structure and health effects remain unclear. To analyse the influence of the amount of methyl groups esterified to the backbone, lemon pectins of different degrees of methyl esterification (30, 56,

  18. The impact of lemon pectin characteristics on TLR activation and T84 intestinal epithelial cell barrier function

    NARCIS (Netherlands)

    Vogt, Leonie M.; Sahasrabudhe, Neha M.; Ramasamy, Uttara; Meyer, Diederick; Pullens, Gerdie; Faas, Marijke M.; Venema, Koen; Schols, Henk A.; Vos, de Paul

    2016-01-01

    Sufficient dietary fibre intake reduces the risk of several diseases, but the mechanisms linking fibre structure and health effects remain unclear. To analyse the influence of the amount of methyl groups esterified to the backbone, lemon pectins of different degrees of methyl esterification (30,

  19. Low-methoxyl lemon pectin attenuates inflammatory responses and improves intestinal barrier integrity in caerulein-induced experimental acute pancreatitis

    NARCIS (Netherlands)

    Sun, Yajun; He, Yue; Wang, Fei; Zhang, Hao; de Vos, Paul; Sun, Jia

    Scope: Acute pancreatitis (AP) is a common clinical acute abdominal disease. The intestinal injury associated with AP will aggravate the condition retroactively. This study investigates whether the low-methoxyl pectin (LMP) isolated from lemon could attenuate AP and associated intestinal injury.

  20. Viburnum opulus: Could it be a new alternative, such as lemon juice, to pharmacological therapy in hypocitraturic stone patients?

    Directory of Open Access Journals (Sweden)

    Devrim Tuglu

    2014-12-01

    Full Text Available Objective: Citrate, potassium, and calcium levels in Viburnum opulus (V. opulus and lemon juice were compared to evaluate the usability of V. opulus in mild to moderate level hypocitraturic stone disease. Materials and Methods: V. opulus and lemon fruits were squeezed in a blender and 10 samples of each of 100 ml were prepared. Citrate, calcium, sodium, potassium, magnesium, and pH levels in these samples were examined. Results: Potassium was found to be statistically significantly higher in V. opulus than that in lemon juice (p = 0.006 whereas sodium (p = 0.004 and calcium (p = 0.008 were found to be lower. There was no difference between them in terms of the amount of magnesium and citrate. Concusions: Because V. opulus contains citrate as high as lemon juice does and it is a potassium-rich and calciumand sodium-poor fluid, it can be an alternative to pharmaceutical treatment in mild-to-moderate degree hypocitraturic stone patients. These findings should be supported with clinical studies.

  1. Visual resolution and contrast sensitivity in two benthic sharks.

    Science.gov (United States)

    Ryan, Laura A; Hart, Nathan S; Collin, Shaun P; Hemmi, Jan M

    2016-12-15

    Sharks have long been described as having 'poor' vision. They are cone monochromats and anatomical estimates suggest they have low spatial resolution. However, there are no direct behavioural measurements of spatial resolution or contrast sensitivity. This study estimates contrast sensitivity and spatial resolution of two species of benthic sharks, the Port Jackson shark, Heterodontus portusjacksoni, and the brown-banded bamboo shark, Chiloscyllium punctatum, by recording eye movements in response to optokinetic stimuli. Both species tracked moving low spatial frequency gratings with weak but consistent eye movements. Eye movements ceased at 0.38 cycles per degree, even for high contrasts, suggesting low spatial resolution. However, at lower spatial frequencies, eye movements were elicited by low contrast gratings, 1.3% and 2.9% contrast in H portusjacksoni and C. punctatum, respectively. Contrast sensitivity was higher than in other vertebrates with a similar spatial resolving power, which may reflect an adaptation to the relatively low contrast encountered in aquatic environments. Optokinetic gain was consistently low and neither species stabilised the gratings on their retina. To check whether restraining the animals affected their optokinetic responses, we also analysed eye movements in free-swimming C. punctatum We found no eye movements that could compensate for body rotations, suggesting that vision may pass through phases of stabilisation and blur during swimming. As C. punctatum is a sedentary benthic species, gaze stabilisation during swimming may not be essential. Our results suggest that vision in sharks is not 'poor' as previously suggested, but optimised for contrast detection rather than spatial resolution. © 2016. Published by The Company of Biologists Ltd.

  2. Habitat features influence catch rates of near-shore bull shark (Carcharhinus leucas) in the Queensland Shark Control Program, Australia 1996-2012

    Science.gov (United States)

    Haig, Jodie A.; Lambert, Gwladys I.; Sumpton, Wayne D.; Mayer, David G.; Werry, Jonathan M.

    2018-01-01

    Understanding shark habitat use is vital for informing better ecological management of coastal areas and shark populations. The Queensland Shark Control Program (QSCP) operates over ∼1800 km of Queensland coastline. Between 1996 and 2012, catch, total length and sex were recorded from most of the 1992 bull shark (Carcharhinus leucas) caught on drum lines and gill-nets as part of the QSCP (sex and length was not successfully recorded for all individuals). Gear was set at multiple sites within ten locations. Analysis of monthly catch data resulted in a zero-inflated dataset for the 17 years of records. Five models were trialled for suitability of standardising the bull shark catch per unit effort (CPUE) using available habitat and environmental data. Three separate models for presence-absence and presence-only were run and outputs combined using a delta-lognormal framework for generalized linear and generalized additive models. The delta-lognormal generalized linear model approach resulted in best fit to explain patterns in CPUE. Greater CPUE occurred on drum lines, and greater numbers of bull sharks were caught on both gear types in summer months, with tropical sites, and sites with greater adjacent wetland habitats catching consistently more bull sharks compared to sub-tropical sites. The CPUE data did not support a hypothesis of population decline indicative of coastal overfishing. However, the total length of sharks declined slightly through time for those caught in the tropics; subtropical catches were dominated by females and a large proportion of all bull sharks caught were smaller than the size-at-maturity reported for this species. These factors suggest that growth and sex overfishing of Queensland bull shark populations may be occurring but are not yet detectable in the available data. The data highlight available coastal wetlands, river size, length of coastline and distance to the 50 m depth contour are important for consideration in future whole of

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

    Science.gov (United States)

    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.

  4. Greenland sharks (Somniosus microcephalus scavenge offal from minke (Balaenoptera acutorostrata whaling operations in Svalbard (Norway

    Directory of Open Access Journals (Sweden)

    Lisa-Marie Leclerc

    2011-06-01

    Full Text Available Minke whale (Balaenoptera acutorostrata tissue (mainly blubber was found in the gastrointestinal tracks of Greenland sharks (Somniosus microcephalus collected in Kongsfjorden, Svalbard, Norway. In order to determine whether the sharks were actively hunting the whales, finding naturally dead whales or consuming offal from whaling, we checked the genetic identity of the whale tissue found in the sharks against the DNA register for minke whales taken in Norwegian whaling operations. All of the minke whale samples from the sharks that had DNA of sufficient quality to perform individual identifications were traceable to the whaling DNA register. During whaling operations, the blubber is stripped from the carcass and thrown overboard. The blubber strips float on the surface and are available for surface-feeding predators. This study revealed that Greenland sharks are scavenging this material; additionally, it demonstrates the capacity of this ‘benthic-feeding’ shark to utilize the whole water column for foraging.

  5. Quantitative and qualitative analysis of fluoride and multi elements of shark teeth by PIXE

    International Nuclear Information System (INIS)

    Sakurai, S.; Asakawa, R.; Hirota, F.; Sato, T.; Sera, K.; Itoh, J.

    2008-01-01

    Biomineralization has two types, biologically induced mineralization (BIM) and biologically controlled mineralization (BCM). Shark teeth is a typical representative of BCM. We have measured concentrations of fluorine and multi elements in shark teeth collected in the south of Japan. As a result, it was confirmed that the sample preparation method, which was established for the biological samples, is applicable to the shark teeth samples and the elemental concentration was obtained in good accuracy and reproducibility. Moreover, we clarified that the shark teeth is composed of Fluorapatite by the combination with X-ray Diffraction. Fluorine concentration is found to be 5500 μg/g in the shark teeth. We have 100 samples of Shark teeth and are planning on reporting the findings of a study with larger samples in the near future. (author)

  6. Do White Shark Bites on Surfers Reflect Their Attack Strategies on Pinnipeds?

    Directory of Open Access Journals (Sweden)

    Erich Ritter

    2016-01-01

    Full Text Available The theory of mistaken identity states that sharks, especially white sharks, Carcharodon carcharias, mistake surfers for pinnipeds when looking at them from below and thus bite them erroneously. Photographs of surfer wounds and board damage were interpreted with special emphasis on shark size, wound severity, and extent of damage to a board. These were compared with the concurrent literature on attack strategies of white sharks on pinnipeds and their outcomes. The results show that the majority of damage to surfers and their boards is at best superficial-to-moderate in nature and does not reflect the level of damage needed to immobilize or stun a pinniped. It is further shown that the size distribution of sharks biting surfers differs from that in pinnipeds. The results presented show that the theory of mistaken identity, where white sharks erroneously mistake surfers for pinnipeds, does not hold true and should be rejected.

  7. Green tea, red wine and lemon extracts reduce experimental tumor growth and cancer drug toxicity.

    Science.gov (United States)

    Zaletok, S P; Gulua, L; Wicker, L; Shlyakhovenko, V A; Gogol, S; Orlovsky, O; Karnaushenko, O V; Verbinenko, A; Milinevska, V; Samoylenko, O; Todor, I; Turmanidze, T

    2015-12-01

    To evaluate antitumor effect of plant polyphenol extracts from green tea, red wine lees and/or lemon peel alone and in combination with antitumor drugs on the growth of different transplanted tumors in experimental animals. Green tea extract (GTE) was prepared from green tea infusion. GTE-based composites of red wine (GTRW), lemon peel (GTRWL) and/or NanoGTE as well as corresponding nanocomposites were prepared. The total polyphenolics of the different GTE-based extracts ranged from 18.0% to 21.3%. The effects of GTE-based extracts were studied in sarcoma 180, Ehrlich carcinoma, B16 melanoma, Ca755 mammary carcinoma, P388 leukemia, L1210 leukemia, and Guerin carcinoma (original, cisplatin-resistant and doxorubicin-resistant variants). The extracts were administered as 0.1% solution in drinking water (0.6-1.0 mg by total polyphenolics per mouse per day and 4.0-6.3 mg per rat per day). Tumor growth inhibition (TGI) in mice treated with NanoGTE, cisplatin or cisplatin + NanoGTE was 27%, 55% and 78%, respectively, in Sarcoma 180%, 21%, 45% and 59%, respectively, in Ehrlich carcinoma; and 8%, 13% and 38%, respectively in B16 melanoma. Composites of NanoGTE, red wine, and lemon peel (NanoGTRWL) enhanced the antitumor effects of cyclophosphamide in mice with Ca755 mammary carcinoma. The treatment with combination of NanoGTE and inhibitors of polyamines (PA) synthesis (DFMO + MGBG) resulted in significant TGI of P388 leukemia (up to 71%) and L1210 leukemia. In rats transplanted with Guerin carcinoma (parental strain), treatment with GTRW or GTE alone resulted in 25-28% TGI vs. 55-68% TGI in cisplatin-treated animals. The inhibition observed in the case of combination of GTE or GTRW with cisplatin was additive giving 81-88% TGI. Similar effects were observed when combinations of the cytostatics with GTE (or NanoGTE) were tested against cisplatin- or doxorubicin-resistant Guerin carcinoma. Moreover, the plant extracts lowered side toxicity of the drugs. Treatment with GTE

  8. In Vitro Studies on Phytochemical Content, Antioxidant, Anticancer, Immunomodulatory, and Antigenotoxic Activities of Lemon, Grapefruit, and Mandarin Citrus Peels.

    Science.gov (United States)

    Diab, Kawthar Ae

    2016-01-01

    In recent years, there has been considerable research on recycling of agroindustrial waste for production of bioactive compounds. The food processing industry produces large amounts of citrus peels that may be an inexpensive source of useful agents. The present work aimed to explore the phytochemical content, antioxidant, anticancer, antiproliferation, and antigenotxic activities of lemon, grapefruit, and mandarin peels. Peels were extracted using 98% ethanol and the three crude extracts were assessed for their total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity using DPPH (1, 1diphenyl2picrylhydrazyl). Their cytotoxic and mitogenic proliferation activities were also studied in human leukemia HL60 cells and mouse splenocytes by CCK8 assay. In addition, genotoxic/ antigenotoxic activity was explored in mouse splenocytes using chromosomal aberrations (CAs) assay. Lemon peels had the highest of TPC followed by grapefruit and mandarin. In contrast, mandarin peels contained the highest of TFC followed by lemon and grapefruit peels. Among the extracts, lemon peel possessed the strongest antioxidant activity as indicated by the highest DPPH radical scavenging, the lowest effective concentration 50% (EC50= 42.97 ?g extract/ mL), and the highest Trolox equivalent antioxidant capacity (TEAC=0.157). Mandarin peel exhibited moderate cytotoxic activity (IC50 = 77.8 ?g/mL) against HL60 cells, whereas grapefruit and lemon peels were ineffective antileukemia. Further, citrus peels possessed immunostimulation activity via augmentation of proliferation of mouse splenocytes (Tlymphocytes). Citrus extracts exerted noncytotoxic, and antigenotoxic activities through remarkable reduction of CAs induced by cisplatin in mouse splenocytes for 24 h. The phytochemical constituents of the citrus peels may exert biological activities including anticancer, immunostimulation and antigenotoxic potential.

  9. Shark attacks in Dakar and the Cap Vert Peninsula, Senegal: low incidence despite high occurrence of potentially dangerous species.

    Science.gov (United States)

    Trape, Sébastien

    2008-01-30

    The International Shark Attack File mentions only four unprovoked shark attacks on the coast of West Africa during the period 1828-2004, an area where high concentrations of sharks and 17 species potentially dangerous to man have been observed. To investigate if the frequency of shark attacks could be really low and not just under-reported and whether there are potentially sharks that might attack in the area, a study was carried out in Dakar and the Cap Vert peninsula, Senegal. Personnel of health facilities, administrative services, traditional authorities and groups of fishermen from the region of Dakar were interviewed about the occurrence of shark attacks, and visual censuses were conducted along the coastline to investigate shark communities associated with the coasts of Dakar and the Cap Vert peninsula. Six attacks were documented for the period 1947-2005, including two fatal ones attributed to the tiger shark Galeocerdo cuvieri. All attacks concerned fishermen and only one occurred after 1970. Sharks were observed year round along the coastline in waters 3-15 m depth. Two species potentially dangerous for man, the nurse shark Ginglymostoma cirratum and the blacktip shark Carcharhinus limbatus, represented together 94% of 1,071 sharks enumerated during 1,459 hours of observations. Threatening behaviour from sharks was noted in 12 encounters (1.1%), including 8 encounters with C. limbatus, one with Galeocerdo cuvieri and 3 with unidentified sharks. These findings suggest that the frequency of shark attacks on the coast of West Africa is underestimated. However, they also indicate that the risk is very low despite the abundance of sharks. In Dakar area, most encounters along the coastline with potentially dangerous species do not result in an attack. Compared to other causes of water related deaths, the incidence of shark attack appears negligible, at least one thousand fold lower.

  10. Shark attacks in Dakar and the Cap Vert Peninsula, Senegal: low incidence despite high occurrence of potentially dangerous species.

    Directory of Open Access Journals (Sweden)

    Sébastien Trape

    Full Text Available BACKGROUND: The International Shark Attack File mentions only four unprovoked shark attacks on the coast of West Africa during the period 1828-2004, an area where high concentrations of sharks and 17 species potentially dangerous to man have been observed. To investigate if the frequency of shark attacks could be really low and not just under-reported and whether there are potentially sharks that might attack in the area, a study was carried out in Dakar and the Cap Vert peninsula, Senegal. METHODOLOGY/PRINCIPAL FINDINGS: Personnel of health facilities, administrative services, traditional authorities and groups of fishermen from the region of Dakar were interviewed about the occurrence of shark attacks, and visual censuses were conducted along the coastline to investigate shark communities associated with the coasts of Dakar and the Cap Vert peninsula. Six attacks were documented for the period 1947-2005, including two fatal ones attributed to the tiger shark Galeocerdo cuvieri. All attacks concerned fishermen and only one occurred after 1970. Sharks were observed year round along the coastline in waters 3-15 m depth. Two species potentially dangerous for man, the nurse shark Ginglymostoma cirratum and the blacktip shark Carcharhinus limbatus, represented together 94% of 1,071 sharks enumerated during 1,459 hours of observations. Threatening behaviour from sharks was noted in 12 encounters (1.1%, including 8 encounters with C. limbatus, one with Galeocerdo cuvieri and 3 with unidentified sharks. CONCLUSIONS/SIGNIFICANCE: These findings suggest that the frequency of shark attacks on the coast of West Africa is underestimated. However, they also indicate that the risk is very low despite the abundance of sharks. In Dakar area, most encounters along the coastline with potentially dangerous species do not result in an attack. Compared to other causes of water related deaths, the incidence of shark attack appears negligible, at least one thousand

  11. Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii.

    Science.gov (United States)

    Meyer, Carl G; O'Malley, Joseph M; Papastamatiou, Yannis P; Dale, Jonathan J; Hutchinson, Melanie R; Anderson, James M; Royer, Mark A; Holland, Kim N

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13'17″N 109°52'14″W), in the southern Gulf of California (minimum distance between tag and recapture sites  =  approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

  12. Residency and movement patterns of an apex predatory shark (Galeocerdo cuvier at the Galapagos Marine Reserve.

    Directory of Open Access Journals (Sweden)

    David Acuña-Marrero

    Full Text Available The potential effectiveness of marine protected areas (MPAs as a conservation tool for large sharks has been questioned due to the limited spatial extent of most MPAs in contrast to the complex life history and high mobility of many sharks. Here we evaluated the movement dynamics of a highly migratory apex predatory shark (tiger shark Galeocerdo cuvier at the Galapagos Marine Reserve (GMR. Using data from satellite tracking passive acoustic telemetry, and stereo baited remote underwater video, we estimated residency, activity spaces, site fidelity, distributional abundances and migration patterns from the GMR and in relation to nesting beaches of green sea turtles (Chelonia mydas, a seasonally abundant and predictable prey source for large tiger sharks. Tiger sharks exhibited a high degree of philopatry, with 93% of the total satellite-tracked time across all individuals occurring within the GMR. Large sharks (> 200 cm TL concentrated their movements in front of the two most important green sea turtle-nesting beaches in the GMR, visiting them on a daily basis during nocturnal hours. In contrast, small sharks (< 200 cm TL rarely visited turtle-nesting areas and displayed diurnal presence at a third location where only immature sharks were found. Small and some large individuals remained in the three study areas even outside of the turtle-nesting season. Only two sharks were satellite-tracked outside of the GMR, and following long-distance migrations, both individuals returned to turtle-nesting beaches at the subsequent turtle-nesting season. The spatial patterns of residency and site fidelity of tiger sharks suggest that the presence of a predictable source of prey and suitable habitats might reduce the spatial extent of this large shark that is highly migratory in other parts of its range. This highly philopatric behaviour enhances the potential effectiveness of the GMR for their protection.

  13. Ancient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama

    OpenAIRE

    Pimiento, Catalina; Ehret, Dana J.; MacFadden, Bruce J.; Hubbell, Gordon

    2010-01-01

    BACKGROUND: As we know from modern species, nursery areas are essential shark habitats for vulnerable young. Nurseries are typically highly productive, shallow-water habitats that are characterized by the presence of juveniles and neonates. It has been suggested that in these areas, sharks can find ample food resources and protection from predators. Based on the fossil record, we know that the extinct Carcharocles megalodon was the biggest shark that ever lived. Previous proposed paleo-nurser...

  14. Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin.

    Science.gov (United States)

    Afonso, André S; Garla, Ricardo; Hazin, Fábio H V

    2017-01-01

    Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier) population structure off the oceanic insular system of Fernando de Noronha (FEN) and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175-372 cm in total length (TL) were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured shark-1; SD = 65.6). These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring sharks are able to connect marine trophic webs from the neritic provinces of the eastern and western margins of the Atlantic Ocean across the equatorial basin and that they may experience mortality induced by remote fisheries. All this information is extremely relevant for understanding the energetic balance of marine ecosystems as much as the exposure of this species to fishing pressure in this yet poorly-known region.

  15. 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...

  16. Big catch, little sharks: Insight into Peruvian small-scale longline fisheries

    OpenAIRE

    Doherty, Philip D; Alfaro-Shigueto, Joanna; Hodgson, David J; Mangel, Jeffrey C; Witt, Matthew J; Godley, Brendan J

    2014-01-01

    Shark take, driven by vast demand for meat and fins, is increasing. We set out to gain insights into the impact of small-scale longline fisheries in Peru. Onboard observers were used to document catch from 145 longline fishing trips (1668 fishing days) originating from Ilo, southern Peru. Fishing effort is divided into two seasons: targeting dolphinfish (Coryphaena hippurus; December to February) and sharks (March to November). A total of 16,610 sharks were observed caught, with 11,166 identi...

  17. First record of the blacktip reef shark Carcharhinus melanopterus (Carcharhiniformes: Carcharhinidae from the Tropical Eastern Pacific

    Directory of Open Access Journals (Sweden)

    Andrés López-Garro

    2012-11-01

    Full Text Available The blacktip reef shark Carcharhinus melanopterus, is one of the most common Indo-Pacific reef sharks. On April 29, 2012, a juvenile male blacktip reef shark measuring 89 cm total length (TL, was incidentally caught during a research expedition in Chatham Bay, Isla del Coco National Park, Costa Rica, located in the Tropical Eastern Pacific. This is the first record of the species from Isla del Coco National Park, Costa Rica, and from the Tropical Eastern Pacific.

