References of "Jeuniaux, Charles"
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See detailChapter 3, The Integument : Morphology and Biochemistry
Compère, Philippe ULg; Jeuniaux, Charles ULg; Goffinet, Gerhard ULg

in Forest, J.; von Vaupel Klein, J. C.; Schram, F. R. (Eds.) The Crustacea revised and updated from the Traité de Zoologie Vol 1 (2004)

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See detailDistribution and activity of chitinolytic enzymes in the digestive tract of birds and mammals
Jeuniaux, Charles ULg; Cornelius, C.

Scientific conference (1997, April)

The extraction and purification of chitinolytic enzymes devoid of any lysozymic activity, taken from the gastric mucosa of mamals, indicated that these enzymes are true chitinases, rather than lysozymes ... [more ▼]

The extraction and purification of chitinolytic enzymes devoid of any lysozymic activity, taken from the gastric mucosa of mamals, indicated that these enzymes are true chitinases, rather than lysozymes with chitinolytic activity. A close relationship was found between chitinase secretions in the digestive tract and the nature of the normal diet of the species considered. Changing the diet of an animal (mouse, rat, hamster, guinea pig) for a few weeks did not modify its ability or inability to secrete chitinase. In the digestive tract of birds, chitinase is secreted only by the gtastric mucosa. All the more or less insectivorous birds so far studied, including chickens, do secrete gastric chitinases. No chitinase secretion was dected in the pigeon or the parrot. In mammals, gastric chitinases were found in omnivorous and insectivorous species belonging to the orders Insectivora, Chiroptera, Carnivora, Rodenta and primates. in the pig, chitinases are secreted by the gastric mucosa and by the pancreas. The digestibility of chitin in both a purified and a natural form was estimated in feeding experiments with mice, Japanese nightingales and chickens. From 19% to 58% chitin was digested by mice and chickens that were fed a diet containing pure chitin, and by Japanese nightingales that were fed mealworm larvae. [less ▲]

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See detailConfirmation of the presence of chitin in fin cuticles of some blenniidae (Teleostei) by enzymatic and cytochemical methods
Jeuniaux, Charles ULg; Compère, Philippe ULg; Toussaint, Claudine et al

in Domard, Alain; Jeuniaux, Charles; Muzzarelli, Ricardo (Eds.) et al Advances in chitin sciences, volume I (1996)

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See detailQuantitative estimation of chitin and proteins in the cuticle of five species of Priapulida
Saldarriaga, Juan F.; Voss-Foucart, Marie-Françoise; Compère, Philippe ULg et al

in Sarsia. North Atlantic Marine Science (1995), 80

The biochemical composition ofthe cuticle of 5 species of Priapulida was tested using a specific enzymatic method for the determination of chitin, and a lectin-labelling technique for its ultrastructural ... [more ▼]

The biochemical composition ofthe cuticle of 5 species of Priapulida was tested using a specific enzymatic method for the determination of chitin, and a lectin-labelling technique for its ultrastructural location. The integument of all species tested contains 4–15 % chitin and 9–85 % protein. Chitin could be located in both layers of the priapulid cuticle, even though their ultrastructural morphology differs. The results of this work suggest a close relationship between the Priapulida and the Kinorhyncha, the only other group of Aschelminths known to have a chitinous cuticle. [less ▲]

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See detailEfficacité du piège à fosse pour la collecte d' Hypnoidus riparius (Fabricius) (Coleoptera, Elateridae)
Jeuniaux, Charles ULg; Dufrêne, Marc ULg

in Bulletin et Annales de la Société Royale Belge d’Entomologie = Bulletin en Annalen van de Koninklijke Belgische Vereniging voor Entomologie (1995), 131

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See detailLa production de chitine par les crustacés dans les écosystèmes marins
Jeuniaux, Charles ULg; Voss-Foucart, Marie-Françoise; Bussers, Jean-Claude

in Aquatic Living Resources (1993), 6

Chitin is synthesized by numerous animal species, either unicellular organisms or metazoans, belonging mainly to zoological groups of the Coelomate Spiralia lineage. However, the produced chitin in marine ... [more ▼]

Chitin is synthesized by numerous animal species, either unicellular organisms or metazoans, belonging mainly to zoological groups of the Coelomate Spiralia lineage. However, the produced chitin in marine ecosystems is principally by crustaceans. A comparative study of analytical data so far available allowed calculation of chitin biomass and chitin production values in some types of marine ecosystems, and thus estimation of the quantitative importance of chitin in the biogeochemical cycles of carbon and nitrogen. The main data so far available concerns mediterranean plankton in Calvi bay (Corsica), arctic and antartic krill, lobster population on South African coasts, and infralittoral benthic communities growing on rocky substrates on Corsica coasts. In all these cases, chitin production was estimated roughly at 1g per year and per square meter of rocky substrate or sea surface. Taking into account these production values and the relative extent of the main marine ecosystems over the world, the totalproduction of chitin due to marine crustaceans was estimated at about 2.3 billion metric tons per year. [less ▲]

