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https://www.readbyqxmd.com/read/28093310/effects-of-glucose-and-insulin-administration-on-glucose-transporter-expression-in-the-north-pacific-spiny-dogfish-squalus-suckleyi
#1
Courtney A Deck, W Gary Anderson, Patrick J Walsh
Elasmobranchs (sharks, skates, and rays) are a primarily carnivorous group of fish, consuming few carbohydrates. Further, they tend to exhibit delayed responses to glucose and insulin administration in vivo relative to mammals, leading to a presumption of glucose-intolerance. To investigate the glucoregulatory capabilities of the spiny dogfish (Squalus suckleyi), plasma glucose concentration, muscle and liver glycogen content, and glucose transporter (glut1 and 4) mRNA levels were measured following intra-arterial administration of bovine insulin (10 ng kg(-1)) or an approximate doubling of fasting plasma glucose concentration...
January 13, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28091617/switch-from-sexual-to-parthenogenetic-reproduction-in-a-zebra-shark
#2
Christine L Dudgeon, Laura Coulton, Ren Bone, Jennifer R Ovenden, Severine Thomas
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...
January 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28089553/plastic-debris-straps-on-threatened-blue-shark-prionace-glauca
#3
Ana I Colmenero, Claudio Barría, Elisabetta Broglio, Salvador García-Barcelona
Juveniles of blue shark Prionace glauca caught in pelagic longlines targeting tuna and swordfish in the Atlantic Ocean and the Mediterranean Sea were found entangled with plastic straps around their gill region. The plastic debris were identified as strapping bands and caused several degrees of injuries on the dorsal musculature and pectoral fins. They were also obstructing the gill slits probably causing breathing issues. These records were uploaded in the web site seawatchers.org, and highlight the potential of citizen science in revealing the occurrence of such problems which could help to measure the effects of plastic debris on marine life...
January 12, 2017: Marine Pollution Bulletin
https://www.readbyqxmd.com/read/28080920/phaeohyphomycosis-associated-with-ossification-of-the-skull-and-cervical-vertebrae-in-a-swell-shark-cephaloscyllium-ventriosum
#4
Claire D Erlacher-Reid, Hendrik H Nollens, Todd L Schmitt, Judy St Leger, Sarena Sunico
A female, captive bred, juvenile swell shark ( Cephaloscyllium ventriosum ) was observed swimming in tight circles and rolling. Radiographs and computed tomography of this individual revealed extensive cartilage mineralization of the skull and cranial cervical vertebrae compared with diagnostic images of clinically healthy conspecifics. Gross necropsy and histopathologic examination revealed ossification and fibrosis of the cartilaginous matrix of the skull and cervical vertebrae with deep invasion by a pigmented hyphal fungus...
December 2016: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
https://www.readbyqxmd.com/read/28080905/plasma-protein-electrophoresis-and-select-acute-phase-proteins-in-healthy-bonnethead-sharks-sphyrna-tiburo-under-managed-care
#5
Michael W Hyatt, Cara L Field, Tonya M Clauss, Kristopher L Arheart, Carolyn Cray
Preventative health care of elasmobranchs is an important but understudied field of aquatic veterinary medicine. Evaluation of inflammation through the acute phase response is a valuable tool in health assessments. To better assess the health of bonnethead sharks ( Sphyrna tiburo ) under managed care, normal reference intervals of protein electrophoresis (EPH) and the acute phase proteins, C-reactive protein (CRP) and haptoglobin (HP), were established. Blood was collected from wild caught, captive raised bonnethead sharks housed at public aquaria...
