Fatal Asphyxiation in Bottlenose Dolphins (Tursiops truncatus) from the Indian River Lagoon

Multiple single case reports of asphyxiation in dolphins caused by fish lodged in the esophagus exist. However, the significance of this cause of mortality in a single population has not been documented. We performed a retrospective evaluation of pathology records from stranded bottlenose dolphins (Tursiops truncatus) from the Indian River Lagoon to evaluate the impact of this cause of death on this population. From 1997 to 2011, asphyxiation due to choking was identified as the cause of death in 14 of 350 cases (4%). Sampling of an unrelated but adjacent population over this same period yielded 186 necropsy cases of bottlenose dolphins with no cases of asphyxiation. Asphyxiated animals presented with a fish lodged in the cranial esophagus associated with a dislocated and obstructed or compressed larynx. There was no clear sex predilection. Affected animals included 12 adults and two juveniles. The fish species involved included sheepshead, black chin tilapia and striped mojarra. In five cases, recreational fishing gear was also present. Cetacean choking is related to selection of prey fish species with strong dorsal spines and may be secondarily associated with fish attached to fishing gear. Prey abundance and dolphin behavior may influence these selections. Environmental alterations leading to changes in prey availability or increased interactions with fishing gear may change the significance of fatal choking in dolphin populations.     

Disruption of lens fiber cell differentiation and survival at multiple stages by region-specific expression of truncated FGF receptors

To determine if fibroblast growth factor signaling mechanisms are required for terminal differentiation and survival of lens fiber cells, we evaluated the effects of expressing truncated fibroblast growth factor receptors (tFGFRs) in different regions of the developing lens. Two sets of transgenic mice were generated, one expressing tFGFRs from the alphaA-crystallin promoter (alphaA-tFGFR), which expresses linked genes in fiber cells throughout their differentiation program, and the other expressing tFGFRs from the gammaF-crystallin promoter (gammaF-tFGFR), which expresses linked genes beginning later during their differentiation. Histological and TUNEL analyses of lenses from alphaA-tFGFR and gammaF-tFGFR transgenic mice suggest that FGFR signaling is required for both early and late fiber cell differentiation and/or survival of the terminally differentiated cells. Additionally, multilayering and increased levels of apoptosis were observed in the anterior epithelium after the onset of fiber cell abnormalities. In situ hybridizations suggest that tFGFR transgenes were not expressed at significant levels in the epithelium. Combined with TUNEL and X-gal analyses on the lens epithelium from gammaF-tFGFR/Rosabeta-geo26 and nontransgenic/Rosabeta-geo26 chimeras, these results suggest that the organization and survival of the epithelial cells depend on appropriate structure and/or function of the differentiated fiber cells.     

Investigation of growth phases for bottlenose dolphins using a Bayesian modeling approach

The Gompertz function is the most commonly used growth function for cetacean studies. However, this function cannot represent multiple phases of growth. In this study, we present a Bayesian framework fitting parameters of a triple-logistic growth function to describe multiple phases of growth for bottlenose dolphins ( Tursiops truncatus ), simultaneously fitting and comparing all growth parameters between South Carolina (SC), Mississippi Sound (MSS), and Indian River Lagoon (IRL) cohorts. The fitted functions indicated a preliminary early, rapid growth phase, followed by a second phase of slower growth, and then a moderate growth spurt later in life. Growth parameters between geographic cohorts did not show obvious differences, although asymptotic length for SC dolphins was lower than MSS and IRL dolphins and significantly lower between females from SC and the IRL. Growth rate velocities between the sexes showed females exceed males initially (<1 yr), followed by males gaining an advantage around the ages of 3–4 yr until the age of around 15 yr when growth rates for both sexes approached zero (asymptotic length). This study demonstrates age-related changes in growth rates between bottlenose dolphin sexes and evidence of at least some differences ( i.e. , asymptotic length) across geographic cohorts.     

GROWTH OF BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS) FROM THE INDIAN RIVER LAGOON SYSTEM, FLORIDA, U. S. A.

Gompertz growth models were fitted to total lengths and ages from tooth sections of 199 stranded bottlenose dolphins ( Tursiops truncatus ) from the Indian River Lagoon system, eastern Florida. Based on the model, dolphins from this population are estimated to be born at 119 cm and reach asymptotic length at 250 cm. No apparent pubescent growth acceleration was noted for either sex. Males appeared to grow to slightly longer lengths than females. There were small size differences between Indian River dolphins and those in Texas and Sarasota, indicating general size similarities between North Atlantic and Gulf of Mexico bottlenose dolphins stocks.     

