Explore the vast range of titles available.

Determining sex ratios of endangered populations is important for wildlife management, particularly species subject to sex-specific threats or that exhibit temperature-dependent sex determination. Sea turtle sex is determined by incubation temperature and individuals lack external sex-based traits until sexual maturity. Previous research utilized serum/plasma testosterone radioimmunoassays (RIA) to determine sex in immature/juvenile sea turtles. However, there has been a growing application of enzyme-linked immunosorbent assay (ELISA) for wildlife endocrinology studies, but no study on sea turtles has compared the results of ELISA and RIA. This study provides the first sex ratio for a threatened East Pacific green sea turtle (Chelonia mydas) foraging aggregation, a critical step for future management of this species. Here, we validate a testosterone ELISA and compare results between RIA and ELISA of duplicate samples. The ELISA demonstrated excellent correspondence with the RIA for providing testosterone concentrations for sex determination. Neither assay proved reliable for predicting the sex of reproductively active females with increased testosterone production. We then applied ELISA to examine the sex ratio of 69 green turtles foraging in San Diego Bay, California. Of 45 immature turtles sampled, sex could not be determined for three turtles because testosterone concentrations fell between the ranges for either sex (females: 4.1-113.1 pg/mL, males: 198.4-2,613.0 pg/mL) and these turtles were not subsequently recaptured to enable sex determination; using a Bayesian model to predict probabilities of turtle sex we predicted all three 'unknowns' were female (> 0.86). Additionally, the model assigned all turtles with their correct sex (if determined at recapture) with 100% accuracy. Results indicated a female bias (2.83F:1M) among all turtles in the aggregation; when focusing only on putative immature turtles the sex ratio was 3.5F:1M. With appropriate validation, ELISA sexing could be applied to other sea turtle species, and serve as a crucial conservation tool.

A comprehensive evaluation of the effects of sex, age, and season on blood analytes in a robust population size of ex situ bottlenose dolphins (Tursiops spp.) has not been investigated to date. To define the variation in hematological and biochemical analytes of dolphins due to sex, age, and season. 1,426 blood samples collected from 156 clinically normal dolphins consisting of 59 males and 97 females in which 37 analytes were measured were retrospectively identified. The dolphins were categorized by age, sex, and season, and categories were compared. About 23 (64%) analytes differed by age. The number of differences between adjacent age groups decreased with advancing age. MPV, glucose, BUN, globulins, GGT and Cl progressively increased with age, whereas Abs lymphs, total protein, ALP, CK and Ca progressively decreased with age. Three (8%) of analytes differed between sex, whereas 16 (44%) analytes differed by season. Female dolphins had higher median iron (33 µmol/L) than male dolphins (25 µmol/L). Female dolphins also had higher Abs lymphs and MCHC, but Abs lymphs and MCHC also differed between age and season, respectively. Sex inconsistently and relatively infrequently influences analytes. Delphinids of advancing age experience immune senescence and decreasing renal perfusion or clearance. These results demonstrate the importance of considering the influences of sex, age, and season on blood data, provide a baseline for accurate interpretation of clinicopathological analytes of delphinids in managed care, and will be useful for investigations into health, disease, and stressors of wild delphinids.

An adult female bottlenose dolphin (Tursiops truncatus) housed at a public oceanarium presented with acute anorexia and lethargy. A blood analysis demonstrated mild leukocytosis, marked azotemia, hyperkalemia, and hyperphosphatemia suggestive of acute kidney injury or renal insufficiency. Ultrasound examination of the dolphin revealed ascites, pleural effusion, bilateral nephrolithiasis, mild hydronephrosis, and bilateral hydroureter consistent with bilateral post-renal obstruction. Initial treatment consisted of antibiotics, oral fluids, and anti-inflammatory treatment. Further imaging diagnosed bilateral obstructing ureteroliths at both ureteral orifice junctions of the urinary bladder. The dolphin’s azotemia and hyperkalemia were nonresponsive to traditional medical management; therefore, peritoneal dialysis was performed for emergent clinical stabilization. Peritoneal dialysis was conducted over 3 days and facilitated the patient to undergo laser lithotripsy of the offending ureteral obstruction. The dolphin made a full recovery following months of intensive medical treatment for complications from peritoneal dialysis and secondary peritonitis. This is the first documented case of successful, though complicated, peritoneal dialysis in a cetacean.

