Letteratura scientifica selezionata sul tema "Gudgeon"
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Articoli di riviste sul tema "Gudgeon"
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Ohee, Henderite L., Gerardinalia Ngamelubun, Joane J. Ansaka, Novela H. Korwa e Puguh Sujarta. "Ekologi dan Kelimpahan Ikan Sentani Gudgeon (Oxyeleotris heterodon, Weber 1908) dan Snakehead Gudgeon (Giuris margaritacea, Valenciennes 1837) di Danau Sentani, Papua". JURNAL BIOLOGI PAPUA 11, n. 1 (29 maggio 2019): 24–32. http://dx.doi.org/10.31957/jbp.646.
Testo completoAbstract (sommario):
Freshwater community in Lake Sentani comprise of 35 species including three endemic species, seven native species, eight anadromous fish and 17 introduced species. Two native species are Sentani Gudgeon (Oxyeleotris heterodon) and Snakehead Gudgeon (Giuris margaritacea). The survey aims to document the ecology and fish abundance of the gudgeons in Lake Sentani. Fish sampling was done passively by using gill nets with three different mesh sizes in five locations; Puai, Enandowai, Waena, Ayapo and Yahim. Substrate type, water vegetations, habitat depth and fish abundance were recorded each locations. Substrate preferences of the gudgeons are sand, mud and gravel, while O. heterodon was more abundance in sand mud substrate type. Moreover, water vegetation preference was different between O. heterodon and G. margaritacea. Sentani Gudgeon prefer habitat with dense water vegetations, while G. margaritaceus could be found in habitat with or without water vegetation. Theses two gudgeons were found in relatively the same habitat depth, up to 7 meters depth. O. heterodon and G. margaritacea had a very low abundance in the lake. It is important to conserve lake area from the edge up to 7 meter depth that consist of sand, mud and gravel substrate types and dense water vegetation to ensure the population of these two gudgeons are abundance in Lake Sentani. Key words: Ecology, Lake Sentani, relative abundance, O. heterodon, G. margaritacea.
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Boxall, George D., John J. Sandberg e Frederieke J. Kroon. "Population structure, movement and habitat preferences of the purple-spotted gudgeon, Mogurnda adspersa". Marine and Freshwater Research 53, n. 5 (2002): 909. http://dx.doi.org/10.1071/mf01039.
Testo completoAbstract (sommario):
We examined the movement patterns and habitat preferences of Mogurnda adspersa in Pattersons Creek, a small, low-order, rainforest creek in Gillies Range State Forest, Far North Queensland, Australia. First, we conducted a capture and recapture study to document population structure and individual movements. Our results show that movement is a prominent feature of population behaviour of M. adspersa, with male gudgeons moving significantly more between pools than females, irrespective of gudgeon size. Second, we quantitatively described habitat characteristics of rainforest pools using point sampling. This data was then combined with capture data to describe the habitat preference of M. adspersa. Our results show that the number of gudgeons was positively related to pool size and decreased with increasing pool velocity. We discuss the results in light of effective management options for the species habitat in general, and Far North Queensland in particular.
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Arsovska, Julijana, Milica Ristovska, Predrag Simonović, Vasil Kostov e Valentina Slavevska-Stamenkovič. "First data on the structure of the vertebral column in Gobio and Romanogobio species (Actinopterygii, Cypriniformes, Gobionidae) from Ohrid Lake and the Vardar River basin". Acta Ichthyologica et Piscatoria 51, n. 1 (31 marzo 2021): 37–45. http://dx.doi.org/10.3897/aiep.51.63489.
Testo completoAbstract (sommario):
The validity of four gudgeon species known for the ichthyofauna of North Macedonia has been a matter of different taxonomic disputes (except for Gobio ohridanus Karaman, 1924). Recently, a restoration of the species status was proposed for Gobio balcanicus Dimovski et Grupče, 1977 and Romanogobio banarescui (Dimovski et Grupče, 1974). So far, Romanogobio stankoi (Karaman, 1974), has not been a part of any recent investigation and it is still considered as a junior synonym of Romanogobio elimeius (Kattoulas, Stephanidis et Economidis, 1973) or R. banarescui due to the lack of distinctive morphological characters. The osteological characters in the structure of the vertebral column, have significance to the systematics of the gudgeons, especially in elevation of Romanogobio at the level of genus. To contribute to resolving the taxonomic status in these gudgeon species, the goal of this paper is to identify distinctive characters by presenting and analyzing the structure of their vertebral column. Samples were inspected from the fish collections in the Institute of Biology (G. ohridanus), the Institute of Animal Science (G. balcanicus), and the Macedonian Museum of Natural History (both Romanogobio species). Fish samples were X-rayed as well as cleared and double-stained. Obtained data on the number of vertebrae were presented through the vertebral formula following Naseka (1996). Multiple Correspondence Analysis (MCA) was used to check the interrelation between taxa and the number of vertebrae in all units of the vertebral column. G. balcanicus is distinguished from G. ohridanus mainly in the predorsal and preanal subregion (10 vs. 11 vertebrae and 1 vs. 0 vertebrae, respectively), while R. stankoi distinguishes from R. banarescui by the number of vertebrae in the preanal and postanal subregion (2 vs. 4 vertebrae and 19 vs. 17 vertebrae, respectively). The structure of vertebral column offers distinctive morphological characters for the four gudgeon species from Ohird Lake and the Vardar River basin.
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Bertozzi, Terry, Mark Adams e Keith F. Walker. "Species boundaries in carp gudgeons (Eleotrididae : Hypseleotris) from the River Murray, South Australia: evidence for multiple species and extensive hybridization". Marine and Freshwater Research 51, n. 8 (2000): 805. http://dx.doi.org/10.1071/mf00039.