Obesity of mice lacking VAP-1/SSAO by Aoc3 gene deletion is reproduced in mice expressing a mutated vascular adhesion protein-1 (VAP-1) devoid of amine oxidase activity

Journal of Physiology and Biochemistry - The product of Aoc3 gene is known as vascular adhesion protein-1 (VAP-1), a glycoprotein contributing to leukocyte extravasation and exhibiting...     

Holocene Human Footprints in North America

Reports of human footprints from North American archaeological sites are summarized and described. Although some human footprints have been claimed to be of Pleistocene and earlier ages, the earliest authenticated prints in America north of Mexico, as distinct from Central or South America, date to the Holocene. The earliest of these prints is at least 5,070 years old, and the youngest are late prehistoric period, only about 400 years old. Footprint sites are reported in the U.S. Southeast, Southwest, and California. Activities indicated by ancient North American human footprints include the mundane, such as daily tasks in a riparian zone and domestic behaviors inside a habitation. Footprints were also left by prehistoric peoples undertaking more esoteric activities deep in cave interiors, including exploration, mineral extraction, and ritual.     

Skin lesions on common bottlenose dolphins (Tursiops truncatus) from three sites in the Northwest Atlantic, USA

Skin disease occurs frequently in many cetacean species across the globe; methods to categorize lesions have relied on photo-identification (photo-id), stranding, and by-catch data. The current study used photo-id data from four sampling months during 2009 to estimate skin lesion prevalence and type occurring on bottlenose dolphins (Tursiops truncatus) from three sites along the southeast United States coast [Sarasota Bay, FL (SSB); near Brunswick and Sapelo Island, GA (BSG); and near Charleston, SC (CHS)]. The prevalence of lesions was highest among BSG dolphins (P = 0.587) and lowest in SSB (P = 0.380), and the overall prevalence was significantly different among all sites (p<0.0167). Logistic regression modeling revealed a significant reduction in the odds of lesion occurrence for increasing water temperatures (OR = 0.92; 95%CI:0.906-0.938) and a significantly increased odds of lesion occurrence for BSG dolphins (OR = 1.39; 95%CI:1.203-1.614). Approximately one-third of the lesioned dolphins from each site presented with multiple types, and population differences in lesion type occurrence were observed (p<0.05). Lesions on stranded dolphins were sampled to determine the etiology of different lesion types, which included three visually distinct samples positive for herpesvirus. Although generally considered non-fatal, skin disease may be indicative of animal health or exposure to anthropogenic or environmental threats, and photo-id data provide an efficient and cost-effective approach to document the occurrence of skin lesions in free-ranging populations.     

Domoic acid exposure in pygmy and dwarf sperm whales (Kogia spp.) from southeastern and mid-Atlantic U.S. waters

The neurotoxin domoic acid (DA) was detected in urine and fecal samples recovered from pygmy sperm whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) stranding along the U.S. Atlantic coast from 1997 to 2008. Of the 41 animals analyzed from Virginia, North Carolina, South Carolina and Florida, 24 (59%) tested positive for DA at concentrations of 0.4–1.8 ng/mL in urine and 12–13,566 ng/g in feces as determined by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Feces appeared to be the best indicator of DA exposure in Kogia spp., with 87% of all fecal samples analyzed testing positive for this toxin. Additional stranded animals (n = 40) representing 11 other cetacean species were recovered from the same region between 2006 and 2008 and analyzed by LC–MS/MS, however DA was not detected in any of these individuals. DA is produced naturally by diatoms in the genus Pseudo-nitzschia. Although blooms of DA-producing Pseudo-nitzschia have been associated with repeated large-scale marine mammal mortalities on the west coast of the U.S., there is no documented history of similar blooms on the southeast U.S. coast, and there were no observed Pseudo-nitzschia blooms in the region associated with any of these strandings. The feeding habits of Kogia spp. are poorly documented; thus, the vector(s) for DA exposure to these deep-diving species remains to be identified. Toxin accumulation in these pelagic whale species may be an indication of cryptic harmful algal bloom activity in offshore areas not currently being monitored. This study highlights the need for a better understanding of the role of toxigenic algae in marine mammal morbidity and mortality globally.     

The immunomodulating effect of the microsporidan Glugea stephani on the humoral response and immunoglobulin levels in winter flounder, Pseudopleuronectes americanus

A quantitative study of serum immunoglobulin levels and haemagglutination titres has shown that an injection of the microsporidan Glugea stephani caused a decrease in the humoral response of the winter flounder. These examples demonstrate the effect of temperature on the decrease in total IgM levels and haemagglutination titres in winter flounder simultaneously injected with either G. stephani or horse red blood cells.
Transfer of serum from fish injected with spores 3 weeks earlier may also implicate soluble serum factors, such as prostaglandins or leukotrienes, causing the observed decrease in serum IgM levels.