Environmental unpredictability rules the autumn migration of brown trout (Salmo trutta L.) in the Belgian Ardennes
Ovidio, Michaël ; ; et al
in Hydrobiologia (1998), 372
This telemetry study aimed to document the mobility of Salmo trutta in the River Ourthe sub-basin (tributary of the River Meuse) during summer and autumn, and to analyse the environmental factors which ... [more ▼]
This telemetry study aimed to document the mobility of Salmo trutta in the River Ourthe sub-basin (tributary of the River Meuse) during summer and autumn, and to analyse the environmental factors which trigger spawning migration or limit their extension. Nine trout (233-2217 g and 26.6-55.2 cm FL) were radio-tagged with intraperitoneal radio transmitters and positioned daily, from 14 August 1996 to 15 January 1997. Until 1 October, fish showed restricted movements: daily journeys never exceeded 300 m and corresponded to displacements by high floods or to routine home range movements. From 7 October to 15 November, seven of the nine trout travelled upstream over distances from 5.6 to 22.95 km, into tributaries and sub-tributaries. Migration speed was fast during the early days, when trout could travel over more than 5 km per night, then progressively decreased as they were approaching putative spawning redds under lower temperature. Both ire the River Ourthe and in the Aisne stream, all migrations started within less than three weeks (early October) and were found to be triggered by the combination of three environmental factors: high variations of water temperature and water level between consecutive days, within a thermal range of 10-12 degrees C. From the trout point's of view, these may be signs that the environment becomes unpredictable, as its variability increases within a thermal range which no longer enables them to achieve high growth rates. These results are discussed within the context of foraging strategies, life history strategies and management of trout population. [less ▲]Detailed reference viewed: 61 (16 ULg)
Gonadal and thyroid hormones in the barbel (Barbus barbus) during and outside short reproductive cycles
Poncin, Pascal ; ; et al
in Folia Zoologica (1998), 47
Sex steroids with thyroid hormones were studied during reproduction in the European barbel Barbus barbus L., a new species for European aquaculture. In female barbel, the period between two successive ... [more ▼]
Sex steroids with thyroid hormones were studied during reproduction in the European barbel Barbus barbus L., a new species for European aquaculture. In female barbel, the period between two successive ovulations (every 12-18 days) was characterized by high estradiol-17 beta (E-2) levels (>300 pg.ml(-1)) and a sinusoidal variation of these levels. Outside the reproductive periods, the E-2 plasma concentration was significantly lower (100 pg.ml(-1)) and invariation. The spermiating males showed significantly higher testosterone (T) plasma values than non-spermiating ones. The opposite was noticed for the plasma thyroxine (T-4) concentrations: low values in males and females during reproduction, high values outside reproductive periods. Spermiating males had a higher triiodothyronine (T-3) plasma concentration compared to non-spermiating ones, whereas no significant difference is seen for the females. [less ▲]Detailed reference viewed: 64 (12 ULg)
Feeding in darkness alleviates density-dependent growth of juvenile vundu catfish Heterobranchus longifilis (Clariidae)
; ; et al
in Aquatic Living Resources (1998), 11Detailed reference viewed: 16 (3 ULg)
Behaviour and mobility of radio-tagged Barbus barbus below an hydroelectric dam on the River Ourthe (Belgium).
; ; Ovidio, Michaël et al
Conference (1997, April)Detailed reference viewed: 40 (5 ULg)
Environmental unpredictability rules the autumn migrations of trout (Salmo trutta) in the Belgian Ardennes.