Testo completoAbstract (sommario):
Allozyme analyses of carp gudgeons (Hypseleotris) from five sites in the lower River Murray revealed three distinctive taxa designated HA, HB and HC, diagnosable from one another by fixed differences at 3–5 loci, and three apparent F 1 hybrid forms, HA¥HB, HA¥HX and HB¥HX, where HX denotes a taxon not sampled in its ‘pure’ form. Of all fish sampled, 25% were hybrids, although only one hybrid form was found at any one site, and never in company with both parental taxa. No hybrids involving HC were found, although this was the most common taxon, and no HA¥HB hybrids were present at the one site of demonstrated sympatry between the parental taxa. Morphological analysis and the lack of introgression confirm that HA, HB, and HC are distinct biological species. Partial meristic data suggest that HC corresponds to H. klunzingeri s.l., ‘Midgley’s carp gudgeon’ is a composite of HA, HB and HA¥HB hybrids, and ‘Lake’s carp gudgeon’ may be a composite of HX and one of its hybrids (HB¥HX). We speculate that one or more of the hybrid classes may be ‘unisexual lineages’ (clonally reproducing, usually all-female forms derived from hybridization between congeners).
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Schmidt, Daniel J., Joel A. Huey, Nick R. Bond e Jane M. Hughes. "Population structure of sexually reproducing carp gudgeons: does a metapopulation offer refuge from sexual parasitism?" Marine and Freshwater Research 64, n. 3 (2013): 223. http://dx.doi.org/10.1071/mf12305.
Testo completoAbstract (sommario):
Australian carp gudgeons (Hypseleotris spp.) of the Murray–Darling basin are a species complex including sexually reproducing taxa and unisexual hybrid lineages that reproduce via hybridogenesis. Unisexual fish require gametes of a sexual species to propagate themselves and can be regarded as ‘sexual parasites’ capable of driving closed populations to extinction. Metapopulation dynamics have been proposed as a mechanism that could facilitate coexistence between a sexual parasite and its ‘host’. This study evaluates whether patterns of spatial genetic variation are compatible with metapopulation dynamics for a sexually reproducing member of the carp gudgeon complex (Hypseleotris sp. HA), in the Granite Creeks system of central Victoria. Genetic differentiation of fish among all study sites was accommodated by a model of migration-drift equilibrium using decomposed pairwise regression analysis. Given that the population was divided into discrete patches in the form of refugial waterholes during the time of this study, we infer that spatially constrained source–sink metapopulation dynamics may be responsible for producing this pattern. It is therefore possible that metapopulation dynamics contribute to coexistence in the Granite Creeks carp gudgeon hybridogenetic system, and further analysis is required to determine the relative importance of environmental versus demographic factors towards patch extinction.
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Wiegleb, Joschka, Philipp E. Hirsch, Frank Seidel, Georg Rauter e Patricia Burkhardt-Holm. "Flow, force, behaviour: assessment of a prototype hydraulic barrier for invasive fish". Hydrobiologia 849, n. 4 (3 dicembre 2021): 1001–19. http://dx.doi.org/10.1007/s10750-021-04762-z.
Testo completoAbstract (sommario):
AbstractMigration barriers being selective for invasive species could protect pristine upstream areas. We designed and tested a prototype protective barrier in a vertical slot fish pass. Based on the individuals’ swimming responses to the barrier flow field, we assumed this barrier would block the ascension of the invasive round goby, but allow comparable native species (gudgeon and bullhead) to ascend. The barrier was tested in three steps: flow description, quantification of forces experienced by preserved fish in the flow field, and tracking the swimming trajectories of ca. 43 live fish per trial and species. The flow and the forces were homogenous over the barrier, though gudgeon experienced significantly smaller forces than round goby or bullhead. The swimming trajectories were distinct enough to predict the fish species with a random forest machine learning approach (92.16% accuracy for gudgeon and 85.24% for round goby). The trajectories revealed round goby and gudgeon exhibited increased, but varied, swimming speeds and straighter paths at higher water discharge. These results suggest that passage of round goby was prevented at 130 L/s water discharge, whereas gudgeon and bullhead could pass the barrier. Our findings open a new avenue of research on hydraulic constructions for species conservation.
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ABINAWANTO, ABINAWANTO, e EKA DEWI SRIYANI. "Characterization of Sentani gudgeon, Oxyeleotris heterodon (Weber, 1907) at Sentani Lake, Papua, Indonesia based on truss morphometric". Biodiversitas Journal of Biological Diversity 19, n. 3 (1 maggio 2018): 1013–20. http://dx.doi.org/10.13057/biodiv/d190333.
Testo completoAbstract (sommario):
Abinawanto, Sriyani ED, Bowolaksono A. 2018. Characterization of Sentani gudgeon, Oxyeleotris heterodon (Weber, 1907) at Sentani Lake, Papua, Indonesia based on truss morphometric. Biodiversitas 19: 1013-1020. The study concerning the morphometry of Sentani gudgeon (Oxyeleotris heterodon, Weber 1907) was done from August 2016 until April 2017 in Sentani Lake, Jayapura District, Papua Province, Indonesia. The objectives of the study were to find out the diversity of the fish using truss morphometry approach. A total 56 individual sampled from three sampling sites were characterized for their 26 truss morphometric characters. The result showed that there were differences on morphometric characters of Sentani gudgeon. The highest correlation value found in character B2 and D5, which represented the dorsal portion and the tail fin of the fish body respectively. All variables showed significant different between each location (the p-value <c0.05). The canonical diagram resulted of 26 truss morphometric characters illustrated three separated clusters which discriminated the three populations based on sampling sites. A genetic distance analysis among Sentani gudgeon indicated that the fish originated from Putali Village was morphologically closed to the fish population from Sosiri. The truss morphometry technique can be used to identify the diversity of Sentani gudgeon in Sentani Lake
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Taylor, M. J., e D. Hoole. "Ligula intestinalis (L.) (Cestoda: Pseudophyllidea): polarization of cyprinid leucocytes as an indicator of host-and parasite-derived chemoattractants". Parasitology 107, n. 4 (novembre 1993): 433–40. http://dx.doi.org/10.1017/s0031182000067792.
