TitleAbstractYear(sorted ascending)
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
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
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
european eel sperm diluent for short-term storage.the sperm of european eel shows a high density and the time of spermatozoa motility is very short after activation with sea water. these characteristics make difficult the sperm handling and its quality assessment. several diluents were previously described for the japanese eel obtaining over 3 weeks' conservation times under refrigeration, but they rendered bad results in the european species. in the present study, several diluents were developed taking as basis the p1 medium, and using differe ...201018954399
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
properties of european eel (anguilla anguilla) liver cell sap acetyl-coa carboxylase. 20102905607
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
regulation of eel (anguilla anguilla) liver acetyl-coa carboxylase by changes in the polymeric state of the enzyme. 20102905608
divergence between asian, european and canadian populations of the monogenean pseudodactylogyrus bini indicated by ribosomal dna patterns.the monogenean pseudodactylogyrus bini parasitizes the gills of eels belonging to the genus anguilla. circumstantial evidence suggests that the parasite has been spread accidentally from the pacific area (east asia) to europe by the intercontinental eel trade. this is based on early descriptions of the parasites from asian regions and the lack of records of the parasites in europe before 1977. in addition, the susceptibility of european eels to infections with the parasite is significantly highe ...201020230654
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
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
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
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
intra-specific scaling of natural mortality in fish: the paradigmatic case of the european eel.identifying factors and processes influencing natural mortality is fundamental to the understanding of population dynamics. metabolic theory of ecology and experimental studies at the cross-species level suggest the existence of general patterns linking natural mortality to body mass and temperature. however, there is scant evidence that similar relationships also hold at the intra-specific scale, possibly because of the relatively narrow range of sizes and temperatures experienced by most speci ...201120665048
influence of oceanic factors on anguilla anguilla (l.) over the twentieth century in coastal habitats of the skagerrak, southern norway.the european eel (anguilla anguilla l.) is distributed in coastal and inland habitats all over europe, but spawns in the sargasso sea and is thus affected by both continental and oceanic factors. since the 1980s a steady decline has been observed in the recruitment of glass eels to freshwater and in total eel landings. the eel is considered as critically endangered on the international union for the conservation of nature and natural resources red list of species. the skagerrak beach seine surve ...201120798112
cholinesterase activities and sensitivity to pesticides in different tissues of silver european eel, anguilla anguilla.cholinesterase (che) activities were characterized in silver european eel, anguilla anguilla, grown in the brackish lagoon of comacchio (italy). all specimens were harvested at the "lavoriero", a traditional eel trapping weir that captures eels while leaving internal waters at the onset of reproductive migration. to our knowledge, no investigation on che was reported in silver eels. therefore a first characterization of enzyme activity in muscle, brain, liver and plasma of silver eel was carried ...201121777695
an integrated genetic-demographic model to unravel the origin of genetic structure in european eel (anguilla anguilla l.).the evolutionary enlightened management of species with complex life cycles often requires the development of mathematical models integrating demographic and genetic data. the genetic structure of the endangered european eel (anguilla anguilla l.) has been thoroughly analyzed in several studies in the past years. however, the interpretation of the key demographic and biologic processes that determine the observed spatio-temporal genetic structure has been very challenging owing to the complex li ...201125568002
genetic patchiness in european eel adults evidenced by molecular genetics and population dynamics modelling.disentangling the demographic processes that determine the genetic structure of a given species is a fundamental question in conservation and management. in the present study, the population structure of the european eel was examined with a multidisciplinary approach combining the fields of molecular genetics and population dynamics modelling. first, we analyzed a total of 346 adult specimens of known age collected in three separate sample sites using a large panel of 22 est-linked microsatellit ...201121129491
