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https://www.readbyqxmd.com/read/29148044/the-incidence-of-bent-dorsal-fins-in-free-ranging-cetaceans
#1
F Alves, J R Towers, R W Baird, G Bearzi, S Bonizzoni, R Ferreira, Z Halicka, A Alessandrini, A H Kopelman, C Yzoard, M H Rasmussen, C G Bertulli, E Jourdain, A Gullan, D Rocha, K Hupman, M-T Mrusczok, F I P Samarra, S Magalhães, C R Weir, J K B Ford, A Dinis
Laterally bent dorsal fins are rarely observed in free-ranging populations of cetaceans, contrary to captivity, where most killer whale Orcinus orca adult males have laterally collapsed fins. This topic has been poorly explored, and data/information on its occurrence and possible causes are limited. The present study: (i) undertakes a review of the available information on bent dorsal fins in free-ranging cetaceans, and updates it with new records, (ii) reports on the proportion of bent fins in different study populations, and (iii) discusses possible causes...
November 17, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/29145610/transition-to-an-aquatic-habitat-permitted-the-repeated-loss-of-the-pleiotropic-klk8-gene-in-mammals
#2
Nikolai Hecker, Virag Sharma, Michael Hiller
KLK8 (also called neuropsin) is a serine protease that plays distinct roles in the skin and hippocampus. In the skin, KLK8 influences keratinocyte proliferation and desquamation, and activates antimicrobial peptides in sweat. In the hippocampus, KLK8 affects memory acquisition. Here, we examined the evolution of KLK8 in mammals and discovered that, out of 70 placental mammals, KLK8 is exclusively lost in three independent fully-aquatic lineages, comprising dolphin, killer whale, minke whale and manatee. In addition, while the sperm whale has an intact KLK8 reading frame, the gene evolves neutrally in this species...
November 14, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/29127421/captive-bottlenose-dolphins-and-killer-whales-harbor-a-species-specific-skin-microbiota-that-varies-among-individuals
#3
M Chiarello, S Villéger, C Bouvier, J C Auguet, T Bouvier
Marine animals surfaces host diverse microbial communities, which play major roles for host's health. Most inventories of marine animal surface microbiota have focused on corals and fishes, while cetaceans remain overlooked. The few studies focused on wild cetaceans, making difficult to distinguish intrinsic inter- and/or intraspecific variability in skin microbiota from environmental effects. We used high-throughput sequencing to assess the skin microbiota from 4 body zones of 8 bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca), housed in captivity (Marineland park, France)...
November 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29096314/predicting-the-effects-of-polychlorinated-biphenyls-on-cetacean-populations-through-impacts-on-immunity-and-calf-survival
#4
Ailsa J Hall, Bernie J McConnell, Lori H Schwacke, Gina M Ylitalo, Rob Williams, Teri K Rowles
The potential impact of exposure to polychlorinated biphenyls (PCBs) on the health and survival of cetaceans continues to be an issue for conservation and management, yet few quantitative approaches for estimating population level effects have been developed. An individual based model (IBM) for assessing effects on both calf survival and immunity was developed and tested. Three case study species (bottlenose dolphin, humpback whale and killer whale) in four populations were taken as examples and the impact of varying levels of PCB uptake on achievable population growth was assessed...
October 30, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/29078030/four-odontocete-species-change-hearing-levels-when-warned-of-impending-loud-sound
#5
Paul E Nachtigall, Alexander Ya Supin, Aude F Pacini, Ronald A Kastelein
Hearing sensitivity change was investigated when a warning sound preceded a loud sound in the alse killer whale (Pseudorca crassidens) bottlenose dolphin (Tursiops truncatus) beluga whale (Delphinaperus leucas) and harbor porpoise (Phocoena phocoena). Hearing sensitivity was easured using pip-train test stimuli and auditory evoked potential recording. When the est/warning stimuli preceded a loud sound, hearing thresholds before the loud sound increased elative to the baseline by 13 to17 dB. Experiments with multiple frequencies of exposure and hift provided evidence of different amounts of hearing change depending on frequency, ndicating that the hearing sensation level changes were not likely due to a simple stapedial eflex...
