Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10 week ... more Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10 week period, commencing at 5 weeks prior to egg lay (EL), to increase our understanding of the species' reproductive biology. Females in cordoned nest sites underwent cloacal artificial insemination (AI) every 4-7 days with different semen donors for each insemination. The EL interval was 97.9 ± 3.6 h (range: 84-108 h) and paternity analyses revealed that conceptive inseminations occurred from 11.5 to 4.5 days before oviposition. A biphasic pattern of estradiol, testosterone, progesterone and the biochemical analytes triglyceride, iron, calcium and phosphorus occurred in relation to EL, with values increasing (P < 0.05) to maximal concentrations during the three weeks preceding oviposition, then decreasing (P < 0.05) rapidly after oviposition completion. In comparison with post-lay (baseline) values, concentrations of estradiol and testosterone relative to the first oviposition were elevated at Week-5, and those of triglyceride, a yolk formation index, as well as iron, calcium and phosphorus, became elevated at Week-4 (P < 0.05). Collective data indicate an estimated total egg formation interval of 29 days, with oviducal transit of the ovulated ovum occurring over the majority of the $4 day EL interval. These findings indicate that egg formation is prolonged with folliculogenesis initiated at 5 weeks or more prior to oviposition. Consequently, the period of folliculogenesis and egg formation is estimated to overlap with the final $3 weeks that wild females spend at sea prior to returning to land for breeding.
Erysipelothrix rhusiopathiae is the causative agent of erysipeloid in humans and of erysipelas in... more Erysipelothrix rhusiopathiae is the causative agent of erysipeloid in humans and of erysipelas in various animals, including bottlenose dolphins Tursiops truncatus, in which an infection has the potential to cause peracute septicemia and death. The purpose of this study was to evaluate the efficacy of using an off-label porcine (ER BAC PLUS ® , Zoetis) E. rhusiopathiae bactrin in a bottlenose dolphin vaccination program by determining the anti-E. rhusiopathiae antibody levels in vaccinated dolphins over a 10 yr period. Serum samples (n = 88) were analyzed using a modified fluorescent microbead immunoassay from 54 dolphins, including 3 individuals with no history of vaccination and 51 dolphins with an average of 5 vaccinations, 3 of which had previously recovered from a natural E. rhusiopathiae infection. A mean 311-fold increase in the immuno globulin G (IgG) antibody index was measured in a subsample of 10 dolphins 14 d after the first booster vaccination. Serum IgG antibody titers were influenced by number of vaccines received (r 2 = 0.47, p < 0.05) but not by age, gender, history of natural infection, adverse vaccine reaction, vaccination interval or time since last vaccination. The commercial pig bacterin was deemed effective in generating humoral immunity against E. rhusiopathiae in dolphins. However, since the probability of an adverse reaction toward the vaccine was moderately correlated (p = 0.07, r 2 = 0.1) with number of vaccines administered, more research is needed to determine the optimal vaccination interval.
Comparisons of circulating and excreted corticosteroid profiles during a biological stress respon... more Comparisons of circulating and excreted corticosteroid profiles during a biological stress response could provide more data concerning the timing and magnitude of acute hormone changes in different sample matrices. A stress test was performed in 13 zoo-based killer whales (Orcinus orca) whereby animals were elevated out of the water on a rising lift-bottom platform for 20 min. Paired blood and feces were tested for cortisol, corticosterone, aldosterone, and their metabolites and hematological and serum chemistry parameters. Circulating corticosteroids significantly increased during the stress test and returned to pre-treatment concentrations within 24 h, indicating hypothalamic-pituitary-adrenal-axis activation. Concentrations of fecal corticosteroid metabolites did not change significantly during the stress test. Significant differences between pre-test levels and the stress test stage were observed for counts of white blood cells and absolute neutrophils, consistent with a stress leukogram. For serum chemistry, significant deviations from baseline levels were seen for the majority (20/37) of measured parameters. This study provides a direct measurement of the physiologic response of clinically healthy killer whales to a stress event. However, due to the lack of significant changes in fecal hormone metabolite profiles, further investigation of the excretory dynamics of corticosteroids during acute and chronic stress is warranted.
A female, captive bred, juvenile swell shark (Cephaloscyllium ventriosum) was observed swimming i... more 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. There was no growth on fungal culture, but fungal polymerase chain reaction identified a DNA sequence compatible with Exophiala sp. (99%). Radiographs and computed tomography were helpful to determine a prognosis and course of action for this individual. This case emphasizes the need to include fungal infections as a differential diagnosis when evaluating elasmobranchs with abnormal swimming behaviors and mineralization of the skeletal structures.
Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointes... more Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointestinal (GI) function in humans and some animal species. Serum cobalamin and folate concentrations in an ex situ population of killer whales (Orcinus orca) were measured and factors that may affect their serum concentrations were identified. Serum samples (n ¼ 104) were analyzed from killer whales (n ¼ 10) both while clinically healthy and during periods of clinical GI disease as defined by clinical signs and fecal cytology. To characterize serum cobalamin and folate concentrations in clinically healthy animals, a mixed-model regression was used, with cobalamin and folate both significantly affected by weight (cobalamin: P , 0.0001, folate: P ¼ 0.006) and season (cobalamin: P , 0.0001, folate: P , 0.0001). The marginal mean concentrations for cobalamin and folate across weight and season were 742 6 53.6 ng/L and 30.2 6 2.6 lg/L, respectively. The predicted 95% confidence intervals (CI) for these analytes were then compared with samples collected during periods of GI disease. Across individuals, 22% (2/9) of the folate and 80% (8/10) of the cobalamin samples from the animals with GI disease fell outside the 95% CI for the population. When comparing samples within an individual, a similar pattern presented, with 100% of cobalamin of the observed abnormal samples reduced compared to healthy animal concentration variability. The same was not true for folate. These results suggest that serum concentrations of cobalamin and folate may be useful minimally invasive markers to identify GI disease in killer whales, especially when values are compared within an individual.
Proceedings of the National Academy of Sciences of the United States of America, Mar 22, 2021
Significance In diving birds like penguins, physiologic considerations suggest that increased hem... more Significance In diving birds like penguins, physiologic considerations suggest that increased hemoglobin (Hb)-O 2 affinity may improve pulmonary O 2 extraction and enhance dive capacity. We integrated experimental tests on whole-blood and native Hbs of penguins with protein engineering experiments on reconstructed ancestral Hbs. The experiments involving ancestral protein resurrection enabled us to test for evolved changes in Hb function in the stem lineage of penguins after divergence from their closest nondiving relatives. We demonstrate that penguins evolved an increased Hb-O 2 affinity in conjunction with a greatly augmented Bohr effect (i.e., reduction in Hb-O 2 affinity at low pH) that should maximize pulmonary O 2 extraction without compromising O 2 delivery at systemic capillaries.
Persistent organic pollutants (POPs) pose a health risk for southern resident killer whales (SRKW... more Persistent organic pollutants (POPs) pose a health risk for southern resident killer whales (SRKWs). Data on maternal contaminant transfer to calves are needed to inform models that estimate future contaminant loads as well as assess risk to newborn killer whale calves exposed to POPs. We conducted a study on trained female killer whales and their calves to fill these data gaps. POPs and lipid content were quantified in blood serum (POP levels in serum and blubber are highly correlated) collected during gestation and in milk and serum collected post-partum from female killer whales. Serum samples were also collected from calves during the lactation period. POP concentrations in milk collected over 15 months post-partum from the primiparous female decreased by 47-65%, depending on the contaminant class. The highest influx of contaminants to calves tended to occur soon after birth. Greater contaminant transfer rates during early lactation were also reflected in maternal serum POP levels. POP levels in maternal serum decreased significantly during the first 144-158 days post-partum, depending on contaminant class, and then leveled off through the remaining lactation period. This resulted in 67-81% reductions in POP levels in maternal serum over 15 months. By 15 months post-partum, serum POP levels from the primiparous female had dropped to levels measured in the multiparous female during pregnancy. Dissimilar to the multiparous female, body mass and blubber thickness in the primiparous female also declined significantly during the first 3-5 months post-partum, demonstrating linkages between lipid and POP transfer from blubber stores to milk in early lactation. By the end of lactation, lipid-corrected POP concentrations in serum from the first-born calf were 5-8 times greater than the corresponding POP levels from her primiparous mother. These results demonstrate that very young neonatal SRKW calves, particularly first-born calves, are at high risk from contaminant exposure
bioRxiv (Cold Spring Harbor Laboratory), Dec 4, 2021
Physio-logging methods, which use animal-borne devices to record physiological variables, are ent... more Physio-logging methods, which use animal-borne devices to record physiological variables, are entering a new era driven by advances in sensor development. However, existing datasets collected with traditional bio-loggers, such as accelerometers, still contain untapped eco-physiological information. Here we present a computational method for extracting heartrate from high-resolution accelerometer data using a ballistocardiogram. We validated our method with simultaneous accelerometer-electrocardiogram tag deployments in a controlled setting on a killer whale (Orcinus orca) and demonstrate the method recovers previously observed cardiovascular patterns in a blue whale (Balaenoptera musculus), including the magnitude of apneic bradycardia and increase in heart rate prior to and during ascent. Our ballistocardiogram method may be applied to mine heart rates from previously collected accelerometery and expand our understanding of comparative cardiovascular physiology.
