59 research outputs found
The leucogram as an indicator of marine-cultured rainbow trout, Oncorhynchus mykiss (Walbaum), health in the Netherlands
No full textDuring a longitudinal survey from June until October 1987 cytological blood parameters of smoltified marine cultured rainbow trout, Oncorhynchus mykiss (Walbaum), were monitored. In this period, the trout were exposed to environmental stress resulting in summer mortality. The statistical analyses showed that the observed summer mortality was preceeded by a shift in the relative abundance of different peripheral white blood cells (PWBCs), from lymphocytic to extremely granulocytic, which was mainly attributed to mature granulocytes. It was concluded that changes in relative abundance of PWBCs can predict health disturbances in marine-cultured rainbow trout.TR: CS9719570Source type: Electronic(1
Parasites and hepatic lesions among pink salmon, Oncorhynchus gorbuscha (Walbaum), during early seawater residence
No full textJuvenile pink salmon, Oncorhynchus gorbuscha (Walbaum), in the Broughton Archipelago region of western Canada were surveyed over 2 years for sea lice (Lepeophtheirus salmonis and Caligus clemensi), gross and microscopic lesions and evidence of infections with viruses and bacteria. The 1071 fish examined had an approximate ocean residence time no longer than 3 months. A high prevalence of degenerative liver lesions, renal myxosporean parasites and a low prevalence of skin lesions and sea lice were observed. No indications of viral or bacterial diseases were detected in either year. The monthly prevalence of sea lice in 2007 (18-51%) was higher than in 2008 (1-26%), and the infestation density exceeded the lethal threshold in only two fish. Degenerative hepatic lesions and renal myxosporean parasites occurred in approximately 40% of the pink salmon examined in June of both years, and the peak monthly prevalence of hepatocellular hydropic degeneration was greater in 2007 (32%, in May) than in 2008 (12%, in June). Logistic regression analysis found skin lesions and hepatocellular hydropic degeneration significantly associated with sea lice. Most parasites and lesions occurred during both years, but the prevalence was often higher in 2007. Fish weight was 35% less in June 2007 than in June 2008, but condition factor was not different. Further research is required to monitor inter-annual variations and aetiology of the liver lesions and to assess their potential role on pink salmon survival.Source type: Electronic(1
(Walbaum in Artedi, 1792))
No full textThe consumption of invasive, high-thiaminase prey fishes can cause thiamine deficiency, which has been hypothesized to be a major barrier for lake trout (Salvelinus namaycush Walbaum in Artedi, 1792) restoration in the Great Lakes. In fishes, an understudied aspect of thiamine deficiency is its effect on cardiac function, despite evidence of this effect in mammals. Here, parr of two strains of lake trout (Seneca and Slate) were raised on either a control or high-thiaminase diet for nine months. We then measured cardiac function and morphology, particularly as it relates to the ability of the heart to meet oxygen demands at warmer water temperatures. The thiaminase diet was associated with significant heart enlargement and reduced cardiac performance at high temperatures. These effects were observed in both strains, but were more pronounced in Slate strain fish. Our data suggest that dietary thiaminase impairs cardiac function in fishes, and that these impairments may become increasingly important as water temperatures increase through climate change.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Design guidelines for circular building components based on LCA and MFA: The case of the circular kitchen
No full textIntroduction. The building sector consumes 40% of resources globally, produces 40% of global waste and 33% of all emissions. The transition towards a Circular Economy (CE) in the built environment is vital to achieve Sustainable Development Goals (SDGs) such as responsible consumption and production. The built environment can gradually be made circular by replacing the current 'linear' building components with circular ones during maintenance and renovation. However, there are many possible design alternatives for circular building components; knowledge on which variants perform best - from an environmental perspective - is lacking. Methods. In this article, we develop environmental design guidelines for circular building components. First, we synthesize design variants for an exemplary circular building component: the Circular Kitchen (CIK). Second, we compare the environmental performance of these variants and a 'business-as-usual' variant by applying a Material Flow Analysis (MFA) and Life Cycle Assessment (LCA). Finally, from the results, we derive design guidelines. Results. We synthesized four design variants: (1) a kitchen made from bio-based, biodegradable materials, (2) a kitchen made from re-used materials, (3) a kitchen which optimises lifespans and materials, and (4) a modular kitchen in which components (with varying lifespans) are re-used by the manufacturer. From the LCA and MFA, we derived 7 design guidelines, which include: consider building components as a composite of sub-components, parts and materials with different and multiple use-, and life-cycles; match the materialisation of each part with the expected life cycle (merely substituting for re-used or low-impact materials does not provide the most circular design); facilitate various loops (e.g., repair, re-use, recycling) simultaneously. Conclusions. The presented design guidelines can support industry in developing circular building components and, through implementation of these components, support the creation of a circular built environment.Housing ManagementBuilding Energy Epidemiolog
Genetically modified growth affects allometry of eye and brain in salmonids
No full textEffects of growth acceleration on eye development have been examined in genetically modified salmonids. Growth hormone (GH) transgenic coho salmon (Oncorhynchus kisutch (Walbaum, 1792)) show dramatically elevated overall body growth and an absolute increase in eye size, but relative eye growth is shifted from negatively allometric to more isometric. Thus, transgenic fish possess significantly smaller eyes relative to nontransgenic fish of the same size. Ration-restricted limitation of growth in transgenic salmon to that of wild type restores relative eye growth rate, suggesting that effects on eyes are an indirect consequence of modification of growth rate rather than a direct effect of GH overexpression. Heart, spleen, and liver did not show changes in proportion among groups, whereas total brain size showed the same response as eye. Relative eye and brain size were also reduced in a fast-growing domesticated strain of rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)), suggesting modifications of allometry are a more general effect of growth acceleration. GH mRNA levels from the transgene were elevated in eyes, whereas IGF-I mRNA was not, suggesting this organ may be regulated in a different fashion than other organs. Neural tissues with critical structural requirements for optimal function may be subject to less modification of growth rate than are other organ systems.Source type: Electronic(1
Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.