October 27, 2017: Integrative Zoology
https://www.readbyqxmd.com/read/29074942/evaluating-anthropogenic-threats-to-endangered-killer-whales-to-inform-effective-recovery-plans
#6
Robert C Lacy, Rob Williams, Erin Ashe, Kenneth C Balcomb Iii, Lauren J N Brent, Christopher W Clark, Darren P Croft, Deborah A Giles, Misty MacDuffee, Paul C Paquet
Understanding cumulative effects of multiple threats is key to guiding effective management to conserve endangered species. The critically endangered, Southern Resident killer whale population of the northeastern Pacific Ocean provides a data-rich case to explore anthropogenic threats on population viability. Primary threats include: limitation of preferred prey, Chinook salmon; anthropogenic noise and disturbance, which reduce foraging efficiency; and high levels of stored contaminants, including PCBs. We constructed a population viability analysis to explore possible demographic trajectories and the relative importance of anthropogenic stressors...
October 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29070720/mortality-risk-and-social-network-position-in-resident-killer-whales-sex-differences-and-the-importance-of-resource-abundance
#7
S Ellis, D W Franks, S Nattrass, M A Cant, M N Weiss, D Giles, K C Balcomb, D P Croft
An individual's ecological environment affects their mortality risk, which in turn has fundamental consequences for life-history evolution. In many species, social relationships are likely to be an important component of an individual's environment, and therefore their mortality risk. Here, we examine the relationship between social position and mortality risk in resident killer whales (Orcinus orca) using over three decades of social and demographic data. We find that the social position of male, but not female, killer whales in their social unit predicts their mortality risk...
October 25, 2017: Proceedings. Biological Sciences
https://www.readbyqxmd.com/read/29021158/hierarchical-temporal-structure-in-music-speech-and-animal-vocalizations-jazz-is-like-a-conversation-humpbacks-sing-like-hermit-thrushes
#8
Christopher T Kello, Simone Dalla Bella, Butovens Médé, Ramesh Balasubramaniam
Humans talk, sing and play music. Some species of birds and whales sing long and complex songs. All these behaviours and sounds exhibit hierarchical structure-syllables and notes are positioned within words and musical phrases, words and motives in sentences and musical phrases, and so on. We developed a new method to measure and compare hierarchical temporal structures in speech, song and music. The method identifies temporal events as peaks in the sound amplitude envelope, and quantifies event clustering across a range of timescales using Allan factor (AF) variance...
October 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28876915/effects-of-polar-bear-and-killer-whale-derived-contaminant-cocktails-on-marine-mammal-immunity
#9
Jean-Pierre Desforges, Milton Levin, Lindsay Jasperse, Sylvain De Guise, Igor Eulaers, Robert J Letcher, Mario Acquarone, Erling Nordøy, Lars P Folkow, Trine Hammer Jensen, Carsten Grøndahl, Mads F Bertelsen, Judy St Leger, Javier Almunia, Christian Sonne, Rune Dietz
Most controlled toxicity studies use single chemical exposures that do not represent the real world situation of complex mixtures of known and unknown natural and anthropogenic substances. In the present study, complex contaminant cocktails derived from the blubber of polar bears (PB; Ursus maritimus) and killer whales (KW; Orcinus orca) were used for in vitro concentration-response experiments with PB, cetacean and seal spp. immune cells to evaluate the effect of realistic contaminant mixtures on various immune functions...
September 25, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28767655/beluga-whale-summer-habitat-associations-in-the-nelson-river-estuary-western-hudson-bay-canada
#10
Alexander J Smith, Jeff W Higdon, Pierre Richard, Jack Orr, Warren Bernhardt, Steven H Ferguson
To understand beluga whale (Delphinapterus leucas) estuarine use in the Nelson River estuary, southwest Hudson Bay, we recorded and examined beluga movements and habitat associations for the July through August period in 2002-2005. We compared locations of belugas fitted with satellite transmitters ("tags") (2002-2005) and aerial-surveyed (2003 and 2005) belugas for years of differing freshwater flow from the Nelson River which is influenced by hydroelectric activity. Using the beluga telemetry location data, we estimated an early August behavioral shift in beluga distribution patterns from local estuarine use to a progressively more migratory behavior away from the estuary...