Polar bears (Ursus maritimus) face a number of challenges that threaten the survival of the species. Captive breeding represents one essential facet of species conservation, but aspects of the polar bear’s reproductive physiology, such as follicle maturation, coitus-induced ovulation, and pseudopregnancy, are poorly characterized and present challenges for enhancing natural reproductive success and the application of advanced reproductive techniques. Due to the absence of a reliable transrectal or transabdominal ultrasound method for ovarian examination in the species, the ovaries of two adult female polar bears were examined laparoscopically to evaluate the feasibility of surgical access to the ovaries, oviduct, and uterus. The minimally invasive procedure was easily and rapidly performed in both bears and all procedures. Direct visual assessment of the ovary was possible after dissection of a fatty bursal sac, which completely enclosed the ovaries. In the second bear, laparoscopic manipulation of the ovary to draw it closer to the body wall enabled transcutaneous ultrasound. Laparoscopy may be a valuable tool to aid in the application of advanced reproductive technologies in polar bears.

Many wild otariids (sea lions and fur seals) strand along the California coast annually with seizures following presumed exposure to harmful algal blooms (HABs). This is a long-term case study of a stranded subadult male Guadalupe fur seal (Arctocephalus townsendi) that stranded in 2001 and within days after admission began demonstrating seizure activity. The epilepsy was stabilized with antiepileptic drug (AED) therapy and advanced imaging was performed. Magnetic resonance (MR) scans showed signs of encephalopathy consistent with domoic acid (DA) toxicosis. This fur seal was deemed “non-releasable” and over the following 19 years, he received supportive veterinary care and AED treatment at a permitted facility. In the summer of 2020, the fur seal showed progressive behavioral and functional deterioration whereupon humane euthanasia was performed. Post-mortem MR and diffusion tensor images (DTI) were acquired. A volumetric comparison with historic scans showed evidence of severe progressive unilateral right hippocampal atrophy. Histopathology confirmed severe chronic right and mild left hippocampal atrophy. The progressive degenerative brain changes demonstrate how adaptive brain function can be with neuronal atrophy secondary to DA exposure. This case highlights some considerations and decision-making processes needed for the rehabilitation and placement of wild stranded otariids with acquired epilepsy secondary to DA toxicity.

The objective of this study was to investigate the pharmacokinetics of meloxicam in bottlenose dolphins (Tursiops truncatus). Ten adult bottlenose dolphins were used for the study. Each animal received a single oral dose of meloxicam at 0.1 mg/kg. Two to seven serial blood samples were collected per animal, at one of fourteen time points between T = 0 and T = 240 hr. Complete blood count and serum chemistry analysis were performed prior to drug administration, as well as at the final time point for each individual. Plasma drug concentrations were determined by high-pressure liquid chromatography. No adverse hematological, biochemical or clinical changes were noted during the study period. After oral administration, a peak plasma concentration of 1.03 μg/mL was achieved at approximately 11 hr. This suggests that a single oral dose of 0.1 mg/kg provides a peak plasma level similar to what is considered therapeutic in other species. However, the elimination of meloxicam in cetaceans was slower than in other species, with an elimination half-life of almost 70 hr, and detectable drug concentrations up to 7 days. A single oral dose of 0.1 mg/kg appears safe for use in this species, but caution in repeated dosing must be used, due to the prolonged elimination, until multi-dose pharmacokinetic studies are determined.

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.

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 subadult female short-finned pilot whale (Globicephala macrorhynchus), which stranded on the northeastern Gulf of Mexico coast of Florida in June 2017, was rehabilitated for 38 days and then monitored with a satellite-linked, time-depth recording tag for 32 days after being released off the West Florida Shelf. The individual, \"Gale,\" appeared to regularly use ocean currents to facilitate a southeastward movement around Florida, and then a northward movement along the continental shelf break to the waters off Cape Hatteras, North Carolina. Indeed, 57% of her travel along the coast of Florida was at speeds consistent with the surface speed and direction of the Gulf Stream. Overall, current-assisted travel contributed to a 19% increase in distance traveled (4,152 km) and to an average rate of travel (130 km/d) that was higher than previously reported for Globicephala spp. Gale's dive behavior was typical of other short-finned pilot whale observations, with average dive depths (243 [+ or -] 136 m; max = 712 m) and durations (7.9 [+ or -] 2.2 min; max = 16.0 min) within the range of reported values for Globicephala spp. Gale also occupied habitats known to be used by pilot whales, and her movements and behaviors were consistent with those observed in other short-finned pilot whales in the Gulf of Mexico and the northwestern Atlantic Ocean. The information presented herein contributes to a better understanding of short-finned pilot whales and to the assessment of rehabilitation and release protocols. Key Words: post-release monitoring, tagging, tracking, dive behavior, current-assisted travel, Gulf Stream, pilot whale, Globicephala macrorhynchus

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 = 104) were analyzed from killer whales (n = 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 = 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 ± 53.6 ng/L and 30.2 ± 2.6 μg/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.