OBJECTIVE To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and w... more OBJECTIVE To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and without cardiomyopathy and describe 2 cases of cardiomyopathy with different etiologies. ANIMALS 25 free-ranging southern sea otters (Enhydra lutris nereis) with (n = 14; cases) and without (11; controls) cardiomyopathy and 17 healthy managed southern sea otters from aquariums or rehabilitation centers (controls). PROCEDURES Serum cTnI concentration was measured in live sea otters. Histopathologic and gross necropsy findings were used to classify cardiomyopathy status in free-ranging otters; physical examination and echocardiography were used to assess health status of managed otters. Two otters received extensive medical evaluations under managed care, including diagnostic imaging, serial cTnI concentration measurement, and necropsy. RESULTS A significant difference in cTnI concentrations was observed between cases and both control groups, with median values of 0.279 ng/mL for cases and ...
Dietary cation-anion difference may explain why ammonium Dietary cation-anion difference may expl... more Dietary cation-anion difference may explain why ammonium Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more frequently in common urate nephrolithiasis occurs more frequently in common bottlenose dolphins (bottlenose dolphins (Tursiops truncatus Tursiops truncatus) under human care than) under human care than in free-ranging common bottlenose dolphins in free-ranging common bottlenose dolphins
SummaryEpigenetics has hitherto been studied and understood largely at the level of individual or... more SummaryEpigenetics has hitherto been studied and understood largely at the level of individual organisms. Here, we report a multi-faceted investigation of DNA methylation across 11,117 samples from 176 different species. We performed an unbiased clustering of individual cytosines into 55 modules and identified 31 modules related to primary traits including age, species lifespan, sex, adult species weight, tissue type and phylogenetic order. Analysis of the correlation between DNA methylation and species allowed us to construct phyloepigenetic trees for different tissues that parallel the phylogenetic tree. In addition, while some stable cytosines reflect phylogenetic signatures, others relate to age and lifespan, and in many cases responding to anti-aging interventions in mice such as caloric restriction and ablation of growth hormone receptors. Insights uncovered by this investigation have important implications for our understanding of the role of epigenetics in mammalian evolutio...
Background Pacific walruses are found in Arctic regions of the Chukchi and Bering Sea where rapid... more Background Pacific walruses are found in Arctic regions of the Chukchi and Bering Sea where rapid changes in environmental conditions resulting in loss of sea ice are occurring. Therefore, accurate life history data are crucial for species management plans and longitudinal data collected over the lives of individual walruses housed in zoos and aquaria provide otherwise difficult to obtain biological information. Results While similar at birth, Gompertz regression curves indicated that males grew faster than females (p < 0.0001) in weight (99 kg vs 57.6 kg/y) and length (26.9 cm vs 26.3 cm/y) with physical differences being detected by age 3 for weight and age 7 for length. Males reached adult weight at 13.5 ± 3.3 y and females by age 12.3 ± 2.3 y. The mean age at first ovulation and at first conception occurred at 8.8 y and 9.6 y. Greater than 75% of all conceptions and calving occurred between February and March and from May to June, respectively. Mean gestation lasted 423 d and...
This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plas... more This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plasma, whole blood (WB), and blubber from wild Alaskan (Bristol Bay) belugas (Delphinapterus leucas) (BBB, n = 9) with oceanaria-based belugas (OBB, n = 14) fed a controlled diet consisting of primarily herring (Clupea harengus) and capelin (Mallotus villosus). FA patterns in RBCs, WB, and plasma varied considerably between BBB and OBB animals. Focusing on RBC FA levels of known dietary origin, the OBBs had markedly higher levels of 20:1n9,11 and 22:1n9,11. RBC levels of these fatty acids were 1% and 0.2% in the BBBs, but 8.2% and 4.5%, respectively, in the OBBs (p < 0.05 both). These long-chain mono-unsaturated FAs (LC-MUFAs) are rich in herring and capelin but not in the prey species (i.e., salmonids, smelt, cod, and shrimp) generally available to BBBs. As for the marine omega-3 poly-unsaturated fatty acids [PUFAs; 20:5n3 (eicosapentaenoic acid) and 22:6n3 (docosahexaenoic acid)], the ...
