Centralized red muscle in Odontaspis ferox and the prevalence of regional endothermy in sharks.

The order Lamniformes contains charismatic species such as the white shark Carcharodon carcharias and extinct megatooth shark Otodus megalodon, and is of particular interest given their influence on marine ecosystems, and because some members exhibit regional endothermy. However, there remains significant debate surrounding the prevalence and evolutionary origin of regional endothermy in the order, and therefore the development of phenomena such as gigantism and filter-feeding in sharks generally. Here we show a basal lamniform shark, the smalltooth sand tiger shark Odontaspis ferox, has centralized skeletal red muscle and a thick compact-walled ventricle; anatomical features generally consistent with regionally endothermy. This result, together with the recent discovery of probable red muscle endothermy in filter feeding basking sharks Cetorhinus maximus, suggests that this thermophysiology is more prevalent in the Lamniformes than previously thought, which in turn has implications for understanding the evolution of regional endothermy, gigantism, and extinction risk of warm-bodied shark species both past and present.

Northerly range expansion and first confirmed records of the smalltooth sand tiger shark, Odontaspis ferox, in the United Kingdom and Ireland.

Three Odontaspis ferox (confirmed by mtDNA barcoding) were found in the English Channel and Celtic Sea in 2023 at Lepe, UK (50.7846, -1.3508), Kilmore Quay, Ireland (52.1714, -6.5937), and Lyme Bay, UK (50.6448, -2.9302). These are the first records of O. ferox in either country, and extend the species' range by over three degrees of latitude, to >52° N. They were ~275 (female), 433 (female), and 293 cm (male) total length, respectively. These continue a series of new records, possibly indicative of a climate change-induced shift in the species' range.

Somatic mutation rates scale with lifespan across mammals.

The rates and patterns of somatic mutation in normal tissues are largely unknown outside of humans1-7. Comparative analyses can shed light on the diversity of mutagenesis across species, and on long-standing hypotheses about the evolution of somatic mutation rates and their role in cancer and ageing. Here we performed whole-genome sequencing of 208 intestinal crypts from 56 individuals to study the landscape of somatic mutation across 16 mammalian species. We found that somatic mutagenesis was dominated by seemingly endogenous mutational processes in all species, including 5-methylcytosine deamination and oxidative damage. With some differences, mutational signatures in other species resembled those described in humans8, although the relative contribution of each signature varied across species. Notably, the somatic mutation rate per year varied greatly across species and exhibited a strong inverse relationship with species lifespan, with no other life-history trait studied showing a comparable association. Despite widely different life histories among the species we examined-including variation of around 30-fold in lifespan and around 40,000-fold in body mass-the somatic mutation burden at the end of lifespan varied only by a factor of around 3. These data unveil common mutational processes across mammals, and suggest that somatic mutation rates are evolutionarily constrained and may be a contributing factor in ageing.

Novel Presentation of DMV-Associated Encephalitis in a Long-Finned Pilot Whale (Globicephala melas).

Cetacean morbillivirus (CeMV) is an important global cause of morbidity and mortality in cetacean populations, with four pathological presentations including non-suppurative encephalitis. We describe an unusual case of dolphin morbillivirus (DMV)-associated non-suppurative encephalitis in a long-finned pilot whale (Globicephala melas), in which the lesions were orientated on the periventricular white matter and comprised prominent multifocal syncytia formation in the absence of systemic lesions. DMV RNA was detected in brain tissue by qRT-PCR and immunohistochemistry for morbillivirus antigen yielded intense labelling of syncytia in periventricular sites, with sparse involvement of the deeper neuroparenchyma. The pattern of lesions raises the possibility of viral dissemination through the cerebrospinal fluid, as described for canine distemper virus, suggesting that similar pathogenic mechanisms may be implicated in lesion development. Further investigation is required to establish the pathogenesis of CeMV encephalitis and the behaviour of the virus within the central nervous system of cetaceans.

Reservoir frogs: seasonality of Batrachochytrium dendrobatidis infection in robber frogs in Dominica and Montserrat.

