References of "Belgian Journal of Zoology"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailSelective top-down control of epiphytic biomass by amphipods from Posidonia oceanica meadows: implications for ecosystem functioning
Michel, Loïc ULg; Dauby, Patrick ULg; Dupont, Alessandra et al

in Belgian Journal of Zoology (2015), 145(2), 83-93

Mediterranean Posidonia oceanica meadows shelter an important biomass and biodiversity of amphipod crustaceans that graze on epiphytes. However, their actual significance for ecosystem functional ... [more ▼]

Mediterranean Posidonia oceanica meadows shelter an important biomass and biodiversity of amphipod crustaceans that graze on epiphytes. However, their actual significance for ecosystem functional processes is hard to estimate, due to the lack of adequate data. Here, a field microcosm-based inclusion experiment was used to test if three of the dominant taxa of the amphipod community (Apherusa chiereghinii, Dexamine spiniventris and Gammarus spp.) could exert top-down control on seagrass leaf epiphytes. Influence of amphipod activity on nutrient availability for the host species was also investigated. All grazer taxa significantly reduced biomasses of erect macroalgae and erect sessile animals present on leaves. None of them consumed encrusting epiflora or epifauna. This selective top-down control could have important implications for the structure of the epiphytic community of P. oceanica leaves, which is one of the most diverse and abundant of all seagrass species. Grazing activity of all taxa caused higher N content of seagrass leaves, likely through amphipod excretion and/or sloppy feeding. Since P. oceanica meadows often grow in oligotrophic zones where plant growth can be nutrient-limited, this N enrichment could enhance seagrass production. Overall, the ecological interaction between P. oceanica and amphipods could be seen as a facultative mutualistic relationship. Our results suggest that amphipod mesograzers are key-elements in some of the functional processes regulating these complex and yet endangered ecosystems, which are essential components of Mediterranean coastal zones. [less ▲]

Detailed reference viewed: 40 (2 ULg)
Full Text
Peer Reviewed
See detailEarly colonization on Artificial Seagrass Units and on Posidonia oceanica (L.) Delile leaves
Pete, Dorothée ULg; Lepoint, Gilles ULg; Bouquegneau, Jean-Marie ULg et al

in Belgian Journal of Zoology (2015), 145(1), 59-68

Many epiphytes grow on Posidonia oceanica (L.) Delile leaves but early stages of that colonization are not well known. To study this early colonization without destroying the plant, Artificial Seagrass ... [more ▼]

Many epiphytes grow on Posidonia oceanica (L.) Delile leaves but early stages of that colonization are not well known. To study this early colonization without destroying the plant, Artificial Seagrass Units (ASUs) were utilised. The first nine days of colonization by macroscopic eukaryotic organisms on natural P. oceanica leaves and on ASUs were studied. The capability of those ASUs to mimic P. oceanica in the long term was also evaluated. Indeed, early colonists of a substrate can influence the settling of later ones by “priority effects”. Thus if the pioneer community is the same on both substrates, they will more likely be the same after a longer exposure time. On both substrates, colonization began by the settling of crustose-calcareous algae and foraminiferans. The number of organisms increased more quickly on ASUs than on natural leaves but Shannon-Wiener diversity index was higher for P. oceanica leaves. The low colonization rate on natural leaves may have been due to different microclimatic conditions on the two substrates and to a less developed biofilm than on ASUs. The high diversity observed on natural leaves was mainly related to the presence of bryozoan ancestrulae, which were absent on ASUs. Different microhabitats on each substrate (different algae morphotypes) can explain this difference. Thus, at such an early colonization stage, pioneer communities were different on the two substrates, suggesting that later communities would be different too. However, ASUs could be used in environmental perturbation studies instead of natural leaves, thanks to their high colonization rate. [less ▲]

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailBiodiversity and seasonal variations of zooneuston in the northwestern Mediterranean Sea
Collard, France ULg; Collignon, Amandine ULg; Hecq, Jean-Henri ULg et al

in Belgian Journal of Zoology (2015), 145(1), 40-48

Neuston includes animals and plants inhabiting the surface layer of the water column. The neustonic area is an accumulation zone for bacteria, organic molecules but also terrestrial debris. The surface ... [more ▼]