December 2016: Journal of Zoo and Wildlife Medicine: Official Publication of the American Association of Zoo Veterinarians
https://www.readbyqxmd.com/read/28078785/risks-of-ocean-acidification-in-the-california-current-food-web-and-fisheries-ecosystem-model-projections
#6
Kristin N Marshall, Isaac C Kaplan, Emma E Hodgson, Albert Hermann, D Shallin Busch, Paul McElhany, Timothy E Essington, Chris J Harvey, Elizabeth A Fulton
The benefits and ecosystem services that humans derive from the oceans are threatened by numerous global change stressors, one of which is ocean acidification. Here, we describe the effects of ocean acidification on an upwelling system that already experiences inherently low pH conditions, the California Current. We used an end-to-end ecosystem model (Atlantis), forced by downscaled global climate models and informed by a meta-analysis of the pH sensitivities of local taxa, to investigate the direct and indirect effects of future pH on biomass and fisheries revenues...
January 12, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28071651/marine-origin-of-retroviruses-in-the-early-palaeozoic-era
#7
Pakorn Aiewsakun, Aris Katzourakis
Very little is known about the ancient origin of retroviruses, but owing to the discovery of their ancient endogenous viral counterparts, their early history is beginning to unfold. Here we report 36 lineages of basal amphibian and fish foamy-like endogenous retroviruses (FLERVs). Phylogenetic analyses reveal that ray-finned fish FLERVs exhibit an overall co-speciation pattern with their hosts, while amphibian FLERVs might not. We also observe several possible ancient viral cross-class transmissions, involving lobe-finned fish, shark and frog FLERVs...
January 10, 2017: Nature Communications
https://www.readbyqxmd.com/read/28070810/trace-element-concentrations-in-muscle-tissue-of-milk-shark-rhizoprionodon-acutus-from-the-persian-gulf
#8
Milad Adel, Kolsoom Mohammadmoradi, Cesar P Ley-Quiñonez
We analyze the heavy metals concentrations in muscle samples of milk shark (Rhizoprionodon acutus) from Persian Gulf. The metals distribution was Zn > Cu > Pb > Cd > Hg. No statistical differences were observed among size or weight by sex (p < 0.05). Metals concentrations in the population de R. acutus from Larak and Lavan islands are homogeneous along the coastal study area. Our study suggest that the results reflect the natural contents of trace metals in this species, and the health risk associated to milk shark consumption in Persian Gulf is relatively low...
January 9, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28062301/evolution-of-specificity-in-cartilaginous-fish-glycoprotein-hormones-and-receptors
#9
Hanna B Buechi, Jamie T Bridgham
Glycoprotein hormones (GpH) interact very specifically with their receptors to mediate hypothalamic - pituitary - peripheral gland endocrine signaling. Vertebrates typically have three functionally distinct GpH endocrine signaling complexes: follicle-stimulating hormone, luteinizing hormone, and thyroid-stimulating hormone, and their receptors. Each hormone consists of a common α subunit bound to one of three different β subunits. Individual hormone subunits and receptors are present in genomes of early metazoans, and a subset of hormone subunits and receptors has been recently characterized in sea lamprey...
January 3, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28059780/separation-control-over-a-grooved-surface-inspired-by-dolphin-skin
#10
Amy Lang, Emily Jones, Farhana Afroz
Over many decades the biological surfaces of aquatic swimmers have been studied for their potential as drag reducing surfaces. The hydrodynamic benefit of riblets, or grooves embedded parallel to the flow which appear on surfaces such as shark skin, have been well documented. However the skin of dolphins is embedded with sinusoidal grooves that run perpendicular or transverse to the flow over their bodies. It is theorized that the transverse grooves present on dolphin skin trap vortices between them, creating a partial slip condition over the surface and inducing turbulence augmentation in the boundary layer, thus acting as a potential mechanism to reduce flow separation and thus pressure drag...
