keyword
MENU ▼
Read by QxMD icon Read
search

Sharks

keyword
https://www.readbyqxmd.com/read/29345743/refining-mortality-estimates-in-shark-demographic-analyses-a-bayesian-inverse-matrix-approach
#1
Jonathan J Smart, André E Punt, William T White, Colin A Simpfendorfer
Leslie matrix models are an important analysis tool in conservation biology that are applied to a diversity of taxa. The standard approach estimates the finite rate of population growth (λ) from a set of vital rates. In some instances, an estimate of λ is available, but the vital rates are poorly understood and can be solved for using an inverse matrix approach. However, these approaches are rarely attempted due to pre-requisites of information on the structure of age or stage-classes. This study addressed this issue by using a combination of Monte Carlo simulations and the sample-importance-resampling (SIR) algorithm to solve the inverse matrix problem without data on population structure...
January 18, 2018: Ecological Applications: a Publication of the Ecological Society of America
https://www.readbyqxmd.com/read/29343730/first-estimates-of-greenland-shark-somniosus-microcephalus-local-abundances-in-arctic-waters
#2
Brynn M Devine, Laura J Wheeland, Jonathan A D Fisher
Baited remote underwater video cameras were deployed in the Eastern Canadian Arctic, for the purpose of estimating local densities of the long-lived Greenland shark within five deep-water, data-poor regions of interest for fisheries development and marine conservation in Nunavut, Canada. A total of 31 camera deployments occurred between July-September in 2015 and 2016 during joint exploratory fishing and scientific cruises. Greenland sharks appeared at 80% of deployments. A total of 142 individuals were identified and no individuals were observed in more than one deployment...
January 17, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29341126/size-assessment-of-the-gray-reef-shark-carcharhinus-amblyrhynchos-inferred-from-teeth-marks-on-human-wounds
#3
Noémie Jublier, Eric E Clua
An accurate assessment of the biting shark size is paramount for better understanding the agonistic behavior of a species toward humans. The gray reef shark is involved in many accidental bites. Based on the capture of 35 gray sharks, we calculated the algorithm that allows the assessment of the shark size, through the interdental distance (IDD) inferred from teeth marks on human wounds. Our results show a negative allometric relationship and that IDD calculated from imprints perpetrated by the upper jaw are globally similar with those from the lower jaw, in spite of heterodonty...
January 16, 2018: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/29333348/a-new-species-of-cretalamna-sensu-stricto-lamniformes-otodontidae-from-the-late-cretaceous-santonian-campanian-of-alabama-usa
#4
Jun A Ebersole, Dana J Ehret
Decades of collecting from exposures of the Upper Cretaceous Tombigbee Sand Member of the Eutaw Formation and Mooreville Chalk in Alabama, USA has produced large numbers of isolated Cretalamna (sensu stricto) teeth. Many of these teeth had formerly been assigned to the extinct Late Cretaceous shark Cretalamna appendiculata (Agassiz, 1843), a taxon that is now considered largely restricted to the Turonian of Europe. Recent studies have shed light on the diversity of Late Cretaceous Cretalamna (s.s.) taxa, and here we recognize a new species from Alabama, Cretalamna bryanti...
2018: PeerJ
https://www.readbyqxmd.com/read/29324879/localized-zinc-distribution-in-shark-vertebrae-suggests-differential-deposition-during-ontogeny-and-across-vertebral-structures
#5
Vincent Raoult, Nicholas Howell, David Zahra, Victor M Peddemors, Daryl L Howard, Martin D de Jonge, Benjamin L Buchan, Jane E Williamson
The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders...
2018: PloS One
https://www.readbyqxmd.com/read/29323131/optimal-swimming-strategies%C3%A2-and-behavioral-plasticity-of-oceanic-whitetip-sharks
#6
Yannis P Papastamatiou, Gil Iosilevskii, Vianey Leos-Barajas, Edd J Brooks, Lucy A Howey, Demian D Chapman, Yuuki Y Watanabe
Animal behavior should optimize the difference between the energy they gain from prey and the energy they spend searching for prey. This is all the more critical for predators occupying the pelagic environment, as prey is sparse and patchily distributed. We theoretically derive two canonical swimming strategies for pelagic predators, that maximize their energy surplus while foraging. They predict that while searching, a pelagic predator should maintain small dive angles, swim at speeds near those that minimize the cost of transport, and maintain constant speed throughout the dive...