  18. Structure and dynamics of the shark assemblage off Recife, Northeastern Brazil.

    Science.gov (United States)

    Afonso, André S; Andrade, Humber A; Hazin, Fábio H V

    2014-01-01

    Understanding the ecological factors that regulate elasmobranch abundance in nearshore waters is essential to effectively manage coastal ecosystems and promote conservation. However, little is known about elasmobranch populations in the western South Atlantic Ocean. An 8-year, standardized longline and drumline survey conducted in nearshore waters off Recife, northeastern Brazil, allowed us to describe the shark assemblage and to monitor abundance dynamics using zero-inflated generalized additive models. This region is mostly used by several carcharhinids and one ginglymostomid, but sphyrnids are also present. Blacknose sharks, Carcharhinus acronotus, were mostly mature individuals and declined in abundance throughout the survey, contrasting with nurse sharks, Ginglymostoma cirratum, which proliferated possibly due to this species being prohibited from all harvest since 2004 in this region. Tiger sharks, Galeocerdo cuvier, were mostly juveniles smaller than 200 cm and seem to use nearshore waters off Recife between January and September. No long-term trend in tiger shark abundance was discernible. Spatial distribution was similar in true coastal species (i.e. blacknose and nurse sharks) whereas tiger sharks were most abundant at the middle continental shelf. The sea surface temperature, tidal amplitude, wind direction, water turbidity, and pluviosity were all selected to predict shark abundance off Recife. Interspecific variability in abundance dynamics across spatiotemporal and environmental gradients suggest that the ecological processes regulating shark abundance are generally independent between species, which could add complexity to multi-species fisheries management frameworks. Yet, further research is warranted to ascertain trends at population levels in the South Atlantic Ocean.

  19. Widespread utility of highly informative AFLP molecular markers across divergent shark species.

    Science.gov (United States)

    Zenger, Kyall R; Stow, Adam J; Peddemors, Victor; Briscoe, David A; Harcourt, Robert G

    2006-01-01

    Population numbers of many shark species are declining rapidly around the world. Despite the commercial and conservation significance, little is known on even the most fundamental aspects of their population biology. Data collection that relies on direct observation can be logistically challenging with sharks. Consequently, molecular methods are becoming increasingly important to obtain knowledge that is critical for conservation and management. Here we describe an amplified fragment length polymorphism method that can be applied universally to sharks to identify highly informative genome-wide polymorphisms from 12 primer pairs. We demonstrate the value of our method on 15 divergent shark species within the superorder Galeomorphii, including endangered species which are notorious for low levels of genetic diversity. Both the endangered sand tiger shark (Carcharodon taurus, N = 18) and the great white shark (Carcharodon carcharias, N = 7) displayed relatively high levels of allelic diversity. A total of 59 polymorphic loci (H(e) = 0.373) and 78 polymorphic loci (H(e) = 0.316) were resolved in C. taurus and C. carcharias, respectively. Results from other sharks (e.g., Orectolobus ornatus, Orectolobus sp., and Galeocerdo cuvier) produced remarkably high numbers of polymorphic loci (106, 94, and 86, respectively) from a limited sample size of only 2. A major constraint to obtaining much needed genetic data from sharks is the time-consuming process of developing molecular markers. Here we demonstrate the general utility of a technique that provides large numbers of informative loci in sharks.

  20. Survey sequencing and comparative analysis of the elephant shark (Callorhinchus milii genome.

    Directory of Open Access Journals (Sweden)

    Byrappa Venkatesh

    2007-04-01

    Full Text Available Owing to their phylogenetic position, cartilaginous fishes (sharks, rays, skates, and chimaeras provide a critical reference for our understanding of vertebrate genome evolution. The relatively small genome of the elephant shark, Callorhinchus milii, a chimaera, makes it an attractive model cartilaginous fish genome for whole-genome sequencing and comparative analysis. Here, the authors describe survey sequencing (1.4x coverage and comparative analysis of the elephant shark genome, one of the first cartilaginous fish genomes to be sequenced to this depth. Repetitive sequences, represented mainly by a novel family of short interspersed element-like and long interspersed element-like sequences, account for about 28% of the elephant shark genome. Fragments of approximately 15,000 elephant shark genes reveal specific examples of genes that have been lost differentially during the evolution of tetrapod and teleost fish lineages. Interestingly, the degree of conserved synteny and conserved sequences between the human and elephant shark genomes are higher than that between human and teleost fish genomes. Elephant shark contains putative four Hox clusters indicating that, unlike teleost fish genomes, the elephant shark genome has not experienced an additional whole-genome duplication. These findings underscore the importance of the elephant shark as a critical reference vertebrate genome for comparative analysis of the human and other vertebrate genomes. This study also demonstrates that a survey-sequencing approach can be applied productively for comparative analysis of distantly related vertebrate genomes.

  1. Essential and non-essential element concentrations in two sleeper shark species collected in arctic waters

    Energy Technology Data Exchange (ETDEWEB)

    McMeans, Bailey C. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada); Borga, Katrine [Norwegian Institute for Water Research, P.O. Box 173, Kjelsas, N-0411 Oslo (Norway); Bechtol, William R. [Alaska Department of Fish and Game, Division of Commercial Fisheries, Anchorage, AK 99518-1599 (United States); Higginbotham, David [Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602-2152 (United States); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Avenue, Windsor, ON, N9B 3P4 (Canada)]. E-mail: afisk@uwindsor.ca

    2007-07-15

    A number of elements/metals have increased in arctic biota and are of concern due to their potential toxicity. Most studies on elements in the Arctic have focused on marine mammals and seabirds, but concentrations in the Greenland shark (Somniosus microcephalus) and Pacific sleeper shark (Somniosus pacificus), the only two shark species known to regularly inhabit arctic waters, have never been reported. To address this data gap, concentrations and patterns of 25 elements were analyzed in liver of Greenland sharks collected about Cumberland Sound (n = 24) and Pacific sleeper sharks collected about Prince William Sound (n = 14). Several non-essential elements differed between species/locations, which could suggest geographical exposure differences or ecological (e.g., diet) differences between the species. Certain essential elements also differed between the two sleeper sharks, which may indicate different physiological requirements between these closely related shark species, although information on such relationships are lacking for sharks and fish. - Patterns of essential and non-essential elements provide insight into sleeper shark biology and physiology.

  2. Essential and non-essential element concentrations in two sleeper shark species collected in arctic waters

    International Nuclear Information System (INIS)

    McMeans, Bailey C.; Borga, Katrine; Bechtol, William R.; Higginbotham, David; Fisk, Aaron T.

    2007-01-01

    A number of elements/metals have increased in arctic biota and are of concern due to their potential toxicity. Most studies on elements in the Arctic have focused on marine mammals and seabirds, but concentrations in the Greenland shark (Somniosus microcephalus) and Pacific sleeper shark (Somniosus pacificus), the only two shark species known to regularly inhabit arctic waters, have never been reported. To address this data gap, concentrations and patterns of 25 elements were analyzed in liver of Greenland sharks collected about Cumberland Sound (n = 24) and Pacific sleeper sharks collected about Prince William Sound (n = 14). Several non-essential elements differed between species/locations, which could suggest geographical exposure differences or ecological (e.g., diet) differences between the species. Certain essential elements also differed between the two sleeper sharks, which may indicate different physiological requirements between these closely related shark species, although information on such relationships are lacking for sharks and fish. - Patterns of essential and non-essential elements provide insight into sleeper shark biology and physiology

  3. What the shark immune system can and cannot provide for the expanding design landscape of immunotherapy.

    Science.gov (United States)

    Criscitiello, Michael F

    2014-07-01

    Sharks have successfully lived in marine ecosystems, often atop food chains as apex predators, for nearly one and a half billion years. Throughout this period they have benefitted from an immune system with the same fundamental components found in terrestrial vertebrates like man. Additionally, sharks have some rather extraordinary immune mechanisms which mammals lack. In this review the author briefly orients the reader to sharks, their adaptive immunity, and their important phylogenetic position in comparative immunology. The author also differentiates some of the myths from facts concerning these animals, their cartilage, and cancer. From thereon, the author explores some of the more remarkable capabilities and products of shark lymphocytes. Sharks have an isotype of light chain-less antibodies that are useful tools in molecular biology and are moving towards translational use in the clinic. These special antibodies are just one of the several tricks of shark lymphocyte antigen receptor systems. While shark cartilage has not helped oncology patients, shark immunoglobulins and T cell receptors do offer exciting novel possibilities for immunotherapeutics. Much of the clinical immunology developmental pipeline has turned from traditional vaccines to passively delivered monoclonal antibody-based drugs for targeted depletion, activation, blocking and immunomodulation. The immunogenetic tools of shark lymphocytes, battle-tested since the dawn of our adaptive immune system, are well poised to expand the design landscape for the next generation of immunotherapy products.

  4. Australian and U.S. news media portrayal of sharks and their conservation.

    Science.gov (United States)

    Muter, Bret A; Gore, Meredith L; Gledhill, Katie S; Lamont, Christopher; Huveneers, Charlie

    2013-02-01

    Investigation of the social framing of human-shark interactions may provide useful strategies for integrating social, biological, and ecological knowledge into national and international policy discussions about shark conservation. One way to investigate social opinion and forces related to sharks and their conservation is through the media's coverage of sharks. We conducted a content analysis of 300 shark-related articles published in 20 major Australian and U.S. newspapers from 2000 to 2010. Shark attacks were the emphasis of over half the articles analyzed, and shark conservation was the primary topic of 11% of articles. Significantly more Australian articles than U.S. articles treated shark attacks (χ(2) = 3.862; Australian 58% vs. U.S. 47%) and shark conservation issues (χ(2) = 6.856; Australian 15% vs. U.S. 11%) as the primary article topic and used politicians as the primary risk messenger (i.e., primary person or authority sourced in the article) (χ(2) = 7.493; Australian 8% vs. U.S. 1%). However, significantly more U.S. articles than Australian articles discussed sharks as entertainment (e.g., subjects in movies, books, and television; χ(2) = 15.130; U.S. 6% vs. Australian 1%) and used scientists as the primary risk messenger (χ(2) = 5.333; U.S. 25% vs. Australian 15%). Despite evidence that many shark species are at risk of extinction, we found that most media coverage emphasized the risks sharks pose to people. To the extent that media reflects social opinion, our results highlight problems for shark conservation. We suggest that conservation professionals purposefully and frequently engage with the media to highlight the rarity of shark attacks, discuss preventative measures water users can take to reduce their vulnerability to shark encounters, and discuss conservation issues related to local and threatened species of sharks. When integrated with biological and ecological data, social-science data may help generate a more comprehensive perspective

  5. Acoustic telemetry validates a citizen science approach for monitoring sharks on coral reefs.

    Science.gov (United States)

    Vianna, Gabriel M S; Meekan, Mark G; Bornovski, Tova H; Meeuwig, Jessica J

    2014-01-01

    Citizen science is promoted as a simple and cost-effective alternative to traditional approaches for the monitoring of populations of marine megafauna. However, the reliability of datasets collected by these initiatives often remains poorly quantified. We compared datasets of shark counts collected by professional dive guides with acoustic telemetry data from tagged sharks collected at the same coral reef sites over a period of five years. There was a strong correlation between the number of grey reef sharks (Carcharhinus amblyrhynchos) observed by dive guides and the telemetry data at both daily and monthly intervals, suggesting that variation in relative abundance of sharks was detectable in datasets collected by dive guides in a similar manner to data derived from telemetry at these time scales. There was no correlation between the number or mean depth of sharks recorded by telemetry and the presence of tourist divers, suggesting that the behaviour of sharks was not affected by the presence of divers during our study. Data recorded by dive guides showed that current strength and temperature were important drivers of the relative abundance of sharks at monitored sites. Our study validates the use of datasets of shark abundance collected by professional dive guides in frequently-visited dive sites in Palau, and supports the participation of experienced recreational divers as contributors to long-term monitoring programs of shark populations.

  6. Ultrastructure Organization of Collagen Fibrils and Proteoglycans of Stingray and Shark Corneal Stroma

    Directory of Open Access Journals (Sweden)

    Saud A. Alanazi

    2015-01-01

    Full Text Available We report here the ultrastructural organization of collagen fibrils (CF and proteoglycans (PGs of the corneal stroma of both the stingray and the shark. Three corneas from three stingrays and three corneas from three sharks were processed for electron microscopy. Tissues were embedded in TAAB 031 resin. The corneal stroma of both the stingray and shark consisted of parallel running lamellae of CFs which were decorated with PGs. In the stingray, the mean area of PGs in the posterior stroma was significantly larger than the PGs of the anterior and middle stroma, whereas, in the shark, the mean area of PGs was similar throughout the stroma. The mean area of PGs of the stingray was significantly larger compared to the PGs, mean area of the shark corneal stroma. The CF diameter of the stingray was significantly smaller compared to the CF diameter in the shark. The ultrastructural features of the corneal stroma of both the stingray and the shark were similar to each other except for the CFs and PGs. The PGs in the stingray and shark might be composed of chondroitin sulfate (CS/dermatan sulfate (DS PGs and these PGs with sutures might contribute to the nonswelling properties of the cornea of the stingray and shark.

  7. [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.

  8. A streamlined DNA tool for global identification of heavily exploited coastal shark species (genus Rhizoprionodon.

    Directory of Open Access Journals (Sweden)

    Danillo Pinhal

    Full Text Available Obtaining accurate species-specific landings data is an essential step toward achieving sustainable shark fisheries. Globally distributed sharpnose sharks (genus Rhizoprionodon exhibit life-history characteristics (rapid growth, early maturity, annual reproduction that suggests that they could be fished in a sustainable manner assuming an investment in monitoring, assessment and careful management. However, obtaining species-specific landings data for sharpnose sharks is problematic because they are morphologically very similar to one another. Moreover, sharpnose sharks may also be confused with other small sharks (either small species or juveniles of large species once they are processed (i.e., the head and fins are removed. Here we present a highly streamlined molecular genetics approach based on seven species-specific PCR primers in a multiplex format that can simultaneously discriminate body parts from the seven described sharpnose shark species commonly occurring in coastal fisheries worldwide. The species-specific primers are based on nucleotide sequence differences among species in the nuclear ribosomal internal transcribed spacer 2 locus (ITS2. This approach also distinguishes sharpnose sharks from a wide range of other sharks (52 species and can therefore assist in the regulation of coastal shark fisheries around the world.

  9. Increased and Altered Fragrance of Tobacco Plants after Metabolic Engineering Using Three Monoterpene Synthases from Lemon

    Science.gov (United States)

    Lücker, Joost; Schwab, Wilfried; van Hautum, Bianca; Blaas, Jan; van der Plas, Linus H. W.; Bouwmeester, Harro J.; Verhoeven, Harrie A.

    2004-01-01

    Wild-type tobacco (Nicotiana tabacum) plants emit low levels of terpenoids, particularly from the flowers. By genetic modification of tobacco cv Petit Havana SR1 using three different monoterpene synthases from lemon (Citrus limon L. Burm. f.) and the subsequent combination of these three into one plant by crossings, we show that it is possible to increase the amount and alter the composition of the blend of monoterpenoids produced in tobacco plants. The transgenic tobacco plant line with the three introduced monoterpene synthases is emitting β-pinene, limonene, and γ-terpinene and a number of side products of the introduced monoterpene synthases, from its leaves and flowers, in addition to the terpenoids emitted by wild-type plants. The results show that there is a sufficiently high level of substrate accessible for the introduced enzymes. PMID:14718674

  10. Voluntary Disclosure of Private Information and Unraveling in the Market for Lemons: An Experiment

    Directory of Open Access Journals (Sweden)

    Volker Benndorf

    2018-05-01

    Full Text Available We experimentally analyze a lemons market with a labor-market framing. Sellers are referred to as “workers” and have the possibility to provide “employers” with costly but credible information about their “productivity”. Economic theory suggests that in this setup, unraveling takes place and a number of different types are correctly identified in equilibrium. While we do observe a substantial degree of information disclosure, we also find that unraveling is typically not as complete as predicted by economic theory. The behavior of both workers and employers impedes unraveling in that there is too little disclosure. Workers are generally reluctant to disclose their private information, and employers enforce this behavior by bidding less competitively if workers reveal compared to the case where they conceal information.

  11. Composition of essential oil of lemon thyme (Thymus × citriodorus) at different hydrodistillation times.

    Science.gov (United States)

    Jurevičiūtė, Rūta; Ložienė, Kristina; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio

    2018-02-02

    Distillation time can both to optimise the production and to engineer the composition of essential oil in essential oil bearing plants. Purpose of this study was to evaluate the effect of duration of hydrodistillation on composition of essential oil of Thymus × citriodorus, the natural source of commercially important geraniol and citral, a component with valuable biological properties. Essential oils were isolated by hydrodistillation at different distillation times and analysed by GC/MS analytical methods. Increase in percentage of essential oil during all hydrodistillation time gradient was uneven. Elongation of hydrodistillation time decreased percentages of monoterpenes but increased percentages of sesquiterpenes in essential oil. Results showed that the hydrodistillation of essential oil from lemon thyme longer than 60 min is useless.

  12. Scientific basis for the therapeutic use of Cymbopogon citratus, stapf (Lemon grass

    Directory of Open Access Journals (Sweden)

    Gagan Shah

    2011-01-01

    Full Text Available Cymbopogon citratus, Stapf (Lemon grass is a widely used herb in tropical countries, especially in Southeast Asia. The essential oil of the plant is used in aromatherapy. The compounds identified in Cymbopogon citratus are mainly terpenes, alcohols, ketones, aldehyde and esters. Some of the reported phytoconstituents are essential oils that contain Citral a, Citral b, Nerol Geraniol, Citronellal, Terpinolene, Geranyl acetate, Myrecene and Terpinol Methylheptenone. The plant also contains reported phytoconstituents such as flavonoids and phenolic compounds, which consist of luteolin, isoorientin 2′-O-rhamnoside, quercetin, kaempferol and apiginin. Studies indicate that Cymbopogon citratus possesses various pharmacological activities such as anti-amoebic, antibacterial, antidiarrheal, antifilarial, antifungal and anti-inflammatory properties. Various other effects like antimalarial, antimutagenicity, antimycobacterial, antioxidants, hypoglycemic and neurobehaviorial have also been studied. These results are very encouraging and indicate that this herb should be studied more extensively to confirm these results and reveal other potential therapeutic effects.

  13. Pectins from the albedo of immature lemon fruitlets have high water binding capacity.

    Science.gov (United States)

    Schröder, Roswitha; Clark, Christopher J; Sharrock, Keith; Hallett, Ian C; MacRae, Elspeth A

    2004-04-01

    The white part of citrus peel, the albedo, has a special role in water relations of both fruit and leaves from early on in fruit development. In times of drought, this tissue acts as a water reservoir for juice sacs, seeds and leaves. When water was injected into the albedo, free water was undetectable using magnetic resonance imaging. Microscopy showed tightly packed cells with little intercellular space, and thick cell walls. Cell wall material comprised 21% of the fresh albedo weight, and contained 26.1% galacturonic acid, the main constituent of pectin. From this, we postulated that pectin of the cell wall was responsible for the high water-binding capacity of the immature lemon albedo. Cell wall material was extracted using mild procedures that keep polymers intact, and four pectic fractions were recovered. Of these fractions, the SDS and chelator-soluble fractions showed viscosities ten and twenty times higher than laboratory-grade citrus pectin or the other albedo-derived pectins. The yield of these two pectins represented 28% of the cell walls and 62% of the galacturonic acid content of immature lemon albedo. We concluded that, from viscosity and abundance, these types of pectin account for the high water-binding capacity of this tissue. Compositional analyses showed that the two highly viscous pectic fractions differ in galacturonic acid content, degree of branching and length of side chains from the less viscous albedo-derived pectins. The most striking feature of these highly viscous pectins, however, was their high molecular weight distribution compared to the other pectic fractions.

  14. 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...

  15. Genetic structure of populations of whale sharks among ocean basins and evidence for their historic rise and recent decline

    KAUST Repository

    Vignaud, Thomas M.; Maynard, Jeffrey Allen; Leblois, Raphaë l; Meekan, Mark G.; Vá zquez-Juá rez, Ricardo; Ramí rez-Mací as, Dení ; Pierce, Simon J.; Rowat, David; Berumen, Michael L.; Beeravolu, Champak R.; Baksay, Sandra; Planes, Serge

    2014-01-01

    This study presents genetic evidence that whale sharks, Rhincodon typus, are comprised of at least two populations that rarely mix and is the first to document a population expansion. Relatively high genetic structure is found when comparing sharks

  16. Fine-Scale Movements and Behaviors of Whale Sharks, Rhincodon typus, in a Seasonal Aggregation near Al Lith, Saudi Arabia

    KAUST Repository

    Sun, Lu

    2016-01-01

    . In another dimension, depth use of whale sharks derived from biologgers showed distinct diel patterns. The sharks heavily utilized shallow waters with mixed depth usage consisting of surface swimming and varied types of dives, which explained the data

  17. Effects of species, sex, length, and locality on the mercury content of school shark Galeorhinus australis (Macleay) and gummy shark Mustelus antarcticus Guenther from south-eastern Australian waters

    Energy Technology Data Exchange (ETDEWEB)

    Walker, T.I.

    1976-12-01

    The mercury levels detected in the muscle tissues of sharks ranged from 0.01 to 2.7 ppM wet weight for school shark Galeorhinus australis (Macleay) and from 0.07 to 3.0 ppM for gummy shark Mustelus antarcticus Guenther. Estimates of the mean mercury levels for the 1971 Victorian landed commercial shark catch were found to be 0.90 ppM for the school shark and 0.37 ppM for the gummy shark. The analyses for total mercury determinations were carried out by five independent laboratories. Preliminary analyses carried out by one indicated that most of the mercury in school sharks and about two-thirds of the mercury in gummy sharks was present as methylmercury. The mercury concentrations varied exponentially with shark length. School sharks had statistically significant higher mercury levels than gummy sharks of the same length and for both the medium-sized and large individuals of each species males had significantly higher levels than females. Levels in male gummy sharks were found to be affected by locality.

  18. Temporal and Spatial Distribution of Catches of Tiger Sharks, Galeocerdo cuvier, in the Pelagic Longline Fishery Around the Hawaiian Islands

    OpenAIRE

    Polovina, Jeffrey J.; Lau, Boulderson B.

    1993-01-01

    Thirty-five tiger sharks, Galeocerdo cuvier, have been reported caught in pelagic longline gearfrom 25 to 265 n.mi. off the Hawaiian Archipelago during December 1990-May 1993. Fifteen sharks were caught farther than 50 n.mi. offshore, indicating that tiger sharks do occur well offshore and removed from benthic topography. About 89% of the sharks were caught during October-March, while only 56% of the fishing effort occurred during that period.

  19. The complete mitochondrial genome sequence of the world's largest fish, the whale shark (Rhincodon typus), and its comparison with those of related shark species.

