molecular and physiological study of the artificial maturation process in european eel males: from brain to testis.european eel males can be artificially matured (1.5iu hcg/g fish), but the regulatory mechanisms of their reproductive development are practically unknown. spermatogenic stages (s1-s6), biometric characters [eye index (ei), gonadosomatic index (gsi), hepatosomatic index (hsi)] and sperm quality parameters (motility, viability and head spermatozoa morphometry) were analysed. moreover, the present study evaluated the expression of gnrhs (mammal and chicken ii gonadotropin release hormone i) and go ...201019699741
experimental studies on the development of contracaecum rudolphii (nematoda: anisakidae) in copepod and fish paratenic hosts.the larval development of the nematode contracaecum rudolphii (rudolphi, 1819), a common parasite of the proventriculus of cormorants, was experimentally studied. within the eggs cultivated in freshwater under laboratory temperatures of 20-22 degrees c, the developing larva undergoes two moults on days 4-5, attaining the third larval stage. most of the ensheathed third-stage larvae, 291-457 microm long, hatch spontaneously from egg shells on days 5-6. experiments have indicated that hatched ensh ...200919827362
massive encapsulation of larval anguillicoloides crassus in the intestinal wall of japanese eels.abstract:200919832983
genetic variability is unrelated to growth and parasite infestation in natural populations of the european eel (anguilla anguilla).positive correlations between individual genetic heterozygosity and fitness-related traits (hfcs) have been observed in organisms as diverse as plants, marine bivalves, fish or mammals. hfcs are not universal and the strength and stability of hfcs seem to be variable across species, populations and ages. we analysed the relationship between individual genetic variability and two different estimators of fitness in natural samples of european eel, growth rate (using back-calculated length-at-age 1 ...200919840264
gross and microscopic pathological changes associated with parasitic infection in european eel (anguilla anguilla, linnaeus 1758).the gross pathological and histopathological changes associated with parasitic infection in the european eel (anguilla anguilla linnaeus, 1758) was investigated. a total of 65 eels collected from three sampling localities in eastern delta, egypt were examined over the period of january-may 2008. the fish were subjected to standard procedures for parasitological and pathological examinations. overall, 22 (33.8%) of the 65 fish examined were found to have parasitic infections. the eels harbored a ...201019953271
polychlorinated biphenyls and organochlorine pesticides in european eel (anguilla anguilla) from the garigliano river (campania region, italy).measuring organochlorine compounds in muscle tissue of european eels from the garigliano river in campania (italy), overall pcbs emerged as the most abundant pollutants, followed by ddts, dieldrin and hcb. target pcbs, iupac nos. 118, 138, 153 and 180, were the dominant congeners accounting for 64.2% of total pcbs. among ocps, p,p'-dde was detected in all eels, always with higher concentration levels than other ocps; p,p'-ddt was frequently detected, about 93.3% of the sample. the high and stati ...201020022354
temporal analysis of electroretinographic responses in fishes with rod-dominated and mixed rod-cone retina.photoreceptor content of fish retinas could be accessed by comparative electroretinographic (erg) studies using flickering light stimuli that could separate rod-mediated vision where critical flicker frequency (cff, frequency when the eye loses its ability to resolve individual light pulses) is usually less than 15 hz from cone-mediated vision. four fish species inhabiting different photic environments (small-spotted dogfish shark--scyliorhinus canicula, eel--anguilla anguilla, painted comber--s ...200920037193
changes in gene expression in european eels (anguilla anguilla) induced by infection with swim bladder nematodes (anguillicola crassus).the european eel, anguilla anguilla, is considered an endangered species that is under pressure for many reasons. among others, the introduced parasite anguillicola crassus is thought to play an important role in the decline of eel populations. these nematodes have been shown to negatively affect many fitness-related traits in eels, e.g., growth, osmoregulation, and stress tolerance. nevertheless, there has been little work on the way in which the host-parasite interaction influences the molecul ...200920049987
chemical contaminants in fish species from rivers in the north of luxembourg: potential impact on the eurasian otter (lutra lutra).contamination levels of pcbs, and of the heavy metals cadmium (cd), lead (pb) and mercury (hg) were analyzed in four fish species from seven rivers in the north of luxembourg. during august and september 2007, 85 samples of fish were collected belonging to four species: the stone loach (barbatula barbatula, n=12 pools), the chub (squalius cephalus, n=36), the barbel (barbus barbus, n=23) and eel (anguilla anguilla, n=14). the concentration of seven indicator pcbs ( summation operator(7)pcbs) rea ...201020060148
comparative study about the effects of pollution on glass and yellow eels (anguilla anguilla) from the estuaries of minho, lima and douro rivers (nw portugal).the health status of eels (anguilla anguilla) developing in three estuaries of the nw portuguese coast with different types and levels of pollution was compared in relation to morphometric parameters, fulton condition index (f index) and several biomarkers. relatively to the reference population, glass eels from the lima estuary had lower weight and length, cholinesterase (che) and lactate dehydrogenase (ldh) inhibition, and lower levels of some anti-oxidant parameters, while yellow eels also sh ...201020116101
[non-indigenous and non-specific parasitic nematodes--the background and the consequences].introduction of the host is the main reason behind introduction of the parasite, e. g., nematodes. the introduction of the japanese eel (anguilla japonica) in europe in the 1980s resulted in expansion of the swimbladder nematode anguillicola crassus which soon invaded not only populations of the european eel (a. anguilla), but also other local fish. the raccoon (procyon lotor) is native to north america. it is the specific host of strongyloides procyonis and baylisascaris procyonis. more than 90 ...200920209803
simultaneous use of strontium:calcium and barium:calcium ratios in otoliths as markers of habitat: application to the european eel (anguilla anguilla) in the adour basin, south west and ba:ca ratios in water from the adour estuary show a clear relationship with the salinity of the surrounding water for salinities <20, while ratios are almost constant above this level of salinity. a positive relationship was observed for the sr:ca ratio, whereas it was inverse for the ba:ca ratio. these two elemental ratios were measured in the otoliths of the european eels (anguilla anguilla l.) using femtosecond laser ablation linked to an icp-ms (fs-la-icp-ms). there was a direct re ...201020338633