development and validation of a two-step real-time rt-pcr for the detection of eel virus european x in european eel, anguilla anguilla.eel virus european x (evex) is one of the most common pathogenic viruses in farmed and wild european eel (anguilla anguilla) in the netherlands. the virus causes a hemorrhagic disease resulting in increased mortality rates. cell culture and antibody-based detection of evex are laborious and time consuming. therefore, a two-step real-time reverse transcriptase (rt-)pcr assay was developed for rapid detection of evex. primers and probe for the assay were designed based on a sequence of the rna pol ...201121126538
temperature dependency of element incorporation into european eel (anguilla anguilla) otoliths.the present study experimentally tested the influence of water temperature on the inclusion of 15 elements into juvenile european eel (anguilla anguilla) otoliths in freshwater. it should be investigated (1) if temperature effects on otolith sr/ca might impair the interpretation of migration studies and (2) if the elemental composition of otoliths can be used to reconstruct experienced temperature histories of eels. therefore, eels were kept under full experimental conditions at three different ...201121107822
differential timing of gene expression regulation between leptocephali of the two anguilla eel species in the sargasso sea.the unique life-history characteristics of north atlantic catadromous eels have long intrigued evolutionary biologists, especially with respect to mechanisms that could explain their persistence as two ecologically very similar but reproductively and geographically distinct species. differential developmental schedules during young larval stages have commonly been hypothesized to represent such a key mechanism. we performed a comparative analysis of gene expression by means of microarray experim ...201122393514
molecular and biochemical biomarkers in environmental monitoring: a comparison of biotransformation and antioxidant defense systems in multiple tissues.the cytochrome p450 pathway and antioxidant responses are known for their responsiveness to environmental pollutants and are frequently used as biomarkers at the transcriptional, translational and catalytic levels. although molecular responses are often assumed to reflect similar changes in enzyme function, several factors can influence intracellular effects, including mrna stability and protein turnover, signal sensing and transduction, post-translational modifications of proteins, and multiple ...201122099345
induced oogenesis of the european eel (anguilla anguilla l.) in freshwater condition.european eel is a catadromous fish species, which means that after living in freshwater premature individuals adapt to sea water, and migrate to the sargasso sea for spawning. although male eel can be sexually matured even in freshwater, to date, it was believed that female eel can be matured only in seawater. here we show that the process of sexual maturation may be induced in freshwater by treating female eels with carp pituitary (gsi = 9.87 ± 1.55%). it is thus proposed that seawater conditio ...201122119876
myxosporean hyperparasites of gill monogeneans are basal to the multivalvulida.myxosporeans are known from aquatic annelids but parasitism of platyhelminths by myxosporeans has not been widely reported. hyperparasitism of gill monogeneans by myxidium giardi has been reported from the european eel and myxidium-like hyperparasites have also been observed during studies of gill monogeneans from malaysia and japan.the present study aimed to collect new hyperparasite material from malaysia for morphological and molecular descriptions. in addition, pcr screening of host fish was ...201122115202
persistent organic pollutants (pops) in fish collected from the urban tract of the river tiber in rome (italy).european eel and chub samples were analyzed to determine the levels of non-dioxin-like polychlorobiphenyls (ndl-pcbs), polychlorodibenzodioxins (pcdds) and polychlorodibenzofurans (pcdfs), dioxin-like pcbs (dl-pcbs), and brominated polybromodiphenyl ethers (pbdes) in order to evaluate the extent of contamination of the river tiber along the urban tract through the city of rome (italy). all samples presented detectable levels of the chemicals analyzed, and exhibited species-specific differences i ...201121952158
influence of temperature regime on endocrine parameters and vitellogenesis during experimental maturation of european eel (anguilla anguilla) females.we examined the effect of temperature in european silver eels during their maturation induced by injections of carp pituitary extract on endocrine parameters: pituitary fshβ and lhβ expression, plasma 17β-estradiol (e2) and vitellogenin, estrogen receptor 1 (esr1), and vitellogenin 2 (vtg2) expression in liver. a variable thermal regime (t10) that increased from 10° to 14° and 17°c was compared with a constant 20°c regime (t20) during 12 weeks. t10 caused a faster development until week 8, highe ...201121871894
