The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
Colleen Reichmuth - One of the best experts on this subject based on the ideXlab platform.
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Molting strategies of Arctic seals drive annual patterns in metabolism.
Conservation physiology, 2021Co-Authors: Nicole M. Thometz, Holly Hermann-sorensen, Brandon Russell, David A. S. Rosen, Colleen ReichmuthAbstract:Arctic seals, including spotted (Phoca Largha), ringed (Pusa hispida) and bearded (Erignathus barbatus) seals, are directly affected by sea ice loss. These species use sea ice as a haul-out substrate for various critical functions, including their annual molt. Continued environmental warming will inevitably alter the routine behavior and overall energy budgets of Arctic seals, but it is difficult to quantify these impacts as their metabolic requirements are not well known-due in part to the difficulty of studying wild individuals. Thus, data pertaining to species-specific energy demands are urgently needed to better understand the physiological consequences of rapid environmental change. We used open-flow respirometry over a four-year period to track fine-scale, longitudinal changes in the resting metabolic rate (RMR) of four spotted seals, three ringed seals and one bearded seal trained to participate in research. Simultaneously, we collected complementary physiological and environmental data. Species-specific metabolic demands followed expected patterns based on body size, with the largest species, the bearded seal, exhibiting the highest absolute RMR (0.48 ± 0.04 L O2 min-1) and the lowest mass-specific RMR (4.10 ± 0.47 ml O2 min-1 kg-1), followed by spotted (absolute: 0.33 ± 0.07 L O2 min-1; mass-specific: 6.13 ± 0.73 ml O2 min-1 kg-1) and ringed (absolute: 0.20 ± 0.04 L O2 min-1; mass-specific: 7.01 ± 1.38 ml O2 min-1 kg-1) seals. Further, we observed clear and consistent annual patterns in RMR that related to the distinct molting strategies of each species. For species that molted over relatively short intervals-spotted (33 ± 4 days) and ringed (28 ± 6 days) seals-metabolic demands increased markedly in association with molt. In contrast, the bearded seal exhibited a prolonged molting strategy (119 ± 2 days), which appeared to limit the overall cost of molting as indicated by a relatively stable annual RMR. These findings highlight energetic trade-offs associated with different molting strategies and provide quantitative data that can be used to assess species-specific vulnerabilities to changing conditions.
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Table_1_Comparative Health Assessments of Alaskan Ice Seals.XLSX
2019Co-Authors: Caroline E. C. Goertz, Colleen Reichmuth, Nicole M. Thometz, Heather Ziel, Peter BovengAbstract:Bearded (Erignathus barbatus), ringed (Pusa hispida), spotted (Phoca Largha), and ribbon (HistrioPhoca fasciata) seals rely on seasonal sea-ice in Arctic and sub-Arctic regions. Many aspects of the biology and physiology of these seals are poorly known, and species-typical health parameters are not available for all species. Such information has proven difficult to obtain due to the challenges of studying Arctic seals in the wild and their minimal historic representation in aquaria. Here, we combine diagnostic information gathered between 2000 and 2017 from free-ranging seals, seals in short-term rehabilitation, and seals living in long-term human care to evaluate and compare key health parameters. For individuals in apparent good health, hematology, and blood chemistry values are reported by the source group for 10 bearded, 13 ringed, 73 spotted, and 81 ribbon seals from Alaskan waters. For a smaller set of individuals handled during veterinary or necropsy procedures, the presence of parasites and pathogens is described, as well as exposure to a variety of infectious diseases known to affect marine mammals and/or humans, with positive titers observed for Brucella, Leptospira, avian influenza, herpesvirus PhHV-1, and morbillivirus. These data provide initial baseline parameters for hematology, serum chemistries, and other species-level indicators of health that can be used to assess the condition of individual seals, inform monitoring and management efforts, and guide directed research efforts for Alaskan populations of ice-associated seals.