No full textA Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon
Clupeidae
No full textClupeidae * Sardina pilchardus (Walbaum, 1792)—European pilchard Sardinella aurita Valenciennes, 1847 —Round sardinella No specimens in the MMF collection but there is a specimen in SMNS 25227 (1) and the first author has photographed the species at Madeira. * Sardinella maderensis (Lowe, 1838)—Madeira sardinellaPublished as part of Wirtz, Peter, Fricke, Ronald & Biscoito, Manuel José, 2008, The coastal fishes of Madeira Island — new records and an annotated check-list, pp. 1-26 in Zootaxa 1715 on page 7, DOI: 10.5281/zenodo.27412
Salmon juveniles are vulnerable to predation by invasive African clawed frogs in Washington state
No full textThe Pacific Northwest, U.S.A. hosts multiple threatened salmonid species. Predation by introduced species are among the threats salmon face. African clawed frogs (ACF; Xenopus laevis,(Daudin, 1802) ) are a generalist, non-native invasive species recently found in waterways in Washington State, USA. Our goal was to identify if ACF posed a threat to early life stages of Chinook (Oncorhynchus tshawytscha, (Walbaum in Artedi, 1792)), coho (Oncorhynchus kisutch,(Walbaum, 1792)), and chum (Oncorhynchus keta,(Walbaum in Artedi, 1792)) salmon. We conducted feeding trials to discover the foraging propensity of ACF on salmon in three development phases, eyed eggs, alevin, and fry. We predicted that ACF would most readily consume less mobile life stages, based on foraging in other amphibians. Our results showed that ACF consumed all species at all juvenile life stages. The life stage experiencing the highest rates of consumption was salmon fry (72% consumption) and the lowest was eyed eggs (24% consumption). Gravel shelter minimally buffered ACF consumption. Given the growing presence of ACF in proximity to salmon spawning waterways, ACF may pose an additional threat to salmonid recruitment, and require further study to investigate potential interactions.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Trophic ecology of nonanadromous rainbow trout in a post-glacial lake system: partial convergence of adfluvial and fluvial forms
No full textThe rainbow trout (Oncorhynchus mykiss Walbaum, 1792) is one of many salmonid species exhibiting a gradient of life histories including fluvial (stream-resident), anadromous (ocean-migrant), and adfluvial (lake-migrant) forms, the last of which is less extensively studied than the other two. Our goal was to determine the extent of diet segregation between fluvial and adfluvial rainbow trout. We collected stomach content and stable isotope data on rainbow trout sampled in stream and lake habitats in a southwestern Alaska watershed during summer, and compared them to data on sympatric stream- and lake-specialist char species (Salvelinus malma Walbaum, 1792 and S. alpinus Linnaeus, 1758, respectively). Rainbow trout in streams fed largely on aquatic insects while those in the lake ate primarily benthic snails and amphipods. The trophic segregation of stream-resident and lake-migrant rainbow trout mirrored but was less extreme than the divergence of lotic Dolly Varden (S. malma) and lentic Arctic char (S. alpinus) in the same system. Spawning sockeye salmon (Oncorhynchus nerka Walbaum, 1792) provided a nutrient subsidy in the form of eggs that supported rainbow trout in both stream and lake (littoral) habitats, causing their isotopic signatures to converge. This study augments knowledge of partial migration and trophic divergence within populations.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Sunlight Modulates Fruit Metabolic Profile and Shapes the Spatial Pattern of Compound Accumulation within the Grape Cluster
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