January 6, 2017: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/28052054/a-symmoriiform-chondrichthyan-braincase-and-the-origin-of-chimaeroid-fishes
#11
Michael I Coates, Robert W Gess, John A Finarelli, Katharine E Criswell, Kristen Tietjen
Chimaeroid fishes (Holocephali) are one of the four principal divisions of modern gnathostomes (jawed vertebrates). Despite only 47 described living species, chimaeroids are the focus of resurgent interest as potential archives of genomic data and for the unique perspective they provide on chondrichthyan and gnathostome ancestral conditions. Chimaeroids are also noteworthy for their highly derived body plan. However, like other living groups with distinctive anatomies, fossils have been of limited use in unravelling their evolutionary origin, as the earliest recognized examples already exhibit many of the specializations present in modern forms...
January 4, 2017: Nature
https://www.readbyqxmd.com/read/28039876/selected-least-studied-but-not-forgotten-bioluminescent-systems
#12
Yuichi Oba, Cassius V Stevani, Anderson G Oliveira, Aleksandra S Tsarkova, Tatiana V Chepurnykh, Ilia V Yampolsky
Bioluminescence is a form of chemiluminescence generated by luminous organisms. Luminous taxa have currently been reported from about 800 genera and probably over 10,000 species in the world. On the other hand, their bioluminescent systems, including chemical structures of luciferins/chromophores and the genes encoding luciferases/photoproteins, have been elucidated from only a few taxonomic groups; e.g. beetles, bacteria, dinoflagellates, ostracods, and some cnidarians. Research efforts to understand unknown bioluminescence systems are being conducted around the world, and recently, for example, novel luciferin structures of luminous enchytraeid potworms and fungi were identified by the authors...
December 31, 2016: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28039527/individual-level-behavioral-responses-of-immature-green-turtles-to-snorkeler-disturbance
#13
Lucas P Griffin, Jacob W Brownscombe, Tyler O Gagné, Alexander D M Wilson, Steven J Cooke, Andy J Danylchuk
Despite many positive benefits of ecotourism, increased human encounters with wildlife may have detrimental effects on wild animals. As charismatic megafauna, nesting and foraging sea turtles are increasingly the focus of ecotourism activities. The purpose of our study was to quantify the behavioral responses of immature green turtles (Chelonia mydas) to disturbance by snorkelers, and to investigate whether turtles have individual-level responses to snorkeler disturbance. Using a standardized disturbance stimulus in the field, we recorded turtle behaviors pre- and post-disturbance by snorkelers...
December 30, 2016: Oecologia
https://www.readbyqxmd.com/read/28026866/comments-on-annotated-checklist-of-the-living-sharks-batoids-and-chimaeras-chondrichthyes-of-the-world-with-a-focus-on-biogeographical-diversity-weigmann
#14
https://www.readbyqxmd.com/read/28026018/a-preliminary-investigation-into-the-morphology-of-oral-papillae-and-denticles-of-blue-sharks-prionace-glauca-with-inferences-about-its-functional-significance-across-life-stages
#15
Bianca de S Rangel, Natascha Wosnick, Neil Hammerschlag, Adriano P Ciena, José Roberto Kfoury Junior, Rose E G Rici
Sensory organs in elasmobranchs (sharks, skates, rays) detect and respond to a different set of biotic and/or abiotic stimuli, through sight, smell, taste, hearing, mechanoreception and electroreception. Although gustation is crucial for survival and essential for growth, mobility, and maintenance of neural activity and the proper functioning of the immune system, comparatively little is known about this sensory system in elasmobranchs. Here we present a preliminary investigation into the structural and dimensional characteristics of the oral papillae and denticles found in the oropharyngeal cavity of the blue shark (Prionace glauca) during embryonic development through adulthood...
December 27, 2016: Journal of Anatomy
https://www.readbyqxmd.com/read/28018629/the-ecological-connectivity-of-whale-shark-aggregations-in-the-indian-ocean-a-photo-identification-approach
#16
Samantha Andrzejaczek, Jessica Meeuwig, David Rowat, Simon Pierce, Tim Davies, Rebecca Fisher, Mark Meekan
Genetic and modelling studies suggest that seasonal aggregations of whale sharks (Rhincodon typus) at coastal sites in the tropics may be linked by migration. Here, we used photo-identification (photo-ID) data collected by both citizen scientists and researchers to assess the connectedness of five whale shark aggregation sites across the entire Indian Ocean at timescales of up to a decade. We used the semi-automated program I(3)S (Individual Interactive Identification System) to compare photographs of the unique natural marking patterns of individual whale sharks collected from aggregations at Mozambique, the Seychelles, the Maldives, Christmas Island (Australia) and Ningaloo Reef (Australia)...