January 11, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29321624/strong-trans-pacific-break-and-local-conservation-units-in-the-galapagos-shark-carcharhinus-galapagensis-revealed-by-genome-wide-cytonuclear-markers
#7
Diana A Pazmiño, Gregory E Maes, Madeline E Green, Colin A Simpfendorfer, E Mauricio Hoyos-Padilla, Clinton J A Duffy, Carl G Meyer, Sven E Kerwath, Pelayo Salinas-de-León, Lynne van Herwerden
The application of genome-wide cytonuclear molecular data to identify management and adaptive units at various spatio-temporal levels is particularly important for overharvested large predatory organisms, often characterized by smaller, localized populations. Despite being "near threatened", current understanding of habitat use and population structure of Carcharhinus galapagensis is limited to specific areas within its distribution. We evaluated population structure and connectivity across the Pacific Ocean using genome-wide single-nucleotide polymorphisms (~7200 SNPs) and mitochondrial control region sequences (945 bp) for 229 individuals...
January 11, 2018: Heredity
https://www.readbyqxmd.com/read/29316367/development-of-the-lunate-shaped-caudal-fin-in-white-shark-embryos
#8
Taketeru Tomita, Minoru Toda, Kei Miyamoto, Shin-Ichiro Oka, Keiichi Ueda, Keiichi Sato
The lunate-shaped caudal fin in lamnid sharks is a morphological specialization for their thunniform mode of locomotion, but its developmental process during gestation has been poorly investigated. Observations of 21 embryonic specimens of the white shark (Carcharodon carcharias) revealed that their caudal fin morphology drastically changes from strongly heterocercal to lunate-shaped through ontogeny. This morphological change involves 1) rapid elongation of the ventral lobe, 2) increased upward curvature of the vertebra within the caudal fin, and 3) formation of keels at both lateral sides of the caudal fin base...
January 6, 2018: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/29316114/on-the-prevalence-and-dynamics-of-inverted-trophic-pyramids-and-otherwise-top-heavy-communities
#9
REVIEW
Douglas J McCauley, Gabriel Gellner, Neo D Martinez, Richard J Williams, Stuart A Sandin, Fiorenza Micheli, Peter J Mumby, Kevin S McCann
Classically, biomass partitioning across trophic levels was thought to add up to a pyramidal distribution. Numerous exceptions have, however, been noted including complete pyramidal inversions. Elevated levels of biomass top-heaviness (i.e. high consumer/resource biomass ratios) have been reported from Arctic tundra communities to Brazilian phytotelmata, and in species assemblages as diverse as those dominated by sharks and ants. We highlight two major pathways for creating top-heaviness, via: (1) endogenous channels that enhance energy transfer across trophic boundaries within a community and (2) exogenous pathways that transfer energy into communities from across spatial and temporal boundaries...
January 9, 2018: Ecology Letters
https://www.readbyqxmd.com/read/29315031/osmolyte-adjustments-as-a-pressure-adaptation-in-deep-sea-chondrichthyan-fishes-an-intraspecific-test-in-arctic-skates-amblyraja-hyperborea-along-a-depth-gradient
#10
Paul H Yancey, Ben Speers-Roesch, Sheila Atchinson, James D Reist, Andrew R Majewski, Jason R Treberg
Accumulation of trimethylamine N-oxide (TMAO) by deep-sea animals is proposed to protect proteins against the destabilizing effects of high hydrostatic pressure (the piezolyte hypothesis). Chondrichthyan fishes (sharks, rays, and chimaeras) provide a unique test of this hypothesis because shallow-living species have elevated TMAO levels to counteract the destabilizing effects of high urea levels accumulated for osmoregulation. Limited interspecific studies of chondrichthyans reveal that increasing depth correlates with decreased urea and increased TMAO levels, suggesting a dynamic balance between destabilizing forces on proteins (high urea, hydrostatic pressure) and TMAO to counteract these forces...
