References of "Ovidio, Michaël"
     in
Bookmark and Share    
Full Text
See detailBases biologiques et éco-hydrauliques pour la restauration de la continuité piscicole en rivière : premier bilan et perspectives en Région Wallonne (Belgique).
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg; Denoel, Philippe et al

Conference (2008, October)

Dans le prolongement de la Directive Benelux d’avril 1996 (libre circulation des poissons migrateurs) et de la Directive Cadre sur l’Eau de l’Union Européenne (2000/60/CE), le rétablissement de la ... [more ▼]

Dans le prolongement de la Directive Benelux d’avril 1996 (libre circulation des poissons migrateurs) et de la Directive Cadre sur l’Eau de l’Union Européenne (2000/60/CE), le rétablissement de la continuité piscicole dans nos cours d’eau fait partie des objectifs prioritaires de la Direction des Cours d’eau Non Navigables du Ministère de la Région Wallonne. Depuis 1997, différents acteurs, gestionnaires, sociétés de pêches et scientifiques abordent en profondeur cette problématique par l’exécution de différentes actions intégrées. Depuis environ 10 ans, un travail de terrain considérable est accompli pour le compte de la Région wallonne par la Fédération de Pêche Vesdre-Amblève (asbl) qui répertorie et géoréférence la totalité des obstacles physiques susceptibles de perturber la continuité piscicole dans les cours d’eau de Wallonie. En parallèle, le Laboratoire de Démographie des Poissons et d’Hydroécologie (LDPH) de l’Université de Liège étudie l’impact biologique de certains de ces obstacles sur les populations de poissons, principalement en utilisant la technique du radio-pistage. Ces recherches permettent de mieux connaître les phénomènes de mobilité et de migrations des poissons de nos cours d’eau ainsi que leurs capacités à franchir en remontée des obstacles typologiquement très différents. Ces travaux permettent d’identifier les sites critiques qui doivent prioritairement êtres équipés de dispositifs de franchissement efficaces. Le contrôle scientifique du fonctionnement des passes migratoires nouvellement construites démontre clairement leurs effets positifs sur la qualité écologique et piscicole de la rivière. De tels résultats justifient fortement de multiplier ce type d’action de restauration écologique (hydromorphologique) dans d’autres cours d’eau. Au cours de notre exposé, nous présenterons, avec des résultats concrets, un premier bilan des travaux déjà effectués et nous dégagerons les perspectives à moyen et long terme en matière de libre circulation des poissons dans les cours d’eau wallons, non seulement en remontée mais aussi en descente (ou dévalaison). [less ▲]

Detailed reference viewed: 40 (3 ULg)
Full Text
Peer Reviewed
See detailUpstream migration of fish at natural obstructions and fish passes efficiency in Southern Belgium.
Ovidio, Michaël ULg; Orban, Patrice; Lambot, Francis et al

Conference (2008, July)

Fragmentation of rivers by physical obstacles has resulted in the drastic range reduction or extinction of numerous diadromous and potadromous species of fish worldwide. In order to implement to partially ... [more ▼]

Fragmentation of rivers by physical obstacles has resulted in the drastic range reduction or extinction of numerous diadromous and potadromous species of fish worldwide. In order to implement to partially or completely re-establish the free movements of fish in the entire watercourse, the Walloon regional government (Southern Belgium) initiated an integrated restoration project whose objectives are 1) To perform a complete inventory of all obstacles that may potentially interfere with the longitudinal connectivity and the free movements of fish, 2) To test, using radio telemetry, the ability of representative fish species (Salmonidae, Thymallidae, Cyprinidae, Esocidae and Cottidae) to clear different typologies of physical obstacles, 3) To determine the problematic sites that should be improved with priority. 4) To construct fish passage facilities and to examine their biological efficiencies. During our talk we will synthesize the results of ten years of research and define the different options for the future. [less ▲]

Detailed reference viewed: 40 (4 ULg)
Full Text
Peer Reviewed
See detailThe restoration of the longitudinal connectivity in Southern Belgian rivers. Synthesis of a 10-years study and perspectives
Ovidio, Michaël ULg; Orban, Patrice; Lambot, Francis et al

Conference (2008, June)

Detailed reference viewed: 21 (4 ULg)
See detailConvention d’études pour le suivi scientifique de la réhabilitation du saumon atlantique dans le bassin de la Meuse
Micha, Jean-Claude; Malbrouck, Christelle; Fossion, Pierre et al

