Selective Inner Hair Cell Loss in a Neonate Harbor Seal ().

Congenital hearing loss is recognized in humans and other terrestrial species. However, there is a lack of information on its prevalence or pathophysiology in pinnipeds. It is important to have baseline knowledge on marine mammal malformations in the inner ear, to differentiate between congenital and acquired abnormalities, which may be caused by infectious pathogens, age, or anthropogenic interactions, such as noise exposure.

Cochlear apical morphology in toothed whales: Using the pairing hair cell-Deiters' cell as a marker to detect lesions.

The apex or apical region of the cochlear spiral within the inner ear encodes for low-frequency sounds. The disposition of sensory hair cells on the organ of Corti is largely variable in the apical region of mammals, and it does not necessarily follow the typical three-row pattern of outer hair cells (OHCs). As most underwater noise sources contain low-frequency components, we expect to find most lesions in the apical region of the cochlea of toothed whales, in cases of permanent noise-induced hearing loss.

Combining Cochlear Analysis and Auditory Evoked Potentials in a Beluga Whale With High-Frequency Hearing Loss.

Correlations between inner ear morphology and auditory sensitivity in the same individual are extremely difficult to obtain for stranded cetaceans. Animals in captivity and rehabilitation offer the opportunity to combine several techniques to study the auditory system and cases of hearing impairment in a controlled environment. Morphologic and auditory findings from two beluga whales () in managed care are presented.

URINARY BLADDER TRANSITIONAL CELL CARCINOMA AND CARCINOMATOSIS IN A LINNAEUS'S TWO-TOED SLOTH, .

A 19-yr-old female Linnaeus's two-toed sloth () with a history of urinary incontinence, ascites, and behavioral changes was euthanized after diagnostic imaging revealed a large bladder mass. On gross necropsy, the sloth had a severely thickened bladder mucosa, partial urinary obstruction, and nonseptic exudate in the peritoneal cavity. Histopathology showed a malignant and highly invasive transitional cell (urothelial) carcinoma with transmural and intra-abdominal invasion and diffuse carcinomatosis.

Effects of atrazine and chlorothalonil on the reproductive success, development, and growth of early life stage sockeye salmon (Oncorhynchus nerka).

The effects of 2 currently used commercial pesticide formulations on Pacific sockeye salmon (Oncorhynchus nerka), from fertilization to emergence, were evaluated in a gravel-bed flume incubator that simulated a natural streambed. Embryos were exposed to atrazine at 25 µg/L (low atrazine) or atrazine at 250 µg/L (high atrazine) active ingredient (a.i.

Cryptococcus gattii Type VGIIa Infection in Harbor Seals ( Phoca vitulina ) in British Columbia, Canada.

Cryptococcosis has been reported in marine mammals in the northeastern Pacific with increasing frequency in the last 15 yr. Although a variety of cetaceans have been diagnosed with cryptococcosis, Cryptococcus gattii has not been reported in pinnipeds. We document C.

Manufacturing doubt about endocrine disrupter science--A rebuttal of industry-sponsored critical comments on the UNEP/WHO report "State of the Science of Endocrine Disrupting Chemicals 2012".

We present a detailed response to the critique of "State of the Science of Endocrine Disrupting Chemicals 2012" (UNEP/WHO, 2013) by financial stakeholders, authored by Lamb et al. (2014). Lamb et al.

Mercury Accumulation in Harbour Seals from the Northeastern Pacific Ocean: The Role of Transplacental Transfer, Lactation, Age and Location.

Mercury (Hg) bioaccumulates in the aquatic food chain in the form of methylmercury, a compound well known for its neurotoxicity. We analyzed total mercury (THg) in hair collected from 209 harbour seals captured at 10 sites in British Columbia (Canada) and Washington State (USA) between 2003 and 2010. In addition, laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) allowed for a highly refined analysis of THg accumulation over time by examining nine whiskers taken from 4- to 6-week-old pups.

Transplacental Transfer of Polychlorinated Biphenyls, Polybrominated Diphenylethers, and Organochlorine Pesticides in Ringed Seals (Pusa hispida).

The transplacental transfer of persistent organic pollutants in marine mammals takes place at a formative developmental period, thereby exposing the fetus to endocrine-disrupting compounds. We evaluated the transplacental transfer of polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs), and organochlorine pesticides (OCPs) in five pregnant ringed seals in Northern Labrador, Canada. PCBs, PBDEs, and OCPs were transferred from the mother to the fetus with average concentrations in the fetuses ranging from 0.

Allonursing in captive belugas (Delphinapterus leucas).

This study describes allonursing (females nursing offspring that are not their own) in captive belugas (Delphinapterus leucas). In addition to the calf's mother, two females that were not pregnant or nursing at the time of the calf's birth spontaneously lactated and nursed the male calf intermittently throughout 34 months of his life at the Vancouver Aquarium Marine Science Center. These observations suggest that allonursing may also take place in their wild counterparts and add to existing evidence of alloparental care in this species.