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Comparative Health Assessments of Alaskan Ice Seals
Frontiers Media S.A., 2019Co-Authors: Caroline E. C. Goertz, Colleen Reichmuth, Nicole M. Thometz, Heather Ziel, Peter BovengAbstract:Bearded (Erignathus barbatus), ringed (Pusa hispida), spotted (Phoca Largha), and ribbon (HistrioPhoca fasciata) seals rely on seasonal sea-ice in Arctic and sub-Arctic regions. Many aspects of the biology and physiology of these seals are poorly known, and species-typical health parameters are not available for all species. Such information has proven difficult to obtain due to the challenges of studying Arctic seals in the wild and their minimal historic representation in aquaria. Here, we combine diagnostic information gathered between 2000 and 2017 from free-ranging seals, seals in short-term rehabilitation, and seals living in long-term human care to evaluate and compare key health parameters. For individuals in apparent good health, hematology, and blood chemistry values are reported by the source group for 10 bearded, 13 ringed, 73 spotted, and 81 ribbon seals from Alaskan waters. For a smaller set of individuals handled during veterinary or necropsy procedures, the presence of parasites and pathogens is described, as well as exposure to a variety of infectious diseases known to affect marine mammals and/or humans, with positive titers observed for Brucella, Leptospira, avian influenza, herpesvirus PhHV-1, and morbillivirus. These data provide initial baseline parameters for hematology, serum chemistries, and other species-level indicators of health that can be used to assess the condition of individual seals, inform monitoring and management efforts, and guide directed research efforts for Alaskan populations of ice-associated seals
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psychoacoustic studies of spotted Phoca Largha and ringed pusa hispida seals
Advances in Experimental Medicine and Biology, 2016Co-Authors: Jillian M Sills, Brandon L Southall, Colleen ReichmuthAbstract:Human development of the marine environment raises questions regarding the potential adverse effects of anthropogenic noise on marine mammals. For species that live in remote Arctic regions, recent and expanding human intrusions may pose a particular threat. Northern seals are poorly studied relative to their temperate counterparts and little is known of their acoustic ecology or behavior. Given this scarcity of relevant data, studies of hearing in Arctic seals are essential to characterize their auditory capabilities and to inform management decisions. This paper describes ongoing psychoacoustic studies that are examining aspects of hearing in two ice seal species.
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amphibious hearing in spotted seals Phoca Largha underwater audiograms aerial audiograms and critical ratio measurements
The Journal of Experimental Biology, 2014Co-Authors: Jillian M Sills, Brandon L Southall, Colleen ReichmuthAbstract:Spotted seals (Phoca Largha) inhabit Arctic regions that are facing both rapid climate change and increasing industrialization. While little is known about their sensory capabilities, available knowledge suggests that spotted seals and other ice seals use sound to obtain information from the surrounding environment. To quantitatively assess their auditory capabilities, the hearing of two young spotted seals was tested using a psychophysical paradigm. Absolute detection thresholds for tonal sounds were measured in air and under water over the frequency range of hearing, and critical ratios were determined using octave-band masking noise in both media. The behavioral audiograms show a range of best sensitivity spanning four octaves in air, from approximately 0.6 to 11 kHz. The range of sensitive hearing extends across seven octaves in water, with lowest thresholds between 0.3 and 56 kHz. Critical ratio measurements were similar in air and water and increased monotonically from 12 dB at 0.1 kHz to 30 dB at 25.6 kHz, indicating that the auditory systems of these seals are quite efficient at extracting signals from background noise. This study demonstrates that spotted seals possess sound reception capabilities different from those previously described for ice seals, and more similar to those reported for harbor seals (Phoca vitulina). The results are consistent with the amphibious lifestyle of these seals and their apparent reliance on sound. The hearing data reported herein are the first available for spotted seals and can inform best management practices for this vulnerable species in a changing Arctic.
Joon Yoon - One of the best experts on this subject based on the ideXlab platform.