Testo completoAbstract (sommario):
SUMMARYFreshly isolated pronephric leucocytes from roach, Rutilus rutilus and gudgeon, Gobio gobio were exposed to extracts of plerocercoids of Ligula intestinalis from these two cyprinid fish. Addition of the extracts or an increase in incubation temperature from 10 to 20 °C induced polarization of neutrophils and L1 granulocytes. Cells were transformed from their typical spherical shape to elongate forms possessing a ruffled leading edge. Extracts obtained from gudgeon-Ligula stimulated polarization of both roach and gudgeon leucocytes at 10 and 20 °C. In contrast, extracts from roach-Ligula, whilst having little effect at 10 °C, suppressed temperature-induced polarization of leucocytes at 20 °C. Addition of serum to all the essays enhanced polarization and abolished the roach-Ligula-induced suppression. It is suggested that leucocyte chemoattractants are present in Ligula from roach and gudgeon and only parasites from the former host contain an inhibitor of polarization. In addition, host-derived factors possibly complement, may be involved in leucocyte chemoattraction.
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Pospichal, A., D. Pokorova, T. Vesely e V. Piackova. "Susceptibility of the topmouth gudgeon (Pseudorasbora parva) to CyHV-3 under no-stress and stress conditions". Veterinární Medicína 63, No. 5 (29 maggio 2018): 229–39. http://dx.doi.org/10.17221/88/2017-vetmed.
Testo completoAbstract (sommario):
Cyprinid herpesvirus 3 (CyHV-3), also known as koi herpesvirus, is the causative agent of the highly contagious koi herpesvirus disease, which is restricted to koi and common carp and causes significant losses in both fish stock. Some experimental investigations have shown that other cyprinid or non-cyprinid species may be asymptomatically susceptible to this virus and might play roles as potential carriers of CyHV-3 or might contribute to persistence of this virus in environment. Therefore, it seems important to verify not only the susceptibility of other cyprinid or non-cyprinid species, but also their ability to transmit CyHV-3 infection to susceptible species. Our previous investigation of the susceptibility of the topmouth gudgeon (Pseudorasbora parva) did not reveal the presence of CyHV-3 DNA in the tissues of this species after cohabitation with infected koi. Consequently, we changed the experimental conditions and applied two stress factors (removal of skin mucus and scaring) which would presumably mimic the stress most commonly encountered in the wild. Both experiments (without and with stress factors) consisted of primary and secondary challenges. In both the no-stress and stress experiments, the first challenge was focused only on testing the susceptibility of the topmouth gudgeon to the virus. With the secondary challenge, we investigated potential viral transmission from the topmouth gudgeon to healthy naive koi after exposure to stress factors. All fish (dead, surviving and sacrificed) were tested for the presence of CyHV-3 DNA using nested PCR (no-stress experiment) and real-time PCR (stress experiment). After the primary challenge of the no-stress experiment, PCR did not reveal the presence of CyHV-3 DNA in any specimen of cohabitated topmouth gudgeon, but all specimens of dead koi were CyHV-3 DNA-positive. PCR of fish tissues subjected to the secondary challenge did not show the transfer of virus to naive fish. After exposure to stress (removal of skin mucus), qPCR revealed four out of five samples (80%) of topmouth gudgeon to be positive for CyHV-3 DNA. Two out of five samples (40%) of topmouth gudgeon treated by scaring were found to be positive for the presence of viral DNA. Real-time PCR after the secondary challenge did not reveal any viral DNA positivity in specimens of topmouth gudgeon from groups previously exposed to stress. The stress experiments show that removal of skin mucus might potentially lead to susceptibility of topmouth gudgeon to CyHV-3 infection, but the transmission of the virus to koi carp was not observed.
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Záhorská, Eva, Vladimír Kováč, Kristína Švolíková e Andrzej Kapusta. "Reproductive parameters of topmouth gudgeon (Pseudorasbora parva) from a heated Lake Licheńskie (Poland)". Open Life Sciences 9, n. 2 (1 febbraio 2014): 212–19. http://dx.doi.org/10.2478/s11535-013-0252-3.
Testo completoAbstract (sommario):
AbstractTemperature regime is known to have considerable influence on the life-histories of fish. Topmouth gudgeon is a very successful invader with high biological flexibility and phenotypic plasticity. The flexibility of topmouth gudgeon in a normal thermal regime has been well described, however there has been no information published about how it would cope with extreme conditions, e.g. permanently heated water. Several studies have demonstrated that phenotypic plasticity provides an important advantage to invasive species. To explain their invasion success, the theory of alternative ontogenies and invasive potential has been proposed. The aim of the present study was to examine if the reproductive parameters of a population living in permanently heated water differ from those living in habitats with a normal temperature regime, as well as to test a hypothesis derived from the theory of alternative ontogenies and invasive potential. Over a period of 8 years (2004–2011), a high variation in the reproductive parameters of topmouth gudgeon from Lake Licheńskie was found. With a small exception, all the observed results met the expectations predicted by the hypothesis tested. This indicates that topmouth gudgeon retains high phenotypic plasticity in life-history traits even in a habitat with extreme conditions, which is important for the species’ invasion success.
Tesi sul tema "Gudgeon"
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Davies, Gareth Dyfrig. "Applied ecology and management of the invasive topmouth gudgeon Pseudorabora parva in England & Wales". Thesis, Bournemouth University, 2015. http://eprints.bournemouth.ac.uk/24526/.