Abstract: The pharmacokinetics of danofloxacin was investigated in rehabilitated California brown... more Abstract: The pharmacokinetics of danofloxacin was investigated in rehabilitated California brown pelicans (Pelecanus occidentalis californicus) after a single intramuscular injection at a dose of 15 mg/kg body weight. The concentration of the drug in plasma was assayed by high-pressure liquid chromatography. A sparse-sampling design was used to reduce the number of samples (1–4 venipunctures) obtained from 24 brown pelicans. A population pharmacokinetic analysis with nonlinear mixed-effects modeling was used to accommodate the sparse-sampling strategy. The nonlinear mixed-effects modeling approach measured both fixed effects (typical values for the population) and random effects (between-subject variability) for this population. A 1-compartment model best represented the concentration-versus-time data after injection. After injection, the elimination half-life, peak concentration, area under the curve, and volume of distribution were 2.76 hours, 2.5 µg/mL, 13.75 µg/h/mL, and 4.35 L/kg, respectively. Rate of absorption was highly variable among the birds. The intramuscular injection of danofloxacin in pelicans at this dose produced plasma concentrations that meet therapeutic targets for bacteria with a minimum inhibitory concentration of ≤0.25 µg/mL. This dose can be used for future studies to evaluate the efficacy of danofloxacin for treating susceptible bacteria.
A juvenile female California sea lion (Zalophus californianus) presented with a firm subcutaneous... more A juvenile female California sea lion (Zalophus californianus) presented with a firm subcutaneous mass in the right caudoventral pelvic region, measuring approximately 15 3 15 cm, and edema in the right hind flipper. The initial diagnostic workup included an ultrasound, blood analysis, and fine-needle aspirate of the mass under manual restraint. While the blood analysis was within normal limits, the ultrasound revealed a large discrete hyperechoic homogeneous mass with anastomosing hypoechoic fluid pockets that, when aspirated, was suggestive of a reactive lymph node. Short-term empiric antibiotic therapy prescribed to address possible lymphadenitis yielded no response, and edema of the right hind flipper and perianal region worsened. The sea lion was anesthetized to facilitate a more thorough exam, repeat blood analysis, obtain survey radiographs, evaluate with ultrasound, and perform biopsy of mass. The thoracic radiographs were normal; however, the large radiopaque mass was observed cranial to the pelvis on lateral abdominal view and appeared solitary on ultrasound. An exploratory surgery was performed to completely excise the mass. On histopathologic review, the mass demonstrated diffuse fibrous hyperplasia of lobular ducts of the mammary gland and mild mastitis, characterizing it as a mammary fibroadenoma. The surgical wound healed within 6 wk, and there was no recurrence of mammary hyperplasia.
For many reptile species, adequate ultraviolet B (UVB) radiation is essential for proper calcium ... more For many reptile species, adequate ultraviolet B (UVB) radiation is essential for proper calcium metabolism. In this study, the effects of UVB radiation on calcium metabolism were evaluated in green sea turtles (Chelonia mydas). 25-Hydroxyvitamin D, parathyroid hormone (PTH), and ionized calcium (iCa) were measured in juvenile (n = 18, 9 indoor, 9 outdoor) and adult (n = 8, 4 indoor, 4 outdoor) turtles. All animals were fed an identical diet. Outdoor animals had access to unfiltered sunlight, whereas indoor animals were housed under artificial lighting without UVB. Mean values for 25-hydroxyvitamin D for the outdoor and indoor groups were 34.33 ± 7.98 nmol/L and 7.11 ± 1.69 nmol/L for juveniles and 73.25 ± 30.34 nmol/L and 14.0 ± 11.52 nmol/L for adults respectively. Mean values for iCa for the outdoor and indoor groups were 0.98 ± 0.07 mmol/L and 0.99 ± 0.06 mmol/L for juveniles and 1.18 ± 0.22 mmol/L and 0.97 ± 0.18 mmol/L for adults respectively. UVB exposure (P < 0.001) and age (P < 0.001) had a significant effect on 25-hydroxyvitamin D as well as a significant interaction between the two variables (P = 0.008), with highest values in adult outdoor turtles. There was a significant interaction between age group and UVB status for iCa (P = 0.036), with greater values in older outdoor turtles. 25-Hydroxyvitamin D and total calcium were positively correlated, rs = 0.39, P = 0.042. iCa and calcium-to-phosphorus ratios were also positively correlated, rs = 0.42, P = 0.027. These results suggest that UVB exposure is an important source of 25-hydroxyvitamin D for green sea turtles and has significant effects on calcium metabolism in this species. PTH values in this study were near the minimum limits of detection and suggest that current mammalian-based PTH assays are not valid for reptiles.
Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10 week ... more Eight captive female Magellanic penguins (Spheniscus magellanicus) were monitored over a 10 week period, commencing at 5 weeks prior to egg lay (EL), to increase our understanding of the species' reproductive biology. Females in cordoned nest sites underwent cloacal artificial insemination (AI) every 4-7 days with different semen donors for each insemination. The EL interval was 97.9 ± 3.6 h (range: 84-108 h) and paternity analyses revealed that conceptive inseminations occurred from 11.5 to 4.5 days before oviposition. A biphasic pattern of estradiol, testosterone, progesterone and the biochemical analytes triglyceride, iron, calcium and phosphorus occurred in relation to EL, with values increasing (P < 0.05) to maximal concentrations during the three weeks preceding oviposition, then decreasing (P < 0.05) rapidly after oviposition completion. In comparison with post-lay (baseline) values, concentrations of estradiol and testosterone relative to the first oviposition were elevated at Week-5, and those of triglyceride, a yolk formation index, as well as iron, calcium and phosphorus, became elevated at Week-4 (P < 0.05). Collective data indicate an estimated total egg formation interval of 29 days, with oviducal transit of the ovulated ovum occurring over the majority of the $4 day EL interval. These findings indicate that egg formation is prolonged with folliculogenesis initiated at 5 weeks or more prior to oviposition. Consequently, the period of folliculogenesis and egg formation is estimated to overlap with the final $3 weeks that wild females spend at sea prior to returning to land for breeding.
Erysipelothrix rhusiopathiae is the causative agent of erysipeloid in humans and of erysipelas in... more Erysipelothrix rhusiopathiae is the causative agent of erysipeloid in humans and of erysipelas in various animals, including bottlenose dolphins Tursiops truncatus, in which an infection has the potential to cause peracute septicemia and death. The purpose of this study was to evaluate the efficacy of using an off-label porcine (ER BAC PLUS ® , Zoetis) E. rhusiopathiae bactrin in a bottlenose dolphin vaccination program by determining the anti-E. rhusiopathiae antibody levels in vaccinated dolphins over a 10 yr period. Serum samples (n = 88) were analyzed using a modified fluorescent microbead immunoassay from 54 dolphins, including 3 individuals with no history of vaccination and 51 dolphins with an average of 5 vaccinations, 3 of which had previously recovered from a natural E. rhusiopathiae infection. A mean 311-fold increase in the immuno globulin G (IgG) antibody index was measured in a subsample of 10 dolphins 14 d after the first booster vaccination. Serum IgG antibody titers were influenced by number of vaccines received (r 2 = 0.47, p < 0.05) but not by age, gender, history of natural infection, adverse vaccine reaction, vaccination interval or time since last vaccination. The commercial pig bacterin was deemed effective in generating humoral immunity against E. rhusiopathiae in dolphins. However, since the probability of an adverse reaction toward the vaccine was moderately correlated (p = 0.07, r 2 = 0.1) with number of vaccines administered, more research is needed to determine the optimal vaccination interval.
Comparisons of circulating and excreted corticosteroid profiles during a biological stress respon... more Comparisons of circulating and excreted corticosteroid profiles during a biological stress response could provide more data concerning the timing and magnitude of acute hormone changes in different sample matrices. A stress test was performed in 13 zoo-based killer whales (Orcinus orca) whereby animals were elevated out of the water on a rising lift-bottom platform for 20 min. Paired blood and feces were tested for cortisol, corticosterone, aldosterone, and their metabolites and hematological and serum chemistry parameters. Circulating corticosteroids significantly increased during the stress test and returned to pre-treatment concentrations within 24 h, indicating hypothalamic-pituitary-adrenal-axis activation. Concentrations of fecal corticosteroid metabolites did not change significantly during the stress test. Significant differences between pre-test levels and the stress test stage were observed for counts of white blood cells and absolute neutrophils, consistent with a stress leukogram. For serum chemistry, significant deviations from baseline levels were seen for the majority (20/37) of measured parameters. This study provides a direct measurement of the physiologic response of clinically healthy killer whales to a stress event. However, due to the lack of significant changes in fecal hormone metabolite profiles, further investigation of the excretory dynamics of corticosteroids during acute and chronic stress is warranted.
A female, captive bred, juvenile swell shark (Cephaloscyllium ventriosum) was observed swimming i... more 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. There was no growth on fungal culture, but fungal polymerase chain reaction identified a DNA sequence compatible with Exophiala sp. (99%). Radiographs and computed tomography were helpful to determine a prognosis and course of action for this individual. This case emphasizes the need to include fungal infections as a differential diagnosis when evaluating elasmobranchs with abnormal swimming behaviors and mineralization of the skeletal structures.
Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointes... more Cobalamin and folate are water-soluble vitamins that are useful indicators of chronic gastrointestinal (GI) function in humans and some animal species. Serum cobalamin and folate concentrations in an ex situ population of killer whales (Orcinus orca) were measured and factors that may affect their serum concentrations were identified. Serum samples (n ¼ 104) were analyzed from killer whales (n ¼ 10) both while clinically healthy and during periods of clinical GI disease as defined by clinical signs and fecal cytology. To characterize serum cobalamin and folate concentrations in clinically healthy animals, a mixed-model regression was used, with cobalamin and folate both significantly affected by weight (cobalamin: P , 0.0001, folate: P ¼ 0.006) and season (cobalamin: P , 0.0001, folate: P , 0.0001). The marginal mean concentrations for cobalamin and folate across weight and season were 742 6 53.6 ng/L and 30.2 6 2.6 lg/L, respectively. The predicted 95% confidence intervals (CI) for these analytes were then compared with samples collected during periods of GI disease. Across individuals, 22% (2/9) of the folate and 80% (8/10) of the cobalamin samples from the animals with GI disease fell outside the 95% CI for the population. When comparing samples within an individual, a similar pattern presented, with 100% of cobalamin of the observed abnormal samples reduced compared to healthy animal concentration variability. The same was not true for folate. These results suggest that serum concentrations of cobalamin and folate may be useful minimally invasive markers to identify GI disease in killer whales, especially when values are compared within an individual.
Proceedings of the National Academy of Sciences of the United States of America, Mar 22, 2021
Significance In diving birds like penguins, physiologic considerations suggest that increased hem... more Significance In diving birds like penguins, physiologic considerations suggest that increased hemoglobin (Hb)-O 2 affinity may improve pulmonary O 2 extraction and enhance dive capacity. We integrated experimental tests on whole-blood and native Hbs of penguins with protein engineering experiments on reconstructed ancestral Hbs. The experiments involving ancestral protein resurrection enabled us to test for evolved changes in Hb function in the stem lineage of penguins after divergence from their closest nondiving relatives. We demonstrate that penguins evolved an increased Hb-O 2 affinity in conjunction with a greatly augmented Bohr effect (i.e., reduction in Hb-O 2 affinity at low pH) that should maximize pulmonary O 2 extraction without compromising O 2 delivery at systemic capillaries.
Persistent organic pollutants (POPs) pose a health risk for southern resident killer whales (SRKW... more Persistent organic pollutants (POPs) pose a health risk for southern resident killer whales (SRKWs). Data on maternal contaminant transfer to calves are needed to inform models that estimate future contaminant loads as well as assess risk to newborn killer whale calves exposed to POPs. We conducted a study on trained female killer whales and their calves to fill these data gaps. POPs and lipid content were quantified in blood serum (POP levels in serum and blubber are highly correlated) collected during gestation and in milk and serum collected post-partum from female killer whales. Serum samples were also collected from calves during the lactation period. POP concentrations in milk collected over 15 months post-partum from the primiparous female decreased by 47-65%, depending on the contaminant class. The highest influx of contaminants to calves tended to occur soon after birth. Greater contaminant transfer rates during early lactation were also reflected in maternal serum POP levels. POP levels in maternal serum decreased significantly during the first 144-158 days post-partum, depending on contaminant class, and then leveled off through the remaining lactation period. This resulted in 67-81% reductions in POP levels in maternal serum over 15 months. By 15 months post-partum, serum POP levels from the primiparous female had dropped to levels measured in the multiparous female during pregnancy. Dissimilar to the multiparous female, body mass and blubber thickness in the primiparous female also declined significantly during the first 3-5 months post-partum, demonstrating linkages between lipid and POP transfer from blubber stores to milk in early lactation. By the end of lactation, lipid-corrected POP concentrations in serum from the first-born calf were 5-8 times greater than the corresponding POP levels from her primiparous mother. These results demonstrate that very young neonatal SRKW calves, particularly first-born calves, are at high risk from contaminant exposure
bioRxiv (Cold Spring Harbor Laboratory), Dec 4, 2021
Physio-logging methods, which use animal-borne devices to record physiological variables, are ent... more Physio-logging methods, which use animal-borne devices to record physiological variables, are entering a new era driven by advances in sensor development. However, existing datasets collected with traditional bio-loggers, such as accelerometers, still contain untapped eco-physiological information. Here we present a computational method for extracting heartrate from high-resolution accelerometer data using a ballistocardiogram. We validated our method with simultaneous accelerometer-electrocardiogram tag deployments in a controlled setting on a killer whale (Orcinus orca) and demonstrate the method recovers previously observed cardiovascular patterns in a blue whale (Balaenoptera musculus), including the magnitude of apneic bradycardia and increase in heart rate prior to and during ascent. Our ballistocardiogram method may be applied to mine heart rates from previously collected accelerometery and expand our understanding of comparative cardiovascular physiology.
