References of "Ovidio, Michaël"
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See detailSur quelles connaissances se baser pour évaluer l’état de santé des populations de truite commune (Salmo trutta)?
Gouraud, Véronique; Baran, Philippe; Bardonnet, Agnès et al

in Hydroécologie appliquée (2014)

Le retour au premier plan de la notion de santé des écosystèmes met en évidence la préoccupation de la société à mettre en oeuvre des mesures pour la protection des milieux anthropisés. Les critères ... [more ▼]

Le retour au premier plan de la notion de santé des écosystèmes met en évidence la préoccupation de la société à mettre en oeuvre des mesures pour la protection des milieux anthropisés. Les critères d’évaluation de la santé des peuplements piscicoles mis en oeuvre sont rarement débattus au sein de la communauté scientifique. L’exercice proposé ici devait permettre d’avoir ce débat sur la truite commune (Salmo trutta), espèce phare des cours d’eau situés en tête de bassin, qui représentent la majorité du réseau hydrographique français. La démarche visait à recueillir la conception qu’avait un nombre restreint d’experts, sur le fonctionnement de ces populations et sur les critères d’évaluation de leur fonctionnement. Les paramètres clé régulant chaque stade de développement ont été identifiés et hiérarchisés. Unconsensus s’est dégagé sur le fait que, dans l’état actuel des connaissances, le diagnostic peut être établi sur la base de l’analyse des paramètres abiotiques essentiels pour la biologie et, plus difficilement, sur l’analyse des paramètres biotiques. Pour tous les stades de développement, les paramètres identifiés sont liés à l’habitat (qualité du substrat, conditions hydrauliques, température et qualité de l’eau), l’hydrologie et la connectivité. Des connaissances demandent d’être acquises pour définir des critères biologiques. Cela implique de renforcer la surveillance biologique à long terme et les actions de recherche pour caractériser la variabilité des paramètres biologiques et identifier les échelles spatio-temporelles pertinentes et les processus fonctionnels. [less ▲]

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See detailEssai d’estimation des dommages piscicoles engendrés par les prises d’eau industrielles et les turbines hydroélectriques dans les cours d’eau de la Province de Liège. Partie F. Les centrales hydro-électriques sur la Vesdre
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg; Rimbaud, Gilles ULg et al

Report (2013)

Ce rapport à la Commission provinciale de Liège du Fonds piscicole de Wallonie est un dossier bibliographique qui analyse l’impact potentiel sur les populations de poissons des neuf centrales ... [more ▼]

Ce rapport à la Commission provinciale de Liège du Fonds piscicole de Wallonie est un dossier bibliographique qui analyse l’impact potentiel sur les populations de poissons des neuf centrales hydroélectriques installées dans le sous-bassin hydrographique de la Vesdre. [less ▲]

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See detailContribution to the study of acoustic communication in two Belgian river bullheads (Cottus rhenanus and C. perifretum) with further insight into the sound-producing mechanism
Colleye, Orphal ULg; Ovidio, Michaël ULg; Salmon, André et al

in Frontiers in Zoology (2013), 10(71),

Background: The freshwater sculpins (genus Cottus) are small, bottom-living fishes widely distributed in North America and Europe. The taxonomy of European species has remained unresolved for a long time ... [more ▼]

