Mortality of dolphins in fishing operations is often under-estimated, as shown by studies of beach-washed carcasses. Linking evidence obtained during necropsies with fishing method is fundamental to understanding the extent of mortality and the manner in which animals die. The South Australian Sardine Fishery (SASF) has operated a purse-seine industry since 1991.
View Article and Find Full Text PDFWildlife species are challenged by various infectious diseases that act as important demographic drivers of populations and have become a great conservation concern particularly under growing environmental changes. The new era of whole genome sequencing provides new opportunities and avenues to explore the role of genetic variants in the plasticity of immune responses, particularly in non-model systems. Cetacean morbillivirus (CeMV) has emerged as a major viral threat to cetacean populations worldwide, contributing to the death of thousands of individuals of multiple dolphin and whale species.
View Article and Find Full Text PDFInformation about pollution and its potential impact in Australian marine wildlife is scarce. To fill this knowledge gap, our study investigated concentrations of legacy pollutants as well as naturally produced methoxylated polybrominated diphenyl ethers (MeO-PBDEs) in blubber, liver, kidney and muscle of Indo-Pacific bottlenose dolphins (Tursiops aduncus) from two large inverse estuaries in South Australia from 1989 to 1995 and 2009-2014. Our results show that concentrations of most pollutant classes are relatively low compared to the literature but at the higher end of the ranges reported for marine mammals in Australia.
View Article and Find Full Text PDFInfectious diseases are significant demographic and evolutionary drivers of populations, but studies about the genetic basis of disease resistance and susceptibility are scarce in wildlife populations. Cetacean morbillivirus (CeMV) is a highly contagious disease that is increasing in both geographic distribution and incidence, causing unusual mortality events (UME) and killing tens of thousands of individuals across multiple cetacean species worldwide since the late 1980s. The largest CeMV outbreak in the Southern Hemisphere reported to date occurred in Australia in 2013, where it was a major factor in a UME, killing mainly young Indo-Pacific bottlenose dolphins ().
View Article and Find Full Text PDFStudies of skeletal pathology of marine mammals can contribute to conservation measures, yet few have focused on causative factors. Museums hold vast collections of skeletons relevant to this knowledge gap. Indo-Pacific bottlenose dolphin Tursiops aduncus carcasses (n = 162) were collected from Gulf St Vincent (GSV) and Spencer Gulf (SG), South Australia (SA), between 1988 and 2013, and post-mortem examinations were carried out.
View Article and Find Full Text PDFSelenium as an antioxidant has attracted attention because of its anticancer activity. This review presents a view on selenium and its compounds exerting influence against cancer in the soft tissues. The results reveal a significant strong association between a low selenium level in blood and a cancer risk.
View Article and Find Full Text PDFCases of morbillivirus have been recorded in the Southern Hemisphere but have not been linked to significant marine mammal mortality. Post-mortems were conducted on 58 carcasses (44 Indo-Pacific bottlenose dolphins, two common bottlenose dolphins, 12 short-beaked common dolphins) from South Australia during 2005-2013, including an unusual mortality event (UME) in St Vincent Gulf Bioregion (SVG) during 2013. Diagnostic pathology, circumstance of death, body condition, age and stomach contents were documented for Indo-Pacific bottlenose dolphins.
View Article and Find Full Text PDFWe review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus.
View Article and Find Full Text PDFBetween 1990 and 2007, carcasses of opportunistically collected short-beaked common dolphins (Delphinus delphis; n=238), Indo-Pacific bottlenose dolphins (Tursiops aduncus; n=167), and common bottlenose dolphins (Tursiops truncatus; n=15) were examined for parasites and life history data. Three species of lung nematodes (Halocercus lagenorhynchi, Stenurus ovatus, Pharurus alatus) were identified in surface nodules, subsurface lesions, or airways. Nematode burdens were light to heavy and, in many cases, would have compromised the dolphins' health.
View Article and Find Full Text PDFNecropsy examination of dolphins living in Gulf St Vincent, Australia is routinely undertaken to enable the evaluation of disease processes and to provide rapid medicolegal assessment of any inflicted and/or accidental injuries. Two Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) are reported to demonstrate conditions that may result in unexpected death involving upper airway compromise by quite unusual mechanisms. In the first case an adult male was found with extensive soft tissue trauma suggesting human interaction.
View Article and Find Full Text PDFThe hearing organ contains sensory hair cells, which convert sound-evoked vibration into action potentials in the auditory nerve. This process is greatly enhanced by molecular motors that reside within the outer hair cells, but the performance also depends on passive mechanical properties, such as the stiffness, mass, and friction of the structures within the organ of Corti. We used resampled confocal imaging to study the mechanical properties of the low-frequency regions of the cochlea.