Report (2008)

Detailed reference viewed: 7 (1 ULg)
Full Text
Peer Reviewed
See detailFertility in first-generation hybrids of roach, Rutilus rutilus (L.), and silver bream, Blicca bjoerkna (L.)
Nzau Matondo, Billy; Nlemvo, A. B.; Ovidio, Michaël ULg et al

in Journal of Applied Ichthyology (2008), 24(1), 63-67

Fertility in first-generation hybrids of roach, Rutilus rutilus, and silver bream, Blicca bjoerkna, was investigated. Sperm and egg production of hybrids at first sexual maturity were examined. Eggs from ... [more ▼]

Fertility in first-generation hybrids of roach, Rutilus rutilus, and silver bream, Blicca bjoerkna, was investigated. Sperm and egg production of hybrids at first sexual maturity were examined. Eggs from female hybrids were artificially fertilized with the sperm of a corresponding hybrid male; a hybrid male from the reciprocal crossbreeding; a parental species male R. rutilus; and a parental species male B. bjoerkna. The results revealed that gametogenesis was normal in female hybrids. However, in male hybrids, a low efficiency of gametogenesis was observed. The semen of male hybrids was extremely dilute, with spermatozoa concentration lower than that in parental species. Nevertheless, these F1 hybrids (males and females) from reciprocal crossbreeding were fertile. F2 and backcross generations were produced, but F2 crosses from the female hybrid and corresponding hybrid male displayed a drastically slower hatching rate. Also higher proportions of deformed embryos were hatched than in other post-F1-generation crosses. [less ▲]

Detailed reference viewed: 58 (11 ULg)
Full Text
Peer Reviewed
See detailSexual maturity, reproductive behaviour and fertility in the first-generation hybrids of Blicca bjoerkna L. x Abramis brama L.
Matondo, Billy Nzau; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Cybium (2008), 32(2), 286-289

Sexual maturity, reproductive behaviour and fertility in the artificial first-generation hybrids of silver bream, Blicca bjoerkna, and common bream, Abramis brama, were investigated in this study. The ... [more ▼]

Sexual maturity, reproductive behaviour and fertility in the artificial first-generation hybrids of silver bream, Blicca bjoerkna, and common bream, Abramis brama, were investigated in this study. The results revealed that the females and males of hybrids attained their first sexual maturity at the same age. Maturity in F, hybrids was observed at the same moment as maturity in the common bream, the latter being the parental species. Sizes of male hybrids at maturity were intermediate to their parents but female hybrids were closer to the highest parental species, the common bream. As for reproductive behaviour, the numbers of spawning and mating behaviours observed were highly similar. Female hybrids mated simultaneously and successively with all types of males, except the common bream male. resulting in fertilised eggs. Male hybrids exhibited aggressiveness and territorial activities as in parental species common bream. Successful survival was observed in all post-F-1 (F-2 and backcross) generations at each developmental stage, proving that these hybrids are fertile. [less ▲]

Detailed reference viewed: 68 (4 ULg)
Full Text
Peer Reviewed
See detailMorphological recognition of artificial F1 hybrids between three common European cyprinid species: Rutilus rutilus, Blicca bjoerkna and Abramis brama.
Matondo, B. N.; Ovidio, Michaël ULg; Poncin, Pascal ULg et al

in Dong Wu Xue Bao = Acta Zoologica Sinica (2008), 54(1),

The F1 hybrids of roach Rutilus rutilus, silver bream Blicca bjoerkna, and common bream Abramis brama from experimental reciprocal cross-breedings were identified at 18 months of age in relation to the ... [more ▼]

The F1 hybrids of roach Rutilus rutilus, silver bream Blicca bjoerkna, and common bream Abramis brama from experimental reciprocal cross-breedings were identified at 18 months of age in relation to the parental species. The morphological analysis, including quantitative (plastic and meristic) and nonmetric features differing in the roach, the silver bream and the common bream, revealed that roach * common bream and roach * silver bream hybrids were easier to distinguish from their parents than silver bream * common bream hybrids. These roach hybrids had many morphological similarities such as the upper iris coloured in red as in the roach, and they were morphologically intermediate to the two parents. This contrasted with the silver bream * common bream hybrids, in which intermediate characteristics were also observed, but with some parental variants. Roach * silver bream hybrids were distinguishable from roach * common bream hybrids by its large eye, its lower scale numbers along the lateral line and its two rows of pharyngeal teeth. Silver bream * common bream hybrids, compared to the two other types of hybrids studied, had higher anal fin soft ray numbers and a clear eye iris with a median black line. In all interspecific crosses of these three cyprinid species fish, the reciprocal hybrids were generally indistinguishable. [less ▲]