pop up satellite tags impair swimming performance and energetics of the european eel (anguilla anguilla).pop-up satellite archival tags (psats) have recently been applied in attempts to follow the oceanic spawning migration of the european eel. psats are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does the potential implication for successful migration. silver eels (l(t) = 598.6±29 mm sd, n = 9) were subjected to swimming trials in a steffensen-type swim tunnel at increasing speeds of 0.3-0.9 body lengths ...201121687674
experimental quantification of the swimming performance and behaviour of spawning run river lamprey lampetra fluviatilis and european eel anguilla anguilla.using a large-scale open-channel flume, the swimming ability and behaviour of individual adult european eel anguilla anguilla and river lamprey lampetra fluviatilis, species that exhibit anguilliform locomotion, were quantified under complex hydraulic conditions created by a 0·2-0·3 m high under- or overshot weir during four discharge regimes. fishes were allowed to approach the weirs from both up- and downstream. all fishes passed the undershot weir, independent of discharge and direction of mo ...201121651544
dramatic effect of pop-up satellite tags on eel swimming.the journey of the european eel to the spawning area in the sargasso sea is still a mystery. several trials have been carried out to follow migrating eels with pop-up satellite tags (psats), without much success. as eels are very efficient swimmers, tags likely interfere with their high swimming efficiency. here we report a more than twofold increase in swimming cost caused by a regular small satellite tag. the impact was determined at a range of swimming speeds with and without tag in a 2-m swi ...201121594613
catadromous eels continue to be slippery research adults, atlantic eels (anguilla rostrata in the americas and anguilla anguilla in europe) are tubular slime-covered fish that spend most of their catadromous life-cycle in coastal environs before swimming far out to sea to reproduce, as part of an intergenerational migratory circuit that provides an interesting reversal of the pattern displayed by adult anadromous salmon that live mostly in the ocean but then migrate long distances to spawn in freshwater streams. earlier genetic findings on a ...201121544942
the use of eugenol and electro-narcosis as anaesthetics: transcriptional impacts on the european eel (anguilla anguilla l.).ecotoxicological studies aim to assess the potential environmental risks of various products. this implies the use of various biological models and tests on live animals. in case of handling fish and mammals, ethical rules have to be respected. the use of anaesthesia is considered to be the best way to ensure animal welfare. eugenol and electro-narcosis are among the most popular chemical and physical anaesthetics used in fisheries and by field biologists. in this study, the genetic and endocrin ...201121531020
heavy metals and organochlorinated compounds in the european eel (anguilla anguilla) from the adour estuary and associated wetlands (france).heavy metals and organic pollutants were investigated in the adour estuary (south west france) and associated wetlands using the european eel (anguilla anguilla) as a bioindicator. heavy metals (cu, cd, zn, pb, and ag) were measured in soft tissue of yellow eels. mercury (total hg and mehg) and organochlorinated compounds (7 pcbs, 11 ocps) were analysed in muscle. concentrations in muscle were in agreement with moderately contaminated environments in europe and were below the norms fixed for eel ...201121468402
fitness consequences of individual specialisation in resource use and trophic morphology in european eels.individual specialisation can lead to the exploitation of different trophic and habitat resources and the production of morphological variability within a population. although the ecological causes of this phenomenon are relatively well known, its consequences on individual fitness are less recognised. we have investigated the extent of individual specialisation in resource use and trophic morphology and its fitness consequences through a combination of tagging-recapture, stable isotope analyses ...201121455773
video tracking in the extreme: a new possibility for tracking nocturnal underwater transparent animals with fluorescent elastomer tags.initially developed so that an individual could be recognized in mark-recapture studies of aquatic animals, fluorescent visible implant elastomer (vie) tags are used here for a new application in ethometry: the study of the behavior of transparent animals in dim light or in darkness using automatic tracking technology. the application and validation of this multitracking method is tested in the context of research on the estuarine migratory behavior of the glass eel (anguilla anguilla), a crucia ...201121416308