    Science.gov (United States)

    Alam, Md Tauqeer; Petit, Robert A; Read, Timothy D; Dove, Alistair D M

    2014-04-10

    The whale shark (Rhincodon typus) is the largest extant species of fish, belonging to the order Orectolobiformes. It is listed as a "vulnerable" species on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species, which makes it an important species for conservation efforts. We report here the first complete sequence of the mitochondrial genome (mitogenome) of the whale shark obtained by next-generation sequencing methods. The assembled mitogenome is a 16,875 bp circle, comprising of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region. We also performed comparative analysis of the whale shark mitogenome to the available mitogenome sequences of 17 other shark species, four from the order Orectolobiformes, five from Lamniformes and eight from Carcharhiniformes. The nucleotide composition, number and arrangement of the genes in whale shark mitogenome are the same as found in the mitogenomes of the other members of the order Orectolobiformes and its closest orders Lamniformes and Carcharhiniformes, although the whale shark mitogenome had a slightly longer control region. The availability of mitogenome sequence of whale shark will aid studies of molecular systematics, biogeography, genetic differentiation, and conservation genetics in this species. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Effects of Organic and Chemical Fertilizers on Leaf Yield, Essential Oil Content and Composition of Lemon Verbena (Lippia citriodora Kunth

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Ebadi

    2017-02-01

    Full Text Available Introduction: Organic fertilizers with beneficial effects on soil structure and nutrient availability help maintain yield and quality, and they are less costly than synthetic fertilizers. Vermicompost and vermiwash are two organic fertilizers that they contain a biologically active mixture of bacteria, enzymes and phytohormones, also these organic fertilizers can supply the nutritional needs of plants. Lemon verbena (Lippia citriodora Kunth, Verbenaceae is an evergreen perennial aromatic plant. The lemon-scented essential oil from the lemon verbena has been widely used for its digestive, relaxing, antimalarial and lemony flavor properties. In order to decrease the use of chemical fertilizers for reduction of environmental pollution, this research was undertaken to determine effects of vermicompost and vermiwash in comparison with chemical fertilizer on leaf yield, essential oil content and composition of lemon verbena. Materials and Methods: A pot experiment based on a completely randomized design with six treatments and three replications on Lemon verbena was carried out in the experimental greenhouse of the Department of Horticulture Sciences, Tarbiat Modares University, 2012. Treatments consisted of 10, 20 and 30 % by volume of vermicompost and vermiwash (with an addition to irrigation in three steps, including: two weeks after the establishment of plants in pots, the appearing of branches and three weeks before harvest, complete fertilizer and control without any fertilizer. Each replication contained six pots and each pot contained one plant of Lemon verbena provided from Institute of Medicinal Plants, Karaj, therefore 108 pots were used in this experiment. The pots were filled up by a mixture contained 3/5 soil and 2/5 sand (v/v. After three months, plant aerial parts were harvested concomitantly at starting of the flowering stage. Aerial parts were dried at room temperature for 72 hours and dry weights of dried branches and leaves were

  1. Determining Correlation between Shark Location and Atmospheric Wind and Thermal Parameters.

    Science.gov (United States)

    Merchant, J.

    2017-12-01

    Millions of people visit the nation's shorelines every summer. As recreational use of the ocean increases across the country, so too does the risk of shark attacks on people. According to George H. Burgess, curator for the International Shark Attack File and the Florida Program for Shark Research "The number of shark-human interactions occurring in a given year is directly correlated with the amount of time humans spend in the sea. As world population continues its upsurge and interest in aquatic recreation concurrently rises, we realistically should expect increases in the number of shark attacks and other aquatic recreation-related injuries". Burgess' analysis released in February of 2016, states "2015 yearly total of 98 unprovoked attacks (worldwide) was the highest on record" until 2016. Adding to the previous record number of global shark/human interactions in 2015 were 10 confirmed cases of people bitten by sharks off the shores of North Carolina and South Carolina over a five week period in June and July of 2015. The unusually high amount of attacks within close proximity over a short period of time garnered significant media attention nationwide. Preliminary data resulting from the analysis of these 2015 shark attacks and separate acoustic shark location data from Dr. Gregory Skomal's (Program Manager, Senior Marine Fisheries Biologist for the state of Massachusetts) ongoing research across Cape Code do indicate a correlation between environmental and biological factors leading up to human/shark interactions. Not only will these preliminary findings be presented, but a full description of how the use of higher resolution remote sensing and in-situ surface wind and thermal measurements would improve real time detection and prediction of these dangerous conditions, up to hours in advance, mitigating human risk and interaction with shark.

  2. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the coral sea

    KAUST Repository

    Werry, Jonathan M.

    2014-01-08

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  3. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the coral sea

    KAUST Repository

    Werry, Jonathan M.; Planes, Serge; Berumen, Michael L.; Lee, Kate A.; Braun, Camrin D.; Clua, Eric

    2014-01-01

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  4. Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus).

    Science.gov (United States)

    McMeans, Bailey C; Arts, Michael T; Fisk, Aaron T

    2015-03-15

    Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log10THg increased significantly with δ(15)N and trophic position from invertebrates (0.01 ± 0.01 μg · g(-1) [113 ± 1 ng · g(-1)] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg · g(-1)). The slope of the log10THg vs. δ(15)N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the Coral Sea.

    Science.gov (United States)

    Werry, Jonathan M; Planes, Serge; Berumen, Michael L; Lee, Kate A; Braun, Camrin D; Clua, Eric

    2014-01-01

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km³. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  6. The Shark Random Swim - (Lévy Flight with Memory)

    Science.gov (United States)

    Businger, Silvia

    2018-05-01

    The Elephant Random Walk (ERW), first introduced by Schütz and Trimper (Phys Rev E 70:045101, 2004), is a one-dimensional simple random walk on Z having a memory about the whole past. We study the Shark Random Swim, a random walk with memory about the whole past, whose steps are α -stable distributed with α \\in (0,2] . Our aim in this work is to study the impact of the heavy tailed step distributions on the asymptotic behavior of the random walk. We shall see that, as for the ERW, the asymptotic behavior of the Shark Random Swim depends on its memory parameter p, and that a phase transition can be observed at the critical value p=1/α.

  7. 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...

  8. 78 FR 36149 - Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation Act of 2010; Correction

    Science.gov (United States)

    2013-06-17

    .... 111014628-3329-01] RIN 0648-BB54 Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation.... SUMMARY: NMFS published a proposed rule on May 2, 2013, to implement provisions of the Shark Conservation Act of 2010 (SCA) that prohibit any person from removing any of the fins of a shark at sea, possessing...

  9. 77 FR 39648 - Atlantic Highly Migratory Species; Commercial Gulf of Mexico Non-Sandbar Large Coastal Shark Fishery

    Science.gov (United States)

    2012-07-05

    ... Large Coastal Shark Fishery AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and... commercial fishery for non-sandbar large coastal sharks (LCS) in the Gulf of Mexico region. This action is.... SUPPLEMENTARY INFORMATION: The Atlantic shark fisheries are managed under the 2006 Consolidated Atlantic Highly...

  10. 78 FR 40687 - Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation Act of 2010; Extension...

    Science.gov (United States)

    2013-07-08

    .... 111014628-3329-01] RIN 0648-BB54 Magnuson-Stevens Act Provisions; Implementation of the Shark Conservation... period. SUMMARY: NMFS published a proposed rule on May 2, 2013, to implement provisions of the Shark Conservation Act of 2010 (SCA) that prohibit any person from removing any of the fins of a shark at sea...

  11. 76 FR 61092 - Stock Assessment Reports for Dusky, Sandbar, and Blacknose Sharks in the U.S. Atlantic and Gulf...

    Science.gov (United States)

    2011-10-03

    ... Assessment Reports for Dusky, Sandbar, and Blacknose Sharks in the U.S. Atlantic and Gulf of Mexico AGENCY... reports for dusky, sandbar, and blacknose sharks in the Atlantic and Gulf of Mexico. The reports summarize... sharks should be sent to Peter Cooper, Highly Migratory Species Management Division (F/SF1), National...

  12. 76 FR 53840 - Fisheries of the Exclusive Economic Zone Off Alaska; Other Rockfish, Other Flatfish, Sharks, and...

    Science.gov (United States)

    2011-08-30

    ... Flatfish, Sharks, and Skates in the Bering Sea and Aleutian Islands Management Area AGENCY: National Marine...-specified reserve to the initial total allowable catch of other rockfish, other flatfish, sharks, and skates..., BSAI other flatfish, BSAI sharks, and BSAI skates was established as 425 metric tons (mt), 2,550 mt, 43...

  13. 76 FR 59924 - Fisheries of the Exclusive Economic Zone Off Alaska; Sharks in the Bering Sea and Aleutian...

    Science.gov (United States)

    2011-09-28

    .... 101126521-0640-2] RIN 0648-XA733 Fisheries of the Exclusive Economic Zone Off Alaska; Sharks in the Bering... prohibiting retention of sharks in the Bering Sea and Aleutian Islands management area (BSAI). This action is necessary because the 2011 total allowable catch (TAC) of sharks in the BSAI has been reached. DATES...

  14. 78 FR 57097 - Fisheries of the Exclusive Economic Zone Off Alaska; Sharks in the Bering Sea and Aleutian...

    Science.gov (United States)

    2013-09-17

    .... 121018563-3418-02] RIN 0648-XC872 Fisheries of the Exclusive Economic Zone Off Alaska; Sharks in the Bering... prohibiting retention of sharks in the Bering Sea and Aleutian Islands management area (BSAI). This action is necessary because the 2013 total allowable catch (TAC) of sharks in the BSAI has been reached. DATES...

  15. DNA capture reveals transoceanic gene flow in endangered river sharks

    OpenAIRE

    Li, Chenhong; Corrigan, Shannon; Yang, Lei; Straube, Nicolas; Harris, Mark; Hofreiter, Michael; White, William T.; Naylor, Gavin J. P.

    2015-01-01

    The river sharks of the genus Glyphis, widely feared as man-eaters throughout India, remain very poorly known to science. The group constitutes five described species, all of which are considered highly endangered and restricted to freshwater systems in Australasia and Southeast Asia. DNA sequence data derived from 19th-century dried museum material augmented with contemporary samples indicates that only three of the five currently described species are valid; that there is a genetically dist...

  16. Algae Reefs in Shark Bay, Western Australia, Australia

    Science.gov (United States)

    1990-01-01

    Numerous algae reefs are seen in Shark Bay, Western Australia, Australia (26.0S, 113.5E) especially in the southern portions of the bay. The south end is more saline because tidal flow in and out of the bay is restricted by sediment deposited at the north and central end of the bay opposite the mouth of the Wooramel River. This extremely arid region produces little sediment runoff so that the waters are very clear, saline and rich in algae.

  17. Functional morphology of the radialis muscle in shark tails.

    Science.gov (United States)

    Flammang, Brooke E

    2010-03-01

    The functional morphology of intrinsic caudal musculature in sharks has not been studied previously, though the kinematics and function of body musculature have been the focus of a great deal of research. In the tail, ventral to the axial myomeres, there is a thin strip of red muscle with fibers angled dorsoposteriorly, known as the radialis. This research gives the first anatomical description of the radialis muscle in sharks, and addresses the hypothesis that the radialis muscle provides postural stiffening in the tail of live swimming sharks. The radialis muscle fibers insert onto the deepest layers of the stratum compactum, the more superior layers of which are orthogonally arrayed and connect to the epidermis. The two deepest layers of the stratum compactum insert onto the proximal ends of the ceratotrichia of the caudal fin. This anatomical arrangement exists in sharks and is modified in rays, but was not found in skates or chimaeras. Electromyography of the caudal muscles of dogfish swimming steadily at 0.25 and 0.5 body lengths per second (Ls(-1)) exhibited a pattern of anterior to posterior activation of the radialis muscle, followed by activation of red axial muscle in the more anteriorly located ipsilateral myomeres of the caudal peduncle; at 0.75 L s(-1), only the anterior portion of the radialis and white axial muscle of the contralateral peduncular myomeres were active. Activity of the radialis muscle occurred during periods of the greatest drag incurred by the tail during the tail beat and preceded the activity of more anteriorly located axial myomeres. This nonconformity to the typical anterior to posterior wave of muscle activation in fish swimming, in combination with anatomical positioning of the radialis muscles and stratum compactum, suggests that radialis activity may have a postural function to stiffen the fin, and does not function as a typical myotomal muscle.

  18. The V-SHARK high contrast imager at LBT

    Science.gov (United States)

    Pedichini, F.; Ambrosino, F.; Centrone, M.; Farinato, J.; Li Causi, G.; Pinna, E.; Puglisi, A.; Stangalini, M.; Testa, V.

    2016-08-01

    In the framework of the SHARK project the visible channel is a novel instrument synergic to the NIR channel and exploiting the performances of the LBT XAO at visible wavelengths. The status of the project is presented together with the design study of this innovative instrument optimized for high contrast imaging by means of high frame rate. Its expected results will be presented comparing the simulations with the real data of the "Forerunner" experiment taken at 630nm.

  19. 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.

  20. Ecological drivers of shark distributions along a tropical coastline.

    Directory of Open Access Journals (Sweden)

    Peter M Yates

    Full Text Available As coastal species experience increasing anthropogenic pressures there is a growing need to characterise the ecological drivers of their abundance and habitat use, and understand how they may respond to changes in their environment. Accordingly, fishery-independent surveys were undertaken to investigate shark abundance along approximately 400 km of the tropical east coast of Australia. Generalised linear models were used to identify ecological drivers of the abundance of immature blacktip Carcharhinus tilstoni/Carcharhinus limbatus, pigeye Carcharhinus amboinensis, and scalloped hammerhead Sphyrna lewini sharks. Results indicated general and species-specific patterns in abundance that were characterised by a range of abiotic and biotic variables. Relationships with turbidity and salinity were similar across multiple species, highlighting the importance of these variables in the functioning of communal shark nurseries. In particular, turbid environments were especially important for all species at typical oceanic salinities. Mangrove proximity, depth, and water temperature were also important; however, their influence varied between species. Ecological drivers may promote spatial diversity in habitat use along environmentally heterogeneous coastlines and may therefore have important implications for population resilience.

  1. Ecological drivers of shark distributions along a tropical coastline.

    Science.gov (United States)

    Yates, Peter M; Heupel, Michelle R; Tobin, Andrew J; Simpfendorfer, Colin A

    2015-01-01

    As coastal species experience increasing anthropogenic pressures there is a growing need to characterise the ecological drivers of their abundance and habitat use, and understand how they may respond to changes in their environment. Accordingly, fishery-independent surveys were undertaken to investigate shark abundance along approximately 400 km of the tropical east coast of Australia. Generalised linear models were used to identify ecological drivers of the abundance of immature blacktip Carcharhinus tilstoni/Carcharhinus limbatus, pigeye Carcharhinus amboinensis, and scalloped hammerhead Sphyrna lewini sharks. Results indicated general and species-specific patterns in abundance that were characterised by a range of abiotic and biotic variables. Relationships with turbidity and salinity were similar across multiple species, highlighting the importance of these variables in the functioning of communal shark nurseries. In particular, turbid environments were especially important for all species at typical oceanic salinities. Mangrove proximity, depth, and water temperature were also important; however, their influence varied between species. Ecological drivers may promote spatial diversity in habitat use along environmentally heterogeneous coastlines and may therefore have important implications for population resilience.

  2. Effect of yogurt and pH equivalent lemon juice on salivary flow rate in healthy volunteers - An experimental crossover study.

    Science.gov (United States)

    Murugesh, Jeevitha; Annigeri, Rajeshwari G; Raheel, Syed Ahmed; Azzeghaiby, Saleh; Alshehri, Mohammad; Kujan, Omar

    2015-12-01

    Xerostomia is a common clinical problem, and different medications have been tried in its management. In the present study, routine dietary products are used to assess their effect on salivary flow. To assess the efficacy of yogurt and lemon juice on increase in salivation and its comparison with that of unstimulated saliva. A total of 40 volunteers (aged 19-48) were selected. The pH of yogurt was calculated, and equivalent pH lemon juice was prepared. First, normal resting saliva was collected as baseline followed by every 1 min for 5 min. Patients were given lemon juice or yogurt and then crossed over to the other group to assess the impact of the stimulants on salivary flow from 1 to 5 min. The results were analyzed statistically. Comparisons between baseline saliva secretion and that by yogurt and lemon juice (using the ANOVA test) showed that there was a significant increase after treatment at the end of the experiment for both yogurt and lemon juice. However, yogurt showed a significant increase in saliva secretion compared to baseline than lemon juice. Our findings suggest that yogurt is a potential candidate for the treatment of dry mouth.

  3. The immunomodulatory effects of shark cartilage on the mouse and human immune system

    Directory of Open Access Journals (Sweden)

    ali Sheikhian

    2007-01-01

    Materials and methods: In an experimental study, the effects of different doses of shark cartilage on humoral (antibody titer immune response against sheep red blood cells (SRBC, were measured in mouse. In addition, we evaluated the modulatory effects of the shark cartilage on the natural killer (NK activity of the peritoneal cells of mouse against a tumor cell line called K562, according to the standard methods. The proliferative response of the human peripheral blood mononuclear cells was measured under the influence of shark cartilage. Results: Pure shark cartilage enhanced antibody response against SRBC in vivo. The hemagglutination titer which was 1/147 in the control group (injected with hen cartilage, increased to 1/1355 in the test group. The optimal dose was 100 mg/ml. both type of cartilage had blastogenic effect on peripheral blood mononuclear cells (the blastogenic index was 6.7 and 4.9 for impure shark cartilage and hen cartilage, respectively. NK activity was inhibited completely by pure shark cartilage (the amount of the killing activity of the effector peritoneal cells for the control and test groups against target cells was 25.9% and 5.5% respectively. Conclusion: Shark cartilage has a potent immunomodulatory effect on the specific immune mechanisms and some inhibitory effects on the innate immune mechanisms such as NC activity. Since the specific immunity has a more pivotal role against tumor formation, shark cartilage can be used as a cancer immunotherapeutic.

  4. Whale sharks target dense prey patches of sergestid shrimp off Tanzania

    KAUST Repository

    Rohner, C. A.; Armstrong, A. J.; Pierce, S. J.; Prebble, C. E. M.; Cagua, E. F.; Cochran, J. E. M.; Berumen, Michael L.; Richardson, A. J.

    2015-01-01

    Large planktivores require high-density prey patches to make feeding energetically viable. This is a major challenge for species living in tropical and subtropical seas, such as whale sharks Rhincodon typus. Here, we characterize zooplankton biomass, size structure and taxonomic composition from whale shark feeding events and background samples at Mafia Island, Tanzania. The majority of whale sharks were feeding (73%, 380 of 524 observations), with the most common behaviour being active surface feeding (87%). We used 20 samples collected from immediately adjacent to feeding sharks and an additional 202 background samples for comparison to show that plankton biomass was ∼10 times higher in patches where whale sharks were feeding (25 vs. 2.6 mg m-3). Taxonomic analyses of samples showed that the large sergestid Lucifer hanseni (∼10 mm) dominated while sharks were feeding, accounting for ∼50% of identified items, while copepods (<2 mm) dominated background samples. The size structure was skewed towards larger animals representative of L.hanseni in feeding samples. Thus, whale sharks at Mafia Island target patches of dense, large, zooplankton dominated by sergestids. Large planktivores, such as whale sharks, which generally inhabit warm oligotrophic waters, aggregate in areas where they can feed on dense prey to obtain sufficient energy. © 2015 © The Author 2015. Published by Oxford University Press. All rights reserved.

  5. 77 FR 75896 - Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2012-12-26

    ... the non-sandbar large coastal shark quotas and retention limits in 2013 and asked for the reasoning... geographical distribution of non-sandbar large coastal shark landings in the Atlantic throughout the season... the 2006 Consolidated HMS FMP on EFH, we reviewed the geographical range of all HMS and analyzed the...

  6. 78 FR 70500 - Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing Seasons

    Science.gov (United States)

    2013-11-26

    ...- tourism when proposing shark fishing season opening dates. While shark aggregations may benefit eco-tourism, this factor is not one of the specific criteria NMFS uses to establish opening dates. Rather... the religious holiday of Lent and a closure for the fishery on July 1 before the State of Louisiana re...

  7. A first description of the artisanal shark fishery in northern Madagascar

    African Journals Online (AJOL)

    In the past two decades, small, targeted artisanal shark fisheries have developed in the extreme north of Madagascar, largely in response to the shark fin trade. Few studies have been undertaken to assess the biological characteristics and impact of these fisheries. Here, we developed a profile of the fishery in the region of ...

  8. Sharks caught in the protective gill nets off KwaZulu-Natal, South ...

    African Journals Online (AJOL)

    Between 1980 and 2001, a total of 661 African angel sharks Squatina africana was caught in the protective nets off KwaZulu-Natal, South Africa. The mean annual catch was 30 sharks (range = 11–69, SD = 12.4), with no trend in catch rate over the study period. Individuals were caught throughout the year and through ...

  9. Sharks caught in the protective gill nets off KwaZulu-Natal, South ...

    African Journals Online (AJOL)

    Between 1978 and 1998, a total of 3 385 scalloped hammerhead sharks Sphyrna lewini was caught in the protective nets off KwaZulu-Natal. The mean annual catch was 166 sharks (range 60–279). There was a significant decrease in catch rate with time, but the relationship with the population size in KwaZulu-Natal waters ...

  10. Seasonal variability of bull and tiger shark presence on the west ...

    African Journals Online (AJOL)

    A fisheries-independent survey using longlines and drumlines, and an acoustic telemetry study, revealed that bull sharks Carcharhinus leucas and tiger sharks Galeocerdo cuvier occur throughout the year off the west coast of Reunion Island. The research, which commenced in 2011, was conducted in response to an ...

  11. Ecological impact of the end-Cretaceous extinction on lamniform sharks.

    Directory of Open Access Journals (Sweden)

    Rachel A Belben

    Full Text Available Lamniform sharks are apex marine predators undergoing dramatic local and regional decline worldwide, with consequences for marine ecosystems that are difficult to predict. Through their long history, lamniform sharks have faced widespread extinction, and understanding those 'natural experiments' may help constrain predictions, placing the current crisis in evolutionary context. Here we show, using novel morphometric analyses of fossil shark teeth, that the end-Cretaceous extinction of many sharks had major ecological consequences. Post-extinction ecosystems supported lower diversity and disparity of lamniforms, and were dominated by significantly smaller sharks with slimmer, smoother and less robust teeth. Tooth shape is intimately associated with ecology, feeding and prey type, and by integrating data from extant sharks we show that latest Cretaceous sharks occupied similar niches to modern lamniforms, implying similar ecosystem structure and function. By comparison, species in the depauperate post-extinction community occupied niches most similar to those of juvenile sand tigers (Carcharias taurus. Our data show that quantitative tooth morphometrics can distinguish lamniform sharks due to dietary differences, providing critical insights into ecological consequences of past extinction episodes.