Ovidio, Michaël ; ; et al
Conference (1997)Detailed reference viewed: 10 (1 ULg)
Observations sur l'efficacité de la nouvelle passe à poissons sur l'Aisne à Bomal
Philippart, Jean-Claude ; ; et al
Article for general public (1996)Detailed reference viewed: 22 (3 ULg)
A critical review of surgery techniques for implanting telemetry devices into the body cavity of fish
; ; et al
Conference (1996, August)
Based on literature survey and personal experience, this paper presents a critical review of surgery procedures to implant telemetry devices (transmitters, transponders) into the body cavity of fish ... [more ▼]
Based on literature survey and personal experience, this paper presents a critical review of surgery procedures to implant telemetry devices (transmitters, transponders) into the body cavity of fish species. It debates on the relative adequacy of techniques which may compromise or enhance tagging success with respect to fish health and transmitter retention: anaesthesia, incision (position and length of incision), transmitter features (size and weight ratios, coating), ways of closing the incision (stitches, staples, adhesives), prophylaxy, pre- and postoperative care. Behavioural and physiological biases originating from tagging or internal presence of the transmitter are reviewed, evaluated and integrated to determine the actual duration of the post-operative perturbation and subsequent validation of telemetry data. [less ▲]Detailed reference viewed: 212 (10 ULg)
Territorial and non-territorial spawning behaviour in the bream
Poncin, Pascal ; Philippart, Jean-Claude ;
in Journal of Fish Biology (1996), 49(4), 622-626
The spawning behaviour of bream Abramis brama was studied in 1993, in a harbour on the River Meuse, Belgium. Fish spaced from 22 to 27 April and from 11 to 14 May, when the water temperature rose to 14.5 ... [more ▼]
The spawning behaviour of bream Abramis brama was studied in 1993, in a harbour on the River Meuse, Belgium. Fish spaced from 22 to 27 April and from 11 to 14 May, when the water temperature rose to 14.5 degrees C. The reproductive behaviour of the bream was studied within a 15 m long part of the harbour using a video camera. Territorial males with tubercles (33-43 cm total length; > 5 years old) defended bank areas of diameter 80-150 cm which included spawning substratum, i.e. roots of alder and willow trees and aquatic plants. Water depth ranged from 25 to 50 cm. Non-territorial males without tubercles (24-33 cm; 3-4 years old), remained 2-4 m away from the bank. Aggressive behaviour between males was frequent and, occasionally, males with tubercles were unable to defend a territory. Mature females (25-43 cm; > 3 years old), coming from the deeper water of the surrounding area, were followed by non-territorial males before spawning in territories near the bank. (C) 1996 The Fisheries Society of the British Isles [less ▲]Detailed reference viewed: 36 (6 ULg)
Convention d’études pour le suivi scientifique de la réhabilitation du saumon atlantique dans le bassin de la Meuse
Philippart, Jean-Claude ; Rimbaud, Gilles ; et al
Report (1996)Detailed reference viewed: 19 (6 ULg)
A preliminary telemetry investigation on the obstacles to anadromous Salmonids migration in spawning streams of the Belgian Ardennes (river Meuse bassin)
Ovidio, Michaël ; ; et al
in Leclerc, Michel (Ed.) Proceedings of the Second IAHR Symposium on Habitat Hydraulics, Ecohydraulique 2000 (1996)
In the course of the 'Meuse Salmon 2000' programme aiming at the restoration of the Atlantic salmon Salmo salar and sea trout Salmo trutta in the River Meuse Basin, most large dams are progressively ... [more ▼]
In the course of the 'Meuse Salmon 2000' programme aiming at the restoration of the Atlantic salmon Salmo salar and sea trout Salmo trutta in the River Meuse Basin, most large dams are progressively equipped with fishways to restore the free circulation of spawners between the North Sea and the first major spawning streams, the River Ourthe and its tributaries. Spawners entering the River Ourthe would still be confronted to so-called minor obstacles, aiming at water regulation for tourism purposes but of which the actual impact on fish migration has never been investigated. In order to test for the actual free-circulation of salmonid spawners in the upper River Ourthe and to locate potential spawning grounds, a probe fish (489 mm FL male sea trout) was tagged with an intraperitoneally implanted radio-transmitter. From the 18th of ovember 1995 onwards, the trout was tracked in a part of the river (44 km upstream of the confluence) which was thought to be devoid of any major obstacle to fish migration. Three days after its release, the trout had migrated over 6 km up to a small weir (1.8 m high). During four consecutive days, the trout was