natural, social, economical and political influences on fisheries: a review of the transitional area of the polish waters of the vistula lagoon.a 60 year (1948-2007) dataset gathered by polish researchers working on the vistula lagoon fish assemblages and fisheries has shown this stressed transitional environment to be always been dominated by a few highly abundant fish species. during this period, the surrounding countries poland and russia (kaliningrad) were transformed from centrally-planned economies with fixed prices to free market systems. the organization of the fishery evolved from one in which the majority of the fishing effort ...201020359718
epidemiology and pathology of anguillicoloides crassus in european eel anguilla anguilla from the tagus estuary (portugal).infection of the european eel anguilla anguilla by the swimbladder nematode anguillicoloides crassus was investigated for the first time at 5 sampling sites in the tagus estuary (portugal). a total of 332 yellow eels were examined, revealing a prevalence of 56% and a mean intensity of 3.2 lumen worms per swimbladder. the effect of the host's sex and size on parasitism descriptors was studied. only total length (tl) was considered a significant determinant, with larger eels harbouring a higher nu ...201020377012
spatial variations in the levels and isomeric patterns of pbdes and hbcds in the european eel in flanders.pooled yellow eel (anguilla anguilla l.) samples, consisting of 3-10 eels, from 50 locations collected in the period 2000-2006 were used to assess the pollution with pbdes and hbcds in flemish waters (belgium). results from this monitoring network are presented and the spatial aspect throughout flanders is included, linking pop levels to the industrial characteristics of the different sampling locations. the following pbde congeners were measured using gc/ms: 28, 47, 49, 66, 85, 99, 100, 153, 15 ...201020399500
organochlorine pollutants in european eel (anguilla anguilla l.) from poland.the purpose of the current paper is to report the levels of oc pesticides ([summation operator]hchs, hcb, [summation operator]ddts), marker pcbs, pcdd/fs, and dl-pcbs in the muscle tissue of european eel, anguilla anguilla (l.), collected in the vistula and szczecin lagoons (poland), and in the local market. the results obtained were evaluated according to maximum limits adopted by eu, and some national legislatures. the intake of organochlorine contaminants from the consumption of eel from poli ...201020447675
identification of fucosylated glycoconjugates in xenopus laevis testis by lectin histochemistry.glycoconjugates play roles in many physiological and pathological processes. previous works have shown important functions mediated by glycans in spermatogenesis, and the carbohydrate composition of testis has been studied by several approaches, including lectin-histochemical methods. however, the testis of xenopus laevis, an animal model extensively employed in biochemical, cell and developmental research, has not yet been analysed. the aim of this work was to carry out a histochemical study of ...201020617442
genetic signatures in an invasive parasite of anguilla anguilla correlate with differential stock this article, it is shown that available genetic tools for the omnipresent parasite anguillicoloides crassus in european eels anguilla anguilla are sensitive to different immigration rates into local a. anguilla stocks for two separated river systems. relying on four highly polymorphic microsatellite markers, it was inferred that under natural recruitment, nematode samples meet hardy-weinberg expectations for a single panmictic population, while genetic signals show signs for a strong wahlund ...201020646147
effects of crude oil and oil fractions on the liver p450-dependent monooxygenase activities and antioxidant defence system of different freshwater fish species.the effects of crude oil (szeged-algyo, hungary) and oil fractions (f1: rich in aromatics; f2 fraction: free from aromatics) were investigated on liver cyp1a isoenzymes and antioxidant defence system following their i.p. injection into different freshwater fish species: carp (cyprinus carpio l.), silver carp (hyphothalmichtys molitrix v.), and european eel (anquilla anquilla). a dose of 2 ml kg -1 crude oil enhanced erod activity 8-fold in carp and only 5-fold in eel after 3 days. oil fraction f ...201020724273
effects of the swimbladder parasite anguillicola crassus on the migration of european silver eels anguilla anguilla in the baltic a mark-recapture study in 2006, migrating european anguilla anguilla silver eels were caught, tagged and released in the baltic sea and recaptures in commercial pound nets examined for possible effects on migration of infection with the swimbladder parasite anguillicola crassus. the overall recapture rate was 36%. the prevalence of infection was lowest at the northernmost sampling site. there were no significant differences between infected and uninfected a. anguilla in condition indices, bod ...200920735694
occurrence of priority hazardous pahs in water, suspended particulate matter, sediment and common eels (anguilla anguilla) in the urban stretch of the river tiber (italy).this study investigated the occurrence of polycyclic aromatic hydrocarbons (pahs) in water, suspended particulate matter (spm), bed sediment and common eels (anguilla anguilla) in the urban stretch of the river tiber (italy). the selected pahs, fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(g,h,i)perylene, indeno(1,2,3-cd)pyrene, belong to the ec priority list of dangerous substances. spm was found to be the most polluted compartment, with values ranging from 166 ...201020932548
the catecholamine release-inhibitory peptide catestatin (chromogranin a344-363) modulates myocardial function in fish.catestatin (cst), the 21-amino acid, cationic and hydrophobic peptide proteolytically derived from the ubiquitous chromogranin a (cga), is an endogenous inhibitor of catecholamine release, a potent vasodilator in vivo and an anti-hypertensive agent in mammals, including humans. recently, we discovered that cst also functions as an important negative modulator of heart performance in frog and rat. to gain an evolutionary perspective on cst cardiotropism in fish, we analysed the influence of bovin ...201020952611
what can we learn from monitoring pcbs in the european eel? a belgian experience.between 2000 and 2007 pooled muscle tissue samples of the european eel (anguilla anguilla) from 48 sites in flanders (belgium) were analysed for 30 polychlorinated biphenyl (pcb) congeners. there was a large variation between individual sites (range 11-7752 ng/g wet weight (ww) for the sum of the ices 7 pcbs), eels from the river meuse basin (mean 1545 ng/g ww) being considerably more polluted than those from the river scheldt (615) and ijzer (61) basins. overall, pcb 153, pcb 138 and pcb 180 we ...201121075450
