Chronic tuberculosis caused by Mycobacterium bovis in a domestic donkey in Central Europe

Bovine tuberculosis is a contagious and zoonotic disease of animals and humans. In Europe, the number of reported cases of tuberculosis has decreased. Equidae are relatively rarely infected even in endemic areas. The presented report describes a case of chronic Mycobacterium bovis tuberculosis in a 30-year-old female donkey. The donkey initially presented with persistent lymphadenopathy; however, as the disease progressed, weight loss became apparent. To the authors' knowledge, this is the second confirmed case of tuberculosis in a donkey in Europe.     

Retrobulbar respiratory epithelial orbital cyst in a dog: A case report

A 10-month-old female, neutered French Bulldog presented with a history of unilateral right-sided intermittent conjunctivitis and exophthalmos. The patient suffered blunt force trauma to the right eye after a tennis ball impact approximately five months prior to presentation. Examination identified the patient was visual with exophthalmos, lateral strabismus, conjunctival hyperaemia, episcleral congestion, and papilloedema. Magnetic resonance imaging and ultrasonography identified an approximately two centimeter diameter fluid-filled structure directly posterior to the globe leading to displacement of the optic nerve and distortion of the posterior globe wall. Centesis of the lesion demonstrated neutrophilic and macrophagic inflammation with evidence of prior hemorrhage. Within four weeks, the structure had re-filled to its original size and was subsequently excised in its entirety, via a lateral orbitotomy. Histopathologic findings indicated a non-keratinising orbital cyst, the lining of which was consistent with a respiratory epithelial cyst. Recurrence had not occurred seven months' post-surgery. To the author's knowledge, previous reports of retrobulbar respiratory epithelial cysts have not been documented in animals.     

Variance in leaf spot susceptibility in chestnut trees of different species and hybrids

Journal of Plant Diseases and Protection - Prior to the first occurrence of chestnut blight in 1976, leaf spot caused by Cylindrosporium castaneae was one of the most important diseases of European...     

Do active‐dispersing insects dominate the invertebrate fauna of rock pools in the wet–dry tropics,Kimberley, Australia?

1. Invertebrate assemblages of tropical freshwater rock pools (FRPs) are poorly known compared with temperate regions, where FRPs contain specialized, endemic taxa of high conservation value. Invertebrates were sampled from pristine FRPs in the Morgan River catchment in the Australian wet–dry tropics in the 2015 and 2016 wet seasons. Taxa were classified as either active or passive dispersers and by functional feeding groups. A range of physical variables were examined to identify associations with invertebrate assemblages.
2. Forty‐seven taxa were identified from FRPs; most were actively dispersing predatory insects, primarily Coleoptera and Hemiptera. Five adult insect species were found in most pools; other taxa were rare and scattered across FRPs. Two previously undescribed species of Spinicaudata were collected, but few crustacean taxa were recorded, and passively dispersing taxa were rare. Species accumulation curves indicated that had more pools been sampled, more taxa would have been collected in 2015, but in 2016 most species were collected.
3. There was no pattern in FRP assemblages related to any physical variable, but the assemblages in pools were correlated between sampling times. An opportunistic and mobile assemblage composed mostly of actively dispersing predatory insects may explain the absence of relationships with measured variables. Low hydrological stability in the wet–dry tropics may be associated with low taxon richness.
4. The dominance of actively dispersing insects is in contrast with FRP assemblages in temperate and arid regions. Studies of a wider range of FRPs from tropical regions are required to determine whether the fauna of these Kimberley FRPs are typical, and to fully describe short‐range endemic species across the Kimberley and elsewhere.
5. The FRPs have conservation value as habitat for endemic, specialist rock‐pool taxa, contributing to regional species pools. At present, a lack of knowledge of endemic FRP specialist species in tropical regions, including the Kimberley, impedes our ability to protect and conserve these species from disturbance.

     

Response of Scotian Shelf silver hake (Merluccius bilinearis) to environmental variability

Commercially‐exploited fish populations are not only shaped by fishing pressure, but also by the dynamics of their environment. By quantifying the influence of environmental variability, fisheries management advice can be improved and uncertainties reduced. To this end, we developed statistical models of the response of Scotian Shelf silver hake stock metrics to variability in zooplankton community composition and phenology over the past 18 years and in the physical environment since 1985. Dominant modes of variability in these pelagic habitat indicators were characterized using principal component analysis, and the relationships of silver hake condition, abundance, and recruitment to pelagic habitat variability were assessed using generalized additive models. Condition was largely modulated by the onset and duration of the spring bloom, which controls food availability. In contrast, adult abundance was governed by composition of the zooplankton community and bottom‐water temperature, which dictates the distribution of silver hake. Finally, recruitment was affected by both thermal conditions and food availability. Our results presented here form the basis for qualitative assessment of ecosystem attributes and the influence on silver hake stock productivity.     

Energy dynamics of subyearling Chinook salmon reveal the importance of piscivory to short‐term growth during early marine residence

Variation in prey quantity and quality can influence growth and survival of marine predators, including anadromous fish that migrate from freshwater systems. The objective of this study was to examine the energy dynamics of subyearling Chinook salmon (Oncorhynchus tshawytscha) following freshwater emigration. To address this objective, a population of Chinook salmon and their marine prey were repeatedly sampled from June to September over 2 years in coastal waters off Oregon and Washington. Subyearlings from the same population were also reared under laboratory conditions. Using a bioenergetics model evaluated in the laboratory, we found that growth rate variability in the field was associated more with differences in northern anchovy (Engraulis mordax) consumption and less with variation in diet energy density or ocean temperature. Highest growth rates (2.43–3.22% body weight/day) occurred in months when anchovy biomass peaked, and the timing of peak anchovy biomass varied by year. Our results support a general pattern among subyearling Chinook salmon occurring from Alaska to California that feeding rates contribute most to growth rate variability during early marine residence, although dominant prey types can differ seasonally, annually, or by ecosystem. In the northern California Current, faster growth appears to be associated with the availability of age‐0 anchovy. Identifying factors that influence the seasonal development of the prey field and regulate prey quantity and quality will improve understanding of salmon growth and survival during early marine residence.     

The loss of large wood affects rocky mountain trout populations

Western U.S. rivers are currently influenced by legacy effects of reduced large wood (LW) loading and retention that has substantially reduced in‐stream habitat complexity. Large wood is typically associated with streams in undisturbed old‐growth forest and in the correct geomorphic context can drastically alter stream and valley habitat complexity. Streams with LW are typically multichannel and depositional, while streams lacking LW, due to relatively recent wildfire or logging (<200 years ago), are usually single channelled and erosional. We compared population biomass and individual growth rates of Brook Trout Salvelinus fontinalis in streams across a gradient of wood volumes. At both the square metre and valley length scales, standing stock biomass of aquatic invertebrates was the best predictor of trout biomass. However, at the valley scale, the number of pools was important in predicting trout biomass in combination with standing stock biomass of aquatic invertebrates. Individual growth rates of age‐1 Brook Trout were negatively affected by increasing density; however, growth rates for the largest and smallest individuals at each site were unaffected by density. Our results suggest the pool habitat created by LW acts synergistically with prey availability to dramatically increase trout populations. However, in streams lacking LW, negative effects of detrimental land use practices have persisted >100 years, suggesting that recovering lost animal production in mountain stream networks will only occur at decadal to century time scales.