Emerging infectious diseases are an increasingly important threat to wildlife conservation, with amphibian chytridiomycosis, caused by Batrachochytrium dendrobatidis, the disease most commonly associated with species declines and extinctions. However, some amphibians can be infected with B. dendrobatidis in the absence of disease and can act as reservoirs of the pathogen. We surveyed robber frogs (Eleutherodactylus spp.), potential B. dendrobatidis reservoir species, at three sites on Montserrat, 2011-2013, and on Dominica in 2014, to identify seasonal patterns in B. dendrobatidis infection prevalence and load (B. dendrobatidis genomic equivalents). On Montserrat there was significant seasonality in B. dendrobatidis prevalence and B. dendrobatidis load, both of which were correlated with temperature but not rainfall. B. dendrobatidis prevalence reached 35% in the cooler, drier months but was repeatedly undetectable during the warmer, wetter months. Also, B. dendrobatidis prevalence significantly decreased from 53.2% when the pathogen emerged on Montserrat in 2009 to a maximum 34.8% by 2011, after which it remained stable. On Dominica, where B. dendrobatidis emerged seven years prior to Montserrat, the same seasonal pattern was recorded but at lower prevalence, possibly indicating long-term decline. Understanding the dynamics of disease threats such as chytridiomycosis is key to planning conservation measures. For example, reintroductions of chytridiomycosis-threatened species could be timed to coincide with periods of low B. dendrobatidis infection risk, increasing potential for reintroduction success.

Apparent absence of Batrachochytrium salamandrivorans in wild urodeles in the United Kingdom.

Whether an infectious disease threat to wildlife arises from pathogen introduction or the increased incidence of an already-present agent informs mitigation policy and actions. The prior absence of a pathogen can be difficult to establish, particularly in free-living wildlife. Subsequent to the epidemic emergence of the fungus, Batrachochytrium salamandrivorans (Bsal), in mainland Europe in 2010 and prior to its detection in captive amphibians in the United Kingdom (UK), we tested archived skin swabs using a Bsal-specific qPCR. These samples had been collected in 2011 from 2409 wild newts from ponds across the UK. All swabs were negative for Bsal. Bayesian hierarchical modelling suggests that Bsal was absent from, or present at very low levels in, these ponds at the time of sampling. Additionally, surveillance of newt mortality incidents, 2013-2017, failed to detect Bsal. As this pathogen has been shown to be widespread in British captive amphibian collections, there is an urgent need to raise awareness of the importance of effective biosecurity measures, especially amongst people with captive amphibians, to help minimise the risk of Bsal spreading to the wild. Continued and heightened wild amphibian disease surveillance is a priority to provide an early warning system for potential incursion events.

Beached bachelors: An extensive study on the largest recorded sperm whale Physeter macrocephalus mortality event in the North Sea.

Between the 8th January and the 25th February 2016, the largest sperm whale Physeter macrocephalus mortality event ever recorded in the North Sea occurred with 30 sperm whales stranding in five countries within six weeks. All sperm whales were immature males. Groups were stratified by size, with the smaller animals stranding in the Netherlands, and the largest in England. The majority (n = 27) of the stranded animals were necropsied and/or sampled, allowing for an international and comprehensive investigation into this mortality event. The animals were in fair to good nutritional condition and, aside from the pathologies caused by stranding, did not exhibit significant evidence of disease or trauma. Infectious agents were found, including various parasite species, several bacterial and fungal pathogens and a novel alphaherpesvirus. In nine of the sperm whales a variety of marine litter was found. However, none of these findings were considered to have been the primary cause of the stranding event. Potential anthropogenic and environmental factors that may have caused the sperm whales to enter the North Sea were assessed. Once sperm whales enter the North Sea and head south, the water becomes progressively shallower (<40 m), making this region a global hotspot for sperm whale strandings. We conclude that the reasons for sperm whales to enter the southern North Sea are the result of complex interactions of extrinsic environmental factors. As such, these large mortality events seldom have a single ultimate cause and it is only through multidisciplinary, collaborative approaches that potentially multifactorial large-scale stranding events can be effectively investigated.

PCB pollution continues to impact populations of orcas and other dolphins in European waters.

Organochlorine (OC) pesticides and the more persistent polychlorinated biphenyls (PCBs) have well-established dose-dependent toxicities to birds, fish and mammals in experimental studies, but the actual impact of OC pollutants on European marine top predators remains unknown. Here we show that several cetacean species have very high mean blubber PCB concentrations likely to cause population declines and suppress population recovery. In a large pan-European meta-analysis of stranded (n = 929) or biopsied (n = 152) cetaceans, three out of four species:- striped dolphins (SDs), bottlenose dolphins (BNDs) and killer whales (KWs) had mean PCB levels that markedly exceeded all known marine mammal PCB toxicity thresholds. Some locations (e.g. western Mediterranean Sea, south-west Iberian Peninsula) are global PCB "hotspots" for marine mammals. Blubber PCB concentrations initially declined following a mid-1980s EU ban, but have since stabilised in UK harbour porpoises and SDs in the western Mediterranean Sea. Some small or declining populations of BNDs and KWs in the NE Atlantic were associated with low recruitment, consistent with PCB-induced reproductive toxicity. Despite regulations and mitigation measures to reduce PCB pollution, their biomagnification in marine food webs continues to cause severe impacts among cetacean top predators in European seas.