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deciphering the evolutionary signatures of pinnipeds using novel genome sequences the first genomes of Phoca Largha callorhinus ursinus and eumetopias jubatus
Scientific Reports, 2018Co-Authors: Jung Youn Park, Hawsun Sohn, Jungha Kang, Yongrock An, Jaehoon Jung, Samsun Sung, Woori Kwak, Joon YoonAbstract:The pinnipeds, which comprise seals, sea lions, and walruses, are a remarkable group of marine animals with unique adaptations to semi-aquatic life. However, their genomes are poorly characterized. In this study, we sequenced and characterized the genomes of three pinnipeds (Phoca Largha, Callorhinus ursinus, and Eumetopias jubatus), focusing on site-wise sequence changes. We detected rapidly evolving genes in pinniped lineages and substitutions unique to pinnipeds associated with amphibious sound perception. Phenotypic convergence-related sequence convergences are not common in marine mammals. For example, FASN, KCNA5, and IL17RA contain substitutions specific to pinnipeds, yet are potential candidates of phenotypic convergence (blubber, response to hypoxia, and immunity to pathogens) in all marine mammals. The outcomes of this study will provide insight into targets for future studies of convergent evolution or gene function.
Jillian M Sills - One of the best experts on this subject based on the ideXlab platform.
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psychoacoustic studies of spotted Phoca Largha and ringed pusa hispida seals
Advances in Experimental Medicine and Biology, 2016Co-Authors: Jillian M Sills, Brandon L Southall, Colleen ReichmuthAbstract:Human development of the marine environment raises questions regarding the potential adverse effects of anthropogenic noise on marine mammals. For species that live in remote Arctic regions, recent and expanding human intrusions may pose a particular threat. Northern seals are poorly studied relative to their temperate counterparts and little is known of their acoustic ecology or behavior. Given this scarcity of relevant data, studies of hearing in Arctic seals are essential to characterize their auditory capabilities and to inform management decisions. This paper describes ongoing psychoacoustic studies that are examining aspects of hearing in two ice seal species.
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amphibious hearing in spotted seals Phoca Largha underwater audiograms aerial audiograms and critical ratio measurements
The Journal of Experimental Biology, 2014Co-Authors: Jillian M Sills, Brandon L Southall, Colleen ReichmuthAbstract:Spotted seals (Phoca Largha) inhabit Arctic regions that are facing both rapid climate change and increasing industrialization. While little is known about their sensory capabilities, available knowledge suggests that spotted seals and other ice seals use sound to obtain information from the surrounding environment. To quantitatively assess their auditory capabilities, the hearing of two young spotted seals was tested using a psychophysical paradigm. Absolute detection thresholds for tonal sounds were measured in air and under water over the frequency range of hearing, and critical ratios were determined using octave-band masking noise in both media. The behavioral audiograms show a range of best sensitivity spanning four octaves in air, from approximately 0.6 to 11 kHz. The range of sensitive hearing extends across seven octaves in water, with lowest thresholds between 0.3 and 56 kHz. Critical ratio measurements were similar in air and water and increased monotonically from 12 dB at 0.1 kHz to 30 dB at 25.6 kHz, indicating that the auditory systems of these seals are quite efficient at extracting signals from background noise. This study demonstrates that spotted seals possess sound reception capabilities different from those previously described for ice seals, and more similar to those reported for harbor seals (Phoca vitulina). The results are consistent with the amphibious lifestyle of these seals and their apparent reliance on sound. The hearing data reported herein are the first available for spotted seals and can inform best management practices for this vulnerable species in a changing Arctic.
Jung Youn Park - One of the best experts on this subject based on the ideXlab platform.