Testo completoAbstract (sommario):
Introduced species are a major threat to native biodiversity and, whilst there are socio-economic benefits often gained from introductions, there are also inherent risks to receiving ecosystems, particularly from those species that develop invasions. This is problematic, as once in the wild, their management is inherently difficult. The most effective method to avoid an invasion is preventing the initial introduction; if this is unsuccessful, then methods should aim to minimise the dispersal opportunities of the species into the wider environment. This research used the Asian fish of the Cyprinidae family, topmouth gudgeon Pseudorasbora parva, as the model species, a highly invasive fish in mainland Europe. England and Wales was the model area, where 26 P. parva populations have been recorded but the species is not yet invasive. The research identified how aspects of P. parva ecology can underpin the application of methods to prevent their wider dispersal into the environment to prevent their invasion. It covered work on: (i) the expression of their life history traits; (ii) preventing their introduction into inland waters via fish movement audits; (iii) identifying the risk of their dispersal into river catchments from aquaculture sites; and (iv) assessing how their populations can be controlled to minimise dispersal opportunities. Assessments of their somatic growth rates in relation to temperature and latitude revealed that whilst temperature was a strong regulator of growth in controlled conditions, in the wild, population density was important, with this having a stronger influence on growth rates than latitude (temperature). Individuals in recently founded populations and at low densities had very fast growth rates, with this advantageous in facilitating their establishment, with these growth rates slowing as population abundance increased. Assessments of their reproductive traits revealed that, contrary to European and Asian populations, they did not show an extended reproductive period involving fractional spawning, but instead had a discrete reproductive season that lasted no longer than three weeks in the early summer period. Approximately 8000 fish movements (i.e. removals from fisheries, stocking into fisheries) are legally consented by the Environment Agency in England each year. On each of these stockings, there is a concomitant risk of also accidentally introducing a ‘hitch-hiking’ species that has not been detected in the batch of fish. To test whether a ‘fish movement audit’ scheme could reduce this risk, an experiment was completed on batches of native fish containing known proportions of P. parva and using auditors of varying non-native fish knowledge and pre-defined searching effort levels. Outputs revealed that although the scheme could be successful at preventing 95 % of accidental introductions, this required highly experienced auditors using high searching efforts. The presence of P. parva on an aquaculture site in Southern England enabled completion of field studies on assessing their drifting rates from the farm and into an adjacent stream. Drift rates were negligible during normal summer operations. However, when aquaculture ponds on the site were drained down for husbandry purposes, the elevated flow of water displaced high numbers of mature P. parva, resulting in high dispersal rates. Whilst no P. parva were recorded in the three hours prior to ponds being drained down, over 200 were captured in drift nets in the 21 hours after draining commenced. Thus, whilst the overall risk of their dispersal was low, this was elevated considerably during specific on-site activities, and would require pro-active management to prevent accidental dispersal during these activities. A long-term field experiment, allied with a field study, revealed that in small fishing and aquaculture ponds, P. parva population densities can be maintained at very low abundances over long time periods, but required a combination of biocontrol (via manipulating of numbers of native piscivorous fish) and targeted fish removals (by trapping in spring and autumn). Fish removals alone were unable to reduce population sizes due to the compensatory responses of the remaining fish. These responses were not, however, detected when native piscivorous fish were present, probably through their predation of nest-guarding male P. parva that then inhibited large numbers of in young-of-the-year being produced. In summary, the research revealed utility of non-native fish management methods being applied to populations following their testing in more controlled conditions. It revealed that introductions into fisheries of fast growing, small-bodied, non-native fishes can be prevented by auditing, and where this is unsuccessful then their dispersal into the wider environment can be minimised, if not eliminated, by a variety of method that should reduce their invasion risk.
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Syaifullah, of Western Sydney Hawkesbury University e Faculty of Science and Technology. "Genetic variation and population structure within the Gudgeon genus Hypseleotris (Pisces-Eleotridae) in Southeastern Australia". THESIS_FST_XXX_Syaifullah_X.xml, 1999. http://handle.uws.edu.au:8081/1959.7/231.
Testo completoAbstract (sommario):
This study investigated the causes of high level of intra-and inter-population variation known to occur in the morphology of fish in the genus Hypseleotris Eleotride in southern Australia, particularly within the Murray-Darling river system. The three major objectives of the study were, identify the number and distribution of species,determine the genetic structure of the populations and analyse relationships between species and consider the process of speciation in this species complex. The investigation of morphological variation in Hypseleotris confirmed the presence of two well known species i.e. H. compressa and H. galli, in the coastal rivers and also of the inland species H. klunzingeri. Populations of Hypseleotris klunzigeri sensu lato in inland river were found to be very highly variable and analysis using discriminant functions and principle component analysis showed the widespread presence of three forms (A, B1 and B2). The analysis was confused by the presence of north/south clines and upstream/downstream variation in characteristic in each form. After these factors were removed, there was still a great deal of variation in each population. The presence of hybrids between each pair of inland species, identified by both morphological and genetic data, further confused the analysis and makes identification of all specimens to species in the field difficult. Examination of type material of H. Klunzingeri showed that this belonged to form B2. The other forms can be related to the undescribed species, Midgley's carp gudgeon and Lake's carp gudgeon. Keys to the species in the complex in southeastern Australia are given. The morphological and genetic data show that H. compressa and H. klunzingeri are sister species, primarily separated by the eastern uplands. Similarly, the coastal species, H. galli is related to form B1 and more distantly, to form A. Possible scenarios for the complex are given.Doctor of Philosophy (PhD)
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Syaifullah. "Genetic variation and population structure within the Gudgeon genus Hypseleotris (Pisces-Eleotridae) in Southeastern Australia /". View thesis View thesis, 2000. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030508.154626/index.html.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--University of Western Sydney, Hawkesbury, 1999."A Thesis submitted to the Faculty of Science and Technology in fulfilment of the requirements for the Degree of Doctor of Philosophy". "November 1999". Bibliography : leaves 147-155.