Neuston includes animals and plants inhabiting the surface layer of the water column. The neustonic area is an accumulation zone for bacteria, organic molecules but also terrestrial debris. The surface layer is also the air/water exchange region. Therefore, neustonic organisms are directly exposed to several constraints such as wind stress and turbulence. The present study aims to characterize the zooneuston in terms of abundance and biodiversity and to evaluate the impacts of wind stress on neustonic abundance. Zooneustonic and zooplanktonic (depth of 5 meters) samples were collected twice a month between 30th August 2011 and 10th July 2012 in Calvi Bay, Corsica. Zooneustonic biodiversity was high and, notably, twenty-eight copepod genera were identified. Among these copepods, several organisms, belonging to the Pontellidae family, were much more frequent in neuston than in underlying plankton and their abundance depended on wind direction. Taxon-specific trends in seasonal abundance variation were present. For example, individuals of the Acantharia Lithoptera spp. were found in summer whereas the Pontellidae Anomalocera patersoni appeared in winter. Overall, our data provide a first step towards a better knowledge of neuston community structure in the Mediterranean Sea. [less ▲]

Detailed reference viewed: 32 (5 ULg)
Full Text
Peer Reviewed
See detailAn ecological study of Electra posidoniae Gautier, 1954 (Cheilostomata, Anasca), a bryozoan epiphyte solely found on the seagrass Posidonia oceanica (L.) Delile, 1813
Lepoint, Gilles ULg; Mouchette, Olivier; Pelaprat, Corine et al

in Belgian Journal of Zoology (2014), 144(1), 51-63

The bryozoan Electra posidoniae Gautier is found solely on the leaves of the Neptune grass Posidonia oceanica (L.) Delile, dominating the leaf epifauna of this seagrass. Epiphytes of marine angiosperms ... [more ▼]

The bryozoan Electra posidoniae Gautier is found solely on the leaves of the Neptune grass Posidonia oceanica (L.) Delile, dominating the leaf epifauna of this seagrass. Epiphytes of marine angiosperms (or seagrasses) often play an important role in ecosystem functioning, for example as food web suppliers. As dysfunction of epiphytic compartment is often implied in human-induced seagrass decline, it is important to understand the dynamics and life traits of this community in pristine areas. This study involved the monthly assessment of colonization dynamics, biomass seasonality and diet composition through stable isotopes measurements of E. posidoniae at a depth of 10 m in the Revellata Bay (Corsica, Mediterranean Sea). Ancestrulae (i.e. colony founders) appeared towards the end of winter and were very selective in their settlement position along the P. oceanica leaves. A maximum of 100,000 colonies per square meter was recorded. E. posidoniae colonies dominated the epiphytic community biomass in early spring, and were over-covered by epiphytic algae in June. Food shortage could be also involved in this decrease. Although stable isotope ratios of C, N and S showed that this suspension feeder mainly relies on the water column productivity for its food, other food sources such as re-suspended epiphytic diatoms could be important in late spring (i.e. after the phytoplanktonic bloom). Additionally, a contribution of seagrass phytodetritus to the diet of this species cannot be excluded. The species was almost absent in winter, raising the question of its recruitment in spring. This study confirms the quantitative importance of this species in the seagrass meadow and explores its role in the relationship between the water column and this seagrass ecosystem. [less ▲]

Detailed reference viewed: 53 (14 ULg)
Full Text
Peer Reviewed
See detailKinematic analysis of swimming ontogeny in seabass (Dicentrarchus labrax).
Olivier, Damien ULg; Vandewalle, Nicolas ULg; Mauguit, Quentin et al

in Belgian Journal of Zoology (2013)

Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus ... [more ▼]

Swimming has been investigated in multiple species, but few studies consider the establishment of swimming through ontogeny. This study describes the establishment of cyclical swimming in Dicentrachus labrax, a marine fish from cold, temperate waters. The data were compared with results from previous studies on two subtropical freshwater catfish species (Clarias gariepinus and Corydoras aeneus). The three species have different modes of locomotion during their adult stage (anguilliform, subacarangiform and carangiform). The swimming of Dicentrarchus labrax was recorded with a high-speed video camera (500 fps) from 0 to 288 hours and from 960 to 2496 hours post-hatching. Three indices, i.e. coefficient of determination (r²), coefficient of variation (CV), and Strouhal number (St), were used to investigate the establishment and efficiency of swimming. Important differences in the timing of swimming establishment were observed between the seabass and the two catfish species. The two catfish species display a sine-shape swimming mode immediately or soon after hatching, and the efficiency of movement substantially improves during the first days of life. For seabass, however, establishment of swimming is slower during the same developmental period. These differences may be related to a faster developmental rate in the catfishes that allows them to swim rapidly in an intermediate regime flow and to develop the required morphology to establish efficient movements earlier. [less ▲]