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See detailQuantitative determination of "free" and "bound" chitin
Jeuniaux, Charles ULg

in BeMiller, James N.; Whistler, Roy L. (Eds.) Methods in carbohydrate chemistry. Volume 9 : Lipopolysaccharides, separation and analysis, glycosylated polymers (1993)

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See detailExpansion ou régression des aires de distribution de quelques espèces de Coléoptères Elateridae d'Europe occidentale
Jeuniaux, Charles ULg

in Mém. soc. r. belge ent. (1992), 35

L'examen des matériaux de collection accumulés depuis 150 ans et le traitement cartographique et statistique des données permettent de reconnaître certaines tendances expansives ou régressives des aires ... [more ▼]

L'examen des matériaux de collection accumulés depuis 150 ans et le traitement cartographique et statistique des données permettent de reconnaître certaines tendances expansives ou régressives des aires de distribution des Elatérides en Europe occidentale; Dans certains cas, ces tendances peuvent être attribuées à l'effet de l'altération des conditions écologiques, d'origine anthropiques, ou à celui de modifications méso- ou macroclimatiques. [less ▲]

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See detailChitin biodegradation in marine environments : an experimental approach
Poulicek, Mathieu ULg; Jeuniaux, Charles ULg

in Biochemical systematics and ecology (1991), 19(5), 385-394

Chitin biomasses and production in marine environments are quite high. Planktonic biocenoses arte the main producers and one should expect that sediments, mainly organoclastic ones, will constitute some ... [more ▼]

Chitin biomasses and production in marine environments are quite high. Planktonic biocenoses arte the main producers and one should expect that sediments, mainly organoclastic ones, will constitute some kind of reserve compartment for the biogeochemical cycle of this polymer. In fact, this is not the case. The low chitin biomass in most marine sediments can only be explained if chitin is weathered at the same rate as it is produced. In order to test this hypothesis, we developed an experimental approach to chitin biodegradation in marine environments. In open water conditions, zooplanktonic remains are first degraded by autolytic processes making most organic compounds readily susceptible for further hydrolysis by extrinsic decomposers. Different populations (with high densities and various hydrolytic potentials) follow each other. The sequence of hydrolyc activities optimizes the recycling of most detritic compounds including nearly 90% of the chitin produced. At sediment-water interface, the remaining material appears to be pulvirized and incorporated into the aerobic sedimentary layers while the decomposer community changes once again. Sediment chitinoclasts are opportunistic and densities react quickly to chitin input. In sediments, oxic and anoxic, chitin appears essentially present in the form of chitinoproteic matrices inside mineralized skeletons. A rich population of microborers develops on these matrices by secreting extracellular hydrolases. Densities of microborers of 250-450 * 10 3 cm-2 are currently encountered. Anaerobic decomposers are more adapted to refractory compounds than aerobic ones. This leads to a nearly complete mineralization of the chitinoproteic matrices embedded in the biotic sedimentary layers (more than 90% of the chitin weathered within less than two years). [less ▲]

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See detailInventaire des Coléoptères Elatérides de la "Petite Suisse Luxembourgeoise" (Grand-Duché de Luxembourg) et particularités biogéographiques et écologiques de ce site
Jeuniaux, Charles ULg

in Van Goethem, Jackie L.; Grootaert, Patrick (Eds.) Faunal inventories of sites for cartography and nature conservation (1991)

Thirty-eight click-beetle species (Coleoptera Elateridae) have been observed in the "Petite Suisse Luxembourgeoise", oriental area of the Gutland enclosed in the main loop of the Sûre River above ... [more ▼]

Thirty-eight click-beetle species (Coleoptera Elateridae) have been observed in the "Petite Suisse Luxembourgeoise", oriental area of the Gutland enclosed in the main loop of the Sûre River above Echternach. Besides typically sylvicolous species, this fauna is original by the presence of several psammophilous species, some of which showing however atlantic distribution in Western Europe. These faunistic characteristics stand in contrast with those pf neighbouring areas, namely Oestling in Luxembourg, Ardenne in Belgium, and Eifel in Germany. [less ▲]

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See detailAtlas des insectes de Belgique (et des régions limitrophes) Coleoptera Elateridae : troisième partie
Jeuniaux, Charles ULg

in Notes Fauniques de Gembloux (1991), 24

The distribution of the species of four different subfamilies of Elateridae in Belgian and Luxemburg is analysed. Elater ferrugineus, delonging to the subfamily Elaterinae, is a saproxicolous scarce ... [more ▼]