the in vitro effect of bovine lactoferrin on the activity of organ leukocytes in rainbow trout (oncorhynchus mykiss), european eel (anguilla anguilla) and wels catfish (silurus glanis).lactoferrin (lf) is a glycoprotein found in milk, neutrophil granules, secretions and selected organs of mammals. lactoferrin exhibits antibacterial, antiviral, fungicidal, immunoregulatory and other functions. although fish are devoid of this protein and its cell receptors, lf effect on the immune mechanisms of fish has been demonstrated. the objective of this study was to investigate the effect of bovine lactoferrin, applied in vitro, on the activity of head kidney and spleen leukocytes in thr ...201021077435
sequencing, de novo annotation and analysis of the first anguilla anguilla transcriptome: eeelbase opens new perspectives for the study of the critically endangered european eel.once highly abundant, the european eel (anguilla anguilla l.; anguillidae; teleostei) is considered to be critically endangered and on the verge of extinction, as the stock has declined by 90-99% since the 1980s. yet, the species is poorly characterized at molecular level with little sequence information available in public databases.201021080939
an evaluation of indices of gross pathology associated with the nematode anguillicoloides crassus in eels.this study compares two alternative indices for quantifying the gross pathology of the swimbladder of eels, anguilla anguilla (l.), infected with the nematode anguillicoloides crassus. two observers recorded twice the scores obtained by the two indices on the same set of 71 wild caught eels (from elver to silver eels, french mediterranean lagoons). the length ratio index (lri), performed better than the swimbladder degenerative index (sdi), in three of four predefined criteria of decision. first ...201021118268
enhancement of protective immunity in european eel (anguilla anguilla) against aeromonas hydrophila and aeromonas sobria by a recombinant aeromonas outer membrane develop a vaccine, which can simultaneously prevent the diseases caused by various pathogenic bacteria in fish, we try to find a conserved outer membrane protein (omp) antigen from different bacterial pathogens. in this study, an omp fragment of 747 bp (named as omp-g), which was highly conserved in seven aeromonas omp sequences from the ncbi database, was amplified by pcr from one aeromonas sobria strain (b10) and two aeromonas hydrophila strains (b27 and b33) with the designed specific prim ...201021148192
the european eel-the swim bladder-nematode system provides a new view of the invasion is widely assumed that the likelihood of invasion decreases with increased species richness in the recipient community. however, the invasion paradox supports a negative and a positive relationship between native biodiversity and the success of an invader. here, we show that for a host-parasite system (anguilla anguilla as host and anguillicoloides crassus as parasitic invader), invasion increases with native micro- and macroparasitic species richness. in fact, about 30% of the a. crassus int ...201021184096
migratory life history of european eel anguilla anguilla from freshwater regions of the river asi, southern turkey and their high otolith sr:ca ratios.otolith sr:ca ratios from 32 of 34 european eel anguilla anguilla collected from three freshwater sites in the river asi, southern turkey, indicated that they were resident in fresh water without apparent exposure to salt water since the elver stage. the sr:ca ratio criterion indicative of residence in fresh water was more than twice that of values from other european countries. otolith sr:ca ratios of a. anguilla from fresh waters can vary among regions, possibly reflecting regional-specific wa ...201121366578
too short to spawn? implications of small body size and swimming distance on successful migration and maturation of the european eel anguilla anguilla.individual net fat reserves after migration and reproductive investments were calculated for migrating female silver eels anguilla anguilla (n = 387) collected in the outlet region of the baltic sea during the autumn run. it is estimated that 20·4% of the a. anguilla had completely exhausted all initial fat reserves and that 45·0% of a. anguilla were within 90% of complete energy depletion after migration and reproduction. this study concludes that a combination of body size and distance (6900 k ...201121463308
an infection of gyrodactylus anguillae ergens, 1960 (monogenea) associated with the mortality of glass eels (anguilla anguilla l.) on the north-western mediterranean sea board of spain.the association of gyrodactylus anguillae ergens, 1960 with the glass eel stage of anguilla anguilla (l.) (total body length 61.4±4.9mm; range 55-70) is reported from the north-western mediterranean coast of spain for the first time. a sample of 12,600 glass eels, caught by professional fishermen operating in the mouth of the rivers fluvià, la muga and ter (north-east spain), was subject to mortalities of ∼1.75% of stock/day following transfer to a research facility. subsequent losses over a 31- ...201121482028
early marine migration of european silver eel anguilla anguilla in northern study the migratory behaviour in wild northern european silver eel anguilla anguilla during sea entry and early marine migration, 32 individuals were tagged with acoustic transmitters and registered at four automatic listening station arrays from the mouth of the north norwegian river alta and throughout the alta fjord. the a. anguilla entered the fjord during all parts of the tidal cycle and did not seem to utilize the outgoing tidal currents. they migrated mainly during the night, in both t ...201121539549
surface features of the monogenean gill parasites pseudodactylogyrus anguillae and pseudodactylogyrus bini from the european eel anguilla anguilla in the present study, scanning electron microscopy is used to demonstrate the surface features of pseudodactylogyrus anguillae yin and sproston (1948) gussev, 1965 and pseudodactylogyrus bini kikuchi (1929) gussev, 1965 from the european eel anguilla anguilla. specimens of the eel a. anguilla were collected from the river nile, near mansoura, dakahlia province, egypt. morphologically, p. anguillae could be distinguished from p. bini based on the total length, the shape and size of the haptor, an ...201121647675
first evidence for a direct inhibitory effect of kisspeptins on lh expression in the eel, anguilla anguilla.the kisspeptin system has emerged as one of the main puberty gatekeepers among vertebrates. the european eel (anguilla anguilla) is a remarkable model due to its phylogenetical position at the basis of teleosts, and its unique life cycle with a blockade of puberty before reproductive migration. we cloned the full-length coding sequence of a kisspeptin receptor (kissr) in the eel. comparison of kissr sequences assigned the eel kissr to a basal position in a clade including most of the known teleo ...201121679713