March 2018: Physiological and Biochemical Zoology: PBZ
https://www.readbyqxmd.com/read/29314672/-shark-island-pedicle-flap-zur-defektdeckung-der-lateralen-ala-nasi-und-perialarregion
#11
Andreas Volz, Vera Frauenknecht, Peter Häusermann
No abstract text is available yet for this article.
January 2018: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
https://www.readbyqxmd.com/read/29312815/satellite-tagging-highlights-the-importance-of-productive-mozambican-coastal-waters-to-the-ecology-and-conservation-of-whale-sharks
#12
Christoph A Rohner, Anthony J Richardson, Fabrice R A Jaine, Michael B Bennett, Scarla J Weeks, Geremy Cliff, David P Robinson, Katie E Reeve-Arnold, Simon J Pierce
The whale shark Rhincodon typus is an endangered, highly migratory species with a wide, albeit patchy, distribution through tropical oceans. Ten aerial survey flights along the southern Mozambican coast, conducted between 2004-2008, documented a relatively high density of whale sharks along a 200 km stretch of the Inhambane Province, with a pronounced hotspot adjacent to Praia do Tofo. To examine the residency and movement of whale sharks in coastal areas around Praia do Tofo, where they may be more susceptible to gill net entanglement, we tagged 15 juveniles with SPOT5 satellite tags and tracked them for 2-88 days (mean = 27 days) as they dispersed from this area...
2018: PeerJ
https://www.readbyqxmd.com/read/29307115/bioinformatic-analyses-of-zona-pellucida-genes-in-vertebrates-and-their-expression-in-nile-tilapia
#13
Tianli Wu, Yunying Cheng, Zhilong Liu, Wenjing Tao, Shuqing Zheng, Deshou Wang
Zona pellucida (ZP) genes encode ZP glycoproteins which constitute the coat surrounding oocytes and early embryos. Genome-wide identification of ZP genes is still lacking in vertebrates, especially in fish species. Herein, we conducted bioinformatic analyses of the ZP genes of the Nile tilapia and other vertebrates. Totally 16, 9, 17, 27, 21, 20, 26, 19, 14,11, 24, 17, 9, 18, 8, 11, 9, 8, 5, and 4 ZP genes belonging to 5 subfamilies (ZPA, ZPB, ZPC, ZPD, and ZPAX) were found in the sea lamprey, elephant shark, coelacanth, spotted gar, zebrafish, medaka, stickleback, Nile tilapia, Amazon molly, platyfish, seahorse, Northern snakehead, cavefish, tetraodon, clawed frog, turtle, chicken, platypus, kangaroo rat, and human genomes, respectively...
January 6, 2018: Fish Physiology and Biochemistry
https://www.readbyqxmd.com/read/29298937/an-early-chondrichthyan-and-the-evolutionary-assembly-of-a-shark-body-plan
#14
Michael I Coates, John A Finarelli, Ivan J Sansom, Plamen S Andreev, Katharine E Criswell, Kristen Tietjen, Mark L Rivers, Patrick J La Riviere
Although relationships among the major groups of living gnathostomes are well established, the relatedness of early jawed vertebrates to modern clades is intensely debated. Here, we provide a new description of Gladbachus, a Middle Devonian (Givetian approx. 385-million-year-old) stem chondrichthyan from Germany, and one of the very few early chondrichthyans in which substantial portions of the endoskeleton are preserved. Tomographic and histological techniques reveal new details of the gill skeleton, hyoid arch and jaws, neurocranium, cartilage, scales and teeth...
January 10, 2018: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/29237826/flaccid-skin-protects-hagfishes-from-shark-bites
#15
Sarah Boggett, Jean-Luc Stiles, Adam P Summers, Douglas S Fudge
Hagfishes defend themselves from fish predators by releasing large volumes of gill-clogging slime when they are attacked. Slime release is not anticipatory, but is only released after an attack has been initiated, raising the question of how hagfishes survive the initial attack, especially from biting predators such as sharks. We tested two hypotheses that could explain how hagfishes avoid damage from shark bites: puncture-resistant skin, and a loose and flaccid body design that makes it difficult for teeth to penetrate body musculature and viscera...