The distribution of the species of four different subfamilies of Elateridae in Belgian and Luxemburg is analysed. Elater ferrugineus, delonging to the subfamily Elaterinae, is a saproxicolous scarce species. Among Denticollinae, Denticollis linearis is ubiquitous, but D. rubens is strictly localized in south Belgium and in Luxemburg. There are 12 different species belonging to Agriotinae, among which Agriotes gallicus and Agriotes ustulatus are thermophilous species of meridional origin, while others (Ectinus aterrimus, Sericus brunneus) are psammophilous species living in sandy biotopes. The subfamily Adrastinae includes 6 species, two of which inhabit plains below 300 meters (Synaptus filiformis and Adrastus rachifer) and one is a thermophilous species of meridional origin (Adrastus limbatus). [less ▲]

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See detailChitin biomass and production in the marine environment
Jeuniaux, Charles ULg; Voss-Foucart, Marie Françoise

in Biochemical Systematics & Ecology (1991), 19(5), 347-356

The total production nof chitin has been tentatively calculated on the basis of original analytical data on chitin in zooplankton and in benthic communities growing on experimental substrates studied in ... [more ▼]

The total production nof chitin has been tentatively calculated on the basis of original analytical data on chitin in zooplankton and in benthic communities growing on experimental substrates studied in the Mediterranean Sea, together with data in the literature dealing with total and exuviae production by krill and by some large crustacean species. It appears that crustaceans are the main chitin producers both in planktonic and benthic ecosystems, and that mean total production of chitin in the whole marine biocycle is at least of 2,3 billion metric tons per year. [less ▲]

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See detailChitin in biogeochemical cycles : Abstract 202
Jeuniaux, Charles ULg; Seki, H.

Conference (1990, August)

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See detailEtude quantitative préléminaire de la composition chimique des communautés pionnières colonisant divers types de plastiques en Méditerrannée
Voss-Foucart, M.-F.; Bussers, J.-C.; Poizat, R. et al

in Rapp. Comm. Int. Mer Medit. (1990), 32(1), -25

Etude des peuplements pionniers colonisant des substrats vierges, notamment en plastique, en Méditerranée.

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See detailProduction, extraction et utilisation technologique de la chitine à partir de communautés marines
Jeuniaux, Charles ULg; Thomé, Jean-Pierre

in Océanis (1990), 16(5), 375-382

Chitin production by marine communities in the Mediterranean Sea was studied in Calvi Bay (Corsica). Its mean value amounted to 1 g m-2 year-1 in zooplankton as well as in benthic pioneering communities ... [more ▼]

Chitin production by marine communities in the Mediterranean Sea was studied in Calvi Bay (Corsica). Its mean value amounted to 1 g m-2 year-1 in zooplankton as well as in benthic pioneering communities growing on rocky substrates at a depth of 18 m. Crustaceans are the main chitin producers. Chitin from cuticles can easily be extracted and chemically deacetylated into chitosan. Particular attention was paid in our laboratory to its the treatment of PCB-polluted natural surface water. [less ▲]

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See detailObservations récentes de deux espèces du genre Stenagostus (Coleoptera, Elateridae) en Belgique
Jeuniaux, Charles ULg

in Bulletin et Annales de la Société Royale Belge d'Entomologie = Bulletin en Annalen van de Koninklijke Belgische Vereniging voor Entomologie (1990), 126

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See detailAtlas des insectes de Belgique (et des régions limitrophes) Coleoptera Elateridae : deuxième partie
Jeuniaux, Charles ULg

in Notes Fauniques de Gembloux (1990), 22

La répartition en Belgique et au Grand-Duché de Luxembourg a été établie pour 54 espèces d'Elatérides appartenant à 10 sous-familles différentes : Agrypninae, Ampedinae, Conoferinae, Physorhininae ... [more ▼]

La répartition en Belgique et au Grand-Duché de Luxembourg a été établie pour 54 espèces d'Elatérides appartenant à 10 sous-familles différentes : Agrypninae, Ampedinae, Conoferinae, Physorhininae, Hypnoïdinae, Negastriinae, Cardiophorinae, Melanotinae, Pomachiliinae et Athoïnae, sur base de matériaux de collection accumulés depuis 1850. Sur ces 54 espèces, treize montrent une distribution en Belgique plus ou moins ubiquiste et vingt sont rares, très localisées ou en voie de disparition. Onze espèces sont localisées dans le sud de la Belgique et au Luxembourg (Ampedus cinnabarinus, A. elegantulus, A. nigroflavus, Cardiophorus rufipes, Idolus picipennis, Cidnopus parvulus, Limonius aeneoniger, Hypnoïdus riparius, Zorochrus dermestoïdes, Z. flavipes et Quasimus minutissimus) tandis que quatre espèces sont au contraire principalement localisées dans le nord de la Belgique (Ampedus sanguinolentus, Cardiophorus ruficollis, Melanotus niger, Negastrius pulchellus). Deux espèces semblent en voie d'expansion : l'une probablement d'origine orientale (Ampedus sanguineus), l'autre probablement d'origine atlantique (Athous difformis). Enfin, la distribution de trois espèces de Cardiophorinae semble liée à la présence de biotopes sablonneux. [less ▲]

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