Background: The freshwater sculpins (genus Cottus) are small, bottom-living fishes widely distributed in North America and Europe. The taxonomy of European species has remained unresolved for a long time due to the overlap of morphological characters. Sound production has already been documented in some cottid representatives, with sounds being involved in courtship and agonistic interactions. Although the movements associated with sound production have been observed, the underlying mechanism remains incomplete. Here, we focus on two closely related species from Belgium: C. rhenanus and C. perifretum. This study aims 1) to record and to compare acoustic communication in both species, 2) to give further insight into the sound-producing mechanism and 3) to look for new morphological traits allowing species differentiation. Results: Both Cottus species produce multiple-pulsed agonistic sounds using a similar acoustic pattern: the first interpulse duration is always longer, making the first pulse unit distinct from the others. Recording sound production and hearing abilities showed a clear relationship between the sound spectra and auditory thresholds in both species: the peak frequencies of calls are around 150 Hz, which corresponds to their best hearing sensitivity. However, it appears that these fishes could not hear acoustic signals produced by conspecifics in their noisy habitat considering their hearing threshold expressed as sound pressure (~ 125 dB re 1 ␣Pa). High-speed video recordings highlighted that each sound is produced during a complete back and forth movement of the pectoral girdle. Conclusions: Both Cottus species use an acoustic pattern that remained conserved during species diversification. Surprisingly, calls do not seem to have a communicative function. On the other hand, fish could detect substrate vibrations resulting from movements carried out during sound production. Similarities in temporal and spectral characteristics also suggest that both species share a common sound-producing mechanism, likely based on pectoral girdle vibrations. From a morphological point of view, only the shape of the spinelike scales covering the body allows species differentiation. [less ▲]

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See detailTechniques de marquages et de suivis de poissons de repeuplement
Ovidio, Michaël ULg

Conference (2013, November 05)

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See detailHow did endemic cyprinids and exotic european catfish move in a large river ecosystem?
Capra, Hervé; Pella, Hervé; Ovidio, Michaël ULg

Conference (2013, October 03)

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See detailLes connections longitudinales en rivières
Ovidio, Michaël ULg

Scientific conference (2013, September 17)

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See detailA bit of quiet between the migrations: the resting life of the European eel during their freshwater growth phase in a small stream
Ovidio, Michaël ULg; Seredynski, Aurore ULg; Philippart, Jean-Claude ULg et al

in Aquatic Ecology (2013), 47

The movements and habitat use of resident yellow eels were studied in a stream stretch having both natural and minimum flow zones. N = 12 individuals (total length 505–802 mm) were surgically tagged with ... [more ▼]

The movements and habitat use of resident yellow eels were studied in a stream stretch having both natural and minimum flow zones. N = 12 individuals (total length 505–802 mm) were surgically tagged with radio transmitters and released at their capture sites. They were located using manual radio receivers during the daytime from 2 to 5 days/ week over periods ranging from 200 to 329 days, for a total of 1,098 positions. Eels showed home ranges ranging from 33 to 341 m (median value, 62 m), displayed strong fidelity to sites and demonstrated a great degree of plasticity in habitat use. Eels were slightly mobile throughout the year, but their movements were season and temperature dependent, with a maximum during the spring (mean water temperature, 12 C) and a minimum in winter (3 C). Stones and roots (utilization rate greater than 50 % of eels for more than 30 % of location days) were significantly the most frequently used habitats. Between the two flow zones, the natural flow was the most occupied, with a significantly higher proportion of resident eels(66.7 % of radio-tagged yellow eels) and longer occupation (81 % of location days) than the minimum flow zone with less suitable habitats. [less ▲]

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See detailEssai d’estimation des dommages piscicoles engendrés par les prises d’eau industrielles et les turbines hydroélectriques dans les cours d’eau de la Province de Liège. Partie E. Chapitre 8. Les centrales hydro-électriques sur la Méhaigne, petit affluent de la Meuse dans le sous-bassin Meuse aval
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg; Rimbaud, Gilles ULg et al

Report (2013)

Ce rapport à la Commission provinciale de Liège du Fonds piscicole de Wallonie est un dossier bibliographique qui analyse l’impact potentiel sur les populations de poissons des quatre centrales ... [more ▼]