  12. First visual record of a living basking shark Cetorhinus maximus in the Caribbean Sea

    NARCIS (Netherlands)

    Geelhoed, S.C.V.; Janinhoff, N.; Verdaat, J.P.

    2016-01-01

    The occurrence of basking sharks in the Caribbean Sea is only recently documented by satellite tagging studies, which show that some individuals migrate through the region en route from waters off the east coast of the USA to waters off northeastern South-America. The observation of a basking shark

  13. Children's Perceptions of Sharks and Understanding of Its Ecological Significance for Educational Implications

    Science.gov (United States)

    Tsoi, Kwok Ho

    2011-01-01

    Global shark populations are seriously declining and many species are now threatened by anthropogenic stresses. Their extinction would cause devastating consequences to the marine biodiversity and ecosystems. However some children describe the sharks as bad guys, "we should kill them all!" Such children's view motivates my study…

  14. Whale sharks target dense prey patches of sergestid shrimp off Tanzania

    KAUST Repository

    Rohner, C. A.

    2015-03-17

    Large planktivores require high-density prey patches to make feeding energetically viable. This is a major challenge for species living in tropical and subtropical seas, such as whale sharks Rhincodon typus. Here, we characterize zooplankton biomass, size structure and taxonomic composition from whale shark feeding events and background samples at Mafia Island, Tanzania. The majority of whale sharks were feeding (73%, 380 of 524 observations), with the most common behaviour being active surface feeding (87%). We used 20 samples collected from immediately adjacent to feeding sharks and an additional 202 background samples for comparison to show that plankton biomass was ∼10 times higher in patches where whale sharks were feeding (25 vs. 2.6 mg m-3). Taxonomic analyses of samples showed that the large sergestid Lucifer hanseni (∼10 mm) dominated while sharks were feeding, accounting for ∼50% of identified items, while copepods (<2 mm) dominated background samples. The size structure was skewed towards larger animals representative of L.hanseni in feeding samples. Thus, whale sharks at Mafia Island target patches of dense, large, zooplankton dominated by sergestids. Large planktivores, such as whale sharks, which generally inhabit warm oligotrophic waters, aggregate in areas where they can feed on dense prey to obtain sufficient energy. © 2015 © The Author 2015. Published by Oxford University Press. All rights reserved.

  15. 75 FR 250 - Atlantic Highly Migratory Species; Atlantic Commercial Shark Management Measures

    Science.gov (United States)

    2010-01-05

    ... January 1, included: increased economic stability for Gulf of Mexico fishermen, increased market prices... helpful given the current economic situation in the country. Having the shark fishery open year round... shipping shark products in January, along with any other fish products, to other markets for economic...

  16. Observations on the whale shark (Rhincodon typus) in the Dutch Caribbean

    NARCIS (Netherlands)

    Debrot, A.O.; Leon, R.; Esteban, N.; Meesters, H.W.G.

    2013-01-01

    Records of whale sharks in the Caribbean are relatively sparse. Here we document 24 records of whale sharks (Rhincodon typus Smith 1882) for the Dutch Caribbean, four for the windward islands of Saba, St. Eustatius and St. Maarten, and twenty for the southern Caribbean leeward islands of Aruba,

  17. Age-related polychlorinated biphenyl dynamics in immature bull sharks (Carcharhinus leucas).

    Science.gov (United States)

    Olin, Jill A; Beaudry, Marina; Fisk, Aaron T; Paterson, Gordon

    2014-01-01

    Polychlorinated biphenyls (PCBs) were quantified in liver tissues of bull sharks (Carcharhinus leucas) ranging in age from 3 yr. Summed values of PCBs (ΣPCBs) ranged from 310 ng/g to 22 070 ng/g (lipid wt) across age classes with ΣPCB concentrations for the youngest sharks in the present study (3-yr-old sharks, highlighting the extent of exposure of this young life stage to this class of persistent organic pollutants (POPs). Age normalization of PCB congener concentrations to those measured for the youngest sharks demonstrated a significant hydrophobicity (log octanol/water partition coefficient [KOW ]) effect that was indicative of maternal offloading of highly hydrophobic (log KOW ≥6.5) congeners to the youngest individuals. A distinct shift in the PCB congener profiles was also observed as these young sharks grew in size. This shift was consistent with a transition from the maternally offloaded signal to the initiation of exogenous feeding and the contributions of mechanisms including growth dilution and whole-body elimination. These results add to the growing pool of literature documenting substantially high concentrations of POPs in juvenile sharks that are most likely attributable to maternal offloading. Collectively, such results underscore the potential vulnerability of young sharks to POP exposure and pose additional concerns for shark-conservation efforts. © 2013 SETAC.

  18. How Full Is Your Luggage? Background Knowledge of Zoo Visitors Regarding Sharks

    Science.gov (United States)

    das Neves, João Pedro Correia; Monteiro, Rute Cristina Rocha

    2013-01-01

    For the general population, sharks have a reputation that does not really fit with their biological and ecological nature. Informal surveys often classify sharks as dangerous, aggressive and/or man-eaters. This apparent common knowledge seems difficult to detach from the conscience of many worldwide zoo visitors, even with the help of…

  19. Ecological impact of the end-Cretaceous extinction on lamniform sharks.

    Science.gov (United States)

    Belben, Rachel A; Underwood, Charlie J; Johanson, Zerina; Twitchett, Richard J

    2017-01-01

    Lamniform sharks are apex marine predators undergoing dramatic local and regional decline worldwide, with consequences for marine ecosystems that are difficult to predict. Through their long history, lamniform sharks have faced widespread extinction, and understanding those 'natural experiments' may help constrain predictions, placing the current crisis in evolutionary context. Here we show, using novel morphometric analyses of fossil shark teeth, that the end-Cretaceous extinction of many sharks had major ecological consequences. Post-extinction ecosystems supported lower diversity and disparity of lamniforms, and were dominated by significantly smaller sharks with slimmer, smoother and less robust teeth. Tooth shape is intimately associated with ecology, feeding and prey type, and by integrating data from extant sharks we show that latest Cretaceous sharks occupied similar niches to modern lamniforms, implying similar ecosystem structure and function. By comparison, species in the depauperate post-extinction community occupied niches most similar to those of juvenile sand tigers (Carcharias taurus). Our data show that quantitative tooth morphometrics can distinguish lamniform sharks due to dietary differences, providing critical insights into ecological consequences of past extinction episodes.

  20. Evidence of positive selection associated with placental loss in tiger sharks.

    Science.gov (United States)

    Swift, Dominic G; Dunning, Luke T; Igea, Javier; Brooks, Edward J; Jones, Catherine S; Noble, Leslie R; Ciezarek, Adam; Humble, Emily; Savolainen, Vincent

    2016-06-14

    All vertebrates initially feed their offspring using yolk reserves. In some live-bearing species these yolk reserves may be supplemented with extra nutrition via a placenta. Sharks belonging to the Carcharhinidae family are all live-bearing, and with the exception of the tiger shark (Galeocerdo cuvier), develop placental connections after exhausting yolk reserves. Phylogenetic relationships suggest the lack of placenta in tiger sharks is due to secondary loss. This represents a dramatic shift in reproductive strategy, and is likely to have left a molecular footprint of positive selection within the genome. We sequenced the transcriptome of the tiger shark and eight other live-bearing shark species. From this data we constructed a time-calibrated phylogenetic tree estimating the tiger shark lineage diverged from the placental carcharhinids approximately 94 million years ago. Along the tiger shark lineage, we identified five genes exhibiting a signature of positive selection. Four of these genes have functions likely associated with brain development (YWHAE and ARL6IP5) and sexual reproduction (VAMP4 and TCTEX1D2). Our results indicate the loss of placenta in tiger sharks may be associated with subsequent adaptive changes in brain development and sperm production.

  1. Variation in depth of whitetip reef sharks: does provisioning ecotourism change their behaviour?

    Science.gov (United States)

    Fitzpatrick, Richard; Abrantes, Kátya G.; Seymour, Jamie; Barnett, Adam

    2011-09-01

    In the dive tourism industry, shark provisioning has become increasingly popular in many places around the world. It is therefore important to determine the impacts that provisioning may have on shark behaviour. In this study, eight adult whitetip reef sharks Triaenodon obesus were tagged with time-depth recorders at Osprey Reef in the Coral Sea, Australia. Tags collected time and depth data every 30 s. The absolute change in depth over 5-min blocks was considered as a proxy for vertical activity level. Daily variations in vertical activity levels were analysed to determine the effects of time of day on whitetip reef shark behaviour. This was done for days when dive boats were absent from the area, and for days when dive boats were present, conducting shark provisioning. Vertical activity levels varied between day and night, and with the presence of boats. In natural conditions (no boats present), sharks remained at more constant depths during the day, while at night animals continuously moved up and down the water column, showing that whitetip reef sharks are nocturnally active. When boats were present, however, there were also long periods of vertical activity during the day. If resting periods during the day are important for energy budgets, then shark provisioning may affect their health. So, if this behaviour alteration occurs frequently, e.g., daily, this has the potential to have significant negative effects on the animals' metabolic rates, net energy gain and overall health, reproduction and fitness.

  2. EFFECT OF FLUORIDE MOUTHRINSING ON CARIES LESION DEVELOPMENT IN SHARK ENAMEL - AN INSITU CARIES MODEL STUDY

    NARCIS (Netherlands)

    OGAARD, B; ROLLA, G; DIJKMAN, T; RUBEN, J; ARENDS, J

    1991-01-01

    Shark enamel consists of nearly pure fluorapatite and has been shown to demineralize in an in situ caries model. The present study was conducted to investigate whether additional fluoride supplementation in the form of mouthrinsing would inhibit lesion development in shark enamel. The study slabs of

  3. Oxidative stability and alpha-tocopherol retention in soybean oil with lemon seed extract (Citrus limon) under thermoxidation.

    Science.gov (United States)

    Luzia, Débora Maria Moreno; Jorge, Neuza

    2009-11-01

    The synergistic effect of lemon seed extract with tert-butylhydroquinone (TBHQ) in soybean oil subjected to thermoxidation by Rancimat was investigated, and the influence of these antioxidants on a-tocopherol degradation in thermoxidized soybean oil. Control, LSE (2400 mg/kg Lemon Seed Extract), TBHQ (50 mg/kg), Mixture 1 (LSE + 50 mg/kg TBHQ) and Mixture 2 (LSE + 25 mg/kg TBHQ) were subjected to 180 degrees C for 20 h. Samples were taken at time 0, 5, 10, 15 and 20 h intervals and analysed for oxidative stability and alpha-tocopherol content. LSE and Mixtures 1 and 2 showed the capacity of retarding lipid oxidation when added to soya oil and also contributed to alpha-tocopherol retention in oil heated at high temperatures. However, Mixtures 1 and 2 added to the oil presented a greater antioxidant power, consequently proving the antioxidants synergistic effect.

  4. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    Science.gov (United States)

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-02-10

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.

  5. Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus)

    Energy Technology Data Exchange (ETDEWEB)

    McMeans, Bailey C., E-mail: bcmcmeans@gmail.com [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); Arts, Michael T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada); National Water Research Institute, Environment Canada, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario L7R 4A6 (Canada); Fisk, Aaron T. [Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4 (Canada)

    2015-03-15

    Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log{sub 10}THg increased significantly with δ{sup 15}N and trophic position from invertebrates (0.01 ± 0.01 μg·g{sup −1} [113 ± 1 ng·g{sup −1}] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg·g{sup −1}). The slope of the log{sub 10}THg vs. δ{sup 15}N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas. - Highlights: • THg significantly increased with δ{sup 15}N from invertebrates to Greenland Sharks. • THg increased with δ{sup 15}N at a faster rate through the pelagic than

  6. Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus)

    International Nuclear Information System (INIS)

    McMeans, Bailey C.; Arts, Michael T.; Fisk, Aaron T.

    2015-01-01

    Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log 10 THg increased significantly with δ 15 N and trophic position from invertebrates (0.01 ± 0.01 μg·g −1 [113 ± 1 ng·g −1 ] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg·g −1 ). The slope of the log 10 THg vs. δ 15 N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas. - Highlights: • THg significantly increased with δ 15 N from invertebrates to Greenland Sharks. • THg increased with δ 15 N at a faster rate through the pelagic than benthic food web. • Benthic primary

  7. Follow-up of the fate of imazalil from post-harvest lemon surface treatment to a baking experiment.

    Science.gov (United States)

    Vass, Andrea; Korpics, Evelin; Dernovics, Mihály

    2015-01-01

    Imazalil is one of the most widespread fungicides used for the post-harvest treatment of citrus species. The separate use of peel during food preparation and processing may hitherto concentrate most of the imazalil into food products, where specific maximum residue limits hardly exist for this fungicide. In order to monitor comprehensively the path of imazalil, our study covered the monitoring of the efficiency of several washing treatments, the comparison of operative and related sample preparation methods for the lemon samples, the validation of a sample preparation technique for a fatty cake matrix, the preparation of a model cake sample made separately either with imazalil containing lemon peel or with imazalil spiking, the monitoring of imazalil degradation into α-(2,4-dichlorophenyl)-1H-imidazole-1-ethanol because of the baking process, and finally the mass balance of imazalil throughout the washing experiments and the baking process. Quantification of imazalil was carried out with an LC-ESI-MS/MS set-up, while LC-QTOF was used for the monitoring of imazalil degradation. Concerning the washing, none of the addressed five washing protocols could remove more than 30% of imazalil from the surface of the lemon samples. The study revealed a significant difference between the extraction efficiency of imazalil by the EN 15662:2008 and AOAC 2007.1 methods, with the advantage of the former. The use of the model cake sample helped to validate a modified version of the EN 15662:2008 method that included a freeze-out step to efficiently recover imazalil (>90%) from the fatty cake matrix. The degradation of imazalil during the baking process was significantly higher when this analyte was spiked into the cake matrix than in the case of preparing the cake with imazalil-containing lemon peel (52% vs. 22%). This observation calls the attention to the careful evaluation of pesticide stability data that are based on solution spiking experiments.

  8. The effect of lemon inhalation aromatherapy on nausea and vomiting of pregnancy: a double-blinded, randomized, controlled clinical trial.

    Science.gov (United States)

    Yavari Kia, Parisa; Safajou, Farzaneh; Shahnazi, Mahnaz; Nazemiyeh, Hossein

    2014-03-01

    Nausea and vomiting of pregnancy are amongst the most common complaints that effects on both the physical and mental conditions of the pregnant women. Due to the increasing tendency of women to use herbal medications during pregnancy, the effect of lemon inhalation aromatherapy on nausea and vomiting of pregnancy was investigated in this study. The aim of this study was to determine the effect of lemon inhalation aromatherapy on nausea and vomiting during pregnancy. This was a randomized clinical trial in which 100 pregnant women with nausea and vomiting who had eligibility criteria were randomly divided into intervention and control groups based on four- and six-random block sampling method. Lemon essential oil and placebo were given to the intervention and control groups, respectively, to inhale it as soon as they felt nausea. The nausea, vomiting, and retch intensity were investigated 24 hours before and during the four days of treatment by means of PUQE-24 (24-hour Pregnancy Unique Quantification of Emesis). There was a statistically significant difference between the two groups in the mean scores of nausea and vomiting on the second and fourth days (P = 0.017 and P = 0.039, respectively). The means of nausea and vomiting intensity in the second and fourth days in the intervention group were significantly lower than the control group. In addition, in intragroup comparison with ANOVA with repeated measures, the nausea and vomiting mean in the five intervals, showed a statistically significant difference in each group (P < 0.001 and P = 0.049, respectively). Lemon scent can be effective in reducing nausea and vomiting of pregnancy.

  9. NUMERICAL SIMULATION AND EXPERIMENTAL STUDY OF DRAGREDUCING SURFACE OF A REAL SHARK SKIN*

    Institute of Scientific and Technical Information of China (English)

    ZHANG De-yuan; LUO Yue-hao; LI Xiang; CHEN Hua-wei

    2011-01-01

    It is well known that shark skin surface can effectively inhabit the occurrence of turbulence and reduce the wall friction,but in order to understand the mechanism of drag reduction, one has to solve the problem of the turbulent flow on grooved-scale surface, and in that respect, the direct numerical simulation is an important tool.In this article, based on the real biological shark skin,the model of real shark skin is built through high-accurate scanning and data processing.The turbulent flow on a real shark skin is comprehensively simulated, and based on the simulation, the drag reduction mechanism is discussed.In addition, in order to validate the drag-reducing effect of shark skin surface, actual experiments were carried out in water tunnel, and the experimental results are approximately consistent with the numerical simulation.

  10. Gross morphology and histology of the olfactory organ of the Greenland shark Somniosus microcephalus

    DEFF Research Database (Denmark)

    Ferrando, S.; Gallus, L.; Ghigliotti, L.

    2016-01-01

    The Greenland shark (Somniosus microcephalus) is the largest predatory fish in Arctic waters. Knowledge of the fundamental biology and ecological role of the Greenland shark is limited, and the sensory biology of the Greenland shark has been poorly studied. Given the potential relevant contribution...... of chemoreception to the sensory capability of the Greenland shark to forage and navigate in low-light environments, we examined the architecture of the peripheral olfactory organ (the olfactory rosette) through morphological, histological and immunohistochemical assays. We found that each olfactory rosette...... neurons, presence of unusually large cells along the olfactory fiber bundles) deserve further investigation. Overall, the structure of the olfactory rosette suggests a well-developed olfactory capability for the Greenland shark coherent with a bentho-pelagic lifestyle....

  11. Pharmacokinetics of cefovecin (Convenia) in white bamboo sharks (Chiloscyllium plagiosum) and Atlantic horseshoe crabs (Limulus polyphemus).

    Science.gov (United States)

    Steeil, James C; Schumacher, Juergen; George, Robert H; Bulman, Frank; Baine, Katherine; Cox, Sherry

    2014-06-01

    Cefovecin was administered to six healthy adult white bamboo sharks (Chiloscyllium plagiosum) and six healthy adult Atlantic horseshoe crabs (Limulus polyphemus) to determine its pharmacokinetics in these species. A single dose of cefovecin at 8 mg/kg was administered subcutaneously in the epaxial region of the bamboo sharks and in the proximal articulation of the lateral leg of the horseshoe crabs. Blood and hemolymph samples were collected at various time points from bamboo sharks and Atlantic horseshoe crabs. High performance liquid chromatography was performed to determine plasma levels of cefovecin. The terminal halflife of cefovecin in Atlantic horseshoe crabs was 37.70 +/- 9.04 hr and in white bamboo sharks was 2.02 +/- 4.62 hr. Cefovecin concentrations were detected for 4 days in white bamboo sharks and for 14 days in Atlantic horseshoe crabs. No adverse effects associated with cefovecin administration were seen in either species.

  12. Acoustic Monitoring of a Previously Unstudied Whale Shark Aggregation in the Red Sea

    KAUST Repository

    Cochran, Jesse

    2012-01-01

    The whale shark (Rhincodon, typus), is a large, pelagic, filter feeder for which the available information is limited. The Red Sea populations in particular are practically unstudied. An aggregation site was recently discovered off the western coast of Saudi Arabia. We report the use of passive acoustic monitoring to assess the spatial and temporal behavior patterns of whale sharks in this new site. The aggregation occurs in the spring and peaks in April/ May. Whale sharks showed a preference for a single near shore reef and even a specific area within it. There is no evidence of sexual segregation as the genders were present in roughly equal proportion and used the same habitat at similar times. This information can be used to guide future studies in the area and to inform local management. Continued study will add to the collective knowledge on Red Sea whale sharks, including the population dynamics within the region and how they interact with the global whale shark community.

  13. Shark Attacks in Dakar and the Cap Vert Peninsula, Senegal: Low Incidence despite High Occurrence of Potentially Dangerous Species

    OpenAIRE

    Trape, Sébastien

    2008-01-01

    BACKGROUND: The International Shark Attack File mentions only four unprovoked shark attacks on the coast of West Africa during the period 1828-2004, an area where high concentrations of sharks and 17 species potentially dangerous to man have been observed. To investigate if the frequency of shark attacks could be really low and not just under-reported and whether there are potentially sharks that might attack in the area, a study was carried out in Dakar and the Cap Vert peninsula, Senegal. M...

  14. Endohelminth parasites of the leafscale gulper shark, Centrophorus squamosus (Bonnaterre, 1788) (Squaliformes:Centrophoridae) off Madeira Archipelago.

    Science.gov (United States)

    Costa, Graça; Chada, Tomás; Melo-Moreira, Egberto; Cavallero, Serena; D'Amelio, Stefano

    2014-06-01

    The endohelminth parasite fauna of a deep water shark, the leafscale gulper shark, Centrophorus squamosus, examined from Madeiran waters, from September 2009 to January 2010, consisted of larval and juvenile cestodes of two orders, namely Trypanorhyncha and Tetraphyllidea, and L3 stages of Anisakis spp. Infection with Anisakis spp. could be due to the shark's opportunistic feeding on squids and black-scabbard fish, Aphanopus carbo, which is heavily parasitized by Anisakis spp. in Madeira waters. The occurrence of larval and juvenile cestodes only, in this shark, suggests that the leafscale gulper shark features as a paratenic or a dead-end host for the parasites.