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Taylor, Mark. "Immunoparasitological studies on Ligula intestinalis (Cestoda: Pseudophyllidea) in roach (Rutilus rutilus) and gudgeon (Gobio gobio)". Thesis, Keele University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304479.
Testo completo
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Fletcher, David. "Biological invasion risk assessment, considering adaptation at multiple scales : the case of topmouth gudgeon Pseudorasbora parva". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG029/document.
Testo completoAbstract (sommario):
Afin de quantifier les risques d’invasion chez le goujon Asiatique Pseudorasbora parva, un petit cyprinidae d’eau douce, j’ai tout d’abord testé une approche corrélative de modélisation de la niche climatique dans laquelle j’ai intégré un proxy relatif à la probabilité d’introduction. Cette approche s’appuie sur des assomptions relatives à l’adaptation des organismes aux conditions environnementales locales ou régionales. J’ai ensuite comparé la niche climatique mesurée de deux lignées génétiques majeures à la fois dans les aires natives et envahies. Puis dans un second temps, par une approche expérimentale j’ai comparé la réponse aux variations de température, des traits d’histoire de vie de populations vivant dans des zones climatiques contrastées. Finalement, je me suis intéressé à la dispersion des goujons Asiatiques afin de mieux comprendre si les populations situées sur les fronts d’invasions avaient des capacités de colonisation plus importante. J’ai donc quantifié et comparé le long d’un gradient d’invasion, le potentiel de dispersion des individus ainsi que des traits pouvant y être liés (activité et morphologie). L’étude des risques d’invasions a montré que de nombreuses zones – au delà des zones déjà envahies - étaient climatiquement favorables au goujon Asiatique. C’était le cas en particulier pour certaines zones comme l’Australie, l’Amérique du Sud et du Nord, indiquant que l’invasion de cette espèce pourrait encore s’étendre. Après avoir pris en compte les probabilités d’introduction, cette étude a montré que l’Amérique du Nord était la zone la plus à risques. Par contre, la niche climatique entre les différentes lignées dans les zones géographiques envahies est très similaire, ce qui laisse à penser qu’il n’y a pas de patrons d’adaptation locale chez cette espèce. Pour autant, la niche climatique observée dans la zone envahie est très différente de celle observée dans la zone native, ce qui suggère un shift climatique important au cours de l’invasion. Les réponses thermiques des traits d’histoire de vie du goujon Asiatique testés expérimentalement n’ont pas varié significativement entre les populations originaires de conditions climatiques continentales et maritime-tempérées. Par exemple, l’effort reproductif global des femelles n’a pas varié entre les températures testées (15-25°C) mais la stratégie temporelle de reproduction a beaucoup varié. L’effort reproductif était plus cours et plus intense à forte température, alors qu’il était plus étalé et avec des pics reproductifs moins forts à faible température. Pour ailleurs, il semble qu’il existe un gradient morphologique fort entre les populations situées à différentes distances du front d’invasion ce qui suggère une forte plasticité morphologique mais qui ne serait pas liée à la capacité de dispersion de ces populations. En effet, cette dernière ne variant pas significativement le long du gradient d’invasion. La capacité de dispersion serait principalement liée à la taille du corps de goujon Asiatique, les individus les plus grands ayant une probabilité plus élevée de disperser.Bien que les prédictions générales du modèle de niche puissent être affectées par de potentielles adaptations à l’échelle de la population ou de la lignée évolutive, les résultats suggèrent qu’une certaine incertitude liée à ces prédictions persiste puisque la distribution native ne prédisait que très mal la distribution actuelle dans les zones envahies. Par ailleurs, mes travaux expérimentaux à plus fine échelle suggèrent que cette espèce est extrêmement adaptable et tolère une large gamme environnementale, ce qui pourrait expliquer son caractère invasif. Les connaissances produites au cours de cette thèse constituent donc des ressources extrêmement pertinentes pour développer des stratégies de gestion visant à contrôler les invasions futures du goujon AsiatiqueIn this thesis I set out to quantify the risk of invasion from the invasive freshwater fish, Pseudorasbora parva, at a global extent, using traditional correlative ecological niche modelling approaches with the integration of surrogate data representing introduction likelihood (Chapter I). These correlative approaches rely upon key assumptions relating to the presence or absence of local or regional adaptations, and so I subsequently tested for evidence of such adaptations in genetic lineages and in individual populations. This was achieved through analyzing climatic niche differentiation of key genetic lineages in the native and invasive ranges (Chapter II) and by conducting lab experiments comparing thermal responses of important life history traits in populations from contrasting climates (Chapter III). The initial risk assessment did not account for a key factor in invasions; namely, natural dispersal. Natural dispersal has been observed to be subject to selection in vanguard populations of invasive species, and adaptation of dispersal traits can infer additional invasive vigor, allowing the species to spread across the landscape quicker. For this reason, I quantified dispersal, activity and morphological differences, often associated with differential dispersal ability, in populations along a distance-gradient from an invasion front, in order to identify if P. parva is capable of such adaptations.The initial risk mapping study showed that large areas, beyond the current distribution of the species, are climatically suitable. These areas are mainly in North and South America, Australia and New Zealand, and constitute significant scope for spread and impact of this species. When introduction likelihood was included, N. America appears most at risk. I found no evidence to suggest that native genetic lineages represented local adaptations to their respective native climates - there was little or no differentiation of the lineages’ climatic niches in the invasive range. It was also apparent, from the niche comparisons, that the climatic niche in the invaded range constituted a significant shift, compared to the native range. The thermal responses of P. parva life history traits did not differ significantly between populations from a strongly seasonal continental climate and a mild temperate maritime climate. The overall reproductive output of females did not vary according to breeding season temperature, however, temporal reproductive strategy showed a strong response, with lower temperatures inducing a protracted breeding season and higher temperatures inducing rapid and intense reproductive output. The dispersal and morphology-related study identified a strong gradient of morphological change, corresponding with distance from invasion front. This demonstrates a high degree of plasticity in P. parva’s morphology in an invasion context, however this was not linked to either dispersal or activity levels, neither of which was significantly linked to distance from invasion front. Dispersal was best explained by body size, with larger fish more likely to disperse further.Whilst I found no evidence to suggest that the model predictions (Chapter I) were hampered by differentiation at either lineage or population levels, the findings of Chapter II do highlight the uncertainties surrounding the degree of conservatism in such predictions, mainly owing to the fact that past, native, distribution did not accurately predict the current invaded distribution. The results of Chapters II-IV show broad tolerances and great plasticity in P. parva, which likely underpin this species success as a pan-continental invader. The knowledge produced in this thesis provides a useful new resource for the development of management strategies for P. parva and could be usefully enhanced by the additional of analogous studies on native populations, which could help elucidate the source of the observed plasticity
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Hunt, Richard Joseph. "The effect of Australian gudgeon (Hypseleotris spp.) on phytoplankton in a subtropical reservoir, and implications for food web manipulation /". St. Lucia, Qld, 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17759.pdf.