Detailed reference viewed: 107 (10 ULg)
Full Text
Peer Reviewed
See detailRegulated discharge produces substantial demographic changes on four typical fish species of a small salmonid stream
Ovidio, Michaël ULg; Capra, Hervé; Philippart, Jean-Claude ULg

in Hydrobiologia (2008), 609

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP ... [more ▼]

A hydroelectric power plant (HPP) started operation in December 2002 on the River Lhomme, (mean annual flow: 1.78 m(3) s(-1)supercript stop; mean annual water temperature: 9.9 degrees C). The new HPP bypasses the river over a length of 1.2 km. The minimum flow allowed in the bypassed section is currently fixed at 0.220 m(3) s(-1)supercript stop. Before the construction of the HPP, two contrasted 150-m-long reaches of the Lhomme were selected to estimate their total fish population abundance and to analyse their fish population dynamics. Electrofishing was carried out in each of these two reaches on 23 April 2002 in a natural flow situation to remove the fish. Other inventories were carried out in late April or early May in 2003, 2004, 2005 and 2006 in minimum flow conditions. The results revealed a prompt and severe decrease in the total fish biomass (up to 81% for grayling from 2002 to 2006) combined with severe changes in the fish community structure that were not observed in a reference site. The effects of the flow reduction varied considerably depending on the size of the individuals, the species concerned and their habitat availability, which was modelled using a classical physical habitat simulation (EVHA method). [less ▲]

Detailed reference viewed: 94 (28 ULg)
Full Text
Peer Reviewed
See detailMovement patterns and spawning activity of individual nase Chondrostoma nasus (L.) in flow-regulated and weir-fragmented rivers
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg

in Journal of Applied Ichthyology (2008), 24(3), 256-262

Eighteen adult nase Chondrostoma nasus (L.) (37.6-48.2 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters and manually tracked from the banks of ... [more ▼]

Eighteen adult nase Chondrostoma nasus (L.) (37.6-48.2 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters and manually tracked from the banks of the rivers for 3-34 weeks. Their movements were mainly recorded during the circum reproduction period in 2001, 2002 and 2006 in river stretches delimited by physical barriers and/or minimum flow conditions. To reach the spawning grounds, nase displayed different patterns of movements that were mainly influenced by the configuration of the study site, the date of observation and the associated environmental conditions. Nase never cleared any physical obstacle but were able to spawn in minimum flow conditions or just downstream from physical obstacles. Nase were present on spawning grounds in late March in the warmest spring (2001) and from mid-April to early May in the coldest spring (2006). After spawning, a major proportion of C. nasus migrated a substantial distance downstream, whereas others remained near their capture site and showed frequent movements, sometimes corresponding to group displacements from one river to another. [less ▲]

Detailed reference viewed: 116 (21 ULg)
Full Text
Peer Reviewed
See detailMating patterns of first-generation hybrids of the roach, Rutilus rutilus (L.), and the silver bream, Blicca bjoerkna (L.)
Nzau Matondo, Billy; Ovidio, Michaël ULg; Philippart, Jean-Claude ULg et al

in Journal of Ethology (2008), 26(1), 179-183

Mating patterns among first-generation hybrids of the roach, Rutilus rutilus, and the silver bream, Blicca bjoerkna, between hybrids or with parent-species males, have been investigated under experimental ... [more ▼]

Mating patterns among first-generation hybrids of the roach, Rutilus rutilus, and the silver bream, Blicca bjoerkna, between hybrids or with parent-species males, have been investigated under experimental reproduction conditions. The results reveal that the level of sexual activity of these hybrids is high. Hybrid females mated simultaneously and successively with all types of male, resulting in fertilised eggs. Individual participation of roach males in mating was never observed, however. [less ▲]

Detailed reference viewed: 48 (7 ULg)
Full Text
See detailLa migration de remontée de l’anguille dans le bassin de la Meuse
Philippart, Jean-Claude ULg; Ovidio, Michaël ULg