Ce rapport à la Commission provinciale de Liège du Fonds piscicole de Wallonie est un dossier bibliographique qui analyse l’impact potentiel sur les populations de poissons des quatre centrales hydroélectriques (voir tableau A) installées sur la Méhaige, principal, petit affluent de la rive gauche de la Meuse, sous-bassin Meuse aval. L’impact de la production d’hydroélectricité sur les poissons de la Méhaigne concerne principalement le cours inférieur de la rivière où se succèdent sur une distance de 5,9 km trois micro-centrales qui utilisent un débit de 2-3 m3/s, pratiquement égal au module. L’utilisation d’un tel débit sur aussi petite rivière favorise un fort pourcentage d’entrainement de l’eau et des poissons dévalants dans l’installation de turbinage (turbine Kaplan, turbine Francis ou vis hydrodynamique). Dans ce cas, il faut envisager un effet cumulé de la cascade des trois microcentrales de la Basse Méhaigne. [less ▲]

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See detailSpawning behaviour and mating success in hybrids of silver bream (Blicca bjoerkna L.) and rudd (Scardinius erythrophthalmus L.) in an experimental environment
Nzau Matondo, Billy ULg; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Animal Biology (2013), 63

The egg-release, mating, courting and aggressive acts for the spawning behaviour as well as the survival rates after spawning at stages of eyed embryos, viable hatchlings, and larvae to dry food ... [more ▼]

The egg-release, mating, courting and aggressive acts for the spawning behaviour as well as the survival rates after spawning at stages of eyed embryos, viable hatchlings, and larvae to dry food consumption for the mating success were studied in cultured silver bream Blicca bjoerkna × rudd Scardinius erythrophthalmus hybrids at their first sexual maturity. Experiments were conducted in experimental environments simulating natural reproductive conditions of the parental species. Spawning behaviour was analysed over 1 day from 8.00 to 18.00 hours using a remote-controlled video. Mating success was assessed from eggs and hatched embryos collected on the spawning ground. The results showed that these hybrids exhibited all the reproductive behaviours of the parental species with significantly more courtship than mating. Each egg-release act was accompanied by mating behaviour, involving all the experimental males. A surprising aggressive behaviour was observed in one male which attacked all other experimental fish. Successful mating resulted in the presence of fertilized eggs, the production of hatched embryos in experiments, and the survival of larvae at the dry food consumption stage. However, the low viable hatchling rate observed could indicate a very low chance of survival for these hybrids in rivers in which the occurrence of post-F1 individuals may be more possible by backcrossing. [less ▲]

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See detailEvaluation de la qualité biologique des rivières wallonnes sur base des indices biologiques poissons. Support technique aux inventaires 2012.
Rimbaud, Gilles ULg; Ovidio, Michaël ULg; Dierckx, Arnaud ULg et al

Report (2012)

Ce rapport a pour objectif l’évaluation de la qualité biologique des eaux de surface basée sur les indices biologiques « poissons » dans un certain nombre de cours d’eau de Wallonie. Il résulte d’une ... [more ▼]

Ce rapport a pour objectif l’évaluation de la qualité biologique des eaux de surface basée sur les indices biologiques « poissons » dans un certain nombre de cours d’eau de Wallonie. Il résulte d’une convention entre le Service public de Wallonie et l’Université de Liège. [less ▲]

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See detailA comparative study of sexual product quality in F1 hybrids of the bream Abramis brama X the silver bream Blicca bjoerkna
Nzau Matondo, Billy ULg; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Fisheries Science (2012), 78

The gonadosomatic index at spawning, absolute fecundity, and egg size for the female sexual products as well as the density and consistency of semen for the male sexual products were examined in cultured ... [more ▼]