  15. Box-Jenkins analysis for shark landings in Costa Rica

    Directory of Open Access Journals (Sweden)

    Roger Bonilla

    2004-12-01

    Full Text Available Sharks are highly vulnerable to intense and prolonged fishery extraction. This article analyzes the data on shark landings from the artisan fishing fleet on Costa Rica’s Pacific coast between 1988 and 1997. The data come from an invoicing system administered by the Costa Rican Fisheries Institute (Instituto Costarricense de la Pesca y Acuacultura, INCOPESCA. Pacific coast shark fishing during the period under study represented approximately 20% of the total national fisheries volume. According to data from the invoicing system, the Northern Pacific region was the most productive, reporting 58% of the shark catch nationwide. Within this region, shark fishing in Papagayo Gulf represented 91% and 53% of the landings by fishery region and nationwide, respectively. The mid-sized and advanced (length of boat > 10 meters artisan fishing fleets reported 96% of the shark catches in the zone. The study of shark fisheries in the Papagayo Gulf zone is crucial for an understanding of fishery dynamics for this resource at the national level. A monthly chronological series was constructed with the landings in the Papagayo Gulf zone, and a Univariate Box-Jenkins (UBJ Model was estimated for first-order moving averages MA(1 with a seasonal component of the Yt = lambda a t + gamma S12 + a t typeEn este trabajo, se analizaron los datos de desembarque de tiburón de la flota pesquera artesanal en el Pacífico costarricense entre 1988 y 1997. Los datos provienen de un sistema de facturas administrado por el Instituto Costarricense de la Pesca (INCOPESCA. En el Pacífico, la pesca de tiburón en el período de estudio representó aproximadamente el 20% del volumen total de pesca a nivel nacional. De acuerdo con los datos del sistema de facturas, la región del Pacífico Norte fue la más productiva, reportando un 58% de los desembarques de tiburón a nivel nacional. En esta región, la pesca de tiburón en la zona del Golfo de Papagayo reportó 91% y 53% de los

  16. Effect of Fruit Lemon Juice Addition to The Content of Protein, Fat, Lactose and Probiotic on Soy Yogurt

    Science.gov (United States)

    Supriyanti, F. M. T.; Zackiyah; Azizah, N.

    2017-02-01

    This research aimed to determine the effect of lemon juice to the content of protein, fat, lactose and probiotics, in beverages soy yogurt. Soy yogurt which produced was a multifunction yogurt drink high levels of antioxidants, contains probiotics and can be used by people with lactose intolerance. The research method includes the production of fortified soy yogurt with lemon juice, were made with the ratio between the lemon juice and soy yogurt were 0:10 (L0); 1:9 (L1); 2:8 (L2); and 3:7 (L3). Analysis of the results include the content of protein by Kjeldahl method, the content of fat by Soxhletasi method, lactose test by Luff Schoorls method and content of probiotics with total plate count enumeration techniques. The results showed fortified yogurt had a protein content greater than before fortification (L3 > L2 > L1 > L0); The fat content L0 > L1 > L2 > L3. Fortified yogurt lactose content is smaller than before fortification (L0 > L1 > L2 > L3). The content of probiotic yogurt fortified L1 > L3 > L2. From this research can be concluded that the yoghurt fortified (L3) is the best, with the highest protein content, low fat, low lactose than L1 and L2, and had probiotics content. It is advised to conduct further research on the expired time of fortified soy yogurt products

  17. Volatile fraction composition and physicochemical parameters as tools for the differentiation of lemon blossom honey and orange blossom honey.

    Science.gov (United States)

    Kadar, Melinda; Juan-Borrás, Marisol; Carot, Jose M; Domenech, Eva; Escriche, Isabel

    2011-12-01

    Volatile fraction profile and physicochemical parameters were studied with the aim of evaluating their effectiveness for the differentiation between lemon blossom honey (Citrus limon L.) and orange blossom honey (Citrus spp.). They would be useful complementary tools to the traditional analysis based on the percentage of pollen. A stepwise discriminant analysis constructed using 37 volatile compounds (extracted by purge and trap and analysed by gas chromatography-mass spectrometry), and physicochemical and colour parameters (diastase, conductivity, Pfund colour and CIE L a b) together provided a model that permitted the correct classification of 98.3% of the original and 96.6% of the cross-validated cases, indicating its efficiency and robustness. This model proved its effectiveness in the differentiation of both types of honey with another set of batches from the following year. This model, developed from the volatile compounds, physicochemical and colour parameters, has been useful for the differentiation of lemon and orange blossom honeys. Furthermore, it may be of particular interest for the attainment of a suitable classification of orange honey in which the pollen count is very low. These capabilities imply an evident marketing advantage for the beekeeping sector, since lemon blossom honey could be commercialized as unifloral honey and not as generic citrus honey and orange blossom honey could be correctly characterized. Copyright © 2011 Society of Chemical Industry.

  18. Application of fourier-transform infrared (ft-ir) spectroscopy for determination of total phenolics of freeze dried lemon juices

    International Nuclear Information System (INIS)

    Sherazi, S.T.H.; Bhutto, A.A.; Mehesar, S.A.

    2017-01-01

    A cost effective and environmentally safe analytical method for rapid assessment of total phenolic content (TPC) in freeze dried lemon juice samples was developed using transmission Fourier-transform infrared spectroscopy (FT-IR) in conjunction with chemometric techniques. Two types of calibrations i.e. simple Beer's law and partial least square (PLS) were applied to investigate most accurate calibration model based on region from1420 to 1330 cm-1. The better analytical performance was obtained by PLS technique coefficient of determination (R2), root mean square error of calibration (RMSEC) with the value of 0.999 and 0.00864, respectively. The results of TPC in freeze dried lemon juice samples obtained by transmission FT-IR were compared with TPC observed by Folin-Ciocalteu (FC) assay and found to be comparable. Outcomes of the present study indicate that transmission FT-IR spectroscopic approach could be used as an alternative approach in place of Folin-Ciocalteu (FC) assay which is expensive and time-consuming conventional chemical methods for determination of the total phenolic content of lemon fruits. (author)

  19. Effects of ascorbic acid, salt, lemon juice, and honey on drying kinetics and sensory characteristic of dried mango

    Directory of Open Access Journals (Sweden)

    E. E. Abano

    2013-01-01

    Full Text Available The effects of ascorbic acid, salt solution, lemon juice, and honey pretreatment on the drying kinetics and sensory characteristics were studied. Pretreatments used affected the effective moisture diffusivity and rehydration properties of the dried mangoes. The effective moisture diffusivity values were 2.22 × 10-10 m2/s for ascorbic acid, 1.80 × 10-10 m2/s for salt solution, 2.01 × 10-10 m2/s for lemon juice, 1.93 × 10-10 m2/s for honey pretreated mangoes, and 2.31 × 10-10 m2/s for the control slices. Pretreatments enhanced the drying rate potential of mangoes. Among the thin-layer drying models fitted to the experimental data, the Middil model gave the best fit. The ascorbic acid pretreated samples were the best while the salt solution ones were the poorest with respect to reconstitution capacity. Consumer studies for overall preference for taste, colour, texture, flavour and chewiness of the dried products revealed that there was a higher preference for honey pretreated dried samples followed by the ascorbic acid, control, lemon juice, and salt solution pretreated samples. The results demonstrate that these pretreatments can be applied to enhance the moisture transport during drying and the quality of the dried products.

  20. Effective mitigation of debris flows at Lemon Dam, La Plata County, Colorado

    Science.gov (United States)

    deWolfe, V.G.; Santi, P.M.; Ey, J.; Gartner, J.E.

    2008-01-01

    To reduce the hazards from debris flows in drainage basins burned by wildfire, erosion control measures such as construction of check dams, installation of log erosion barriers (LEBs), and spreading of straw mulch and seed are common practice. After the 2002 Missionary Ridge Fire in southwest Colorado, these measures were implemented at Knight Canyon above Lemon Dam to protect the intake structures of the dam from being filled with sediment. Hillslope erosion protection measures included LEBs at concentrations of 220-620/ha (200-600% of typical densities), straw mulch was hand spread at concentrations up to 5.6??metric tons/hectare (125% of typical densities), and seeds were hand spread at 67-84??kg/ha (150% of typical values). The mulch was carefully crimped into the soil to keep it in place. In addition, 13 check dams and 3 debris racks were installed in the main drainage channel of the basin. The technical literature shows that each mitigation method working alone, or improperly constructed or applied, was inconsistent in its ability to reduce erosion and sedimentation. At Lemon Dam, however, these methods were effective in virtually eliminating sedimentation into the reservoir, which can be attributed to a number of factors: the density of application of each mitigation method, the enhancement of methods working in concert, the quality of installation, and rehabilitation of mitigation features to extend their useful life. The check dams effectively trapped the sediment mobilized during rainstorms, and only a few cubic meters of debris traveled downchannel, where it was intercepted by debris racks. Using a debris volume-prediction model developed for use in burned basins in the Western U.S., recorded rainfall events following the Missionary Ridge Fire should have produced a debris flow of approximately 10,000??m3 at Knight Canyon. The mitigation measures, therefore, reduced the debris volume by several orders of magnitude. For comparison, rainstorm

  1. Lemon grass (Cymbopogon citratus essential oil as a potent anti-inflammatory and antifungal drugs

    Directory of Open Access Journals (Sweden)

    Mohamed Nadjib Boukhatem

    2014-09-01

    Full Text Available Background: Volatile oils obtained from lemon grass [Cymbopogon citratus (DC. Stapf, Poaceae family] are used in traditional medicine as remedies for the treatment of various diseases. Aims: In the present study, lemon grass essential oil (LGEO was evaluated for its in vivo topical and oral anti-inflammatory effects, and for its in vitro antifungal activity using both liquid and vapor phases. Methods: The chemical profile of LGEO as determined by gas chromatography–mass spectrometry analysis revealed two major components: geranial (42.2%, and neral (31.5%. The antifungal activity of LGEO was evaluated against several pathogenic yeasts and filamentous fungi using disc diffusion and vapor diffusion methods. Results: LGEO exhibited promising antifungal effect against Candida albicans, C. tropicalis, and Aspergillus niger, with different inhibition zone diameters (IZDs (35–90 mm. IZD increased with increasing oil volume. Significantly, higher anti-Candida activity was observed in the vapor phase. For the evaluation of the anti-inflammatory effect, LGEO (10 mg/kg, administered orally significantly reduced carrageenan-induced paw edema with a similar effect to that observed for oral diclofenac (50 mg/kg, which was used as the positive control. Oral administration of LGEO showed dose-dependent anti-inflammatory activity. In addition, topical application of LGEO in vivo resulted in a potent anti-inflammatory effect, as demonstrated by using the mouse model of croton oil-induced ear edema. To our knowledge, this is the first such report to be published. The topical application of LGEO at doses of 5 and 10 µL/ear significantly reduced acute ear edema induced by croton oil in 62.5 and 75% of the mice, respectively. In addition, histological analysis clearly confirmed that LGEO inhibits the skin inflammatory response in animal models. Conclusion: Results of the present study indicate that LGEO has a noteworthy potential for the development of drugs for

  2. Diet and condition of mesopredators on coral reefs in relation to shark abundance.

    Science.gov (United States)

    Barley, Shanta C; Meekan, Mark G; Meeuwig, Jessica J

    2017-01-01

    Reef sharks may influence the foraging behaviour of mesopredatory teleosts on coral reefs via both risk effects and competitive exclusion. We used a "natural experiment" to test the hypothesis that the loss of sharks on coral reefs can influence the diet and body condition of mesopredatory fishes by comparing two remote, atoll-like reef systems, the Rowley Shoals and the Scott Reefs, in northwestern Australia. The Rowley Shoals are a marine reserve where sharks are abundant, whereas at the Scott Reefs numbers of sharks have been reduced by centuries of targeted fishing. On reefs where sharks were rare, the gut contents of five species of mesopredatory teleosts largely contained fish while on reefs with abundant sharks, the same mesopredatory species consumed a larger proportion of benthic invertebrates. These measures of diet were correlated with changes in body condition, such that the condition of mesopredatory teleosts was significantly poorer on reefs with higher shark abundance. Condition was defined as body weight, height and width for a given length and also estimated via several indices of condition. Due to the nature of natural experiments, alternative explanations cannot be discounted. However, the results were consistent with the hypothesis that loss of sharks may influence the diet and condition of mesopredators and by association, their fecundity and trophic role. Regardless of the mechanism (risk effects, competitive release, or other), our findings suggest that overfishing of sharks has the potential to trigger trophic cascades on coral reefs and that further declines in shark populations globally should be prevented to protect ecosystem health.

  3. Modulation of shark prey capture kinematics in response to sensory deprivation.

    Science.gov (United States)

    Gardiner, Jayne M; Atema, Jelle; Hueter, Robert E; Motta, Philip J

    2017-02-01

    The ability of predators to modulate prey capture in response to the size, location, and behavior of prey is critical to successful feeding on a variety of prey types. Modulating in response to changes in sensory information may be critical to successful foraging in a variety of environments. Three shark species with different feeding morphologies and behaviors were filmed using high-speed videography while capturing live prey: the ram-feeding blacktip shark, the ram-biting bonnethead, and the suction-feeding nurse shark. Sharks were examined intact and after sensory information was blocked (olfaction, vision, mechanoreception, and electroreception, alone and in combination), to elucidate the contribution of the senses to the kinematics of prey capture. In response to sensory deprivation, the blacktip shark demonstrated the greatest amount of modulation, followed by the nurse shark. In the absence of olfaction, blacktip sharks open the jaws slowly, suggestive of less motivation. Without lateral line cues, blacktip sharks capture prey from greater horizontal angles using increased ram. When visual cues are absent, blacktip sharks elevate the head earlier and to a greater degree, allowing them to overcome imprecise position of the prey relative to the mouth, and capture prey using decreased ram, while suction remains unchanged. When visual cues are absent, nurse sharks open the mouth wider, extend the labial cartilages further, and increase suction while simultaneously decreasing ram. Unlike some bony fish, neither species switches feeding modalities (i.e. from ram to suction or vice versa). Bonnetheads failed to open the mouth when electrosensory cues were blocked, but otherwise little to no modulation was found in this species. These results suggest that prey capture may be less plastic in elasmobranchs than in bony fishes, possibly due to anatomical differences, and that the ability to modulate feeding kinematics in response to available sensory information varies

  4. Diet and condition of mesopredators on coral reefs in relation to shark abundance.

    Directory of Open Access Journals (Sweden)

    Shanta C Barley

    Full Text Available Reef sharks may influence the foraging behaviour of mesopredatory teleosts on coral reefs via both risk effects and competitive exclusion. We used a "natural experiment" to test the hypothesis that the loss of sharks on coral reefs can influence the diet and body condition of mesopredatory fishes by comparing two remote, atoll-like reef systems, the Rowley Shoals and the Scott Reefs, in northwestern Australia. The Rowley Shoals are a marine reserve where sharks are abundant, whereas at the Scott Reefs numbers of sharks have been reduced by centuries of targeted fishing. On reefs where sharks were rare, the gut contents of five species of mesopredatory teleosts largely contained fish while on reefs with abundant sharks, the same mesopredatory species consumed a larger proportion of benthic invertebrates. These measures of diet were correlated with changes in body condition, such that the condition of mesopredatory teleosts was significantly poorer on reefs with higher shark abundance. Condition was defined as body weight, height and width for a given length and also estimated via several indices of condition. Due to the nature of natural experiments, alternative explanations cannot be discounted. However, the results were consistent with the hypothesis that loss of sharks may influence the diet and condition of mesopredators and by association, their fecundity and trophic role. Regardless of the mechanism (risk effects, competitive release, or other, our findings suggest that overfishing of sharks has the potential to trigger trophic cascades on coral reefs and that further declines in shark populations globally should be prevented to protect ecosystem health.

  5. Shark attack-related injuries: Epidemiology and implications for plastic surgeons.

    Science.gov (United States)

    Ricci, Joseph A; Vargas, Christina R; Singhal, Dhruv; Lee, Bernard T

    2016-01-01

    The increased media attention to shark attacks has led to a heightened fear and public awareness. Although few sharks are considered dangerous, attacks on humans can result in large soft tissue defects necessitating the intervention of reconstructive surgeons. This study aims to evaluate and describe the characteristics of shark-related injuries in order to improve treatment. The Global Shark Accident File, maintained by the Shark Research Institute (Princeton, NJ, USA), is a compilation of all known worldwide shark attacks. Database records since the 1900s were reviewed to identify differences between fatal and nonfatal attacks, including: geography, injury pattern, shark species, and victim activity. Since the 1900s, there have been 5034 reported shark attacks, of which 1205 (22.7%) were fatal. Although the incidence of attacks per decade has increased, the percentage of fatalities has decreased. Characteristics of fatal attacks included swimming (p = 0.001), boating (p = 0.001), three or more bite sites (p = 0.03), limb loss (p = 0.001), or tiger shark attack (p = 0.002). The most common attacks were bites to the legs (41.8%) or arms (18.4%), with limb loss occurring in 7% of attacks. Geographically, the majority of attacks occurred in North America (36.7%) and Australia (26.5%). Most attacks in the USA occurred in Florida (49.1%) and California (13.6%). Although rare, shark attacks result in devastating injuries to patients. As these injuries often involve multiple sites and limb loss, this creates a significant challenge for reconstructive surgeons. Proper identification of the characteristics of the attack can aid in providing optimal care for those affected. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  6. The Economy of Shark Conservation in the Northeast Pacific: The Role of Ecotourism and Citizen Science.

    Science.gov (United States)

    Mieras, Peter A; Harvey-Clark, Chris; Bear, Michael; Hodgin, Gina; Hodgin, Boone

    Historically sharks have been seen either as a source of income through harvesting, or as a nuisance and danger. The economic value of sharks has traditionally been measured as the total value of sharks caught for liver oil, fins, or meat for consumption. Sharks have also been killed to near extinction in cases where they were seen as a threat to fisheries on other species. This is illustrated by the mass extermination of Basking Sharks (Cetorhinus maximus) in British Columbia. They were seen as a nuisance to fishermen as they got entangled in gill nets during the salmon fishing season. However with the development of the SCUBA diving industry, and ecotourism in general, increased awareness of the role sharks play in marine ecosystems has resulted in changes in how they are perceived and utilized. Despite an ongoing harvest of sharks such as the North Pacific Spiny Dogfish (Squalus suckleyi), sharks now generate economic value through SCUBA diving enthusiasts who travel the globe to see, swim with, and photograph them. The use of digital cameras and other digital media has brought sharks into households around the world and increased awareness of the conservation issues facing many species. This renewed appreciation has led to a better understanding of sharks by the public, resulting in advocates calling for better protections and conservation. In particular, a growing part of the SCUBA diving community wants to contribute to conservation and research projects, which has led to participation in citizen science projects. These projects provide scientific data but also gain ground as ecotourism activities, thus adding to both economic value of tourism and conservation efforts. © 2017 Elsevier Ltd All rights reserved.

  7. 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

  8. Residency, Habitat Use and Sexual Segregation of White Sharks, Carcharodon carcharias in False Bay, South Africa

    Science.gov (United States)

    Kock, Alison; O’Riain, M. Justin; Mauff, Katya; Meÿer, Michael; Kotze, Deon; Griffiths, Charles

    2013-01-01

    White sharks (Carcharodon carcharias) are threatened apex predators and identification of their critical habitats and how these are used are essential to ensuring improved local and ultimately global white shark protection. In this study we investigated habitat use by white sharks in False Bay, South Africa, using acoustic telemetry. 56 sharks (39 female, 17 male), ranging in size from 1.7–5 m TL, were tagged with acoustic transmitters and monitored on an array of 30 receivers for 975 days. To investigate the effects of season, sex and size on habitat use we used a generalized linear mixed effects model. Tagged sharks were detected in the Bay in all months and across all years, but their use of the Bay varied significantly with the season and the sex of the shark. In autumn and winter males and females aggregated around the Cape fur seal colony at Seal Island, where they fed predominantly on young of the year seals. In spring and summer there was marked sexual segregation, with females frequenting the Inshore areas and males seldom being detected. The shift from the Island in autumn and winter to the Inshore region in spring and summer by females mirrors the seasonal peak in abundance of juvenile seals and of migratory teleost and elasmobranch species respectively. This study provides the first evidence of sexual segregation at a fine spatial scale and demonstrates that sexual segregation in white sharks is not restricted to adults, but is apparent for juveniles and sub-adults too. Overall, the results confirm False Bay as a critical area for white shark conservation as both sexes, across a range of sizes, frequent the Bay on an annual basis. The finding that female sharks aggregate in the Inshore regions when recreational use peaks highlights the need for ongoing shark-human conflict mitigation strategies. PMID:23383052

  9. Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge.

    Science.gov (United States)

    Martins, Ana Paula Barbosa; Feitosa, Leonardo Manir; Lessa, Rosangela Paula; Almeida, Zafira Silva; Heupel, Michelle; Silva, Wagner Macedo; Tchaicka, Ligia; Nunes, Jorge Luiz Silva

    2018-01-01

    Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries.

  10. Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge

    Science.gov (United States)

    Almeida, Zafira Silva; Heupel, Michelle; Silva, Wagner Macedo; Tchaicka, Ligia

    2018-01-01

    Increasing fishing effort has caused declines in shark populations worldwide. Understanding biological and ecological characteristics of sharks is essential to effectively implement management measures, but to fully understand drivers of fishing pressure social factors must be considered through multidisciplinary and integrated approaches. The present study aimed to use fisher and trader knowledge to describe the shark catch and product supply chain in Northeastern Brazil, and evaluate perceptions regarding the regional conservation status of shark species. Non-systematic observations and structured individual interviews were conducted with experienced fishers and traders. The demand and economic value of shark fins has reportedly decreased over the last 10 years while the shark meat trade has increased slightly, including a small increase in the average price per kilogram of meat. Several threatened shark species were reportedly often captured off shore and traded at local markets. This reported and observed harvest breaches current Brazilian environmental laws. Fishing communities are aware of population declines of several shark species, but rarely take action to avoid capture of sharks. The continuing capture of sharks is mainly due to a lack of knowledge of environmental laws, lack of enforcement by responsible authorities, and difficulties encountered by fishers in finding alternative income streams. National and regional conservation measures are immediately required to reduce overfishing on shark populations in Northeastern Brazil. Social and economic improvements for poor fishing communities must also be implemented to achieve sustainable fisheries. PMID:29534100

  11. Multi-Year Impacts of Ecotourism on Whale Shark (Rhincodon typus) Visitation at Ningaloo Reef, Western Australia.

    Science.gov (United States)

    Sanzogni, R L; Meekan, M G; Meeuwig, J J

    2015-01-01

    In-water viewing of sharks by tourists has become a popular and lucrative industry. There is some concern that interactions with tourists with ecotourism operations might harm sharks through disruption of behaviours. Here, we analysed five years of whale shark (Rhincodon typus) encounter data by an ecotourism industry at Ningaloo Reef, Western Australia, to assess the impact of ecotourism interactions on shark visitation, within the context of the biological and physical oceanography of the region. Our data base consisted of 2823 encounter records for 951 individual whale sharks collected by ecotourism operators between 2007 and 2011. We found that total encounters per whale shark and encounters per boat trip increased through time. On average, whale sharks re-encountered in subsequent years were encountered earlier, stayed longer and tended to be encountered more often within a season than sharks that were only encountered in a single year. Sequential comparisons between years did not show any patterns consistent with disturbance and the rate of departure of whale sharks from the aggregation was negatively correlated to the number of operator trips. Overall, our analysis of this multi-year data base found no evidence that interactions with tourists affected the likelihood of whale shark re-encounters and that instead, physical and biological environmental factors had a far greater influence on whale shark visitation rates. Our approach provides a template for assessing the effects of ecotourism interactions and environmental factors on the visitation patterns of marine megafauna over multiple years.