Reproductive Failure in UK Harbour Porpoises Phocoena phocoena: Legacy of Pollutant Exposure?

Reproductive failure in mammals due to exposure to polychlorinated biphenyls (PCBs) can occur either through endocrine disrupting effects or via immunosuppression and increased disease risk. To investigate further, full necropsies and determination of summed 25 polychlorinated biphenyls congeners (∑PCBs lipid weight) in blubber were undertaken on 329 UK-stranded female harbour porpoises (1990-2012). In sexually mature females, 25/127 (19.7%) showed direct evidence of reproductive failure (foetal death, aborting, dystocia or stillbirth). A further 21/127 (16.5%) had infections of the reproductive tract or tumours of reproductive tract tissues that could contribute to reproductive failure. Resting mature females (non-lactating or non-pregnant) had significantly higher mean ∑PCBs (18.5 mg/kg) than both lactating (7.5 mg/kg) and pregnant females (6 mg/kg), though not significantly different to sexually immature females (14.0 mg/kg). Using multinomial logistic regression models ΣPCBs was found to be a significant predictor of mature female reproductive status, adjusting for the effects of confounding variables. Resting females were more likely to have a higher PCB burden. Health status (proxied by "trauma" or "infectious disease" causes of death) was also a significant predictor, with lactating females (i.e. who successfully reproduced) more likely to be in good health status compared to other individuals. Based on contaminant profiles (>11 mg/kg lipid), at least 29/60 (48%) of resting females had not offloaded their pollutant burden via gestation and primarily lactation. Where data were available, these non-offloading females were previously gravid, which suggests foetal or newborn mortality. Furthermore, a lower pregnancy rate of 50% was estimated for "healthy" females that died of traumatic causes of death, compared to other populations. Whether or not PCBs are part of an underlying mechanism, we used individual PCB burdens to show further evidence of reproductive failure in the North-east Atlantic harbour porpoise population, results that should inform conservation management.

Helicobacter cetorum infection in striped dolphin (Stenella coeruleoalba), Atlantic white-sided dolphin (Lagenorhynchus acutus), and short-beaked common dolphin (Delphinus delphus) from the southwest coast of England.

Helicobacter infection in cetaceans was first reported from the US in 2000 when the isolation of a novel Helicobacter species was described from two Atlantic white-sided dolphins (Lagenorhynchus acutus). Since then, Helicobacter species have been demonstrated in cetaceans and pinnipeds from around the world. Since 1990, the Animal Health and Veterinary Laboratories Agency Polwhele, Truro, has been involved in the UK Cetacean Strandings Investigation Programme to establish the cause of death of cetacean species stranded along the coast of Cornwall, England. We describe the isolation of Helicobacter cetorum in a striped dolphin (Stenella coeruleoalba) and evidence of H. cetorum infection in cetaceans from European waters.

Meningoencephalitis and arthritis associated with Brucella ceti in a short-beaked common dolphin (Delphinus delphis).

Brucella species infection in marine mammal species has been reported to have a global distribution. In 2007, the description of Brucella ceti was published and formally adopted for those isolates originating from cetaceans and pathologic lesions similar to those seen in terrestrial mammals infected with Brucella spp. have been associated with its isolation. Brucella ceti infection specific to the central nervous system has been described in two species of cetacean: striped dolphins (Stenella coeruleoalba) in Europe and Costa Rica and an Atlantic white-sided dolphin (Lagenorhynchus acutus) in the UK. We describe the first report, to our knowledge, of B. ceti-associated meningitis and arthritis in a third species, the short-beaked common dolphin (Delphinus delphis), in an animal that stranded in the UK.

What caused the UK's largest common dolphin (Delphinus delphis) mass stranding event?

On 9 June 2008, the UK's largest mass stranding event (MSE) of short-beaked common dolphins (Delphinus delphis) occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury. Auditory tissues were grossly normal (26/26) but had microscopic haemorrhages (5/5) and mild otitis media (1/5) in the freshest cases. Five lactating adult dolphins, one immature male, and one immature female tested were free of harmful algal toxins and had low chemical pollutant levels. Pathological evidence of mud/seawater inhalation (11/26), local tide cycle, and the relative lack of renal myoglobinuria (26/26) suggested MSE onset on a rising tide between 06:30 and 08∶21 hrs (9 June). Potential causes excluded or considered highly unlikely included infectious disease, gas/fat embolism, boat strike, by-catch, predator attack, foraging unusually close to shore, chemical or algal toxin exposure, abnormal weather/climatic conditions, and high-intensity acoustic inputs from seismic airgun arrays or natural sources (e.g., earthquakes). International naval exercises did occur in close proximity to the MSE with the most intense part of the exercises (including mid-frequency sonars) occurring four days before the MSE and resuming with helicopter exercises on the morning of the MSE. The MSE may therefore have been a "two-stage process" where a group of normally pelagic dolphins entered Falmouth Bay and, after 3-4 days in/around the Bay, a second acoustic/disturbance event occurred causing them to strand en masse. This spatial and temporal association with the MSE, previous associations between naval activities and cetacean MSEs, and an absence of other identifiable factors known to cause cetacean MSEs, indicates naval activity to be the most probable cause of the Falmouth Bay MSE.