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Burnard, Dean. "Reproductive chemical cues in two freshwater fishes : topmouth gudgeon Pseudorasbora parva (Temminck and Schlegel) and sunbleak Leucaspius delineatus (Heckel)". Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54934/.
Testo completoAbstract (sommario):
The use of reproductive chemical cues is widespread amongst fishes. However, the most understood sex pheromone systems derive from species that employ a scramble spawning reproductive strategy. This thesis investigated for the first time the use of reproductive chemical communication in topmouth gudgeon
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Meredith, Shaun Nicholas. "Ecology and bioenergetics of the gudgeon (Hypseleotris spp.) in Maroon Dam: a zooplanktivorous fish in a whole-lake biomanipulation". Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16184/1/Shaun_Meredith_Thesis.pdf.
Testo completoAbstract (sommario):
Gudgeon (Hypseleotris spp.) are the most widespread and abundant native Australian freshwater fish and the dominant zooplanktivore in Maroon Dam, the site of Australia's first whole-lake biomanipulation experiment. The spatial (littoral and pelagic) and temporal (diurnal and seasonal) distribution and diet of Hypseleotris was examined following the addition of 100,000 piscivorous Australian Bass (Macquaria novemaculeata) to Maroon Dam in the summer of 1998/99. A strong spatial and temporal ontogeny was observed, with smaller (<16 mm SL) Hypseleotris dominating the pelagic, an intermediate (12-20 mm SL) size class diurnally migrating between littoral and pelagic, and larger fish (>20 mm SL) remaining in the littoral throughout the day and night. Spatial ontogeny affected diet also, with fish consuming a decreasing proportion of zooplankton and an increasing proportion of macro-invertebrates as fish length increased and habitat use changed. A bioenergetics model was constructed to examine these distribution and diet patterns. Laboratory derived consumption and respiration parameters were combined with caloric densities and commonly accepted excretion and activity scalars to produce modeled growth estimates that were validated against Hypseleotris age-at-growth data collected from a diversity of habitats. Using this model, it was concluded that the spatial and temporal ontogeny and diet of Hypseleotris in Maroon Dam described the most energetically advantageous life history. Unlike many zooplanktivores in northern hemisphere lakes, Hypseleotris did not appear to engage in migratory predator avoidance behaviour. This is discussed in a context of Australia's paucity of pelagic piscivores. It is concluded that top-down biomanipulation by stocking of native piscivores has only a limited application in Australia, and that other biomanipulation techniques may prove more successful.
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Meredith, Shaun Nicholas. "Ecology and bioenergetics of the gudgeon (Hypseleotris spp.) in Maroon Dam: a zooplanktivorous fish in a whole-lake biomanipulation". Queensland University of Technology, 2005. http://eprints.qut.edu.au/16184/.
Testo completoAbstract (sommario):
Gudgeon (Hypseleotris spp.) are the most widespread and abundant native Australian freshwater fish and the dominant zooplanktivore in Maroon Dam, the site of Australia's first whole-lake biomanipulation experiment. The spatial (littoral and pelagic) and temporal (diurnal and seasonal) distribution and diet of Hypseleotris was examined following the addition of 100,000 piscivorous Australian Bass (Macquaria novemaculeata) to Maroon Dam in the summer of 1998/99. A strong spatial and temporal ontogeny was observed, with smaller (<16 mm SL) Hypseleotris dominating the pelagic, an intermediate (12-20 mm SL) size class diurnally migrating between littoral and pelagic, and larger fish (>20 mm SL) remaining in the littoral throughout the day and night. Spatial ontogeny affected diet also, with fish consuming a decreasing proportion of zooplankton and an increasing proportion of macro-invertebrates as fish length increased and habitat use changed. A bioenergetics model was constructed to examine these distribution and diet patterns. Laboratory derived consumption and respiration parameters were combined with caloric densities and commonly accepted excretion and activity scalars to produce modeled growth estimates that were validated against Hypseleotris age-at-growth data collected from a diversity of habitats. Using this model, it was concluded that the spatial and temporal ontogeny and diet of Hypseleotris in Maroon Dam described the most energetically advantageous life history. Unlike many zooplanktivores in northern hemisphere lakes, Hypseleotris did not appear to engage in migratory predator avoidance behaviour. This is discussed in a context of Australia's paucity of pelagic piscivores. It is concluded that top-down biomanipulation by stocking of native piscivores has only a limited application in Australia, and that other biomanipulation techniques may prove more successful.