December 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/29233140/selection-characterization-and-thermal-stabilization-of-llama-single-domain-antibodies-towards-ebola-virus-glycoprotein
#16
Jinny L Liu, Lisa C Shriver-Lake, George P Anderson, Dan Zabetakis, Ellen R Goldman
BACKGROUND: A key advantage of recombinant antibody technology is the ability to optimize and tailor reagents. Single domain antibodies (sdAbs), the recombinantly produced variable domains derived from camelid and shark heavy chain antibodies, provide advantages of stability and solubility and can be further engineered to enhance their properties. In this study, we generated sdAbs specific for Ebola virus envelope glycoprotein (GP) and increased their stability to expand their utility for use in austere locals...
December 12, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/29232670/some-galeomorph-sharks-express-a-mammalian-microglia-specific-protein-in-radial-ependymoglia-of-the-telencephalon
#17
Skirmantas Janušonis
Ionized calcium-binding adapter molecule 1 (Iba1), also known as allograft inflammatory factor 1 (AIF-1), is a highly conserved cytoplasmic scaffold protein. Studies strongly suggest that Iba1 is associated with immune-like reactions in all Metazoa. In the mammalian brain, it is abundantly expressed in microglial cells and is used as a reliable marker for this cell type. The present study used multiple-label microscopy and Western blotting to examine Iba1 expression in the telencephalon of 2 galeomorph shark species, the swellshark (Cephaloscyllium ventriosum) and the horn shark (Heterodontus francisci), a member of an ancient extant order...
December 13, 2017: Brain, Behavior and Evolution
https://www.readbyqxmd.com/read/29232049/shark-island-pedicle-flap-for-reconstruction-of-the-lateral-nasal-ala-and-perialar-defects
#18
Andreas Volz, Vera Frauenknecht, Peter Häusermann
No abstract text is available yet for this article.
December 12, 2017: Journal der Deutschen Dermatologischen Gesellschaft, Journal of the German Society of Dermatology: JDDG
https://www.readbyqxmd.com/read/29230359/genetic-differentiation-and-phylogeography-of-mediterranean-north-eastern-atlantic-blue-shark-prionace-glauca-l-1758-using-mitochondrial-dna-panmixia-or-complex-stock-structure
#19
Agostino Leone, Ilenia Urso, Dimitrios Damalas, Jann Martinsohn, Antonella Zanzi, Stefano Mariani, Emilio Sperone, Primo Micarelli, Fulvio Garibaldi, Persefoni Megalofonou, Luca Bargelloni, Rafaella Franch, David Macias, Paulo Prodöhl, Séan Fitzpatrick, Marco Stagioni, Fausto Tinti, Alessia Cariani
Background: The blue shark (Prionace glauca, Linnaeus 1758) is one of the most abundant epipelagic shark inhabiting all the oceans except the poles, including the Mediterranean Sea, but its genetic structure has not been confirmed at basin and interoceanic distances. Past tagging programs in the Atlantic Ocean failed to find evidence of migration of blue sharks between the Mediterranean and the adjacent Atlantic, despite the extreme vagility of the species. Although the high rate of by-catch in the Mediterranean basin, to date no genetic study on Mediterranean blue shark was carried out, which constitutes a significant knowledge gap, considering that this population is classified as "Critically Endangered", unlike its open-ocean counterpart...
2017: PeerJ
https://www.readbyqxmd.com/read/29230354/ecomorphological-inferences-in-early-vertebrates-reconstructing-dunkleosteus-terrelli-arthrodira-placodermi-caudal-fin-from-palaeoecological-data
#20
Humberto G Ferrón, Carlos Martínez-Pérez, Héctor Botella
Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in non-closely related groups with similar lifestyles...
2017: PeerJ
keyword
keyword
47346
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"