Detailed reference viewed: 90 (64 ULg)
Full Text
Peer Reviewed
See detailWeb-building spiders and blood-feeding flies as prey of the notch-eared bat (Myotis emarginatus)
Kervyn, Thierry; Godin, Marie Céline; Jocqué, Rudy et al

in Belgian Journal of Zoology (2012), 142(1), 59-67

Conservation of the endangered notch-eared bat (M. emarginatus) requires a specific action plan based on precise ecological requirements of this species. The analysis of the diet of three colonies in ... [more ▼]

Conservation of the endangered notch-eared bat (M. emarginatus) requires a specific action plan based on precise ecological requirements of this species. The analysis of the diet of three colonies in southern Belgium revealed: (1) spatial and seasonal variations of the diet; (2) the consumption of web-building spiders (Araneus diadematus, A. triguttatus, Cyclosa conica, Enoplognatha sp., Larinioides patagiatus, Neriene emphana); (3) the predominance of blood-feeding dipterans in the diet (Stomoxys calcitrans and Musca autumnalis). Since the populations of these two ectoparasitic flies are sensitive to the use of antiparasitic drugs, these drugs should be used with caution by farmers and veterinarians in the vicinity of maternity colonies. [less ▲]

Detailed reference viewed: 128 (9 ULg)
Full Text
Peer Reviewed
See detailThe diet of the serotine bat: A Comparison between rural and urban environments
Kervyn, Thierry; Libois, Roland ULg

in Belgian Journal of Zoology (2008), 138(1), 41-49

The diet of four maternity colonies of serotine bats in Southern Belgium was investigated by analysing faecal pellets collected from beneath the roost throughout the activity season. Their diet is ... [more ▼]

The diet of four maternity colonies of serotine bats in Southern Belgium was investigated by analysing faecal pellets collected from beneath the roost throughout the activity season. Their diet is composed of Coleoptera Melolonthidae (Melolontha sp., Amphimallon sp., Rhizotrogus sp., Serica brunnea), Coleoptera Scarabaeidae (Aphodius sp., Geotrupes sp.), Coleoptera Carabidae, Diptera Tipulidae, Diptera Chironomidae, Lepidoptera, Hemiptera Pentatomidae, Hymenoptera Ichneumonoidea Ophionidae, Trichoptera and Arachnida. <br />The diet of an urban colony of serotine bats was broadly the same as the diets of three rural colonies. Though some qualitative and quantitative variations were observed between study sites, the main source of variation in the diet was the seasonal availability of potential prey. <br />The prominence of agriculture-dependant prey (chafers in mid summer and Aphodius beetles in late summer and autumn) was observed at all study sites. Consequently, dietary breadth and diversity is smaller during these periods. [less ▲]

Detailed reference viewed: 72 (9 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: 124 (27 ULg)
Full Text
Peer Reviewed
See detailObservations of the reduction of external gill filaments during larval development in Heterotis niloticus
Hermens, Michaël; Daffé, Mamina; Vandewalle, Pierre ULg

in Belgian Journal of Zoology (2007), 137(2), 247-249

Detailed reference viewed: 10 (1 ULg)
Full Text
Peer Reviewed
See detailDistribution patterns and indicator species of butterfly assemblages of wet meadows in southern Belgium
Sawchik, Javier; Dufrêne, Marc ULg; Lebrun, Philippe

in Belgian Journal of Zoology (2005), 135(1), 43-52

Focal species are a valuable tool for proposing and evaluating management practices for biodiversity conservation. Assemblages of indicator species could be used to cover a wide range of habitats. We ... [more ▼]

Focal species are a valuable tool for proposing and evaluating management practices for biodiversity conservation. Assemblages of indicator species could be used to cover a wide range of habitats. We identified the main patterns of variation in butterfly assemblages on a diverse set of wet meadows in southern Belgium. We used multivariate techniques to identify the butterfly assemblages and the species that characterize these habitats. Three main assemblages were identified, based principally on the dominance of five butterfly species : Brenthis ino, Closiana selene, Lycaena helle, Lycaena hippothoe and Proclossiana eunomia. These are indicator species of different habitats structured along a vegetation gradient. This gradient is partially determined by altitude and edaphic factors (base-richness, pH, fertility). We assume that focusing the conservation practices upon these species will promote the preservation of a wide range of organisms inhabiting the wet meadows. [less ▲]