  12. Identification and evaluation of shark bycatch in Georgia’s commercial shrimp trawl fishery with implications for management

    Science.gov (United States)

    Belcher, C.N.; Jennings, Cecil A.

    2011-01-01

    Many US states have recreational and commercial fisheries that occur in nursery areas occupied by subadult sharks and can potentially affect their survival. Georgia is one of few US states without a directed commercial shark fishery, but the state has a large, nearshore penaeid shrimp trawl fishery in which small sharks occur as bycatch. During our 1995-1998 investigation of bycatch in fishery-dependent sampling events, 34% of 127 trawls contained sharks. This bycatch totalled 217 individuals from six species, with Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson), the most common and finetooth shark, Carcharhinus isodon (Müller & Henle) and spinner shark, Carcharhinus brevipinna (Müller & Henle), the least common. The highest catch rates for sharks occurred during June and July and coincided with the peak months of the pupping season for many species. Trawl tow speed and tow time did not significantly influence catch rates for shark species. Gear configurations [net type, turtle excluder device (TED), bycatch reduction device] affected catch rates for shark species. Results of this study indicate gear restrictions, a delayed season opening, or reduced bar spacing on TEDs may reduce shark bycatch in this fishery.

  13. Biochemical components and dry matter of lemon and mandarin hybrids under salt stress

    Directory of Open Access Journals (Sweden)

    Francisco V. da S. Sá

    Full Text Available ABSTRACT The objective was to study the biochemical changes and dry matter content in lemon and mandarin hybrids under salt stress during rootstock formation. For this, a study was conducted in randomized complete block, using a 2 x 5 factorial scheme, with two salinity levels (0.3 and 4.0 dS m-1 applied in five citrus rootstock genotypes (1. TSKC x CTARG - 019; 2. LRF; 3. TSKC x (LCR x TR - 040; 4. LCRSTC and 5. LVK, with three replicates and four plants per plot. At 90 days after sowing, saline treatments started to be applied and continued until 120 days after sowing, the moment in which the plants were collected for evaluation of biochemical characteristics and phytomass accumulation. The increase in water salinity negatively affected the biochemical components and dry matter accumulation of citrus genotypes. The genotypes TSKC x (LCR x TR - 040, LCRSTC and LVK were the least affected by salt stress, standing out as the materials most tolerant to salinity.

  14. Fast Lemons and Sour Boulders: Testing Crossmodal Correspondences Using an Internet-Based Testing Methodology

    Directory of Open Access Journals (Sweden)

    Andy T. Woods

    2013-09-01

    Full Text Available According to a popular family of hypotheses, crossmodal matches between distinct features hold because they correspond to the same polarity on several conceptual dimensions (such as active–passive, good–bad, etc. that can be identified using the semantic differential technique. The main problem here resides in turning this hypothesis into testable empirical predictions. In the present study, we outline a series of plausible consequences of the hypothesis and test a variety of well-established and previously untested crossmodal correspondences by means of a novel internet-based testing methodology. The results highlight that the semantic hypothesis cannot easily explain differences in the prevalence of crossmodal associations built on the same semantic pattern (fast lemons, slow prunes, sour boulders, heavy red; furthermore, the semantic hypothesis only minimally predicts what happens when the semantic dimensions and polarities that are supposed to drive such crossmodal associations are made more salient (e.g., by adding emotional cues that ought to make the good/bad dimension more salient; finally, the semantic hypothesis does not explain why reliable matches are no longer observed once intramodal dimensions with congruent connotations are presented (e.g., visually presented shapes and colour do not appear to correspond.

  15. Kinetics of ascorbic acid degradation in un-pasteurized Iranian lemon juice during regular storage conditions.

    Science.gov (United States)

    Abbasi, A; Niakousari, M

    2008-05-15

    The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 +/- 3 degrees C) and in the refrigerator (3 +/- 1 degrees C). Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method in the presence of 2,6-dichlorophenol indophenol. The study was carried out for 12 weeks after which slight changes in color, taste and apparent texture in some samples were observed and ascorbic acid content reduced by 50%. Soluble solids content, pH value and total acidity were 5.5 degrees Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly influenced by storage time or conditions. Ascorbic acid content initially at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the first three weeks of storage. The final ascorbic acid content of all samples was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in the juice at all conditions followed a first-order kinetic model with activation energy of 137 cal mol(-1).

  16. Orange fiber as a novel fat replacer in lemon ice cream

    Directory of Open Access Journals (Sweden)

    Tainara de Moraes Crizel

    2014-06-01

    Full Text Available Orange fiber was used as a novel fat replacer in light lemon ice cream. Nine ice cream formulations were compared: standard control ice cream (IC; ice cream with fiber (F1 from the peel, bagasse, and orange seed (ICA and ICB; ice cream with fiber (F2 from the orange peel alone (ICC and ICD; ice cream with fiber (F3 from the peel, bagasse, and orange seed pretreated with hydro-distillation (ICE and ICF; and ice cream with fiber (F4 from the orange peel pretreated with hydro-distillation (ICG and ICH.The orange fiber reduced the ice cream fat content (50 % and the overrun ratio and increased the fiber content and the hardness, gumminess, and springiness values, but it did not affect the adhesiveness and odor of the samples. The samples with 1.0 % of orange fiber showed low melting rate values than those of the control ice cream. The overall acceptance of the ice cream with 1.0 % of pre-treated orange peel fiber did not differ from that of the control ice cream (80 %. The orange fiber proved a promising food ingredient since it can be used to decrease the fat content and increase bioactive compounds content, such as fiber and carotenoids.

  17. Preliminary assessment of trace elements effects on essential oil production of Melissa officinalis L. (Lemon balm)

    International Nuclear Information System (INIS)

    Sussa, Fabio V.; Duarte, Celina L.; Andrade, Luana S.; Silva, Paulo S.C.; Furlan, Marcos R.

    2013-01-01

    Melissa officinalis L., Lemon balm, (Lamiaceae) is an herb used as medicine, condiment and in the cosmetic and perfumery industry due to its essential oil. In this study a preliminary assessment of trace elements effects on essential oil production was performed in order to verify an improvement in its quality. The Melissa officinalis samples were harvested from three different soil sites localized in Ibirapuera Park, São Paulo, Brazil. Elemental concentration for the elements As, Ba, Br, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Ti, Th, U, V, Yb, Zn and Zr was determined by Instrumental Neutron Activation Analysis (INAA) in Melissa officinalis leaves and surrounding soil. The essential oil was extracted from its leaves by hydrodistillation process in Clevenger apparatus and analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Certified reference materials NIST SRM-1515 Apple Leaves, NIST SRM-1547 Peach Leaves and NIST SRM-1573a Tomato Leaves were analyzed for quality control. Our results showed Geranial and Neral were identified as the major compounds in the essential oil extracted from Melissa officinalis L. for all collected sites. However, the relative proportion of some chemical constituents was altered according to the site collected. The preliminary results showed that the production of essential oil by Melissa officinalis must be positively correlated with the concentrations of Rb, Zn and negatively correlated with Sc, Mn, La, K, Fe, and Cr. (author)

  18. Preliminary assessment of trace elements effects on essential oil production of Melissa officinalis L. (Lemon balm)

    Energy Technology Data Exchange (ETDEWEB)

    Sussa, Fabio V.; Duarte, Celina L.; Andrade, Luana S.; Silva, Paulo S.C., E-mail: pscsilva@ipen.br, E-mail: clduarte@ipen.br, E-mail: fabiosussa@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Furlan, Marcos R., E-mail: furlanagro@gmail.com [Universidade de Taubate, SP (Brazil). Departamento de Ciencias Agrarias

    2013-07-01

    Melissa officinalis L., Lemon balm, (Lamiaceae) is an herb used as medicine, condiment and in the cosmetic and perfumery industry due to its essential oil. In this study a preliminary assessment of trace elements effects on essential oil production was performed in order to verify an improvement in its quality. The Melissa officinalis samples were harvested from three different soil sites localized in Ibirapuera Park, São Paulo, Brazil. Elemental concentration for the elements As, Ba, Br, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Mg, Mn, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Ti, Th, U, V, Yb, Zn and Zr was determined by Instrumental Neutron Activation Analysis (INAA) in Melissa officinalis leaves and surrounding soil. The essential oil was extracted from its leaves by hydrodistillation process in Clevenger apparatus and analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Certified reference materials NIST SRM-1515 Apple Leaves, NIST SRM-1547 Peach Leaves and NIST SRM-1573a Tomato Leaves were analyzed for quality control. Our results showed Geranial and Neral were identified as the major compounds in the essential oil extracted from Melissa officinalis L. for all collected sites. However, the relative proportion of some chemical constituents was altered according to the site collected. The preliminary results showed that the production of essential oil by Melissa officinalis must be positively correlated with the concentrations of Rb, Zn and negatively correlated with Sc, Mn, La, K, Fe, and Cr. (author)

  19. Production of interstocked 'Pera' sweet orange nursey trees on 'Volkamer' lemon and 'Swingle' citrumelo rootstocks

    Directory of Open Access Journals (Sweden)

    Girardi Eduardo Augusto

    2006-01-01

    Full Text Available Incompatibility among certain citrus scion and rootstock cultivars can be avoided through interstocking. 'Pera' sweet orange (Citrus sinensis L. Osbeck nursery tree production was evaluated on 'Swingle' citrumelo (Poncirus trifoliata (L. Raf x Citrus paradisi Macf and 'Volkamer' lemon (Citrus volkameriana Pasquale incompatible rootstocks, using 'Valencia' and 'Hamlin' sweet oranges (Citrus sinensis L. Osbeck, 'Sunki' mandarin (Citrus sunki Hort. ex Tanaka, and 'Cleopatra' mandarin (Citrus reshni Hort. ex Tanaka as interstocks. Citrus nursery trees interstocked with 'Pera' sweet orange on both rootstocks were used as control. 'Swingle' citrumelo led to the highest interstock bud take percentage, the greatest interstock height and rootstock diameter, as well as the highest scion and root system dry weight. Percentage of 'Pera' sweet orange dormant bud eye was greater for plants budded on 'Sunki' mandarin than those budded on 'Valencia' sweet orange. No symptoms of incompatibility were observed among any combinations of rootstocks, interstocks and scion. Production cycle can take up to 17 months with higher plant discard.

  20. Organic and mineral fertilization and chemical composition of lemon balm (Melissa officinalis essential oil

    Directory of Open Access Journals (Sweden)

    Ana Carolina B. Sodré

    2011-10-01

    Full Text Available Melissa officinalis L., Lamiaceae, is an herb with great growth prospects in the cosmetic industry due to its essential oil. In order to improve its production, it is necessary to study related agricultural practices. This study evaluated the effect of organic and mineral fertilization on the chemical composition of lemon balm (Melissa officinalis L. essential oil. The assay was conducted at the "Fazenda Experimental do Glória" of the Federal University of Uberlândia, and essential oil extraction and GC/MS analyses were completed by the Centre for Research and Development on Plant Genetic Resources of the Campinas Agronomic Institute. The assay was conducted in a randomized complete block design with three replications. The tested treatments were six types of fertilization (0, 1, 2, 4, 8 kg.m-2 of cattle manure and mineral fertilizing with 60 g.m-2 of NPK 4-14-8 + 4 g.m-2 of boric acid with four replications. The essential oil was extracted by hydrodistillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The essential oil presented the same compounds for all treatments; however, the relative proportion of some chemical constituents was altered according to the treatment. Neral, geranial, and citronellal were the major constituents.

  1. Organic and mineral fertilization and chemical composition of lemon balm (Melissa officinalis essential oil

    Directory of Open Access Journals (Sweden)

    Ana Carolina B. Sodré

    2012-02-01

    Full Text Available Melissa officinalis L., Lamiaceae, is an herb with great growth prospects in the cosmetic industry due to its essential oil. In order to improve its production, it is necessary to study related agricultural practices. This study evaluated the effect of organic and mineral fertilization on the chemical composition of lemon balm (Melissa officinalis L. essential oil. The assay was conducted at the "Fazenda Experimental do Glória" of the Federal University of Uberlândia, and essential oil extraction and GC/MS analyses were completed by the Centre for Research and Development on Plant Genetic Resources of the Campinas Agronomic Institute. The assay was conducted in a randomized complete block design with three replications. The tested treatments were six types of fertilization (0, 1, 2, 4, 8 kg.m-2 of cattle manure and mineral fertilizing with 60 g.m-2 of NPK 4-14-8 + 4 g.m-2 of boric acid with four replications. The essential oil was extracted by hydrodistillation in a modified Clevenger apparatus. The chemical composition was analyzed by GC/MS. The essential oil presented the same compounds for all treatments; however, the relative proportion of some chemical constituents was altered according to the treatment. Neral, geranial, and citronellal were the major constituents.

  2. Effect of citrus lemon oil on growth and adherence of Streptococcus mutans.

    Science.gov (United States)

    Liu, Ying; Zhang, Xiangyu; Wang, Yuzhi; Chen, Feifei; Yu, Zhifen; Wang, Li; Chen, Shuanglu; Guo, Maoding

    2013-07-01

    In order to exploit novel anticaries agents, we investigated the effects of citrus lemon oil (CLO), a type of natural product, on growth and adherence of the primary oral cariogenic bacteria Streptococcus mutans (S. mutans). The growth inhibitory effect was explored with a micro-dilution assay. Adherence was analyzed by colony counts on the respective surfaces and the adherence inhibition rate (AIR). Real time-PCR was used to investigate the effects of CLO on transcription of glucosyltransferase (Gtf) encoding genes, gtfB, C and D. Neson-Somogyi method was used to measure the effects of CLO on Gtf activity. The minimum inhibitory concentration of CLO against S. mutans was 4.5 mg/ml. The CLO effectively reduced the adherence of S. mutans on glass surface (the AIR were from 98.3 to 100 %, P > 0.05) and saliva-coated enamel surface (the AIR were from 54.8 to 79.2 %, P < 0.05). CLO effectively reduced the activity of Gtf and the transcription of gtfs in a dose dependent manner (P < 0.05). In conclusion, CLO can effectively inhibit the growth and the adherence to glass and saliva-coated enamel surfaces of S. mutans. It can also inhibit the transcription of gtfs, as well as the Gtf enzyme activity.

  3. A combined process to treat lemon industry wastewater and produce biogas

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, A.R.; Rubio, M.C.; Maldonado, M.C. [Quimica y Farmacia, Universidad Nacional de Tucuman, Instituto de Biotecnologia, Facultad de Bioquimica, Ayacucho, Tucuman (Argentina)

    2012-02-15

    We studied a process employed for treating lemon industry effluents, using the macrophyte Eishhornia crassipes (water hyacinth) in a phytoremediation tank with a 6000-L workload. The diluted effluents BOD and COD were reduced to 70 and 61%, respectively, working with a 1.5-h hydraulic residence time (HRT). We investigated the effect of adding every 12 h an inoculum consisting of a consortium of microorganisms isolated from the macrophyte roots and recirculating 30% of the outflow. In this way, we achieved a volumetric removal rate (VRR) of BOD = 354 g/m{sup 3} day. Plants were daily harvested from the tank to maintain growth rate and the density originally planted. We studied their use for biogas production in an anaerobic digester working with 12 and 16 days of hydraulic residence time. The yield obtained was 0.87 L/g and productivity 0.87 L/L day with a loading rate of 5 g/L day. Integrating both processes on an industrial scale would solve the effluent pollution problem and generate an energy source that could be used by the industry itself to lower its production costs. (orig.)

  4. Shark, new motor design concept for energy saving applied to switched reluctance motor

    Energy Technology Data Exchange (ETDEWEB)

    Tataru Kjaer, A.M.

    2005-07-01

    The aim of this thesis is to document and promote a relatively new concept of designing electrical machine with improved efficiency, without using more or better material. The concept, called Shark, consists in replacing the cylindrical air gap by a non-linear shape obtained by translating specific geometrical pattern on the longitudinal axis of the electrical machine. This shape modification increases the air gap area and thus the energy conversion, taking place in the machine. Whilst other methods of improving the efficiency consider the use of more and/or better magnetic material and/or optimisation of the magnetic circuit of the radial cross-section of the machine, the proposed method makes use of the longitudinal cross-section of the machine. In spite of a few reports claiming the improvement of the efficiency by applying the optimisation of the longitudinal cross-section, none analysis of various air gap shapes and of their influence on the magnetic performance has been reported. Due to a simple geometry, the Switched Reluctance Machine has been selected for demonstration of the Shark principle. Initially, linear and finite element analyses are considered. They provide the basic knowledge of the manner in which various Shark air gap, having different dimensions, influence the energy conversion in the machine. The saturation mechanisms, specific to each Shark profile are analysed and optimum Shark profile and its dimensions are selected for implementation in a demonstration machine. Due to the lack of quick analysis tools, an analytical model of the Shark Switched Reluctance Machine is also proposed in this thesis. This model is conceived by modifying one of the existing models of cylindrical air gap Switched Reluctance Machines, such as to account for the presence of the Shark profiles in the air gap. The calculations are verified by measurement on two demonstration machines, having cylindrical and Shark air gaps. The measurement proved the theory right and

  5. Basking Shark (Cetorhinus maximus Movements in the Eastern North Pacific Determined Using Satellite Telemetry

    Directory of Open Access Journals (Sweden)

    Heidi Dewar

    2018-05-01

    Full Text Available To fill data gaps on movements, behaviors and habitat use, both near- and offshore, two programs were initiated to deploy satellite tags on basking sharks off the coast of California. Basking sharks are large filter-feeding sharks that are second in size only to whale sharks. Similar to many megafauna populations, available data suggest that populations are below historic levels. In the eastern North Pacific (ENP Ocean, the limited information on basking sharks comes from nearshore habitats where they forage. From 2010 to 2011, four sharks were tagged with pop-off satellite archival tags with deployments ranging from 9 to 240 days. The tags provided both transmitted and archived data on habitat use and geographic movement patterns. Nearshore, sharks tended to move north in the summer and prefer shelf and slope habitat around San Diego, Point Conception and Monterey Bay. The two sharks with 180 and 240 days deployments left the coast in the summer and fall. Offshore their paths diverged and by January one shark had moved to near the tip of the Baja Peninsula, Mexico and the other to the waters near Hawaii, USA. Vertical habitat use was variable both within and among individuals and changed as sharks moved offshore. Nearshore, most time was spent in the mixed layer but sharks did spend hours in cold waters below the mixed layer. Offshore vertical movements depended on location. The shark that went to Hawaii had a distinct diel pattern, with days spent at ~450–470 m and nights at ~250–300 m and almost no time in surface waters, corresponding with the diel migration of a specific portion of the deep scattering layer. The shark that moved south along the Baja Peninsula spent progressively more time in deep water but came to the surface daily. Movement patterns and shifts in vertical habitat and use are likely linked to shifts in prey availability and oceanography. Data collected indicate the potential for large-scale movements and the need for

  6. [Effect of variation of lemon intake and walking in daily life on various indicators of muscle mass and blood biochemistry in menopausal middle-aged and elderly women].

    Science.gov (United States)

    Sato, Kimiko; Domoto, Tokio; Hiramitsu, Masanori; Katagiri, Takao; Kato, Yoji; Miyake, Yukiko; Ishihara, Katsuhide; Umei, Namiko; Takigawa, Atsushi; Harada, Toshihide; Aoi, Satomi; Ikeda, Hiromi

    2014-01-01

    We examined the factors considered to change body composition and blood biochemistry indicators in menopausal middle-aged and elderly women. These changes result from exercise by walking as part of their daily activities and lemon consumption by women who live on the small islands of the Seto Inland Sea, Japan's largest citrus fruit (lemon)-producing region. Between September 2011 and March 2012, we recorded the daily lemon consumption and the number of steps taken by 101 middle-aged and elderly female lemon farmers. We also measured their body dimensions, body compositions, and blood pressure pulse wave velocity and conducted blood tests before and after the survey period. The results before and after the survey period were compared by the t-test and associations were determined on the basis of Pearson's correlation coefficient. Covariance structural analysis was carried out to determine causal associations. From the results of covariance structure analysis, lemon intake did not have a direct impact on each item examined. The third item, i.e., "the factors related to arteriosclerosis," was affected indirectly via citric acid and fatigue, and anticoagulation was shown. The fourth item, i.e., "the factors related to maintenance of muscle mass," which is affected by menopausal years and the change in walking speed, was shown to be associated with the second item, i.e., "the factors related to lipid metabolism." Menopausal years affected the first, third and fourth items. Lemon intake did not have a direct impact on each item. Lemon has been shown to indirectly affect the third item through citric acid. Walking affected the second item, the level of total cholesterol, such as HDL cholesterol, through the fourth item. The importance of providing services that lead to sustained physical activity and a well-balanced metabolism between lipids and carbohydrates has been shown.