first artificial hybrid of the eel species anguilla australis and anguilla anguilla.studies on artificial hybridization of different anguilla species were conducted recently, i.e. female a. australis with male a. dieffenbachii, and female a. japonica with male a. anguilla. the existence of these artificial hybrids was however not demonstrated by independent genetic methods. two species - a. anguilla and a. australis - that are phylogenetically close but have different sexual maturation times (12-25 weeks and 6-8 weeks, respectively), were expected to produce favourable hybrids ...201121396126
kinematics of swimming in two burrowing anguilliform fishes.anguilliform or eel-like fishes are typically bottom dwellers, some of which are specialized burrowers. although specializations for burrowing are predicted to affect the kinematics of swimming, it remains unknown to what extent this is actually the case. here we examine swimming kinematics and efficiency of two burrowing anguilliform species, pisodonophis boro and heteroconger hassi, with different degrees of specialization for burrowing. our data suggest that differences in the swimming kinema ...201121392954
the european eel quality database: towards a pan-european monitoring of eel quality.the stocks of the european eel anguilla anguilla are in decline and there is an increasing awareness that poor health status due to contaminants and/or diseases might be a key element in this decline and might be a hindrance to recovery. many countries have started compiling data on the health status of eels in their water bodies. objectives for these monitoring actions are diverse and there is a large amount of information collected by eu member countries. however, this information is widely sc ...201121374055
in vitro aerobic and anaerobic muscle capacities in the european eel, anguilla anguilla: effects of a swimming order to have a general view of metabolic requirements during swimming, in vitro aerobic and anaerobic fluxes were measured in red and white muscles from silver eels and yellow eels which differ in activity levels and nutritional states. these measurements were performed in control eels and after a 4 day swimming session (70% u(crit) in yellow eels, 80% u(crit) in silver eels). a swimming session significantly increases u(crit) from 12% to 18%, depending on the stage, with a significantly hig ...201121316488
all roads lead to home: panmixia of european eel in the sargasso sea.european eels (anguilla anguilla) spawn in the remote sargasso sea in partial sympatry with american eels (anguilla rostrata), and juveniles are transported more than 5000 km back to the european and north african coasts. the two species have been regarded as classic textbook examples of panmixia, each comprising a single, randomly mating population. however, several recent studies based on continental samples have found subtle, but significant, genetic differentiation, interpreted as geographic ...201121299662
prolonged feed deprivation does not permanently compromise digestive function in migrating european glass eels anguilla anguilla.the effects of prolonged feed deprivation (40 days at 18° c) and re-feeding (30 days) on body mass, growth and the activity of selected pancreatic and intestinal enzymes were evaluated in migrating european glass eels anguilla anguilla by comparison with a control group fed to satiation with hake merluccius merluccius roe for the duration of the experiment. feed deprivation resulted in mass loss and a reduction in digestive function, as revealed by a decrease in the total and specific activities ...201121284636
assessing sediment hazard through a weight of evidence approach with bioindicator organisms: a practical model to elaborate data from sediment chemistry, bioavailability, biomarkers and ecotoxicological bioassays.quality assessments are crucial to all activities related to removal and management of sediments. following a multidisciplinary, weight of evidence approach, a new model is presented here for comprehensive assessment of hazards associated to polluted sediments. the lines of evidence considered were sediment chemistry, assessment of bioavailability, sub-lethal effects on biomarkers, and ecotoxicological bioassays. a conceptual and software-assisted model was developed with logical flow-charts ela ...201121239037
the decline of the european eel anguilla anguilla: quantifying and managing escapement to support conservation.a method was developed to quantify the number and biomass of european eels anguilla anguilla escaping to the ocean for breeding. the non-intrusive method, involving a fixed-position, high-frequency multi-beam sonar, permitted constant surveillance of a. anguilla movements throughout their 5 month escapement season (july to december). during this period, >1000 individuals were monitored escaping to the atlantic ocean from their freshwater habitat in the river huntspill study site (somerset, u.k.) ...201121235544