reproduction of european eel jeopardised by high levels of dioxins and dioxin-like pcbs?dioxins, furans and dioxin-like polychlorinated biphenyls (pcbs) were analysed in muscle tissue from yellow phased european eel (anguilla anguilla) from 38 sites in belgium. dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. measured levels of dioxin-like pcbs are much higher than those of the dioxins and furans. in the majority of the sites, eel has levels considered to be detrimental for their rep ...201121714990
an invasion record for the swimbladder nematode anguillicoloides crassus in european eel anguilla anguilla in a deep cold-monomictic lake, from invasion to steady state.this study is the first account of the establishment and development of the neozoic nematode parasite anguillicoloides crassus in its host, the european eel anguilla anguilla, in a deep, cold-monomictic lake. a 21 year study of a. crassus took place in upper lake constance (ulc), europe's second largest pre-alpine lake. the study included two extensive surveys, one in 1991 during the initial parasite invasion phase and the second in 2006 when the infection was well established. the subtropical s ...201121884109
the effect of metals on condition and pathologies of european eel (anguilla anguilla): in situ and laboratory experiments.forty-nine wild eels (anguilla anguilla) caught in the albufera lake (spain), measuring 24.0-75.0cm in length and 25.0-637.7g in weight, were examined for metals (cd, co, cr, cu, fe, hg, mn, pb, se and zn), condition (ci and hsi indices), as well as for diseases (anguillicola infestation; bacterial infections). total metal load significantly increased in eel liver tissue parallel to total length and body weight (log), while silvering females (w(b)>200g; l≥500mm) exhibited the highest amounts of ...201122030412
time trends in fish populations in metropolitan france: insights from national monitoring data.using the electrofishing database of the french national agency for water and aquatic environment (onema), the time trends of 48 freshwater fish taxa at 590 sites monitored for at least 8 years from 1990 to 2009 were investigated. the results demonstrated that species richness increased steadily from the beginning of the monitoring period. this is congruent with the finding that the number of species displaying a significant increase in spatial distribution or abundance was greater than those sh ...201122136235
identification and localization of the structural proteins of anguillid herpesvirus 1.abstract: many of the known fish herpesviruses have important aquaculture species as their natural host, and may cause serious disease and mortality. anguillid herpesvirus 1 (anghv-1) causes a hemorrhagic disease in european eel, anguilla anguilla. despite their importance, fundamental molecular knowledge on fish herpesviruses is still limited. in this study we describe the identification and localization of the structural proteins of anghv-1. purified virions were fractionated into a capsid-teg ...201121975111
Pituitary gonadotropins FSH and LH are oppositely regulated by the activin/follistatin system in a basal teleost, the eel.European eels are blocked at a prepubertal silver stage due to a deficient production of pituitary gonadotropins. We investigated the potential role of activin/follistatin system in the control of eel gonadotropins. Through the development of qPCR assays for European eel activin ß(B) and follistatin, we first analyzed the tissue distribution of the expression of these two genes. Both activin ß(B) and follistatin are expressed in the brain, pituitary and gonads. In addition, a striking expression ...201222019479
Confirmation of the hosts involved in the life cycle of an acanthocephalan parasite of Anguilla anguilla (L.) from Lake Piediluco and its effect on the reproductive potential of its amphipod intermediate host.A total of 37 European eels, Anguilla anguilla, collected from Lake Piediluco, Central Italy, and measuring 35 to 75.5 cm in total length (mean±1 SD, 56.41?±?10.89 cm) were examined, and their acanthocephalan infections assessed. Thirty-two (86.49%) eels were infected with Acanthocephalus rhinensis (mean±1 SD, 67.38?±?65.16; range, 1-350), a species that, purportedly, can be discriminated on the basis of a characteristic band of orange-brown pigmentation encircling the anterior end of the trunk. ...201122167374
The alloherpesviral counterparts of interleukin 10 in European eel and common carp.Viral interleukin 10 (IL-10) like open reading frames have been identified in several pox- and herpesviruses, including the fish herpesviruses Anguillid herpesvirus 1 (AngHV-1) and Cyprinid herpesvirus 3 (CyHV-3). European eel (Anguilla anguilla) IL-10 was sequenced, in order to compare European eel and common carp (Cyprinus carpio) IL-10 with their alloherpesviral counterparts. Homology between the virus and host IL-10 amino acid sequences is low, which is confirmed by phylogenetic analysis. Ho ...201121907290
individual and combined effects of copper and parasitism on osmoregulation in the european eel anguilla anguilla.the european eel (anguilla anguilla), a catadromous species, breeds in the sea and migrates to estuarine, lagoon or freshwater habitats for growth and development. yellow eels, exposed to low or fluctuating salinities, are also exposed to multiple other stressors as pollution, over-fishing and parasitism, which contribute to the dramatic decrease of eel populations in several european countries. the objective of this study was to evaluate the single and combined effects of waterborne copper and ...201223340332
regulation of eel (anguilla anguilla) liver acetyl-coa carboxylase by changes in the polymeric state of the enzyme. 20102905608
the shifting of the aortic origin of the brachial arteries in the metamorphosing eel anguilla anguilla (l.), with remarks on the shifting mechanisms in arterial junctions in silver eels the arteries supplying the pectoral girdles and fins, arise from a common trunk which branches off from the dorsal aspect of the dorsal aorta, while the origin of this trunk is found at the ventral aspect of the aorta in the leptocephalus larva. the rearrangement of the origin of this trunk is mainly accomplished during metamorphosis, and is related to the rearrangement of the junction of the epibranchial arteries and the aorta. the processes of remodelling the wall of the vessels ...20144013636
na-dependent l-proline transport by eel intestinal brush-border membrane vesicles.l-[3h]proline uptake by brush-border membrane vesicles prepared from intestinal mucosa of the european eel, anguilla anguilla, was stimulated by a transmembrane na gradient (out greater than in). kinetic analysis of l-proline influx, under short-circuited membrane potential conditions, indicated the presence of an apparent single na-dependent carrier process (kapp = 0.23 +/- 0.04 mm and jmax = 7.96 +/- 0.87 protein-1.min-1) and a nonsaturable transfer component with an apparent diffusion ...20113177696