The gonadosomatic index at spawning, absolute fecundity, and egg size for the female sexual products as well as the density and consistency of semen for the male sexual products were examined in cultured Abramis brama 9 Blicca bjoerkna F1 hybrids and compared with the parental species at their first sexual maturity. Females ovulated under environmental conditions, and their eggs were weighed, counted and measured. Semen of males was macroscopically examined and spermatozoa counted using a hemocytometer. Results revealed that hybridization affected the quality of female and male gametes but with an overlap between hybrids and parents. The gonadosomatic index and fecundity were significantly lower than those of parental species. Egg sizes in hybrids showed a parental effect but to the benefit of hybrids. Semen of hybrids was more diluted which was classified into two groups: the white semen overlapping slightly with parents and the aqueous without any overlap with parents. Overlapped areas between hybrids and parents in term of quality of sexual products could translate that females and males of these hybrids have the biological capacity to produce high quality gametes and thus, a greater chance to produce F2 and backcross generations in rivers. [less ▲]

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See detailBehavioural adaptations of rheophilic fish radio-tracked in a river highly fragmented by hydroelectric plants. Outcomes of a partial reopening of their migration routes.
Ovidio, Michaël ULg; Dierckx, Arnaud ULg; Benitez, Jean-Philippe ULg et al

in Proceedings of the 9th International Conference on Ecohydraulics (2012, September)

Using water resources for hydroelectricity production influences and limits the quality and quantity of habitat available for use by fishes and influences fish mobility. In the Amblève (River Meuse basin ... [more ▼]

Using water resources for hydroelectricity production influences and limits the quality and quantity of habitat available for use by fishes and influences fish mobility. In the Amblève (River Meuse basin, Belgium), the major part of the river is fragmented by hydroelectric power plants that largely prevent the biological movements of the fish population. In 2007, in the hydroelectric site of Lorcé, a modern pool-type fish pass was constructed, re-establishing the upstream movements of fish after more than 80 years of total obstruction. Sixteen different fish species promptly used the new fish pass and the objective of our study was to analyse their behavioural tactics and spawning activity once released upstream of the dam in a previously inaccessible environment. The study focussed on rheophilic holobiotic species, the nase (Chondrostoma nasus), the barbel (Barbus barbus), the European grayling (Thymallus thymallus) and the brown trout (Salmo trutta), which are highly representative of the fish population of the river. The fish were radio-tagged and intensively located using manual tracking techniques during their circum reproduction periods. The results indicate that most individuals of the different species seem to have found usable spawning areas and exploited a large part of the newly usable river stretch (as well as tributaries) located upstream of the fish pass. However, a major problem was observed during the post-spawning period, when the tracked individuals tried to reach their original departure sites (located downstream of the fish pass). The absence of a downstream migration device combined with the passage of all the water through the turbine severely disrupted their post-reproductive movements. [less ▲]

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See detailWhat do we know to evaluate the health of brown trout (Salmo trutta) populations?
Gouraud, Véronique; Baran, Philippe; Bardonnet, Agnès et al

in Proceedings of the 9th International Conference on Ecohydraulics (2012, September)

The renewed emphasis on the concept of the health of ecosystems highlights society’s interest in taking measures to protect environments transformed by human activity. The criteria used for evaluating the ... [more ▼]

The renewed emphasis on the concept of the health of ecosystems highlights society’s interest in taking measures to protect environments transformed by human activity. The criteria used for evaluating the health of fish population are rarely discussed within the scientific community. The exercise proposed here aimed to discuss these for the brown trout (Salmo trutta), a flagship species from the freshwater fish community typical from headwaters of watercourses which represent most of the French hydrographic network. This initiative aimed to gather the ideas of a limited number of experts on the function of these populations and on the criteria for evaluating their function. The main key parameters were identified and organised into a hierarchical framework for each development stage. A consensus emerged on the fact that in the current stage of knowledge, the diagnosis can be established based on the analysis of abiotic parameters crucial for the biology and, with more difficulty, on the analysis of biotic parameters. For all the development stages, the identified parameters are linked to habitat (substrate, stream flow, temperature and water quality), hydrology and connectivity. Further knowledge must be acquired in order to be able to measure the biological criteria. That implies to reinforce longterm biological monitoring and research to understand the variability in biological parameters, the relevant spatiotemporal scales and the functional processes. [less ▲]

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