OBJECTIVE To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and w... more OBJECTIVE To compare serum cardiac troponin I (cTnI) concentrations between sea otters with and without cardiomyopathy and describe 2 cases of cardiomyopathy with different etiologies. ANIMALS 25 free-ranging southern sea otters (Enhydra lutris nereis) with (n = 14; cases) and without (11; controls) cardiomyopathy and 17 healthy managed southern sea otters from aquariums or rehabilitation centers (controls). PROCEDURES Serum cTnI concentration was measured in live sea otters. Histopathologic and gross necropsy findings were used to classify cardiomyopathy status in free-ranging otters; physical examination and echocardiography were used to assess health status of managed otters. Two otters received extensive medical evaluations under managed care, including diagnostic imaging, serial cTnI concentration measurement, and necropsy. RESULTS A significant difference in cTnI concentrations was observed between cases and both control groups, with median values of 0.279 ng/mL for cases and ...
Dietary cation-anion difference may explain why ammonium Dietary cation-anion difference may expl... more Dietary cation-anion difference may explain why ammonium Dietary cation-anion difference may explain why ammonium urate nephrolithiasis occurs more frequently in common urate nephrolithiasis occurs more frequently in common bottlenose dolphins (bottlenose dolphins (Tursiops truncatus Tursiops truncatus) under human care than) under human care than in free-ranging common bottlenose dolphins in free-ranging common bottlenose dolphins
SummaryEpigenetics has hitherto been studied and understood largely at the level of individual or... more SummaryEpigenetics has hitherto been studied and understood largely at the level of individual organisms. Here, we report a multi-faceted investigation of DNA methylation across 11,117 samples from 176 different species. We performed an unbiased clustering of individual cytosines into 55 modules and identified 31 modules related to primary traits including age, species lifespan, sex, adult species weight, tissue type and phylogenetic order. Analysis of the correlation between DNA methylation and species allowed us to construct phyloepigenetic trees for different tissues that parallel the phylogenetic tree. In addition, while some stable cytosines reflect phylogenetic signatures, others relate to age and lifespan, and in many cases responding to anti-aging interventions in mice such as caloric restriction and ablation of growth hormone receptors. Insights uncovered by this investigation have important implications for our understanding of the role of epigenetics in mammalian evolutio...
Background Pacific walruses are found in Arctic regions of the Chukchi and Bering Sea where rapid... more Background Pacific walruses are found in Arctic regions of the Chukchi and Bering Sea where rapid changes in environmental conditions resulting in loss of sea ice are occurring. Therefore, accurate life history data are crucial for species management plans and longitudinal data collected over the lives of individual walruses housed in zoos and aquaria provide otherwise difficult to obtain biological information. Results While similar at birth, Gompertz regression curves indicated that males grew faster than females (p < 0.0001) in weight (99 kg vs 57.6 kg/y) and length (26.9 cm vs 26.3 cm/y) with physical differences being detected by age 3 for weight and age 7 for length. Males reached adult weight at 13.5 ± 3.3 y and females by age 12.3 ± 2.3 y. The mean age at first ovulation and at first conception occurred at 8.8 y and 9.6 y. Greater than 75% of all conceptions and calving occurred between February and March and from May to June, respectively. Mean gestation lasted 423 d and...
This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plas... more This investigation compared the fatty acid (FA) levels found in erythrocyte (RBC) membranes, plasma, whole blood (WB), and blubber from wild Alaskan (Bristol Bay) belugas (Delphinapterus leucas) (BBB, n = 9) with oceanaria-based belugas (OBB, n = 14) fed a controlled diet consisting of primarily herring (Clupea harengus) and capelin (Mallotus villosus). FA patterns in RBCs, WB, and plasma varied considerably between BBB and OBB animals. Focusing on RBC FA levels of known dietary origin, the OBBs had markedly higher levels of 20:1n9,11 and 22:1n9,11. RBC levels of these fatty acids were 1% and 0.2% in the BBBs, but 8.2% and 4.5%, respectively, in the OBBs (p < 0.05 both). These long-chain mono-unsaturated FAs (LC-MUFAs) are rich in herring and capelin but not in the prey species (i.e., salmonids, smelt, cod, and shrimp) generally available to BBBs. As for the marine omega-3 poly-unsaturated fatty acids [PUFAs; 20:5n3 (eicosapentaenoic acid) and 22:6n3 (docosahexaenoic acid)], the ...