morphological and histochemical study of intestine in wild and reared european eel (anguilla anguilla l.).diet-related differences between the ratio of intestine length to body size and the enzymatic activity in the intestinal tract of wild and reared european eel (anguilla anguilla l.) were studied. compared with reared eel, wild eel showed significantly shorter relative intestine length. for the purpose of histochemical examination, different parts (anterior, middle and posterior) of intestine proper were used. activities of non-specific esterase, alkaline and acid phosphatase, and aminopeptidase ...201221818542
accumulation of mn, co, zn, rb, cd, sn, ba, sr, and pb in the otoliths and tissues of eel (anguilla anguilla) following long-term exposure in an estuarine environment.aiming at increasing the resolution of otolith tracers, we investigated the possibility to use mn, co, zn, rb, cd, sn, ba, sr, and pb otolith composition to retrieve the movements of eels (anguilla anguilla) in the lower gironde watershed. caging experiments were designed to validate the site specific otolith signatures. individually identified eels were reared in cages in three locations along the estuarine and river gradient. three trials were set up for successive periods of 3 months and 6 mo ...201222954653
topography and ultrastructure of the tegument of lecithochirium musculus (digenea: hemiuridae), a parasite of the european eel anguilla anguilla (osteichthyes: anguillidae).the tegumental ultrastructure of the stomach fluke lecithochirium musculus was studied using scanning and transmission electron microscopy. the surface of the tegument was smooth and covered by transverse cytoplasmic ridges. cobblestone-like units of the tegument were observed on the ventral surface. invagination and evagination of the ecsoma induced variations in the tegumental surface. the ultrastructural study revealed that the tegument of l. musculus had a typical syncytial organization with ...201222109611
a multidisciplinary weight of evidence approach for classifying polluted sediments: integrating sediment chemistry, bioavailability, biomarkers responses and bioassays.evaluation of chemical bioavailability and onset of biological alterations is fundamental to assess the hazard of environmental pollutants, particularly when associated to sediments which need to be removed. in the present work, five sediment samples were collected from the venice lagoon and data from sediment chemistry were integrated with those of bioaccumulation of chemicals in european eel (anguilla anguilla) exposed under laboratory conditions, responses of a wide battery of biomarkers, and ...201221982029
primitive duplicate hox clusters in the european eel's genome.the enigmatic life cycle and elongated body of the european eel (anguilla anguilla l., 1758) have long motivated scientific enquiry. recently, eel research has gained in urgency, as the population has dwindled to the point of critical endangerment. we have assembled a draft genome in order to facilitate advances in all provinces of eel biology. here, we use the genome to investigate the eel's complement of the hox developmental transcription factors. we show that unlike any other teleost fish, t ...201222384188
comparative genomics reveals adaptive protein evolution and a possible cytonuclear incompatibility between european and american eels.during the early stages of speciation, interspecific gene flow may be impeded by deleterious epistatic interactions in hybrids, which maintain parental allelic combinations at the speciation genes. the resulting semipermeable nature of the barrier to interspecific gene flow provides a valuable framework to identify the genes involved in hybrid mortality or sterility, as well as the evolutionary mechanisms that initially caused their divergence. the two atlantic eels anguilla anguilla and a. rost ...201222362081
ultrastructural study of spermiogenesis and the spermatozoon of acanthocephaloides incrassatus (molin, 1858) (acanthocephala, paleacanthocephala, arhythmacanthidae) from anguilla anguilla (pisces, teleostei) in urbino ponds (corsica island).this study deals with first ultrastructure features of acanthocephaloides incrassatus (paleacanthocephala, arhythmacanthidae), a parasite of the fish anguilla anguilla, reported for the first time in a mediterranean pond. the spermiogenesis of a. incrassatus shows original specificities which have never been pointed out to this day in ultrastructural studies on spermiogenesis: the centriolar derivative is divided into two parts of different densities: an electron-dense, and the other, electron-l ...201222307764
fish welfare assurance system: initial steps to set up an effective tool to safeguard and monitor farmed fish welfare at a company level.the objective was to take a first step in the development of a process-oriented quality assurance (qa) system for monitoring and safeguarding of fish welfare at a company level. a process-oriented approach is focused on preventing hazards and involves establishment of critical steps in a process that requires careful control. the seven principles of the hazard analysis critical control points (haccp) concept were used as a framework to establish the qa system. haccp is an internationally agreed ...201222278705