Scientific conference (2007, November 07)

Detailed reference viewed: 19 (1 ULg)
Full Text
Peer Reviewed
See detailHybridization success of three common European cyprinid species, Rutilus rutilus, Blicca bjoerkna and Abramis brama and larval resistance to stress tests
Nzau Matondo, Billy; Ovidio, Michaël ULg; Poncin, Pascal ULg et al

in Fisheries Science (2007), 73(5), 1137-1146

Hybridization success at early developmental stages and larval resistance to osmotic, thermal and fasting tests in roach Rutilus rutilus, silver bream Blicca bjoerkna, common bream Abramis brama and their ... [more ▼]

Hybridization success at early developmental stages and larval resistance to osmotic, thermal and fasting tests in roach Rutilus rutilus, silver bream Blicca bjoerkna, common bream Abramis brama and their F1 hybrids were investigated. Results revealed that hybrid survival rates were similar to parents. At the eyed embryo stage, however, a maternal effect was observed as a general trend during hatchling and larval stages. After these stages, hybrids displayed a higher survival rate than their parents. Under stress tests, no survival was observed after 40 min for osmotic and thermal shocks and after 24 days for the prolonged fasting test in these species and their F1 hybrids. The median survivals of hybrids were intermediate between the two parents. For total mortality, hybrids were also affected by a maternal effect but to the advantage of the hybrids. [less ▲]

Detailed reference viewed: 52 (8 ULg)
Full Text
Peer Reviewed
See detailMultiyear homing and fidelity to residence areas by individual barbel (Barbus barbus)
Ovidio, Michaël ULg; Parkinson, Denis; Philippart, Jean-Claude ULg et al

in Belgian Journal of Zoology (2007), 137(2), 183-190

Nine barbels (Barbus barbus) from the River Ourthe (River Meuse basin) were equipped with transmitters programmed to switch ON during two consecutive spawning seasons in 1998 and 1999 (April to July). Six ... [more ▼]

Nine barbels (Barbus barbus) from the River Ourthe (River Meuse basin) were equipped with transmitters programmed to switch ON during two consecutive spawning seasons in 1998 and 1999 (April to July). Six of the nine barbels tracked in 1998 were also tracked in 1999 during the same period. The length of the spawning migration ranged from 200 to 22700m. After the spawning activity observed from 12-16 May 1998 and 4-6 May 1999, the barbels homed to the site occupied before spawning. Each barbel used the same spawning area in 1998 and 1999, despite the presence of other spawning sites on their migratory route. These observations revealed the existence of strict reproductive homing in the barbel and a long-term fidelity to particular resting places. [less ▲]

Detailed reference viewed: 97 (23 ULg)
Full Text
Peer Reviewed
See detailDoes turbulence affect the habitat choice of Atlantic salmon parr?
Enders, Eva C; Ovidio, Michaël ULg; Roy, Mathieu L et al

Conference (2007, June)

Habitat preferences of Atlantic salmon parr are commonly described using mean flow velocity, water depth, and substrate as habitat variables, and a variety of habitat models have been developed using ... [more ▼]

Habitat preferences of Atlantic salmon parr are commonly described using mean flow velocity, water depth, and substrate as habitat variables, and a variety of habitat models have been developed using these variables to predict habitat quality. However, Atlantic salmon parr live in highly turbulent streams and rivers, in which intense fluctuations of flow velocity occur. Habitat preferences that consider the high variability of flow velocity have not been studied, and this although it has been shown in laboratory experiments that turbulence may affect the behavior and energetics of fish. Consequently, we studied the use of turbulent flow by Atlantic salmon parr in Patapédia River, Québec, Canada using radio-telemetry. We analyzed summer habitat preferences of individual parr in relation to several dynamic hydraulic variables such as standard deviation of flow velocity, turbulent kinetic energy, Froude number, and shear stress, and compared them with the habitat availability within the river reach. Our results revealed that in a natural flow environment, parr display a high individual variability in habitat preferences in relation to flow turbulence. Such heterogeneous habitat preferences suggest that individuals are not constrained to single habitat types and exhibit flexible habitat use. Furthermore, no differences were observed in habitat preferences between the four daily periods (dawn, day, dusk, and night) within individual parr. [less ▲]

Detailed reference viewed: 32 (2 ULg)