November 2016: Royal Society Open Science
https://www.readbyqxmd.com/read/28018617/cutting-blade-dentitions-in-squaliform-sharks-form-by-modification-of-inherited-alternate-tooth-ordering-patterns
#17
Charlie Underwood, Zerina Johanson, Moya Meredith Smith
The squaliform sharks represent one of the most speciose shark clades. Many adult squaliforms have blade-like teeth, either on both jaws or restricted to the lower jaw, forming a continuous, serrated blade along the jaw margin. These teeth are replaced as a single unit and successor teeth lack the alternate arrangement present in other elasmobranchs. Micro-CT scans of embryos of squaliforms and a related outgroup (Pristiophoridae) revealed that the squaliform dentition pattern represents a highly modified version of tooth replacement seen in other clades...
November 2016: Royal Society Open Science
https://www.readbyqxmd.com/read/28008936/enhanced-locomotion-efficiency-of-a-bio-inspired-walking-robot-using-contact-surfaces-with-frictional-anisotropy
#18
Poramate Manoonpong, Dennis Petersen, Alexander Kovalev, Florentin Wörgötter, Stanislav N Gorb, Marlene Spinner, Lars Heepe
Based on the principles of morphological computation, we propose a novel approach that exploits the interaction between a passive anisotropic scale-like material (e.g., shark skin) and a non-smooth substrate to enhance locomotion efficiency of a robot walking on inclines. Real robot experiments show that passive tribologically-enhanced surfaces of the robot belly or foot allow the robot to grip on specific surfaces and move effectively with reduced energy consumption. Supplementing the robot experiments, we investigated tribological properties of the shark skin as well as its mechanical stability...
December 23, 2016: Scientific Reports
https://www.readbyqxmd.com/read/28008824/triloculotrema-euzeti-n-sp-monogenea-monocotylidae-from-the-nasal-tissues-of-the-blackspotted-smooth-hound-mustelus-punctulatus-carcharhiniformes-triakidae-from-off-tunisia
#19
Lobna Boudaya, Lassad Neifar
Triloculotrema euzeti n. sp. (Monogenea, Monocotylidae, Merizocotylinae) is described from the nasal tissues of the blackspotted smooth-hound Mustelus punctulatus collected from the coastal marine waters off Tunisia. The new parasite species is distinguished from the other two species of the genus, T. japanicae Kearn, 1993 and T. chisholmae Justine, 2009, by the morphology of the sclerotised male copulatory organ which has longitudinal ridges. The species is also characterised by its oötype with short descending and ascending limbs (long and more convoluted in the other two species)...
2016: Parasite: Journal de la Société Française de Parasitologie
https://www.readbyqxmd.com/read/27995903/experimental-study-of-laminar-and-turbulent-boundary-layer-separation-control-of-shark-skin
#20
Farhana Afroz, Amy Lang, Maria Laura Habegger, Philip Motta, Robert Hueter
The Shortfin Mako shark (Isurus oxyrinchus) is a fast swimmer and has incredible turning agility, and has flexible scales known to bristle up to 50° in the flank regions. It is purported that this bristling capability of the scales may result in a unique pass flow control method to control flow separation and reduce drag. It appears that the scales have evolved to be only actuated when the flow over the body is reversed; thereby inducing a method of inhibiting flow reversal close to the surface. In addition, bristled scales form cavities which could induce boundary layer mixing and further assist in delaying flow separation...
December 20, 2016: Bioinspiration & Biomimetics
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