cerebrospinal fluid-contacting neurons, ciliated perikarya and "peptidergic" synapses in the magnocellular preoptic nucleus of teleostean fishes.the magnocellular preoptic nucleus of fishes (anguilla anguilla, amiurus nebulosus, cyprinus carpio, carassius auratus, ctenopharyngodon idella, cichlasoma nigrofasciatum) has been studied by light and electron microscopy. two kinds of neurons were found: a) large, electron-dense, gomori-positive cells with moderate acetylcholinesterase (ache) positivity which contain granulated vesicles of 1400 to 2200 a (in average 1600 to 1800 a), adn b) small, strongly ache-positive, electron-lucent neurons ...1987174818
temperature acclimation and oxygen binding properties of blood of the european eel, anguilla anguilla.temperature acclimation of the european eel, anguilla anguilla, resulted in red cell gtp/hb molar ratios of 1.20, 1.77 and 0.80 at 2, 17 and 29 degrees c, respectively. a small increase in blood oxygen capacity was present in 29 degrees c acclimated eels. the co2 bohr effect and the shape of the oxygen binding curve (n-hill) were invariant with both temperature and gtp/hb. the significant differences in the gtp/hb ratio corresponded with a strong enhancement of the temperature effect on blood ox ...20062859959
the capillary endothelium in the rete mirabile of the swimbladder of the eel (anguilla anguilla): functional and ultrastructural aspects. 20164854670
[electron microscopical and ultrahistochemical investigations of erythrocytes from eel (anguilla angiulla) and rainbow-trout (salmo giardneri) under the specific consideration of the segregation apparatus and the marginal band (author's transl)].comparative studies were carried out on the fine structure of the erythrocytes of the european eel (anguilla anguilla) and the rainbow trout (salmo gairdneri) using electron microscopy and ultrahistochemistry. the cell organelles, the marginal band and the segregation apparatus were investigated. the 2 organelles revealed specific differences. an alkaline phosphatase activity was revealed by ultrahistochemistry at the cell surface only, while alternating activities between the nuclear membranes, ...1998104531
white muscle differentiation in the eel (anguilla anguilla l.): changes in the myosin isoforms pattern and atpase profile during post-metamorphic development.myosin isoforms and their light and heavy chains subunits were studied in the white lateral muscle of the eel during the post metamorphic development, in relation with the myosin atpase profile. at elver stage vi a1 the myosin isoforms pattern was characterized by at least two isoforms, fm3 and fm2. the fast isomyosin type 1 (fm1) appeared during subsequent development. it increased progressively in correlation with the increase in the level of the light chain lc3f. fm1 became predominant at sta ...19941534545
properties of european eel (anguilla anguilla) liver cell sap acetyl-coa carboxylase. 20102905607
[postlarval developmental stages of anguilla anguilla l. and their anatomical-histological and histochemical criteria]. 20124771385
coexistence of corticotropin-releasing factor-like immunoreactivity and vasotocin in perikarya of the preoptic nucleus in the eel.a corticotropin-releasing factor (crf)-like system has been identified in eels (anguilla anguilla, a. rostrata, and a. japonica) with immunocytochemical techniques. immunoreactive perikarya were located in the preoptic area, in magno- and parvocellular regions of the preoptic nucleus. fine fibers reached the pituitary and terminated in the neurohypophysis close to the corticotropic cells of the rostral pars distalis and caudally close to the melanocorticotropic cells of the intermediate lobe. do ...20123286370
[neuro-intermediate lobe and osmoregulation: comparison of the european eel and the cultured japanese eel during a transfer from fresh water to sea water]. 20144187662
metabolic effects of technical pentachlorophenol (pcp) on the eel anguilla anguilla l. 20154653160
metabolic and hematological studies on the yellow and silver phases of the european eel, anguilla anguilla l. i. carbohydrate, lipid, protein and inorganic ion metabolism. 20154452230
effects of salinity, hypophysectomy and corticotrophin or branchial na- and k-activated atpase in the eel, anguilla anguilla l. 20154326155
enzyme activity patterns in white and red muscle of the eel (anguilla anguilla) at different developmental stages. 20154342454
[chromatographic separation and determination of hormones of the oxytocin type (arginine-vasotocin and isotocin) from the pituitary and preoptic nucleus of the european eel (anguilla anguilla l.): eels from the baltic sea]. 20164982508
galanin-like immunoreactivity in the brain of teleosts: distribution and relation to substance p, vasotocin, and isotocin in the atlantic salmon (salmo salar).the presence of galanin-like substances and their relation to substance p-, vasotocin-, and isotocin-immunoreactive neurons and fibers in the brain of teleosts was investigated with immunohistochemical methods. two specific antisera against synthetic porcine galanin (gal) revealed cell bodies and fibers in the brain of four different teleost species (salmo salar, carassius carassius, gasterosteus aculeatus, and anguilla anguilla). in all four species the main location of galanin immunoreactivity ...19801713923
metabolic and hematological studies on the yellow and silver phases of the european eel, anguilla anguilla l. iii. hematology. 20154452232
[plasma levels, metabolic clearance rates, and rates of secretion of testosterone and estradiol-l7 beta in the silver eel (anguilla anguilla l.)].testosterone (t) and 17 beta-estradiol (e2) plasma levels and metabolic clearance rates (mcr) were measured to investigate their ovarian production in immature silver eel. the dynamics of t and e2 metabolism were studied in catheterized eels using single injections of 0.2 to 0.5 microci 3h-labeled steroid. the distribution volumes, biological half-life and mcr of nonconjugated tracers were calculated on the basis of a two-compartment model. at the end of the experiments, radioactivity was measur ...20144043727
renal diuresis and antidiuresis after injections of arginine vasotocin in the freshwater eel (anguilla anguilla l.). 20164835434
morphohistochemical changes in hepatocytes during the life cycle of the european eel.the comparative analysis of morphological, histochemical and cytochemical patterns of eel (anguilla anguilla l.) hepatocytes reveals clear differences between two stages of its life cycle, i.e. the trophic stage (yellow eel) and reproductive stage (silver eel). the storage of glycogen prevails in the yellow eel, whilst lipids appear to be remarkably increased in the silver eel, in which some hepatocytes also show glycogen-rich areas. generally, in the silver eel dehydrogenase and acid phosphatas ...20124002214
myo-inositol phosphate synthase expression in the european eel (anguilla anguilla) and nile tilapia (oreochromis niloticus): effect of seawater acclimation.a single mips gene (isyna1/ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (mips) transcript identified in all eel tissues, although two mips spliced variants [termed mips(s) and mips(l)] are found in all tilapia tissues. the larger tilapia transcript [mips(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. in most tilapia tissues, the mips(s) transcript exhibits much higher abundance (generally >10- ...201627252471