Investigating links between polychlorinated biphenyl (PCB) exposure and thymic involution and thymic cysts in harbour porpoises (Phocoena phocoena).

The associations between polychlorinated biphenyls (PCBs) exposure and involution of lymphoid tissue and development of epithelial-lined cysts in the thymus of UK-stranded harbour porpoises (Phocoena phocoena) (n=170) were tested. Percentage of thymic lymphoid tissue (%TLT) was histologically quantified. Multiple regression analyses (n=169) demonstrated significant positive correlation between %TLT and nutritional status (p<0.001) and significant negative association between %TLT and onset of sexual maturity (p<0.001). However, in a subgroup of porpoises with total PCB levels above a proposed threshold of toxicity (>17mg/kg lipid weight) (n=109), the negative association between %TLT (as dependent variable) and summed blubber concentrations of 25 chlorobiphenyl congeners (∑25CBs) remained significant (p<0.01) along with nutritional status (p<0.001) and onset of sexual maturity (p<0.001). These results suggest PCB-induced immuno suppression may be occurring in harbour porpoises in UK waters but only at concentrations that exceed proposed toxicity thresholds for marine mammals. In contrast, development of thymic cysts appears predominantly age-related.

Emerging infectious disease leads to rapid population declines of common British birds.

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period.

Lumbopelvic manipulation for the treatment of patients with patellofemoral pain syndrome: development of a clinical prediction rule.

STUDY DESIGN: Prospective cohort/predictive validity study. OBJECTIVE: To determine the predictive validity of selected clinical exam items and to develop a clinical prediction rule (CPR) to determine which patients with patellofemoral pain syndrome (PFPS) have a positive immediate response to lumbopelvic manipulation. BACKGROUND: Quadriceps muscle function in patients with PFPS was recently shown to improve following treatment with lumbopelvic manipulation. No previous study has determined if individuals with PFPS experience symptomatic relief of activity-related pain immediately following this manipulation technique. METHODS AND MEASURES: Fifty subjects (26 male, 24 female; age range, 18-45 years) with PFPS underwent a standardized history and physical examination. After the evaluation, each subject performed 3 typically pain-producing functional activities (squatting, stepping up a 20-cm step, and stepping down a 20-cm step). The pain level perceived during each activity was rated on a numerical pain scale (0 representing no pain and 10 the worst possible pain). Following the assessment, all subjects were treated with a lumbopelvic manipulation, which was immediately followed by retesting the 3 functional activities to determine if there was any change in pain ratings. An immediate overall 50% or greater reduction in pain, or moderate or greater improvement on a global rating of change questionnaire, was considered a treatment success. Likelihood ratios (LRs) were calculated to determine which examination items were most predictive of treatment outcome. RESULTS: Data for 49 subjects were included in the data analysis, of which 22 (45%) had a successful outcome. Five predictor variables were identified. The most powerful predictor of treatment success was a side-to-side difference in hip internal rotation range of motion greater than 14 masculine (+LR, 4.9). If this variable was present, the chance of experiencing a successful outcome improved from 45% to 80%. CONCLUSION: A CPR was developed to predict an immediate successful response to lumbopelvic manipulation in patients with PFPS. However, in light of a limited sample size and omission of potentially meaningful predictor variables, future studies are necessary to validate the CPR.

The emerging amphibian pathogen Batrachochytrium dendrobatidis globally infects introduced populations of the North American bullfrog, Rana catesbeiana.

Batrachochytrium dendrobatidis is the chytridiomycete fungus which has been implicated in global amphibian declines and numerous species extinctions. Here, we show that introduced North American bullfrogs (Rana catesbeiana) consistently carry this emerging pathogenic fungus. We detected infections by this fungus on introduced bullfrogs from seven of eight countries using both PCR and microscopic techniques. Only native bullfrogs from eastern Canada and introduced bullfrogs from Japan showed no sign of infection. The bullfrog is the most commonly farmed amphibian, and escapes and subsequent establishment of feral populations regularly occur. These factors taken together with our study suggest that the global threat of B. dendrobatidis disease transmission posed by bullfrogs is significant.