  7. Mechanical challenges to freshwater residency in sharks and rays.

    Science.gov (United States)

    Gleiss, Adrian C; Potvin, Jean; Keleher, James J; Whitty, Jeff M; Morgan, David L; Goldbogen, Jeremy A

    2015-04-01

    Major transitions between marine and freshwater habitats are relatively infrequent, primarily as a result of major physiological and ecological challenges. Few species of cartilaginous fish have evolved to occupy freshwater habitats. Current thought suggests that the metabolic physiology of sharks has remained a barrier to the diversification of this taxon in freshwater ecosystems. Here, we demonstrate that the physical properties of water provide an additional constraint for this species-rich group to occupy freshwater systems. Using hydromechanical modeling, we show that occurrence in fresh water results in a two- to three-fold increase in negative buoyancy for sharks and rays. This carries the energetic cost of lift production and results in increased buoyancy-dependent mechanical power requirements for swimming and increased optimal swim speeds. The primary source of buoyancy, the lipid-rich liver, offers only limited compensation for increased negative buoyancy as a result of decreasing water density; maintaining the same submerged weight would involve increasing the liver volume by very large amounts: 3- to 4-fold in scenarios where liver density is also reduced to currently observed minimal levels and 8-fold without any changes in liver density. The first data on body density from two species of elasmobranch occurring in freshwater (the bull shark Carcharhinus leucas, Müller and Henle 1839, and the largetooth sawfish Pristis pristis, Linnaeus 1758) support this hypothesis, showing similar liver sizes as marine forms but lower liver densities, but the greatest negative buoyancies of any elasmobranch studied to date. Our data suggest that the mechanical challenges associated with buoyancy control may have hampered the invasion of freshwater habitats in elasmobranchs, highlighting an additional key factor that may govern the predisposition of marine organisms to successfully establish in freshwater habitats. © 2015. Published by The Company of Biologists Ltd.

  8. Ongoing decline of shark populations in the Eastern Red Sea

    KAUST Repository

    Spaet, Julia L.Y.

    2016-06-30

    Information on the abundance and diversity of Red Sea elasmobranchs is notoriously scarce, even though sharks are among the most profitable fisheries of the region. Effective conservation would ideally entail baselines on pristine conditions, yet no such data is available for the Red Sea. To collect distribution and abundance data on Red Sea elasmobranchs, we conducted a dedicated longline and Baited Remote Underwater Video system (BRUVs) sampling program along the entire Red Sea coast of Saudi Arabia over the course of two years. Both survey techniques were opportunistically employed at central and southern Saudi Arabian (SA) Red Sea reef systems. In addition, BRUVs were employed in the northern SA Red Sea and at selected reef systems in Sudan. Shark catch per unit effort (CPUE) data for BRUVs and longline surveys were compared to published data from non-Red Sea reef systems. This comparison revealed CPUE estimates several orders of magnitude lower for both survey methods in the SA Red Sea compared to other reef systems around the world. Catch per unit effort values of BRUVs on Sudanese reefs on the contrary were within the range of estimates from various locations where sharks are considered common. We argue that decades of heavy fishing pressure on Red Sea marine resources has significantly altered the community structure of SA Red Sea reefs. There is an urgent need to establish effective management strategies for species of highest conservation concern. Our results have the potential to be used as a baseline, if such management strategies were to be established. © 2016 Elsevier Ltd

  9. Mechanics of biting in great white and sandtiger sharks.

    Science.gov (United States)

    Ferrara, T L; Clausen, P; Huber, D R; McHenry, C R; Peddemors, V; Wroe, S

    2011-02-03

    Although a strong correlation between jaw mechanics and prey selection has been demonstrated in bony fishes (Osteichthyes), how jaw mechanics influence feeding performance in cartilaginous fishes (Chondrichthyes) remains unknown. Hence, tooth shape has been regarded as a primary predictor of feeding behavior in sharks. Here we apply Finite Element Analysis (FEA) to examine form and function in the jaws of two threatened shark species, the great white (Carcharodon carcharias) and the sandtiger (Carcharias taurus). These species possess characteristic tooth shapes believed to reflect dietary preferences. We show that the jaws of sandtigers and great whites are adapted for rapid closure and generation of maximum bite force, respectively, and that these functional differences are consistent with diet and dentition. Our results suggest that in both taxa, insertion of jaw adductor muscles on a central tendon functions to straighten and sustain muscle fibers to nearly orthogonal insertion angles as the mouth opens. We argue that this jaw muscle arrangement allows high bite forces to be maintained across a wider range of gape angles than observed in mammalian models. Finally, our data suggest that the jaws of sub-adult great whites are mechanically vulnerable when handling large prey. In addition to ontogenetic changes in dentition, further mineralization of the jaws may be required to effectively feed on marine mammals. Our study is the first comparative FEA of the jaws for any fish species. Results highlight the potential of FEA for testing previously intractable questions regarding feeding mechanisms in sharks and other vertebrates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. A multiplex PCR mini-barcode assay to identify processed shark products in the global trade.

    Directory of Open Access Journals (Sweden)

    Diego Cardeñosa

    Full Text Available Protecting sharks from overexploitation has become global priority after widespread population declines have occurred. Tracking catches and trade on a species-specific basis has proven challenging, in part due to difficulties in identifying processed shark products such as fins, meat, and liver oil. This has hindered efforts to implement regulations aimed at promoting sustainable use of commercially important species and protection of imperiled species. Genetic approaches to identify shark products exist but are typically based on sequencing or amplifying large DNA regions and may fail to work on heavily processed products in which DNA is degraded. Here, we describe a novel multiplex PCR mini-barcode assay based on two short fragments of the cytochrome oxidase I (COI gene. This assay can identify to species all sharks currently listed on the Convention of International Trade of Endangered Species (CITES and most shark species present in the international trade. It achieves species diagnosis based on a single PCR and one to two downstream DNA sequencing reactions. The assay is capable of identifying highly processed shark products including fins, cooked shark fin soup, and skin-care products containing liver oil. This is a straightforward and reliable identification method for data collection and enforcement of regulations implemented for certain species at all governance levels.

  11. Variations in gastric acid secretion during periods of fasting between two species of shark.

    Science.gov (United States)

    Papastamatiou, Yannis P; Lowe, Christopher G

    2005-06-01

    Vertebrates differ in their regulation of gastric acid secretion during periods of fasting, yet it is unknown why these differences occur. Elasmobranch fishes are the earliest known vertebrates to develop an acid secreting stomach and as such may make a good comparative model for determining the causative factors behind these differences. We measured gastric pH and temperature continuously during periods of fasting in captive free-swimming nurse sharks (Ginglymostoma cirratum) using autonomous pH/temperature data-loggers. All nurse sharks secreted strong gastric acids (minimum pH 0.4) after feeding; however, for most of the sharks, pH increased to 8.2-8.7, 2-3 days after feeding. Half of the sharks also exhibited periodic oscillations in pH when the stomach was empty that ranged from 1.1 to 8.7 (acid secretion ceased for 11.3 +/- 4.3 h day(-1)). This is in contrast to the gastric pH changes observed from leopard sharks (Triakis semifasciata) in a previous study, where the stomach remains acidic during fasting. The leopard shark is a relatively active, more frequently feeding predator, and continuous acid secretion may increase digestive efficiency. In contrast, the nurse shark is less active and is thought to feed less frequently. Periodic cessation of acid secretion may be an energy conserving mechanism used by animals that feed infrequently and experience extended periods of fasting.

  12. Cyanobacterial Neurotoxin β-N-Methylamino-L-alanine (BMAA in Shark Fins

    Directory of Open Access Journals (Sweden)

    John Pablo

    2012-02-01

    Full Text Available Sharks are among the most threatened groups of marine species. Populations are declining globally to support the growing demand for shark fin soup. Sharks are known to bioaccumulate toxins that may pose health risks to consumers of shark products. The feeding habits of sharks are varied, including fish, mammals, crustaceans and plankton. The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA has been detected in species of free-living marine cyanobacteria and may bioaccumulate in the marine food web. In this study, we sampled fin clips from seven different species of sharks in South Florida to survey the occurrence of BMAA using HPLC-FD and Triple Quadrupole LC/MS/MS methods. BMAA was detected in the fins of all species examined with concentrations ranging from 144 to 1836 ng/mg wet weight. Since BMAA has been linked to neurodegenerative diseases, these results may have important relevance to human health. We suggest that consumption of shark fins may increase the risk for human exposure to the cyanobacterial neurotoxin BMAA.

  13. Evidence of Maternal Offloading of Organic Contaminants in White Sharks (Carcharodon carcharias)

    Science.gov (United States)

    Mull, Christopher G.; Lyons, Kady; Blasius, Mary E.; Winkler, Chuck; O’Sullivan, John B.; Lowe, Christopher G.

    2013-01-01

    Organic contaminants were measured in young of the year (YOY) white sharks (Carcharodon carcharias) incidentally caught in southern California between 2005 and 2012 (n = 20) and were found to be unexpectedly high considering the young age and dietary preferences of young white sharks, suggesting these levels may be due to exposure in utero. To assess the potential contributions of dietary exposure to the observed levels, a five-parameter bioaccumulation model was used to estimate the total loads a newborn shark would potentially accumulate in one year from consuming contaminated prey from southern California. Maximum simulated dietary accumulation of DDTs and PCBs were 25.1 and 4.73 µg/g wet weight (ww) liver, respectively. Observed ΣDDT and ΣPCB concentrations (95±91 µg/g and 16±10 µg/g ww, respectively) in a majority of YOY sharks were substantially higher than the model predictions suggesting an additional source of contaminant exposure beyond foraging. Maternal offloading of organic contaminants during reproduction has been noted in other apex predators, but this is the first evidence of transfer in a matrotrophic shark. While there are signs of white shark population recovery in the eastern Pacific, the long-term physiological and population level consequences of biomagnification and maternal offloading of environmental contaminants in white sharks is unclear. PMID:23646154

  14. Biological aspects of sharks caught off the Coast of Pernambuco, Northeast Brazil

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    AF. Fischer

    Full Text Available One hundred seventeen specimens of sharks were caught along the coast of Pernambuco State, Northern Brazil, between May 2004 and May 2007, among which 86 were blacknose sharks, Carcharhinus acronotus, enabling a more detailed study of the species. Blacknose sharks were caught in the 2 study areas along the Boa Viagem/Piedade and Paiva beaches, accounting for the highest relative abundance among the species caught (73.5% of total. Potentially dangerous sharks, tiger and bull sharks, were also caught in the same areas, whereas hammerhead and blacktip sharks were only captured off Boa Viagem/Piedade. Concerning the blacknose shark, the total length (TL ranged from 39.0 to 180.0 cm. Among the 38 females analysed, 32 were juveniles, 11 were maturing, 2 were pre-ovulatory and 21 were pregnant. Sexing was possible for 75 of the 83 embryos, 38 of which were males and 37 were females, with a sex proportion of 1:0.9 and total length ranging between 6.4 and 63.5 cm. Ovarian fecundity ranged from 5 to 10 and uterine fecundity from 1 to 3, with an estimated gestational period of 9 months. Among the 48 males, 6 were juveniles and 42 were adults. Both males and females seem to reach sexual maturity at about 105.0 cm TL. Among the 86 stomachs analysed, only 22.1% had contents, with teleosts as the most frequent item.

  15. Local ecological knowledge of artisanal fishermen in southern Bahia, Brazil, about trophic interactions of sharks

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    Márcio Luiz Vargas Barbosa Filho

    2016-09-01

    Full Text Available Despite the serious threats that affect shark species living along the central coast of Brazil, knowledge about the life history of these animals is still scarce. The present study describes the knowledge and perceptions of fishermen from southern Bahia, Brazil, on the trophic interactions of sharks. The objective of this work was to generate information that contributes to a better understanding of the life history of sharks from this poorly known region. In 2012, semi-structured interviews were conducted with 65 fishermen, with over 15 years of experience, about fisheries and aspects of shark feeding behavior. The study found that the participants have comprehensive ethno-ecological knowledge about shark feeding habits, describing 39 types of items as components of the diets of these animals. They are also able to recognize the favored items in the diet of each ethnospecies of shark. Similar studies about shark feeding habits along the Brazilian coast should be developed. This will generate more detailed knowledge and/or new scientific hypotheses about the interspecific relationships of these predators and their prey.

  16. Effects of fasting and refeeding on intestinal cell proliferation and apoptosis in hammerhead shark (Sphyrna lewini

    Directory of Open Access Journals (Sweden)

    Hideya Takahashi

    2014-04-01

    Full Text Available Objective: To examine the effects of fasting and refeeding on intestinal cell proliferation and apoptosis in an opportunistic predator, hammerhead shark (Sphyrna lewini of elasmobranch fishes which are among the earliest known extant groups of vertebrates to have the valvular intestine typical for the primitive species. Methods: Animals were euthanized after 5-10 d of fasting or feeding, or after 10-day fasting and 5-day refeeding. Intestinal apoptosis and cell proliferation were assessed by using oligonucleotide detection assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and immunohistochemistry of proliferating cells nuclear antigen. Results: Plasma levels of cholesterol and glucose were reduced by fasting. Intestinal apoptosis generally decreased during fasting. Numerous apoptotic cells were observed around the tips of the villi, primarily in the epithelium in the fed sharks, whereas fewer labeled nuclei were detected in the epithelium of fasted sharks. Refeeding returned intestinal apoptosis to the level in the fed sharks. Proliferating cells were observed in the epithelium around the troughs of the villi and greater in number in fed sharks, whereas fewer labeled nuclei were detected in fasted sharks. Conclusions: The cell turnover is modified in both intestinal epithelia of the shark and the murines by fasting/feeding, but in opposite directions. The difference may reflect the feeding ecology of the elasmobranchs, primitive intermittent feeders.

  17. The peripheral olfactory organ in the Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801

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    Laura Ghigliotti

    2015-11-01

    Full Text Available The Greenland shark Somniosus microcephalus (Bloch and Schneider, 1801 is the largest predatory fish in Arctic waters. The socio-economic significance of Greenland shark is demonstrated by its impact on the fishing cultures in Greenland, Scandinavia and Iceland for centuries. The fundamental biology and ecological role of Greenland shark, on the other hand, is virtually unknown. Although knowledge of its life history is limited, increasing evidence indicates that the Greenland shark may undertake long-distance migrations and perform vertical movements from the surface to the deep sea. It is an omnivorous species feeding on carrion and a wide variety of pelagic and bottom-dwelling organisms ranging from invertebrates to mammals, and including active species such as fishes and seals. Accordingly, Greenland shark should be recognized as a top predator, with a strong potential to influence the trophic dynamics of the Arctic marine ecosystem. The sensory biology of Greenland shark is scarcely studied, and considering the importance of olfaction in chemoreception, feeding and other behavioral traits, we examined the architecture of the peripheral olfactory organ where olfactory cues are received from the environment – the olfactory rosette. The structural organization of the olfactory rosette, in terms of histological features of the sensory epithelium, number of primary lamellae and total sensory surface area, provides a first proxy of the olfactory capability of Greenland shark. Based on own results and published studies, the overall morphology of the olfactory rosette is viewed in context of the functional and trophic ecology among other elasmobranch species.

  18. Annually recurring parthenogenesis in a zebra shark Stegostoma fasciatum.

    Science.gov (United States)

    Robinson, D P; Baverstock, W; Al-Jaru, A; Hyland, K; Khazanehdari, K A

    2011-11-01

    A zebra shark, Stegostoma fasciatum, held in captivity at the Burj Al Arab aquarium, produced embryos and pups in the absence of a male. A total of 15 pups were produced from eggs laid within the aquarium over a period of four consecutive years commencing 2007. Parthenogenesis was confirmed through DNA analysis for three pups sampled during the first two consecutive egg cycles and is presumed to be the method of reproduction responsible thereafter. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  19. Exoemission and thermoluminescence from human enamel and shark enameloid

    International Nuclear Information System (INIS)

    Davies, J.E.

    1983-01-01

    Simultaneous measurements of exoelectron emission and thermoluminescence from powdered biological apatites, which have not been chemically or thermally pretreated, are reported. Recycling, that is, consecutive irradiation and non-isothermal scanning, is shown to change both the form of the glow curves and emissivity of samples. Two biological apatites of the hydroxyapatite type (human enamel) and fluorapatite type (shark enameloid) are compared. Although their initial glow curves are different, recycling renders the glow curves similar suggesting that the defects involved are a product of the host lattice. The relevance of exoemission as a ''fingerprinting'' technique for biologically reactive material is discussed. (author)

  20. Biological observations on the broadfin shark Lamiopsis temminckii (Carcharhiniformes: Carcharhinidae).

    Science.gov (United States)

    Akhilesh, K V; Purushottama, G B; Thakurdas; Kizhakudan, S J

    2017-12-01

    Biological information was collected from 214 individuals of the broadfin shark Lamiopsis temminckii measuring 418 to 1782 mm total length, L T . Size at maturity (L 50 ) for females and males was estimated at 1430 and 1368 mm L T , respectively, while mature and gravid females were observed from 1350 mm L T with litter sizes 2-8 and size at birth 418-650 mm L T . Analysis of stomach contents revealed a variety of prey, primarily crustaceans (54·0%), teleosts (42·7%) and cephalopods. © 2017 The Fisheries Society of the British Isles.

  1. Complete mitogenome of the Graceful Shark Carcharhinus amblyrhynchoides (Carcharhiniformes: Carcharhinidae).

    Science.gov (United States)

    Feutry, Pierre; Pillans, Richard D; Kyne, Peter M; Chen, Xiao

    2016-01-01

    In this manuscript we describe the first complete mitochondrial sequence for the Near Threatened Graceful Shark Carcharhinus amblyrhynchoides. It is 16,705 bp in length, consists of two rRNA genes, 22 tRNA genes, 13 protein-coding genes and one control region with the typical gene arrangement pattern and translate orientation in vertebrates. The overall base composition is 31.4% A, 25.1% C, 13.2% G and 30.3% T. The shortest tRNA-Ser2 cannot fold into a clover-leaf secondary structure due to the lack of the dihydrouridine arm.

  2. Structure and dynamics of the shark assemblage off Recife, Northeastern Brazil.

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    André S Afonso

    Full Text Available Understanding the ecological factors that regulate elasmobranch abundance in nearshore waters is essential to effectively manage coastal ecosystems and promote conservation. However, little is known about elasmobranch populations in the western South Atlantic Ocean. An 8-year, standardized longline and drumline survey conducted in nearshore waters off Recife, northeastern Brazil, allowed us to describe the shark assemblage and to monitor abundance dynamics using zero-inflated generalized additive models. This region is mostly used by several carcharhinids and one ginglymostomid, but sphyrnids are also present. Blacknose sharks, Carcharhinus acronotus, were mostly mature individuals and declined in abundance throughout the survey, contrasting with nurse sharks, Ginglymostoma cirratum, which proliferated possibly due to this species being prohibited from all harvest since 2004 in this region. Tiger sharks, Galeocerdo cuvier, were mostly juveniles smaller than 200 cm and seem to use nearshore waters off Recife between January and September. No long-term trend in tiger shark abundance was discernible. Spatial distribution was similar in true coastal species (i.e. blacknose and nurse sharks whereas tiger sharks were most abundant at the middle continental shelf. The sea surface temperature, tidal amplitude, wind direction, water turbidity, and pluviosity were all selected to predict shark abundance off Recife. Interspecific variability in abundance dynamics across spatiotemporal and environmental gradients suggest that the ecological processes regulating shark abundance are generally independent between species, which could add complexity to multi-species fisheries management frameworks. Yet, further research is warranted to ascertain trends at population levels in the South Atlantic Ocean.

  3. Early-life exposure to climate change impairs tropical shark survival.

    Science.gov (United States)

    Rosa, Rui; Baptista, Miguel; Lopes, Vanessa M; Pegado, Maria Rita; Paula, José Ricardo; Trübenbach, Katja; Leal, Miguel Costa; Calado, Ricardo; Repolho, Tiago

    2014-10-22

    Sharks are one of the most threatened groups of marine animals worldwide, mostly owing to overfishing and habitat degradation/loss. Although these cartilaginous fish have evolved to fill many ecological niches across a wide range of habitats, they have limited capability to rapidly adapt to human-induced changes in their environments. Contrary to global warming, ocean acidification was not considered as a direct climate-related threat to sharks. Here we show, for the first time, that an early ontogenetic acclimation process of a tropical shark (Chiloscyllium punctatum) to the projected scenarios of ocean acidification (ΔpH = 0.5) and warming (+4°C; 30°C) for 2100 elicited significant impairments on juvenile shark condition and survival. The mortality of shark embryos at the present-day thermal scenarios was 0% both at normocapnic and hypercapnic conditions. Yet routine metabolic rates (RMRs) were significantly affected by temperature, pH and embryonic stage. Immediately after hatching, the Fulton condition of juvenile bamboo sharks was significantly different in individuals that experienced future warming and hypercapnia; 30 days after hatching, survival rapidly declined in individuals experiencing both ocean warming and acidification (up to 44%). The RMR of juvenile sharks was also significantly affected by temperature and pH. The impact of low pH on ventilation rates was significant only under the higher thermal scenario. This study highlights the need of experimental-based risk assessments of sharks to climate change. In other words, it is critical to directly assess risk and vulnerability of sharks to ocean acidification and warming, and such effort can ultimately help managers and policy-makers to take proactive measures targeting most endangered species. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  4. The last frontier: catch records of white sharks (Carcharodon carcharias) in the Northwest Pacific Ocean.