Detailed reference viewed: 74 (5 ULg)
Full Text
Peer Reviewed
See detailBiogeographical Observations On Four Scolytids (Coleoptera, Scolytidae) And One Lymexylonid (Coleoptera, Lymexylonidae) In Wallonia (Southern Belgium)
Henin, Jm.; Huart, O.; Rondeux, Jacques ULg

in Belgian Journal of Zoology (2003), 133(2), 175-180

Following a very sudden, early and deep frost at the end of autumn 1998, the availability of weakened trees (mainly beech trees) reached very high levels in Southern Belgium in the spring of 1999 ... [more ▼]

Following a very sudden, early and deep frost at the end of autumn 1998, the availability of weakened trees (mainly beech trees) reached very high levels in Southern Belgium in the spring of 1999. Consequently, the ambrosia beetles Trypodendron domesticum L. and T. signatum (Fabricius) (Coleoptera, Scolytidae) initiated outbreaks and, in 2000 and 2001, they heavily contributed to the depreciation of nearly 1,600,000 m3 of stem volume (to upper limit girth of 22 cm) in the natural regions of “Ardenne” and “Belgian Lorraine”. Because of the lack of biogeographical data on both insects, of their conspicuous aggressiveness towards apparently healthy trees and of the economic importance of the beech wood chain in Belgium, a large-scale survey was undertaken in 2001, in order to outline the range of both ambrosia beetles in Wallonia. To this effect, a network of 172 traps baited with ethanol was set up, attempting to cover the Walloon beech forest as representatively as possible. Two other scolytids and one lymexylonid were also frequently caught, which made it possible to outline their regional distribution too. Although the damage was limited to the Ardenne and Belgian Lorraine, T. domesticum and T. signatum are widespread throughout Wallonia. We discuss these results, their long-term validity, the secondary pest status of these insects and the need for a permanent monitoring of the major forest pest species and diseases. [less ▲]

Detailed reference viewed: 30 (6 ULg)
Full Text
Peer Reviewed
See detailTrophic habits and aquatic microhabitat use in gilled immature, paedomorphic and metamorphic Alpine newts (Triturus alpestris apuanus) in a pond in central Italy
Denoël, Mathieu ULg; Andreone, F.

in Belgian Journal of Zoology (2003), 133(2), 95-102

Current evolutionary models suggest that the presence of heterogeneous habitats favours the evolution of polymorphisms. In such cases, alternative phenotypes can coexist because they use different ... [more ▼]

Current evolutionary models suggest that the presence of heterogeneous habitats favours the evolution of polymorphisms. In such cases, alternative phenotypes can coexist because they use different resources. Facultative paedomorphosis is a heterochronic polymorphism in which a morph - the paedomorph - retains larval traits during the adult stage while the other morph - the metamorph - is fully metamorphosed. The aim of this study was to determine the microhabitat use and the diet of Alpine newt paedomorphs, metamorphs and immatures (Triturus alpestris apuanus) coexisting in a small pond in Tuscany, central Italy, i.e. in a habitat where dimorphism is not expected. Although the two adult morphs do not use exactly the same resources, resource partitioning was weaker than in deep Alpine lakes. Nevertheless, the diet of immature gilled newts (larvae) differed from that of adults (metamorphs and paedomorphs). While the larvae eat a large number of planktonic organisms, the adults focus on insect larvae and newt eggs. The differences in resource use favour the coexistence of aquatic juveniles and adults. In the studied pond, facultative paedomorphosis was previously shown to be favoured by a precocious maturity of the paedomorphs. This study shows that the coexistence of paedomorphs and metamorphs may also be supported by some dietary and spatial segregation, although any advantages gained by this pattern are rather limited in the adult stage. [less ▲]

Detailed reference viewed: 280 (18 ULg)
Full Text
Peer Reviewed
See detailParticularities of the bucco-pharyngeal apparatus in Zenarchopterus kampeni (Pisces : Hemiramphidae) and their probable significance in feeding
Vandewalle, Pierre ULg; Lambert, Vincianne; Parmentier, Eric ULg

in Belgian Journal of Zoology (2002), 132(2), 125-132

The present study shows several new anatomical particularities of the buccal and pharyngeal parts of the halfbeak Zenarchopterus kampeni. The upper buccal jaw consists of premaxillaries and maxillaries ... [more ▼]