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deciphering the evolutionary signatures of pinnipeds using novel genome sequences the first genomes of Phoca Largha callorhinus ursinus and eumetopias jubatus
Scientific Reports, 2018Co-Authors: Jung Youn Park, Hawsun Sohn, Jungha Kang, Yongrock An, Jaehoon Jung, Samsun Sung, Woori Kwak, Joon YoonAbstract:The pinnipeds, which comprise seals, sea lions, and walruses, are a remarkable group of marine animals with unique adaptations to semi-aquatic life. However, their genomes are poorly characterized. In this study, we sequenced and characterized the genomes of three pinnipeds (Phoca Largha, Callorhinus ursinus, and Eumetopias jubatus), focusing on site-wise sequence changes. We detected rapidly evolving genes in pinniped lineages and substitutions unique to pinnipeds associated with amphibious sound perception. Phenotypic convergence-related sequence convergences are not common in marine mammals. For example, FASN, KCNA5, and IL17RA contain substitutions specific to pinnipeds, yet are potential candidates of phenotypic convergence (blubber, response to hypoxia, and immunity to pathogens) in all marine mammals. The outcomes of this study will provide insight into targets for future studies of convergent evolution or gene function.
Jacques Godfroid - One of the best experts on this subject based on the ideXlab platform.
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Brucella Antibodies in Alaskan True Seals and Eared Seals—Two Different Stories
Frontiers in veterinary science, 2018Co-Authors: Ingebjørg Helena Nymo, Rolf Rødven, Kimberlee B. Beckmen, Anett Kristin Larsen, Morten Tryland, Lori T. Quakenbush, Jacques GodfroidAbstract:Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA) and the Rose Bengal test (RBT) were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus) (2%) and none of the 107 Northern fur seals (Callorhinus ursinus). The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina) (25%), spotted seals (Phoca Largha) (19%), ribbon seals (HistrioPhoca fasciata) (16%), and ringed seals (Pusa hispida hispida) (14%). There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a following clearance of infection. Furthermore, analyses by region showed minor differences in the probability of being seropositive for harbor seals from different regions regardless of the local seal population trend, signifying that the Brucella infection may not cause significant mortality in these populations. In conclusion, the Brucella infection pattern is very different for eared and true seals.
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brucella antibodies in alaskan true seals and eared seals two different stories
Frontiers in Veterinary Science, 2018Co-Authors: Ingebjørg Helena Nymo, Rolf Rødven, Kimberlee B. Beckmen, Anett Kristin Larsen, Morten Tryland, Lori T. Quakenbush, Jacques GodfroidAbstract:Brucella pinnipedialis was first isolated from true seals in 1994 and from eared seals in 2008. Although few pathological findings have been associated with infection in true seals, reproductive pathology including abortions, and the isolation of the zoonotic strain type 27 have been documented in eared seals. In this study, a Brucella enzyme-linked immunosorbent assay (ELISA) and the Rose Bengal test (RBT) were initially compared for 206 serum samples and a discrepancy between the tests was found. Following removal of lipids from the serum samples, ELISA results were unaltered while the agreement between the tests was improved, indicating that serum lipids affected the initial RBT outcome. For the remaining screening, we used ELISA to investigate the presence of Brucella antibodies in sera of 231 eared and 1,412 true seals from Alaskan waters sampled between 1975 and 2011. In eared seals, Brucella antibodies were found in two Steller sea lions (Eumetopias jubatus) (2%) and none of the 107 Northern fur seals (Callorhinus ursinus). The low seroprevalence in eared seals indicate a low level of exposure or lack of susceptibility to infection. Alternatively, mortality due to the Brucella infection may remove seropositive animals from the population. Brucella antibodies were detected in all true seal species investigated; harbor seals (Phoca vitulina) (25%), spotted seals (Phoca Largha) (19%), ribbon seals (HistrioPhoca fasciata) (16%), and ringed seals (Pusa hispida hispida) (14%). There was a low seroprevalence among pups, a higher seroprevalence among juveniles, and a subsequent decreasing probability of seropositivity with age in harbor seals. Similar patterns were present for the other true seal species; however, solid conclusions could not be made due to sample size. This pattern is in accordance with previous reports on B. pinnipedialis infections in true seals and may suggest environmental exposure to B. pinnipedialis at the juvenile stage, with a following clearance of infection. Furthermore, analyses by region showed minor differences in the probability of being seropositive for harbor seals from different regions regardless of the local seal population trend, signifying that the Brucella infection may not cause significant mortality in these populations. In conclusion, the Brucella infection pattern is very different for eared and true seals.