comparative evolutionary histories of kisspeptins and kisspeptin receptors in vertebrates reveal both parallel and divergent features.during the past decade, the kisspeptin system has been identified in various vertebrates, leading to the discovery of multiple genes encoding both peptides (kiss) and receptors (kissr). the investigation of recently published genomes from species of phylogenetic interest, such as a chondrichthyan, the elephant shark, an early sarcopterygian, the coelacanth, a non-teleost actinopterygian, the spotted gar, and an early teleost, the european eel, allowed us to get new insights into the molecular di ...201223272003
duplicated leptin receptors in two species of eel bring new insights into the evolution of the leptin system in vertebrates.since its discovery in mammals as a key-hormone in reproduction and metabolism, leptin has been identified in an increasing number of tetrapods and teleosts. tetrapods possess only one leptin gene, while most teleosts possess two leptin genes, as a result of the teleost third whole genome duplication event (3r). leptin acts through a specific receptor (lepr). in the european and japanese eels, we identified two leptin genes, and for the first time in vertebrates, two lepr genes. synteny analyses ...201525946034
identification and characterization of a novel conserved 46 kd maltoporin of aeromonas hydrophila as a versatile vaccine candidate in european eel (anguilla anguilla).european eel (anguilla anguilla) is a crucial economic fish that has been plagued by aeromonas hydrophila infections for many years. vaccines that are cross-protective against multiple serotypes could provide an effective control against a. hydrophila-mediated diseases. the outer membrane proteins (omps) are highly immunogenic and capable of eliciting protective immune responses. this study reports the identification of a novel 46 kd maltoporin that is a conserved protective antigen for differen ...201728279793
the effect of foraging and ontogeny on the prevalence and intensity of the invasive parasite anguillicola crassus in the european eel anguilla anguilla.infection patterns of the invasive anguillicola crassus nematode were investigated in a population of the european eel anguilla anguilla where parasite invasion is very recent, loch lomond, scotland. intensity levels of the parasite were associated with differences in fish ontogeny and trophic ecology. although eels foraged on both fish and invertebrates, individuals which were smaller and fed on invertebrates (>70% contribution to diet) were found to contain a greater number of swim bladder par ...201728084623
anguillicola crassus infection significantly affects the silvering related modifications in steady state mrna levels in gas gland tissue of the european eel.using illumina sequencing, transcriptional changes occurring during silvering in swimbladder tissue of the european eel have been analyzed by comparison of yellow and silver eel tissue samples. functional annotation analysis based on go terms revealed significant expression changes in a number of genes related to the extracellular matrix, important for the control of gas permeability of the swimbladder, and to reactive oxygen species (ros) defense, important to cope with ros generated under hype ...201627242549
anguillicola crassus impairs the silvering-related enhancements of the ros defense capacity in swimbladder tissue of the european eel (anguilla anguilla).in a process called silvering, european eels prepare for their long-distance migration from european freshwater systems to the sargasso sea for reproduction. during this journey, eels perform extended diel vertical migrations, and the concomitant changes in hydrostatic pressure significantly affect the swimbladder, functioning as a buoyancy organ. as the swimbladder is primarily filled with oxygen, the tissue has to cope with extreme hyperoxic conditions, which typically are accompanied by the g ...201627146148
the hsp70 response of anguillicola species to host-specific stressors.the present study is based on infection experiments of two different swim bladder parasite species, anguillicola crassus kuwahara et al., 1974 and anguillicola novaezelandiae moravec and taraschewski, 1988, which were experimentally transferred to the two eel species anguilla anguilla linnaeus, 1758 and anguilla japonica temmink and schlegel, 1846, respectively. the host-parasite groups were selected due to their different grades of mutual adaptation. the main aim of this study was to analyze th ...201626920569
influence of nematode anguillicoloides crassus infestation on the cellular and humoral innate immunity in european eel (anguilla anguilla l.).parasitic invasions are recognized as one of the primary factors responsible for decreasing populations of european eel. the aim of the present study was to determine the influence of infestation with the nematode anguillicoloides crassus on the innate immunity in european eel (anguilla anguilla). anguillicoloides crassus parasitizes the swim bladder of this fish. levels of the following immunological parameters were measured: spleen phagocyte respiratory burst activity, spleen phagocyte potenti ...201526557024
size does matter-a closer look on anguillicola morphology.the present study deals with morphological differences between two closely related parasitic nematode species (anguillicola crassus kuwahara et al., 1974 and anguillicola novaezelandiae moravec & taraschewski, 1988) in two different experimentally infected eel species (anguilla anguilla linnaeus, 1758 and anguilla japonica temminck & schlegel, 1847). furthermore, it considers the question whether size differences between those two species are ontogenetically determined or host species-dependent. ...201526096826
comparative imaging of european eels (anguilla anguilla) for the evaluation of swimbladder nematode (anguillicoloides crassus) infestation.this study compares diagnostic imaging tools in detecting the parasitic swimbladder nematode anguillicoloides crassus in anguilla anguilla (l.) and focuses on ultrasound in an attempt to develop a non-destructive, field diagnostic test. ultrasound use could allow the parasite to be diagnosed without decreasing the number of critically endangered european eels through post-mortem. in the preliminary study, eels were examined with computed radiography, computed tomography, magnetic resonance imagi ...201625952716
competing invaders: performance of two anguillicola species in lake bracciano.anguillicola crassus is one of the most successful parasitic invasive species as it has spread from its original habitat in east asia throughout the world and has acquired five new eel host species in the course of its invasion within the last three decades. records from an italian lake indicate that this species has even displaced an established population of its close relative a. novaezelandiae originating from new zealand. in order to analyze the reasons for its high invasive potential, this ...201525830111