The present study shows several new anatomical particularities of the buccal and pharyngeal parts of the halfbeak Zenarchopterus kampeni. The upper buccal jaw consists of premaxillaries and maxillaries tightly joined by ligaments. A 10degrees lowering of the mandible leads to a 30degrees elevation of the upper jaw. The adductor mandibulae is reduced to bundles A(2) and Aomega. As in the Labridae, the lower pharyngeal jaw articulates with the scapular girdle. The upper pharyngeal jaw consists of distinct second pharyngobranchials followed by the third pharyngobranchials fused into a powerful posterior component. This part fits into and slides along a longitudinal ventral gutter of the neuroranium, thanks not only to the dorsal retractor muscles but also to specific retractors of the second pharyngobranchials. The power and dentition of the pharyngeal parts contrasts with the fragility of the buccal elements. [less ▲]

Detailed reference viewed: 169 (2 ULg)
Full Text
Peer Reviewed
See detailConservation of the lesser horseshoe bat (Rhinolophus hipposideros Bechstein, 1800) (Mammalia : Chiroptera) in Belgium. A case study of feeding habitat requirements
Motte, G.; Libois, Roland ULg

in Belgian Journal of Zoology (2002), 132(1), 49-54

The aim of this study was to determine the habitat use of the last important Belgian colony of Rhinolophus hipposideros, Bechstein, 1800, one of the most endangered bat species in Europe. During 71 ... [more ▼]

The aim of this study was to determine the habitat use of the last important Belgian colony of Rhinolophus hipposideros, Bechstein, 1800, one of the most endangered bat species in Europe. During 71 evenings from April to August 1998, ultrasound detection was performed and, in late August, a female horseshoe bat was caught and fitted with a radio transmitter. The results showed that hedgerows and woodlands with bushes and coppice are key foraging habitats. They also highlight the importance of the presence of a network of wooded elements connecting the maternity roost with the foraging areas. To assure long-term protection of this colony, strong habitat conservation measures should be taken in a radius of up to 1-2 km around the roost. [less ▲]

Detailed reference viewed: 231 (2 ULg)
Full Text
Peer Reviewed
See detailThe karyotype of the Formentera island garden dormouse, Eliomys quercinus ophiusae
Ramalhinho, Graça; Libois, Roland ULg

in Belgian Journal of Zoology (2001), 131(1), 83-85

Detailed reference viewed: 19 (2 ULg)
Full Text
Peer Reviewed
See detailIs the woodmouse (Apodemus sylvaticus) of sicily a distinct species?
Michaux, Johan ULg; Sara, Maurizio; Libois, Roland ULg et al

in Belgian Journal of Zoology (1998), 128(2), 211-214

[No abstract available]

Detailed reference viewed: 49 (7 ULg)
Full Text
Peer Reviewed
See detailThe 37 LRP/P40 polypeptide: a multifunctional pleiotropic molecule involved in tumorigenesis and metastasis - A review
Clausse, Nathalie; Jackers, Pascale ULg; Castronovo, Vincenzo ULg

in Belgian Journal of Zoology (1997), 127(issue 1), 3-11

Detailed reference viewed: 72 (51 ULg)
Full Text
Peer Reviewed
See detailMicroscopic observation of the retinal photoreceptor layer of the common barbel (Teleostei: Cyprinidae)
Compère, Philippe ULg; Poncin, Pascal ULg

in Belgian Journal Of Zoology (1996), 126(1), 49-56

Light and electron microscopic observations show that cones-belonging to four types are present in the retina of the common barbel Barbus barbus (L.): short single cones, long single cones, twin cones ... [more ▼]

Light and electron microscopic observations show that cones-belonging to four types are present in the retina of the common barbel Barbus barbus (L.): short single cones, long single cones, twin cones, and unequal double cones. They do not exhibit any particular arrangement. Estimates of cone density suggest that the common barbel has multichromatic vision but of low acuity and that no difference exists between the lower and the upper parts of the retina. Both cone density (approximately 3000 units/mm(2)) and the proportion of double cones to single cones (approximately 1:3) are low. The view that the barbel has an inferior colour vision is in good agreement with the fact that this species is active mainly at twilight, but with diurnal activity during spawning. [less ▲]

Detailed reference viewed: 31 (5 ULg)