View Article and Find Full Text PDFWe describe a novel confocal image acquisition system capable of measuring the sound-evoked motion of the organ of Corti. The hearing organ is imaged with a standard laser scanning confocal microscope during sound stimulation. The exact temporal relation between each image pixel and the sound stimulus is quantified.
View Article and Find Full Text PDFConfocal laser scanning microscopy permits detailed visualization of structures deep within thick fluorescently labeled specimen. This makes it possible to investigate living cells inside intact tissue without prior chemical sample fixation and sectioning. Isolated guinea pig temporal bones have previously been used for confocal experiments in vitro, but tissue deterioration limits their use to a few hours after the death of the animal.
View Article and Find Full Text PDFThe great-gray kangaroo (Macropus giganteus) belongs to the Diprotodontia suborder (herbivorous marsupials of Australia) of the order of marsupials. We dissected the masticatory muscles in the great-gray kangaroo and classified them based on their innervation. Three (two male and one female) adult great-gray kangaroos (M.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2006
The cochlea contains two types of sensory cells, the inner and outer hair cells. Sound-evoked deflection of outer hair cell stereocilia leads to fast force production that will enhance auditory sensitivity up to 1,000-fold. In contrast, inner hair cells are thought to have a purely receptive function.
View Article and Find Full Text PDFVisualizing deep inside the tissue of a thick biological sample often poses severe constraints on image conditions. Standard restoration techniques (denoising and deconvolution) can then be very useful, allowing one to increase the signal-to-noise ratio and the resolution of the images. In this paper, we consider the problem of obtaining a good determination of the point-spread function (PSF) of a confocal microscope, a prerequisite for applying deconvolution to three-dimensional image stacks acquired with this system.
View Article and Find Full Text PDFPublished descriptions of the buccinator muscle of the cat (Felis domestica) differ from those for the same muscle in other mammals. Only an oral component of the muscle has been described in cats, not a buccal part. The purpose of this study was to identify the buccinator muscle in the cat and report on its anatomical features in detail.
View Article and Find Full Text PDFAlthough the human digastric muscle is classified as a suprahyoid muscle, none of the digastric muscles in other mammals are classed as suprahyoid in textbooks of veterinary anatomy. The aim of this study was to describe the anatomical relationship of the digastric muscle in a marsupial, the kangaroo, and to consider factors thought to be important in leading to the different position of the muscle in quadrupeds compared with humans. Eight heads of the common wallaroo (Macropus robustus) were used in this study.
View Article and Find Full Text PDFBackground: The mammalian mandible develops around Meckel's cartilage and other secondary cartilages, including the dentary. There have already been many studies of the development of the rat mandible that have employed histological serial sections. However, no previous investigators have captured the three-dimensional features of the developmental process.
View Article and Find Full Text PDFThe number of heads possessed by the lateral pterygoid muscle was investigated in the dog. Only a single head was observed which it is suggested may correspond to the lower head in other mammals. It inserted both onto the condyle and into the articular disc.
View Article and Find Full Text PDFThe occurrence of a cleidocervical muscle, which arose from the anterior tubercle of the transverse process of the 6th cervical vertebra and was inserted onto the superior margin of the clavicle, is described. Detailed observations on its innervation, which was derived from the 5th cervical nerve, and its topographic anatomy suggest that the muscle originated from longus colli.
View Article and Find Full Text PDFThe masticatory muscles and their innervations in dogs are classified, from deep to superficial layers, as follows: 1) medial pterygoid muscle and medial pterygoid nerve, 2) lateral pterygoid muscle and lateral pterygoid nerve, 3) anterior deep part of temporal muscle and anterior deep temporal nerve, 4) posterior deep part of temporal muscle and posterior deep temporal nerve, 5) superficial part of temporal muscle and superficial temporal nerve, the only branch of the temporal nerve which passes out from the infratemporal fossa, 6) zygomaticomandibular part of masseter muscle, which is thought to belong to the masseter muscle, and masseter nerve, 7) deep layer of masseter muscle and masseter nerve, 8) superficial layer of masseter muscle and masseter nerve.
View Article and Find Full Text PDFOne of the still open questions of teratology is the relationship between experimental teratological investigations and their validity in human medicine. The aetiology of the development of inborn developmental defects comprises factors the ratio of which is the subject of discussions. The category of still unknown factors is the largest one.
View Article and Find Full Text PDFBratisl Lek Listy
February 1990
Of the history of the Institute for General Biology, School of Medicine, Comenius University, the study deals with the first period, namely the years 1923-1945. The institute greatly benefited from the activities of Prof. MUDr.
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