Abstract: The pharmacokinetics of danofloxacin was investigated in rehabilitated California brown... more Abstract: The pharmacokinetics of danofloxacin was investigated in rehabilitated California brown pelicans (Pelecanus occidentalis californicus) after a single intramuscular injection at a dose of 15 mg/kg body weight. The concentration of the drug in plasma was assayed by high-pressure liquid chromatography. A sparse-sampling design was used to reduce the number of samples (1–4 venipunctures) obtained from 24 brown pelicans. A population pharmacokinetic analysis with nonlinear mixed-effects modeling was used to accommodate the sparse-sampling strategy. The nonlinear mixed-effects modeling approach measured both fixed effects (typical values for the population) and random effects (between-subject variability) for this population. A 1-compartment model best represented the concentration-versus-time data after injection. After injection, the elimination half-life, peak concentration, area under the curve, and volume of distribution were 2.76 hours, 2.5 µg/mL, 13.75 µg/h/mL, and 4.35 L/kg, respectively. Rate of absorption was highly variable among the birds. The intramuscular injection of danofloxacin in pelicans at this dose produced plasma concentrations that meet therapeutic targets for bacteria with a minimum inhibitory concentration of ≤0.25 µg/mL. This dose can be used for future studies to evaluate the efficacy of danofloxacin for treating susceptible bacteria.
A juvenile female California sea lion (Zalophus californianus) presented with a firm subcutaneous... more A juvenile female California sea lion (Zalophus californianus) presented with a firm subcutaneous mass in the right caudoventral pelvic region, measuring approximately 15 3 15 cm, and edema in the right hind flipper. The initial diagnostic workup included an ultrasound, blood analysis, and fine-needle aspirate of the mass under manual restraint. While the blood analysis was within normal limits, the ultrasound revealed a large discrete hyperechoic homogeneous mass with anastomosing hypoechoic fluid pockets that, when aspirated, was suggestive of a reactive lymph node. Short-term empiric antibiotic therapy prescribed to address possible lymphadenitis yielded no response, and edema of the right hind flipper and perianal region worsened. The sea lion was anesthetized to facilitate a more thorough exam, repeat blood analysis, obtain survey radiographs, evaluate with ultrasound, and perform biopsy of mass. The thoracic radiographs were normal; however, the large radiopaque mass was observed cranial to the pelvis on lateral abdominal view and appeared solitary on ultrasound. An exploratory surgery was performed to completely excise the mass. On histopathologic review, the mass demonstrated diffuse fibrous hyperplasia of lobular ducts of the mammary gland and mild mastitis, characterizing it as a mammary fibroadenoma. The surgical wound healed within 6 wk, and there was no recurrence of mammary hyperplasia.
For many reptile species, adequate ultraviolet B (UVB) radiation is essential for proper calcium ... more For many reptile species, adequate ultraviolet B (UVB) radiation is essential for proper calcium metabolism. In this study, the effects of UVB radiation on calcium metabolism were evaluated in green sea turtles (Chelonia mydas). 25-Hydroxyvitamin D, parathyroid hormone (PTH), and ionized calcium (iCa) were measured in juvenile (n = 18, 9 indoor, 9 outdoor) and adult (n = 8, 4 indoor, 4 outdoor) turtles. All animals were fed an identical diet. Outdoor animals had access to unfiltered sunlight, whereas indoor animals were housed under artificial lighting without UVB. Mean values for 25-hydroxyvitamin D for the outdoor and indoor groups were 34.33 ± 7.98 nmol/L and 7.11 ± 1.69 nmol/L for juveniles and 73.25 ± 30.34 nmol/L and 14.0 ± 11.52 nmol/L for adults respectively. Mean values for iCa for the outdoor and indoor groups were 0.98 ± 0.07 mmol/L and 0.99 ± 0.06 mmol/L for juveniles and 1.18 ± 0.22 mmol/L and 0.97 ± 0.18 mmol/L for adults respectively. UVB exposure (P < 0.001) and age (P < 0.001) had a significant effect on 25-hydroxyvitamin D as well as a significant interaction between the two variables (P = 0.008), with highest values in adult outdoor turtles. There was a significant interaction between age group and UVB status for iCa (P = 0.036), with greater values in older outdoor turtles. 25-Hydroxyvitamin D and total calcium were positively correlated, rs = 0.39, P = 0.042. iCa and calcium-to-phosphorus ratios were also positively correlated, rs = 0.42, P = 0.027. These results suggest that UVB exposure is an important source of 25-hydroxyvitamin D for green sea turtles and has significant effects on calcium metabolism in this species. PTH values in this study were near the minimum limits of detection and suggest that current mammalian-based PTH assays are not valid for reptiles.
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