2017: PloS One
https://www.readbyqxmd.com/read/28739936/gene-culture-coevolution-in-whales-and-dolphins
#11
Hal Whitehead
Whales and dolphins (Cetacea) have excellent social learning skills as well as a long and strong mother-calf bond. These features produce stable cultures, and, in some species, sympatric groups with different cultures. There is evidence and speculation that this cultural transmission of behavior has affected gene distributions. Culture seems to have driven killer whales into distinct ecotypes, which may be incipient species or subspecies. There are ecotype-specific signals of selection in functional genes that correspond to cultural foraging behavior and habitat use by the different ecotypes...
July 24, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28695252/oil-spills-and-marine-mammals-in-british-columbia-canada-development-and-application-of-a-risk-based-conceptual-framework
#12
Adrianne L Jarvela Rosenberger, Misty MacDuffee, Andrew G J Rosenberger, Peter S Ross
Marine mammals are inherently vulnerable to oil spills. We developed a conceptual framework to evaluate the impacts of potential oil exposure on marine mammals and applied it to 21 species inhabiting coastal British Columbia (BC), Canada. Oil spill vulnerability was determined by examining both the likelihood of species-specific (individual) oil exposure and the consequent likelihood of population-level effects. Oil exposure pathways, ecology, and physiological characteristics were first used to assign species-specific vulnerability rankings...
July 2017: Archives of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/28666015/first-longitudinal-study-of-seal-feeding-killer-whales-orcinus-orca-in-norwegian-coastal-waters
#13
Eve Jourdain, Dag Vongraven, Anna Bisther, Richard Karoliussen
Killer whales (Orcinus orca) have been documented preying on either fish or marine mammals in several regions, suggesting that this odontocete species has the ability to specialize on different types of prey. Off Norway, killer whales have been shown to rely on the Atlantic herring (Clupea harengus) as a main prey resource. Infrequent observations have revealed seals as an additional component of their diet, yet the extent of predation on marine mammals has remained largely unknown. Here, we present the findings of 29 years of photographic and observational data on seal-feeding killer whale groups identified in Norwegian coastal waters...
2017: PloS One
https://www.readbyqxmd.com/read/28662095/population-growth-is-limited-by-nutritional-impacts-on-pregnancy-success-in-endangered-southern-resident-killer-whales-orcinus-orca
#14
Samuel K Wasser, Jessica I Lundin, Katherine Ayres, Elizabeth Seely, Deborah Giles, Kenneth Balcomb, Jennifer Hempelmann, Kim Parsons, Rebecca Booth
The Southern Resident killer whale population (Orcinus orca) was listed as endangered in 2005 and shows little sign of recovery. These fish eating whales feed primarily on endangered Chinook salmon. Population growth is constrained by low offspring production for the number of reproductive females in the population. Lack of prey, increased toxins and vessel disturbance have been listed as potential causes of the whale's decline, but partitioning these pressures has been difficult. We validated and applied temporal measures of progesterone and testosterone metabolites to assess occurrence, stage and health of pregnancy from genotyped killer whale feces collected using detection dogs...
2017: PloS One
https://www.readbyqxmd.com/read/28649267/evidence-for-a-postreproductive-phase-in-female-false-killer-whales-pseudorca-crassidens
#15
Theoni Photopoulou, Ines M Ferreira, Peter B Best, Toshio Kasuya, Helene Marsh
BACKGROUND: A substantial period of life after reproduction ends, known as postreproductive lifespan (PRLS), is at odds with classical life history theory and its causes and mechanisms have puzzled evolutionary biologists for decades. Prolonged PRLS has been confirmed in only two non-human mammals, both odontocete cetaceans in the family Delphinidae. We investigate the evidence for PRLS in a third species, the false killer whale, Pseudorca crassidens, using a quantitative measure of PRLS and morphological evidence from reproductive tissues...