do ocean-based wind farms alter the migration pattern in the endangered european silver eel (anguilla anguilla) due to noise disturbance? 201222278527
dna damage in fish (anguilla anguilla) exposed to a glyphosate-based herbicide -- elucidation of organ-specificity and the role of oxidative stress.organophosphate herbicides are among the most dangerous agrochemicals for the aquatic environment. in this context, roundup(®), a glyphosate-based herbicide, has been widely detected in natural water bodies, representing a potential threat to non-target organisms, namely fish. thus, the main goal of the present study was to evaluate the genotoxic potential of roundup(®) in the teleost fish anguilla anguilla, addressing the possible causative involvement of oxidative stress. fish were exposed to ...201222266476
the silvering process of european eel (anguilla anguilla) influences pah metabolite concentrations in bile fluid: consequences for monitoring.the stock of the catadromous european eel (anguilla anguilla l.) continues to decline and there is growing evidence that poor health status due to contaminants might be a key element in this decrease. organic contaminants such as polycyclic aromatic hydrocarbons (pahs) belong to the major threats to yellow eel in their growth habitat and their metabolites are detectable in the bile. starting the silvering process eels undergo physiological and morphological changes including cessation of feeding ...201222209300
biomonitoring of polychlorinated biphenyls (pcbs) in heavily polluted aquatic environment in different fish species.the distribution and concentrations of polychlorinated biphenyls (pcbs) were determined in fish species (european perch perca fluviatilis, northern pike esox lucius, pike perch sander lucioperca, wels catfish silirus glanus, common carp cyprinus carpio, european eel anguilla anguilla, freshwater bream abramis brama, goldfish carassius auratus, and roach rutilus rutilus) in a heavily polluted water reservoir zemplínska šírava (slovakia). the study performed at two different time points 5 years ap ...201222173787
changes in hormonal profile, gonads and sperm quality of argyrosomus regius (pisces, scianidae) during the first sexual differentiation and the present study, sexual gonadal differentiation and first sexual maturation of meagre (argyrosomus regius) was studied, based upon the annual changes in gonadosomatic index (gsi), gonadal histology, and the plasma steroid hormones, testosterone (t), 11-ketotestosterone (11-kt), and estradiol (e2). in addition, spermatozoa characteristics were evaluated by measuring sperm motility and morphology. results demonstrated that meagre completes sex differentiation at 10 to 12 mo of age, and are gr ...201222153261
metabolites of polycyclic aromatic hydrocarbons (pahs) in bile as biomarkers of pollution in european eel (anguilla anguilla) from german the light of the alarming decline of the european eel (anguilla anguilla l.) population, there is an urgent need to define ecological indicators for eel habitat quality. due to an increasing shortage of glass eels available for local stock enhancement, the decision of whether restocking is a valuable management tool to increase high-quality silver eel escapement to the sea needs to be evaluated. organic contaminants, such as polycyclic aromatic hydrocarbons (pahs), are among the major threats ...201221706228
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
[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
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
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
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
aleuria aurantia lectin exhibits antifungal activity against mucor racemosus.aleuria aurantia lectin (aal) is an l-fucose-specific lectin produced in the mycelia and fruit-bodies of the widespread ascomycete fungus aleuria aurantia. it is extensively used in the detection of fucose, but its physiological role remains unknown. to investigate this, we analyzed the interaction between aal and, a zygomycete fungus mucor racemosus, which is assumed to contain fucose in its cell wall. aal specifically bound to the hyphae of m. racemosus, because binding was inhibited by l-fuco ...201222738968
koi herpesvirus encodes and expresses a functional interleukin-10.koi herpesvirus (khv) (species cyprinid herpesvirus 3) orf134 was shown to transcribe a spliced transcript encoding a 179-amino-acid (aa) interleukin-10 (il-10) homolog (khvil-10) in koi fin (kf-1) cells. pairwise sequence alignment indicated that the expressed product shares 25% identity with carp il-10, 22 to 24% identity with mammalian (including primate) il-10s, and 19.1% identity with european eel herpesvirus il-10 (ahvil-10). in phylogenetic analyses, khvil-10 fell in a divergent position ...201222896613