relationship between european eel anguilla anguilla infection with non-native parasites and swimming behaviour on encountering accelerating flow.the effect of anguillicola crassus, pseudodactylogyrus bini and pseudodactylogyrus anguillae infection on the behaviour of downstream migrating adult european eels anguilla anguilla as they encountered accelerating water velocity, common at engineered structures where flow is constricted (e.g. weirs and bypass systems), was evaluated in an experimental flume. the probability of reacting to, and rejecting, the velocity gradient was positively related to a. crassus larval, adult and total abundanc ...201525801939
swimbladder function and the spawning migration of the european eel anguilla anguilla.the spawning migration of the european eel is an extensive journey over 5000 to 7000 km from the european coast to the sargasso sea. eels do not feed during this journey and on-board fuels must be sufficient to support the journey of 3.5 to 6 month, as well as sexual maturation and the spawning activity. swimming of eels appears to be quite energy efficient compared to other fish species, and elevated hydrostatic pressure has been shown to even reduce the costs of transport. recent studies revea ...201425646080
transcriptome analyses of anguillicola crassus from native and novel hosts.anguillicola crassus is a swim bladder nematode of eels. the parasite is native to the asian eel anguilla japonica, but was introduced to europe and the european eel anguilla anguilla in the early 1980s. a taiwanese source has been proposed for this introduction. in the new host in the recipient area, the parasite appears to be more pathogenic. as a reason for these differences, genetically fixed differences in infectivity and development between taiwanese and european a.crassus have been descri ...201425469324
influence of adult anguillicoloides crassus load in european eels swimbladder on macrophage response.anguillicoloides crassus has become one of the most important threats to the european eel (anguilla anguilla). adult parasites colonize the swimbladder leading to an impaired functioning of this organ. the infection is also responsible for an increased in the stress level of infected eels, that could produce an altered immune response as well. differences in parasite loads and effects in the european and japanese eel (anguilla japonica) have been described. we have studied the influence of the n ...201525463301
nematode eel parasite found inside acanthocephalan cysts--a "trojan horse" strategy?the invasive eel parasite anguillicoloides crassus (syn. anguillicola crassus) is considered one of the major causes for the decline of the european eel (anguilla anguilla) panmictic population. it impairs the swim bladder function and reduces swimming performance of its host. the life cycle of this parasite involves different intermediate and paratenic hosts. despite an efficient immune system of the paratenic fish hosts acting against infections with a. crassus, levels of parasitized eels rema ...201425403767
effects of anguillicola novaezelandiae on the levels of cortisol and hsp70 in the european eel.the nematodes anguillicola novaezelandiae and anguillicola crassus are both alien parasites of the european eel with severe adverse effects on their new host. both species differ in terms of their invasiveness and their severity of harmful effects on the european eel. the purpose of this study was to determine under laboratory conditions whether stages of a. novaezelandiae induce stress in european eels (anguilla anguilla) and if these levels differ from stress levels induced by a. crassus. we a ...201425096532
brush-border amino acid transport mechanisms in carnivorous eel intestine.brush-border membrane vesicles (bbmv) were prepared from european eel (anguilla anguilla) intestinal epithelium by a magnesium-ethylene glycolbis(beta-aminoethyl ether)-n,n,n',n'-tetraacetic acid (egta) precipitation technique. amino acid transport by these purified vesicle preparations was investigated using either radiolabeled substrates or the voltage-sensitive fluorescent dye 3,3'-diethylthiadicarbocyanine iodide [disc2(5)]. all amino acids tested exhibited carrier-mediated, na+-dependent an ...20092782453
comparison of infection success, development and swim bladder pathogenicity of two congeneric anguillicola species in experimentally infected anguilla anguilla and a. japonica.two closely related parasites, anguillicola crassus and anguillicola novaezelandiae, originally parasitizing swim bladders of the japanese eel (anguilla japonica and the short-finned eel (anguilla australis), respectively, were used for analyzing the infection success of each parasite species on either long-known, recently acquired or new definitive host species and the associated effects on the eels' swim bladders. on that account, european eels (anguilla anguilla) and japanese eels were experi ...201425070578
introduced american eels anguilla rostrata in european waters: life-history traits in a non-native environment.this study investigated growth, condition and development of american eels anguilla rostrata that were introduced into a european river to estimate their competitive potential in a non-native habitat. results demonstrate that a. rostrata develops normally in european waters and successfully competes with the native european eel anguilla anguilla. in addition, a. rostrata appears to be more susceptible to the asian swimbladder nematode anguillicola crassus than a. anguilla and could support the f ...201424787669
richness and diversity of helminth species in eels from a hypersaline coastal lagoon, mar menor, south-east spain.the composition and diversity of parasite communities and intestinal components, as well as infra-community structure, were assessed in eels anguilla anguilla, from mar menor, a permanent mediterranean hypersaline coastal lagoon. data were used to determine whether this helminth community differs in composition and structure from that of eels in lagoons with lower salinity regimes and higher freshwater inputs. a total prevalence of 93% was detected. specifically, parasites were identified as der ...201524685015
distribution, prevalence and intensity of anguillicola crassus (nematoda) infection in anguilla anguilla in the republic of ireland.this study is the first comprehensive documentation of the geographical range of anguillicola crassus in its host, the european eel anguilla anguilla, in the republic of ireland. the prevalence and intensity of infections across 234 sites and 93 river basins in ireland comprising rivers, lakes and transitional waters (estuaries) were analysed. while only 32% of the river basins were affected by this nematode, they correspond to 74% of the total wetted area. significant differences in infection l ...201424627948