2017: Frontiers in Zoology
https://www.readbyqxmd.com/read/28636677/contextual-imitation-of-intransitive-body-actions-in-a-beluga-whale-delphinapterus-leucas-a-do-as-other-does-study
#16
José Z Abramson, Mª Victoria Hernández-Lloreda, José-Antonio Esteban, Fernando Colmenares, Francisco Aboitiz, Josep Call
Cetaceans are remarkable for exhibiting group-specific behavioral traditions or cultures in several behavioral domains (e.g., calls, behavioral tactics), and the question of whether they can be acquired socially, for example through imitative processes, remains open. Here we used a "Do as other does" paradigm to experimentally study the ability of a beluga to imitate familiar intransitive (body-oriented) actions demonstrated by a conspecific. The participant was first trained to copy three familiar behaviors on command (training phase) and then was tested for her ability to generalize the learned "Do as the other does" command to a different set of three familiar behaviors (testing phase)...
2017: PloS One
https://www.readbyqxmd.com/read/28554115/blubber-depth-distribution-and-bioaccumulation-of-pcbs-and-organochlorine-pesticides-in-arctic-invading-killer-whales
#17
Sara Pedro, Conor Boba, Rune Dietz, Christian Sonne, Aqqalu Rosing-Asvid, Martin Hansen, Anthony Provatas, Melissa A McKinney
Sightings of killer whales (Orcinus orca) in Greenland have increased in recent years, coincident with sea ice loss. These killer whales are likely from fish-feeding North Atlantic populations, but may have access to marine mammal prey in Greenlandic waters, which could lead to increased exposures to biomagnifying contaminants. Most studies on polychlorinated biphenyl (PCB) and organochlorine (OC) contaminants in killer whales have used biopsies which may not be representative of contaminant concentrations through the entire blubber depth...
December 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28528419/a-risk-based-characterization-of-sediment-contamination-by-legacy-and-emergent-contaminants-of-concern-in-coastal-british-columbia-canada
#18
Carmen Morales-Caselles, Jean-Pierre W Desforges, Neil Dangerfield, Peter S Ross
Sediments have long been used to help describe pollution sources, contaminated sites, trends over time, and habitat quality for marine life. We collected surficial sediments from 12 sites at an average seawater depth of 25 m in three near-urban areas of the Salish Sea (British Columbia, Canada) to investigate habitat quality for marine life, including heavily contaminated killer whales. Samples were analyzed using high-resolution instrumentation for a wide variety of congeners of polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), hexabromocyclododecane (HBCDD), polybrominated biphenyls, polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans, organochlorine pesticides, and polychlorinated naphthalenes (PCNs)...
August 2017: Archives of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/28464669/killer-whale-orcinus-orca-behavioral-audiograms
#19
Brian K Branstetter, Judy St Leger, Doug Acton, John Stewart, Dorian Houser, James J Finneran, Keith Jenkins
Killer whales (Orcinus orca) are one of the most cosmopolitan marine mammal species with potential widespread exposure to anthropogenic noise impacts. Previous audiometric data on this species were from two adult females [Szymanski, Bain, Kiehl, Pennington, Wong, and Henry (1999). J. Acoust. Soc. Am. 108, 1322-1326] and one sub-adult male [Hall and Johnson (1972). J. Acoust. Soc. Am. 51, 515-517] with apparent high-frequency hearing loss. All three killer whales had best sensitivity between 15 and 20 kHz, with thresholds lower than any odontocete tested to date, suggesting this species might be particularly sensitive to acoustic disturbance...
April 2017: Journal of the Acoustical Society of America
https://www.readbyqxmd.com/read/28341854/gliding-locomotion-of-manta-rays-killer-whales-and-swordfish-near-the-water-surface
#20
Jie-Min Zhan, Ye-Jun Gong, Tian-Zeng Li
The hydrodynamic performance of the locomotive near the water surface is impacted by its geometrical shape. For marine animals, their geometrical shape is naturally selective; thus, investigating gliding locomotion of marine animal under the water surface may be able to elucidate the influence of the geometrical shape. We investigate three marine animals with specific geometries: the killer whale is fusiform shaped; the manta ray is flat and broad-winged; and the swordfish is best streamlined. The numerical results are validated by the measured drag coefficients of the manta ray model in a towing tank...
March 24, 2017: Scientific Reports
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