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
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
the phylogenetics of anguillicolidae (nematoda: anguillicoloidea), swimbladder parasites of eels.anguillicolidae yamaguti, 1935 is a family of parasitic nematode infecting fresh-water eels of the genus anguilla, comprising five species in the genera anguillicola and anguillicoloides. anguillicoloides crassus is of particular importance, as it has recently spread from its endemic range in the eastern pacific to europe and north america, where it poses a significant threat to new, naïve hosts such as the economic important eel species anguilla anguilla and anguilla rostrata. the anguillicolid ...201222559142
swim bladder nematodes (anguillicoloides crassus) disturb silvering in european eels (anguilla anguilla).the introduced parasite anguillicoloides crassus is thought to play an important role in the decline of freshwater eel (anguilla spp.) populations. these nematodes are known to negatively affect many fitness-related traits in eels. we used experimental infections to study the effect of a. crassus on the relative size or mass of organs, and the expression of functionally relevant genes (total of 12 parameters) that are involved in the silvering process of anguilla anguilla. our results showed tha ...201222404329
metals in edible fish from vistula river and dead vistula river channel, baltic sea.metals including al, ba, ca, cd, co, cr, cu, fe, hg, k, mg, mn, na, ni, pb, sr and zn were determined in muscle tissue of 12 fish species by inductively coupled plasma-atomic emission spectroscopy (icp-aes) and cold vapour-atomic absorption spectroscopy (cv-aas). fish were collected from vistula river at lower course and dead vistula river channel in south of baltic sea in poland. the fish species examined include round goby (neogobius melanostomus), crucian carp (carassius carassius), bull-rout ...201222428891
multiple kisspeptin receptors in early osteichthyans provide new insights into the evolution of this receptor family.deorphanization of gpr54 receptor a decade ago led to the characterization of the kisspeptin receptor (kissr) in mammals and the discovery of its major role in the brain control of reproduction. while a single gene encodes for kissr in eutherian mammals including human, other vertebrates present a variable number of kissr genes, from none in birds, one or two in teleosts, to three in an amphibian, xenopus. in order to get more insight into the evolution of kissr gene family, we investigated the ...201223185286
unusual cases of adult intersexuality in the european eel anguilla anguilla.two cases of intersexuality are reported for the first time in european eel, anguilla anguilla (at the beginning of the silver eel stage), within 140 fish caught as glass eels in the south-west of france and reared in tanks at 17°c. cysts containing spermatozoa were observed in ovaries with pre-vitellogenic oocytes. this feature is very uncommon, especially owing to the fact that male cells do not normally reach this stage in captivity, and an environmentally controlled transdifferentation proce ...201223095260
viral diseases of wild and farmed european eel anguilla anguilla with particular reference to the netherlands.diseases are an important cause of losses and decreased production rates in freshwater eel farming, and have been suggested to play a contributory role in the worldwide decline in wild freshwater eel stocks. three commonly detected pathogenic viruses of european eel anguilla anguilla are the aquabirnavirus eel virus european (eve), the rhabdovirus eel virus european x (evex), and the alloherpesvirus anguillid herpesvirus 1 (anghv1). in general, all 3 viruses cause a nonspecific haemorrhagic dise ...201223047193
surviving in a toxic world: transcriptomics and gene expression profiling in response to environmental pollution in the critically endangered european eel.genomic and transcriptomic approaches have the potential for unveiling the genome-wide response to environmental perturbations. the abundance of the catadromous european eel (anguilla anguilla) stock has been declining since the 1980s probably due to a combination of anthropogenic and climatic factors. in this paper, we explore the transcriptomic dynamics between individuals from high (river tiber, italy) and low pollution (lake bolsena, italy) environments, which were measured for 36 pcbs, seve ...201223009661
diverse migration strategy between freshwater and seawater habitats in the freshwater eel genus anguilla.the freshwater eels of the genus anguilla, which are catadromous, migrate between freshwater growth habitats and offshore spawning areas. a number of recent studies, however, found examples of the temperate species anguilla anguilla, anguilla rostrata, anguilla japonica, anguilla australis and anguilla dieffenbachii that have never migrated into fresh water, spending their entire life history in the ocean. furthermore, those studies found an intermediate type between marine and freshwater reside ...201222803719