consistently located downstream of the weir but no successful climbing was observed, reflecting the poor efficiency of the central fishpass under dry weather conditions during summer and autumn. The trout then settled in a deep run habitat, 150 m downstream of the weir and no upstream excursion was recorded until the first major rise of water level, four weeks later, even when the weir was opened for water regulation purposes. When the water level was maximum (24th of December), the trout moved upstream of the weir and migrated over 28 km during the next 72 hours up to a spot identified as a potential spawning redd from habitat features, and where it was consistently located till the 31st of December. These results, though most preliminary, clearly indicate that even minor obstacles may cause a substantial lag in trout migration of which the impact on spawning success remains to be determined. Since similar minor man-made obstacles are most frequent in the salmonid spawning streams of the Belgian Ardennes, it is thus uncertain that migratory trout having successfully climbed the major obstacles since the North Sea would find their way to the spawning redds. As a corollary, it is suggested that more detailed case studies should be undertaken, ideally via the use of telemetered probe-fish, in order to provide management policies that would represent a suitable compromise between users of water resources with apparently conflicting interests (water regulation, tourism, nature conservancy). [less ▲]Detailed reference viewed: 51 (8 ULg)
Histological and biometrical study of intraovarian oocytes in barbel (Barbus barbus) reared in captivity
Poncin, Pascal ; Thiry, Marc ; et al
in Folia Zoologica (1996), 45(Suppl. 1), 117-
In the present study, we investigated the histology and oocyte size variations in ovaries from barbel reared in captivity. We demonstrated that the size distribution of intraovarian oocytes is quadrimodal ... [more ▼]
In the present study, we investigated the histology and oocyte size variations in ovaries from barbel reared in captivity. We demonstrated that the size distribution of intraovarian oocytes is quadrimodal (including primary oocytes, oocytes with vacuoles, vitellogenetic oocytes and ova), Indicating that oocyte development can be found in the ovaries (some oocytes are in late vitellogenesis). The ovarian structure is discussed in realation to the repeated spawnings observed in captivity. [less ▲]Detailed reference viewed: 73 (5 ULg)
Occurrence and impact of Heteropolaria (Protozoa: Ciliophora), on intensively cultured perch Perca fluviatilis
; Mélard, Charles ; et al
in Annales Zoologici Fennici (1996), 33Detailed reference viewed: 21 (2 ULg)
Huit années (1988-1995) d’observations sur le fonctionnement des passes à poissons aux barrages d’Ampsin et de Lixhe en Meuse Liègeoise.
Philippart, Jean-Claude ; ; Ovidio, Michaël et al
Conference (1995, September 13)Detailed reference viewed: 18 (2 ULg)
A behavioural and histological assessment of post-tagging stress in brown trout Salmo trutta equipped with surgically implanted biotelemetry transmitters.
; ; Poncin, Pascal et al
Poster (1995)Detailed reference viewed: 7 (0 ULg)
Biologie de la reproduction de deux espèces de Chrysichthys (Siliuriforme, Bagridae) du Lac Nokoué et de la lagune de Porto-Novo au Bénin.
; Philippart, Jean-Claude ; Poncin, Pascal
in Journal of African Zoology = Revue de Zoologie Africaine (1995), 109(3), 213-224Detailed reference viewed: 89 (1 ULg)
Behavioural and endocrine study of Oreochromis aureus, with special reference to sex-reversed males. In Proceedings of the Fifth International Symposium on the Reproductive Physiology of Fish
Poncin, Pascal ; Ovidio, Michaël ; et al
in Goetz, F. W.; Thomas, P. (Eds.) Fish Symposium 95 (1995)Detailed reference viewed: 18 (5 ULg)
Production of high percentage male offspring with 17 a-ethynylestradiol sex reversed Oreochromis aureus: II. Comparative reproductive biology of females and F2 pseudofemales and large scale production of male progenies.
; Mélard, Charles ; Philippart, Jean-Claude
in Aquaculture (1995), 130Detailed reference viewed: 19 (5 ULg)
Pour que vive le barbeau... Bilan des recherches menées en Belgique pour restaurer les populations de barbeaux fluviatiles (Barbus barbus).
Poncin, Pascal ; Philippart, Jean-Claude
Poster (1994)Detailed reference viewed: 13 (4 ULg)
Comportement du Chrysichthys nigrodigitatus (Siluriformes, Bagridae) en conditions contrôlées : résultats préliminaires.
; Poncin, Pascal ; Philippart, Jean-Claude et al
Poster (1994)Detailed reference viewed: 52 (2 ULg)
Le comportement reproducteur des poissons de nos rivières. Le barbeau fluviatile Barbus barbus.
; Poncin, Pascal ; Philippart, Jean-Claude
Article for general public (1993)Detailed reference viewed: 71 (6 ULg)