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Simon, Andrea. "Genetic factors affecting establishment during invasions : the introduction of the topmouth gudgeon (Pseudorasbora parva) and the rainbow trout (Oncorhynchus mykiss) in Europe". Thesis, University of Hull, 2012. http://hydra.hull.ac.uk/resources/hull:6254.
Testo completoAbstract (sommario):
The study of biological invasions is a major research topic, both because of the ecological and economical damage caused by invasive species and also as a great natural experiment to study evolutionary responses of non-native populations to their new environment, and the factors influencing invasions. Introduced species often evolve rapidly, despite the assumed loss of genetic variation associated with bottlenecks during the invasion process. In order examine the processes and mechanisms affecting the outcome invasions I studied two non-native fish species, the topmouth gudgeon (Pseudorasbora parva) is an Asian cyprinid that is found in most European countries as a result of accidental introductions. Rainbow trout (Oncorhynchus mykiss) has been introduced from the United States for aquaculture and angling, however, despite numerous introductions, it has only been able to establish in few European waters. I used mitochondrial DNA and microsatellite markers to understand the invasion history of these species and the factors that influence their establishment success/failure. Part of the cytochrome b gene was analysed in European and native Asian P. parva populations and microsatellite markers were used to investigate the source populations of the species. The analyses elucidated the colonisation pattern of P. parva in Europe and supported the hypothesis that the species spread through long-distance and stepping-stone methods and originate from admixed source populations. In O. mykiss, part of the d-loop region of the mitochondrial genome was analysed to compare the phylogeographic structure of native US and introduced European populations to examine the spread of the species outside its native range, as well as to find out whether the resistant Hofer strain is the source population of the European rainbow trout populations. I found that European populations are likely to originate from various sources, mainly from California. The Hofer strain is likely to have contributed to some of the wild European populations. Assessing the role of these processes is fundamental in understanding invasive species and finding suitable management practices to control them. From an evolutionary point of view, I was able to detect some of the processes that are important during invasions, in these studies particularly the role of multiple introductions and introduction from genetically admixed source populations.
Libri sul tema "Gudgeon"
1
Find 'em, chase 'em, sink 'em: The mysterious loss of the WWII submarine USS Gudgeon. Guilford, Connecticut: Lyons Press, an imprint of Globe Pequot Press, 2012.
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2
The Gudge Creek and Wad chronicles. Fayetteville: University of Arkansas Press, 1989.
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3
Jackson, Sylvia J. Gash genealogy: A history and genealogy of the immigrant Martin Alley Gash and his descendants and related families who migrated from the Old Dominion--Gudger, Longmire, Whitlow, Woodfin, Young, and others. Oklahoma City, OK (P.O. Box 19648, Oklahoma City 73144-0648): S.J. Jackson, 1998.
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4
Everard, Mark. Gudgeon: The Anglers Favourite Tiddler. CRC Press LLC, 2022.
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Everard, Mark. Gudgeon: The Angler's Favourite Tiddler. Taylor & Francis Group, 2022.
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Everard, Mark. Gudgeon: The Angler's Favourite Tiddler. Taylor & Francis Group, 2022.
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Everard, Mark. Gudgeon: The Angler's Favourite Tiddler. Taylor & Francis Group, 2022.
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8
Everard, Mark. Gudgeon: The Anglers Favourite Tiddler. CRC Press LLC, 2022.
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9
Dolphins, the Whales and the Gudgeon. Penguin Books, Limited, 2015.
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10
Aesop. Dolphins, the Whales and the Gudgeon. Penguin Books, Limited, 2015.
Cerca il testo completoCapitoli di libri sul tema "Gudgeon"
1
Everard, Mark. "Introduction". In Gudgeon, 1–2. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003311010-1.
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Everard, Mark. "What Is a Gudgeon?" In Gudgeon, 3–17. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003311010-2.
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Everard, Mark. "Gudgeon Fishing". In Gudgeon, 19–43. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003311010-3.
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Everard, Mark. "Gudgeon and People". In Gudgeon, 45–66. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003311010-4.
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Bona, F., A. Strozzi e P. Vaccari. "On the Pressure Distribution at the Contact between Small End of a Conrod and Gudgeon Pin". In AMST ’99, 745–52. Vienna: Springer Vienna, 1999. http://dx.doi.org/10.1007/978-3-7091-2508-3_85.
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Czerniejewski, Przemysław, Adam Brysiewicz, Kinga Zatoń e Natalia Kasowska. "Habitats and Density of the Invasive Topmouth Gudgeon (Pseudorasbora parva Schlegel) in Small Polish Watercourses, in the Light of Threats to the Habitats of Native Species of Fishes". In Infrastructure and Environment, 154–60. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-16542-0_21.
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Blinder, Caroline. "Animating the Gudgers: On the Problems of a Cinematic Aesthetic in Let Us Now Praise Famous Men". In New Critical Essays on James Agee and Walker Evans, 145–63. New York: Palgrave Macmillan US, 2010. http://dx.doi.org/10.1057/9780230111868_8.
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"gudgeon". In Shakespeare and Animals. The Arden Shakespeare, 2022. http://dx.doi.org/10.5040/9781350002548.article-115.
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"NELSON, Rev. John Gudgeon (1818–1882)". In Dictionary Of British And Irish Botantists And Horticulturalists Including plant collectors, flower painters and garden designers, 2273–74. CRC Press, 2002. http://dx.doi.org/10.1201/b12560-1175.
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"Pseudorasbora parva Temminck & Schlegel (topmouth gudgeon)". In A Handbook of Global Freshwater Invasive Species, 281–90. Routledge, 2012. http://dx.doi.org/10.4324/9780203127230-34.