can a specialist parasite species of a widespread and common host species be rare? the case of spinitectus inermis (nematoda: cystidicolidae) in eels anguilla anguilla.the claim by many authors that spinitectus inermis (zeder, 1800), a narrowly specific parasite of european eels anguilla anguilla (l.), is a rare species is considered at three levels: its geographical range, its frequency of occurrence compared to other eel parasites and its relative abundance in component communities. the parasite is widely distributed in freshwater throughout the european range of the eel but its occurrence is erratic and unpredictable, being known from only 8 countries. surv ...201222779113
variations in the gene expression of zona pellucida proteins, zpb and zpc, in female european eel (anguilla anguilla) during induced sexual maturation.vertebrate eggs are surrounded by an extracellular glycoprotein coat termed zona pellucida (zp). integrity of zp is critical for a correct embryo development. two zona pellucida protein genes (zpb and zpc) from european eel were characterized, specific qpcr assays developed and their expression in immature males and females carried out. an experimental group of silver-stage eel females was maintained at 18 °c and hormonally induced to sexual maturation by weekly injections of carp pituitary extr ...201222750510
in vivo tracking of maturation in male european eel, anguilla anguilla (l.), by computed tomography.the present study aimed in vivo tracking of maturation of male eel by computed tomography (ct). additionally, individually monitored testes sizes were correlated with the conventionally used external maturity indicators (i.e. eye and nose indexes) in order to test and improve their usefulness at individual level. testes could be clearly identified with the ct from the end of the third week of hcg administration routinely used to induce maturation in fish. the volume of testes increased exponenti ...201222695518
fishery-induced selection for slow somatic growth in european eel.both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. we compared body growth rates in european eel (anguilla anguilla) from three mediterranean stocks subject to different fishing pressure. results are consistent with the hypotheses that i) fast-growing individuals are more likely to survive until sexual maturity than slow-growing ones under natural conditions (no f ...201222666373
evolution of microsatellite loci of tropical and temperate anguilla eels.anguilla eels are divided into temperate and tropical eels, based on their major distributions. the present study collected two temperate eels, anguilla japonica and anguilla anguilla, and two tropical eels, anguilla marmorata and anguilla bicolor pacifica, to examine two questions: do temperate and tropical anguilla eels have different genetic polymorphic patterns?; and do temperate anguilla japonica and anguilla anguilla have a closer relationship to each other than to tropical eels? in total, ...201222605978
the temperature challenges on cardiac performance in winter-quiescent and migration-stage eels anguilla anguilla.the present study was undertaken to examine cardiac responses to some of the temperature challenges that eels encounter in their natural environment. the contractile properties of ventricular muscle was studied on electrically paced tissue strips after long term acclimation at 0 °c, 10 °c, or 20 °c, and following acute ± 10 °c temperature changes. the time-course of contraction, and thus maximal attainable heart rates, was greatly influenced by working temperature, but was independent of acclima ...201222587961
quantitative bioassays for measuring biologically functional gonadotropins based on eel gonadotropic receptors.significant declines in eel stocks have been noted in many parts of the world. because eel aquaculture is dependent on wild-caught juveniles, there is a need to achieve artificial reproduction. adult eel maturation is currently induced by repeated injections of purified gonadotropin (human chorionic gonadotropin [hcg]) or pituitary extract. thus the determination of the biological efficacy and quantification of internal levels of gonadotropic hormones is important for optimizing artificial repro ...201222580328
genomics in eels--towards aquaculture and biology.freshwater eels (genus anguilla), especially the species inhabiting the temperate areas such as the european, american and japanese eels, are important aquaculture species. although artificial reproduction has been attempted since the 1930s and large numbers of studies have been conducted, it has not yet fully succeeded. problems in eel artificial breeding are highly diverse, for instance, lack of basic information about reproduction in nature, no appropriate food for larvae, high mortality, and ...201222527267
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