the aetiology, histopathology, and ultrastructural features of perianal erythema (red anus syndrome) in the european eel (anguilla anguilla).the european eel (anguilla anguilla) is a critically endangered species. red anus syndrome (ras) is known to be associated with parasitic infections of the eel, particularly with anguillicola crassus, but the full range of causative pathogenic organisms has not been systematically investigated. here we examined the infective organisms and histopathological and ultrastructural features of seventy eels with ras. in total, nine different pathogens were detected in association with ras: pseudomonas ...201424608418
introduced parasite anguillicola crassus infection significantly impedes swim bladder function in the european eel anguilla anguilla (l.). 201424422641
temporal and spatial changes in the composition and structure of helminth component communities in european eels anguilla anguilla in an adriatic coastal lagoon and some freshwaters in italy.the composition and diversity of the helminth component communities in eels anguilla anguilla were determined in three separate localities in italy: an adriatic coastal lagoon, comacchio and two freshwater localities, the river po and the lake piediluco. data from comacchio lagoon were analysed over 15 years to determine whether community composition and diversity changed significantly overtime. the community was species rich (nine species, all marine except proteocephalus macrocephalus) and was ...201424135871
influence of introduced vs. native parasites on the body condition of migrant silver eels.because parasitism is among the reasons invoked to explain the collapse of anguilla anguilla, we evaluated the parasitic constraint on body condition (bc) of migrant silver eels as a proxy of fitness with inter-site comparisons. metazoan parasites were studied in 149 silver eels from five sites (northern europe). in total, 89% were infected by 13 species including myxozoa, monogenea, cestoda, nematoda, and acanthocephala. anguillicoloides crassus was most common (56%), then acanthocephalus clavu ...201324135272
can differences in life cycle explain differences in invasiveness? - a study on anguillicola novaezelandiae in the european eel.anguillicola crassus is the most invasive species of its genus and it is a successful colonizer of different eel species worldwide. it is so far the only species of the genus anguillicola whose life cycle has been studied completely. to analyse whether differences in life cycle may explain differences in invasiveness, we infected european eels with anguillicola novaezelandiae under laboratory conditions. anguillicola novaezelandiae shows a synchronized development in the european eel. eggs with ...201323953638
influence of site, season, silvering stage, and length on the parasites of the european eel anguilla anguilla in two mediterranean coastal lagoons of the island of corsica, france using indicator species method.the parasites of 425 european eels, anguilla anguilla, were studied between 2009 and 2012 in two mediterranean coastal lagoons of the island of corsica, france. an indicator value (indval) method was used for analysis, which combines measures of fidelity and specificity. because of its resilience to detect changes in abundance, indval is an effective ecological bioindicator. the indval method demonstrated that site, season, silvering stage, and length could influence the occurrence of parasite s ...201323739809
evolutionary divergence of the swim bladder nematode anguillicola crassus after colonization of a novel host, anguilla anguilla.anguillicola crassus, a swim bladder nematode naturally parasitizing the japanese eel, was introduced about 30 years ago from east asia into europe where it colonized almost all populations of the european eel. we conducted a common garden experiment under a reciprocal transfer design infecting both european and japanese eels with populations of a. crassus from germany, poland and taiwan. we tested, whether differences in infectivity, developmental dynamics and reproductive output between the eu ...201323566258
the transcriptome of the invasive eel swimbladder nematode parasite anguillicola crassus.anguillicola crassus is an economically and ecologically important parasitic nematode of eels. the native range of a. crassus is in east asia, where it infects anguilla japonica, the japanese eel. a. crassus was introduced into european eels, anguilla anguilla, 30 years ago. the parasite is more pathogenic in its new host than in its native one, and is thought to threaten the endangered an. anguilla across its range. the molecular bases for the increased pathogenicity of the nematodes in their n ...201323394720
is the continental life of the european eel anguilla anguilla affected by the parasitic invader anguillicoloides crassus?quantifying the fitness cost that parasites impose on wild hosts is a challenging task, because the epidemiological history of field-sampled hosts is often unknown. in this study, we used an internal marker of the parasite pressure on individual hosts to evaluate the costs of parasitism with respect to host body condition, size increase and reproductive potential of field-collected animals for which we also determined individual age. in our investigated system, the european eel anguilla anguilla ...201323325776
merging species? evidence for hybridization between the eel parasites anguillicola crassus and a. novaezelandiae (nematoda, anguillicolidea).the eel parasitic nematodes anguillicola crassus (originating from asia) and anguillicola novaezelandiae (originating from new zealand) were both introduced to europe, but occurred in sympatry only in lake bracciano in italy, where they both infected the european eel (anguilla anguilla). a. novaezelandiae was introduced to the lake in 1975 and disappeared soon after a. crassus was also found there in 1993. we tested the hypothesis if hybridization of the two species might be an explanation for t ...201223111012
contamination, parasitism and condition of anguilla anguilla in three italian conjunction with habitat loss and overfishing, pollution and parasitism are believed to be relevant causes of collapse of anguilla, as these can affect eel swimming ability and the development of gonads and embryos. the present study investigated persistent organic pollutant (pop) concentrations, infection levels of anguillicoloides crassus, lipid content and gonad abnormalities in eels sampled in 2007-2008 in three italian water bodies (caprolace lake, lesina lagoon and tevere river) that va ...201323076840
infection of european eel, anguilla anguilla (l.), with the nematode anguillicoloides crassus (kuwahara, niimi et itagaki, 1974) in polish waters.the aim of this study was to determine the degree of anguillicoloides crassus infection in european eel inhabiting polish waters based on selected parasitic descriptors and on anatomical pathology of the swimbladder using macroscopic methods. in all, 154 european eel specimens were sampled from eleven sites in poland and a. crassus was present in the swimbladder of 114 fish. the intensity of a. crassus infection in all the eel specimens ranged from 1 to 62 parasites at a mean value of 7.5. high ...201222844702
Displaying items 301 - 400 of 1365