Testo completoAtti di convegni sul tema "Gudgeon"
1
Liu, Shi-ying, Zhi-ming Wang e Xiao-qing Tian. "Stress Analysis and Durability Study of Gasoline Engine Piston Gudgeon Pin-hole Structure". In Asia Pacific Automotive Engineering Conference. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2007. http://dx.doi.org/10.4271/2007-01-3710.
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2
Wilson, Jason T., Chi-Ying Lin e Tsu-Chin Tsao. "Design and Control of Fast Tool Servo for Boring of Engine Piston Pin Holes". In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-16191.
Testo completoAbstract (sommario):
This paper presents the mechanical and servo control design of a fast tool servo for machining noncircular bores. The rotating boring bar varies the depth of cut dynamically to machine noncircular bores, such as those in engine piston gudgeon pin holes. The piezoelectric actuator driven fast tool servo has 60 micron displacement and about 400 Hz first natural frequency. The design of robust repetitive control of the fast tool servo is discussed and experimental results of cutting tool motion for generating oval bore profiles are presented.
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Soong, K., e B. S. Thompson. "An Experimental Investigation of the Dynamic Response of a Mechanical System With Bearing Clearance". In ASME 1987 Design Technology Conferences. American Society of Mechanical Engineers, 1987. http://dx.doi.org/10.1115/detc1987-0106.
Testo completoAbstract (sommario):
Abstract Numerous publications have been devoted to the development of analytical and computational models for predicting the dynamic response of mechanical systems comprising assemblages of rigid-bodies with clearance at the joints. However, there is a dearth of experimental investigations in this area which focus on furnishing complementary response data, consequently the predictive capabilities of these theoretical models are largely unknown. The experimental investigation presented herein, is motivated by this observation and is directed towards partially filling this significant void in the literature. In order to accomplish this goal, a comprehensive experimental study was undertaken of a slider-crank mechanism in which the radial clearance at the gudgeon-pin bearing was carefully controlled. Response data at different operating speeds are presented, along with an investigation of the bearing characteristics from which the coefficient of restitution, which features in many of the proposed mathematical models, was evaluated. Finally, design guidelines are distilled from the experimental data to relate the response of the system to the response of a similar system without bearing clearance.
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Traversari, Riccardo, Alessandro Rossi e Marco Faretra. "Virtual Prototyping Technique Applied to the Design of a Process Reciprocating Compressor". In ASME 2011 World Conference on Innovative Virtual Reality. ASMEDC, 2011. http://dx.doi.org/10.1115/winvr2011-5550.
Testo completoAbstract (sommario):
Virtual Prototyping (VP) reproduces a complete machine to test it several times, as a scale 1:1 laboratory prototype. VP utilizes various CAE tools, such as 3D modelling, Structural FEA, Multibody Dynamic Analysis (MDA), Multiaxial fatigue analysis, and Fluid Structure Interaction (FSI) in an integrated way. The VP of a rotating machine allows considering a realistic stepless loading pattern throughout the complete revolution and determining automatically the fatigue safety factors within the whole machine structural assembly, while FSI allows dealing simultaneously with thermodynamic, motion and deformation phenomena. This approach was used to review the design of the crank mechanism and cylinders of an existing reciprocating compressor. The loads (including inertia forces) were applied to the gudgeon pin and, by means of the MDA, to all the other components. An advanced approach, based on Fluid Structure Interaction (FSI) analysis, was applied for the thermodynamic analysis of the cylinder’s efficiency. A 3D CFD Model, simulating the cylinder with mobile piston and valves, was developed and experimentally validated. The 3D domain simulating the compression chamber changes with the piston motion law while valve rings move according to the fluid dynamic forces.
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Agarwal, Avinash Kumar, e Atul Dhar. "Experimental Investigations of Engine Durability and Lubricating Oil Properties of Jatropha Oil Blends Fuelled DI Diesel Engine". In ASME 2009 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/icef2009-14116.
Testo completoAbstract (sommario):
Current demand of transport fuel requires exploring every possible plant resource of engine fuel which can deliver satisfactory performance, emission, combustion and engine durability. Blending smaller quantity of Jatropha oil with mineral diesel is one of the simplest alternatives which can be put into application from technical and availability perspective. High viscosity of Jatropha oil (vegetable oil) comes into acceptable range upon blending with mineral diesel upto 20% (v/v). After ensuring satisfactory performance, emission and combustion characteristics, engines were subjected to long-term endurance test of 512 hour for comparing long-term performance of J5 and J10 blends vis-a`-vis mineral diesel, in the present experimental investigation. In the long-term endurance test, the effect of use of Jatropha oil blends on wear of various engine parts and lubricating vis-a`-vis mineral diesel were evaluated. The deposits on the vital engine parts were found to be slightly higher on J10 fuelled engine while it was comparable to mineral diesel for J5 fuelled engine. The piston rating carried out on the pistons of the three engines reflected that the J5 fuelled engines demonstrated reasonable long-term performance in comparison to mineral diesel fuelled engine while performance of J10 fuelled engine was slightly inferior. J5 and J10 fuelled engine’s lubricating oil shows higher reduction in lubricating oil viscosity and flash point compared to mineral diesel, thus indicating possibly higher fuel dilution. Fe, Pb, Cr, Zn wear metal debris in the lubricating oil are lower for J5 and J10 compared to mineral diesel engine’s lubricating oil however Al content in the lubricating oil is slightly higher for J5 and J10 compared to mineral diesel engine’s lubricating oil. Physical wear measurement of vital engine parts indicate relatively higher wear of liner bore, piston rings and big end bearing for J5 and J10 fuelled engine while wear of valve mounting, piston, gudgeon pin, crank pin was found to be relatively lower than mineral diesel fuelled engine. It was found that the wear of J5 engine liners is higher compared to mineral diesel fuelled engine. However wear of J10 fuelled engine liner is found to be relatively lower compared to mineral diesel fuelled engine.