    Science.gov (United States)

    Christiansen, Heather M; Lin, Victor; Tanaka, Sho; Velikanov, Anatoly; Mollet, Henry F; Wintner, Sabine P; Fordham, Sonja V; Fisk, Aaron T; Hussey, Nigel E

    2014-01-01

    White sharks are highly migratory apex predators, globally distributed in temperate, sub-tropical, and tropical waters. Knowledge of white shark biology and ecology has increased recently based on research at known aggregation sites in the Indian, Atlantic, and Northeast Pacific Oceans; however, few data are available for the Northwest Pacific Ocean. This study provides a meta-analysis of 240 observations of white sharks from the Northwest Pacific Ocean between 1951 and 2012. Records comprise reports of bycatch in commercial fisheries, media accounts, personal communications, and documentation of shark-human interactions from Russia (n = 8), Republic of Korea (22), Japan (129), China (32), Taiwan (45), Philippines (1) and Vietnam (3). Observations occurred in all months, excluding October-January in the north (Russia and Republic of Korea) and July-August in the south (China, Taiwan, Philippines, and Vietnam). Population trend analysis indicated that the relative abundance of white sharks in the region has remained relatively stable, but parameterization of a 75% increase in observer effort found evidence of a minor decline since 2002. Reliably measured sharks ranged from 126-602 cm total length (TL) and 16-2530 kg total weight. The largest shark in this study (602 cm TL) represents the largest measured shark on record worldwide. For all countries combined the sex ratio was non-significantly biased towards females (1∶1.1; n = 113). Of 60 females examined, 11 were confirmed pregnant ranging from the beginning stages of pregnancy (egg cases) to near term (140 cm TL embryos). On average, 6.0±2.2 embryos were found per litter (maximum of 10) and gestation period was estimated to be 20 months. These observations confirm that white sharks are present in the Northwest Pacific Ocean year-round. While acknowledging the difficulties of studying little known populations of a naturally low abundance species, these results highlight the need for dedicated research to

  5. Characterization of Novel Whale Shark Aggregations at Shib Habil, Saudi Arabia and Mafia Island, Tanzania

    KAUST Repository

    Cochran, Jesse

    2014-12-01

    Passive acoustic monitoring has been successfully used on many elasmobranch species, but no such study has yet been published for the whale shark (Rhincodon typus). In some ways this is surprising as the known whale shark aggregation sites would seem to be ideal targets for this method. For this dissertation, two acoustic studies were carried out in Saudi Arabia and Tanzania. Each was performed in parallel with visual surveys and the Saudi population was also studied using satellite telemetry. Sighting and acoustic data were compared at both sites, and the results were mixed. The acoustic monitoring largely confirmed the results of visual surveys for the Saudi Arabian sharks, including seasonality, residency and a degree of parity and integration between the sexes that is unique to this site. Satellite tracks of tagged Saudi sharks were used to confirm that some animals migrated away from the aggregation site before returning in subsequent seasons, confirming philopatric behavior in this species. In contrast, the acoustic results in Tanzania demonstrated year-round residency of whale sharks in the area, despite seasonal declines in visually estimated abundance. Seasonal changes in habitat selection render the sharks at this site temporarily cryptic to visual sampling. The differing results are compelling because both the philopatric behavior demonstrated in Saudi Arabia and the cryptic residency of the Tanzanian sharks could explain the seasonal patterns in whale shark abundances reported at other aggregation sites. Despite their differences, both sites in this study can be classified as secondary whale shark nurseries and each may be a vital feeding ground for its respective population.

  6. Tiger sharks can connect equatorial habitats and fisheries across the Atlantic Ocean basin.

    Directory of Open Access Journals (Sweden)

    André S Afonso

    Full Text Available Increasing our knowledge about the spatial ecology of apex predators and their interactions with diverse habitats and fisheries is necessary for understanding the trophic mechanisms that underlie several aspects of marine ecosystem dynamics and for guiding informed management policies. A preliminary assessment of tiger shark (Galeocerdo cuvier population structure off the oceanic insular system of Fernando de Noronha (FEN and the large-scale movements performed by this species in the equatorial Atlantic Ocean was conducted using longline and handline fishing gear and satellite telemetry. A total of 25 sharks measuring 175-372 cm in total length (TL were sampled. Most sharks were likely immature females ranging between 200 and 260 cm TL, with few individuals < 200 cm TL being caught. This contrasts greatly with the tiger shark size-distribution previously reported for coastal waters off the Brazilian mainland, where most individuals measured < 200 cm TL. Also, the movements of 8 individuals measuring 202-310 cm TL were assessed with satellite transmitters for a combined total of 757 days (mean = 94.6 days∙shark-1; SD = 65.6. These sharks exhibited a considerable variability in their horizontal movements, with three sharks showing a mostly resident behavior around FEN during the extent of the respective tracks, two sharks traveling west to the South American continent, and two sharks moving mostly along the middle of the oceanic basin, one of which ending up in the northern hemisphere. Moreover, one shark traveled east to the African continent, where it was eventually caught by fishers from Ivory Coast in less than 474 days at liberty. The present results suggest that young tiger sharks measuring < 200 cm TL make little use of insular oceanic habitats from the western South Atlantic Ocean, which agrees with a previously-hypothesized ontogenetic habitat shift from coastal to oceanic habitats experienced by juveniles of this species in this region

  7. Extracting DNA from 'jaws': High yield and quality from archived tiger shark (Galeocerdo cuvier) skeletal material

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Morgan, J. A T; Maher, S. L.

    2017-01-01

    of tiger sharks (Galeocerdo cuvier). Protocols were compared for DNA yield and quality using a qPCR approach. For jaw swarf, all methods provided relatively high DNA yield and quality, while large differences in yield between protocols were observed for vertebrae. Similar results were obtained from samples...... observed, likely reflecting different preparation and storage methods for the trophies. Trial sequencing of DNA capture genomic libraries using 20 000 baits revealed that a significant proportion of captured sequences were derived from tiger sharks. This study demonstrates that archived shark jaws...

  8. Historical and contemporary records of the angular rough shark Oxynotus centrina (Chondrichthyes; Oxynotidae in Turkish waters

    Directory of Open Access Journals (Sweden)

    H. KABASAKAL

    2010-10-01

    Full Text Available During the last 58 years, only 12 angular rough sharks were recorded in Turkish waters. Rare captures of the species in the area needs an immediate action for the conservation of O. centrina. To protect the habitat of O. centrina, strict regulations should be implemented for diving in the localities, where the angular rough sharks occur regularly. Protecting the habitat of the angular rough shark is an urgent need before subjecting O. centrina to 100% protection in the seas of Turkey.

  9. Persistent organochlorines in 13 shark species from offshore and coastal waters of Korea: Species-specific accumulation and contributing factors.

    Science.gov (United States)

    Lee, Hyun-Kyung; Jeong, Yunsun; Lee, Sunggyu; Jeong, Woochang; Choy, Eun-Jung; Kang, Chang-Keun; Lee, Won-Chan; Kim, Sang-Jo; Moon, Hyo-Bang

    2015-05-01

    Data on persistent organochlorines (OCs) in sharks are scarce. Concentrations of OCs such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in the muscle tissue of 13 shark species (n=105) collected from offshore (Indian and Pacific Oceans) and coastal waters of Korea, to investigate species-specific accumulation of OCs and to assess the potential health risks associated with consumption of shark meat. Overall OC concentrations were highly variable not only among species but also within the same species of shark. The concentrations of PCBs, DDTs, chlordanes, hexachlorobenzene, and heptachlor in all shark species ranged from shark in our study were relatively lower than those reported in other studies. Aggressive shark species and species inhabiting the Indian Ocean had the highest levels of OCs. Inter-species differences in the concentrations and accumulation profiles of OCs among shark species could be explained by differences in feeding habit and sampling locations. Several confounding factors such as growth velocity, trophic position, and regional contamination status may affect the bioaccumulation of OCs in sharks. Hazard ratios of non-cancer risk for all the OCs were below one, whereas the hazard ratios of lifetime cancer risks of PCBs and DDTs exceeded one, implying potential carcinogenic effects in the general population in Korea. This is the first report to document the occurrence of OCs in sharks from Korea. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Characterization of shark complement factor I gene(s): genomic analysis of a novel shark-specific sequence.

    Science.gov (United States)

    Shin, Dong-Ho; Webb, Barbara M; Nakao, Miki; Smith, Sylvia L

    2009-07-01

    Complement factor I is a crucial regulator of mammalian complement activity. Very little is known of complement regulators in non-mammalian species. We isolated and sequenced four highly similar complement factor I cDNAs from the liver of the nurse shark (Ginglymostoma cirratum), designated as GcIf-1, GcIf-2, GcIf-3 and GcIf-4 (previously referred to as nsFI-a, -b, -c and -d) which encode 689, 673, 673 and 657 amino acid residues, respectively. They share 95% (shark-specific sequence between the leader peptide (LP) and the factor I membrane attack complex (FIMAC) domain. The cDNA sequences differ only in the size and composition of the shark-specific region (SSR). Sequence analysis of each SSR has identified within the region two novel short sequences (SS1 and SS2) and three repeat sequences (RS1-3). Genomic analysis has revealed the existence of three introns between the leader peptide and the FIMAC domain, tentatively designated intron 1, intron 2, and intron 3 which span 4067, 2293 and 2082bp, respectively. Southern blot analysis suggests the presence of a single gene copy for each cDNA type. Phylogenetic analysis suggests that complement factor I of cartilaginous fish diverged prior to the emergence of mammals. All four GcIf cDNA species are expressed in four different tissues and the liver is the main tissue in which expression level of all four is high. This suggests that the expression of GcIf isotypes is tissue-dependent.

  11. How great white sharks nourish their embryos to a large size: evidence of lipid histotrophy in lamnoid shark reproduction.

    Science.gov (United States)

    Sato, Keiichi; Nakamura, Masaru; Tomita, Taketeru; Toda, Minoru; Miyamoto, Kei; Nozu, Ryo

    2016-09-15

    The great white shark (Carcharodon carcharias) exhibits viviparous and oophagous reproduction. A 4950 mm total length (TL) gravid female accidentally caught by fishermen in the Okinawa Prefecture, Southern Japan carried six embryos (543-624 mm TL, three in each uterus). Both uteri contained copious amounts of yellowish viscous uterine fluid (over 79.2 litres in the left uterus), nutrient eggs and broken egg cases. The embryos had yolk stomachs that had ruptured, the mean volume of which was approximately 197.9 ml. Embryos had about 20 rows of potentially functional teeth in the upper and lower jaws. Periodic acid Schiff (PAS)-positive substances were observed on the surface and in the cytoplasm of the epithelial cells, and large, secretory, OsO4-oxidized lipid droplets of various sizes were distributed on the surface of the villous string epithelium on the uterine wall. Histological examination of the uterine wall showed it to consist of villi, similar to the trophonemata of Dasyatidae rays, suggesting that the large amount of fluid found in the uterus of the white shark was likely required for embryo nutrition. We conclude that: (1) the lipid-rich fluid is secreted from the uterine epithelium only in early gestation before the onset of oophagy, (2) the embryos probably use the abundant uterine fluid and encased nutrient eggs for nutrition at this stage of their development, and (3) the uterine fluid is the major source of embryonic nutrition before oophagy onset. This is the first record of the lipid histotrophy of reproduction among all shark species. © 2016. Published by The Company of Biologists Ltd.

  12. How great white sharks nourish their embryos to a large size: evidence of lipid histotrophy in lamnoid shark reproduction

    Directory of Open Access Journals (Sweden)

    Keiichi Sato

    2016-09-01

    Full Text Available The great white shark (Carcharodon carcharias exhibits viviparous and oophagous reproduction. A 4950 mm total length (TL gravid female accidentally caught by fishermen in the Okinawa Prefecture, Southern Japan carried six embryos (543-624 mm TL, three in each uterus. Both uteri contained copious amounts of yellowish viscous uterine fluid (over 79.2 litres in the left uterus, nutrient eggs and broken egg cases. The embryos had yolk stomachs that had ruptured, the mean volume of which was approximately 197.9 ml. Embryos had about 20 rows of potentially functional teeth in the upper and lower jaws. Periodic acid Schiff (PAS-positive substances were observed on the surface and in the cytoplasm of the epithelial cells, and large, secretory, OsO4-oxidized lipid droplets of various sizes were distributed on the surface of the villous string epithelium on the uterine wall. Histological examination of the uterine wall showed it to consist of villi, similar to the trophonemata of Dasyatidae rays, suggesting that the large amount of fluid found in the uterus of the white shark was likely required for embryo nutrition. We conclude that: (1 the lipid-rich fluid is secreted from the uterine epithelium only in early gestation before the onset of oophagy, (2 the embryos probably use the abundant uterine fluid and encased nutrient eggs for nutrition at this stage of their development, and (3 the uterine fluid is the major source of embryonic nutrition before oophagy onset. This is the first record of the lipid histotrophy of reproduction among all shark species.

  13. iDNA at Sea: Recovery of Whale Shark (Rhincodon typus Mitochondrial DNA Sequences from the Whale Shark Copepod (Pandarus rhincodonicus Confirms Global Population Structure

    Directory of Open Access Journals (Sweden)

    Mark Meekan

    2017-12-01

    Full Text Available The whale shark (Rhincodon typus is an iconic and endangered species with a broad distribution spanning warm-temperate and tropical oceans. Effective conservation management of the species requires an understanding of the degree of genetic connectivity among populations, which is hampered by the need for sampling that involves invasive techniques. Here, the feasibility of minimally-invasive sampling was explored by isolating and sequencing whale shark DNA from a commensal or possibly parasitic copepod, Pandarus rhincodonicus that occurs on the skin of the host. We successfully recovered mitochondrial control region DNA sequences (~1,000 bp of the host via DNA extraction and polymerase chain reaction from whole copepod specimens. DNA sequences obtained from multiple copepods collected from the same shark exhibited 100% sequence similarity, suggesting a persistent association of copepods with individual hosts. Newly-generated mitochondrial haplotypes of whale shark hosts derived from the copepods were included in an analysis of the genetic structure of the global population of whale sharks (644 sequences; 136 haplotypes. Our results supported those of previous studies and suggested limited genetic structuring across most of the species range, but the presence of a genetically unique and potentially isolated population in the Atlantic Ocean. Furthermore, we recovered the mitogenome and nuclear ribosomal genes of a whale shark using a shotgun sequencing approach on copepod tissue. The recovered mitogenome is the third mitogenome reported for the species and the first from the Mozambique population. Our invertebrate DNA (iDNA approach could be used to better understand the population structure of whale sharks, particularly in the Atlantic Ocean, and also for genetic analyses of other elasmobranchs parasitized by pandarid copepods.

  14. Spatio-temporal evolution of efficient subglacial water discharge at Lemon Creek Glacier, Alaska

    Science.gov (United States)

    Bartholomaus, T. C.; Labedz, C. R.; Amundson, J. M.; Gimbert, F.; Tsai, V. C.; Vore, M. E.; Karplus, M. S.

    2017-12-01

    The impact of subglacial hydrology on glacier motion, glacier erosion and sediment transport, and submarine melt is well established. However, despite its importance, critical gaps in our understanding of subglacial hydrology and its seasonal evolution remain, in large part due to the challenge of making observations of glacier beds. Thus far, no spatially extensive, temporally continuous observations of subglacial water discharge exist. Seismic signals produced by subglacial water flow, and which correlate with subglacial water discharge, can meet this need. Here, we present the first observations from a 2017 summer seismic, geodetic, and hydrologic experiment. Our experiment seeks to better understand the evolution of efficient subglacial drainage and water storage through data collection and analysis at Lemon Creek Glacier, a 5.7 km-long glacier with a gauged outlet in Southeast Alaska. Data with nested spatial resolutions create an unparalleled perspective of subglacial discharge and its seasonal evolution. Six broadband seismometers and two GPS receivers installed for 80 days provide a long-term view of subglacial discharge and its impact on glacier dynamics. More than 100 nodes, installed approximately every 250 m over the glacier surface ( 13 nodes per 1 km^2) and deployed for up to 25 days, reveal the detailed spatial pattern of glaciohydraulic tremor amplitudes. These nodes enable us to more precisely infer the locations of subglacial discharge and its change, as well as better interpret long-term patterns of glaciohydraulic tremor observed by the broadband seismometers. We infer the subglacial response to hydraulic transients over the duration of the deployment through examination of intermittent melt and rain events, and the abrupt drainage of a glacier-dammed lake. These observations demonstrate the promise of seismology to significantly advance our understanding of glacier hydrology and associated glaciological processes.

  15. Productive performance of hair lambs, fed with fresh lemon pulp as an energy source

    Directory of Open Access Journals (Sweden)

    Benigna Faustino-Lázaro

    2016-09-01

    Full Text Available Objective. Evaluate the effect of the inclusion of different levels of fresh lemon pulp (FLP was determined as a substitute of sorghum grain in the feeding of hair sheep in parameters of daily weight gain (DWG, daily food consumption (DFC, and feed conversion (FC, the nutritional composition of the ration was also determined. Materials and methods. The study was carried out using 20 hair ewes individually fed on a period of 75 days. The treatments were as follows: T1=0% FLP; T2=10% FLP; T3=20% FLP; and T4=30% FLP based on DM. A totally randomized design was used with five replicates per treatment. Concentrate and FLP were offered ad libitum as a mixture, registering the amounts of feed offered and rejected daily. Body weight was registered every 21 days for the DWG and analysis of nutritional composition of rations was performed. And for an analysis of daily food consumption. The data were evaluated through ANOVA in an entirely randomized design. Results. There was no meaningful difference (p>0.05 for the DWG that scored 97, 108, 103 and 103 g or for the FC that scored 9.62, 8.68, 9.31 and 10.23, respectively. For each treatment and for each DFC based on DM, a meaningful difference was observed (p<0.05 for T4 by replacing sorghum to 30%. Conclusions. FLP is an alternative to replace partially or completely the grains for hair ewes without lessening the evaluated parameters.

  16. IgM-mediated opsonization and cytotoxicity in the shark.

    Science.gov (United States)

    McKinney, E C; Flajnik, M F

    1997-02-01

    Two types of cytotoxic reactions have been observed using cells from the nurse shark: spontaneous cytotoxicity mediated by cells of the macrophage lineage and antibody-dependent killing carried out by a different effector cell population. Previous data showed that removal of phagocytic cells using iron particles abolished macrophage-mediated killing, but not antibody-dependent reactions. The current study used single cell assays and showed that the effector of antibody-driven reactions was the neutrophil. Surprisingly, the mechanism of killing was shown to be phagocytosis mediated by both 7S and 19S immunoglobulin M (IgM). Reactions proceeded with as little as 0.01 microg of purified 19S or 7S IgM and were complete within 4-6 h. In contrast, purified immunoglobulin did not adsorb to macrophages and had no effect on target cell binding or cytotoxicity. Pretreatment of cells with cytochalasin D abolished the phagocytic reaction, but not spontaneous cytotoxicity. These data show that antibody-mediated killing results from opsonization and phagocytosis; the mechanism of macrophage killing is currently unknown. In addition, these data show that the shark neutrophil, not the macrophage lineage, carries a receptor for Fc mu.

  17. Individual personality differences in Port Jackson sharks Heterodontus portusjacksoni.

    Science.gov (United States)

    Byrnes, E E; Brown, C

    2016-08-01

    This study examined interindividual personality differences between Port Jackson sharks Heterodontus portusjacksoni utilizing a standard boldness assay. Additionally, the correlation between differences in individual boldness and stress reactivity was examined, exploring indications of individual coping styles. Heterodontus portusjacksoni demonstrated highly repeatable individual differences in boldness and stress reactivity. Individual boldness scores were highly repeatable across four trials such that individuals that were the fastest to emerge in the first trial were also the fastest to emerge in subsequent trials. Additionally, individuals that were the most reactive to a handling stressor in the first trial were also the most reactive in a second trial. The strong link between boldness and stress response commonly found in teleosts was also evident in this study, providing evidence of proactive-reactive coping styles in H. portusjacksoni. These results demonstrate the presence of individual personality differences in sharks for the first time. Understanding how personality influences variation in elasmobranch behaviour such as prey choice, habitat use and activity levels is critical to better managing these top predators which play important ecological roles in marine ecosystems. © 2016 The Fisheries Society of the British Isles.

  18. Shark skin-inspired designs that improve aerodynamic performance.

    Science.gov (United States)

    Domel, August G; Saadat, Mehdi; Weaver, James C; Haj-Hariri, Hossein; Bertoldi, Katia; Lauder, George V

    2018-02-01

    There have been significant efforts recently aimed at improving the aerodynamic performance of aerofoils through the modification of their surfaces. Inspired by the drag-reducing properties of the tooth-like denticles that cover the skin of sharks, we describe here experimental and simulation-based investigations into the aerodynamic effects of novel denticle-inspired designs placed along the suction side of an aerofoil. Through parametric modelling to query a wide range of different designs, we discovered a set of denticle-inspired surface structures that achieve simultaneous drag reduction and lift generation on an aerofoil, resulting in lift-to-drag ratio improvements comparable to the best-reported for traditional low-profile vortex generators and even outperforming these existing designs at low angles of attack with improvements of up to 323%. Such behaviour is enabled by two concurrent mechanisms: (i) a separation bubble in the denticle's wake altering the flow pressure distribution of the aerofoil to enhance suction and (ii) streamwise vortices that replenish momentum loss in the boundary layer due to skin friction. Our findings not only open new avenues for improved aerodynamic design, but also provide new perspective on the role of the complex and potentially multifunctional morphology of shark denticles for increased swimming efficiency. © 2018 The Author(s).

  19. Smart Microgrid Energy Management Using a Novel Artificial Shark Optimization

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    Pawan Singh

    2017-01-01

    Full Text Available At present, renewable energy sources (RESs integration using microgrid (MG technology is of great importance for demand side management. Optimization of MG provides enhanced generation from RES at minimum operation cost. The microgrid optimization problem involves a large number of variables and constraints; therefore, it is complex in nature and various existing algorithms are unable to handle them efficiently. This paper proposed an artificial shark optimization (ASO method to remove the limitation of existing algorithms for solving the economical operation problem of MG. The ASO algorithm is motivated by the sound sensing capability of sharks, which they use for hunting. Further, the intermittent nature of renewable energy sources is managed by utilizing battery energy storage (BES. BES has several benefits. However, all these benefits are limited to a certain fixed area due to the stationary nature of the BES system. The latest technologies, such as electric vehicle technologies (EVTs, provide all benefits of BES along with mobility to support the variable system demands. Therefore, in this work, EVTs incorporated grid connected smart microgrid (SMG system is introduced. Additionally, a comparative study is provided, which shows that the ASO performs relatively better than the existing techniques.

  20. Molecular Phylogeny of the Bamboo Sharks (Chiloscyllium spp.

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    Noor Haslina Masstor

    2014-01-01

    Full Text Available Chiloscyllium, commonly called bamboo shark, can be found inhabiting the waters of the Indo-West Pacific around East Asian countries such as Malaysia, Myanmar, Thailand, Singapore, and Indonesia. The International Union for Conservation of Nature (IUCN Red List has categorized them as nearly threatened sharks out of their declining population status due to overexploitation. A molecular study was carried out to portray the systematic relationships within Chiloscyllium species using 12S rRNA and cytochrome b gene sequences. Maximum parsimony and Bayesian were used to reconstruct their phylogeny trees. A total of 381 bp sequences’ lengths were successfully aligned in the 12S rRNA region, with 41 bp sites being parsimony-informative. In the cytochrome b region, a total of 1120 bp sites were aligned, with 352 parsimony-informative characters. All analyses yield phylogeny trees on which C. indicum has close relationships with C. plagiosum. C. punctatum is sister taxon to both C. indicum and C. plagiosum while C. griseum and C. hasseltii formed their own clade as sister taxa. These Chiloscyllium classifications can be supported by some morphological characters (lateral dermal ridges on the body, coloring patterns, and appearance of hypobranchials and basibranchial plate that can clearly be used to differentiate each species.